This research project includes 3 steps : first the investigators will establish the 18F-FMISO production technique for clinical application at CYCERON PET center. The second step consists in the preclinical validation of 18F-FMISO as a hypoxic marker and as a powerful tool for evaluating the therapeutical efficiency of anti-angiogenic treatment (sutent) in experimental rat gliomas. The third step is the clinical trial HypOnco. This research proposal aims to develop and use non invasive imaging methods (18F-FMISO with PET) and biological methods (after surgical resection) to detect hypoxic (HIF1 and HIF2) and angiogenic (VEGF and EPO) regions in different malignant gliomas with different degrees of vascularization (15 patients with grade III gliomas and 15 patients with grade IV glioblastomas). Within the same patient 18F-FMISO as a hypoxic index will be performed. A magnetic resonance imaging examination (MRI) including perfusion sequences and MR spectroscopy will also be assessed for each patient. Following this imaging protocol, surgical resection will be performed allowing us to study expression of endogenous factors induced by hypoxia and angiogenic factors by real time RT-PCR and in immunohistochemistry.