Assessment of the RANO-resect criteria in elderly patients with glioblastoma.

Introduction: Elderly patients with IDH-wild type glioblastoma (IDH-WT GBM) have a dismal prognosis compared to younger patients. Given the prognostic relevance of extent of resection (EOR), we aimed to assess the prognostic utility of the Response Assessment in Neuro-Oncology (RANO)-resect classification in this population.

Methods: We retrospectively analyzed patients ≥ 65 years who underwent resection for newly diagnosed IDH-WT GBM between 2005 and 2023. EOR was categorized per RANO-resect classifications based on volumetric MRI analysis.

Results: Among 147 patients, 54 (36.7%) had Class 1 and 2 resection, 70 (47.6%) had Class 3 resection, and 23 (15.6%) underwent biopsy. The incidence of postoperative neurological and non-neurological complications was comparable across RANO-resect classes. Median overall survival (OS) was significantly longer for Class 1 and 2 resection (16.0 months, 95% CI: 10.4-21.7) versus Class 3 (10.6 months, 95% CI: 9.1-12.1) and biopsy (8.8 months, 95% CI: 4.0-13.5) (p = 0.033). Progression-free survival (PFS) did not differ between groups. Notably, in the adjuvant chemoradiotherapy sensitivity analysis, categorical RANO-resect classes showed no OS differences, but residual CE tumor volume remained independently prognostic of OS (HR = 1.006; 95% CI: 1.001-1.010; p = 0.010).

Conclusion: While greater EOR within RANO-resect classes correlated with improved OS and similar safety, adjuvant chemoradiotherapy sensitivity analyses showed no categorical OS differences. However, residual CE tumor volume remained independently prognostic of survival. Further studies are needed to clarify the role of surgery in elderly IDH-WT GBM patients.