Radiosurgical hypophysectomy has shown promising results and is being investigated as a potential alternative to traditional surgical methods for managing drug-resistant pain in cancer patients. all the described clinical cases, irradiation  was carried out on Gamma-knife. We proposed irradiation on the Cyber Knife in our pilot study

As of now, the prospective pilot study including  three women who were trated for cancer-related pain syndrome between 2020 and 2023. It is important to note that all patients primarily experienced somatic oncological pain syndrome. All patients were assessed for pain with a 100mm visual analogue scale. Moreover, an assessment for  potential endocrine disorders was conducted in all patients both before and after the procedure on a monthly basis.

When performing hypophysectomy using the CyberKnife device, a 5 mm collimator is utilized to ensure maximum radiation selectivity and a high dose gradient outside the target area. During the planning and optimization of the dose distribution, our goal is to cover the entire junction area of the pituitary gland and the stem with the highest doses (100-160 Gy). To achieve this, a target ball with a diameter of approximately 4 mm is positioned in the specified area. In addition, we aim to cover 40-50% of the pituitary gland volume with a dose of 80 Gy, and 2/3 of the pituitary gland volume with a dose of 60 Gy. Furthermore, more than 95% of the pituitary gland volume receives a dose greater than 40 Gy.

To ensure that the target coating remains undisturbed, we optimize the dose loads on critical structures. Typically, the brain stem receives no more than 14 Gy per 90.03 cm3. The dose per 5% (0.035 cm3) of the chiasm can be reduced to 9.3-14.0 Gy, depending on the relative positioning of the target and the chiasm. Other visual pathways generally receive a dose of no more than 10-12 Gy per 5% volume.

The treatment was well-tolerated, with no observed exacerbation of neurological symptoms or radiation toxicity. 

In all cases, an analgesic effect was observed. Although none of the patients were able to completely discontinue painkillers, they all managed to reduce their dose of morphine by 30-50%. Additionally, the frequency of pain breakthroughs decreased for all patients. There was no observed decrease in any of the cases. However, within three months, two patients died from  the underlying disease.

Introduction

Gamma Knife Radiosurgery (GKRS) for trigeminal neuralgia (TN) is effective well established treatment. Treatment effectivness and adverse effects highly depends on fine details of planning protocols not formalized in abstract dosimetric values. That’s why reproduction of treatment results with the other radiotherapy devices including CyberKnife (CK) is not straightforward task.

Materials and methods

42 patients with TN was treated using Gamma Knife (GK). For all patients: Dmax=90 Gy produced with one 4 mm short at 7.5 mm from Brainstem. Integral dose to TN was controlled not increasing with blocking. Proactive follow up was available in 21 patients.

In parallel at the Burdenko Neurosurgery Institute (NSI) 37 patients with TN was treated using CK. GK technique was imitate on planning: 4 mm spheric target was generate at the same position. Proactive follow up was available only in 13 patients.

Results

Resulting BNI pain intensity scale was I-III and IV-V in 15 (71%) and 6 (29%) cases in GK series vs 9 (69%) and 4 (31%) cases respectively in CK series. Numbness or burning appears in 1 and 2 patients respectively in GK series (total 14% adverse events) and 3 and 2 patients respectively in CK series (total 38%). 

Treatment efficiency was the same in GK and CK series but adverse event appears much more often after CK. 

Discussion

We propose 2 reasons for such results. First one is the fact that GK dose fall fast from point of Dmax and has cone-like dose spatial distribution. CK dose was flat on all 4 mm sphere (60-70 Gy on 95% of volume), and has truncated cone-like dose spatial distribution. As result total energy released in TN noticeably less in GK than CK. Other reason is difference in calculation algorithm – GK TMR10 algorithm doesn’t take into account tissues densities in contrast with CK. As results GK plans shows dose larger on few percent than real dose.

Conclusion

TN RS with GK and CK has the same efficiency, but adverse event appears much more often after CK. The reduce Dmax in CK cases by 5-10% compared to GK may be reasonable.

Purpose: to present a curious case of an adult affected by recurrent ependymoma, treated on two occasions with radiosurgery using Gamma Knife.

Material and methods: this is a single case reported in our center of a 36 years old male with no relevant medical history, diagnosed in 2015 with WHO grade II ependymoma. He was treated by subtotal resection and adjuvant radiotherapy to the tumor rest, 54Gy in 30 fractions. It remained stable until 2020, when he presented a local recurrence within the field of radiotherapy that was treated with surgery. In 2021, the initial tumor rest grew up and underwent successful surgical salvage. In 2022, the disease progressed with nodules in the posterior fossa, and radiosurgical treatment with Gamma Knife was performed. On 11/22/2022 he received 12Gy in a single fraction on the 5 lesions, with a volume of 0.067-0.486cc. The main organ at risk was the brainstem, which received >10Gy in a volume of 0.094cc and >12Gy in 0.019cc. During follow-up, the treated lesions responded and decreased in size but a new nodule appeared outside the previous treatment field, so a new treatment with Gamma Knife was decided, administering 16Gy in a single fraction on 11/7/2023 to a tumor volume of 0.12cc. All organs at risk were respected.

Results: tolerance to treatment with radiosurgery was excellent, presenting only acute toxicity consisting of grade 1 headache that resolved with first step analgesia, without presenting late toxicity for the moment. After more than one year of follow-up, the five lesions initially treated have achieved a response consisting of a decrease in size. The last lesion is still pending reevaluation. Eight years after diagnosis, the patient remains clinically stable and maintains a good quality of life.

Conclusions: ependymomas are an infrequent group of glial tumors specially uncommon in adults, where outcome datas are limited. Ependymomas are associated with significant risk of recurrence and long-term prognosis for these patients is poor. Due to the location and recurrent nature of the lesions, their treatment is still a real challenge today. This case is an example of the safety and effectiveness of treament with radiosurgery using Gamma Knife, even in the context of a second re-irradiation, allowing multiple consecutive treatments to be administered.

Objective

Trigeminal neuralgia (TN) is a well-known facial pain disease that has been shown to have difficult control with high recurrence rates after medication, surgical decompression (MVD) and ablation. Gamma Knife Radiosurgery (GKRS) is a treatment modality where a focused high-dose radiation is delivered to the trigeminal nerve. It has become the best treatment alternative after MVD for uncontrollable pain and the main option after failure or recurrence. It has a response rate of 76-92%, with a durability that can reach 4.9 years, with recurrence rate of 30-40%. We present the result of a 24-years’ experience with repeated GKRS for hard-to-treat TN.

Methods

A single-institution retrospective analysis, from 1998 to 2023, of TN cases treated with GKRS and their need for re-treatments for pain control. Indications for re-treatment were: uncontrolled pain; controlled pain with medication but intolerable side-effects; recurrence after initial response; no pain improvement after treatment; patient choice of GKRS over other treatment modalities. All patients were evaluated on BNI pain scale prior and after each treatment, pain characterization between typical and atypical, evaluation of TN type, time interval between treatments, prescription dose and reported side-effects.

Results

Of the 206 patients treated with GKRS, 51 (24,8%) needed additional GKRS, of those, 8 (15,7%) needed 3 treatments for pain control. No patients were treated more than 3 times. Of the retreated patients, 20 were Type II, 10 being secondary to MS and the others due to tumor compression. One patient with MS and 1 with tumor compression needed 3 GKRS. Only 2 patients initially presented with atypical pain but 7 changed from typical to atypical after the first GKRS and 8 after the second. No patients presented this change after the third procedure. The time interval between the first and second treatment had a median of 3 years and between the second and third of 6 years. After the first treatment, BNI improved from a median of 4 to 3b, the same results were noted with the second treatment and, after the third, it improved from 4 to 2. The median doses were 72Gy, 66.5Gy and 70Gy respectively. No adverse radiation effects were reported.

Conclusion

GKRS has been used for TN since its development and has had its use increased as a primary or secondary treatment option. We report a 24-year experience of a single high-volume center that shows the visibility, efficiency, and safety of repeating GKRS for hard-to-treat TN.

Objectives: The thalamus plays a key role as a brain relay, significantly influencing motor and sensory signals through cortical-subcortical pathways. Targeting and lesioning the posterior part of the central lateral nucleus (CLp) in the thalamus is thought to affect pain in multiple ways; however, thalamic subregions are not clearly visible using standard MRI techniques. As a result, CLp targeting methods depend on indirect techniques, which often fail to consider individual differences in anatomy. Therefore, standardizing this targeting process is critical for improving treatment planning. This technical study evaluated the integration of thalamic nuclei segmentation in Gamma Knife treatment planning for chronic pain.

Methods: Ten healthy participants without structural abnormalities underwent T1-weighted high-resolution structural MRI, and subcortical segmentation was performed using FreeSurfer software (version 7.4.1). Detailed segmentation was performed with a probabilistic atlas of the thalamic nuclei built with histological data. Label images were then converted into a DICOM form as 3D label objects, and these objects, along with the associated T1-weighted image, were imported into GammaPlan. A single 4-mm isocenter was placed on the CLp using an indirect targeting method based on stereotactic brain atlases.

Results: The data from 10 participants (5 males, 5 females, aged between 25 and 60 years) were analyzed. All segmentations were confirmed to accurately delineate the subregions of the thalamus. In cases with atypical thalamic structures and where the indirect coordinates alone would have been less reliable, the pre-segmented thalamic maps provided a critical visual reference. 

Conclusions: Our observations suggest that incorporating thalamic segmentation into the radiosurgical planning process could be a valuable tool in enhancing the accuracy of indirect targeting methods. This is particularly relevant in patients with anatomical variations, where deviations from standard thalamic morphology could otherwise lead to inaccuracies in targeting.

Background

Sphenoorbital meningioma (SOM) is a unique and uncommon subset of skull base meningiomas. Optic nerve involvement and visual impairment are not uncommon. For tumors in close contact with the optic nerves, it is very difficult both to preserve vision and inhibit tumor progression by remaining within safe dose ranges, especially for single fraction stereotactic radiosurgery (SRS). To achieve this, it is essential to perform radiosurgical planning with the utmost caution. We report radiosurgical planning, implementation, and the long-term results of SRS to manage a SOM surrounding the optic nerve.

Methods

In January 2011, a 54-year-old woman was examined in another center for headache and referred to our outpatient clinic for SRS after being diagnosed with SOM. Her neurologic examination, including normal visual acuity and visual field, was unremarkable. Magnetic resonance imaging (MRI) revealed a left SOM surrounding the left optic nerve. Stereotactic radiosurgery was performed using a Leksell G frame (Elekta, Sweden), MRI-guided dose planning, and the 4C model Gamma Knife unit. Radiosurgical planning was carefully tailored to spare the left optic nerve. The tumor was treated with a 10 Gy prescription dose to 50% isodose line.

Results

The patient’s postoperative course was uncomplicated, and her headaches gradually improved over the course of the next 6 months. MRI showed tumor volume regression at 12 months. Twelve years after radiosurgery the patient is symptom free and has not had any further progression of tumor.

Discussion

The main goal in both surgical and radiosurgical treatment of perioptic tumors is to manage the tumor without causing or increasing vision loss. A crucial step in SRS is the evaluation of treatment plans, which affects the features of the plan chosen for treatment and, subsequently, how radiotherapy patients are treated. The process involves creating a detailed map of the target area, determining the optimal radiation dose and delivery technique, and considering patient-specific factors such as anatomy and any previous treatments. Accurate planning helps maximize the therapeutic benefit and minimize the risk of adverse effects.

Conclusion

SRS provides a minimally invasive treatment option as an alternative to surgical resection, particularly for tumors that are challenging to access, close to vital structures, and patients with contraindications to surgery. This case demonstrates the unique technical importance of radiosurgical planning in managing a challenging neurosurgical task with long-term effectiveness and safety.

Introduction

Sphenopalatine ganglion is a target for Leksell gamma knife (LGK) radiosurgery in cluster headache in patients who failed conservative treatment. Only a few studies present this therapeutic approach and outcomes are inconsistent. The target identification and treatment parameters are still unclear. The aim of this study is to analyze data from patients with cluster headache who underwent LGK radiosurgery treatment and evaluate the efficacy and safety of this therapeutic approach.

Methods:

We enrolled 36 patients (15M, 21F; mean age 48y) with diagnosed cluster headaches. All patients underwent a radiosurgical irradiation of sphenopalatine ganglion using the Leksell gamma knife (model C, Perfexion, and ICON).  We used a single 4mm shot, and the mean Dmax was 85.3Gy (80-90Gy).

Results

The pain reduction was achieved in 24 patients (66%) and the intensity of pain was reduced to 42% of the previous pain level on average. The mean time to pain reduction was 53 days (3-180). In 12 patients (50%) the effect was temporary, and the mean time to recurrence was 22 months (1-120). In 5 patients with pain recurrence, repeated Leksell gamma knife treatment was done with no longtime lasting effect. The mean follow-up was 35 months. No adverse event was observed.

Conclusion

Leksell gamma knife irradiation of the sphenopalatine ganglion is a safe and effective method for pain reduction in cluster headache.  Two-thirds of patients experienced pain reduction; in one-third, the pain reduction was permanent.

Treating brainstem metastases can be challenging for the multidisciplinary team involved.

Due to its location, surgery is not an option. Therefore, radiation is the best solution in these cases, with the concern of potential toxicity in such a sensitive structure. The goal of treatment is to ensure safety and efficacy while preserving the patient's quality of life.

In October 2022, the first patient with a diagnosis of brainstem metastasis was treated by a dedicated group of stereotactic radiosurgery in our department, which began its clinical activity in 2021.

We presented a case of a 59-year-old male patient who had a solitary brainstem metastasis from non-small cell lung cancer without any other extracranial disease. The patient presented with diplopia and occipital headache as initial symptoms, which were controlled with steroids. The diagnostic MRI conducted in September 2022 showed a solitary lesion localized in the midbrain with a large dimension of 10.4 mm with marginal oedema.

He had an ECOG-Performance Status score of 0. In addition, the Neurologic Assessment in Neuro-Oncology Scale and the Mini-Mental State Examination were performed. The Lung Ds-Graded Prognostic Assessment (Lung-molGPA) calculated an estimated median survival of 26.5 months.

The patient underwent fractionated stereotactic radiosurgery in October 2022. The immobilization device used was an open mask for surface image-guided radiation, in accordance with our institution's protocol. Planning involved fine slice CT scans (1mm) and MRI (1mm) with contrast injection. Geometric distortion correction was applied during the MRI planning process. A GTV of 0.25cc and a PTV margin of 1mm were delineated, along with critical organs at risk. Constraints were based on the recommendations of the American Association of Physicists in Medicine Task Group 101.

The total prescribed dose was 21 Gy administered in 3 fractions. The maximum dose to the brainstem was 25 Gy (in GTV: 119.9%), with a maximum of 23 Gy in the brainstem minus PTV. Treatment was delivered using volumetric modulated arc therapy on a linac. Plan evaluation parameters included Paddick conformity index, conformity index, selectivity index, homogeneity index, and gradient measure, with values of 0.93, 1.07, 0.77, 0.15, and 0.34, respectively.

