What is Gamma Knife?

Gamma Knife® radiosurgery is a precise and powerful treatment for brain disorders. It is noninvasive, effective and safe. This makes it the optimal choice for treating a wide variety of conditions including benign or malignant brain tumors, blood vessel malformations, trigeminal neuralgia (also called tic douloureux) and tremor.

Gamma Knife is not an actual knife. It is a method of radiosurgery that delivers extremely focused beams of cobalt radiation to precise targets in the brain – as many as 201 individual beams. Individually, the beams are too weak to damage healthy tissue. Together, they converge to deliver powerful treatment to a single point.

Another term for this type of noninvasive neurosurgery is "stereotactic" radiosurgery. This refers to directing radiation to a specific focal point using an external, three-dimensional frame of reference -- such as the head frame used in Gamma Knife radiosurgery.

There are many benefits to Gamma Knife radiosurgery. More than 30,000 patients safely undergo Gamma Knife radiosurgery each year. The method has been used worldwide since 1968. Gamma Knife radiosurgery allows patients to quickly return to their normal routines. In most cases, only a single procedure is necessary. In addition, radiosurgery is less expensive than conventional neurosurgery. It eliminates the need for lengthy hospitalization, medications and rehabilitation.

What To Expect During Gamma Knife Surgery

Our experienced Gamma Knife team provides patients with maximum safety and efficacy. Skilled pre-treatment planning and the radiation's focused delivery method lead to improved patient outcomes, enhanced quality of life and virtually nonexistent damage to healthy brain tissue.

Your physician and our Gamma Knife team members will discuss the radiosurgery with you before the procedure takes place. Since Gamma Knife radiosurgery is noninvasive, it is not necessary to shave or cut your hair.


During Surgery

Gamma Knife radiosurgery planning and treatment are performed on the same day. Treatment includes three phases: fitting the head frame, procedure planning and actual procedure.

Fitting the Head Frame

One of the key components in Gamma Knife radiosurgery is what is called the stereotactic head frame. The frame allows the physician to accurately pinpoint the area within your brain that will be treated. The frame is lightweight and attaches to the head with four screws, which ensures that the radiation beams are precisely directed to the target. In addition, the frame prevents the head from moving during imaging and treatment. A local anesthetic will be applied where the screws are to be attached.

Once the head frame is in place, images will be taken of your brain. This imaging may include magnetic resonance imaging (MRI), computed tomography (CT) or angiography. Imaging will determine the exact size, shape and position of the target within your brain.

Radiosurgical Planning

The next stage is radiosurgical planning. Once the images have been taken, you are allowed to rest while the Gamma Knife physicians develop a precise radiosurgical plan. The plan is made using a specially designed computer that helps calculate how the radiosurgical procedure should be performed. This generally takes one to two hours. During this time you can rest, watch television, read and use the restroom. The stereotactic head frame will remain attached.

The Radiosurgical Procedure

Once the radiosurgical plan is completed, the actual radiosurgical procedure can begin. You will lie down on the procedure couch and the head frame will be attached to a helmet. You will be awake throughout and will be able to communicate with the Gamma Knife team through an audio and video connection. We will be monitoring you at all times. The procedure is silent and painless.

The procedure time will last a few minutes to more than an hour, depending on the size and shape of the targeted area.

After Surgery

Most patients should be able to return to their normal routines within a day or so. Some patients may be required to lie quietly for several hours after treatment or stay overnight for observation.

Risks and Outcomes of Gamma Knife Surgery

Follow-up is key when you've had Gamma Knife radiosurgery. That is because the effects of the radiosurgery occur over a period of weeks or months. Treatment is designed to stop the growth of tumors or lesions over a period of time. It is important that you stay in contact with your physician to determine progress of your treatment. This may involve follow-up imaging such as MRI, CT or angiography.

Some patients may experience a mild headache or minor swelling where the head frame was attached. Your doctor will discuss any potential side effects.