Radiation Therapy for Osteosarcoma

Radiation therapy uses high-energy x-rays or other types of radiation to kill cancer cells. It can be given internally or externally:

• External beam radiation therapy (EBRT) - Radiation from a high-energy x-ray machine (linear accelerator) outside the body is focused on the cancer cells. EBRT can harm both the cancer cells and nearby healthy tissue. Most people are treated with EBRT for a few minutes 5 days a week for several weeks as an outpatient. EBRT is the most common kind of radiation therapy for osteosarcoma.
• Bone-seeking isotopes - A bone-seeking radioactive chemical, such as samarium-153, is injected into a vein. The chemical attaches to active areas of bone formation, including osteosarcoma. This treatment is useful for treating advanced disease and reducing pain.
• Internal radiation therapy (brachytherapy or interstitial radiation therapy) - Small pellets (or “seeds”) that contain radioactive materials are placed in your body in or near the tumor. The radioactive pellets release their radiation slowly over time. Brachytherapy lets the doctor use a higher dose of radiation than EBRT.

It is difficult to kill osteosarcoma cells with radiation, so radiation therapy is not usually used to treat the disease. However, it can be useful for patients with tumors that cannot be completely removed by surgery, such as tumors in the pelvic or facial bones. In these cases, the surgeon removes as much of the tumor as possible and then radiation is used to kill the cancer that is left. Radiation therapy is also useful for treating certain symptoms, such as pain and swelling, if the cancer has come back (recurred) after treatment.