The efficacy and safety of sublobectomy for glioblastoma: a propensity score–weighted study

OBJECTIVE: Sublobectomy is a modified surgical paradigm based on anatomical lobectomy, incorporating functional boundaries to extend resection safely, particularly for glioblastoma, a highly aggressive brain tumor. This study aimed to evaluate the efficacy and safety of sublobectomy and its prognostic value within the Response Assessment in Neuro-Oncology (RANO) categories for extent of resection. METHODS: Building on their clinical practice, the authors established a sublobectomy standard defined by lobe-specific anatomical boundaries complemented by functional mapping limits and applied it across the frontal, temporal, parietal, and occipital lobes. In this retrospective single-center study, 989 IDH-wildtype glioblastoma cases were analyzed, and 401 met the anatomical criteria for sublobectomy. After excluding cases with residual contrast-enhancing (CE) tumor or incomplete postoperative chemoradiotherapy, 331 cases were included. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to minimize confounding biases. Survival outcomes were assessed using Kaplan-Meier survival analysis and Cox proportional hazards models, while functional outcomes were evaluated using Karnofsky Performance Status, Boston Diagnostic Aphasia Examination, and Eastern Cooperative Oncology Group scores. RESULTS: Sublobectomy significantly improved overall survival (OS) and progression-free survival (PFS) compared to CE tumor resection (median OS: 25.6 vs 18.1 months [p < 0.001], median PFS: 17.0 vs 12.0 months [p < 0.001]). These findings remained consistent after IPTW and PSM analyses. Functional assessments showed no additional risks to quality of life, physical performance, or language function. In RANO class 1 patients, sublobectomy also significantly improved OS and PFS. Subgroup analyses revealed greater survival benefits in patients with TERTp mutations or MGMTp methylation. Maximal safe edema resection emerged as a key factor for improved outcomes. CONCLUSIONS: Sublobectomy is a functionally optimized supramaximal resection strategy with favorable safety and significant survival benefits for glioblastoma patients.