Spot-Scanning Based Hypofractionated Proton Therapy for Low and Intermediate Risk Prostate Cancer

The purpose of this study is to assess the effectiveness and safety of spot-scanning based hypofractionated proton radiotherapy for the treatment of intermediate and low risk prostate cancer. The treatment effectiveness is defined as freedom from biochemical failure. Treatment safety will be documented with acute and late morbidity assessments. Dose volume relationships for late side effects in organs at risk surrounding the prostate will be calculated from the dose volume histogram parameters assessed during treatment planning. Patient assessed Quality of life data including sexual function will be collected to increase our understanding how the reduction of normal tissue irradiation with proton therapy with subsequent decrease in functional impairments will overall affect the patient's life.