I had the MRIdian Viewray radiation machine. I had looked at Proton therapy and other radiation machines. Many RO's say the outcomes are the same but I don't believe that for a nanosecond if you consider quality of life. Many make recommendations based on their experience with a specific machine or procedure because that is what they are used to. The side effects are certainly related to radiation so margins used by the radiation machine are important. Cornell Weill, in New York City is doing a 1 dose treatment as part of a trial study, on the MRIdian. Try and get backup opinions for everything. Second opinion from an RO outside the local system, Decipher test as a backup to the pathologist report, consider using Spaceoar.., keep coming back to this web site .all helped me feel better on an imperfect decision. I completed my 5 radiation treatments on Valentines day. Flomax preemptively prescribed and after 3 treatments, I took it and it helped restore flow quickly. Good luck.