Gamma Knife (Radiosurgery)


What is Gamma Knife®?

Gamma Knife is an advanced form of radiation therapy that treats brain tumors and other complex conditions with surgical precision. It aims hundreds of targeted radiation beams at tumors, delivering high-dose treatment with minimal damage to surrounding tissue.

How Does Gamma Knife Work?

Despite its name, Gamma Knife treatments are non-invasive and require no incision. Instead, highly focused radiation beams are aimed at the treatment area. This tight-to-the-tumor precision minimizes potential damage to surrounding tissue. Gamma Knife treatment is often performed in a single outpatient session.

What Is Gamma Knife Used For?

It can be used to treat several conditions, including:

  • Brain tumor – A tissue mass that can be cancerous or noncancerous
  • Arteriovenous malformation (AVM) – An abnormal blood vessel formation
  • Pituitary adenoma – A noncancerous tumor in the pituitary gland
  • Meningioma – A tumor in the membrane covering the brain or spinal cord
  • Acoustic neuroma – A noncancerous tumor on the nerve connecting the ear to the brain
  • Trigeminal neuralgia – A painful nerve condition

Advantages of Gamma Knife

Gamma Knife offers several advantages, including:

  • Noninvasive and painless
  • Outpatient procedure with no anesthesia
  • Shorter treatment time than traditional radiation therapy
  • Precise radiation delivery with reduced side effects
  • Less damage to surrounding to tissue

Available at Mercy Hospital Oklahoma City, Gamma Knife precisely treats brain tumors and other complex conditions while sparing nearby healthy tissue. 

Gamma Knife Procedure:   What to Expect


A team of experts develops a personalized plan based on your condition and unique needs. Imaging tools like CT and MRI scans are used to precisely target the treatment area.


A head frame helps you remain still during radiation delivery, and the table you’re positioned on adjusts to the treatment area. You’ll be awake and able to talk to your care team, who monitors you continuously. Depending on your condition, treatment can last from a few minutes to several hours.


Gamma Knife often requires only one outpatient treatment session. You’ll likely be released after a few hours and can resume regular activities the same day.

Gamma Knife Side Effects

Temporary side effects may include headache, fatigue, hair loss in the treatment area or skin changes like redness, itching and peeling. Side effects usually go away a few months after treatment, but it’s possible they’ll become severe or won’t improve. Late side effects can appear months or years after treatment and vary by the area treated and radiation dose. Talk with your care team about potential side effects and ways to manage them.

Discussions on Gamma Knife

Patient Story

Mercy cancer patient Karl Jett shares his brain tumor treatment experience with Gamma Knife targeted radiation therapy.

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