I had my prostrate cancer treated at Houston MD Anderson with Proton therapy 7 years ago. No side effects besides a sunburn on my hips. Just had my PSA of .2 for the 7th year and a colonoscopy is clear except for diverticulitis and a prolapsed hemorrhoid. My brother had radiation at a clinic and died 2 years ago with bone and lung cancer. He had to wear diapers for bowel and urinary incontinence. Proton therapy is hands down the right choice if you can make that choice. They will tell you if the cancer has spread it's less effective, but I saw a man that had throat cancer that had spread to his chest that got treated with proton and normal radiation and chemo. He's still alive 7 years later and didn't lose his jaw as the "Experts" predicted back in Alabama. Proton therapy is used for much more than just prostate cancer. Children with brain tumors, leg and arm tumors, kidneys, livers, and more might be available for treatment.
I will say this,....my doctor was Dr.Lee, who actually wrote the software for the machine. He was a pioneer for Proton Therapy. He has since moved to Dallas and my doctor now, I don't even know. I don't want to speak ill of anyone, but losing Dr Lee was a big loss for the Houston program IMO. Still, Proton Therapy has to be the number one choice for anyone who can get it.
Six years ago I was treated for prostate cancer with proton radiation therapy. Treatment was very easy, almost benign. Worse effect for me was gas and loose stools, Gas X pretty much took care of that. When last I saw my doctor I asked him what the status of my cancer was. He said, that by any measure, I was cured as cured can be. His words. I give thanks to the Lord that this treatment is available.