Gamma Knife is a type of radiosurgery which precisely delivers high doses of radiation to treat brain tumors and other brain abnormalities. Synonyms for Gamma Knife include stereotactic radiosurgery, radiotherapy, brain surgery, and radiation therapy. Stereotactic radiosurgery is a form of radiation therapy and is often used to treat cancer. Brain surgery refers to surgical procedures which are performed on the brain, whereas radiation therapy is the use of high-energy radiation to kill cancer cells. These different terms often refer to the same procedure or treatment but are used interchangeably depending on the context and situation.