Background: Laser interstitial thermal therapy (LITT) is a minimal invasive neurosurgical technique for the treatment of brain tumors. Results of LITT have been reported in a case series of patients with deep seated and/or recurrent glioblastoma or cerebral metastases. With this review we aim to summarize the currently available evidence regarding safety and effectiveness of LITT in patients with newly diagnosed glioblastoma (nGBM). Methods: A literature search was performed using electronic databases (PubMed and Embase). Papers were assessed for the methodological quality using the Risk Of Bias In Non- randomised Studies - of Interventions (ROBINS-I) tool, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess the quality of the evidence. Results: We identified 835 papers of which only 11 articles were eligible for our review. All papers suffered from serious or critical risk of bias, and the quality of evidence was graded as very low according to the GRADE criteria. None of the studies was randomized and reporting of confounders and other parameters was poor. Median overall survival (OS) ranged from 4.1 to 32 months and progression free survival (PFS) from 2 to 31 months. The mean complication rate was 33.7%. No quality of life or cost-effectiveness data were reported. Conclusions: Due to the low quality of the studies, it is not possible to draw firm conclusions regarding the (cost) effectiveness of LITT in patients with newly diagnosed glioblastoma. The low quality of evidence shows the need for a well-designed prospective multicenter randomized controlled trial.

Purpose: Laser interstitial thermal therapy (LITT) is increasingly being used in the treatment of brain tumors, whereas high-quality evidence of its effectiveness is lacking. This pilot examined the feasibility of conducting a randomized controlled trial (RCT) in patients with irresectable newly diagnosed glioblastoma (nGBM), and generated data on technical feasibility and safety. Methods: We included patients with irresectable nGBM with KPS ≥ 70 and feasible trajectories to ablate ≥ 70% of the tumor volume. Patients were initially randomized to receive either biopsy combined with LITT or biopsy alone, followed by chemoradiation (CRT). Randomization was stopped after 9 patients as the feasibility endpoint with respect to willingness to be randomized was met. Main endpoints were feasibility of performing an RCT, technical feasibility of LITT and safety. Follow-up was 3 months. Results: A total of 15 patients were included, of which 10 patients received a biopsy followed by LITT and 5 patients a biopsy. Most patients were able to complete the follow-up procedures (93% clinical, 86% questionnaires, 78% MRI). Patients were planned within 3 weeks after consultation (median 12 days, range 8–16) and no delay was observed in referring patients for CRT (median 37 days, range 28–61). Two CD ≥ 3 complications occurred in the LITT arm and none in the biopsy arm. Conclusion: An RCT to study the effectiveness of LITT in patients with an irresectable nGBM seems feasible with acceptable initial safety data. The findings from this pilot study helped to further refine the design of a larger full-scale multicenter RCT in the Netherlands. Protocol and study identifier: The current study is registered at clinicaltrials.gov (EMITT pilot study, NTR: NCT04596930). Graphical

The authors present a case of a young girl affected by a syndromal hydrocephalus who developed a bilateral ossified chronic subdural hematoma with the typical radiological appearance of "the armored brain". Bilateral calcified chronic subdural hematoma is a rare complication of ventriculoperitoneal shunt. There is controversy in the treatment, but most published literature discourages a surgical intervention to remove the calcifications.

