This trial investigates safety and feasibility of a hypofractionated radiotherapy (i.e. with higher daily doses and shorter total treatment time compared to standard fractionation) of the prostate bed with or without the pelvic lymph nodes.

While evidence on safety and efficacy of primary hypofractionated radiotherapy in prostate cancer is accumulating, data on postoperative hypofractionated treatment of the prostate bed and of the pelvic lymph nodes is still scarce. This phase II trial was initiated to investigate safety and feasibility of hypofractionated treatment of the prostate bed alone or with the pelvic lymph nodes.

A total of 80 prostate cancer patients with the indication for adjuvant radiotherapy will be enrolled, where 40 patients with a low risk of lymph node involvement (arm 1) and another 40 patients with a high risk of lymph node involvement (arm 2) will each receive 54 Gy in 18 fractions to the prostate bed. Arm 2 will be given 45 Gy to the pelvic lymph nodes additionally. Helical Tomotherapy and daily image guidance wil be used.

Inclusion Criteria:

• resected prostate carcinoma with histological grading (Gleason Score)
• status post prostatectomy for a pT3 carcinoma and/or R1/2 resection or PSA recurrence after prostatectomy (2 consecutive PSA rises)
• PSA recurrence ≥ 1 ng/ml: CT/PET/MRI imaging excluding pathological lymph nodes
• Karnofksy performance score ≥ 70 %
• age 18 - 80 years
• only arm 2: antihormonal therapy for 2 months prior to radiotherapy and continuation of hormonal suppression after radiotherapy recommended
• written informed consent

Exclusion Criteria:

• patient's refusal
• patient's inabillity to give informed consent
• stage IV (distant metastases)
• lymph node involvement outside the pelvis
• severe wound complications after laparatomy
• only arm 2: severe lymphoedema of the legs, elephantiasis, postthrombotic syndrome
• decompensated pulmonary, cardiovascular, metabolic, hematopoetic, coagulatory or renal comorbidities
• known other malignant disease with distant metastases
• prior pelvic irradiation
• participation in another clinical trial that might compromise the results of the PRIAMOS trial or the other trial