Gamma Knife surgery is a painless computer-guided treatment that delivers highly focused radiation to tumors and lesions in the brain. Gamma Knife surgery is used to treat brain tumors, arteriovenous malformations, trigeminal neuralgia, acoustic neuroma and tremors.
Gamma Knife® surgery is a treatment method that uses radiation and computer-guided planning to treat brain tumors, vascular malformations and other abnormalities in the brain. Despite its name, this procedure does not involve any incisions, not even a skin incision. The Gamma knife is actually a treatment that delivers beams of highly focused radiation. Some 192 "beamlets" of radiation converge and are precisely focused on the targeted area of brain, specifically in the shape of the tumor or lesion, while sparing the surrounding normal tissue.
Gamma Knife surgery is a type of stereotactic radiosurgery. It's also known as Gamma Knife radiosurgery and Gamma Knife radiation.
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Gamma Knife surgery can treat several brain disorders, including:
The Gamma Knife may be helpful if you have a brain lesion or tumor that can’t be reached by traditional surgery techniques or if you’re unable to undergo surgery due to your condition or age. It can also be combined with traditional surgery to prevent tumor regrowth. The Gamma Knife is also used for some conditions that require urgent treatment.
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Gamma Knife treatment involves several steps.
The initial steps are different if the Gamma Knife system uses an external rigid head frame or uses a frameless mask. If using a head frame:
Frameless Gamma Knife systems use a thermoplastic mask that is placed over your face. The mask is then secured to an existing frame on the Gamma Knife table. Your head is held completely still.
These remaining steps are the same for both the frame-based and frameless systems.
Depending on the type and size of the tumor or lesion, more than one treatment session may be needed. Your neurosurgeon and/or radiation oncologist will review your treatment plan with you.
The actual Gamma Knife treatment is painless. There is no heat or noise nor will you feel any discomfort during the treatment. You may listen to music or nap during the procedure.
While risks related to the procedure are typically low, risks and/or side effects of Gamma Knife surgery may include:
There are many benefits of Gamma Knife surgery over traditional surgery. Gamma Knife surgery:
It’s covered by most insurance and Medicare (but always check with your insurance provider).
The success of the Gamma Knife procedure depends on the size, location, type of lesion, your personal medical history, and other factors. Discuss your expectations and outlook with your neurosurgeon and your radiation oncologist before treatment.
The goal of Gamma Knife surgery is for the radiation to stabilize, shrink or destroy the tumor or lesion. Depending on your condition, you may or may not need additional Gamma Knife treatment or traditional now-more-manageable surgery. You will have follow-up CT and/or MRI scans to check on treatment progress.
It may take weeks, months, a year (or sometimes longer) to see the full effects of treatment. For example, pain relief if you have trigeminal neuralgia can occur anytime between one day and six months, with most people improving within one month. Cancerous tumors typically become stable or get smaller over a period of weeks to months. Many noncancerous tumors stop growing immediately (the main goal), but may not get smaller in size. Arteriovenous malformations may take two to three years to resolve after treatment.
Call if you feel or notice any of the following symptoms:
If you experience nausea, vomiting, severe headache, visual changes, difficulty speaking, a seizure, or any other symptom unusual for you, contact your physician immediately or go to the nearest emergency room.
A note from Cleveland Clinic
Gamma knife is a highly effective treatment with minimal or no associated adverse effects. Because of its ability to stabilize or reduce the size of a tumor or lesion, often only one treatment is required; however, occasionally gamma knife can be repeated safely and successfully.
For more information download our Gamma Knife Treatment Guide.
Last reviewed by a Cleveland Clinic medical professional on 04/16/2021.
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