I would guess I kept using mine for about 3 or 4 months past finishing rads. Recovery can take a long time to rebuild patients bodies who have been thru so much. Unfortunately none of us are ever able to get well as fast as we think we should.

Its usually 2 - 3 weeks post rads when patients suddenly notice they actually feel almost like their former selves. But, recovery can be full of ups and downs with a few setbacks as well. As long as your father is able to push himself to take in at least 2500 calories and 48-64 oz of water daily he should be ok to slowly start getting back into his regular routine. We all need a reason to get up in the morning! Some patients need routine while others need to see their progress and others cant stand to sit still for more than they absolutely have to., Hopefully the work your father does is not too strenuous and does not involve being around alot of different people. Most patients have their resistance to colds, flu, germs, etc lowered for quite some time after finishing rads/chemo. It can take patients years until their body is fullhy recovered and their bloodwork goes back to their pre-cancer normal levels. Recovery is something nobody likes... especially the setbacks after thinking "hey everything has been pretty good" ! It just take more time than any of us like.

Keep up the higher caloric intake and water for at the very least the first post yr end of rads celebration.