Stereotactic ablative body radiotherapy (SABR), or stereotactic body radiotherapy (SBRT), is a specialized form of radiotherapy used to treat prostate cancer with five treatments over two weeks, compared with a conventional eight-week or longer treatment course. The purpose of this trial is to investigate the effect that proton-based SABR has on quality-of-life in patients with localized prostate cancer. The evaluation and treatment will otherwise follow standard of care, and is not considered investigational.
Patients undergo evaluation and medical care in the same way that they would if they were not part of this trial. This may include standard of care blood tests (for example, PSA) and scans (for example, MRI). Five SABR treatments will be given with proton beam therapy over two weeks, with up to two treatments each week. Participants will complete a quality-of life questionnaire before starting SABR, at the end of SABR, at three, six and 12 months after SABR, and then yearly.