Hi Chuck, I had to have radiation to my neck and throat area and had/have the same problem as you. I found that it happened all throughout the day but for me it was worse at night when I was trying to sleep. So I drank hot herbal tea with lots of lemon before I went to bed. I also gargled with a mixture of warm water, salt, and baking soda. That seemed to help me during the day.
Hope that helps you out a bit!