Radiation therapy for salivary gland cancer
Radiation therapy uses high-energy rays or particles to destroy cancer cells. Most people with salivary gland cancer have radiation therapy. 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 sometimes used as part of chemoradiation to treat salivary gland cancer. Chemoradiation is treatment in which chemotherapy is given during the same time period as radiation therapy.
When radiation therapy is offered
Radiation therapy is given for different reasons. You may have radiation therapy alone or as part of chemoradiation to:
- destroy cancer cells left behind after surgery and lower the risk of the cancer recurring (called adjuvant therapy)
- treat a tumour that can’t be reached or safely removed with surgery
- treat a tumour if you’re not well enough for, or you don’t want to have, surgery
- relieve pain or control the symptoms of advanced salivary gland cancer (called palliative therapy)
Radiation therapy alone or as part of chemoradiation may be offered after surgery:
- if the tumour couldn’t be completely removed
- if there are cancer cells in the edges of the tissue removed during surgery
- for intermediate-grade and high-grade tumours
- for large tumours
- for tumours that have spread to the bone, nerves, lymph vessels, lymph nodes or blood vessels
You may also have radiation to the lymph nodes in your neck if you have:
- a high-grade, aggressive type of tumour that tends to spread to lymph nodes in the neck
- cancer that has spread to more than one lymph node
- cancer that has spread into tissues around the lymph nodes
Before radiation therapy
Your radiation team will plan your radiation therapy treatment carefully. They try to make sure that the radiation beams are directed where the most radiation is needed. They also try to protect the surrounding tissues as much as possible from the effects of radiation. In some cases, surgery may be done to temporarily move a salivary gland out of the treatment area. It is moved back when radiation therapy is done. This is called a salivary gland transfer.
Before radiation therapy starts, you should have a dental checkup to make sure that your teeth, mouth and gums are healthy. This is because radiation therapy for salivary gland cancer can affect the mouth and teeth. If you need dental work, such as getting fillings and fixing or removing loose teeth, get it done before you have radiation therapy.
External beam radiation therapy
The type of radiation therapy most commonly used to treat salivary gland cancer is external beam radiation therapy. Radiation treatments are usually done 5 days a week for 6 or 7 weeks. Your treatment may be shorter if you are having radiation therapy only to relieve symptoms like pain or bleeding.
Conformal radiation therapy is a type of external beam radiation therapy that uses a special machine to direct the radiation beams to the shape of the area being treated. There are 2 main types of conformal radiation therapy used with salivary gland cancer.
Intensity-modulated radiation therapy (IMRT) delivers radiation beams at different intensities to different parts of the treatment area. A machine shapes the radiation beams very precisely, which can help spare the surrounding tissues from radiation. This type of radiation therapy is most often used for salivary gland cancer.
3-dimensional conformal radiation therapy (3-D CRT) shapes and aims the radiation beams from several different directions. All the beams are the same strength, or intensity. This is not used as often, as IMRT has been shown to be more precise at treating salivary gland tumours.
Side effects can happen with any type of treatment for salivary gland cancer, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all.
During radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. But damage to healthy cells can happen and may cause side effects. Side effects can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.
Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation and the treatment schedule. Some common side effects of radiation therapy used for salivary gland cancer are:
- skin problems
- dry mouth
- difficulty swallowing
- changes in taste
- tooth decay
- hearing problems or hearing loss
Tell your healthcare team if you have these side effects or others you think might be from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.
Questions to ask about radiation therapy
A tube through which lymph fluid travels in the body.
What’s the lifetime risk of getting cancer?
The latest Canadian Cancer Statistics report shows about half of Canadians are expected to be diagnosed with cancer in their lifetime.