See this related discussion:
- Starting Proton Treatments for Prostate Cancer: Any experiences? https://connect.mayoclinic.org/discussion/starting-proton-treatments/

I had proton treatment for rectal cancer five years ago. It was Scripps then, now California Proton. I'd done research for a friend and know upon diagnosis that I would have Proton. In my case I was avoiding chemotherapy. The diagnosing physician was upset enough to say, "Don't you dare." Dauntless, I flew to University of Pennyslvania where they refused to treat without chemo. I few more trips around and I ended up in San Diego. Dr. Giap ( he is in Florida now) agreed. The following week, I had testing, tatoo markers and the week after began a six month course. I am five years clear, so considered cured.
The treatment itself was painless. I'd spend 30 minutes at the clinic. The actual positioning, summoning of the beam and the radiation was maybe ten minutes of the thirty.
It was easier than any treatment I've every heard of. All of the md's, except at CA Proton told me I was doing the wrong thing.
If you haven't had genetic testing of the tumor itself, somatic testing, you might consider having that done, even if you have to fight for it.
Wishing you the best luck. If there is anything more you think I might know, I'm happy to talk about it. It was a good experience from beginning to end.

popkovas, you are going to get a lot of replies on this. I had proton therapy at UFPTI. Mine was 30 treatments (5 days a week for 6 weeks). The treatment itself is a peace of cake. Probably 10 minutes on table getting treated and rest of time is just prep to make sure all is calibrated.

It is the prior testing and procedures like Space/Oar and markers that can be tacking only because they take time to do.

I was not offered the 5 treatment option but the pencil beam. They mentioned I could have done a different type but I have an ICD/Pacemaker and their physics department wanted to keep the radiation as much as possible restricted to not interfere with ICD/Pacemaker.

I think going with proton is a personal decision but try to use a well known and experienced facility. The cure rates of both proton and photon are the same. It is the factor that proton radiation had very little radiation going in and not going past prostrate where photon continues through and out the body.