By introducing a BTV within the GTV a non-uniform CTV delineation can be used and thus margins can be minimised. This allows further escalation of the dose. Setup inaccuracy and organ movement further determine the irradiation margins needed. Therefore, controlling day to day position variability together with the delivery of optimised conformal irradiation will be the next goals to set. Helical Tomotherapy is a novel approach to the delivery of radiation for cancer treatment, which will be able to do both. It relies on a 6 MV linear accelerator for treatment purposes and a 3.5 MV-CT scan for imaging purposes. Both are mounted on a ring gantry that rotates around the patient as he advances through the ring. A 64-leaf collimator defines the radiation fan beam. In a theoretical study Helical Tomotherapy plans required minimal operator interaction and resulted in excellent sparing of normal structures in prostate IMRT. Therefore, in this study we also propose to fuse the anatomic an biologic imaging data with a Tomotherapy MV-CT and make a inverse IMRT Tomotherapy plan. This planning exercise will precede a feasibility study on functional imaging and individualised day to day adapted radiotherapy by Tomotherapy.