Radical supramaximal resection for newly diagnosed left-sided eloquent glioblastoma: safety and improved survival over gross-total resection.

OBJECTIVE: Supramaximal resection (SMR) has arisen as a possible surrogate to gross-total resection (GTR) to improve survival in newly diagnosed glioblastoma (nGBM). However, SMR has traditionally been limited to noneloquent regions and its feasibility in eloquent nGBM remains unclear. The authors conducted a retrospective multivariate propensity-matched analysis comparing survival outcomes for patients with left-sided eloquent nGBM undergoing SMR versus GTR. METHODS: A retrospective review was performed of all patients at our institution who underwent SMR or GTR of a left-sided eloquent nGBM during the period from 2011 to 2020. All patients underwent some form of preoperative or intraoperative functional mapping and underwent awake or asleep craniotomy (craniotomy under general anesthesia); however, awake craniotomy was performed in the majority of patients and the focus of the study was SMR achieved via awake craniotomy and functional mapping with lesionectomy and additional peritumoral fluid attenuated inversion recovery (FLAIR) resection. Propensity scores were generated controlling for age, tumor location, and preoperative Karnofsky Performance Status (KPS) score with the nearest-neighbor algorithm. RESULTS: A total of 102 patients (48 SMR, 54 GTR) were included in this study. The median overall survival (OS) and progression-free survival (PFS) for patients receiving SMR were 22.9 and 5.1 months, respectively. Propensity matching resulted in a final cohort of 27 SMR versus 27 GTR patients. SMR conferred improved OS (21.55 vs 15.49 months, p = 0.0098) and PFS (4.51 vs 3.59 months, p = 0.041) compared to GTR. There was no significant difference in postoperative complication rates or KPS score in SMR compared with GTR patients (p = 0.236 and p = 0.736, respectively). In patients receiving SMR, improved OS and PFS showed a dose-dependent relationship with extent of FLAIR resection (EOFR) on log-rank test for trend (p < 0.001). CONCLUSIONS: SMR by means of awake craniotomy with functional mapping for left-sided eloquent nGBM is safe and confers a survival benefit compared to GTR obtained with lesionectomy alone while preserving postoperative neurological integrity. When tolerated, greater EOFR with SMR may be associated with improved survival.

A Cohort Study on Prognostic Factors for Laser Interstitial Thermal Therapy Success in Newly Diagnosed Glioblastoma.

BACKGROUND: Laser interstitial thermal therapy (LITT) is a promising approach for cytoreduction of deep-seated gliomas. However, parameters contributing to treatment success remain unclear. OBJECTIVE: To identify extent of ablation (EOA) and time to chemotherapy (TTC) as predictors of improved overall and progression-free survival (OS, PFS) and suggest laser parameters to achieve optimal EOA. METHODS: Demographic, clinical, and survival data were collected retrospectively from 20 patients undergoing LITT for newly diagnosed glioblastoma (nGBM). EOA was calculated through magnetic resonance imaging-based volumetric analysis. Kaplan-Meier and multivariate Cox regression were used to examine the relationship between EOA with OS and PFS accounting for covariates (age, isocitrate dehydrogenase-1 (IDH1) mutation, O6-methylguanine-DNA methyltransferase hypermethylation). The effect of laser thermodynamic parameters (power, energy, time) on EOA was identified through linear regression. RESULTS: Median OS and PFS for the entire cohort were 36.2 and 3.5 mo respectively. Patient's with >70% EOA had significantly improved PFS compared to ≤70% EOA (5.2 vs 2.3 mo, P = .01) and trended toward improved OS (36.2 vs 11 mo, P = .07) on univariate and multivariate analysis. Total laser power was a significant predictor for increased EOA when accounting for preoperative lesion volume (P = .001). Chemotherapy within 16 d of surgery significantly predicted improved PFS compared to delaying chemotherapy (9.4 vs 3.1 mo, P = .009). CONCLUSION: Increased EOA was a predictor of improved PFS with evidence of a trend toward improved OS in LITT treatment of nGBM. A strategy favoring higher laser power during tumor ablation may achieve optimal EOA. Early transition to chemotherapy after LITT improves PFS.

Survival benefit of lobectomy for glioblastoma: moving towards radical supramaximal resection.

PURPOSE: Extent of resection remains a paramount prognostic factor for long-term outcomes for glioblastoma. As such, supramaximal resection or anatomic lobectomy have been offered for non-eloquent glioblastoma in an attempt to improve overall survival. Here, we conduct a propensity-matched analysis of patients with non-eloquent glioblastoma who underwent either lobectomy or gross total resection of lesion to investigate the efficacy of supramaximal resection of glioblastoma. METHODS: Patients who underwent initial surgery for gross total resection or lobectomy for non-eloquent glioblastoma at our tertiary care referral center from 2010 to 2019 were included for this propensity-matched survival analysis. Propensity scores were generated with the following covariates: age, location, preoperative KPS, product of perpendicular maximal tumor diameters, and product of perpendicular FLAIR signal diameters. Inverse probability of treatment weighting (IPTW) with generated propensity scores was used to compare progression-free survival and overall survival. RESULTS: Sixty-nine patients were identified who underwent initial resection of glioblastoma for non-eloquent glioblastoma from 2010 to 2019 (GTR = 37, lobectomy = 32). Using IPTW, overall survival (30.7 vs. 14.1 months) and progression-free survival (17.2 vs. 8.1 months were significantly higher in the lobectomy cohort compared to the GTR group (p < 0.001). There was no significant difference in pre-op or post-op KPS or complication rates between the two groups. CONCLUSION: Our propensity-matched study suggests that lobectomy for non-eloquent glioblastoma confers an added survival benefit compared to GTR alone. For patients with non-eloquent glioblastoma, a supramaximal resection by means of an anatomic lobectomy should be considered as a primary surgical treatment in select patients if feasible.

Resection versus biopsy in the treatment of multifocal glioblastoma: a weighted survival analysis.

OBJECT: Diffuse tumor invasion in multifocal/multicentric GBM (mGBM) often foreshadows poor survival outcome. The correlation between extent of resection in gliomas and patient outcome is well described. The objective of this study was to assess the effect of gross total resection compared to biopsy for mGBM on patient overall survival and progression free survival. METHODS: Thirty-four patients with mGBM received either biopsy or resection of their largest enhancing lesion from 2011 to 2019. Relevant demographic, peri-operative, and radiographic data were collected. Tumor burden and extent of resection was assessed through measurement of pre-operative and post-operative contrast-enhancing volume. An adjusted Kaplan-Meier survival analysis was conducted using inverse probability of treatment weighting (IPTW) to account for the covariates of age, number of lesions, satellite tumor volume, total pre-operative tumor volume, degree of spread, and location. RESULTS: Thirty-four patients were identified with sixteen (47.1%) and eighteen (52.9%) patients receiving resection and biopsy respectively. Patients receiving resection exhibited greater median overall survival but not progression free survival compared to biopsy on IPTW analysis (p = 0.026, p = 0.411). Greater than or equal to 85% extent of resection was significantly associated with increased median overall survival (p = 0.016). CONCLUSION: Overall, our study suggests that resection of the largest contrast-enhancing lesion may provide a survival benefit. Our volumetric analysis suggests that a greater degree of resection results in improved survival. Employing IPTW analysis, we sought to control for selection bias in our retrospective analysis. Thus, aggressive surgical treatment of mGBM may offer improved outcomes. Further clinical trials are needed.