What is a stereotactic radiosurgery?
Stereotactic radiosurgery (also called Gamma Knife) is a treatment for certain diseases in the brain. It uses very precise beams of radiation to treat the affected area of the brain. Because the beams only focus on the area that requires treatment, the chances of nearby brain tissue being affected are low.
Reasons for stereotactic radiosurgery
Stereotactic radiosurgery is used for treatment for certain diseases of the brain, including:
Risks of stereotactic radiosurgery
The risks of stereotactic radiosurgery may vary depending on your child’s condition, age and health. These risks may include injury to some of the surrounding brain tissue and the possibility of needing additional treatment if the radiosurgery does not work the first time.
Preparing for stereotactic radiosurgery
If your child is having stereotactic radiosurgery, they will have a clinic visit and you will have an opportunity to meet with the neurosurgeon before the procedure. During the visit, you should expect the following:
- A health assessment to make sure your child is healthy and that it is safe to have general anesthesia and to go ahead with the procedure. This will also include a discussion about allergies, specifically, if your child is allergic to contrast dye.
- Pre-surgical bloodwork.
- A referral to a hospital that has specialized equipment to perform the procedure. If your child is a patient at SickKids, they will be referred to a team at the University Health Network (UHN).
- An overview of the procedure, discussion of the risks and benefits, and a review of the consent form with both your child’s neurosurgeon and the team at the hospital where the stereotactic radiosurgery will be taking place.
- A referral to the anesthesia clinic for further assessment and discussion.
If your child’s hospital does not have stereotactic radiation equipment, and they need to be referred to another hospital to have the procedure done, they will also have a clinic visit at that hospital’s stereotactic radiation clinic.
Giving consent before the procedure
Before the procedure, the neurosurgeon and stereotactic radiosurgery team will go over how and why the procedure is done, as well as the potential benefits and risks. They will also discuss what will be done to reduce these risks and will help you weigh the benefits against the risks. It is important that you understand all potential risks and benefits of the procedure and that all your questions are answered. If you agree to the procedure, you can give consent for the stereotactic radiosurgery by signing the consent form.
How to prepare your child for the procedure
Before any treatment, it is important to talk to your child about what will happen. When talking to your child, use words they can understand. Let your child know that medicines will be given to make them sleep during the procedure.
Children feel less anxious and scared when they know what to expect. Children also feel less worried when their parents are calm and supportive.
Pre-procedure MRI
If your child is able to be awake during the MRI, this will be scheduled at the hospital where the stereotactic radiosurgery will be taking place for the week before the procedure date. This is also when pre-procedure bloodwork will be done. It is ideal if your child is awake during the MRI, as this reduces the time your child will need to spend under anesthesia on the day of the procedure. If your child is unable to be awake during the MRI, they will need to do the MRI under general anesthesia on the day of the procedure prior to stereotactic radiosurgery.
If your child becomes ill within two days before the procedure
It is important that your child is healthy on the day of their procedure. If your child starts to feel unwell or has a fever within two days before the surgery, let their health-care provider know. Your child’s procedure may need to be rescheduled.
Food, drink and medicines before the procedure
- Your child’s stomach must be empty before general anesthetic.
- If your child has special needs during fasting, talk to their health-care provider to make a plan.
- Discuss with your child’s health-care provider about taking their regular morning medicines with a sip of water up to two hours before the procedure.
- Medicines such as acetylsalicylic acid (ASA), naproxen or ibuprofen, warfarin, or enoxaparin may increase the risk of bleeding. If your child is on any of these medications, consult with your child’s neurosurgeon before the procedure to create a plan of care.
For more information on preparing your child for their procedure see Coming for surgery.
On the day of the procedure
Arrive at the stereotactic radiosurgery clinic two hours before the planned time of your child’s procedure. Be sure to bring your child’s health card and any medicines your child is taking in their original containers.
Your child will have medicine for pain
Children are given medicine for treatments that may be frightening, uncomfortable or painful. For stereotactic radiosurgery, all children will be given general anesthesia. This will be done by the pediatric anesthesia team in an area near the treatment unit. Your child will remain asleep under general anesthesia for the entire procedure. Post surgery, they may also be given medications to help manage their pain.
Attaching the head frame
Once under general anesthesia, your child will have the stereotactic head frame put on their head. The neurosurgeon will attach the lightweight titanium frame to your child’s head using adjustable posts and pins.
The head frame is an important part of your child’s treatment, as it will keep their head very still during imaging and the procedure. The head frame will also ensure that the treatment only affects the area of the brain that is being targeted. The frame will stay on for the entire procedure.
Imaging and treatment planning
Before the procedure—either the week prior or on the day of—images of your child’s head and brain will be taken via computed tomography (CT) scan, magnetic resonance imaging (MRI) and cerebral angiogram. These images will confirm the exact size, shape and position of the target in the brain. It is important to discuss whether your child has any allergies to contrast dye so that a plan can be made before they are given medication for the procedure.
Using the results from imaging, a treatment plan will be developed by your child’s health-care team. This plan will include which area to treat, how much radiation to give and how to best aim the radiation at the target. If your child has imaging on the day of the procedure, your child will remain under general anesthetic during the planning process and will be monitored by the anesthesia team in the area near the treatment unit.
What happens during treatment?
During treatment, your child will be moved from a stretcher to the treatment bed. They will continue to remain under general anesthesia. Your child will not feel the radiation and will not hear noise from the treatment unit. During the procedure, they may be moved in and out of the treatment unit several times to avoid being exposed to unnecessary radiation. The radiation therapist may also have to adjust the position of your child’s head frame throughout the procedure.
What to expect after treatment?
After the procedure, your child’s head frame will be removed and the pin sites on their forehead will be covered with small bandages. It is important that the pin sites do not get wet for the next 24 hours.
Your child will be woken up by the anesthesia team and will be monitored until fully awake.
Your child may get a headache or minor swelling where the frame was attached. Some pain medication will be provided to them, if needed.
Care after imaging
If your child had pre-procedural cerebral angiography performed through the groin, your child should remain on their back with their leg kept straight after treatment. Some pressure may be applied at the insertion site in the groin if further bleeding occurs. Slow ambulation can begin after four hours if there are no concerns at the accessed groin site, and your child may go home six hours after the procedure.
For information on how to care for your child after cerebral angiography, please see Angiography through the femoral artery (groin): Caring for your child at home after the procedure.
At SickKids
If your child requires stereotactic radiosurgery, they will have a clinic visit with the neurosurgeon at SickKids before being referred to the University Health Network (UHN) for the procedure. Your child will also have a clinic visit at the UHN prior to the procedure. After the procedure, your child may be transferred back to SickKids for monitoring.
For more information on the procedure at UHN see What to expect when getting radiosurgery on the Gamma Knife Treatment Unit (Using a Frame).
