The study was extremely poorly recruiting due to several reasons, which include delayed referral of patients to RT after surgery and different practices regarding adjuvant treatment of high risk prostate cancer patients. Among these recent developments of prostate cancer treatment the most important are considered utilization of early salvage treatment concept, increased utilization of sensitive PSA tests and higher RT doses and modern RT technologies. The changes proposed in the amendment are expected to enhance recruitment and enable the combined analysis with the ongoing RADICALS study. This was considered a scientific amendement (the proposed changes add a new stratum in the study and enlarge the patient eligibility criteria). The major scientific changes proposed: •Increase the time interval between surgery and the start of RT to maximum 26 weeks for the stratum “immediate post-operative adjuvant setting”. •Add a new stratum for patients treated in the “early post-operative salvage setting” i.e. upon post-operative PSA failure. Post-operative PSA failure was defined as either 2 consecutive increases of the PSA level and final PSA value >0.1 ng/ml and ≤0.5ng/ml or, in the case where the third PSA value is not >0.1ng/ml, by 3 consecutive rises of the PSA and a final PSA value ≤0.5ng/ml. •Allow cN0 patients with negative staging examinations (either CT or MRI of pelvis and abdomen) to be included in the protocol. •Increase pre-operative PSA upper limit from 20ng/ml (5xULN) to 30ng/ml. •Relax the requirements on the radiotherapy dose schedule. The sites will opt for their preferred RT regimen for each setting in a range of doses specified for each setting (between 64-70 Gy). Higher doses may also be acceptable pending feasibility, upfront dummy run and QART approval. •To better capture biochemical failure after protocol treatment, intermediate PSA values will be recorde between the visits (PSA to be taken every 3 months for up to 5 years and then every 6 months).