Hey Tedebear,
Sorry to hear what your wife and you are going through. My husband started chemo/rad Jan. 12 and he has three more rads to go. It has been a tough road, but he has made it. Starting feeding thru the PEG tube about 3 weeks into it. Sores and blisters in mouth and throat and neck outside cracked and bleeding. What has helped get through it the most is taking the meds right on time and a great support system through God and our church. I have such a hard time watching him suffer. It seems like we have been in a bubble and life has just stopped except for cancer treatments and making it through each day. But almost done and he has had 40 rad treatments at the max.
I will keep you in my prayers...everyone is different. Some here I have read have had very little effects during treatments, others like Dan have had more. Try and keep her eating good. Dan started taking in little food thru the PEG and they almost had to stop treatment, get him healed more, and then start again. It does happen, but not the best way to go.

Take care,
Debbie