About the Gamma Knife

The Gamma Knife Procedure

Preoperative Evaluation

Not all patients are good candidates for Gamma Knife surgery. Gamma Knife patients are chosen after thorough evaluation of patient history, medical records, X-rays and other diagnostic tests. The Gamma Knife team includes neurosurgeons, radiation oncologists, radiation physicists and nurses. Team members design and coordinate the treatment plan and confer with the referring physicians to discuss recommendations and patient progress.

Once the Gamma Knife team has decided that the procedure is right for the patient, the Gamma Knife neurosurgeon, radiation oncologist and nurse discuss the procedure with the patient and answer any questions. Blood tests are performed, and the patient is asked not to eat or drink anything after midnight the night before treatment, as before any operation. This decreases the chance of stomach upset during the procedure.
 

The Day of Gamma Knife Surgery

On the morning of treatment a nurse starts an intravenous (IV) line to administer a mild sedative. The patient's scalp is cleansed with alcohol. No hair is shaved. After a local anesthetic is administered, a guiding device (stereotactic frame) is attached to the patient's head with four pins. Any mild discomfort experienced at the time of frame application is transient. Head measurements are recorded to help plan the treatment.
 

Dose Planning

After these measurements are made, an MRI, CT, and/or angiogram are performed and the appropriate images are selected and transferred to the Gamma planning computer. Dose planning generally takes about one hour, depending on the lesion size and location. During the planning process the patient can rest, read a book, visit with family, listen to music or take a nap. After final plans for administering the radiation dose have been made and reviewed by the Gamma Knife team, the patient is moved to the Gamma Knife unit.
 

Treatment

The treatment session usually lasts between 30 minutes and three hours, depending on the amount of radiation necessary. A number of "trips" in and out of the machine is necessary to accurately deliver radiation to the tumor or AVM. During treatment the patient does not feel or hear anything unpleasant. Throughout treatment, the patient is observed by closed circuit television, and is able to communicate with doctors and nurses via two-way intercom. After treatment, the guiding device is removed and the patient can return home after a brief observation period of several hours. The patient can return to work or school, without restrictions the day after treatment.

Who Can Benefit from Gamma Knife Radiosurgery 
Risks of Gamma Knife Surgery