I think it might be prudent to have an ultrasound of your carotid arteries in your neck. A simple non invasive test that will evaluate if they are occluded and if so to what degree. It is really common in people that have been radiated to have scar tissue develop in them. This stems blood flow and definitely causes lightheadedness. This gets worse as time progresses if that is the case.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.