A 39yo male patient with recurrent and progressive epidermoid tumor mass in the left temporomesial area presents to the outpatient department with nightly structural epilepsy resulting in daytime drowsiness and fatigue. The patients as whether LITT could be performed to help him stop his seizures. The patient was operated at the age of 25 on his histologically proven epidermoid via a retrosigmoid approach to decompress the cerebellopontine angle and the brainstem. At the age of 36 he was operated via a frontotemporal transsylvian approach, after which he received proton-radiotherapy with a cumulative dose of 52.2Gy. His temporomesial tumor mass is slightly progressive and he is impacted by his nightly seizures with temporal origin as per EEG. The patient is not willing to undergo another open respective surgery. Stereotactic planning was performed and the temporomesial tumor mass would be amenable to a 10mm laser fiber ablation with multiple pullbacks. Main question: - Would an epidermoid tumor mass respond well to LITT? There are no reports on using LITT in the literature.

Patients with neurofibromatosis frequently suffer from complex, mixed chronic pain that is often refractory to conventional pharmacological and surgical interventions. When the quality of life is severely compromised, stereotactic functional neurosurgery offers a palliative alternative. We present a case of bilateral anterior cingulotomy (BAC) performed via MR-guided Laser Induced Interstitial Thermotherapy (MRgLITT). A 59-year-old female with multi-complicated NF2 and a 20-year history of refractory pain (VAS 8/10) was selected for BAC. The procedure was performed under robotic assistance using real-time MR-monitoring to ensure precise laser ablation of the anterior cingulate gyrus while preserving the corpus callosum and adjacent vascular structures. The procedure was executed without technical difficulty. Immediate post-operative recovery was marked by a transient confusion syndrome lasting 48 hours, which is typical for this procedure. At the one-month follow-up, the patient demonstrated a significant reduction in pain perception and a dramatic improvement in autonomy. Clinical observations noted a decrease in analgesic demand, the disappearance of facial pain-related tension, and a successful return to assisted mobilization (standing and transfers). MRgLITT bilateral anterior cingulotomy is a precise, minimally invasive, and effective procedure for managing the affective-evaluative component of refractory chronic pain in complex genetic syndromes like NF2. Real-time MRI monitoring enhances safety by allowing immediate verification of the lesion size and location, significantly improving the quality of life for patients in therapeutic stalemate.

Objective: This work aims to comprehensively review the scientific rationale and existing evidence for combining Laser Interstitial Thermal Therapy (LITT) with Tumor Treating Fields (TTFields) in the treatment of glioblastoma (GBM), evaluating this multimodal strategy as a potential, logical advancement in neuro-oncology. Methods: A detailed analysis was conducted based on existing pre-clinical data, published mechanistic studies, and publicly available clinical trial protocols. The review methodically examines: 1) The individual mechanisms of LITT (coagulative necrosis, transient blood-brain barrier disruption) and TTFields (mitotic spindle disruption), 2) Hypothesized synergistic interactions, and 3) Practical considerations and research gaps identified in existing study designs. The OPTIMUS PRIME trial protocol was reviewed as a key framework for testing this combination. Results: The analysis confirms a strong complementary biological rationale. LITT provides immediate, localized tumor control and may condition the tumor microenvironment, potentially enhancing subsequent therapies. TTFields offers a non-invasive, sustained anti-mitotic effect targeting residual infiltrating cells post-ablation. The review of the OPTIMUS PRIME trial protocol identifies key parameters like treatment timing, while existing evidence points towards a potential for improved local control and progression-free survival compared to monotherapies. Conclusion: The combination of LITT and TTFields is a scientifically well-founded and promising treatment strategy for GBM. It addresses both macroscopic and microscopic disease through distinct, non-overlapping mechanisms. While prospective clinical validation is ongoing—as in the OPTIMUS PRIME trial—the review of existing evidence strongly supports its consideration as a potentially important therapeutic option that merits prioritization in clinical research for challenging glioblastoma cases.

Introduction: Recurrent high-grade glioma require innovative locoregional and systemic treatment options. Laser Interstitial Thermal therapy (LITT) is a stereotactic, minimally invasive surgical approach to target small and difficult to resect tumors under MR-thermometric guidance. Tumororganoids (TOs) are representative tumor avatars that enable ex-vivo drug testing even from small tissue samples provided by stereotactic biopsies. The Hi-SMILE study is a trial to evaluate safety and efficacy of LITT and feasibility of preclinical tumororganoid-based drug screening in n=30 patients with recurrent high-grade glioma. Material and Methods: Patients were prospectively enrolled in a registry. Fot LITT tumor volume and ablation coverage, as well as accuracy of laser catheter placement were assessed. OR time, length of hospital stay and surgical complications are documented. Stereotactic biospsy and laser catheter placement are performed before laser ablation is carried out in an intraoperative MRI setting. Biopsy samples taken during LITT surgery are partially used for TO formation. After TO formation, ex-vivo high-throughput drug testing of up to 9 selected drugs is performed. Responses are classified as „sensitive“ „intermediate“ or „resistant“. Results: n=30 patients (16 females, 14 males; mean age 58.9 years (+/- 9.98years) have been enrolled. Final histological diagnoses was glioblastoma (n=24), astrocytoma WHO 4° (n=4) and radiation necrosis (n=2). N=12 patients required 2 laser catheters to cover the desired mean tumor volume of 4.5 (+/- 4.8) ml. Mean operative time was 157minutes (+/- 48) of which a mean 89 minutes (+/- 30) were spent in the intraoperative MRI scanner. Ablation coverage was on average 202% and took on average 14min 19s per catheter. Laser catheters could be placed with a Euclidian distance of 0.9 mm (+/- 0.7) and a mean radial error of 0.7 mm (+/- 0.6). Treatment-related complications were three epileptic seizures and three deteriorations of a preexisting neurological deficit. It was possible to test for sensitivity of a median of 5 drugs. Most tumors revealed a high level of drug resistance with only 2 cases revealing drug sensitivity more than 1 drug. Conclusions: Surgical accuracy an ablation coverage was high. LITT is a safe and well-tolerated procedure. Progression free and overall survival need to be evaluated at the end of the follow-up. TO-based drug screening is feasible with tissue from stereotactic biopsies.

