Ed,
It's strange that you should mention this. I had a similar experience a couple of weeks ago that has had me rattled ever since.
I've had some ongoing back-of-the-neck pain that my oncologist (my primary care doctor) wanted to check out, so he ordered cervical spine x-rays. The machine was obviously zeroed in on basically the same area where I had radiation 15 years ago. The technician seemed to be having problems with the machine and after a couple of shots she moved me to a different one to complete the process. Within a few hours, the lining of my mouth (tongue, gums, back of the throat) was in pain, similar to what I had felt a couple of weeks into radiation. I called my doctor in a panic, and he assured me that the conventional x-ray machines would not generate enough radiation to cause any damage, but frankly I'm at a loss to understand why I had that kind of sudden reaction.
The pain has been subsiding gradually each day, but you can be sure I'm watching that area very closely again.
Cathy