Radiation therapy uses high-energy rays (or particles) to destroy cancer cells. To treat Hodgkin disease, a carefully focused beam of radiation is delivered from a machine outside the body. This is known as external beam radiation.
Most often, radiation treatments are given 5 days a week for several weeks. Before the treatments start, the radiation team takes careful measurements to determine the dose needed and the correct angles for aiming the radiation beams. Each treatment is much like getting an x-ray, but the radiation is stronger. Each treatment lasts only a few minutes, although the setup time – getting you or your child into place – usually takes longer. The treatment is painless, but some younger children might still need to be sedated to make sure they don’t move during the treatment.
Radiation therapy is most useful when Hodgkin disease is only in one part of the body. For classic Hodgkin disease, radiation is often given after chemotherapy, especially when there is a large or bulky tumor mass (usually in the chest). Chemotherapy or radiation alone would probably not cure the disease, but both treatments together usually get rid of it. Radiation therapy can also be used by itself to treat some cases of nodular lymphocyte predominant Hodgkin disease.
Radiation therapy is often very good at killing Hodgkin disease cells. But over the years as it has become clear that chemotherapy is also effective, doctors have used less radiation because of the possible long-lasting side effects. Modern imaging tests can also pinpoint the sites of Hodgkin disease more precisely, which helps doctors aim the radiation only at the disease itself. Today, if radiation therapy is used, only the involved areas are treated with radiation to try to limit the side effects.
Involved site radiation therapy (ISRT)
Many doctors prefer this newer form of radiation therapy when treating Hodgkin disease. The radiation is aimed only at the lymph nodes that originally contained Hodgkin disease, as well as any nearby areas it extended into. This helps spare nearby normal tissues from getting radiation.
Involved field radiation therapy (IFRT)
This was the preferred form of radiation therapy for Hodgkin disease until recently, but it is now largely being replaced by ISRT. In this technique, only the lymph node regions that have Hodgkin disease are treated, but this includes larger treatment areas than ISRT does (which might expose some nearby organs to radiation).
Extended field radiation
In the past, radiation was given to the major lymph node areas that contained Hodgkin disease, as well as the surrounding “normal” lymph node areas, just in case the Hodgkin disease had spread, even though the doctors could not actually detect it in these areas. This is called extended field radiation.
- If the Hodgkin disease was in the upper body, radiation was given to the mantle field, which included lymph node areas in the neck, chest, and under the arms. Sometimes this was extended to also include lymph nodes in the upper abdomen.
- Inverted Y field radiation therapy included the lymph nodes in the upper abdomen, the spleen, and the lymph nodes in the pelvis).
- When inverted Y field radiation was given together with mantle field radiation, the combination was called total nodal irradiation.
Because nearly all patients with Hodgkin disease are now treated with chemotherapy, extended field radiation is seldom used any more.
Total body irradiation
People who are getting a stem cell transplant may get radiation to the whole body along with high-dose chemotherapy, to try to kill lymphoma cells throughout the body. For more information on this procedure, see “High-dose chemotherapy and stem cell transplant.”
Possible side effects
The side effects of radiation therapy depend on where the radiation is aimed.
Short-term side effects: Some possible temporary effects include:
- Skin changes similar to sunburn in the areas getting radiation
- Feeling tired
- Dry mouth
Radiation given to several areas, especially after chemotherapy, can lower blood cell counts and increase the risk of infections.
Long-term side effects: Radiation therapy can also have long-lasting effects. The most serious of these is the increased risk of another cancer in the part of the body that was exposed to radiation.
Radiation to the chest or neck can damage the thyroid gland, which can affect its ability to make thyroid hormone. This can lead to fatigue and weight gain. Treatment with thyroid hormone pills can help with this.
Radiation to the chest also increases the risk of heart disease (such as heart attacks) and lung problems, while radiation to the neck may increase the risk of stroke many years later.
In children, radiation that reaches the bones may slow their growth. Depending on where the radiation is given, this could result in deformities or a lack of growth to full height. Radiation to the lower part of the body in children and young adults might also affect fertility later in life.
To reduce the risk of side effects, doctors carefully calculate the exact dose of radiation needed and aim the radiation beams as accurately as they can. Shields might also be placed over nearby parts of the body to protect them from the radiation. In girls and young women, the ovaries might be moved out of the way with minor surgery before radiation is given to help preserve fertility.
For more information about long-lasting side effects, see “What happens after treatment for Hodgkin disease?” If you or your child is getting radiation therapy, ask your doctor about the possible long-term side effects.
To learn more about radiation therapy, see the Radiation Therapy section of our website or Understanding Radiation Therapy: A Guide for Patients and Families.
Last Revised: 02/09/2016