Wendy,
Sleeping is very normal at this stage and please be prepared for the fact that he may want to only get out of bed to do his treaments and then get back in bed until the next one. You will need to keep up with the amount of liquids and calories he is consuming daily during this time- [monitor his weight and most importantly his liquids so he doesn't get dehydrated] You might want to get some Pedialyte [found in the baby isle in gro. stores] in the pantry - it is good for replenishing electrolytes
quickly - Gatoraide also helps- you don't want to have to haul him to the ER for an IV if you can help it. If he doesn't want to eat or drink during rad- it's gonna be tough but you need to stay on top of that. Are you charting his liquid and calorie intake daily? Amy