Well, it looks like I may be one of the 6% that GK does not work for. Had my gamma knife in March of 2012 on a 1.87 cm an. Everything seemed to go well and the an turned necrotic in the center on the first & second follow up MRI's. Now, however, the "dead space" is filling in and the an is the same size as it was when we started. In other words, it may be growing and filling in the dead space that was created by the GK. I understand that the an was never going to go away but it should have shrunk somewhat as the inside turned necrotic and the an imploded on itself. Now I may have to consider surgery and I am, frankly, scared to death. Has anyone had this experience? What advice can you offer me? I've lost 60% of the hearing in my left ear and I have balance issues and tinnitus. These symptoms seem to be static; they are not getting worse. The hearing loss and the tinnitus were present before the GK.