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Gamma Knife

Gamma knife treatment

​Gamma Knife is a type of radiosurgery that sends focused beams of high-energy ​radiation to a specific target within the brain. It delivers radiation in a more accurate way than other forms of radiation therapy, which protects normal brain tissue. This provides advanced options for your healthcare provider to treat brain tumours and other conditions.

Gamma Knife doesn’t use a knife and isn’t a type of surgery. You won’t need to be put to sleep (have anesthesia) during this procedure. Imaging, such as magnetic resonance imaging (MRI), done before or on the day of your treatment, gets 3-dimensional pictures of your brain to help plan treatment. 

Gamma Knife treatment in Alberta is only available at the University of Alberta Hospital in Edmonton. The Gamma Knife team includes neurosurgeons, radiation oncologists, medical physicists, neuroradiologists, nurses, and radiation therapists.

Types of Gamma Knife treatment​​​

It's necessary to hold your head still during a Gamma Knife procedure to allow the highest degree of accuracy. This can be done in 2 ways:

Mask-based treatment uses a mask to hold your head in place during treatment. The mask will be fitted to the shape of your face.

Frame-based treatment uses a frame held tightly to your head with 4 metal pins during treatment.

The type of treatment will be decided by the Gamma Knife treatment team, depending on what is best for your condition.

​​​What you need to know

If you're having Gamma Knife treatment, your healthcare provider will explain the risks and benefits during your  consultation. Additional information will be shared electronically or on paper. The following information will answer many of your questions. You can also watch a video that shows you what to expect.

Conditions treated by Gamma Knife
The Gamma Knife treats brain conditions such as tumours,  abnormal blood vessels, facial pain, and other neurological disorders.

Pain and comfort
The treatment itself isn’t painful. If you’re having frame-based treatment, the frame and pins that hold the head frame in place may be uncomfortable. You'll be awake during the treatment, so your doctor may offer you medicine to help you relax. This may make you a bit sleepy.

After treatment
Most people can go home the same day as treatment. If you live out of town and need to have an angiogram (an x-ray of the blood vessels), you'll need to stay overnight in Edmonton (but not in the hospital).

Preparing for Treatment

Follow all the instructions that your healthcare provider gave you at your consultation. Let the healthcare team know if you have diabetes. You will get special instructions about using your medicines on the day of treatment.

Make sure you have a ride home. You won’t be able to drive after your treatment because you may be given medicines that make you sleepy.

The day before treatment
On the day before treatment, wash your hair. Don't use any hair products like gel, mousse, or hairspray. Don't use any scented perfumes, lotions, or after shave.

Special instructions​:

​​​​​Mask-based treatment 
​Frame-based treatment
​Trim any hair from the face so the mask will fit closely to the face.
​Don't eat or drink anything after midnight.

What to bring to your treatment
​Bring the following items to your treatment:

  • photo identification (ID)
  • your Alberta Personal Health Card and your insurance card (if you have one)
  • a light snack for after your treatment
  • medicines you need to take during the day
  • an updated list of your medicines, including vitamins and herbal products
  • a magazine or book
  • your phone (if you want to listen to music during your treatment)
  • indoor shoes or slippers

Don’t bring your valuable items to the hospital. The hospital is not responsible for lost or missing items.

​​​Day of treatment

On the morning of the treatment take your medicines with a few sips of water. You can bring a friend or family member with you to the hospital.

Check-in at the hospital​​​

Check-in at the University of Alberta Hospital. You’ll then be sent to the Gamma Knife waiting area.

​​​Before your treatment

The Gamma Knife staff will ask you to change into a hospital gown and put your belongings in a locker. They will also:

  • explain what will happen during the treatment and answer your questions
  • you may be given​ an intravenous (I.V.​) in your hand or arm if the healthcare team needs to give you fluids, medicine and contrast dye (if you are having an MRI)​
  • check your heart rate, blood pressure, and temperature (called your vital signs)

You may need imaging tests, such as MRI, and other tests depending on your care needs. These tests may be done the day of your treatment, or they may have already been done in the days before.

​​Mask-based treatment
​Frame-based treatment
​You'll be fitted with a mask.
  • ​The fitting is done by putting a warm mask on your face and fitting it to the shape of your face.
  • The mask is attached to a support cushion for your head that you will lie on during the treatment.
  • The mask-fitting will take about 20 minutes.
​A head frame will be put on your head.
  • ​It will be held closely to your head with pins.
  • You'll be provided with mild sedation and medicine to numb where the pins are placed into the skin.

Treatment planning​​​

The Gamma Knife team will use the pictures from your imaging tests to decide:

  • the exact location of the treatment area
  • the dose of radiation
  • the length and number of treatments

You'll be able to rest in a patient room while the team is planning your treatment.

Gamma Knife treatment​​​

You'll lie down on the Gamma Knife treatment table. The healthcare team will attach some medical equipment to your body to check your vital signs during the treatment.

A radiation therapist will watch you on camera during your treatment. They'll be able to talk to you during the treatment using a microphone system. You'll be holding a call bell that you can ring if you need to get their attention.

During the treatment you'll be able to listen to music to help you relax.

​​​After the treatment

You will go to a patient room for 30 to 60 minutes. The healthcare team will check to see how you’re doing and you can have something to eat and drink.

Specific information for mask-based and frame-based treatment:

Mask-based treatment

  • The mask will be removed right after your treatment.

Frame-based treatment

  • The frame will be removed in the patient room. You'll get a small dressing to put on the skin where the pins were.
  • Don’t wash your hair for at least 48 hours after the treatment. You may notice a bit of blood stuck to your hair from the head frame.
  • You may have swelling, bruising, or pain in the area where the pins were. Put a cold cloth or icepack on the skin for 10 minutes. Repeat as needed.
  • Take off the dressing the day after treatment. Keep bandages on your forehead for 48 hours. You shouldn't have any bleeding after the treatment. If you do, put pressure on the area with a clean bandage or cloth for about 5 minutes until the bleeding stops.
Before you go home, the Gamma Knife staff will give you discharge instructions and let you know the date and time of any follow-up appointments. You may be at the hospital until 4:30 p.m. or later. 

It’s important to do the following:
  • Drink plenty of fluids. This helps flush out any contrast dye if you had an MRI.
  • Wait until the next morning before you drive. Some medicines may affect your ability to drive. Make sure you have someone to drive you home and stay with you the first night after treatment.
  • You can return to your regular activities the day after the procedure unless your healthcare provider gives you different instructions.
  • If you have headaches, take acetaminophen (Tylenol) or ibuprofen (Advil), as directed on the bottle. To help avoid headaches, sleep with your head slightly raised for a few nights.
  • If you have diabetes, check your blood sugar level and take your medicines as prescribed.

Current as of: October 3, 2023

Author: Neurosciences, University of Alberta, Alberta Health Services