Larrysdaughter,
My understanding is that radiation actually continues to build/burn/fight for the month after treatment. My dad finished his treatment November 18th and just started to swallow last Saturday, still occasionally uses suction, and has gone from very tired to tired. His voice is croakey etc.
But there are little improvements all the time and a great relief to be finished with treatment. Also look for depression and general anxiety for yourself, mother and father during the time you wait for results.