In 1989, Mayo Clinic became the world’s sixth medical center and the third in the United States to use the gamma knife procedure. The powerful, 17-ton piece of neurosurgical equipment destroys deep-seated brain lesions without surgery, using precisely focused beams of radiation to destroy inoperable brain masses.
The gamma knife uses stereotactic radiosurgery, which combines stereotactic neurosurgery with radiation treatment. Beams of radiation destroy a targeted area within the brain while sparing the surrounding brain tissue and other vital structures. With the gamma knife, the patient has none of the risks of traditional surgery such as post-operative bleeding and infection. The procedure itself is painless.
According to Dr. Patrick Kelly of the Department of Neurologic Surgery, "The gamma knife works most effectively on small masses of blood vessels within the brain called arteriovenous malformations (AVM). It also works well for various benign tumors at the base of the skull and any small, well-defined mass.”
The gamma knife is deceptive, said Dr. Kelly, because the unit cannot be held in the hand and does not look like a knife—if simply performs like a surgical knife. The equipment looks like a surgical table with a huge hair dryer or helmet at once end of it. The radiation comes through small tubes in the helmet, which is remote-controlled by the neurosurgeon in a nearby room. The patient can see the neurosurgeon on a TV screen within the treatment room.
“Mayo can make these high technology procedures cost-effective because we have the patient volume to keep the equipment in use doing the types of procedure it was meant to do,” Dr. Kelly said. “Its presence here will increase the number of patients coming to Mayo and make us a tertiary care center that is better able to help these patients.”