Preference-based Comparative Study on Definitive Radiotherapy of Prostate Cancer With Protons

The hypothesis of the study is a 7.5% decrease of combined genito-urinary and intestinal side effects from 15% with photon therapy to 7.5% by the use of protons. With an alpha of 0.05 and 80% power it is therefore necessary to treat 131 patients with protons to detect such difference. With an estimated drop-out rate of 10% 146 patients have to be recruited to the proton arm. As randomization to photon or proton therapy is not possible in a multicenter setting with only few proton facilities available patients treated with photons will be prospectively matched to their proton counterparts. Stratification criteria will include: Age, high dose volume, androgen deprivation, history of surgery, obstructive disease, increased risk for rectal bleeding, socio-economic criteria and use of rectal balloon during radiotherapy. Comparison of the primary endpoint will be restricted to patients without irradiation of lymphatic drainage.

Inclusion criteria

• life expectancy ≥ 10 years
• adenocarcinoma of the prostate confirmed by punch biopsy
• locally limited to locally advanced adenocarcinomas without evidence of distant metastases i.e. T1-3b N0-1 M0
• stage-related indicated neoadjuvant / adjuvant androgen deprivation possible (neoadjuvant ≤ 6 months)
• good general condition (ECOG performance status 0 - 1)
• marker seed implantation before irradiation (optional) or possibility of Image-guided Radiation Therapy (IGRT) by CT
• adequate compliance for follow-up
• written informed consent

Exclusion criteria

• distant metastases
• previous radiotherapy of the lesser pelvis
• previous or concomitant other malignant disease except when there is no impact on treatment or follow-up of the prostate cancer
• participation in another clinical study, if it's excluded by the study protocols