Local Ablative Radiotherapy for OLIgoprogressive Castration Resistant Prostate Cancer

This is a multicentric, randomized, prospective Phase II intervention trial. Efficacy is measured as the rate in patients with PSA progression one year after randomization (defined as PSA nadir after randomization +2 ng/ml). There is a 2:1 randomization between intervention and observation group. Patients with PSA progression in the observation group are offered a new diagnosis. This should preferably correspond to the initial diagnosis. Therapy is performed for all patients in the intervention arm using high dose radiation therapy, either as conventional fractional irradiation with 2 Gy/fraction up to a total dose of 50 Gy or as hypofractional irradiation with a single dose of 10 Gy up to a total dose of 30 Gy. The decision as to which regimen the patient is to be treated according to is made by the treating physician, taking into account in particular the location of the volume to be irradiated in relation to the organs at risk and any previous irradiation.