SURG-11. RISKS AND BENEFITS OF REPEATED RESECTION FOR GLIOBLASTOMA: A SINGLE INSTITUTION REVIEW OF CHARACTERISTICS AND OUTCOMES OF RESECTION OF RECURRENT GLIOBLASTOMA

Abstract Maximal safe resection is standard for newly diagnosed glioblastoma, but for recurrent glioblastoma the value of resection is less clear. We performed a retrospective, single-institution analysis of sequential patients undergoing re-resection for recurrent glioblastoma and analyzed pre-operative risk factors, progression free and overall survival from time of re-resection to death or last follow-up (PFS/OS), and complication rates. Between 2017 and 2022, 38 patients underwent re-resection of glioblastoma (defined by 2016 WHO criteria, 86.8% IDH wild type) and were followed for an average of 157 weeks (range 17-553). The cohort had a mean age of 59.4 years (range 39-87), was 55% male, and included 68.4% MGMT unmethylated tumors. Preoperatively, median Karnofsky Performance Score (KPS) was 80 (range 50-100), and median modified frailty index (mFI-5) was 0 (range 0-4). Re-resection occurred an average of 55.3 weeks after initial resection (SD 59.6, range 5-314), 25.0 weeks after chemotherapy (SD 51.8), and 39.9 weeks after radiation (SD 45.1). Mean OS after re-resection was 67.4 weeks (SD 91.5, range 1-505 weeks), median 59.5 weeks. Average PFS was 24.5 weeks (SD 25.3, range 1-139). The complication rate was 34.2% (n = 15), including 6 patients (15.8%) with a wound infection and 5 (13.1%) with symptomatic hemorrhage. 12 (31.6%) patients had a new neurologic deficit. Postoperative KPS was lower than preoperative KPS (p = .002). Patients with <20 weeks between surgeries, mFI >1, or KPS <80 had higher rates of complications (respectively p = .04, p = .03, p = .03). Patients with mFI >1 or KPS <70 were more likely to die within 30-days of surgery (respectively p = .014; p = .018). Re-resection demonstrated a survival benefit, especially for patients younger than 65 with a mFI of < 2. Though complications were common, post-operative complications were not associated with a shorter overall survival. Consideration for age, frailty, KPS, and timing of surgery may guide selection of patients for re-resection.