P27.21.A RE-RESECTION FOR RECURRENT GLIOBLASTOMA - DOES TIMING MATTER?

Abstract BACKGROUND Surgery for recurrent glioblastoma (GBM) has the potential of prolonging patient survival. However, the impact of the timepoint of re-resection after tumor suspicion on post-surgical survival and neurological deterioration remains unclear. MATERIAL AND METHODS Patients undergoing first re-resection for recurrent WHO grade 4 IDH-wildtype GBM were analyzed retrospectively. Post-surgical neurological deterioration and post-surgical survival of patients undergoing early surgery (within 3 weeks) after suspected recurrence were compared to those receiving surgery later than 3 weeks. In addition, volumetric analyses were used to determine tumor burden and location. RESULTS 103 consecutive patients (mean age: 59 years; 64 males and 39 females) undergoing first re-resection for recurrent GBM from 2018 to 2022 were included. Gross total resection (GTR) had been achieved in 93 patients (91%) at first diagnosis and was achieved in 96 patients (93%) at repeat surgery. Intraoperative MRI-guided resection was performed in 84 (82%) cases and 5-ALA was applied in 8 (8%) cases, with neuromonitoring utilized in 14 (14%) cases. The median time interval between first and second resection was 341 days (IQR 343 days) while the median time interval between suspected tumor recurrence and re-resection was 20 days (IQR 23 days). Surgery was delayed beyond 3 weeks after suspected recurrence in 49 cases (mean interval 11 in the ‘early’ vs 187 days in the ‘late’ group, p