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Radiation therapy for bone cancer
Radiation therapy uses high-energy rays or particles to destroy cancer cells. Most people with bone 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 given for different reasons. You may have radiation therapy to:
- shrink a tumour before surgery (called neoadjuvant therapy)
- destroy cancer cells left behind after surgery to reduce the risk that the cancer will come back (called adjuvant therapy)
- treat a bone tumour that can’t be removed with surgery (is unresectable)
- relieve pain or control the symptoms of advanced bone cancer (called palliative therapy)
The following types of radiation therapy are most commonly used to treat bone 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. The radiation therapy team will choose the size of the treatment area based on the size of the tumour and a margin of normal tissue around it. Radiation therapy is usually given in small daily doses (called fractions) over a period of 4 to 5 weeks.
Doctors may use the following types of external beam radiation therapy to treat a very specific area and spare as much of the surrounding normal tissue as possible.
Intensity-modulated radiation therapy (IMRT) delivers radiation to the tumour from many different angles. IMRT lets the radiation oncologist change the shape and strength of each radiation beam to the area of the tumour. A higher dose can be given to the tumour while the normal tissues near the tumour get less radiation. IMRT can be useful for treating bone tumours in hard-to-reach areas like the skull, spine or pelvis.
Conformal proton beam radiation therapy is a newer way of giving radiation. It uses proton beams instead of x-ray beams. X-ray beams release energy before and after they hit their target. Protons only release energy after reaching a certain distance. This means that protons cause less damage to the normal tissues they go through before reaching the tumour. This treatment is useful for treating bone tumours in hard-to-reach areas such as near the spinal cord or brain.
Right now, there are no conformal proton beam radiation therapy machines in Canada. People who need this treatment have to go to cancer treatment centres in the US that have these machines.
Stereotactic radiosurgery gives very high doses of radiation, in a small number of sessions, to a very specific area where cancer is found. It may be used to treat bone cancer that has spread to the brain or the lungs. Stereotactic radiosurgery may be available in some centres in Canada.
Side effects can happen with any type of treatment for bone 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. If you develop side effects, they 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 bone cancer are:
- loss of appetite
- skin reactions in the area being treated, such as dry skin or redness
- low blood cell counts
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
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.