No toxicity has been observed during or after treatment thus far, and the patient is no longer receiving steroid therapy. In October 2023, the patient underwent an MRI which showed a complete response after 12 months of treatment. Serial MRIs are being conducted every 2 months as per institutional protocol for follow-up.

Background:

   Microvascular decompression of the trigeminal nerve is an effective procedure for treating patients with trigeminal neuralgia (TGN). However, vertebrobasilar decompression involves technical difficulties and demonstrates a higher risk of minor trigeminal hypesthesia/hypalgesia, transient diplopia, and hearing loss. Stereotactic radiosurgery (SRS), mainly using Gamma Knife (GK), has been an effective alternative treatment for TGN. Few studies reported the treatment results of SRS for TGN caused by vertebrobasilar compression. This report presents the treatment results of GK-SRS in four TGN cases.

Materials and Methods:

   GK-SRS was performed for TGN due to vertebrobasilar compression in four patients, including two males and two females, aged 67-90 years. The maximum dose of 80 Gy was delivered at the retrogasserian portion of the ipsilateral trigeminal nerve root.

Results:

   All four cases with TGN achieved relief in 4-10 months after GK-SRS. However, TGN recurred 41 months after GK-SRS in one of the four cases. A second GK-SRS at the root entry zone at a maximum dose of 70 Gy relieved pain again 10 days after the second GK-SRS. TGN in another case among the four partially recurred in 3 years but did not deteriorate until the patient died from old age 62 months after GK-SRS. The other three cases, including the one with repeat GK-SRS, were alive with complete TGN remission at the end of follow-up of 20-52 months. GK-SRS-related adverse effects were not observed in any case.

Conclusions:

   GK-SRS was a safe and effective treatment in all four TGN cases due to vertebral artery-basilar artery compression, although a second treatment session was added again for pain recurrence in one of the four cases.

Background: Gamma Knife stereotactic radiosurgery (GK-SRS) is considered for treatment of disabling pharmacoresistant tremor in various movement disorders mainly as unilateral Vim-thalamotomy. Advantageously, GK-SRS may be performed in patients with severe concomitant diseases or requiring constant anticoagulants, and in patients with implanted neurostimulator. Its limitation is impossibility of neurophysiological control and intraoperative testing of clinical and side effects, as well as delay in their appearance.

Objective: To study efficacy and safety of GK-SRS unilateral Vim-thalamotomy in patients with different tremor.

Methods: 12 patients underwent GK-SRS (Parkinson’s disease – 9 patients, post-stroke tremor – 1, essential tremor – 1, post-traumatic tremor – 1). Mean age was 66.4±14.3 years. In 3 PD-patients, GK-SRS was performed aiming additional tremor management after previous stereotactic interventions (radiofrequency Vim-thalamotomy on the other side, STN-DBS with remaining tremor on dominant side, and explantation of Vim-DBS). Tremor severity in patients with parkinsonism was assessed by UPDRS-subtests, in other cases – by Fahn‐Tolosa‐Marin CRST-subtests. Radiation dose was 130Gy.

Results: In PD-group, outcome was assessed in 7 patients. In short-term follow-up (0.5–1 year), tremor reduction in the contralateral extremities according to UPDRS-subtests was >50% in 4 patients, >25% – in 2 patients, and <25% – in 1 patient. At the same time, functional improvement was observed in 71%. In 5 PD-patients, long-term follow-up was available (1.5–5 years) demonstrating stable GK-SRS effect on tremor. Upon further observation, most PD-patients showed gradual increase in severity of motor and/or non-motor PD-symptoms due to disease progression, which had a negative impact on daily living activities.

In a patient with levodopa-responsive post-stroke tremor, a significant decrease in tremor severity was observed approaching 60% by 6 months after GK-SRS and 90-100% in long-term follow-up until 9 years. Levodopa equivalent daily dose was reduced from 2650 to 250mg.

In a patient with ET, one year after GK-SRS, severity of postural and kinetic tremor in the contralateral arm decreased moderately (25% according to FTM-CRST), accompanied by some improvement in function.

In a patient with post-traumatic tremor, improvement was 58% (FTM-CRST) by the second year.

There were no side effects associated with GK-SRS.

Conclusion: Outcomes of GK-SRS thalamotomy are heterogeneous. Most patients receive meaningful reduction in tremor severity without marked side effects. 20-30% of patients may have insufficient clinical effect. This may be due to inability of direct Vim visualization, lack of neurophysiological verification of the target and intraoperative testing, and presence of hypo- and hyperresponders to radiosurgical intervention.

INTRODUCTION: The aim of this study is to present the methodology and the results of a truly Patient-Specific Quality Assurance (PSQA) process via the RTsafe-PseudopatientTM service (RTsafe P.C.) for a challenging Stereotactic Radiosurgery (SRS) treatment of a multiple brain cavernomas case. The treatment was implemented at the Neuro Spinal Hospital, Dubai, UAE using CyberKnife M6 (Accuray Inc.).
MATERIALS AND METHODS: A female patient with multiple brain cavernomas was treated with CyberKnife robotic radiosurgery in our center. Planning CT with 1mm slice thickness was co-registered with T1 with contrast and T2 MRI scans to identify four deep seated, surgically unrespectable, cavernomas. Treatment plans were devised employing fixed collimators (5mm, 7.5mm) for four brain cavernomas. A RTsafe - PseudopatientTM patient-specific head phantom was built by RTsafe P.C., (Athens, Greece) for the selected patient, using as input the patient’s anonymized planning CT scan. The patient's head replica, filled with polymer gel as a 3D dosimeter, was precisely positioned using the same immobilization devices used for the patient's actual setup. PSQA plans were executed using the 6d skull tracking method as in the actual delivery on the patient. Subsequently, a T2 MRI scan of the phantom was obtained (1.5T Aero SIEMENS) 24 hours post-irradiation. Polymerization degree after irradiation is proportional to the dose delivered at each point of gel’s volume. The phantom's MRI scan and the calculated GelDose were registered with the patient's DICOMRT dataset. PSQA was assessed through 3D Gamma Index analysis with passing criteria of DTA(1.5mm)/DD(2%)/DT=1%.
RESULTS: Evaluation was conducted for four targets, revealing a mean GI passing rate of 97.3% (min=95.9%, max=98.6%). This indicates a high level of dosimetric and 3D spatial accuracy of dose delivery, ensuring the safety and effectiveness of the treatment
DISCUSSION:  Verification of dose distributions on 3D printed patient's anatomy is achieved through 3D dosimetry employing the Polymer Gel Dosimeter. This method ensures submillimeter spatial and dosimetric accuracy, making it particularly well-suited for Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). The Polymer Gel Dosimeter exhibits no directional dependence, offering consistent and reliable results from all angles. Moreover, plans are summed on the gel phantom enabling comprehensive assessment of the total dose distribution in the treatment of multiple lesions. This summation approach provides a holistic view, enabling effective verification of the overall dose delivery across various treatment targets.

INTRODUCTION

Severely impaired patients with obsessive and compulsive disorder (OCD) may remain refractory to medical and behavioral treatments. These patients may benefit anterior capsulotomy using radiosurgery. We evaluated the safety and efficacy of Cyberknife radiosurgery in intractable patients with OCD.

METHODS

At our center, we treated 20 consecutive patients with intractable OCD using Cyberknife Robotic Radiosurgery between February 2014 and June 2022. Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Beck Anxiety Scale and Beck Depression Scale were used before the treatment and in the follow-up. Bilateral radiosurgical capsulotomies were performed using targets at the midputaminal point of the anterior limb of the internal capsule. Median prescription dose to the target margin was 80 Gy (range, 70-95 Gy) for each side. 

RESULTS

Median follow-up time was 55 months, ranging 12 to 100 months. In three patients, a second treatment was performed due to lack of bilateral lesions 7,8 and 10 months after initial procedure. Patients tolerated the procedure well without significant acute adverse events. Two patients developed edema and cyst formation on one side that required medical treatment but not surgical intervention. Thirteen patients (65%) showed marked clinical improvement which is defined as at least 35% reduction in Y-BOCS score.

CONCLUSIONS

Bilateral anterior capsulotomy using Cyberknife radiosurgery may be a safe and effective treatment in patients with intractable OCD.

Introduction:

Meningiomas are the most common dural masses, but other neoplastic lesions can sometimes mimic them. In these cases, because of differential diagnostic difficulties, inappropriate findings can lead to inadequate medical treatment. Here, we present the case of our patient, whose initial medical investigations led to a failed result.  

Patient's history

A 66-year-old female with a former 14-year oncologically stable breast cancer history applied for medical examination because of dizziness, severe headache, and left-sided facial pain. After one month, complete peripheral facial paresis appeared without hearing complaints. Imaging revealed a left-sided parasellar mass with a tiny contrast-enhancing tissue in the internal auditory canal. That last was diagnosed as an en-plaque propagation of the parasellar tumor that could be a meningioma. Contrary to the first opinion of the radiologist, and due to the cancer history, we were convinced that the visible lesions were not else than leptomeningeal dissemination of the cancer. Complete oncological restaging was initiated, including staging CTs, lab tests, and liquor screening. To our surprise, at that time, no tumor was found outside the intracranial space, so we accepted the diagnosis of meningioma that the radiologist had suggested before. 

Treatment:

Stereotactic irradiation of tumor mass was performed with a 13Gy at 50% marginal dose. 

Result:

Follow-up MRI was performed after 3 and 6 months. The regression of the lesion was visible, but clinically there was no improvement. 

The headache was almost uncontrollable, and generally, the patient had poor general conditions. Several lab tests, lumbar puncture, and staging CTs were repeated, but with negative results. So observation and general medication were continued. Further MRI after 2 months showed a remarkable change. Strong leptomeningeal contrast enhancement appeared with some leptomeningeal nodules. An open-skull biopsy was performed. This was the first examination that could verify our initial suspicion. So the diagnosis after the histology was modified to leptomeningeal dissemination of previous breast cancer that was mimicking meningioma. After several months, the patient passed away. Finally, the autopsy confirmed the highly disseminated cancer disease, but no intracerebral metastasis was found, only dural lesions. 

Conclusion:

Considering the results of the initial investigations, which suggested a meningioma, stereotaxic radiosurgery seemed to be an appropriate choice. We could not recommend whole brain irradiation at the beginning, since leptomeningeal dissemination could not be verified by any procedure at that time.

However, in the case of leptomeningeal dissemination, whole-brain irradiation would have been the only right choice.

Introduction

Radiosurgery Cingulotomy is underutilized for refractory neuropathic pain (RNP). We reviewed three patients of RNP with allodynia and dysesthesias treated with bilateral Icon Gamma-Cingulotomy (IGKCi) who had failed multiple pain surgeries.

Methods

IGKCi used double 4mm shots of 120 Gy on each side. Coordinates were 7mm from midline, 7mm above the roof of the lateral ventricles for the first shot, and 20-25mm posterior to the lateral ventricles anterior wall. Tractography by artificial intelligence (Brainlab-Elements, Germany) turned into objects transported to the Gamma-Plan (Elekta, Sweden) demonstrated the cingulate gyros span, defining the site of the second shot. Sided-by-side anteroposterior shots center distance offset decreased the high dose to branches of the anterior cerebral arteries.

Results

Patient one, a 53-year-old woman had left V2-V3 trigeminal neuralgia (TN) for 15 years. This is after microvascular decompression (MVD), balloon compression (BC), upper cervical dorsal column stimulation (SCS-trial), and deep brain stimulation (DBS). Her RNP involved the left hemi-cranium. Dependence on high opioid doses and frequent visits to the emergency room (ER) led to bilateral IGKCi. Additionally, she received 90 Gy to the root entry zone of the left trigeminal nerve on the same day. She stopped opioids and visits to the ER three months after the procedure, she developed asymmetric radiation reaction with edema without symptomatic repercussion. At 18 months follow-up, her visual digital scale for pain (VAS) fell from 10 to 2. Patient two, a 56-year-old woman, with tetraparesis since she was 14 months. She underwent numerous spine deformities and renal surgeries. Her RNP involved her legs and lower back, she also complained of generalized body pain. She did not accept traditional neuromodulation techniques, opting for bilateral IGKCi. At four months follow-up she stopped opioids, her pain improved more on the right side, persisting on the left, VAS fell from 10 to 5. She continues working as a librarian. Patient three was a 36-year-old woman with left TN, failure of MVD, balloon compression, and DBS. She also developed RNP. She required an intensive care unit for pain control and had multiple admissions through the ER. At nine months follow-up after IGKCi she stopped regular use of opioids and hospital admissions. She reports a VAS decrease from 10 to 7.

Conclusion

Neuromodulation using IGKCi maximal dose of 120 Gy, aided by tractography placing double shots on each cingulum affords a substantial decrease of pain and need for opioids.

Introduction

GammaKnife radiosurgery (GKRS) is a valuable modality for the treatment of trigeminal neuralgia. However, the durability of response and the factors predicting response remain somewhat unclear. 

Methods

This study was a retrospective analysis of a prospectively maintained database spanning the years 1998-2022 (inclusive). Demographic and medical details were obtained from the electronic medical records (EMR). Plan parameters, dose delivered, morphometric data pertaining to the nerve and brainstem, etc. were obtained from the imaging sequences in Gamma Plan. Follow up details were also obtained from the EMR. Differences between patients who responded and those who did not were analyzed.

Results

A total of 206 patients were treated over the study period; 155 patients had received single treatments and 51 had received more than 1 treatment for the same side. The right side was more commonly affected than the left (58% vs 42%) and women were more frequently affected than men (68% vs 31%). For patients who had received a single GKRS treatment, the mean follow up was 908 (±1218) days. At last follow up, 61.5% had significant pain relief and 19.3% had adequate pain relief; overall 71% were pain free, on or off drugs, after treatment. Based on any change in BNI scores at last follow up, 85% responded to treatment, 11% did not respond and 4% were worse off than before GKRS. More men (90%) than women (76.5%) had pain relief (p=0.03). The mean weight and BMI were higher for those who responded to GKRS than those who did not. The presence or absence of a conflict did not affect response to GKRS. However, patients with venous conflicts were more likely to respond to GKRS (88%) than those with arterial conflicts (80%) or both (54%, p=0.016). The site of shot placement (nerve vs conflict) did not affect response rates, nor did the dose to the root entry zone. For patients who required multiple treatments, those with right sided pain were more likely to respond (93%) than those with left side pain (72%). Optimal visualization of the affected nerve led to better pain free rates (p=0.04).

Conclusions

GKRS for trigeminal neuralgia results in a good response rate with more than 70% of the patients being pain free, on or off drugs. Various modifiable and non-modifiable factors could influence the outcome of GKRS for trigeminal neuralgia. 

Introduction

Radiation treatment plans for essential tremor (ET) are executed in two steps: defining the ACPC line and then, applying linear shifts from the PC point. 25-30% ACPC length anterior, 11-15 mm lateral and 2-4 mm superior, aiming for the ventralis intermediate nucleus (VIM) and establishing the target coordinate.

