Curative Image Guided Radiotherapy for Prostate Cancer

The clinical importance of cone beam computer tomography based image guided radiotherapy (CT- IGRT) has not been established. The primary aim of the present trial is to investigate whether CT- IGRT and consequently reduced safety margins reduces the rectal side effects from curative, high dose radiotherapy in prostate cancer. Any impact of the reduced planning target volume in the CT- IGRT arm on biochemical freedom from disease will be evaluated as secondary outcome. An open randomised phase III trial. The included men will be randomised to receive curative radiotherapy to 78 Gy in 39 fractions with weekly orthogonal position verification and standard safety margins (10-15 mm) or 78 Gy in 39 fractions with daily CT position verification and reduced safety margins (7mm).