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Radiation therapy uses high-energy rays or particles to kill
cancer cells. Osteosarcoma cells are not easily killed by radiation, so
radiation therapy does not play a major role in treating this disease.
External beam
radiation therapy is the type of radiation therapy most
often used as a treatment for osteosarcoma. It is much like getting an
x-ray, but the radiation is more intense. The procedure itself is
painless.
Before treatments start, the radiation team takes careful
measurements with imaging tests to determine the correct angles for
aiming the radiation beams and the proper dose of radiation.
Each actual treatment lasts only a few minutes, although the
setup time -- getting you (or your child) into place for treatment --
usually takes longer. Young children may be given medicine to make them
fall asleep so they will not move during the treatment. Most often,
radiation treatments are given 5 days a week for several weeks.
Radiation therapy may be useful in some cases where the tumor
cannot be completely removed by surgery. For example, osteosarcoma can
start in pelvic bones or in the bones of the face, particularly the
jaw. In these situations, it is often not possible to completely remove
the cancer. As much as possible is removed, and then radiation is given
to try to kill the remaining cancer. Chemotherapy may be used after
radiation.
Radiation can also be helpful in controlling symptoms like
pain and swelling if the cancer has come back or surgery is not
possible.
Bone-seeking radioactive drugs, such as samarium-153, are also
sometimes used to treat symptoms such as pain in people with advanced
osteosarcoma. They are injected into a vein and collect in bones. Once
there, the radiation they give off kills the cancer cells and relieves
some of the pain caused by bone metastases.
These drugs are especially helpful when cancer has spread to
many bones, since external beam radiation would need to be aimed at
each affected bone. In some cases, these drugs are used together with
external beam radiation aimed at the most painful bone metastases.
The major side effect of these drugs is a lowering of blood
cell counts, which could increase the risk for infections or bleeding,
especially if the blood counts are already low.
For more detailed information on radiation therapy, see Understanding Radiation Therapy:
A Guide for Patients and Families.
Last Medical Review: 01/14/2009
Last Revised: 01/14/2009
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