Radiation therapy for non-Hodgkin lymphoma in children

Radiation therapy uses high-energy rays to kill cancer cells. Radiation therapy was once a very common treatment for children with non-Hodgkin lymphoma. But as doctors have developed more effective chemotherapy treatments, the use of radiation therapy has become much more limited.

Radiation focused on a cancer from a source outside the body is called external beam radiation. This is the type of radiation therapy most often used to treat non-Hodgkin lymphoma. The treatment is much like getting an x-ray, but the radiation is more intense. Before the treatments start, the radiation team takes careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. Each treatment lasts only a few minutes, although the setup time – getting your child into place for treatment – usually takes longer. The procedure itself is painless, but some younger children may need to be sedated to make sure they don't move during the treatment. Most often, radiation treatments are given 5 days a week for several weeks.

There are a few instances in which radiation therapy may be used.

• Sometimes radiation is used along with chemotherapy, such as in patients where the lymphoma has reached the brain or spinal cord.
• It may be used as a form of urgent treatment in children with symptoms caused by large tumors in the chest.
• It may be used as part of treatment for children receiving a bone marrow or peripheral blood stem cell transplant (see the section, “High-dose chemotherapy and stem cell transplant”).
• It can also be used to relieve symptoms caused by lymphoma in internal organs, such when it is causing pain because it is pressing on nerves.

Possible risks and side effects of radiation therapy

Short-term side effects of radiation therapy may include sunburn-like skin problems or hair loss in the area being treated. Radiation therapy that includes large parts of the body can cause fatigue. Radiation of the abdomen may cause nausea, vomiting, or diarrhea. Often these effects go away after a short while.

Possible long-term side effects of radiation therapy in children can be more serious, and may occur after many years.

• Chest radiation therapy may damage the lungs or heart, which could raise the risk of lung or heart problems later in life. In the long term, radiation to the chest may also increase the risk of lung cancer (especially in smokers) and of breast cancer.
• Side effects of radiation therapy to the brain usually become most serious 1 or 2 years after treatment and may include headaches and problems such as memory loss, personality changes, and trouble learning at school.
• Radiation to other parts of the body may slow their growth or increase the risks for certain other cancers, such as those of muscle or bone (called sarcomas) or of the digestive tract.

Because of these possible long-term effects, doctors try to avoid using radiation therapy in children or limit the doses used whenever possible.