Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma and Radiation Necrosis: A Single-Surgeon Case Series.

OBJECTIVE: To evaluate long-term clinical outcomes among patients treated with laser interstitial thermal therapy (LITT) for predicted recurrent glioblastoma (rGBM). METHODS: Patients with rGBM treated by LITT by a single surgeon (2013-2020) were evaluated for progression-free survival (PFS), overall survival (OS), and OS after LITT. RESULTS: Forty-nine patients (33 men, 16 women; mean [SD] age at diagnosis, 58.7 [12.5] years) were evaluated. Among patients with genetic data, 6 of 34 (18%) had IDH-1 R132 mutations, and 7 of 21 (33%) had MGMT methylation. Patients underwent LITT at a mean (SD) of 23.8 (23.8) months after original diagnosis. Twenty of 49 (40%) had previously undergone stereotactic radiosurgery, 37 (75%) had undergone intensity-modulated radiation therapy, and 49 (100%) had undergone chemotherapy. Patients had undergone a mean of 1.2 (0.7) previous resections before LITT. Mean preoperative enhancing and T2 FLAIR volumes were 13.1 (12.8) cm3 and 35.0 (32.8) cm3, respectively. Intraoperative biopsies confirmed rGBM in 31 patients (63%) and radiation necrosis in 18 patients (37%). Six perioperative complications occurred: 3 (6%) cases of worsening aphasia, 1 (2%) seizure, 1 (2%) epidural hematoma, and 1 (2%) intraparenchymal hemorrhage. For the rGBM group, median PFS was 2.0 (IQR, 4.0) months, median OS was 20.0 (IQR, 29.5) months, and median OS after LITT was 6.0 (IQR, 10.5) months. For the radiation necrosis group, median PFS was 4.0 (IQR, 4.5) months, median OS was 37.0 (IQR, 58.0) months, and median OS after LITT was 8.0 (IQR, 23.5) months. CONCLUSIONS: In a diverse rGBM cohort, LITT was associated with a short duration of posttreatment PFS.

Long-Term Follow-up of 25 Cases of Biopsy-Proven Radiation Necrosis or Post-Radiation Treatment Effect Treated With Magnetic Resonance-Guided Laser Interstitial Thermal Therapy.

BACKGROUND: Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is a minimally invasive surgical treatment for progressive neoplasms and post-radiation treatment effect (PRTE). OBJECTIVE: To evaluate the radiographic response and efficacy of MRgLITT for biopsy-confirmed PRTE and the quality-of-life outcomes of patients following MRgLITT. METHODS: We conducted a single-center retrospective study of radiographic responses and clinical outcomes of 25 patients with previously treated primary or secondary brain neoplasms (World Health Organization grades 4 [n = 8], 3 [n = 5], 2 [n = 5]) and metastatic brain tumors (n = 7). MRgLITT was applied directly following stereotactic needle biopsy confirming PRTE without any evidence of tumor presence. RESULTS: Mean overall survival times (months) for grades 4 and 3 and for metastatic brain tumors were 39.2 (standard error [SE], 7.6; 95% confidence interval [CI], 24.3-54.1), 29.1 (SE, 7.7; 95% CI, 14.0-44.2), and 55.9 (SE, 10.0; 95% CI, 36.3-75.4), respectively. Mean progression-free survival times after MRgLITT were 9.1 (SE, 3.6; 95% CI, 2.1-16.1), 8.5 (SE, 2.4; 95% CI, 3.9-13.2), and 11.4 (SE, 3.9; 95% CI, 3.8-19.0), respectively. Mean survival times after MRgLITT were 13.1 (SE, 2.3; 95% CI, 8.5-17.6), 12.2 (SE, 4.0; 95% CI, 4.4-20.0), and 19.2 (SE, 5.3; 95% CI, 8.9-29.6), respectively. The SF-36 indicated significant overall effects on mental health (P = .029) and vitality (P = .005). CONCLUSION: MRgLITT may be a viable option for patients with symptomatic advancing PRTE and is less invasive than open craniotomy. Although our results suggest a positive effect for MRgLITT on PRTE, prospective randomized trials with larger numbers of patients are needed to validate the study results. ABBREVIATIONS: cRBV, relative cerebral blood volumeHIF1a, hypoxia-inducible factor 1aIMRT, intensity-modulated radiation therapyKPS, Karnofsky Performance StatusLITT, laser-induced thermal therapyMBT, metastatic brain tumorMRgLITT, magnetic resonance-guided laser-induced thermal therapyPRTE, post-radiation treatment effectSRS, stereotactic radiosurgeryVEGF, vascular endothelial growth factorWBXRT, whole brain radiation therapy.

Physiology and pathophysiology of cortico-basal ganglia-thalamocortical loops: theoretical and practical aspects.

A new theoretical framework is used to analyze functions and pathophysiological processes of cortico-basal ganglia-thalamocortical loops and to demonstrate the hierarchical relationships between various loops. All hierarchical levels are built according to the same functional principle: Each loop is a neural optimal control system (NOCS) and includes a model of object behavior and an error distribution system. The latter includes dopaminergic neurons and is necessary to tune the model to a controlled object (CO). The regularities of pathophysiological processes in NOCSs are analyzed. Mechanisms of current functional neurosurgical procedures like lesioning and deep brain stimulation (DBS) of various basal ganglia structures and neurotransplantation are described based on proposed theoretical ideas. Parkinson's disease (PD) is used to exemplify clinical applications of the proposed theory. Within the proposed theoretical framework, PD must be considered as a disease of the error distribution system. The proposed theoretical views have broad fundamental and clinical applications.