Background: Thalamic glioblastoma carries a dismal prognosis. Complete surgical resection is rarely achievable due to the eloquent deep-seated location. Laser interstitial thermal therapy (LITT) offers a minimally invasive alternative enabling rapid recovery and early adjuvant treatment initiation. Evidence on long-term outcomes following LITT in large thalamic glioblastomas remains scarce. Methods: We report the long-term follow-up of a 57-year-old woman presenting with a rapidly progressive right thalamic glioblastoma (IDH-wildtype, MGMT-promoter methylation 61%). At the time of surgery, the lesion had grown to 4.0 × 2.4 × 2.5 cm (13.1 cm³), exceeding standard LITT size recommendations. A trajectory traversing the Sylvian fissure was selected to maximize complete ablation. Three sequential ablations along a single trajectory were performed using the Visualase system under real-time MRI guidance. The patient showed no new neurological deficits following surgery. Adjuvant lomustine/temozolomide chemotherapy was initiated three days post-operatively, followed by concomitant radiotherapy (30 × 2 Gy) according to the CeTeG/NOA-09 protocol. Results: Complete macroscopic ablation was achieved without perioperative complications. However, the patient developed therapy-associated myelodysplastic syndrome following completion of the CeTeG protocol and subsequently underwent allogeneic stem cell transplantation. She remained progression-free from 2022 until 2026. In March 2026, a new superficial right parietal lesion was identified and surgically resected, with histopathology confirming recurrent glioblastoma. Stupp protocol (temozolomide with concurrent radiotherapy) has been initiated. Discussion: This represents an exceptionally prolonged progression-free interval for thalamic glioblastoma managed with LITT. This case underscores the potential benefit of aggressive trajectory planning to achieve complete ablation, combined with very early multimodal adjuvant therapy exploiting putative blood-brain barrier opening. A distant cortical recurrence pattern after nearly four years is noteworthy and may reflect both the efficacy of local disease control and the infiltrative nature of glioblastoma.

Background Ultra-early recurrence of glioblastoma (GBM), occurring between initial surgery and the start of concomitant radiochemotherapy has recently been associated with a median overall survival of 13.3 months in patients with such early recurrence, compared to 24.4 months in patients without recurrence in this interval. Currently, no standardized therapeutic strategy exists for this high-risk subgroup. Objective To evaluate the feasibility and safety of a novel treatment protocol that integrates laser interstitial thermal therapy (LITT) into the treatment algorithm for patients with ultra-early GBM recurrence prior to initiation of standard radiochemotherapy. Methods We are currently conducting a prospective, single-arm phase I feasibility study on 12 patients with radiologically confirmed ultra-early GBM recurrence detected on planning MRI prior to the start of concomitant radiochemotherapy. The study protocol integrates LITT between planning MRI and initiation of radiochemotherapy according to the Stupp protocol, aiming to achieve maximal local cytoreduction of contrast enhancing tumor without delaying standard-of-care treatment. Primary endpoints include feasibility, defined by successful completion of LITT without postponement of radiochemotherapy, and procedural safety. Secondary endpoints include progression-free survival, overall survival, and treatment-related morbidity. Results Recruitment is ongoing. Preliminary data suggest that integration of LITT into the pre-radiochemotherapy interval is technically feasible within a narrow therapeutic window. Detailed safety and timing analyses will be investigated. Conclusion Ultra-early GBM recurrence identifies a subgroup of patients with markedly impaired survival and unmet therapeutic needs. The present feasibility study explores a novel treatment protocol by incorporating LITT prior to standard radiochemotherapy. Upon completion of this phase I study, we plan to initiate a multicenter, randomized phase II trial to compare this approach against standard management. Recruitment of collaborating LITT centers will commence shortly.

