Caco, I realize you were addressing the other David but I'll weigh in if you don't mind. I also went through RT without a PEG, although I didn't have chemo as well.

I found the mouth and throat sores so painful and debilitating that, by about week 3 or so, I was wishing I'd gotten the PEG. We're of course all different. I've been a lifelong canker sore sufferer so maybe that made my mouth more vulnerable, dunno. But I found it nearly impossible to drink even liquid nutrition and water so didn't get nearly enough. Lost 30 pounds, which of course isn't uncommon.

It took me a good 6 months after the end of RT before I could even tolerate solid food.

Perhaps others will add their comments. Best of luck to you and your dad. All your choices have been good ones so far and I have no doubt you'll do the same with the PEG issue!