Not a bit. Proton radiation hits only the target cells. I was told that, during radiation, I might feel some swallowing issues, but I didn't!! After 16 treatments, I had a bad sunburn but, with the use of Vanicream, all was gone in 5 weeks. No other problems. Google will give you a list of all proton radiation centers in US. Of course, I am partial to the MN Mayo Clinic.