Have they considered stereotactic radiation, tomotherapy? This is radiation but it is beamed to the specific tumor and is less destructive on the parts of the body surrounding the tumor. And it does not destroy all the other cells in your body. It also takes less treatments.
I underwent it 5 treatments, 1 every other day for a week and a half (no weekends) and it reduced my tumor to next to nothing and dropped the SUV to a level 2. I couldn't believe it. Might be worth looking into.
Good luck and God Bless