The PROGRAM-study: Awake Mapping Versus Asleep Mapping Versus No Mapping for Glioblastoma Resections

Inclusion Criteria: 1. Age ≥18 years and ≤ 90 years 2. Tumor diagnosed as GBM on MRI as assessed by the neurosurgeon 3. Tumors situated in or near eloquent areas; motor cortex, sensory cortex, subcortical pyramidal tract, speech areas or visual areas as indicated on MRI (Sawaya Grading II and II) 4. The tumor is suitable for resection (according to neurosurgeon) 5. Written informed consent Exclusion Criteria: 1. Tumors of the cerebellum, brain stem or midline 2. Multifocal contrast enhancing lesions 3. Medical reasons precluding MRI (e.g. pacemaker) 4. Inability to give written informed consent (e.g. because of severe language barrier) 5. Second primary malignancy within the past 5 years with the exception of adequately treated in situ carcinoma of any organ or basal cell carcinoma of the skin