Objective

Verify the capability of Brainlab Elements Trajectory to automatically define the Anterior Commissure – Posterior Commissure (ACPC) line in T1 MRI in ET treatment cases.

Method

We analyzed data from 13 essential tremor cases treated in a Leksell Gamma Knife Icon (LGKI). The plans were created using Elekta Gammaplan (GP), with the ACPC line defined in a T1 MRI by the attending neurosurgeon and double-checked by the attending radiation oncologist. From the PC point, shifts were applied to reach the treatment target. Two shots were placed in the same coordinate, 4 mm collimators open with two sectors closed each [2,6 (Left cases) or 4,8 (Right cases) and 7,3 (both cases)] to generate a more shaped isodose of 50%. The Diffusion Tensor Imaging (DTI) MRI with 32 directions sequence was used to define the pyramidal tract (PT) as an OAR in Brainlab Elements Fiber Tracking, the VIM was also defined by Brainlab Elements, and the structures exported do GP.

In Brainlab Elements Trajectory, the same T1 MRI sequences were loaded and the ACPC line was defined automatically by the software without any adjustments. The same shifts from the reference plan, in mm, were applied from PC point setting a new target. Shots were adjusted to the new coordinate.

Results

Elements sets a shorter ACPC line (23,0 ± 1,5 mm) than the experts (25,9 ± 1,6 mm). In terms of distance from the target to the center of mass of the VIM, the software could match the experts’ result (2,7 ± 1,4 mm) with an average of (2,8 ± 1,1 mm). Dose in the PT were also comparable, 10,7 ± 4,8 Gy for experts and 9,4 ± 4,1 Gy for the software. Mean dose to VIM of 37,0 ± 10,4 Gy for experts and 40,6 ± 12,4 Gy for Elements and V_{70 Gy} in VIM of 33,2 ± 12,9 Gy for experts and 29,2 ± 18,9 Gy for Elements.

Conclusion

Elements is capable of auto define an ACPC line. With a 12% shorter ACPC line there was not statistically significance difference in any other dosimetric or geometric parameter analyzed.

Background

Close to 100 million people worldwide suffer the sequelae of severe trauma or hereditary impairment of the brain or spinal cord, with spasticity and related pain being a common long-term complication in survivors. Conventional surgical treatments are effective but available to a limited number of patients.

Aim

A novel non-invasive treatment for spasticity, stereotactic radiosurgery (SRS) of the sensory component of selected nerve roots, is here reported. This treatment is the radiosurgical equivalent of selective dorsal rhizotomy, a procedure of well-known efficacy.

Methods

Four patients with refractory spasticity and related pain associated with trauma or injury to the brain and/or spinal cord underwent stereotactic irradiation of selected cervical or lumbar roots. Treatment was delivered to the post-ganglionic sensory segment of cervical roots or to the dorsolateral sensory region of lumbar roots. Selection of irradiated roots was based on somatotopic distribution of spasticity and related pain as well as EMG findings. Pre- and post-procedure spasticity and pain levels were assessed with Modified Ashworth Scale (MAS) and Visual Analogue Score (VAS).

Results

The treatment was well tolerated. Marked symptomatic relief of spasticity and pain was found in all patients. After 2 years, median reduction of MAS score was 50%. Mean reduction of MAS & VAS were, respectively, 43.7% & 64.3%.

Conclusions

SRS of spinal nerve roots appears to be a safe, effective, and noninvasive treatment for patients with spasticity & pain caused by brain or spinal cord injury. This technique provides a useful option for the treatment of a wide variety of patients suffering from long-term sequelae of neurological injury and can broadly expand the ability to treat patients currently orphaned of treatment.  

Given the treatment’s remarkable results, we developed and have initiated a randomized, sham-controlled clinical trial to assess the efficacy of the treatment in the most rigorous fashion possible. Twenty-two patients will be randomized to treatment vs sham with blinding of the patient and raters. The trial is powered for an 80% power of detecting 50% reduction in MAS, the primary outcome. Secondary outcomes include adverse events and quality of life. At the time of submission, 3 patients have enrolled.

Introduction.

Oncological abdominal pain due to celiac plexus compression or infiltration, is often severe and difficult to treat with current approaches including opioid analgesics, nerve block or neurolysis, chemotherapy and conventional radiation therapy. Emerging no invasive treatment modalities such as Stereotactic Body Radiation Therapy for the celiac plexus are being studied in order to treat this complex pain syndrome.

Methods.

Patients with classic celiac abdominal pain (Visual Analogue Scale >5) and decreased in the quality of life related to oncological malignancies, even with the optimal use of opioids and estimated survival of at least 30 days were included. All patients were simulated in 3D CT scan using ALTA® Qfix with vacuum bag, abdominal compression, and oral contrast. Two millimeters slice thickness images were acquired from T8 to L5-S1 vertebral space and transferred to TPS(Eclipse®). Celiac plexus was contoured (anterolateral aspect of aorta) from T12 to L2 plus/minus adjacent tumor. Organs at risk and constraints were based upon AAPM Task group 101. The primary endpoints were reduction of pain (>50%) before 3 weeks (best case scenario before 72 hours) and quality of life (QoL) improvement.

Results.

From October 2022 to July 2023, 4 patients were treated (75% pancreatic cancer, 25% gallbladder) with ring gantry lineal accelerator (HALCYON™). Mean age= 68 years {59-80}.  Prescribed dose was 25Gy/1 fraction (3 patients) and 45Gy/5 fractions (1 patient) to the celiac plexus, using uniform dose technique. Adjacent tumor was treated in 3 patients. Mean celiac plexus volume= 28.8cc {22.31-39.58}, Mean tumor volume= 36.6cc {20.68-51.59}.  Volumetric Arc Therapy (RapidArc®) with 6 MV energy plans were calculated to deliver SBRT. Due to Halcyon™ monitor units (UM) it was necessary to use 8 to 15 arcs. Mean treatment time=11.28 minutes {5-16.74}. Mean follow up=8 weeks {4-13}. All patients had relief of pain ≥ 50% before 72 hours post treatment and QoL improvement.

Conclusions.

This first experience in Central America using SBRT to the celiac plexus, demonstrated that this treatment modality is feasible and safe for palliative treatment in oncological abdominal pain, with early response observed in the decrease of pain probably associated to the neuromodulation effect.

Background: Gamma capsulotomy is an established neurosurgical procedure for refractory psychiatric disorders. However, radionecrosis is a serious complication associated with this intervention. This report presents a rare case of severe, steroid-refractory bilateral radionecrosis in a 26-year-old male patient following bilateral ventral anterior limb internal gamma capsulotomy, which showed a remarkable response to Boswellia serrata. Boswellia serrata is a traditional herbal extract with potent anti-inflammatory properties, and has recently gained attention for its potential role in mitigating radiation-induced cerebral edema and radionecrosis in oncological treatments. Here we showcase its effect in a non-oncologic treatment.

Case Description: The patient, a 26-year-old male with a history of severe obsessive compulsive disorder, underwent bilateral ventral anterior limb internal gamma capsulotomy (80Gy @ 50%IDL, bilaterally). Post-procedure, his OCD improved (YBOCS 33 -> 28) but he developed severe bilateral radionecrosis. Initial management with steroids failed to yield any improvement, and caused severe weight gain and hallucinations in the patient.

Intervention and Outcome: Given the challenges with conventional steroid therapy, the patient was commenced on oral Boswellia serrata 2400mg BID. Subsequent imaging revealed significant improvement and then complete resolution of radionecrosis, leaving only intended gliosis at the site of the prescription isodose line. No significant side effects of Boswellia serrata were observed during the treatment course.

Discussion: This case highlights the potential efficacy of Boswellia serrata in managing severe, steroid-refractory radionecrosis post-neurosurgical interventions. The positive outcome in this case suggests the need for further exploration into alternative treatments like Boswellia serrata, especially in cases where conventional therapies fail or are not viable.

Conclusion: Boswellia serrata can be a viable alternative for treating steroid-refractory radionecrosis following functional radiosurgical procedures. This case underscores the importance of considering novel therapeutic approaches in complex clinical scenarios. Further studies are warranted to establish its efficacy and safety profile in a broader patient population.

Background and Objectives

Trigeminal Neuralgia (TN) affects about 2% of multiple sclerosis (MS) patients and often shows higher rates of pain recurrence after treatment. Previous studies on the effectiveness of stereotactic radiosurgery (SRS) for TN did not consider the different MS subtypes, including remitting relapsing (RRMS), primary progressive (PPMS), and secondary progressive (SPMS). Our objective was to investigate how MS subtypes are related to pain control (PC) rates after SRS.

Methods

We conducted a retrospective multicenter analysis of prospectively collected databases. Pain status was assessed using the BNI Pain Intensity Scales. Time to recurrence was estimated through the Kaplan-Meier method and compared groups using log-rank tests. Logistic regression was used to calculate the odds ratio.

Results

258 patients - 135 (52.4%) RRMS, 30 (11.6%) PPMS, and 93 (36%) SPMS were included from 14 institutions. 84.6% of patients achieved initial pain relief, with a median time of one month. 78.7% had some degree of pain recurrence with a median time of 10.2 months for RRMS, 8 months PPMS, SPMS 8.1 months (p=0.424). Achieving BNI-I after SRS was a predictor for longer periods without recurrence (p=0.028). Analyzing pain control at last available follow up, and comparing to RRMS, PPMS was less likely to have pain control (OR = 0.389; 95% CI 0.153-0.986; p=0.047) and SPMS was more likely (OR=2.0; 95% CI 0.967-4.136; p=0.062).

A subgroup of 149 patients did not have other procedures apart from SRS. Median times to recurrence in this group were: 11.1, 9.8, and 19.6 months for RRMS, PPMS, and SPMS, respectively (log rank, p = 0.045).

Conclusion

This study is the first to investigate the relationship between MS subtypes and pain control following SRS, and our results provide preliminary evidence that subtypes may influence pain outcomes, with PPMS posing the greatest challenge to pain management.

Background

Glioblastoma (GBM) is the most common primary brain tumor with poor patient prognosis. Spinal leptomeningeal metastasis has been rarely reported, with long intervals between the initial discovery of the primary tumor in the brain and eventual spine metastasis.

Observations

Here, the authors present the case of a 51-year-old male presenting with seven days of severe headache, nausea, and vomiting. Magnetic resonance imaging of the brain and spine demonstrated a contrast-enhancing mass in the pineal region, along with spinal metastases to T8, T12, and L5. Initial frozen-section diagnosis led to treatment strategy for medulloblastoma, but further molecular analysis revealed characteristics of IDH-wild type, grade 4 GBM. CyberKnife radiosurgery was utilized for treatment of the pineal tumor and the three spinal metastases at T8, T12, and L5. Concurrent use of radiosurgery, craniospinal radiation, and chemotherapy helped with overall stability of the pineal mass. 

Lessons

Glioblastoma has the potential to show metastatic spread at time of diagnosis. Spinal imaging should be considered in patients with clinical suspicion of leptomeningeal spread. Furthermore, CyberKnife radiosurgery should be considered in treatment options and planning for late-stage glioblastoma. Molecular analysis should be confirmed following pathological diagnosis to finetune treatment strategies.

Background

Secondary trigeminal neuralgia occurs in up to 15% of patients, with multiple sclerosis being one of the identified possible causes. The natural progression of the disease often leads to refractory control of symptoms, requiring specialized procedures due to medical treatment failure.

Lovo et al. published a case series in May 2022, treating eight patients with radiosurgery for severe trigeminal neuralgia pain crisis. The affected trigeminal nerve received a dose of 80 to 90 Gy, and an additional target was defined in the contralateral centromedian nucleus of the thalamus, receiving a dose of 120 to 140 Gy. A 25% complete pain resolution rate at 24 hours and an 87.5% pain improvement rate >50% at 48 hours post-treatment were reported. No adverse events were reported in a median follow-up of 135 days.

Case summary

A 45-year-old male with a 15-year history of diagnosed multiple sclerosis treated with natalizumab presented with a 5-year history of severe right-sided trigeminal neuralgia pain episodes.

The patient had previously been managed with neuromodulators and microvascular decompression surgery, achieving partial control.

In October 2022, the pain worsened, with daily refractory pain paroxysms rated as 10/10 on the visual analog scale (VAS). The case was discussed in the radiosurgery unit, and it was decided to offer SRS treatment using the CyberKnife M6 system with dual targeting. The patient received 90 Gy to the retrogasserian zone of the affected trigeminal nerve and 120 Gy to the contralateral centromedian nucleus of the thalamus in a single session.

Following treatment, the patient was monitored using the VAS. At 24 hours: VAS 6/10; at 72 hours: VAS 3/10; at 8 days post-treatment: VAS 0/10. The patient was contacted by phone every 3 months, with the latest update in January 2024 confirming continued pain relief and no need for neuromodulators. The patient has been pain-free for 14 months until now, with no toxicities reported.

Conclusion

Dual-target SRS may be considered for complex mechanisms of refractory pain, as seen in our patient with a demyelinating disease. We propose that the effect of radioneuromodulation is an excellent mechanism for improving pain and quality of life. However, further clinical trials are needed.

Essential tremor (ET) is one of the most common adult movement disorders. As the worldwide population ages, the incidence and prevalence of ET is increasing.  Although most cases can be managed conservatively, there is a subset of ET that is refractory to medical management. By virtue of being “reversible”, deep brain stimulation (DBS) of the Ventral Intermediate Nucleus (VIM) of the thalamus is one commonly accepted intervention. As an alternative to invasive and expensive DBS, there has been a renaissance in treating ET with lesion-based approaches, spearheaded most recently by High-Intensity Focused Ultrasound (HIFU), the hallmark of which is that it is non-invasive. Meanwhile, stereotactic radiosurgical (SRS) lesioning of VIM represents another time-honored lesion-based non-invasive treatment of ET, which is especially well suited for those patients that cannot tolerate open neurosurgery and is now also getting a “second look”. While multiple SRS platforms have been and continue to be used to treat ET, there is little in the way of dosimetric comparison between different technologies. In this technical study, we compare the dosimetric profiles of three major radiosurgical platforms(Gamma Knife, CyberKnife Robotic Radiosurgery, and Zap-X Gyroscopic Radiosurgery (GRS) for the treatment of ET. Treatment plans were generated for all three platforms, utilizing a uniform sample patient. The respective treatment plans are shown in figures 1-3.  The volume receiving 5 Gy (V_5Gy), 10 Gy (V_10Gy), and 12 Gy (V_12Gy ) is reported as well as the gradient index (V50%/V100%), and V35% which is the volume receiving half of prescription dose. These parameters allow us to make uniform comparisons across the platform. These dosimetric parameters are summarized in table 1 with indication of collimator size and energy used. In general, GRS and Gamma Knife were shown to have the best dosimetric profiles for VIM lesioning, which is mainly the result of lower beam energy and smaller collimators that are utilized by these platforms. Nevertheless the relevance of such superiority to clinical outcomes requires future patient studies.

