When I had the Gamma Knife back in March, I was fitted with a halo. I was under anesthesia for them to attach it, and when everything was over, I was awake when they u did it. No discomfort. It looks scarier than it is. I had my 6 month check up and the tumor has stopped growing. The Dr. told me it could take months/years for it to shrink or go away. Good luck.