Amber, this is just a guess, but as far as the "single agent" I know I began chemo with just one drug. That I was later switched to a combination involved something unrelated to your dad's treament. With regard to nutrition and his trouble eating, I would strongly suggest he and his doctors take a hard look at a PEG. If he has swallowing difficulty now, I cannot imagine how he will manage to take necessary meds and adequate water and nutrition down the road. I was absolutely unable to swallow the meds I needed at the end of treatment for pain, and without the PEG I would have been up the creek. A number of people have gone through rad/chemo without a feeding tube, but some of us simply would not have been able to do it without. If either of you has questions about a PEG, you may contact me directly and I will be happy to answer them. My experience with it was completely positive.