ACT-15 EFFICACY AND SAFETY OF SUBTOTAL RESECTION, 'FLAIRECTOMY' FOR RECURRENT GLIOBLASTOMA

Background Aggressive resection of recurrent glioblastoma has been reported to prolong survival and should be considered for resectable recurrences. In recent years, expanded resection for primary glioblastoma, especially removal of the FLAIR hyperintensity region beyond the contrast-enhancing lesion (FLAIRectomy; FR), has been reported, but there are no reports of FR for recurrent glioblastomas. In this study, we examined the efficacy and safety of FR for recurrent glioblastoma. Methods Recurrent glioblastoma operated on at our institution from January 2014 to July 2022 were included. The extent of resection (EOR) of contrast-enhancing lesions and FLAIR hyperintensity lesion was measured. Progression-free survival (PFS), overall survival (OS), surgical morbidity, KPS, and MMSE were analyzed retrospectively. Removal of at least 20% of the FLAIR hyperintensity lesion was defined as FR. Results Thirty-five surgeries in 28 patients (age at surgery 15-81 years; median 54 years, male 20/female 15) were included. The EOR of the contrast-enhancing lesion was 96.6± 7.4%, with GTR in 28 cases and non-GTR in 7. The EOR of the lesion with FLAIR hyperintensity was 33.2±36.5% and FR was achieved in 15 cases (42.9%). The median preoperative KPS was 90 (50-100; mean 83.3 ) in the FR group and 80 (60-100; mean 81) in the non-FR group. Both PFS and OS from surgery at recurrence were significantly prolonged in the FR group (median PFS; 8.1 months vs. 4.6 months, p=0.032, median OS; 36.1 months vs. 15.9 months, p=0.009); there was no difference in PFS or OS between the GTR and non-GTR groups (p=0.33, 0.79). There were significantly fewer patients in the FR group having a decrease in KPS of 20 or more at 30/90 days postoperatively (p=0.037, 0.020). Conclusion In our retrospective analysis, FR prolongs PFS and OS without decreasing KPS for resectable recurrent glioblastoma. Further validation in prospective studies is warranted.