Validation of Preoperative Neoadjuvant Bevacizumab Therapy for Newly Diagnosed Glioblastoma via Comparative Analyses with Propensity Score Matching

BACKGROUND/OBJECTIVES: The role of preoperative neoadjuvant bevacizumab (neoBev) in newly diagnosed glioblastoma (GB) remains controversial. We evaluated its impact on perioperative and survival outcomes and explored imaging-based associations with prognosis. METHODS: We retrospectively analyzed 33 patients with newly diagnosed GB who received preoperative neoBev (10 mg/kg; surgery performed 21-30 days later). A matched control cohort of 33 patients treated with standard chemoradiotherapy was selected using propensity score matching. Changes in Karnofsky Performance Status (KPS), extent of resection, and volumetric alterations on gadolinium-enhanced T1-weighted MRI (T1Gd) and FLAIR were assessed. Progression-free survival (PFS) and overall survival (OS) were compared. RESULTS: All patients had GB (31 IDH-wild-type, 2 IDH-mutant). Median KPS improved after neoBev (71 to 83), while no improvement was observed in controls. After matching, median PFS and OS did not differ between the neoBev and control groups (7.4 vs. 8.6 months and 13.4 vs. 13.8 months, respectively). Exploratory analyses in the neoBev cohort showed that greater T1Gd volume reduction was associated with improved PFS and OS, whereas FLAIR changes were not. CONCLUSIONS: Preoperative neoBev did not improve survival compared with standard chemoradiotherapy. However, it was associated with improved functional status, and exploratory imaging findings suggested associations between early radiographic response and outcome. NeoBev should not be used routinely but may have a contextual role in selected patients with perioperative challenges.