Avall, having to make that exact choice, we decided on City of Hope. Dr. Rossi doesn't think the five is a good choice. The difference would have been 28 treatments for a total of 58GY with a spacebar procedure. City of Hope is 5 treatments for a total of 40GY. The treatments are every other day so MWF and then TTh.
City of Hope is so much easier, but the genuine advantage is in the 2mm margin that they radiate around the prostate. With proton it is 3mm.
Opinions about the effectiveness of the total amount of radiation don't have enough evidence either way. Rossi suggests that 8GY a day could be more damaging in the final anaylsis. Damage from radiation treatment is sometimes not apparent for several years after treatment.
I drive 258 miles to the Lennar City of Hope Cancer Center, but would drive the extra 55. It's the MRI guidance during treatment and the lower GY total that were convincing.
If you haven't spoken with Rossi, you might want to have a zoom appointment. He has the most extensive experience. And there may be a deciding factor in the specifics of your cancer.
Ten minutes.
Best luck with your choice. I'm guessing you be at City of Hope.