Perilesional Resection of Glioblastoma Is Independently Associated With Improved Outcomes.

BACKGROUND: Resection is a critical component in the initial treatment of glioblastoma (GBM). Often GBMs are resected using an intralesional method. Circumferential perilesional resection of GBMs has been described, but with limited data. OBJECTIVE: To conduct an observational retrospective analysis to test whether perilesional resection produced a greater extent of resection. METHODS: We identified all patients with newly diagnosed GBM who underwent resection at our institution from June 1, 1993 to December 31, 2015. Demographics, presenting symptoms, intraoperative data, method of resection (perilesional or intralesional), volumetric imaging data, and postoperative outcomes were obtained. Complete resection (CR) was defined as 100% resection of all contrast-enhancing disease. Univariate analyses employed analysis of variance (ANOVA) and Fisher's exact test. Multivariate analyses used propensity score-weighted multivariate logistic regression. RESULTS: Newly diagnosed GBMs were resected in 1204 patients, 436 tumors (36%) perilesionally and 766 (64%) intralesionally. Radiographic CR was achieved in 69% of cases. Multivariate analysis demonstrated that perilesional tumor resection was associated with a significantly higher rate of CR than intralesional resection (81% vs 62%, multivariate odds ratio = 2.5, 95% confidence interval: 1.8-3.4, P < .001). Among tumors in eloquent cortex, multivariate analysis showed that patients who underwent perilesional resection had a higher rate of CR (79% vs 58%, respectively, P < .001) and a lower rate of neurological complications (11% vs 20%, respectively, P = .018) than those who underwent intralesional resection. CONCLUSION: Circumferential perilesional resection of GBM is associated with significantly higher rates of CR and lower rates of neurological complications than intralesional resection, even for tumors arising in eloquent locations. Perilesional resection, when feasible, should be considered as a preferred option.