Introduction: Chronic, refractory orofacial pain, persistent, concomitant, continuous (PCC) pain in primary trigeminal neuralgia or derived from tumors, deafferentation pain from surgery, destructive or lesioning procedures such as radiofrequency, failed radiosurgery or usually a combination of various techniques, can have a devastating effect on patients and care givers. Radiosurgery to the medial structures of the thalamus has been used for oncological pain and non-oncological pain over the years, specially to the centromedian and parafascicular complex region. Radiomodulation effect can be understood as a substantial (more than 50%), quick pain response (hours to days) after treatment that cannot be explained by lesion formation due to the brief time span after treatment.

Methods: We present our experience in forty-six patients that have been treated with radiosurgery from Nov 2016 to Dec 2023 to the contralateral medial structures of the thalamus alone (10), in combination with the ipsilateral trigeminal nerve to the pain (34) and in two cases bilateral irradiation of the thalamus. Doses to the thalamus have varied from 90 to 140 Gy and 80 to 90 Gy to the nerve.

Results: Radiomodulation effect was noticed in 60% of those patients treated unilaterally with single target to the thalamus, overall success rate defined by visual analogue score of less than 50% and Barrow Neurological Institute BNI less than IIIb was 50% at last follow-up. In the 34 patients treated by dual strategy to the nerve and contralateral thalamus radiomodultaion effect was seen in 21 (62%) at last follow up 73% were improved. On the two patients with bilateral irradiation of the thalamus both experienced radiomudulatory effect, one remains pain free at one year and the other one has a 70% pain relief at 2 months. Facial numbness has been close to 30% for those treated to the nerve only. 

Conclusions: Radiosurgery of central structures of the thalamus has been proven to be a safe alternative to obtain pain relief in most refractory patients experiencing complex trigeminal pain and other orofacial pain.

Radiomodulation effect in pain is a phenomenon occurring at a timespan to brief to be explained by lesioning of the nerve or other central pain, pathway structures. It may be transitory in nature, with pain relapses that are usually better tolerated and less intense than the original pain. 

There is a need for more clinical trials and longer follow upto validate the success rate of radiosurgery in this subgroup of patients.

Breast cancer is the 5th cause of cancer-related mortality, with metastatic disease developing at the time of diagnosis in 20-30%, with leptomeningeal metastasis in only 5-8% of cases.

Objective: To describe a clinical case with multimodal and multidisciplinary management in a patient with HER-2 clinical stage 4 breast cancer, with liver and leptomeningeal metastases, using radiosurgery and intrathecal chemotherapy as part of the treatment.

Case report: A 53 year old female patient, upon self-examination detecting a mass in the right breast, went to a specialist who initiated an oncological study protocol, finding an additional tumor in the liver, confirmed by PET/CT. A radical and simple mastectomy were performed in the right and left breast, respectively, and histopathology confirmed HER-2/neu, positive 3+, p53 positive breast cancer. She was initially treated with chemotherapy with a regimen of Pertuzumab, Trastuzumab and Docetaxel, every 15 days for 7 months, and subsequently treated with Pertuzumab and trastuzumab every 15 days for 9 months and then TDM1 every 15 days to date.

The patient had stable breast and liver cancer disease during the first 20 months after the diagnosis. Then, she presented cerebellar syndrome, and leptomeningeal metastases were found by cranial MRI. Whole brain radiotherapy (WBRT) was used to treat these metastases. The patient's symptoms improved, and lesions were not observed by MRI 3 months after WBRT. 15 months later, the patient presented mild ataxia, and in the control brain MRI scan reactivation of the leptomeningeal disease was observed at the infratentorial level. At this point, a lumbar puncture was performed, with cerebrospinal fluid positive for neoplasic cells. An Ommaya catheter was fixed to deliver intrathecal treatment with Methotrexate/Dexamethasome/Trastuzumab. The patient improved, but required walking assistance. 12 months after catheter placement, the patient presented infratentorial reactivation of 5 solid lesions in the cerebellum and cerebellar vermis, which were then treated with radiosurgery. Systemic and intrathecal chemotherapy is still underway. 4 years after diagnosis, patient is currently stable, with moderate gait ataxia.

Conclusion: Although there is still no defined strategy for patients with leptomeningeal metastasis, in this patient, the treatment with radiosurgery, combined with systemic and intrathecal chemotherapy, has been beneficial in terms of quality of life and prolonged survival. Radiosurgery appears to be an effective treatment for solid lesions, offering tumor control and increased survival.

Stereoteactic radiosurgery was developed with the aim of providing non-invasive treatment in neurosurgical pathologies, including functional pathologies such as essential tremor and tremor associated with Parkinson's disease where the ventral intermediate nucleus of thalamus has been used as a target with proven success.

Although most treatments have been reported with gamma knife, radiosurgery with LINAC has also shown successful results.

Between March and April of this year at the Puebla Specialties Hospital of the IMSS, radiosurgical treatment was carried out on 5 patients with Parkinson's disease refractory to pharmacological medical treatment, all with different forms of presentation from spastic to kinetic.

The dose used of 75 to 85 Gy was given in a single session randomly, with monthly monitoring maintained until now. Although the initial period to assess the effects of radiosurgery treatment is 8 to 10 months, at 6 months we have observed an improvement of at least 60% in terms of control of involuntary movements of patients, likewise these benefits have been manifested in neurological tests such as UPDRS, Hoehn-Yahr and Scwarb-England.

In subsequent months, close monitoring will continue, waiting for greater improvement with the combination of pharmacological medical treatment and waiting for the average effect time of radiosurgery.

Background:

Endolymphatic sac tumors are a very rare type of tumors located in the petrous portion of the temporal bone. They can occur sporadically or be associated with Von Hippel-Lindau syndrome, causing symptoms depending on the structures invaded by the tumor. Typically, it presents with neurosensory hearing loss, vertigo, and facial paralysis. The standard management is surgical resection; however, due to the challenging location, complete resection is often difficult. Therefore, radiosurgery could be an option for local control and symptom remission.

Case:

This involves a 27-year-old male who, in 2019, experienced sudden-onset central vertigo, making ambulation impossible. Additionally, he had decreased hearing, prompting him to seek an ENT specialist who ordered a brain MRI. The MRI revealed a poorly defined tumor of the left endolymphatic sac measuring 27x18x26mm in its anteroposterior, lateral, and cranial-caudal axes, with extension towards the jugular vein. Given these findings, the patient underwent embolization and surgical resection.

Three months after the procedure, in March 2019, a follow-up simple and contrasted ear MRI showed a residual tumor adjacent to the jugular vein gulf, measuring approximately 8x10x8mm. The patient was then referred to our center to assess the residual tumor for radiosurgery.

In June 2020, simulation was performed using a simple and contrasted brain MRI and we contoured the residual tumor. A prescription of 16 Gy/1Fx was given to the 84% isodose curve using CyberKnife, with a treatment duration of 28 minutes.

Currently, the patient is under follow-up with simple and contrasted brain MRI, demonstraiting tumor stability.  The patient continues with daily activities without experiencing any symptoms.

In conclusion, based on this case report, the patient with this rare tumor benefited from a multidisciplinary approach. Given the challenge of achieving complete resection, receiving radiosurgery has yielded excellent results over a 3-year follow-up. Continued documentation of such cases is essential for a clearer understanding of treatment outcomes.

Introduction. Severe tremor can have a devastating impact on a patient’s quality of life. Deep brain stimulation (DBS) and radiofrequency thermocoagulation (RFT) are established therapeutic options for tremor reduction. In our clinic, we offer patients that are ineligible to these invasive surgical procedures Gamma Knife radiosurgery (GKRS) as a last resort option. Here we evaluate the clinical efficacy of these procedures and seek for ways to optimize GKRS.

Materials and methods. Data were retrospectively retrieved from patient records between 2013 and 2022 in a single center. Initial target for all procedures was the ventral intermediate nucleus of the thalamus. Patient-reported tremor outcome and satisfaction were conjointly classified on a 4-point Likert-scale. Adverse effects (AE) were recorded, including balance impairment, dysarthria, sensorimotor decline, infection, or hemorrhage with clinical deterioration. For all patients a Leksell frame was used for stereotaxy. DBS and RFT were performed awake to optimize targeting. For GKRS, a single 4 mm shot with a prescription dose of 130 Gy was used; planning was done on a T1-weighted MR image.

Results. 198 treatments were performed in 178 patients: 98 for GKRS, 62 for DBS and 38 for RFT. Most common diagnoses were essential tremor (n=98) and Parkinson’s disease (n=79). Mean age of the GKRS patients was significantly higher than for DBS and RFT (respectively 78 versus 67 and 69 years). Proportion of patients that was satisfied with their treatment outcome was highest for DBS (87%), followed by RFT (74%) and GKRS (52%). Incidence of AE was lowest in the GKRS group (1%). Dysarthria was more present in DBS patients, whereas sensorimotor impairments was more present in the RFT group.

Conclusion. GKRS treatment is a very safe and reasonably effective tremor treatment in selected patients, but is in our series still less effective than current invasive methods DBS and RFT. We acknowledge the obvious limitations of our current retrospective and qualitative approach. However, as DBS and RFT study results are in line with those of the literature, we think conclusions are valid. The lower GKRS treatment outcome may be explained by the fact that during DBS and RFT usually multiple targets are identified, frequently also in the subthalamic white matter, indicating significant interindividual variability. Recently, we incorporated new MRI techniques in our GKRS protocol to better visualize the hypothalamic region (FGATIR) and to image thalamodentate fibers. Further studies should assess whether this personalization can increase efficacy of GKRS for tremor.

Purpose

Ventricular tachycardia (VT) in patients with structural heart disease is associated with reduced quality of life and poor prognosis. Therapeutic options include medication, anti-tachycardia pacing or shock by implantable cardiac devices and catheter-based ablation of heart arrhythmogenic substrates. STereotactic Arrhythmia Radioablation (STAR) tested in a phase I/II trial by Robinson and colleagues offers a novel approach.

Materials and Methods

Dosimetric and clinical data from a retrospective series of 5 high-risk patients with VT refractory to catheter ablation and medication, treated with STAR are reported from a single referral center.

The clinical target volume (CTV) was defined to encompass the arrhythmogenic substrate by a team of a radiation oncologists and treating electrophysiologists, based on clinical and electro-anatomical information derived from CT scan and catheter ablation maps. An internal target volume (ITV) was added to CTV to compensate for heart and respiratory movement. The planning target volume (PTV) was then defined by adding an isotropic margin of 2-3 mm to the ITV.

Volumetric Modulated Arc Therapy (VMAT) plans were generated, optimized, and delivered using a TrueBeam^TM (Varian Medical System) linear accelerator employing both cone beam CT and surface-guided radiotherapy for real-time image guidance.

The prescription dose to the PTV was 25 Gy in 1 fraction.

Results

Mean CTV, ITV and PTV volumes, were 141.1cc, 187.7cc, 298.1cc, respectively. Mean heart volume was 1740.6 cc. The main dosimetric data are summarized in Table 1(A).

All 5 patients completed STAR procedure and treatment. There were no acute treatment-related adverse events. Clinical and treatment-efficacy data are summarized in Table 1(B). STAR significantly reduced or abrogated arrythmia at a median time of 24 weeks (range 4-48) post-treatment. Patient n.1 and n.3 showed a remarkable reduction of VT episodes at 4- and 8-weeks post-treatment, respectively. Patients n.2, n.4 and n.5 were free of VT episodes at 6-months post-treatment.

At a median follow-up time of 11 months (range 1-19), 2/5 patients are alive (patient n.2 and n.4), both free of VT events at 1-year post-treatment. Patient n.1 died due to complication after cardiac transplantation, patients n.3 due to sepsis and multiorgan failure and patient n.5 due to COVID pneumonia, at 11-, 1- and 5-months post-STAR, respectively.

Conclusion

These data suggest that LINAC-based STAR is a safe and effective treatment option in high-risk patients with VT refractory to catheter ablation and medication. Results from large prospective studies will define optimal patient selection and inform about long-term outcomes.

Background: One approach to treating medically refractory tremor is radiosurgical thalamotomy, which ablates aberrant cerebello-thalamo-cortical circuitry by targeting the dentato-rubro-thalamic tract (DRTT) within the ventral intermediate nucleus (VIM) of the thalamus We report on the accuracy and precision of frameless, MLC-based linear accelerator radiosurgery using a thermoplastic mask and optical surface imaging for intra-fraction motion monitoring.

Methods: 40 patients, diagnosed with either essential tremor or Parkinsonian tremor, underwent unilateral SRS thalamotomy on an Edge linear accelerator (Varian Medical Systems, Palo Alto, CA) on an IRB-approved clinical trial (ClinicalTrials.gov Identifier: NCT03305588). In each patient, the VIM was identified using stereotactic reference coordinates and automated scripting. Scripted treatment planning was done in Eclipse (Varian Medical Systems) with 1 mm dose calculation grid size on a treatment planning CT having 0.8 mm slice spacing. Patients were immobilized using the non-invasive Encompass SRS Immobilization system (CQ Medical, Avondale, PA). Treatment encompassed a single dose of 135Gy (Dmax) delivered using our previously described MLC-based 4.5mm-equivalent virtual cone technique. Patient position was monitored real-time using optical surface imaging with either AlignRT (VisionRT, London, UK) or IDENTIFY (Varian Medical Systems). 3D high-resolution (0.8 mm) T1-post Gadolinium-contrast MPRAGE imaging was obtained 3 and 6 months post-treatment on a 3T PRISMA MRI scanner (Siemens Healthineers, Erlangen, Germany) and was co-registered to the high-resolution pre-treatment T1 MPRAGE 3T image using a two-stage linear registration (rigid followed by affine). The enhancing lesion was segmented using a semi-automated, threshold-based method. The center-of-gravity (COG) of the lesion and the planned 50% isodose (67.5Gy virtual cone) volume were compared.

Results: At the time of analysis, post-treatment imaging data was available for 33/40 patients.  The analysis showed a mean 3D Euclidean distance of 0.9 mm between the centroids of the enhancing lesion and the 50% isodose volume. Detailed measurements of the X, Y, and Z offsets of the lesion centroids from the treatment isocenter were recorded (Figure 1), with their respective mean and standard deviation values: 0.2 ± 0.4, 0.5 ± 0.4, and 0.0 ± 0.7 mm for X, Y, and Z, respectively. 

Conclusion: Our findings indicate that frameless, mask-based linear-accelerator radiosurgical thalamotomy provides high-level accuracy and precision in lesioning the intended target within the thalamus. Our work demonstrates planning and delivery accuracy comparable to that reported for traditional frame-based radiosurgery.

Background: Trigeminal Autonomic Cephalalgias (TAC) are rare and so are studies pertaining to their surgical management. Cluster headache is the most common form of TAC. Gamma knife radiosurgery (GKRS) targeting the sphenopalatine ganglion and trigeminal nerve is sometimes used in medically refractory cases. The efficacy of such management remains debated, with only a few case series with conflicting results reported in the literature.

Objective: This study was designed to evaluate the efficacy of GKRS for the management of TAC. The specific goals were to assess the duration of pain relief, the recurrence rate, and the occurrence of adverse effects. 

