JCOG2209: A phase III randomized trial of gross total resection versus possible resection of FLAIR (Fluid Attenuated Inversion Recovery) hyperintensity lesion on MR image for newly diagnosed supratentorial glioblastoma

INTERVENTION: Group A: Standard treatment group [GTR (complete resection of the contrast‐enhanced lesion) + concomitant chemoradiotherapy with temozolomide] / Group B: Experimental treatment group [FLAIRectomy (complete resection of the contrast‐enhanced lesion and resection of the surrounding FLAIR hyperintense lesion beyond contrast enhanced lesion as much as possible) + concomitant chemoradiotherapy with temozolomide] CONDITION: glioblastoma PRIMARY OUTCOME: Overall survival SECONDARY OUTCOME: Progression‐free survival, Local progression‐free survival, Proportion of adverse events, Proportion of surgical adverse events, Proportion of Karnofsky Performance Status (KPS) preservation, Proportion of National Institute of Health Stroke Scale (NIHSS) preservation, Proportion of Mini Mental Status Examination (MMSE) preservation, Proportion of Health‐related Quality of Life (QOL) preservation INCLUSION CRITERIA: (1) The preoperative cranial contrast‐enhanced MRI satisfies all of the following criteria (a) through (c): (a) The presence of suspected primary glioblastoma. (b) The tumor is located supratentorial (in the cerebrum or diencephalon) and is not found in the cerebellum, brainstem, optic nerves, olfactory nerves, or pituitary gland. (c) There is no evidence of multiple lesions or dissemination. (2) Surgical resection can be performed without worsening the significant neurological symptoms, fulfilling all the following criteria (a) through (c) (a) The predicted resection rate of the contrast‐enhanced lesion is at least 95%. (b) When performing a FLAIRectomy, the predicted resection rate of the FLAIR hyperintense lesion is at least 20%. (c) When performing a GTR (complete resection of the contrast‐enhanced lesion), the predicted resection rate of the FLAIR hyperintense lesion is less than 20%. (3) No prior tumor resection, including biopsy, fo