Canadian Cancer Society logo

Stomach cancer

You are here: 

Radiation therapy for stomach cancer

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used to treat stomach cancer. In most cases, radiation therapy is given with chemotherapy (chemoradiation). Your healthcare team will consider your personal needs to plan the type and amount of radiation and when and how it is given. You may also receive other treatments.

Radiation therapy is given for different reasons. You may have radiation therapy to:

  • destroy the cancer cells in the body
  • shrink a tumour before surgery, with or without chemotherapy (called neoadjuvant therapy)
  • destroy cancer cells left behind after surgery, and usually combined with chemotherapy, to reduce the risk of the cancer coming back, or recurring (called adjuvant therapy)
  • relieve pain or control the symptoms of advanced stomach cancer (called palliative therapy)

Radiation used as palliative therapy may help control bleeding from the tumour or shrink a tumour that is causing a blockage. Relieving the blockage may also help a person eat.

The following are the types of radiation therapy most commonly used to treat stomach cancer.

External beam radiation therapy

During external beam radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it. Radiation therapy for stomach cancer must be very carefully planned by the healthcare team. Several organs are close to the stomach, including the liver, small intestine, kidneys, spinal cord and heart. The high dose of radiation needed to treat stomach cancer could damage these organs. Special shields are made to protect the other organs in the area as much as possible. Conformal radiation therapy is often used to help protect surrounding organs.


Radiation therapy is sometimes given during the same time period as chemotherapy for stomach cancer. This is called chemoradiation. The type of radiation therapy usually given in combination with chemotherapy is external beam radiation therapy, and it’s most often given with 5-fluoruracil (Adrucil, 5-FU) and leucovorin (folinic acid). This combination helps make the cancer cells more sensitive to the effects of radiation therapy.

Questions to ask about radiation therapy

Find out more about radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.


Dr Steven Jones Using cancer genetics to guide personalized treatment

Read more

Support from someone who has ‘been there’

Illustration of conversation

The Canadian Cancer Society’s peer support program is a telephone support service that matches cancer patients and their caregivers with specially trained volunteers.

Learn more