Methods: We conducted a retrospective study of patients who underwent GKRS at our center for TAC between 2004 and 2022. The final cohort consisted of 20 unique patients (18 cluster headaches, 1 SUNCT, 1 SUNA), for whom a maximum dose of 80 Gy was administered on the ipsilateral sphenopalatine ganglion and/or trigeminal nerve. Six patients had repeat GKRS for pain recurrence. Baseline demographics, symptoms and pain characteristics were collected prior to treatment. Symptoms and pain evolution as well as complications were obtained at follow-up. Outcomes were analyzed using the Kaplan-Meier method and descriptive statistics.

Results: For cluster headache patients, primary treatment yielded adequate pain control (mBNI IIIb or better) in 79% of cases. The median time to pain relief was 4 months with pain control lasting a median of 27 months. Pain recurred in 80% of patients who had initial relief. Retreatment yielded pain control in 83% of cases, with a median time to pain relief of 3 months and median pain control lasting 7 months. Pain recurred in 40% of cases after repeat GKRS. New bothersome facial numbness (BNI III or worse) at last follow-up occurred in 11% after primary treatment and in 50% of repeat procedures.

Conclusion: Gamma knife radiosurgery targeting the trigeminal nerve and/or sphenopalatine ganglion appears to be a reasonable procedure to achieve pain control in patients with cluster headaches. Although pain relief was temporary in most cases, retreatment can be used but at the cost of higher occurrence of bothersome facial numbness. This is, to our knowledge, the largest single center case series reported on this topic.

Introduction

Trigeminal neuralgia (TN) is a chronic, episodic, and disabling facial pain syndrome that negatively impacts patients quality of life. The initial treatment is pharmacological; if this fails, there are invasive alternatives. Radiosurgery is a non-invasive treatment with low toxicity and good results that can be considered as the first line of treatment. The purpose of the study is to present our results obtained when treating this pathology through radiosurgery with Gamma Knife, safety and efficacy.

material and methods

Since November 2022 with the start up of our Gamma Knife (GKS) unit, 26 patients with TN have been treated, the data was collected prospectively and evaluated retrospectively. Assessing the frequency and intensity of pain, as well as trigeminal function before and after GKS on a regular basis. 61.5% of the treated patients were women and 38.5% men, with a mean age of 57.5 years (25-84), mean duration of symptoms 82.8 months, BNI Scale IIIb, IV and V pretreatment in 13% , 73.9% and 13% respectively, maxillary and mandibular branches of the trigeminal nerve are the most affected. Previous treatments in 62.5% of cases, microvascular decompression in 8/26 patients, thermoablation in 15/26, infiltrations with botox in 2/26 patients and only one case Previous radiosurgery.

Results

After one year of follow-up, 50% of patients have adequate pain control with an average recovery time of 3 months. 76.2% of the patients did not present any complications derived from Radiosurgery, 3 of the cases presented some mild neurological deficit such as local paresthesia, there were no grade 3 and 4 toxicities. In all cases, treatment was carried out with a dose of coverage of 63 Gy at 70% coverage isodose, with maximum point dose of 90 Gy.

 Conclusion:

In our series the follow-up is short, however half of the patients presented a significant improvement in pain. Gamma Knife radiosurgery is an effective treatment for trigeminal neuralgia; in our series, patients with previous treatment combinations of decompressive microsurgery and thermocoagulation presented worse results. Typical pain appears to be a good predictor of pain relief.

The current standard of care treatment for patients with ≥15 brain metastases (BM) is whole brain radiation therapy (WBRT), despite poor neurocognitive outcomes. A 37-year old male with metastatic lung adenocarcinoma (PD-L1 5%, EGFR exon 19 deletion) initially presented with a seizure and numerous intracranial metastases and previously completed a course of WBRT to a total dose of 3000 cGy in 10 fractions at an outside hospital. He subsequently started first-line oral Osimertinib therapy, with baseline PET/CT showing multiple sites of disease.

After 18 months from initial diagnosis and WBRT, the patient presented with 94 new brain metastases while on maintenance Osimertinib (Figure 1A). He had a Karnofsky performance score of 90, no neurological deficits, and only occasional headaches. His baseline cognitive objective Patient-Reported Outcome Measurement Information System (PROMIS) score was 29/40.

Given his age, failure of EGFR-targeted therapy, and prior WBRT, he was planned for single-isocenter multiple target (SIMT) fractionated SRS to all lesions to a total dose of 2400 cGy in 3 fractions to 91 lesions and 1800 cGy to 3 brainstem metastases. He was simulated with a Qfix© Encompass mask (Qfix, Avondale, PA, USA) and treated on a Varian Edge linear accelerator utilizing HyperArc (Varian, Palo Alto, CA, USA), a 6DOF robotic couch with daily CBCT, and a Varian Optical Surface Monitoring System. A planning target volume (PTV) was created using 2 mm margin around the GTV, with a smaller margin of 1 mm for the brainstem metastases. Total GTV was 8.6 cc and PTV was 40.1 cc (Figure 2).

He tolerated SRS well with no acute side-effects. Due to progressive systemic disease he transitioned to atezolizumab, paclitaxel, carboplatin, and bevacizumab combination therapy. Follow-up MRI imaging at 2 and 5 months were consistent with post-treatment changes with no increase in volume or number of brain metastases (Figure 1B). His serial PROMIS scores were 29, 29 and 26 at 3, 6 and 9 months of follow-up respectively. At last follow-up, 11 months after SRS, he remained free of headaches or new neurological symptoms. Due to systemic progression of disease, he transitioned to comfort care 30 months after BM diagnosis and 11 months after SRS. This case illustrates one of the largest number of metastases treated in a single course of SRS, and this treatment was well tolerated with no significant cognitive decline, with a comparable survival outcome to contemporary studies evaluating WBRT in this population.

INTRODUCTION

Only 55-89% of ventricular tachycardias (VT) are resolved nowadays with current treatments (antiarrhythmic drugs (AAD), endocardial ablation), and up to 50% recur before 2 years. Recently, non-invasive stereotactic cardiac radioablation (SABR) is beginning to be used in the scenario of these refractory patients with promising initial results. The precise delimitation of the arrhythmogenic substrate makes it possible to limit the adverse effects on the healthy myocardium, the risk organs and the implantable automatic defibrillators (ICD), and all of this requires the coordinated work of a multidisciplinary team.

AIM

To describe the experience in our center treating the first case of SABR in Andalusia, performed in a patient with ventricular tachycardia originating from an apical aneurysm of the left ventricle (LV) refractory to AAD and multiple endocardial ablations.

MATERIAL AND METHODS

A 58-year-old male patient with a 10-year history of ischemic dilated cardiomyopathy and extensive LV apical aneurysm with severe left ventricular dysfunction (LVD) and ICD-CRT implantation. Episodes of VT and multiple ICD shocks refractory to AAD and four endocardial ablations of the arrhythmogenic focus located in the LV apical aneurysm (2016, 2010, 2020, last in July 2021) with partial success. In August 2021 there is an arrhythmic storm (3 or more discharges in 24 hours) that cannot be controlled with FAA. Finally, it was decided to perform cardiac SABR. A single dose of 25 Gy was administered on September 17, 2021, over a clinical volume defined in 4D planning CT with respiratory gating, after fusion with cardiac CT with intravenous contrast in cardiac cavities, using VMAT-type IMRT guided by TAC-Symetry. (IGRT) using 3 arcs and 332 segments, in Elekta VERSA linear accelerator.

RESULTS

Tolerance was excellent, with only grade 1 nausea at 48 hours, resolved with supportive treatment.

With a 2-year follow-up, the patient has only had two new episodes of VT with a different morphology from those previously recorded, which is compatible with its origin in another location, not in the arrhythmogenic substrate that was irradiated, and they both were resolved with an ICD discharge.

A great impact has been confirmed in the improvement of his quality of life, without worsening of his functional class and with echocardiographic controls without pericardial effusion, myocarditis or worsening of LVEF.

With this treatment, a new therapeutic option opens up for patients with VT refractory to drugs or endocardial ablations.

Objectives: Recurrent or resistant pain is a well know occurrence following surgical and radiosurgical treatments for Trigeminal Neuralgia. We reported pain control and complications in a large serie of patients undergoing frameless LINAC radiosurgery retreatment as long as safety and efficacy of retreatments are poorly known.

Methods: The protocol for the first treatment aims to deliver an homogeneous radiation dose to an extended segment (6 mm) of the trigeminal nerve. Retreatments are performed on patients resistant to treatment (no pain improvement within 6 months) or with temporary clinical benefit and subsequent recurrent pain. A lower dose is typically prescribed for the second treatment to reduce the risk of sensory complications. Pain control and sensory complications (facial numbness) are assessed using the dedicated BNI scales.

Results: 93 patients underwent retreatment for resistant or recurrent trigeminal pain were included. Mean age was 61,3 years (range 29-89). Mean interval between first and second treatment was 24.2 months (range 4-136 monts). 15 patients (16.1%) were retreated within six months for resistant pain. 25 patients (26.9%) were retreated within 12 months while 53 patients (57%) were retreated for recurrent pain at later time (12 to 136 months). Three patients required a third treatment. Mean dose delivered at the first treatment was 58.5 Gy (range: 30-75 Gy), prescribed to a mean 82.6% isodose (range 77-89). Mean dose delivered at the second treatment was 45.3 Gy (range: 30-63 Gy), prescribed to a mean 83.2% isodose (range:79-89). Mean volume at the first treatment was 28.8 mm³ (range: 9-55) while 25.1mm³ (range: 8-44.4) at the second. One year after the second treatment satisfactory pain control was achieved in 85 out of 93 patients (91.4%) and remained stable after 3 and 5 years. Sensory complications appeared in 27 patients out of 93 (29.3%) after 1 year and showed a mild improvement over the following years. Somewhat bothersome facial numbeness (BNI grade III) was found in 18 retreated patients (19.4%) while very bothersome facial numbess (BNI grade IV) developed in 3 patients (3.2%). No other neurological complication was found.

Conclusions: Radiosurgical retreatments for resistant or recurrent trigeminal pain are safe and effective and provide a high rate of long-term pain control. This comes at the price of a higher rate of sensory complications. Further studies are needed to confirm these results and assess wheter the rate of sensory complications can be reduced while preserving long-term pain control.

Objective: To identify imaging correlates of response and complications using FLAIR MRI and DTI in patients undergoing Gamma Knife Thalamotomy for Essential Tremor.

Patients and Methods: Forty four patients underwent Gamma Knife Thalamotomy for Essential tremor between 2001 and 2022 and had at least 12 months of follow up. Imaging follow-up was performed with MRI in 27 patients, CT in 1 patient and included Diffusion tensor imaging in 4 patients.

Results: Overall clinical response with tremor reduction and was seen in 85% of patients with complications in 3 patients. Complications were motor weakness and incoordination. Lesion accuracy was 100% in all imaged patients. FLAIR signal changes exceeding 5 mm in diameter on MRI at the thalamotomy site were associated with clinical response. Additional flair change in the posterior limb of the internal capsule was observed in 40% of patients. Extensive capsular flair change involving the genu and more anterior parts of the internal capsule and/or flair changes in the cerebral peduncle and insular cortex with or without sylvian fissure deformation were associated with clinical evidence of motor deficits. Diffusion Tensor Imaging (DTI) analysis showed significant reduction in the volume of ipsilateral Dentato-rubral tract fibers after successful radiosurgical lesioning and was associated with good tremor response. Decussating fibers were inconstantly affected. Once interrupted fiber tracts were not seen to reappear and tremor response was durable. Complications were associated with treatment related edema in three cases and with an unrelated adjacent cavernoma bleed in one patient. Expectant and corticosteroid management was used in all cases and recovery was near complete in all cases in terms of motor function except for the patient with hemorrhage who remained weak on the contralateral side.

Conclusions: MRI FLAIR can successfully predict both response and complications in patients following Gamma Knife Thalamotomy. DTI tractography shows significant reduction in fibers of the ipsilateral Dentato-rubro-thalamic tract in patients with response to lesioning.

Objective

Relatively, stereotactic radiosurgery has not been indicated frequently for skull metastasis. Although some experiences has been reported, most of them were skull base metastasis. We investigated the clinical outcomes of Gamma knife radiosurgery (GKRS) for skull metastasis.   

Patients & Methods

In our hospital, the metastatic brain tumors occurring in the skull accounted for a very low proportion. Four patients who underwent GKRS radiosurgery for metastatic skull tumors over the past 5 years were reviewed. All of them had metastatic brain tumors, and GKRS was performed to both brain and skull metastases.

The mean age was 71.3 (range 53 to 81). The primary cancers were lung (n=2), renal cell cancer (n=1) and cervical cancer (n=1). The tumor volume was 1.14 cc (range 0.36-2.62 cc) on average. Median prescription dose was 15 Gy (range 12–16 Gy) with 50% prescription isodose. The average coverage and selectivity of shots were 0.99 (range 0.98–1.0) and 0.70 (range 0.55-0.91).

Results

We obtained clinical and MRI follow-up data for three patients. No acute or late radiation-induced skin complications in the patients. Two of them were controlled, and the progression free survival was 3-months and 6-months, respectively. The other patient showed progression 3 months after GKRS. 

Conclusions

GKRS for skull metastasis, even for skull vault metastasis, might be performed at the time of GKRS procedure for brain metastasis, simultaneously.

Background

CBCT based image guidance for cranial stereotactic radiotherapy treatments is standard practice.  The isocentre verification is based on matching bony anatomy. Soft tissue changes are not usually visualised. We report a case where in the patient had developed a bleed which was noted on the CBCT leading to changes in practice as well as expanding the knowledge of radiation therapists.

Clinical Case

A 43-year old man presented for a further course of fractionated stereotactic radiotherapy (FSRT) for multiple brain metastases from an undifferentiated basal cell adenocarcinoma of the salivary gland, confirmed on histology. The patient was scheduled to have FSRT to a dose of 25-30Gy. The CBCTs for the first two fractions had showed a hyperdense area outside of the target volume of one of the lesions and the radiation therapist requested a review by the treating radiation oncologist. It was confirmed to be a tumour-related bleed on the repeat planning MRI. Two other lesions had grown slightly but were within the targets. A re-plan was done for the remaining three fractions with the patient and family made aware of the reasons behind the change.

Discussion

Soft tissue details on CBCT are difficult to visualize due to the inherent sub-optimal image quality. Haemorrhagic intracranial metastasis can occur in 3-14% of presentations¹. A non-contrast CT scan is the imaging of choice in diagnostic radiology to detect bleeds and the appearances may vary². These distinctions are difficult to ascertain on CBCT.  This patient was flagged after two fractions had been delivered rather than prior to treatment. This potentially reflects the lack of good quality imaging as well as awareness of changes seen due to bleeding which can happen within brain metastases.

Following this incident, we updated our departmental image guidance policies and also included this as part of ongoing education of the radiation therapists and are exploring the possibility to improve the quality of CBCT.

Conclusion

CBCTs are useful in detecting intracranial haemorrhage within metastases and this should be part of the educational component of radiation therapists to become a specialist or an advanced practitioner in cranial stereotactic radiotherapy.

