@ngershon
I had the MRIdian linac machine, 2 mm margins instead of 3-5 mm for other radiation machines and I had 5 treatments. I believe the MRIdian or the Elekta, are superior radiation machines because they have built in MRI as part of the machine and don’t use fused images so what they see live is what they treat, plus the lower margins mean less exposure and side effects.

I had spaceoar as it gives a bit more separation between the rectum and the prostate. All five of the radiation oncologists I spoke with were for it. Again, less exposure affects side effects.