Purpose: This registry-based study aims to examine the variation in biopsy and resection indications for glioblastoma patients across Dutch hospitals and to identify patient- and hospital-related factors associated with the surgical treatment. Methods: Data from all 7443 adults with first-time glioblastoma surgery at 12 hospitals were obtained from the prospective population-based Quality Registry Neurosurgery in the Netherlands between 2011 and 2021. Patients were stratified by either biopsy or resection. We analyzed variation in American Association of Anesthesiologist (ASA) classification, Karnofsky Performance Score (KPS), gender and age distribution between the different centers. Between-hospital variation in biopsy percentage was analyzed using a funnel plot. Logistic regression was used to identify associated patient- and hospital-related factors. Results: In total, 32% of the newly diagnosed glioblastoma patients underwent a biopsy, with wide variations between the different centers (23–56%). Patients-related variables such as higher age or ASA classification and lower KPS were significantly associated with the indication for biopsy. After correction for these factors, between-hospital variation persisted, with two institutes performing more biopsies than expected and one less than expected. Median overall survival was 12.5 months (95% CI 12.2–12.9) in the resection group and 5.6 months (95% CI 5.1–6) in the biopsy group, with wide variations between the different centers. Conclusion: A substantial between-hospital variation in biopsy percentages was found. Patient factors (age, ASA classification and KPS) but also hospital factors (such as academic setting) impact surgical decisions. Variation persisted also after correction for potential confounders, indicating that other factors play a role in decision-making.

OBJECTIVE: Targeting accuracy presents a key factor in achieving maximal safe ablation in laser interstitial thermal therapy (LITT). The VarioGuide system has proven precise for brain biopsies, but data showing its accuracy in combination with LITT are limited. The aim of this study was to determine the phantom and in vivo accuracy of LITT probe placement using the VarioGuide system and to evaluate the effect of targeting error on maximum possible ablation volume. METHODS: Stereotactic LITT probe placement was performed using the VarioGuide system in 3 phantom skulls. The same system was used in 10 patients treated with LITT, for which data were retrospectively analyzed. Target point error (TPE), target depth deviation (TDD), target lateral deviation (TLD), and angular deviation (AD) were derived from intraprocedural MRI scans of both the phantom and in vivo trajectories. In vivo, the effect of targeting error on the maximum reachable ablation was calculated as the difference between the planned maximal achievable tumor ablation (PTA) and the actual maximal achievable tumor ablation (ATA). RESULTS: In total, 24 phantom and 16 in vivo trajectories were analyzed. In the phantom setting, the median TPE was 3.3 mm and median AD was 1.9°. Targeting accuracy significantly decreased for longer trajectories and those less perpendicular to the skull. In patients, the authors observed a comparable median TPE of 4.0 mm but significantly higher AD of 3.2°. In vivo, targeting inaccuracy resulted in a median decrease in maximum achievable ablation volume of 6% as compared to the planned trajectory. CONCLUSIONS: The authors’ study indicates that utilizing the VarioGuide system in combination with LITT yields an average targeting error as large as 4 mm, which was smaller for shorter and straighter trajectories. In patients, targeting inaccuracy resulted in a median 6% decrease of the planned tumor ablation volume. These are important factors that should be considered in optimal case planning and patient selection in LITT.

In the last decades, the application of stereotactic laser ablation (SLA) for the treatment of intracranial tumours has been growing, even though comparative trials are lacking. Our aim was to investigate the familiarity with SLA of neurosurgeons in Europe and their opinion regarding potential neuro-oncological indications. Furthermore, we investigated treatment preferences and variability for three exemplar neuro-oncological cases and willingness to refer for SLA. A 26-questions survey was mailed to members of the EANS neuro-oncology section. We presented three clinical cases of respectively deep-seated glioblastoma, recurrent metastasis and recurrent glioblastoma. Descriptive statistics was applied to report results. 110 respondents completed all questions. Recurrent glioblastoma and recurrent metastases were regarded as the most feasible indications for SLA (chosen by 69% and 58% of the respondents) followed by newly diagnosed high-grade gliomas (31%). Seventy percent of respondents would refer patients for SLA. The majority of respondents would consider SLA as a treatment option for all three presented cases: 79% for the deep-seated glioblastoma case, 65% for the recurrent metastasis case and 76% for the recurrent glioblastoma case. Among respondents who wouldn't consider SLA, preference for standard treatment and lack of clinical evidence were reported as the main reasons. Most of respondents considered SLA as a treatment option for recurrent glioblastoma, recurrent metastases and newly diagnosed deep-seated glioblastoma. At the moment the current evidence to support such a treatment is very low. Comparative prospective trials are needed to support the use of SLA and determine proper indications.