Phantom and in vivo accuracy of frameless optical navigation in stereotactic laser interstitial thermal therapy.

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.

MR-guided LITT therapy in patients with primary irresectable glioblastoma: a prospective, controlled pilot study.

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).

Overview of the microanatomy of the human brainstem in relation to the safe entry zones.

OBJECTIVE: The primary objective of this anatomical study was to apply innovative imaging techniques to increase understanding of the microanatomical structures of the brainstem related to safe entry zones. The authors hypothesized that such a high-detail overview would enhance neurosurgeons' abilities to approach and define anatomical safe entry zones for use with microsurgical resection techniques for intrinsic brainstem lesions. METHODS: The brainstems of 13 cadavers were studied with polarized light imaging (PLI) and 11.7-T MRI. The brainstem was divided into 3 compartments-mesencephalon, pons, and medulla-for evaluation with MRI. Tissue was further sectioned to 100 µm with a microtome. MATLAB was used for further data processing. Segmentation of the internal structures of the brainstem was performed with the BigBrain database. RESULTS: Thirteen entry zones were reported and assessed for their safety, including the anterior mesencephalic zone, lateral mesencephalic sulcus, interpeduncular zone, intercollicular region, supratrigeminal zone, peritrigeminal zone, lateral pontine zone, median sulcus, infracollicular zone, supracollicular zone, olivary zone, lateral medullary zone, and anterolateral sulcus. The microanatomy, safety, and approaches are discussed. CONCLUSIONS: PLI and 11.7-T MRI data show that a neurosurgeon possibly does not need to consider the microanatomical structures that would not be visible on conventional MRI and tractography when entering the mentioned safe entry zones. However, the detailed anatomical images may help neurosurgeons increase their understanding of the internal architecture of the human brainstem, which in turn could lead to safer neurosurgical intervention.

Between-hospital variation in rates of complications and decline of patient performance after glioblastoma surgery in the dutch Quality Registry Neuro Surgery.

INTRODUCTION: For decisions on glioblastoma surgery, the risk of complications and decline in performance is decisive. In this study, we determine the rate of complications and performance decline after resections and biopsies in a national quality registry, their risk factors and the risk-standardized variation between institutions. METHODS: Data from all 3288 adults with first-time glioblastoma surgery at 13 hospitals were obtained from a prospective population-based Quality Registry Neuro Surgery in the Netherlands between 2013 and 2017. Patients were stratified by biopsies and resections. Complications were categorized as Clavien-Dindo grades II and higher. Performance decline was considered a deterioration of more than 10 Karnofsky points at 6 weeks. Risk factors were evaluated in multivariable logistic regression analysis. Patient-specific expected and observed complications and performance declines were summarized for institutions and analyzed in funnel plots. RESULTS: For 2271 resections, the overall complication rate was 20 % and 16 % declined in performance. For 1017 biopsies, the overall complication rate was 11 % and 30 % declined in performance. Patient-related characteristics were significant risk factors for complications and performance decline, i.e. higher age, lower baseline Karnofsky, higher ASA classification, and the surgical procedure. Hospital characteristics, i.e. case volume, university affiliation and biopsy percentage, were not. In three institutes the observed complication rate was significantly less than expected. In one institute significantly more performance declines were observed than expected, and in one institute significantly less. CONCLUSIONS: Patient characteristics, but not case volume, were risk factors for complications and performance decline after glioblastoma surgery. After risk-standardization, hospitals varied in complications and performance declines.

Selective Intensive Care Unit Admission After Adult Supratentorial Tumor Craniotomy: Complications, Length of Stay, and Costs.

BACKGROUND: Admitting patients to an intensive care or medium care unit (ICU/MCU) after adult supratentorial tumor craniotomy remains common practice even though some studies have suggested lower level care is sufficient for selected patients. We have introduced a "no ICU, unless" policy for tumor craniotomy patients. OBJECTIVE: To provide a quieter postoperative environment for patients, reduce the burden on the ICU department, and to evaluate whether costs can be reduced. METHODS: A cohort study was performed comparing patients that underwent tumor craniotomy for supratentorial tumors during 1 yr after introduction (n = 109) of the new policy with the year before (n = 107). Rate of complications was evaluated, as was the length of stay and patient satisfaction using qualitative evaluation. Finally, costs were evaluated comparing the situation before and after implementation of the new protocol. RESULTS: A reduction in ICU/MCU admittance from 64% to 24% of patients was found resulting in 13.3% cost reduction (€1950 per case), without increasing the length of stay at the ward. The length of stay in the hospital was similar. Complications were significantly reduced after implementing the new policy (0.98 vs 0.53 per patient, P = .003). Patients that were interviewed after the new policy reported feeling safe and at ease at the ward. CONCLUSION: Changing our policy from "ICU, unless" to "no ICU, unless" reduced complication rates and length of stay in the hospital while keeping patients satisfied. Hospital costs related to the admission have been significantly reduced by the new policy.