What is a Gamma Knife surgery?

Gamma Knife surgery, also known as Gamma Knife radiosurgery or Gamma Knife radiation, is a brain cancer treatment option using advanced radiation therapy. During Gamma Knife treatment, a machine will deliver a single, highly focused, high dosage of radiation directly to the targeted area. Due to the ability to hyper-target, the radiation causes minimal if any damage to the surrounding tissue. Gamma Knife is most effective on brain tumors or other abnormalities that are less than one inch in diameter.

Although the name Gamma Knife implies this is a surgical procedure, it is not.

Who should have Gamma Knife surgery?

Your Mercy Health doctor and cancer care team will evaluate your case to determine if you are a candidate for Gamma Knife. The team will consider your age, your overall health, location and size of the tumor as well as any other treatments you have had for this condition.

When appropriate, Gamma Knife is a treatment option for patients who have the following conditions:

  • Brain tumors
  • Abnormal blood vessel formations (arteriovenous malformations or AVM)
  • Epilepsy
  • Trigeminal neuralgia

The Mercy Health team often recommends Gamma Knife for patients who:

  • Have difficult to reach brain tumors
  • Have brain tumors very close to the brain stem or optic nerve
  • Aren’t healthy enough to withstand traditional brain surgery
  • Failed traditional brain surgery
  • Are having chemotherapy and radiation therapy for other cancers and have metastatic brain tumors as well

Risks of a Gamma Knife radiation

Risks associated with Gamma Knife include: 

  • Nausea 
  • Vomiting
  • Dizziness
  • Headaches
  • Tenderness where screws are placed in the head
  • Hair loss at the affected area
  • Damage to areas in the brain around the affected area

Advantages of Gamma Knife radiation

Advantages of Gamma Knife surgery over traditional brain surgery include:

  • Precisely targeted - Gamma Knife surgery is very accurate. The technology can precisely target the brain tumor so that the radiation does not damage tissue and nerves around the tumor.
  • No incisions needed - Gamma Knife surgery is a form of radiation therapy, so no incision is required. Therefore, any complications typically associated with an incision in the skull as well as general anesthesia can be avoided.
  • One treatment period - Most patients can be treated with one treatment. The treatment will take anywhere from 10 minutes to a few hours.
  • High success rate - There is a high success rate for patients who are carefully selected for this treatment.

What to expect during a Gamma Knife radiation?

Gamma Knife surgery aims low dose radiation beams from various angles around the head targeted directly at your brain tumor. The beams meet at the center of the tumor to form a high dose radiation treatment. 

Prior to the procedure, Gamma Knife surgery uses 3-D imaging (MRI and CT scan) to precisely target the tumor.

When ready for the procedure, your doctor will place a frame around your head to keep it still during the procedure. Your scalp will be numbed with a local anesthesia before your care team uses tiny screws or pins to position the frame in place. A clear helmet with small holes will be placed on your head. The holes are where the radiation beams will be aimed at your head.

The entire procedure will take from 10 minutes to a couple of hours, depending on the complexity of your case. When completed, you will be monitored closely by your care team before being discharged to go home.

Recovery from a Gamma Knife surgery

Most patients who have Gamma Knife radiation can go home from the hospital the day of the procedure. Your doctor will instruct you to take it easy for 12 to 24 hours and gradually resume your normal routine over a few days. 

Follow your doctor’s discharge instructions including:

  • Pain management options
  • Caring for your incisions
  • Activity level 
  • Follow-up visit schedule

The effects associated with Gamma Knife surgery can develop a year or more after the treatment has concluded. You will need regular follow-up visits and MRIs to monitor the progress.

Call your doctor if you experience any of the following symptoms:

  • Swelling, pain or redness 
  • Sites where the pins in the skull were located start feeling hot
  • Drainage from incision sites that smells foul
  • Develop a fever of over 101 degrees F

If you start vomiting, develop a severe headache, have difficulty speaking or start having seizures, call 911 immediately.

Results from Gamma Knife

The goal of radiation therapy with Gamma Knife is to slowly shrink and dissolve the brain tumor lesion. When successful, cancerous brain tumors shrink within a few months. The success rate after the procedure depends on a variety of factors including:

  • Size of tumor
  • Where the tumor is located
  • Type of lesion
  • Overall health before the procedure

Find a brain cancer specialist nearby

Mercy Health locations that can treat you