Mike,
Sorry for the delay in answering your question, but this is the first time I ventured into this part of the Head and Neck section.
To try and answer your question. During and after our radiation treatments. Our neck and throat swell, this causes the passageway to narrow. I was unaware of this at first and in the first year choked on my food 4 times. Luckily, my son was either next to me or in the other room and helped me clear the stuck food. I'm more careful now and take smaller bites.
Also, a dry mouth plays a big part in the eating process.( A side effect of radiation ) I always have at least 2 types of fluid near by. A cup of coffee and a glass of water. Our necks and throat may never return to what they once were, so we have a new normal.
Has he gone for any physical therapy to stretch his neck muscles ? There is a gentle massage he can learn to stimulate the lymphnode system also that is helpful. It will relieve some tightness in the face and neck if that is an issue of his ?
My Best to Everyone Here