Each person takes it differently, but there are several side effects that most tend to have. I had radiation 24 years ago, I took it like drinking koolaid, no problem, very little problem. Worked every day, didn't miss a lick. 24 years later, I was older 48, and it kicked my butt, I had the droopsies at about 2 each day after two weeks of treatment. I was getting treated in the neck area, and got burned fairly good in that area. I had sores in my mouth, couldn't eat much, lost 50#, need to start eating everything you can find right now. I lost my voice for 30 days, it came back raspy. So, this time was worse on me than last time. I suspect since you are dealing with prostate, you will not have the same issues with voice, sores in mouth etc. since you will be treated in a different area. Probably still be droopy and need a nap.
Someone who has had prostate treatment will be able to answer soon, all in all, it's not near as bad as chemo, and I would take it two to one today over chemo.
Best of luck to you!