Has anyone experienced brachial plexopathy?

I have been diagnosed with brachial plexopathy caused by radiation for breast cancer 27 years ago. I've had several surgeries in the past on my arm including a tendon transfer that did not work. These were an attempt to give me better functioning in my hand because the nerves were not working and the doctors apparently didn't know about the severe damage to my brachial plexus. I am right- handed and my hand is very dysfunctional. I cannot raise my shoulder and the muscles in my arm are atrophying. Has anyone had this experience?