I am 65 years old. PSA pre-treatment ranged from 8.9 to 12. The SpaceOAR seems to be standard at Mayo. Injection was not painful and was done at same time as fiducial marker implantation. Proton Beam instrument was Hitachi manufactured. Amazing eequipment and hopefully results will be long lasting. It can take 44 months for PSA to reach new nadir.
Best wishes for excellent results.

I am a 74 year old who just finished the 5 proton radiation treatment at Mayo Phoenix. My lesion was 7mm and my PSA was 2.9. I had 5 cores positive out of 30. The reason for 30 is my prostate is 120 gms. The 5 positive cores were all from the area of the lesion and I had a transperineal fusion biopsy under a local. The only side effects I have noticed came after the 2nd radiation treatment. I had my coffee mug waiting in the car after my first treatment and finished it and the rest of the pot when I got home. I did the same after the 2nd even though everything I read said to avoid caffeine. About and hour later my bladder said "you fool you should have listened to the instructions". My bladder had me going about every 15 minutes for most of the day. The only other effect was a slight pinkish discharge before my morning bowel movement for about three days 5 days after treatment ended. I felt guilty ringing the bell after it was done because it was so easy. I even messaged the radiation oncologist last week to ask if he was sure that they gave me enough radiation.