Repeat resection for recurrent glioblastoma – Does timing matter?

Background The optimal timing of repeat surgical resection in patients with recurrent IDH-wildtype glioblastoma (rGB) remains unclear. We aimed to characterize temporal patterns between radiological suspicion of recurrence and repeat resection and to evaluate the impact of early versus delayed surgery on the extent of resection (EOR), functional outcomes, adjuvant therapy, and survival. Methods We retrospectively analyzed a consecutive cohort of 150 patients who underwent resection for histopathologically confirmed rGB between 2015 and 2023 at a single tertiary care center. All patients had available pre- and early postoperative MRI and underwent surgery under intraoperative MRI guidance. Assessment of contrast-enhancing preoperative and residual tumor volumes (RTV) was performed using semi-automated segmentation. Based on the mean time between suspicion of recurrence and repeat resection (54 days), patients were stratified into early (≤ 54 days) and late (> 54 days) surgery. EOR was classified according to RANO Resect criteria and a 0.175-ml RTV threshold. Functional outcomes, postoperative treatment, as well as progression-free survival (PFS), and overall survival (OS) after repeat resection were compared between groups. Results Median time from suspicion of recurrence to repeat resection was 18 days, with 75% of patients undergoing reoperation within 6 weeks. Early (n = 120) and late (n = 30) surgery groups showed comparable baseline demographics, performance status, tumor eloquence, and preoperative neurological deficits. Preoperative tumor volumes were significantly smaller in the early surgery group (12.7 vs. 25.9 ml, p = 0.002). Late surgery was associated with a trend toward higher RTV and lower rates of gross total resection, though without statistical significance. Rates of transient and permanent postoperative neurological deficits were low (15% and 2%) and did not differ between groups. Adjuvant treatment patterns differed, with early surgery patients more frequently receiving CCNU-based chemotherapy, while late surgery patients more often received no further treatment. Median OS (14.3 vs. 12.4 months) and PFS (4 months in both groups) after repeat resection were not significantly different between early and late surgery groups. Conclusion Most repeat resections for rGB are performed shortly after radiological suspicion of recurrence. While delayed surgery is associated with larger tumor volumes and a trend toward less favorable EOR and adjuvant treatment options, timing of surgery alone was not independently associated with functional outcomes or survival. These findings support individualized decision-making for repeat resection based on clinical and radiological factors rather than timing alone.