Gamma Knife (Neurosurgery)
		Body Area: Head / Neck
		Body Parts: Eyes
		Symptoms: Change in Vision
		Description:
A gamma knife is used in a procedure, to shrink brain tumors in a single dose of radiation.  In the procedure, the patient wears a specialized helmet that negates the gamma rays from killing healthy brain tissue, and keeps the tumor stationary.  Next, a dose of gamma radiation is administered to the tumor to shrink it.