References

1.   Gaillard F, Rasuli B, Bickle I, et al. Haemorrhagic intracranial metastases. Reference article, Radiopaedia.org (Accessed on 31 Dec 2023) https://doi.org/10.53347/rID-1421

2.  Macellari F, Paciaroni M, Agnelli G, Caso V. Neuroimaging in intracerebral hemorrhage. Stroke. 2014 Mar;45(3):903-8. doi: 10.1161/STROKEAHA.113.003701. Epub 2014 Jan 14. PMID: 24425128. (Accessed on 1 Jan 2024) https://pubmed.ncbi.nlm.nih.gov/24425128/

Introduction: Central Nervous System Lymphoma (CNSL), either primary (p) or secondary (s), is an aggressive and often fatal disease. Stereotactic Radiosurgery (SRS) is utilized as a minimally invasive strategy for relapsed/refractory (r/r) pCNSL/sCNSL, offering efficacy while reducing risk of leukoencephalopathy, especially in cases that Whole-Brain Radiation Therapy (WBRT) is avoided. This retrospective study investigates the outcomes of r/r pCNSL/sCNSL patients treated with SRS over a 15-year period in an NCI-designated Comprehensive Cancer Center. We aimed to assess volumetric response, progression-free survival (PFS), overall survival (OS), and identify prognostic factors. 

Methods: Patients with CNSL diagnosis between 9/2005-6/2022 who were treated with brain SRS were identified. Utilizing GammaPlan, contrasted brain MRIs at regular post-SRS intervals were analyzed to measure residual tumor volumes. Leukoencephalopathy grades were determined by a dedicated neuro-radiologist. Kaplan-Meier analyses, Log-rank tests, and Cox regression models were employed for survival assessments. 

Results: A cohort of 29 patients with median age of 70, underwent SRS for treatment of 44 relapsed or refractory tumors. Best volumetric response (≥90% volume reduction) was achieved within 3 months for 70.5% of the tumors. In-field CNS progression was observed in only 2 tumors and WBRT was avoided in 72.4% of patients, with a median time to WBRT of 6.5 months. Post-SRS FLAIR changes were generally mild (grade 0: 65.5%, grade 2: 24.1%, grade 3: 3.4%). Multivariate analysis identified a longer interval between CNS disease diagnosis and SRS, lower Karnofsky Performance Status (KPS), older age at CNS diagnosis, and increased post-RT FLAIR changes as factors correlating with worse OS. On the other hand, higher recursive partitioning analysis (RPA) score, lower KPS, and increased FLAIR changes were associated with worse CNS progression-free survival.

Discussion: Stereotactic radiosurgery emerges as a safe and effective treatment modality for relapsed/refractory CNS lymphoma. Delay in SRS post CNSL diagnosis, poor functional status and older age are among poor prognostic factors in patients with CNS lymphoma.

Introduction

Parkinson's disease is characterized by the presence of motor symptoms. There are multiple treatment options. The purpose of this paper is to report on the workflow and outcome of a patient with Parkinson's disease tremor treated with linear accelerator radiosurgery (SRS).

Methods and Materials

A 70-year-old patient with Parkinsonian tremor of the right upper limb. On the Fahn Tolosa Marin (FTM) tremor scale, the global score was 53 and the Subjective overall assessment was 75%. functional radiosurgery was chosen, delivering a dose of 140Gy at Dmax. High resolution MRI images were obtained and to identify specific brain structures and regions. The patient was immobilized using an SRS thermoplastic mask. The initial isocenter was located in the VIM of the left thalamus by indirect coordinates (AC-PC) and the final isocenter was defined taking into consideration the position of the left DRT fiber and left internal capsule. The linear accelerator was a TrueBeam STx with 4mm conical cone. A dose of 140Gy was delivered to the isocenter.The treatment was performed on February 24th, 2022 and the total treatment time was 75 minutes. 

Clinical and imaging follow-up

The patient was monitored one month after treatment, showing a slight improvement in tremor. At 4 months post-treatment, the patient presents a marked improvement, on the FTM scale he obtained a value of 31 (previous 53) and a subjective global assessment of 25%. An MRI was performed, evidencing in T1 images with gadolinium a tenuous hypointense lesion of 2 mm with a hyperintense halo that together measure 5.2mm whose center coincides with the treatment isocenter. At 8 months post-treatment, Brain MRI was performed where the lesion of the same size was observed but with a marked increase in its hypo- and hyperintensity. At 16 months, complete improvement was observed, with no action tremor. A neurological evaluation was carried out with the FTM scale with a value of 11 (previous 53) and a subjective global evaluation of 0% (previous 75%). A control MRI was performed, observing the lesion of the same size and characteristics

Conclusion 

As this case report is showing,  it is feasible to create focused lesions isolated to the region of interest within the thalamus using LINAC-based SRS. The evolution of this patient showed a remarkable clinical response at 16 months after treatment with a  correlation between  the VIM and the target.

Biological Effective Dose (BED) oriented planning has emerged as a potential strategy in the future provision of personalised Stereotactic Radiosurgery (SRS) treatment plans. Since it is well known that dose rate plays an important role in the tissue response, the status of the sources at the time of treatment should be considered as much as the factors related to the patient for individualised treatment plans.

To identify potential factors that may influence the outcomes, 191 idiopathic, type 1 trigeminal neuralgia (TN) patients who had undergone SRS as a first-line invasive treatment were investigated. All treatment plans targeted the trigeminal nerve in the prepontine cistern with 40 Gy to the 50% isodose. Follow-up data were obtained from the patient records retrospectively.

The median follow-up was 46 months (range: 12 – 266), 90.1% of patients (n = 172) experienced pain relief following treatment. Of those, 172 patients, 51.2% (n = 88), had relapse during their follow-up. Kaplan-Meier analysis showed the median relapse-free duration was 73 months with an estimated 32.1% relapse-free status at 10 years. Medication status information was available for 186 patients and 38.7% (n = 72) were able to come off their medication. An additional 36.6% (n = 68) were on a reduced dose at the end of their follow-up.

Univariate Cox Regression analysis showed that as the shot distance from the root entry zone (REZ) increases by each millimetre, the hazard ratio (HR) for relapse increases by 16.3% (95% CI 2.4% - 32.2%) (p = 0.020) and for every 10% increase in the BED the REZ receives, the HR reduces by 4% (95% CI 1.4% – 6.4%) (p = 0.003). Univariate logistic regression analysis showed that for every millimetre the shot was positioned more distally, the odds of being medication-free at the end of the follow-up reduced by 21.5% (95% CI 2% - 37.2%) (p = 0.032). On the other hand, multivariate logistic regression analysis showed that the maximum BED applied to the nerve was a positive predictor for causing new numbness (p = 0.046), when corrected for pain duration before SRS (p = 0.016), plugging (p = 0.960) and age at treatment (p = 0.053).

These results indicate that increased BED to the REZ, gives better pain control. Maximum BED applied to the nerve relates to the risk of facial numbness, which is generally well tolerated, even when all patients were treated with the same maximum physical dose. 

Background: We present the clinical application of non-invasive stereotaxic radioablation of ventricular tachycardia (VT) refractory to medical and surgical treatment.

Objective: The patient suffered an acute myocardial infarction, during the period of hospitalization, balloon angioplasty of the right coronary artery was performed. In 2007, VT paroxysm developed for the first time with a tachycardia cycle duration of 400-410 ms, which was stopped by electropulse therapy. In 2010, RFA of VT was performed in the area of the periscar zone with a positive effect. The right coronary artery is a previously implanted stent without signs of significant restenosis or thrombosis. In 2018, RFA of the ectopic focus (posterior septal region of the left ventricle ) was performed with a positive result. In 2020, relapse of VT with a heart rate of 140 beats/min. In 2020, RFA of VT (the area of the lateral wall of the left ventricle) and implantation of a two-chamber ICD with a remote monitoring function were performed. Since June 2021, the resumption of VT paroxysms up to 1-5 per week, stopped by the ICD algorithm.

 Material and methods: Based on the results of invasive navigational activation mapping, a pericicatrical zone in the interventricular septum associated with VT was verified. Radiosurgical irradiation of the target in the region of the interventricular septum and the posterior apical segment of the left ventricle was performed on a TrueBeam STx in accordance with the segmental scheme of the left ventricle. Irradiation doses for 95% of the internal target volume (ITV, 17 cm³) and planned target volume (PTV, 46 cm³) (31.2 and 25 Gy, respectively) were delivered by two full coplanar arches in 1 session. Irradiation was performed during expiration using a respiratory control system. The loading dose to critical structures was within tolerance. The planned follow-up period is 18 months. According to remote monitoring, the intensity of VT paroxysms over 48 days after treatment was from daily to 2-3 per day. 

Results: Then, the incidence of VT paroxysms decreased (1-3 per week), and from the 64th to the 450 th day no VT paroxysms were recorded, which suggests that the impact was highly precise, conformal, and involved the total wall thickness. No undesirable effects and damage to adjacent organs were observed.

Conclusion: The technique of stereotactic radioablation of VT refractory to traditional treatment has shown effectiveness and safety, which can be considered as an alternative treatment method for patients with VT.

INTRODUCTION/AIM

Lung Stereotactic body radiotherapy (SBRT) is a very well stablished radiotherapy option for metastatic disease and early-stage lung cancer. The safety and side effects have been carefully analyzed. It needs to be considered: location (central vs. peripheric), DVH´s organ at risk (OAR), 4DCT for motion analysis, etc., are crucial. Lower lobe (LLL) lesions are one of the most challenges due to the width range of head and foot movement that includes diaphragm, unfortunately it isn’t consider any constraint for this structure. This study aimed to analyzed 3 clinical cases with the same characteristic and a common late side effect: diaphragm´s fibrosis.

MATERIAL / METHODS

This study investigated from a local series (2015-2022) with 51 patients (p.)., 21 lung lesions, only 3 clinical cases were in LLL, close to diaphragm, treated with SBRT total dose 60Gy/5 fractions, treated on LINAC (Novalis Tx), IGRT with ConeBeam CT. The study's primary outcome was to analyze late toxicity profile and local control rate.

RESULTS

Three patients were treated with LLL- SBRT. The mean age was 43 years old (24-59), 3 women, mean size lesion 55cc. (17-120cc.). The primary tumor: 1p. sarcoma, 1p. cervical, 1p. pancreas. Local response rates were: complete response 2p., progression 1p. The overall survival rate was 64 months (45-87), mean time local control 27 m. (2-59). Acute toxicity was grade 3 pneumonitis 1p., 2p. grade 2 cough. Late toxicity was observed in 3 p. painful lung fibrosis lesion, with radiological pneumonitis not SUV uptaken greater than 2. Management was: 1p. was surgically resected and pain disappeared, second p. during surgery bleeding tumor was observed and died due to postoperative complications, the last one is under control with pregabalin.

CONCLUSION

There are a lot of published data related to potential late side effects on lung SBRT, we need to also consider new OAR: as diaphragm, to increase not only local control, also quality of life of our patients. After theses clinical case´s analysis, we need to consider big volume LLL lesions at higher risk of develop painful diaphragm fibrosis. Adequate supportive management: analgesic or surgery could be a solution.

Aims: To assess the feasibility of Stereotactic Body Radiotherapy (SBRT) using the Elekta 1.5T MRI linear accelerator (MR-Linac) for the treatment of kidney metastasis in 2 patients with oligometastatic lung carcinoma.

Methods: Between August 2022 and June 2023, 2 patients with isolated clinical/radiological local progression in the kidney, confirmed by biopsy and FDG PET-CT, received SBRT. The age of patients was 64 and 60 year-old. The first patient was initially treated by the immuno-chemotherapy with carboplatin-pemetrexed-pembrolizumab, followed by pembrolizumab maintenance. The second patient had a first line EGFR-targeted therapy by osimertinib, and at the time of progression a new endobronchial ultrasound biopsy showed a small cell neuroendocrine carcinoma transformation, treated by carboplatin-etoposide. Due to persistent right kidney metastasis, as confirmed by biopsy and after institutional Tumorboard decision, SBRT directed to the isolated kidney metastasis using the MR-Linac was offered. Dosimetric goals respecting organ at risk dose constraints  were achieved. The SBRT plan was computed with the Monaco treatment planning system. We reported dosimetric parameters and toxicity according to CTCAE v 5.0 at 14 months after SBRT completion for patient 1 and acute toxicity for patient 2.

Results: A total dose of 40 Gy was delivered in 5 fractions to the isolated kidney metastasis volume in  both patients. Four-dimensional CT scanning was used for treatment planning to account for respiratory motion. Treatment was delivered using the MR-Linac with daily dosimetric readaptation based on daily MRI imaging and real-time MRI motion monitoring. Neither  patient experienced acute gastrointestinal (GI) or genitourinary (GU) toxicity. At 14 months post-SBRT, patient 1 did not experience chronic GI or GU toxicity. Renal function, as assessed by estimated glomerular filtration rate (eGFR) and serum creatinine level, remained unchanged after SBRT.

Conclusion: While other local treatments such as cryoablation (CA) or radiofrequency ablation (RFA) exist, SBRT, particularly when using the MR-Linac, is an emerging noninvasive option that provides high-precision radiotherapy requiring few outpatient visits. It represents a safe and effective management option for isolated renal metastasis.

INTRODUCTION:

Liver cancer is the sixth most common cause worldwide, accounting for four percent of cancer related deaths in India. The 5 year survival rate of HCC is only about 18%. This is mostly attributable to the fact that more than half of HCC patients are diagnosed at an advanced stage, with widespread lesions in the liver, moderate to severe ascites, vascular invasion and thrombosis and /or metastases.

SBRT in the presence of gross ascites is a challenging situation due to both physiological and technical aspects. Here we present the procedural details of this commonly encountered complex situation.

METHODS AND MATERIALS:

We present a case of 74 year old non smoker, non-alcoholic gentlemen with ECOG score 1 , who was evaluated for loss of appetite and weight for 2 months.

 After complete laboratory and radiological workup patient was diagnosed with HCC and bland thrombus in the extra-hepatic main portal vein along with moderate ascites and portal hypertension. After multi-disciplinary tumor board discussion, patient was planned for SBRT to the primary and the portal vein thrombus with DIBH technique followed by lenvatinib as further line of management.

Baseline Child Pugh score was assessed and a pig tail catheter was placed to manage the ascites and thereby to help us avoid undue abdominal movemet. Prevention taken for the risk of hepato-renal syndrome and peritonitis as the chances increase with pig-tail insertion. Immobiliasation and CT simulation was done with the help of DIBH technique after assessing the patients baseline lung capacity. The bland thrombus was contoured; GTV to CTV margin of 3mm given; CTV-PTV margin 5mm was given. SBRT dose of 40Gy in 5 fraction given; with dose per fraction of 8Gy with BED of 72Gy, α/β ratio of 10 for the tumor thrombus. Residual liver volume being >700 cm3.

