A Trial of 5 Fraction Prostate SBRT Versus 5 Fraction Prostate and Pelvic Nodal SBRT

This study will look at the safety of curative radiotherapy to the prostate and lymph glands given in 5 visits, in men with high risk localised prostate cancer. The purpose of the research is to test an advanced type of external beam radiotherapy called stereotactic body radiotherapy (also known as SBRT) in 1128 participants with high risk localised prostate cancer (that is, prostate cancer that has not spread beyond the prostate gland but is at high risk of growing quickly or spreading). Importantly, this treatment delivers a potentially curative dose of radiotherapy in only 5 treatments over two weeks. Half the participants in the trial will receive radiotherapy to the prostate, the other half will have radiotherapy to the prostate as well as the surrounding lymph nodes. The investigators will follow patients in the trial for at least three and half years to see which treatment is best. The investigators will be looking at whether it is safe to give this treatment by reviewing any side-effects that occur and also assessing whether giving SBRT to the lymph nodes as well as the prostate reduces the chance of prostate cancer returning. The treatment will take place at NHS radiotherapy centres that are experienced in giving SBRT and radiotherapy to the pelvic nodes, and have been quality assured to deliver these treatments