Objective The limited efficacy of immune checkpoint inhibitors (ICI) in malignant brain tumors such as glioblastoma necessitates strategies to remodel the immunosuppressive tumor microenvironment (TME). This review aims to evaluate the preclinical and clinical rationale and synergistic potential of combining laser interstitial thermal therapy (LITT) with ICI. We hypothesize that LITT acts as an in situ vaccine and primes the TME for enhanced ICI response. Methods We conducted a systematic synthesis of current evidence from preclinical models, early-phase clinical trials (Phase I/II), and mechanistic studies. The analysis focused on LITT's immunomodulatory mechanisms—induction of immunogenic cell death (ICD) and transient blood-brain barrier (BBB) disruption—and their interaction with ICI (PD-1/PD-L1 blockade). Clinical data from ongoing trials (e.g., NCT02311582, NCT03277638) were incorporated. Results LITT triggers ICD, releasing tumor antigens and damage-associated molecular patterns (DAMPs), thereby initiating a tumor-specific adaptive immune response. Clinically, this leads to increased CD8+ T-cell infiltration and upregulated PD-L1 expression in the TME (Chandar et al., 2023). Concurrently, LITT induces a temporary, localized BBB opening, facilitating the entry of ICIs and immune cells. Early clinical trials (e.g., NCT02311582) of LITT combined with pembrolizumab in recurrent glioblastoma show promising long-term survival (4/9 patients ≥30 months) with a favorable safety profile. Conclusion The combination of LITT and ICI represents a promising multimodal strategy. LITT converts immunologically "cold" tumors into "hot" ones by remodeling the TME and transiently opening the BBB. ICIs then synergistically amplify and sustain this immune response. Early clinical data support this approach; however, optimal sequencing, biomarker development, and definitive Phase III trials are required to confirm therapeutic benefit and improve survival for patients with malignant brain tumors.

Background: Laser interstitial thermal therapy (LITT) is an emerging minimally invasive neurosurgical option for selected low-grade gliomas (LGG), particularly for deep-seated lesions or those located near eloquent brain areas. However, post-treatment MRI changes, and particularly spectroscopic and metabolic features (from Magnetic Resonance Spectroscopy (MRS)) of LITT-treated LGG remain insufficiently described. Objective: To describe the longitudinal MR morphological and metabolic changes observed after LITT in patients treated for LGG. Methods: In this prospective single-center study, 14 patients with WHO grade I or II gliomas treated with MRI-guided LITT at Amiens-Picardie University Hospital between July 2021 and March 2025 were included. All patients underwent multimodal MRI with conventional sequences and proton MR spectroscopy before treatment, immediately after LITT, at day 2-5, and during follow-up at 3, 6, 12, 18, and 24 months post-LITT, when available. Imaging analysis focused on lesion volumes assessed on diffusion-weighted imaging, T2-FLAIR, and contrast-enhanced T1-weighted imaging, together with spectroscopic metabolites ratios including mI/Cr, Lac/Cr, Cho/Cr, NAA/Cr, NAA/Cho and GLX/Cr. Results: Post-LITT imaging evolution showed a reproducible temporal pattern. Early imaging demonstrated the systematic appearance of transient peripheral diffusion hyperintensity and peripheral enhancement, together with an initial increase in T2-FLAIR volume, followed by progressive resorption over time. Spectroscopic analysis showed early transient increases in mI/Cr and Lac/Cr, whereas delayed follow-up was associated with a decrease in Cho/Cr, a trend toward re-elevation of NAA/Cr, and a sustained increase in NAA/Cho from month 12 onward. LITT treatment was well tolerated, with one transient complication among 14 patients. Tumor control was achieved in most patients, with two radiological recurrences and two clinical recurrences presenting as persistent epilepsy; all stabilized after adjuvant treatment. Conclusion: Combined morphological MRI and proton MR spectroscopy provide complementary information on post-LITT tissue effects evolution in LGG. This study highlights a typical longitudinal morphologic and metabolic imaging profile that may help improve interpretation of post-treatment follow-up. This LITT therapy could be added before and after radiotherapy. Further MRI and MRS follow-up would be necessary to establish long-term oncological efficacy.

We present a series of two patients with ependymomas treated with LITT, both of whom demonstrated only limited radiological and clinical responses. Due to these minor results, we plan to compare which tumor types generally respond well to LITT. Specifically, we want to evaluate in which tumors the ablation volume directly correlates with the final outcome.

