I had Gamma Knife surgery 2 years ago and am grateful for it. The only pain was from lidocaine shots to put on the pins for the mask. That lasted only for seconds. The scabs from the pin locations lasted several weeks but never hurt. I didn’t lose any hair even at the pin locations. I’m happy with the results because I had a large meningioma near my optic nerve that could have caused problems with vision later. I was fine after the procedure, just worn out from the stress so I probably napped for a while after. Best of luck.