TTFields General Routine Clinical Care in ndGBM Patients: a French Prospective Non-Interventional Study (TIGER France)

Inclusion Criteria: * Participant aged ≥ 18 years old. * Participant with newly diagnosed GBM. * Participant who completed radiochemotherapy after surgery or biopsy. * Participant within first 2 cycles of maintenance TMZ. * Participant for whom the physician has decided to initiate treatment with Optune® according to Instruction For Use or medical guidelines. Exclusion Criteria: * Participant currently participating in a prospective clinical trial studying a different treatment than the one studied in this current prospective study. * Patient currently breastfeeding. * Patient who is pregnant, thinks she might be pregnant or is trying to become pregnant. Patient of childbearing potential must use a contraceptive method for the whole duration of their participation in the study. * Patient suffering from a significant neurological disease (primary epilepsy, dementia, progressive degenerative neurological disorder, meningitis or encephalitis, hydrocephalus associated with increased intracranial pressure). * Patient with a known sensitivity to conductive hydrogels, such as gel used with electrocardiogram (ECG) or transcutaneous electrical nerve stimulation (TENS) electrodes. * Patient with an active implanted medical device, a cranial defect (such as a missing bone that has not been replaced) or bullet fragments. Active electronic devices include, for example, deep brain stimulators, spinal cord stimulators, vagus nerve stimulators, pacemakers and defibrillators. * Participant being deprived of liberty by a judicial or administrative decision, or who is under a measure of legal protection (e.g. guardianship or curatorship).