Introduction Interstitial photodynamic therapy is an emerging loco-regional treatment for glioblastoma based on intracerebral illumination delivered through stereotactically implanted optical fibers. Despite encouraging oncological results, treatment-related morbidity remains significant [1], and the contribution of unintended light-induced thermal effects has never been experimentally investigated [2]. This study aimed to quantify ex vivo thermal effects of iPDT using MR-derived temperature map and numerical simulation to predict iPDT-induced in vivo thermal effects. Materials and Methods • Illumination (635 nm, 57 min) was performed in ex vivo calf brain (n=11) using three 3-cm diffusing fibers at three inter-probe distances (2, 1, and 0.6 cm). • Experiments were performed in a 1.5 T MRI scanner. Probe localization was confirmed on a pre-illumination T1w anatomical sequence, and temperature was monitored throughout using PRFS-based GRE-EPI thermometry [3,4] (3×20 min, 1.875×1.875×4 mm, 128×128×35 slices). • Numerical simulations were performed using COMSOL Multiphysics® based on a 3D anatomically-derived mesh (Fig. 1) and coupling the Bioheat Transfer Equation with the Photon Diffusion Equation. The model was first validated ex vivo across the three inter-probe distance conditions by comparison with MR- thermometry, then extended to prospective in vivo conditions by incorporating blood perfusion effects. Results • MR-thermometry enabled precise temperature monitoring during iPDT (accuracy ~0.5°C). • Cumulative heating was inter-probe distance-dependent, with peak temperatures of 43.7±0.7°C, 46.6±5.9°C, and 53.5±10.2°C at 2.0, 1.0, and 0.6 cm spacing, respectively. • The numerical model showed good agreement with MR-thermometry across all three conditions (RMSE: 1.34, 1.52, and 2.34°C at 2.0, 1.0, and 0.6 cm). (Fig. 2) • Prospective in vivo simulations incorporating blood perfusion predicted a maximum temperature rise of +10°C above baseline, suggesting a risk of thermal damage over a 1-hour illumination. (Fig. 3) Conclusion MRI thermometry proved feasible and precise for iPDT temperature monitoring. Ex vivo heating was non-negligible, and the ex vivo-validated numerical model predicted clinically relevant temperature rises in vivo, supporting its use as a digital twin for future patient-specific iPDT planning. References 1. Quach et al., J Neurooncol, 2023 2. Beck et al., Lasers Surg. Med., 2007 3. Odéen & Parker, Prog NMR Spectrosc, 2019 4. Ozenne et al., MRM, 2017

Introduction : 
Interstitial laser thermal ablation (LITT) is a minimally invasive surgical option for the treatment of brain tumors, particularly for deep-seated or difficult-to-access lesions. Tumors of the pineal region represent a major surgical challenge due to their complex anatomical relationships and deep location. Materials and Methods
 : We report our experience with robot-assisted LITT ablation of pineal tumors managed between 2020 and 2026. The data analyzed included preoperative symptoms, duration of preoperative follow-up, histopathology, presence and type of complications, associated surgeries, adjunct treatments, and clinical outcomes. Results
 : The technique was proposed in five cases of pineal tumors after multidisciplinary team discussion, including one case of post-LITT recurrence. Patients were followed for 30.4 months (range: 6–120) prior to LITT. Two laser probes were used in two patients to optimize tumor ablation, while the remaining three required only a single probe. Histopathological analyses obtained from initial biopsies revealed one pineocytoma with leptomeningeal dissemination, three pineal parenchymal tumors of intermediate differentiation, and one grade 3 papillary pineal tumor. Four patients initially presented with obstructive hydrocephalus requiring endoscopic third ventriculostomy. Transient morbidity was 20% (1 patient), consisting of postoperative hemiparesis that fully resolved with corticosteroid therapy. No permanent morbidity following LITT was reported. Lesion coverage was 83.8% (range: 70–99). All patients received adjuvant radiotherapy. One patient also received chemotherapy and subsequently died due to tumor progression. One patient remained clinically and radiologically stable for 4 years, then developed radiological progression requiring repeat LITT. The remaining patients are clinically and radiologically stable at last follow-up. Conclusion : 
Robot-guided LITT appears to be an additional and complementary therapeutic option for the management of pineal tumors when conventional surgery is associated with high morbidity. This technique can achieve results comparable to surgical resection with a low morbidity profile when tumor removal is difficult or not feasible. Further studies are needed to confirm these preliminary results. In addition, a larger-scale study comparing recurrence rates and tumor volume reduction between LITT combined with radiotherapy and radiotherapy alone would be of interest.

Background Laser interstitial thermal therapy (LITT) is an alternative to open surgery for both primary and secondary brain tumors. Clinically available LITT systems use different cooling systems that may impose additional risks and logistics. This is the first open-label phase 1-2 clinical investigation that explores the safety, feasibility and usability of the non-cooled Prism laser system for ablation of high-grade gliomas. Methods This is a single-center prospective study at the Neurosurgical department in Lund, Sweden. Patients with primary and recurrent glioblastoma were included after informed consent. Patients 18-80 years with lesions < 30 mm or < 10 cc were eligible. Single or multiple ablations were performed in a 3T MR suite using a MR compatible navigation system (ClearPoint® Neuro Navigation System) together with a new uncooled laser fiber, laser unit and MR thermometry. Functional outcomes were assessed at baseline and at 3 months. Results All 14 patients included completed the study. Three patients with primary glioblastoma and 11 patients with recurrent glioblastoma were treated with single or multiple laser thermal ablations. Median extent of ablation was 197%. Out of 22 AEs, 7 were neurological, all of which were graded as mild or moderate. The only procedure-related SAE was a pulmonary embolism that was resolved. None of the adverse events were device related. Conclusion The workflow was safe and feasible, with usability of the laser rated highly. Extent of ablation was high and quality of life as well as neurological and cognitive performance remained stable at 3 months.

