What is radiation therapy

Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiations to kill cancer cells and shrink tumours. At low doses, radiation is used in x-rays to see inside your body, as with x-rays of your teeth or broken bones.

At high doses, radiation kills cancer cells or slows down their growth by damaging their DNA.
Cancer cells whose DNA is damaged beyond repair stop replicating and die. Our body then breaks them down and removes them.

Depending on the pathology, it takes days or weeks of treatment before cancer cells are damaged enough for cancer cells to die. Then, cancer cells keep dying for weeks or months after radiation therapy ends.

There are two main types of radiation therapy, external beam and internal.

The type of radiation therapy that you may undergo depends on many factors, including:

  • The type of cancer
  • The size of the tumour
  • The tumour’s location in the body
  • How close the tumour is to normal tissues that are sensitive to radiation
  • Your general health and medical history
  • Whether you will have other types of cancer treatment
  • Other factors, such as your age and other medical conditions

External beam radiation therapy comes from a machine called a “Linac” or Linear Accelerator, which aims radiation at your cancer.
The machine is large and can move around you during treatment, sending radiation to a part of your body from many directions in order to concentrate them on the cancer.

External beam radiation therapy is a local treatment, which means it treats a specific part of your body. For example, if you have cancer in your lung, you will have radiation only to your chest, not to your whole body. This limits the type and severity of side effects when compared to other cancer treatments.

Internal radiation therapy is a treatment in which a source of radiation is put inside your body. The radiation source can be solid or liquid.

Internal radiation therapy with a solid source is called brachytherapy. In this type of treatment, seeds, ribbons, or capsules that contain a radiation source are placed in your body, in or near the tumour. Like external beam radiation therapy, brachytherapy is a local treatment and treats only a specific part of your body.

With brachytherapy, the radiation source in your body will give off radiation for a while.

For some people, radiation may be the only treatment you need. But, most often, you will have radiation therapy alongside other cancer treatments, such as surgery, chemotherapy, and immunotherapy. Radiation therapy may be given before, during, or after these other treatments to improve the chances that treatment will work. The timing of when radiation therapy is given depends on the type of cancer being treated and whether the goal of radiation therapy is to treat the cancer or ease symptoms.

External beam radiation therapy is used to treat many types of cancer, while brachytherapy is most often used to treat cancers of the head and neck, breast, cervix, prostate, and eye.

Depending on your condition, radiation therapy may last from 1 day to multiple weeks. Your doctor at Amethyst will elaborate a treatment plan tailored to your needs.

During treatment, you will be instructed by our staff on what to do. Consult our FAQs to know more about what to do during treatment, and always refer to our staff if you have further questions, they will be happy to help you.