Radiation for brain tumours

Radiation therapy may be used to help treat a brain tumour. Learn how radiation therapy works and what you need to know before your child begins treatment.

Key points

Radiation therapy is the use of high-energy X-rays, gamma rays, or particles to destroy tumour cells.
Before radiation begins, your child will have a special mask created and require a planning CT scan and possibly an MRI.
Radiation is not dangerous for family members or friends; your child is not "radioactive."
Side effects may include fatigue, excessive sleepiness, hair loss, nausea or vomiting, and headaches.

Introduction

About the treatment

Preparing for the treatment

Before radiation begins

You will meet with the radiation oncology treatment team. This radiation team will include the radiation oncologist, nurse coordinator, and radiation therapist. They will examine your child and explain the treatment to you. You will find out the schedule of treatments, and possible side effects.

Remember to bring a pen and paper, phone or laptop to write down any new information or questions you may have.

There are several steps before radiation therapy begins. These appointments take place at the radiation centre. Your child will need a mask made to help them stay still and in the same position during radiation. Once the mask is made, your child will have a planning computed tomography (CT) scan.

Your child may anticipate and fear the unknown of yet another new procedure. At times, this fear does not allow the child to cooperate, especially if they are very young. In these situations, it may be necessary for your child to have an anaesthetic for the planning session and daily treatments. However, if a child is adequately prepared for what to expect during the planning and treatment appointments, this will help to gain their cooperation and may avoid the need for anaesthesia in older children. Your radiation team, in collaboration with child life specialists, are valuable resources in preparing a child for radiation planning and treatments.

How is the mask made?

The plastic mask will be made by shaping warm plastic around your child’s face. To comfort your child, you may wish to bring a toy or blanket. You can prepare them the day before by placing warm, wet washcloths over their face in the bath. This is similar to the feeling of the plastic. Tell them what will happen while the mask is being made.

The material to make the mask starts out as a firm aerated plastic sheet. This sheet is placed in a warm water bath which will make it soft and pliable.
Your child will have to lay on the CT table while the soft plastic is placed on their face. The plastic feels wet, warm and weird, but it does not hurt.
When the plastic is hard and dry, it is ready to come off. The eyes and mouth are then cut out of the mask and placed back on for the planning CT.
If your child is having radiation to the whole head and spine, they will need tiny ink dots placed to help line up the spine for treatment. These ink dots are called tattoos.
When the treatment schedule is complete, your child may be able to bring the mask home.

What happens at the planning CT and MRI scan?

Your child will lay back on the CT table wearing their mask. The therapist will use a felt pen to make marks on the plastic mask. The purpose of the CT scan is to demonstrate the position your child will be in during treatment. This is not a diagnostic scan; it is used for planning and mapping the radiation treatment field to determine the exact field of radiation. The CT scan will take about five minutes. Some children will require a planning MRI as well. This MRI is also done at the radiation centre and usually takes 10-15 minutes.

Treatment

What happens during radiation therapy?

You and your child will have to visit the radiation centre every day from Monday to Friday for several weeks. The radiation team will give you a schedule.

Radiation treatment is like having an X-ray. There is no pain. This is what your child will experience:

Your child will lie down on a table and their mask will be put on their face.
The radiation therapist will make sure the marks on the mask line up with the machine settings. Your child will be in the room for about 30 minutes for set-up and treatment.
Your child will wear Velcro seat belts for safety.
Some centres have access to TV and DVD or Blu-ray players which your child can watch during treatment.
Once the child is ready, parents and therapists must leave the room.
You can see your child on a video TV monitor and you can speak to them.
Before starting the treatment, your child will have a mini scan to ensure they are in the correct position for the treatment based on the planning CT scan. Once the position is confirmed, the radiation treatment will begin. The machines may make clicking or whirring noises. The treatment will typically last less than five minutes. Most treatments are only one or two minutes. The treatment time depends on the radiation dose and the technique being used.

During treatment, the radiation nurse and radiation therapists will be available for any questions or concerns you may have. The radiation oncologist will see your child once a week to see how they are doing, and to talk about any concerns or questions you may have.

Is radiation therapy dangerous for family members or friends?

No, radiation is not dangerous for family members and friends. The radiation will only affect the person who is having the treatment. The radiation is a form of energy, like heat or light, that goes away very quickly when the energy source is removed. Your child is not "radioactive." They can go to school and see their friends.

How is radiation given?

Modern radiation techniques allow doctors to accurately focus radiation therapy to the area(s) of the brain requiring treatment. These radiation techniques are best described as conformal radiotherapy and include many different specific technologies. A computer simulation produces an accurate image of the tumour and nearby areas. Then, the radiation beams are shaped exactly to the contour of the tumour to reduce the dose of radiation to nearby normal tissue. Some techniques that may be used are described below.

Intensity-modulated radiation therapy (IMRT)

IMRT refers to a technique of being able to modify the intensity of each radiation beam in such a way as to be able to exclude some important parts of the brain (e.g., optic nerves, the brain stem, the pituitary gland) that are near the tumour, while still giving a full dose of radiation to the tumour.

Stereotactic radiosurgery

Stereotactic radiosurgery refers to the use of technology including stereotactic frames or specialized masks to help guide the radiation beams to smaller tumours. Your radiation oncologist will determine whether your child is a candidate for this treatment.

Proton radiation therapy

Proton therapy is a type of radiation therapy that uses proton particles rather than conventional X-rays to treat certain childhood cancers. Your radiation oncologist will discuss with you if your child may be a candidate for proton therapy and what the potential benefits may be. This therapy requires highly specialized equipment not yet available in Canada. Currently, eligible patients must travel outside of Canada to receive proton radiation therapy.

After the treatment

Last updated: M01 10th 2022