Introduction Laser interstitial thermal therapy (LITT) is increasingly used for lesions located in deep or eloquent brain regions, where surgical resection carries a high risk of morbidity. In these patients, treatment is often limited to biopsy followed by chemoradiotherapy, without any local ablative or cytoreductive intervention. LITT may offer a minimally invasive alternative, although its role and optimal indications remain to be cleared. Methods We retrospectively reviewed consecutive patients treated with MRI-guided LITT between April 2022 and February 2025. All patients were considered not eligible for surgical resection and underwent stereotactic biopsy prior to treatment. Clinical and perioperative data were collected. Feasibility and safety were the main endpoints. Results Eight patients were included (mean age 49 years; median KPS 90). Lesions involved deep structures including the thalamus, mesencephalon, pineal region and corpus callosum. Histology included glioblastoma (n=4), low-grade gliomas (n=3) and one pineoblastoma. Mean lesion volume was 5.1 cm³ (range 1.3–10.2). Postoperative hydrocephalus occurred in 3 patients and was consistently associated with lesions adjacent to the ventricular system. One patient developed transient coma with hemiparesis and oculomotor deficits, partially improved at follow-up, while another patient experienced significant neurological worsening. Minor hemorrhagic events after biopsy and LITT did not require surgical intervention. Median postoperative stay in the neurosurgical ward was 10 days (range 8–33); 5 patients were discharged home and 3 required rehabilitation. Median treatment time was 415 minutes. Among glioblastoma patients, three received standard Stupp protocol, while one received reduced-dose therapy. Progression-free survival ranged from 56 to 102 days; two patients died during follow-up (overall survival 374 and 472 days). Conclusions LITT appears feasible in patients with deep-seated gliomas not suitable for resection. In our experience, complications were more closely related to lesion location, particularly proximity to the ventricular system, than to lesion size alone. In deep regions, even limited post-ablation edema may result in significant neurological impairment. Preliminary survival outcomes in glioblastoma patients appear comparable to surgical series, although interpretation is limited by the small sample size. Further studies are warranted to better define the role of LITT in this setting.

Abstract (English) Objectives: To evaluate the feasibility of the trans-rhino-septal approach under robot-assisted stereotactic guidance for deep skull base lesions, and to assess the potential role of Laser Interstitial Thermal Therapy (LITT) in the treatment of clival chordomas. Methods: Two clinical cases were analyzed. The first involved a retroclival chordoma treated with LITT; the second, a cystic craniopharyngioma located in the pre-pontine region, underwent a targeted aspiration. Both procedures were performed using a trans-rhino-septal approach under robot-assisted stereotactic navigation. Results: The procedures were completed without complications. The midline trajectory enabled direct access to the lesions while preserving surrounding critical structures. Postoperative MRI confirmed technical success. Short-term follow-up showed clinical and radiological response. Conclusion: This innovative strategy, combining a minimally invasive approach with high-precision technology, could represent a valuable therapeutic option for select deep skull base tumors, particularly chordomas. Further studies are needed to validate this approach. Keywords: chordoma, craniopharyngioma, LITT, trans-rhino-septal approach, robotic surgery, stereotaxy.

Background: Cerebral cavernomas are vascular malformations that can cause neurological problems such as hemorrhage and seizures. MRI is the preferred imaging modality, but hemosiderin deposits in cavernomas often lead to signal loss artifacts, complicating treatment planning. MRI-guided laser interstitial thermal therapy (MRIg-LITT) is an innovative, minimally invasive technique that offers a new approach to treating these lesions, but confirming ablation on MRI can be difficult due to these artifacts. Objective : Study and evaluate a volumetric T1-weighted subtraction technique after LITT ablation to enhance visualization of contrast uptake Methods: We evaluated six patients (3 female, 2 male ; media nage 31 yo) with symptomatic cerebral cavernomas treated with MRIg-LITT. The procedure involved an immediate post-treatment imaging to assess lesion reduction and edema. A volumetric T1-weighted subtraction technique was employed after ablation to enhance visualization of contrast uptake. Results: Complete thermal ablation was confirmed by diffusion hyperintensity and gadolinium-enhanced peripheral rings, despite susceptibility artifacts. T1-weighted volumetric subtraction sequences effectively minimized artifacts and improved visualization of the lesions. No hemorrhagic complications occurred, and expected post-LITT edema was managed with corticotherapy. Conclusion: T1-weighted volumetric subtraction sequences are valuable in MRIg-LITT for treating cerebral cavernomas, as they reduce magnetic susceptibility artifacts and enhance contrast visualization.

Introduction: Brainstem cavernomas are rare but potentially serious lesions due to the risk of hemorrhage. Their therapeutic management remains controversial. Surgical resection carries a high risk of morbidity, and efficacy of radiosurgery is still debated. Robot-guided laser interstitial thermal therapy (LITT), using the Rosa system and low-temperature ablation, offers a minimally invasive alternative with potentially reduced morbidity. Method: We report a retrospective serie of three patients treated at Amiens University Hospital in 2024. Mean age was 54 years. All patients underwent LITT after at least one bleeding episode (two episodes in two patients, one in the third). A single laser probe was precisely positioned using the Rosa robot, and ablation was performed under real-time temperature control with VISUALASE system (Medtronic). Complete ablation was monitored by intraoperative MRI using FLAIR and diffusion sequences and T1+gado. Results: Two patients had pre-existing oculomotor deficits; one experienced transient worsening postoperatively (alternating syndrome), which partially improved with corticosteroids. No patient experienced a loss of autonomy. Mean follow-up was 13 months, with no rebleeding observed. Conclusion: LITT combined with robotic guidance and low-temperature control, appears to be a safe and effective minimally invasive option for treating brainstem cavernomas. Larger studies are needed to validate these results.

