What Is the Gamma Knife Procedure?

According to the Mayo Clinic, Gamma Knife radiosurgery is an alternative treatment for traditional brain surgery. Gamma Knife therapy provides radiation directly to the tumor without a physical incision to the skull.

In this kind of radiosurgery, nearly 200 beams of radiation are targeted on the problem area in the brain, explains the Mayo Clinic. While each beam causes only a minimal effect on brain tissue it passes through, the point at which the beams meet delivers a strong dose of radiation on the tumor. Gamma Knife radiosurgery can be completed in one day and is the preferred method when a tumor is in a particularly difficult-to-reach place or the patient is not in good enough health to undergo traditional brain surgery.

Children usually receive anesthesia during the imaging and the surgery; adults are typically awake but may receive a mild sedative. Once imaging is done the results of the scans are relayed into a computer and the radiosurgery team analyzes the information and prepares for the procedure. This process takes about one to two hours, states Mayo Clinic.

When planning is complete, the patient lies down on a bed which slides into the Gamma Knife machine, and the frame on the patient’s head is secured to a helmet inside of the machine, according to Mayo Clinic. During the procedure the machine sends about 200 tiny beams of radiation to the precise location of the brain abnormality. Each individual beam has little effect on the tissue, but the focus of 200 beams delivers a strong dose of radiation to the area where the beams meet.

The actual surgery lasts anywhere between one to four hours depending on the size of the area treated, explains Mayo Clinic. The precision of Gamma Knife radiosurgery minimizes damage to healthy tissue around the target and often causes fewer side effects than traditional surgery.