I am almost 10 years out and am losing my voice. It is a combination of neuromuscular issues from radiation. I am also losing my swallowing and breathing muscles. It started about 5 years out but I do think it is more the exception. They statistic I was told was .5% but also includes any cancers with radiation to the upper chest.
I say this with hesitation because I do not want everyone to rush to the doctor with similar problems. Statistically, if correct as I have not verified other than one study, that could mean 50-100 people a year with similar issues. With the amount of muscle loss I have experienced I wonder which atrophy is next and will it bring the whole house of cards down. I am amazed at what I can still do and have worked up to doing after nothing left but a bucket of bones and tendons at one point.
My swallowing problems started with atrophy of the constrictors and just keeps moving down the throat which causes aspiration. Also, the right side of my epiglottis no longer lifts so I choke on liquids. I have been told it is progressive, untreatable and not curable. I just haven't found what works yet. I still eat regular foods but try to drink mostly water. Protein shakes and smoothies throughout the day. I have had 6 barium swallow tests and motility studies and other swallowing tests and it has always been about the same as a few weeks after treatment with sporadic muscle spasms from the mouth to the stomach and through the intestines that seem to be the culprit with a variety of suggested possibilities from brain stem damage from radiation to nerve damage from scar tissue in the myelin from radiation damage to autonomic nervous system/medulla oblongata damage from radiation to spinal cord damage from radiation, etc., etc., etc.
The only agreement is all the doctors I have seen for almost 10 years all blame it on radiation except the Radiation Oncologist, of course.

I did get to see how bad my signature was during treatment when they flashed out all the treatment consents I signed fully knowing long term damage could result. I would probably do it over if I had to. I know I couldn't of crammed much more living in than what I did experience while the medical community scratched their head for years.