To investigate the possibilities to improve Clinical Target Volume (CTV) and Gross Tumour Volume (GTV) delineation by using the latest biological imaging modalities on 15 patients with prostate cancer. Our ultimate goal is to set new GTV and CTV definitions and redefine the choice of irradiation margins in Intensity Modulated RadioTherapy (IMRT) for prostate cancer. Furthermore, try to translate the functional imaging data into a Tomotherapy IMRT plan.