INTRODUCTION Magnetic resonance imaging–guided laser interstitial thermal therapy (MRIgLITT) is increasingly recognized as a safe and effective minimally invasive treatment for drug-resistant focal epilepsy, particularly in cases involving deep-seated lesions such as insular epilepsy. METHODS We prospectively collected data from all patients treated with MRIgLITT at the Pediatric Epilepsy Surgery Unit of Hospital Sant Joan de Déu (Barcelona) since 2019. This study summarizes our experience in the management of insular epilepsy using this technique. All patients underwent a comprehensive pre-surgical neuropsychological evaluation, followed by clinical assessment at 6 months and neuropsychological follow-up at 1 and 2 years postoperatively. RESULTS Nine MRIgLITT procedures for insular epilepsy were performed in nine patients (6 females, 3 males), aged 7–17 years (mean age: 9 years). Five procedures targeted the left hemisphere, including two in the dominant hemisphere; both patients developed transient transcortical aphasia. Four patients underwent prior stereoelectroencephalography (SEEG). Concurrent biopsy during MRIgLITT revealed three low-grade gliomas and one focal cortical dysplasia (FCD). In the remaining five cases, FCD was suspected, based on imaging and electroclinical data, although no biopsy was performed. Two cases were part of a staged surgical strategy. From a technical standpoint, two laser fibers were used in three cases, four fibers in one case, and five fibers in another. Most trajectories were planned as oblique to optimize lesion coverage. At a follow-up ranging from 1 to 5 years, six patients achieved seizure freedom, while the remaining three showed a marked reduction in seizure frequency and severity. Neuropsychological outcomes demonstrated improvement in 4/9 patients and stability in 2/9; one patient was lost to follow-up. Formal neuropsychological reassessment is pending in two patients, although both clinical evaluation and family reports suggest improvement. CONCLUSIONS Our experience supports MRIgLITT as a safe and effective treatment for pediatric insular epilepsy. Its minimally invasive nature, together with the ability to obtain a histological diagnosis within the same procedure, enhances its clinical utility. Although longer follow-up is needed, MRIgLITT represents our preferred treatment option for selected patients with focal insular lesions.

Background: Cavernous malformations in children may cause seizures, neurological deficits, and intracranial hemorrhage. Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive alternative, particularly for lesions in high-risk locations. Objective: To evaluate the safety and efficacy of LITT in pediatric patients with cavernous malformations. Methods: A retrospective analysis was performed on 6 pediatric patients (5 males, 1 female; mean age 13.2 years) treated with LITT at a single center. Lesions were located in the frontal (n=4) and parietal (n=2) lobes. Clinical presentation, surgical parameters, and postoperative clinical and radiological outcomes were analyzed. Results: All lesions showed evidence of prior hemorrhage. In 4/6 patients, lesions were located adjacent to the ventricular system, conferring an increased risk of intraventricular bleeding. Two patients were treated for drug-resistant epilepsy, both achieving seizure freedom (Engel class I). Among the remaining patients, one presented with post-hemorrhagic hemiparesis, two with headaches, and one lesion was incidentally detected but qualified for treatment due to its proximity to the ventricular system. Complete ablation was achieved in 5/6 patients, with possible minimal residual lesion in one case. Postoperative imaging remained stable, with at least 12 months of follow-up available in 5/6 patients. One complication occurred: a venous infarction of the frontal lobe due to occlusion of an associated developmental venous anomaly (DVA), without clinical sequelae. No other complications were observed. Conclusions: LITT appears to be a safe and effective minimally invasive option for pediatric cavernous malformations, particularly for hemorrhagic and periventricular lesions. High rates of complete ablation, stable radiological outcomes, and excellent seizure control support its role in selected high-risk cases.

Introduction: Hypothalamic hamartomas (HH) can cause pharmacoresistant epilepsy and may be treated by Laser Interstitial Thermal Therapy (LITT), a recent minimally invasive Magnetic Resonance Imaging (MRI)-guided neurosurgical procedure. To our knowledge, no previous studies dealing with spectroscopic and metabolic patterns of treated HH by LITT have been published. Purpose: The aim of this study was to characterize the evolution of MRI and Magnetic Resonance Spectroscopy (MRS) patterns during a follow-up of LITT-treated HH. Methods: 13 patients underwent MRI and proton MRS exams on 1.5T GE MRI. MRI and MRS data were collected pre-operatively, at immediate post-operative, at D3/D5 post-operative, at M3, M6, M14, M22, M31 and M40 post-operative. Results: Clinical LITT efficiency was based on the reduction of the number of epilepsy crises and the improvement of electroencephalogram (EEG) patterns. MRI results revealed that the lesion volume decreased of about 26 – 86 % during follow-up. Post-surgical edema continuously decreased during the follow up. An increased peripheral diffusion hypersignal volume was measured at immediate post-operative and at D3/D5 post-operative, which then tended to normalize. MRS results, based on metabolites ratios quantification, depicted a decreased N-Acetyl-Aspartate (NAA) to Creatine (Cr) ratio (10/13 patients) in the treated tissue at D3/D5 postoperative, an increased Choline (Cho) to Cr ratio and increased lactate to Cr ratio at immediate postoperative and at D3/D5 post-operative controls, which improved over time. Moreover, MRS depicted a glial reaction during the LITT procedure in the treated tissue in 12/13 patients, that was decreased at D3/D5 and normalized after. Discussion and conclusion: The present results provide an overview of the morphological and metabolic features evolution of the LITT-treated HH. From our experience, the study of these changes was relevant to better assess LITT efficiency on pharmacoresistant epilepsy. Further investigations with a larger data follow-up, as well as an evaluation of the effect of LITT- treated HH on distant brain regions could be carried out. Relationships between MRI/MRS features and clinical and EEG data will be studied to improve the analysis, interpretation, and monitoring of this innovative minimally invasive neurosurgical procedure.

