Influence of Surgical Resection on Survival in Glioblastoma with Multiple Localizations—a Multi-Center Retrospective Analysis

INTRODUCTION: The presence of multiple localizations in glioblastoma is rare and associated with poor prognosis. The presence of a visible junction between enhancing lesions on magnetic resonance imaging (MRI) is defined as multifocal (MF), the absence of a dissemination pathway as multicentric (MC). METHODS: Data collection was performed as a multicenter retrospective analysis. From Jan 1, 2008, to Dec 31, 2020 patients presenting with IDH wild-type glioblastoma (CNS WHO grade 4) with multiple localizations were included. Demographic data, tumor size, Karnofsky Performance Score (KPS) before and after surgery were analyzed. EOR was measured by FLAIR and contrast-enhanced MRI. Gross total resection (GTR, residual tumor (RTM) < 5%), subtotal resection (STR, RTM < 30%), partial resection (PR, RTM > 30%), and biopsy (RTM > 75%). RESULTS: This study included 117 patients with a median age of 62 years. 45 (38.5%) patients had MC lesions, 72 (61.5%) MF. Median KPS on admission was similar in both subtypes. Median OS did not differ among MC and MF glioblastomas. In MF glioblastoma, GTR (p = 0.0001) and STR (p = 0.0001) significantly increased the median OS compared to PR and biopsy. Likewise, OS was increased after GTR (p = 0.0272) and STR (p = 0.0272) in MC glioblastoma, as well. Overall, resection significantly increased OS in patients with glioblastoma with multiple localizations compared to biopsy alone. In multivariate logistic regression analysis EOR and chemotherapy were significant and independent predictors of OS in MC and MF glioblastomas. CONCLUSIONS: These data indicate that GTR and STR positively affects OS in patients with MC and MF glioblastoma. These results argue for a more aggressive stance towards surgical treatment of these tumors with particularly poor prognosis, even when GTR is not within reach before resection.