As I stated in my post, I am not a doctor and would never put myself forth as an expert. I repeated what the Doctor at House, where people come from all over the world to have their ANs treated, and where they do hundreds of surgeries a year, told me, namely that "they"(doctors at House) are seeing people who had gamma knife many years ago who now have either cancerous tumors or irradiated tumors that have grown in such a way that they are extremely difficult to remove. No, I did not check out his statement, though I can't imagine why he would have made it up. I would also assume that anyone contemplating treatment would read each comment posted and evaluate it with his medical team.
Although they specialize in microsurgery at House, they also do radiation. In fact, when I first called and told them my age (middle 70's) I was advised that most patients my age choose radio surgery because of the risks involved with surgery. However, since radiation often causes a swelling of the tumor before it shrinks, that would have been impossible for me as a growth of just 2 mm had caused pressure on my trigeminal nerve.