Hello Terry,
I know you have alot of doubts, concerns and questions. Great! Keep firing them in our direction and you will have no end of personal experiences coming back at you. I understand your reluctance to have a PEG, but unless you can force yourself to drink water even though it may taste like oil, I would have one.
It is encouraging that you have had a PET scan. It tells me you have good insurance and doctors that are leaving nothing to chance. I can't imagine you would have any Rad Treatment other than IMRT, also. I wouldn't waste your mental effort on trying to figure out the why of your recurrance. Concentrate on bulking up (out) and maintaining a positive attitude.
You have support here through the Forum, our thoughts and our prayers.
David