Phase III Study Comparing 2 Brain Conformational Radiotherapy in Combination With Chemotherapy in the Treatment of Glioblastoma

This is a multi-institutional phase III clinical study of interventional type. The trial will include 220 patients with confirmed unifocal glioblastoma over a period of 3 years + 3 years of follow up. Patients with unifocal glioblastoma (diagnosis confirmed by histology on tumoral biopsy or surgical specimen) and who meet all eligibility criteria will be randomized in one chemoradiotherapy arm : * Conventional arm: 3-dimensional conformational radiotherapy + Temozolomide * Experimental arm : simultaneous-integrated boost with intensity-modulated radiotherapy guided by magnetic resonance spectroscopic imaging + Temozolomide The patient monitoring will be regular and standardized. The main objective of this study is to improve overall survival of patients treated in experimental group (with simultaneous integrated boost).