My case is far simpler but I do have tightness and occasional cramping along the side of my neck and under my chin, places where the BOT primary and node cancers were hit the most by radiation. I also get a tightness running along the backside of my neck up behind my ear.

I just do a lot of neck and head turning and twisting and bending during the day. Whenever I feel any tightness I just start a short routine to relieve the tightness. So far this working for me.