Hypothalamic hamartoma (HH) is associated with drug-resistant epilepsy, often requiring surgical treatment. Interstitial laser thermotherapy (LiTT) is a minimally invasive technique increasingly used for HH. We report our experience with nine patients treated between 2019 and 2023 at Amiens University Hospital using LiTT with robotic assistance. Probe placement was performed using the Rosa® robot, and ablation was conducted with a VISUALASE® system (Medtronic) at low temperature to preserve adjacent structures (e.g., hypothalamus), maintaining surrounding tissue temperatures below 45°C. Ablation completeness was assessed perioperatively using diffusion and FLAIR MRI sequences. The mean patient age was 13 years; two patients underwent two procedures. Lesions were classified per modified Delalande system. No bleeding or infections occurred. Ablation was complete in eight cases and >95% in one. Clinical outcomes showed that 88.8% improved: six patients were ILAE class 1, one class 2, one class 4, and one class 5. No postoperative neurocognitive or behavioral complications were observed; seven patients had improved cognition or behavior. Two endocrine side effects were reported (thyroid insufficiency and bulimia with preserved weight). These results support the efficacy and safety of robot-assisted, low-temperature LiTT in managing HH with minimal morbidity.

Hypothalamic hamartoma (HH) is a non-neoplastic malformative lesion with intrinsic epileptogenic properties, frequently associated with gelastic seizures and progression toward drug-resistant epileptic encephalopathy. Although disconnective surgery or resection represents the gold standard, Delalande Type III cases present significant technical challenges due to the involvement of the third ventricle and the subthalamic region. We report the case of a 17-year-old patient suffering from refractory epilepsy symptomatic of Type III HH. Patient underwent two laser endoscopic disconnection procedures (2019, 2020) with transient clinical benefit. In 2021, a subtotal resection and microsurgical disconnection via a subfrontal trans-lamina terminalis approach was performed followed by few months of seizure relief. Stereotactic radiosurgery (Gamma Knife) was administered in 2022 to control seizure recurrence. In April 2024, a further endoscopic excision using the endoscopic ultrasonic aspirator was required, followed by a transient improve of the seizure. Given the recurrence in seizure frequency (up to 30 episodes/day), the patient was candidate for stereotactic Laser-Induced Interstitial Thermotherapy (LITT) in January 2026. Postoperative monitoring showed a reduction in seizure frequency and a shift in semiology (brief seizures without impairment of consciousness). A subsequent partial relapse of paroxysmal phenomena led to a second LITT session targeting the residual lesional core which was performed 2 months later with clinical and seizure improvement. Throughout each stage of the clinical course, a response pattern emerged characterized by an initial phase of seizure freedom or a marked reduction in seizure burden, systematically followed by symptomatic recurrence, suggesting a high capacity for epileptogenic network reorganization. The management of drug-resistant HH may necessitate a dynamic and multimodal therapeutic paradigm. In cases characterized by complex lesional and genetic architecture, a single surgical procedure may prove insufficient in the long term. The iterative integration of microsurgical, endoscopic, and minimally invasive ablative techniques (LITT) appears necessary to progressively modulate the epileptogenic network. This case demonstrates that the persistence of seizure should not be considered a therapeutic failure per se, but rather an indication for a combined functional debulking strategy aimed at the cumulative reduction of seizure.