Everyday laboratory parameters were monitored particularly for serum albumin and creatinine. Input and output charts are monitored. On the treatment couch patient was setup using ABC machine and everyday treatment was done using DIBH technique. Inter-fraction translational and rotational errors were corrected

CONLUSION:

SBRT in HCC with gross ascites is not uncommon. however, the procedure requires vigilance as there is a chance of radiotherapy treatment error or detoriation in the patient’s general condition due to infection or derangement of liver parameters. The above mentioned procedure can act as a guide during treatment so as to improve the treatment quality without any untoward effects.

Introduction

Spinal metastases have an incidence of 16%, of which 2/3rd are from breast, prostate and lung. 

PET CT and MRI-guided SBRT is safe and effective, especially in oligometastases/oligo recurrence , even in reirradiation, however  it  is challenging due to spinal cord tolerance and potential radiation induced myelopathy. 

Here, we present a case of HRPC with recurrent and progressive bone metastases post  reirradiation to spine  with symptomatic radiation myelitis, treated with mesenchymal stem cell infusion.

A 52 year  gentleman from Africa  diagnosed with High risk Adenocarcinoma prostate in 2011 underwent HT, Brachytherapy and IMRT. He progressed on hormonal therapy  within an year and developed  metastases in D7 vertebra for which he underwent SBRT to a dose of 17Gy/1#(elsewhere) and started on Apalutamide. He visited our center with progression with multiple bone metastases  in January 2014. He was treated with SBRT to D5, D7, D9 vertebrae and was started on Inj. cabazitaxel, but again he had disease progression. Case was re-discussed in MDT, Since patient  refused further chemotherapy, considering good local response post RT,  he was again treated with SBRT to dose of 30 Gy in 5 fractions to  D3, D4,D5  D7. Of these, D5 received SBRT thrice, with a gap of 3 years and 10 months in between. He presented in May-2018 with right foot-drop and sensory deficit in left leg.  PETCT showed progressive disease. MRI spine showed myelitis at the level of D5 and was refractory to conventional treatment with high dose steroids. So, two sessions of Mesenchymal stem cell therapy was planned as a last resort. Mesenchymal stem cell transfusion (Systemic and intrathecal) was done in December 2018 after which the patient had symptomatic relief. However, he succumbed to progressive disease in June 2020.

Re irradiation with SBRT to vertebrae is challenging  due to proximity of the spinal cord. It should be considered after weighing the potential benefit and risks with respect to spinal cord tolerance, time interval between the radiation, life expectancy, Quality of life of and feasibility of systemic therapy. However, in the rare possibility of an event like myelitis, newer options like mesenchymal stem cell infusion or low dose bevacizumab may yield a  possible benefit. 

Background: Adjuvant breast radiotherapy practice standard is 40 Gray in 15 fractions. 40 patients, from November 2020 to December 2023, with early breast cancer were treated after primary surgery, with ultra-hypofractionated 5 fractions in one week schedule WBI regimen of 26 Gray (Gy), based on the FAST FORWARD trial results, and 0,6Gy/fraction of simultaneous integrated boost (SIB) for a total dose of 29Gy/5,8Gy delivered in 5 fractions. This study attempts to identify the safety, low toxicity profile and patient convenience compared to other hypofractionated schemes.

Methods: 40 cases of patients, aged 40-70 with invasive carcinoma of the breast T1–2, pN0, M0 who underwent radiotherapy after breast conservation surgery are presented. Concurrent trastuzumab and/or endocrine therapies were allowed. For patient participation, all the inclusion criteria of the FAST FORWARD trial were met. 26 Gy in five fractions to the whole breast, with SIB of 29Gy to the tumor bed over one week, was delivered. At the breast conservation surgery, two pairs of titanium clips were implanted into the walls of the tumour excision cavity (tumor bed) to assist target delineation. Planning Target Volumes PTV_wb and PTV_TB were created by adding a 3d uniform expansion of 10mm to the CTV_wb and 5mm to the CTV_boost containing the tumour bed (clips), respectively. For dose-volume histogram assessment, lungs, heart, contralateral breast, and ipsilateral ribs were contoured. VMAT treatment plans using 6MV beams were used for the patient treatment. Daily pretreatment imaging verification was performed (CBCT), and all corrections were applied (6dCouch). Ultrasound examination and photographs were taken as baseline before the treatment. Follow-up assessment performed in week 1, week 4 and then every 3 months.

Results: All patients completed the 5 fractions schedule. The titanium clips proved to be necessary for the accuracy of the tumor bed delineation. The prescription dose was uniformly delivered to the whole breast and the tumor bed (V95%(PD)>95%). All dose constraints for OARs described by Fast-Forward trial were met. Follow up from 2 years to 6 months, no changes in breast appearance or shape were observed, while the skin reaction was grade 2 or less.

Conclusions: WBI regimen of 26 Gy in 5fx with SIB is a well-tolerated and safe hypofractionated radiotherapy scheme. It is also time efficient as it reduces the overall treatment time of EBRT to 1 week, with no differences in normal tissue toxicity or changes in breast appearance versus other radiotherapy schemes. 

Background

The UK PACE trials confirm the value of 5 fraction SBRT for men with prostate cancer who would otherwise have been treated with moderate or conventionally fractionated external beam radiotherapy. The PACE-B study has reported no significant difference in the acute GU and GI toxicity from 36.25Gy in 5 fractions of SBRT vs 62Gy in 20 fractions.

Materials and Methods

The use of the RayPilot system with HypoCath tumor tracking in this study has the potential to reduce acute toxicity,  using a Linac-based system, permitting an urethra sparing approach. The modified Foley Catheter based HypoCath system with an implanted transmitter can easily identify the prostatic urethra which may allow a relative dose reduction to this structure reducing GU toxicity and deliver continuous tumor tracking with reduced margins around the prostate, and lower dose to surrounding tissues and the rectum.

Results

Five patients (PSA<_10ngr/ml, Adenocarcinoma Gleason Score <_7ngr/ml, T2N0MO, IPSSscore<12) underwent SBRT (prostate+- proximal SV) from Aug. 2022 – December 2023) 5fractions/7,25Gy per fr/36,25Gy, using the RayPilot system. First the RayPilot Foley transmitter catheter was insert into the patients bladder prior to the CTsim. Rectal suppository administered pre scan to evacuate rectum. Bladder drained of urine and 100 ml of water instilled into the bladder before CT sim. 1.25mm pelvis CT slices were acquired and RayPilot Foley catheter was removed after the CT sim scan. CTV = prostate minus the urethral PRV. The CTV to PTV margin = CTV plus 3 mm except posteriorly where the prostate abuts the rectum, where a 2 mm margin will be applied. 6MV FFF VMAT. Organs at Risk OAR’s (Rectum, bladder, penile bulb, urethra, femoral heads, bowel) were contoured. During treatment, RayPilot system with HypoCath transmitter was insert to patient. Observation intrafraction tracking was set to 2mm deviation tolerance. A Pre-treatment daily CBCT acquired to check bladder and rectal filling. Tumor intrafraction tracking and beam interruption was applied if prostate moves outside of 2mm tolerance. To restart the treatment a new CBCT was applied to verify patient position after fraction interruption. Median dose delivery time per fraction was 10 min. Early follow-up with a median of 6 months, no SBRT-related GU or GI side effects occurred. The HypoCath system was well patient tolerated.

Conclusions

Our initial experience shows that prostate SBRT using intrafraction RayPilot system with HypoCath tumor is safe and well tolerated minimizing GU side effects permitting an urethra sparing approach.

This presentation aims to demonstrate benefit and unique edge of Adaptive Magnetic Resonance (MR)-Guided Stereotactic Ablative Radiotherapy (SABR) in patients that may require multiple re-irradiations to adjacent targets. Use of small margins on 0.35T MR Linac, based on online target tracking; beam gating; better MR image quality on delineating anatomy of the day, aids adherence to cumulative organs at risk (OARs) dose, thus reducing toxicity in a setting of multiple re-irradiations.  

In November 2021, a male patient in his early 60s with metastatic gastroesophageal adenocarcinoma was referred for an adaptive MR-guided SABR radiotherapy to a solitary right adrenal met, adjacent to liver and inferior vena cava, at GenesisCare Cromwell, in London. Previous treatments involved, 4 cycles of FLOT; followed by open two phase oesophagogastrectomy with extended two field lymph node dissection; and laparoscopic transabdominal left adrenalectomy for metastatic disease. A 40Gy in 3 fractions adaptive MR-guided SABR treatment to the right adrenal met was completed early December 2021.

Diagnostic images that were taken in the 1^st half of 2022 detected multiple metastatic para-aortic disease. GI endoscopy showed no evidence of infiltration. Chemotherapy with Nivolumab, Capecitabine, Oxaliplatin on a three-week cycle commenced in July 2022. A 15^th of September 2022 PET-CT scan demonstrated complete response in all nodal sites. However, a November 2022 PET/CT scan showed progression in aortocaval node at the level of L2/L3. Patient was referred for 40Gy in 5 fractions adaptive MR-guided SABR treatment to the metastatic aortocaval node given the proximity to the bowel and previous SABR to the right adrenal gland. A recovery of 25% was applied to nearby OARs on calculating the remaining dose tolerances. Treatment was completed in January 2023.

A 27^th of February 2023 PET/CT scan showed almost complete response at the aortocaval node. However, a 2^nd of May 2023 PET/CT scan demonstrated progression of a 1.6cm left para-aortic node at L2/L3 disc level. Just cranial to this level, was a treated aortocaval node that showed reduction in size from 14mm short axis in November 2022 to 9mm in February 2023 and 8mm in May 2023 with no convincing metabolic activity. Patient was referred for adaptive MR-guided 30Gy in 5 fractions SABR to the left para-aortic node. In as much as only 10% cumulative recovery was applied to nearby OARs, it was possible to come up with a very decent plan, V100% of 88.53%.

All 3 SABR plans adapted very well onset.    

Background: Surgery is the primary treatment for early-stage lung cancer. Patients with medically inoperable lung carcinomas or patients that refuse to undergo surgery are treated with definite Radiotherapy. Stereotactic ablative radiotherapy (SABR) is a compelling non-invasive therapeutic modality for this group of patients, that confers promising results.

Patients and Methods: We retrospectively analyzed 27 patients with medically inoperable early-stage lung cancer that underwent SABR in our institution. SABR was delivered via the Cyberknife M6 robotic radiosurgery system.

Results: There were no acute or late toxicities from the skin or the connective tissue of the thorax. Grade 1 radiologically documented lung injury occurred in 58.3% of patients, while localized grade 2 and 3 toxicities of non-clinical significance were observed in 12.5% and 8.3% of cases, respectively. In a subsequent radiobiological analysis, a trend towards higher incidence of grade 2 and 3 lung toxicity was noted when a higher equivalent dose delivered in 2Gy fractions (EQD2) was prescribed (p=0.18). Local control (LC) was achieved in 100% of patient at the time of the first follow-up and the projected 18-month local progression-free survival (LPFS) was 94.7%. The projected 18-month disease-specific overall survival (OS) and progression-free survival (PFS) was 93.3% and 82.9%, respectively.

Conclusion: High LC, PFS and OS rated can be achieved with SABR for early-stage lung cancer, with minimal toxicity. The study continues to recruit patients to obtain mature results in the following years.

BACKGROUND: The aim of this study was to report the efficacy and toxicity of salvage stereotactic body radiation therapy (SBRT) for local prostate cancer recurrence after radiotherapy in a single isocenter.

MATERIALS AND METHODS: The study group consisted of 26 patients with locally recurrent prostate cancer after radiotherapy or after prostatectomy and radiotherapy, treated with SBRT between 1.01.2021 and 13.12.2023 in Franciszek Lukaszczyk Memorial Oncology Center in Bydgoszcz. The mean age was 71 (55-80). The reccurence was intraprostatic in 18 (69%), in seminal vesicles in 6 (23%), in tumor bed in 2 (8%) patients. One patient had reccurences in prostate and seminal vesicle and 3 patients had synchoronus metastates to pelvic lymph nodes.  All patients were treated with focal SBRT with 3 different schedules: 30 Gy in 3 or 5 fractions every day and 35 Gy in 5 fractions given every other day. The statistical analysis was performed using Statistica ver 13.3software

RESULTS: Median follow up was 17,3 months. During this time one patient had a local progression and 5 patients developed regional or distant metastases without local progression. Two patients had serious side effects (rectal bleeding and urinary retention) both in the 30 Gy in 5 fraction regimen.

CONCLUSIONS: Stereotactic body radiation therapy  is a safe and effective treatment metod for patients with local prostate cancer recurrence after radiotherapy.  Irradiation with a total dose of 35Gy in 5 fractions given every other day is a preffered schedule.

Background: The geriatric population, which has been steadily growing for several decades, poses a significant therapeutic challenge. The aim of our study is to compare the management of localized lung cancers by stereotactic radiotherapy (SBRT) and thoracic surgery in terms of efficacy and tolerance in patients aged over 80.

Methods : In our retrospective single-center study, we analyzed two cohorts of patients aged 80 or older with localized lung cancer (stages I-IIB), treated from January 2012 to November 2021 at Bordeaux University Hospital using either surgery or stereotactic radiotherapy (SBRT). The primary endpoint was 3-year overall survival (OS). Secondary endpoints included 3-year progression-free survival (PFS), rates of local, lymph node and metastatic relapse, and treatment toxicity.

Findings : A total of 139 patients were included, with 35 undergoing surgery and 104 receiving stereotactic radiotherapy (SBRT) between January 2012 and November 2021. The median age was 83 years. In the SBRT cohort, 88.5% of patients were excluded from surgery due to cardiovascular or respiratory comorbidities, while the remaining 11.5% declined surgery outright. There were significant differences between the two groups in terms of general condition (WHO), Charlson comorbidity index, chronic obstructive pulmonary disease and forced expiratory volume in first second (FEV1). OS at 3 years was 68.8% in the SBRT group versus 74.1% in the surgery group. 3-year PFS was 65.2% after SBRT versus 72.6% after surgery. Local and metastatic relapse rates were 3.8% and 10.6% respectively in the SBRT group and 6.1% and 15.2% after surgery. No lymph node relapse was observed in the surgery group versus 8.6% in the SBRT group. Surgery facilitated nodal upstaging in 25.7% of cases. Postoperative complications occurred in 54.3% of patients, including 22.9% grade III to V. Two toxic deaths occurred within 3 months of surgery. In the SBRT group, 26.7% of patients experienced toxicity, of which only 2% were grade III, with no cases of grade IV or V.

Interpretation : For patients aged over 80 with stage I-II lung cancer, overall survival at 3 years appears to be superior after surgery compared with SBRT. However, this observation needs to be nuanced by the higher prevalence of comorbidities in patients treated with SBRT. Nevertheless, local and distant control rates are comparable. The decision-making process between these two techniques could benefit from more precise refinement through systematic dedicated oncogeriatric consultation and assessment of post-treatment quality of life.

Background

Plasmacytoma, a rare plasma cell disorder, often presents as solitary or multiple tumors within the bone marrow or soft tissues, typically associated with multiple myeloma. Extramedullary plasmacytomas (EMP), particularly located in the external auditory canal (EAC), are exceedingly rare and pose significant treatment challenges due to their location, anatomical complexity, and high risk of recurrence.

