Usefulness of Therapy Monitoring by Means of [(18)F]Fluoroethyltyrosine-Positron Emission Tomography (FET-PET) in Glioblastoma Multiforme Patients

Inclusion Criteria: * neuroradiologically suspected Glioblastoma multiforme * histological verification will be obtained either by microsurgery or by stereotactic biopsy. The neuropathological diagnosis will be verified by a reference neuropathologist * patients will undergo radiochemotherapy subsequent to surgical procedure * patients older than 18 years * Karnofsky Performance Score \>=70 * pregnant or nursing female patients will not be included in this study * safe contraceptive methods during the radiochemotherapy and chemotherapy Exclusion Criteria: * patients in whom informed consent cannot be obtained due to organic brain syndrome or insufficient language skills * patients who cannot lie quiet for a time period of app. two hours during the FET-PEt scan * medical history of a metastatic brain disease * patients in whom an MRI scan cannot be performed due to claustrophobia metallic protheses or pacemakers etc.