Background Laser Interstitial Thermal Therapy (LITT) is an emerging minimally invasive technique increasingly adopted in neuro-oncology for deep-seated, recurrent, and surgically high-risk lesions. However, access to LITT remains limited in many regions, including the MENA region. We report the establishment of a LITT program and our early single-center experience using MRI-guided LITT across a mixed adult and pediatric neuro-oncology population. Methods We conducted a prospective observational case series of 15 consecutive patients undergoing MRI-guided LITT using the Visualase system over a 14-month period at a tertiary referral oncology center in the MENA region (Jordan). The cohort included 7 adults and 8 pediatric patients. Indications comprised temporal lobe low-grade gliomas, hypothalamic lesions including hypothalamic hematoma, recurrent high-grade gliomas, and intracranial metastases in surgically challenging locations. Median lesion size was 1.5 cm. All cases were performed using a single-session workflow combining stereotactic robotic biopsy and LITT with real-time MR thermometry. Perioperative safety, clinical outcomes, and early radiological response were assessed. Results LITT was successfully completed in all patients with accurate catheter placement and effective thermal ablation. Median length of hospital stay was 1 day. No major intraoperative complications were observed. Transient postoperative neurological deficits occurred in a one patient and resolved with conservative management. Notably, no routine perioperative corticosteroid use was required. Early postoperative imaging demonstrated satisfactory ablation volumes consistent with treatment planning. The single-session biopsy and ablation approach enabled efficient diagnosis and treatment while minimizing patient morbidity and healthcare utilization. Conclusion This study represents an early regional experience establishing a LITT program in the MENA region , demonstrating feasibility of a single-session biopsy and treatment workflow in both adult and pediatric neuro-oncology patients. It demonstrates that MRI-guided LITT using Visualase is safe, feasible, and efficient. The ability to combine biopsy and definitive treatment in a single minimally invasive session, with short hospitalization and minimal reliance on corticosteroids, supports broader adoption of LITT in resource-variable settings.

Introduction: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) thalamotomy is an emerging minimally invasive treatment for disabling, drug-resistant essential tremor. Although its clinical efficacy has been demonstrated, its effects on the structures of the cerebello–thalamo–cortical network remain incompletely understood. This study aimed to characterize metabolic changes in the primary motor cortex following MRgLITT thalamotomy using proton MR spectroscopy. Methods: We retrospectively analyzed 21 patients who underwent MRgLITT thalamotomy at Amiens University Hospital between 2019 and 2025. MR spectroscopy was performed preoperatively, immediately postoperatively, between postoperative days 2-5, and at 6 and 12 months. The metabolites quantification included choline (Cho), creatine (Cr), N-acetylaspartate (NAA), myo-inositol (mI), Glutamine-Glutamate Complex (GLX), lipids, lactate, and additional metabolites such as acetate (Ac). Results: An increase in the NAA/Cr ratio was observed in the primary motor cortex. This increase was progressive over time, reaching a 21% elevation at 12 months, with mean values rising from 1.49 in the immediate postoperative period to 1.81 at 12 months (p = 0.04). No statistically significant changes were observed in other metabolite ratios, including Cho/Cr (p = 0.08), Lac/Cr (p = 0.393), and mI/Cr (p = 0.4), which are typically altered when spectroscopic measurements are performed at the site of thalamotomy. Conclusion: MRgLITT induces dynamic metabolic changes remote from the ventral intermediate nucleus of the thalamus, particularly in the primary motor cortex, where a progressive increase in the NAA/Cr ratio is observed. These findings may suggest an improvement in neuronal function in this region and may alternatively reflect cortical plasticity or functional reorganization of the cerebello–thalamo–cortical network.

Introduction Essential tremor (ET) often resists medical therapy. Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) is a minimally invasive technique allowing real-time MRI thermometry for precise thalamotomy. We evaluated the 12-month efficacy and safety of unilateral MRgLITT thalamotomy in 21 pharmacoresistant ET patients. Methods Patients underwent unilateral MRgLITT thalamotomy (ROSA robot, Visualase system). Assessments at baseline, 3, and 12 months used the Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS). Primary outcome was the treated limb FTM-TRS score (rest, posture, action, drawing). Secondary outcomes included Quality of Life in Essential Tremor Questionnaire (QUEST-SI), Patient Global Impression of Change (P-CGI), Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and adverse events (AE). Linear mixed-effects models were used for analysis. Results Twenty-one patients (mean age 67.2+/-12.8 years; 12 males; 17 right-handed) underwent unilateral thalamotomy (17 left). Treated limb FTM-TRS scores decreased by 75.1% (14.0+/-3.1 baseline vs 3.5+/-1.6 at 12 months; p < 0.001). All patients (100%) achieved >50% improvement. QUEST-SI improved from 41.2+/-15.7% to 18.0+/-14.6% (p < 0.001). Mean satisfaction (P-CGI) was 82.0+/-20.7%. Transient AEs (3 months: 71.4%) primarily included proprioceptive and balance disorders; only one patient (4.8%, gait ataxia) had persistent symptoms at 12 months. MoCA decreased slightly (25.4+/-3.1 to 23.9+/-3.5; p = 0.024) while MMSE remained stable (27.2+/-2.3 vs 26.5+/-2.6; p = 0.158). Conclusion Unilateral MRgLITT thalamotomy provides robust, sustained tremor relief and improved quality of life for pharmacoresistant ET. Despite the small cohort, it represents a safe, promising alternative to other surgical techniques. Larger longitudinal studies are warranted to establish its long-term role.

Stereotactic mesencephalotomy is a neurosurgical technique designed to sever spinothalamic pain transmission pathways for medically intractable pain. This report presents the first case of Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) mesencephalotomy for severe malignant pain due to metastatic melanoma. The procedure significantly reduced the patient’s pain, with a postoperative visual analog scale (VAS) score decreasing from > 7 to < 3. No adverse effects were observed. The case underscores the potential of MRgLITT mesencephalotomy as a precise, minimally invasive option for pain management in palliative care settings