There are 2 main ways radiation is used to treat cancer

  1. The most common way is using x-rays called external radiation. This is when radiation is directed from outside the body to an area inside the body.
  2. The other way to deliver radiation is with internal radiation. This treatment involves placing radiation sources inside the body to treat cancer.

Some patients may have both internal and external radiation treatments.

How Is Radiation Used To Treat Cancer?

  • Radiation places energy in the cells of your body using high-energy x rays.
  • The energy from the radiation will damage or destroy the cells along its path.
  • The radiation must pass through and come close to normal healthy tissue in order to reach the affected cells that may be present
  • The amount of radiation that your healthy tissues receive is kept as low as possible.

Preparing for Radiation Treatment

Most patients will need a planning CT scan to develop their treatment area. Micro tattoos will be placed on your skin during your planning appointment. These tattoos will help the therapists place you in the same position for your treatment each day. 

Before your first radiation treatment, a radiation therapist will provide you with education, so you will understand exactly what to expect throughout your treatments.

In preparation for radiation therapy, you may have a planning CT Scan.
Watch this video for more information about your scan:


You may be treated daily (Monday to Friday) for many days or weeks, depending on your individual treatment plan.

Your Radiation Treatment

Each daily treatment may take 15-45 minutes. Your appointment includes the time it takes to place you for your treatment and to provide the treatment. You will not feel anything during your treatments. 

You are alone in the room when the treatment is being given. There is an intercom system that will allow you to speak to the therapists if needed. There is a monitor so that the therapists can see you at all times.

Review Visits

You will see your radiation doctor and nurse each week during your treatment. They will monitor you throughout treatment and help you manage any side effects. Your weekly review is your chance to ask any questions to your Radiation Oncologist.

Additional visits with your doctor and nurse can be organized if you have urgent problems between your review visits. It is important that you notify the radiation therapists as early in the day as you can if there is a problem related to your treatment. They will organize a time for you to be seen if needed. Your appointment card will show you the day you are booked for your review session.

If you would like to learn more about radiation therapy treatment, please view this educational video: