Repeat Resection for Recurrent Glioblastoma in the WHO 2021 Era: A Longitudinal Matched Case-Control Study

Background and Objectives: This study aims to evaluate the overall survival benefits of repeat resection in patients with recurrent glio-blastoma, IDH-wild type (rGBM) and to identify factors for long-term survival, including the role of clinical, radiological, and molecular parameters. Methods: This longitudinal matched case-control study included 60 patients with rGBM divided into two groups: one-surgery (n=30) and repeat resection (n=30). Baseline characteristics, preoperative and postoperative volumes, and molecular markers were assessed. Survival analyses were conducted using the Log-Rank test, and associated factors with long-term survival were identified in the repeat resection cohort. Results: Patients who underwent repeat resection had a significantly longer median survival of 23.9 months compared to 9.2 months in the one-surgery group (p < 0.001). Preoperative tumor volume was found to correlate with postoperative residual volume in repeat resections. Patients with no residual contrast-enhancing tumor vol-ume (0 cm³) after repeat resection had a mean survival of 25.0 months, while those with any residual volume had a mean survival of 9.4 months. Lower KPS (≤70) and GCS (≤13) scores were significantly associated with short-term survival, highlighting the importance of functional status at the time of repeat resection. Conclusion: Complete repeat resection may improve overall survival in patients with recurrent IDH-wildtype GBM and should be considered a therapeutic option rather than a diagnostic or salvage procedure. Early surgical inter-vention, before declines in KPS and GCS or tumor volumes become unmanageable, may lead to better out-comes. Further studies with larger cohorts are needed to confirm these findings.