SURG-08. A PHASE III RANDOMIZED TRIAL OF GROSS TOTAL RESECTION VERSUS POSSIBLE RESECTION OF FLAIR HYPERINTENSITY LESION ON MR IMAGE FOR NEWLY DIAGNOSED SUPRATENTORIAL GLIOBLASTOMA (JCOG2209)

Abstract BACKGROUND Complete resection of contrast-enhanced lesion (gross total resection: GTR) without severe neurological deficits has been generally accepted as the goal of surgery. However, it remains unclear if additional resection of surrounding FLAIR hyper-intense lesion combined with GTR (FLAIRectomy) has survival advantage of primary glioblastoma patients. Purpose: Multicenter, open-label, randomized phase III trial was commenced to confirm the superiority of FLAIRectomy to GTR alone followed by radiotherapy with concomitant and adjuvant temozolomide in terms of overall survival (OS) for primary glioblastoma IDH-wildtype patients. This trial investigates not only survival but also postoperative neurological and neurocognitive deficits in detail. METHODS We assumed a 2-year OS of 50% in the GTR arm and expected a 15% improvement in the FLAIRectomy arm. A total of 130 patients is required with a one-sided alpha of 5%, power of 70%, and will be accrued from 49 Japanese institutions in 4 years and follow-up will last 2.5 years. Patients 18-75 years of age will be registered and randomly assigned to each arm with 1:1 allocation. The primary endpoint is OS, and the secondary endpoints are progression-free survival, frequency of adverse events, proportion of Karnofsky performance status preservation, proportion of National Institutes of Health stroke scale preservation, proportion of mini-mental state examination preservation and proportion of health-related quality of life preservation. The Japan Clinical Oncology Group Protocol Review Committee approved this study protocol in May 2023. Ethics approval was granted by the National Cancer Center Hospital Certified Review Board. Patient enrollment began in July 2023. DISCUSSION If FLAIRectomy is superior to GTR alone, aggressive surgery will become a standard surgical treatment for glioblastoma with resectable contrast-enhanced lesion. Trial registration: Registry number: jRCT1031230245. Date of registration: 19/July/2023. Date of first participant enrollment: 28/July/2023. Funding for this study is provided by National Cancer Center Research and Development Fund (2023-J-03).