Observations

We report a case of a 72-year-old man with a history of multiple myeloma, presenting with recurrent left EAC plasmacytoma. Following initial conventional radiotherapy for the lesion, a recurrence occurred in seven years. The patient subsequently underwent stereotactic radiosurgery, which proved successful, leading to complete resolution of the lesion without any long-term adverse effects or irradiation-related complications over a 45-month period. 

Lessons

This case is a unique instance of utilizing stereotactic radiosurgery for recurrent EMP in the EAC, highlighting its potential as an effective approach in managing complex plasmacytomas.

Aim

To evaluate the effectiveness and tolerance of treatment with ultrahypofractionated radiotherapy (FAST-Forward scheme) in our centre.

Material and methods

Between March 2017 and October 2022, 173 patients were treated in the Radiation Oncology service of the Virgen de las Nieves Hospital using extreme hypofractionated radiotherapy. The mean age was 58.7 (41-92) years. 13% of the patients were early stages, 82.9% were locally advanced and 4.1% were metastatic. Surgery was conservative in the majority of cases (81.1%), and mastectomy was performed in 18.9%. Integrated boost was performed in 47%. In 63.4%, irradiation of lymph node levels I-II was performed, in 7.2% of levels I-IV, in 2% of levels III-IV, and only in 1 patient was the internal mammary chain included. In all cases, a total dose of 26 Gy to 5.2 Gy per fraction was used, and 29 Gy to 5.8 Gy as an integrated boost in selected cases. The toxicity of the treatment was evaluated according to the CTCAE v5.0 scale.

Results

The median follow-up of the patients was 28 months (3-67). Tolerance was very good in terms of acute toxicity, presenting grade 1 radiodermitis in the form of erythema in 37.7% and hyperpigmentation in 21.3%. Only 5 patients presented grade 2 moist radiodermitis and 7 cases of grade 1-2 esophagitis were detected. Late residual toxicity was detected in 27% of patients and grade 1 fibrosis in 38%.

Conclusions

In our centre, the acute and chronic toxicity figures are consistent with those presented in the phase III study in 2020. Treatment in the adjuvant setting with extreme hypofractionated radiotherapy is safe and well tolerated both after conservative surgery and after mastectomy, included in cases in which lymph node irradiation and a boost to the surgical bed are necessary.

Purpose/Objective(s) : SBRT is widely used for the treatment of early stage lung tumors with local control rates over 90% at 2 years. The tumor motion during respiration can be managed with the internal target volume (ITV) concept using a 4D-CT, gating techniques or deep-inspiration breath hold (DIBH) techniques. The DIBH techniques used to rely on spirometer devices coupled with visual patient feedback that needed a heavy workflows. The surface guidance offered by the ExacTrac Dynamic (ETD) allows an easy monitoring of the DIBH. We assessed the accuracy and reproducibility of surface guided DIBH lung SBRT using the ETD by analyzing the interfraction table shifts and clinical outcomes of the first consecutive patients treated in our center.

Materials/Methods: After patient setup in free breathing, a CBCT was performed during DIBH and table shifts were applied after the radiation oncologist review. Then, the patient performs a second DIBH for the treatment to be delivered with surface monitoring. Table shift values were collected for all directions and fractions and the duration of the treatment session was recorded. Patients were followed-up every 3 month with CT-scanner.

Results : Fifteen patients with 21 lung tumors were treated with SBRT (153 fractions) between 05/30/2022 and 12/06/2023 using the surface gated DIBH protocol. Mean and median fraction duration were respectively 13:28 (SD 06:08) and 11:56 (min 05:39 ; max 47:07). Mean absolute and median (min ; max) table shift values were respectively : vertical 0.21 cm (SD 0.26) and -0.02 cm (-0.86 ; 2.11), cranio-caudal 0.41 cm (SD 0.46) and 0.11 cm (-1.84 ; 1.93), lateral 0.24 cm (0.23) and -0.01 cm (-1.48; 1.12), pitch 1.24° (SD 1.0) and 0.2° (-2.8 ; 4.5), roll 0.76° (SD 0.76) and 0° (-4.5 ; 4.6), yaw 0.86° (0.77) and 0° (-2.9 ; 3). Thirteen patients (19 lesions) had at least 3 months imaging follow-up available. With a median follow-up of 11.6 months, local control was 90.5% with two in-field progressions, in the same patient treated for 3 metastases of colic cancer. Fourteen lesions (67%) had a complete radiological response. All post-SBRT lung radiological changes occurred within the PTV area. There was no grade > 1 toxicity.

Conclusion : Surface gated lung SBRT during DIBH for selected patients is feasible and reproducible. Preliminary clinical outcomes show great accuracy with high local control rates without evidence of geographical miss of the target with 5 mm margin PTV.

Objectives

The study aimed to comprehensively present data on treatment optimization in linac-based SBRT for localized prostate cancer at a single institution. Moreover, the dosimetric quality and treatment efficiency of single-arc (SA) versus dual-arc (DA) VMAT planning and delivery approach were compared.

Methods

Twenty low to intermediate-risk (36.25 Gy in 5 fractions) and twenty high-risk (42.7 Gy in 7 fractions) prostate SBRT plans delivered during 2021 with dual-arc FFF VMAT technique, were re-optimized by two medical physicists. The same PTV margin expansion (5mm/3mm posterior) was used. A single-arc approach was adopted and new optimization parameters based on the increased planning and clinical experience were incorporated in a new template. Dosimetric parameters of SA plans were evaluated and compared with the original DA plans, including target coverage, organs at risk (OARs) sparing, treatment delivery time, and accuracy (gamma analysis-passing ratio, PR). Paired t-test was used to assess the statistical significance level (alpha=0.05). One senior radiation oncologist performed a blind choice between DA and SA plans for clinical assessment.  

Results

In all cases, the SA optimization technique resulted in a better treatment plan than the original one. PTV D95% and D2% were comparable between the two techniques (SA: 96.7% and 104.1%; DA: 96.5% and 103.9%; P>0.05). A significantly increased OARs sparing was observed in SA plans, especially in rectum and bladder mean doses. The mean absolute dose difference was -3.7 Gy [-7.6 – -0.6] for rectum Dmean (P<0.001) and -1.2 Gy [-4.0 – 0.4] for bladder Dmean (P<0.001). The mean SA treatment delivery time was reduced by 22%, passing from 2.1 minutes [1.7 – 3.0] to 1.5 minutes [1.3 – 1.9] on average (P<0.001). The mean monitor units rose from 1819 ± 332 to 1967 ± 301 (P<0.001) due to higher plan complexity. Despite the increased fluence modulation, dose measurements reported an optimal agreement with dose calculations with PR greater than 95% for 2%(local)-2 mm criteria.

Conclusion

SA planning technique, with newly optimized parameters, achieved clinically equivalent target coverage while significantly reducing the dose to rectum and bladder compared to DA plans. The treatment delivery time was substantially reduced, lowering the probability of prostate motion beyond margins. These findings indicate a potential decrease in treatment-related toxicity and an improvement in actual target coverage during prostate SBRT treatments. Further investigations are warranted to assess the long-term outcomes associated with this planning technique.

Objectives:

To report the implementation of urethra-sparing linac-based Single-Dose Ablative Radiation Therapy (SDART) for unfavorable localized PCa with real-time intrafraction organ motion management (NCT04831983).

Methods:

From June2021 to July2023, thirty patients with localized unfavorable-intermediate or selected high-risk prostate tumors were enrolled to receive 24Gy SDART (BED1.5 = 408Gy). Patients were simulated with empty rectum and bladder filled by catheter. Fused CT and T2W 3D MRI image sets were used to delineate target and OARs. PTV consisted of CTV with 2-mm isotropic margin. A high-dose avoidance zone (HDAZ) was created by a 3-mm expansion around rectum, bladder, and urethra. Plans were optimized using 10MV-FFF single arc with minimum target dose defined by the OARs constraints and dose escalation to 24Gy to the volume away from HDAZ. During the treatment delivery, CBCT matching ensured accurate patient setup and an electromagnetic device allowed for real-time prostate motion monitoring. Treatment was interrupted and position was corrected when the prostate exceeded a 2-mm threshold. Acute toxicity was evaluated with CTCAEv5 3 months post-treatment.

Results:

All planning objectives were achieved (Table 1). Median CTV and PTV were 50.8 cc [16.3–75.7] and 72.0 cc [25.6–100.6], respectively. The average total monitor units per plan were 6910±592. All the treatment plans fulfilled a 2%/2mm gamma passing rate >95% objective using a 2D silicon diode array. The mean delivery time lasted 4.3±0.5 minutes [3.3–5.7]. The overall mean treatment time, from procedure inception to beam-off, was 15.9±8.4 minutes [6.9–35.5]. Intrafraction tracking was successfully carried out in all sessions and beam interruptions due to target motion beyond limits were needed in 17 patients (57%), with 1.5 [1–2] interruptions per patient on average. The prostate was found within 2-mm from its initial position in 82% of the treatment time, i.e. in 77% of the time during the setup phase and in 93% during the delivery phase (beam on + interruptions). At 3-month follow-up, only one patient experienced GI side effects (G1), while GU toxicity was observed in eight patients (six G1 and two G2), mainly consisting of increased urgency and frequency.

Conclusions:

Our preliminary findings offer encouraging perspectives on the safety of 24Gy SDART. The use of negative dose-painting during planning and online tracking during delivery to limit the volume of rectal mucosa receiving critical doses and to accomplish intra-prostatic urethra sparing is feasible. Long-term results are awaited to confirm the efficacy of single fraction in the treatment of localized PCa.

Purpose/Objective

Some special radiotherapy techniques use planning computed tomography (CT) scans taken in breath-hold.

Here we focused on expiration breath-hold (EBH) CT. Exhalation level on EBH CT should correspond to normal expiration. CT scans are usually taken using voice instructions, typically (CT default):  „Breathe in, breathe all the way out and hold your breath.“

In this work we wanted to verify the assumption that the expiration on EBH CT would be greater than the normal expiration from 4DCT because the patient expire more after the mentioned voice instruction.

Material/Methods

Sixty-five patients who were treated with lung SBRT were included in this study. Patients were coached to perform normal expiration when instructed for EBH CT followed by a 4DCT.

The range of motion of the external marker is in the order of millimeters, therefore, it was necessary to assess differences in the internal anatomy of the patient. We compared the position of the diaphragm copula on the planning EBH CT and the expiratory phase of secondary 4DCT.

Breathing waveforms acquired during the CT scan using an external marker on the patient's body were analyzed to assess whether the patient responded to the voice instruction and to visualize the breathing waveform.

After analyzing the patient data, we proceeded to modify the voice instruction as follows: „Breathe normally and hold your breath when you are ready to exhale“. This approach requires monitoring the breathing curve by the operator or by gating technology. In this first phase of this work, we tested its effect on three healthy volunteers. Recordings of breathing curves comparing the default and the new voice instruction were acquired.

Results

The assumption was not confirmed in any patient. 5 patients out of 65 were excluded due to the presence of artifacts on 4DCT in the diaphragm region. Surprisingly, 40 (67%) out of 60 patients showed a larger exhalation on 4DCT than on EBH. In such cases, the mean difference between expirium on EBH CT and 4DCT was 8,3±4,5 mm and 8,0±4,7 mm for the right and left diaphragm copula respectively. In the remaining 20 cases, the difference was less than 1mm.

Analysis of the breathing curves showed that default voice instruction causes less expirium after inspirium by changing the baseline of breathing pattern for for the next few breaths. The use of  the new voice instruction resulted in smaller change in baseline and better breathing curve stability in volunteers.

Introduction: Stereotactic body radiation therapy (SBRT) is the preferred treatment for medically inoperable early-stage non-small cell lung cancer (NSCLC) and lung metastasis. Several studies aim to understand the interaction between high-dose radiation, tumor, and normal tissue response. Post treatment changes typically include fibrosis of the lesion and surrounding normal lung tissue. Our institution previously reported that 10.70 Gy in 5 fractions was a threshold for pulmonary fibrotic change in our patients. This study aims to assess normal tissue lung fibrosis post-SBRT, quantifying pulmonary fibrotic volume and verifying dose parameters for fibrosis in normal lung tissue.

Methods: Patients treated between January 2020 and December 2021 were reviewed. We combined data from the radiation treatment planning platform with the data culled from our institutional electronic medical record. Extracted data include PTV, lung fibrotic tissue volume, lung volume receiving 20Gy, Max dose at 2cm, and time to fibrotic tissue development. Descriptive statistics will compare fibrotic volumes to PTV for each treatment and dose distribution in the fibrotic region.

Results: Nineteen patients were evaluated with a 24-month follow-up revealing fibrotic tissue formation. 17/19 had COPD/Asthma/Pulmonary Hypertension at diagnosis. 10/19 developed fibrotic tissue outside the PTV field. Mean lung fibrotic tissue volume was 24.41 cm3.  Bilateral lungs received 20 Gy at a mean volume of 4.36% .  The mean max dose at 2 cm: 2672.03 centi-gray (cGy).  Mean PTV Volume was 42.95 cm3.  Minimum lung dose was 4410.38 cGy, maximum lung dose was 5803.4 cGy.  Anatomical locations included 6 right upper lobe, 8 left upper lobe, 3 right lower lobe, and 2 left lower lobe lesions.  Histopathologic diagnoses included 13/19 with non-small cell lung carcinoma, and 3/19 patients with metastatic disease.

Discussion: We present preliminary evaluation of 19 patients treated with lung SBRT focusing on normal lung tissue changes after treatment.   Half of our patients treated with SBRT developed pulmonary fibrotic change outside the PTV volume, and a significant number of these patients had pre-existing co-morbid pulmonary illnesses.   We plan to expand our evaluation to the entire patient cohort, with the hope of determining the clinical significance of these changes in an already compromised patient population. 

During stereotactic body radiation therapy, image guidance supported by surface guidance allows for precise patient setup and motion management while reducing patient’s exposure to ionizing radiation. Using optical cameras, a real-time map of the patient's body is created, and a region of this map is used as  a surrogate for the lesion. By tracking the surrogate using optical cameras, the position of the target is inferred, therefore reducing the need for additional ionizing radiation imaging. However, the optimal skin region choice for a surrogate is not always clear. In this study, we used four-dimensional computed tomography (4DCT) images of 58 patients acquired for the purposes of treatment planning in our institution to provide information of both skin and lung respiratory motion. The analysis of nine skin surrogates and a bifurcation of a blood vessel in the lower right lung lobe delineated as a target structure has been conducted using an in-house developed computer program. Respiratory excursions of skin surrogates and lung target structure have been measured, and Pearson’s correlations between the surrogates and target structure respiratory motion have been computed generating amplitude and correlation maps of the patient's skin. Differences in both amplitudes and correlations to target structure motion between skin surrogates have been detected with regions of skin without rib cage support having significantly better correlation to target structure motion, as well as larger amplitudes. The magnitudes of these differences vary between the patients, indicating that an individualized approach should be considered when choosing skin surrogates for lower lung lesion motion management.