This prospective multicenter non-interventional study (NIS) aims at confirming the survival benefit of Optune Gio® - in terms of OS and PFS - and describing device usage (compliance will be measured through patient's usage report, recorded by each device) and impact on QoL, in a real-life setting in France, in a large cohort of participants with newly diagnosed GBM who completed radiotherapy and concomitant TMZ after surgery and initiatingtreatment with Optune Gio® device together with maintenance TMZ. A special emphasis will be given to the evaluation of QoL and the impact of Optune Gio® on daily life, considering the limited life expectancy of these patients, the symptom burden and significant disease-related disability.