I finished my 5 mridian linac built in MRI and narrow margin radiation in February 2023. Someplaces are still using the machine but the manufacturer, Viewray, is no longer around. Margins are important. The narrower the mapping around the prostate, the less healthy tissue gets exposed and the fewer the side effects. My margins were 2 mm but most radiation machines are 3-6 mm. You might also want to consider Elekta.com: MRI/Radiation machine combination unit which is Similar to the Mridian or Mevian.com: Proton therapy radiation machine manufacturer. I had spaceoar to separate the prostate from the rectum to reduce healthy tissue exposure as well. The FDA last year approved BioProtect which is supposed to protect an even larger area.

I used Flomax after the 3rd session to help open up the urination flow. No other radiation symptoms for me.