Hi, Tony, I think I get what you mean and I agree....The Gamma Knife isn't precise enough for the problems that require absolute accuracy in a Pallidotomy (so close to the optic nerve). The Gamma Knife is safer for a Thallidotomy which is performed in a different area and usually is used primarily for reducing tremor. Pallidotomy is used to relieve rigidity and dyskinesia. Bev