Books on Lumbar Sacral Radiation Plexopathy

Can anyone recommend any books about radiation plexopathy? I was diagnosed this year with it as a result of radiation treatment for colorectal cancer I had 23 years ago. I've had many of the symptoms for years, but this last year had gotten much worse, went to the Neurologist, tested and diagnosed. Also, has anyone out there had any results from any drugs and/or alternative treatments? I have tried gabapentin (which I'm still on but a very low dose - not doing much and everytime I try to increase I get bad side effects..I'm ready to give up on that) and I've tried acupuncture - works a little bit for a couple days and that's it. My symptoms are twitching, terrible aching, buzzing and tightening from my buttocks down to my feet. I also have some weakness in my legs. It's constant and never goes away. Any help/advice is appreciated. Thanks!