As long as he is getting enough nutrition and fluid things should be okay. People tend to fall apart if they become dehydrated and/or malnourished. It's not easy in fact it's brutal but knowing what you are facing before hand helps in that you are prepared and have something on hand to deal with it. The first few weeks are okay. The last 4-5 (including the two following treatment) are the worst as radiation is cumulative people think rads has stopped the pain will stop but NO. There's also thrush to look out for. Have magic mouthwash and adequate pain meds on hand if you can. Make sure he does his rinses and continues to swallow if he's on a peg. take care.