The purpose of the diet is to shrink the rectum so it is less of a target for stray radiation, so I think it would be helpful for any type of radiation.

I’m going to add my two cents here, I’ve had prostate cancer for 13 years and so I am experienced. My diet has drifted away from red meats or processed meats and consist of mostly vegetables, chicken, fish, eggs, etc. plus minerals and vitamins and larger doses. Plus prayer. my first time through radiation, 44 days, I was simply tired all the time and it took about two months to get my energy level back. The third time through radiation I had much larger doses and it’s going to take three or four months to get my energy level back . Plus, I’m on apaulutime (?). A unspoken side effect of Zytiga and Ebearla is that your body stores belly fat. So be careful and eat your vegetables.