Radiation therapy uses high-energy rays (or particles) to destroy cancer cells or slow their rate of growth. HD is usually treated with a carefully focused beam of radiation, delivered from a machine outside the body. This is known as external beam radiation. It is most useful when the disease is localized to one part of the body or is so bulky that even if chemotherapy is used, it won't get rid of all the cancer in the area.

Doctors have found that treating only the known areas of disease with radiation can produce a cure. This is called involved field radiation and is now the preferred form of radiation therapy. It is often combined with chemotherapy, although they are not given at the same time. After several courses of chemotherapy, involved field radiation will be given to areas that have clinically obvious disease.

Once, it was typical to treat the major site of disease and surrounding lymph node areas in case the HD had spread. This was called extended field radiation. Extended field radiation for HD in the upper body was given to the mantle field (the neck, chest, and lymph nodes under the arms). Sometimes this was extended to lymph nodes in the upper abdomen. When inverted Y field radiation therapy (to the lymph nodes in the upper abdomen, the spleen, and the lymph nodes in the pelvis) was given together with mantle field radiation, the combination was called total nodal radiation. These extensive radiation treatments are no longer used in children.

Side effects: The main drawback of external beam radiation is that the radiation can damage nearby healthy tissue. Some people have skin changes similar to sunburn, but it slowly fades away. Other possible temporary side effects include fatigue, nausea, or diarrhea.

Radiation therapy can have long-term side effects. The most serious of these is cancer. Women who received chest radiation before they were 30 years old have a higher risk of breast cancer. They should consider beginning mammogram testing at an early age.

Likewise, lung cancer risk is higher after chest radiation. This risk increases considerably in smokers.

Other less common side effects also depend on the dose and location of the therapy, as well as the age of the patient at the time of treatment, and should be discussed with your child’s doctor. If the ovaries or testicles receive radiation, then reduced fertility could be an effect. These side effects can be increased when treatment includes both chemotherapy and radiation therapy.

To reduce the risk of side effects, doctors carefully calculate the exact radiation dose needed and aim the beam as accurately as they can to hit the cancer. This requires a great deal of planning. As more clinical trials are being performed, doctors are learning they can use less radiation. Some studies have even shown that radiation can be eliminated altogether. But this is not yet accepted by all doctors who treat HD.

Autologous Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation

In some patients, HD becomes resistant to standard treatment with chemotherapy and radiation therapy. These patients may need higher doses of chemotherapy to treat the disease, but such doses would destroy the patient’s bone marrow (blood producing cells).

Autologous (taken from the patient and not a donor) stem cell transplantation is a newer type of treatment that allows for higher treatment doses to be given. It may be offered as part of a clinical trial or may be used outside a clinical trial.

Autologous bone marrow transplant: In this approach, the patient's own bone marrow is taken out and stored (frozen). Very high doses of chemotherapy, with or without radiation therapy, are then given to kill the cancer. These high doses of chemotherapy destroy bone marrow, too.

After the high-dose chemotherapy treatments, the stored marrow is thawed and given back through a vein where it enters the bloodstream and returns to the bone, replacing the marrow that was destroyed and the blood cells needed to fight infection and carry oxygen throughout the body.

Peripheral blood stem cell transplant: Another type of autologous transplant is called peripheral blood stem cell transplant (PBSCT). In the first step of this process, a machine removes the patient's blood a little at a time, takes out only the stem cells (immature cells from which all blood cells develop), and returns the rest of the blood to the body.

This procedure is called leukapheresis and usually takes a few hours. The collected stem cells are then frozen until after treatment, when they are returned to the patient. Peripheral blood has become the most common source of stem cells for autologous transplants.

The chances for recovery are greater if these transplant procedures take place in a hospital that has done many bone marrow transplantations.

As doctors have gained more experience with autologous stem cell transplants in HD, it has become clear that it is better to do these earlier in the course of treatment rather than later. If the first set of standard treatments for HD doesn't get rid of the cancer, then many doctors would recommend transplantation right away.

On the other hand, if HD comes back after it had gone away for a long time with the first treatment, most doctors would favor a second course of standard treatment. They would wait to see if the patient gets better with the standard treatment before recommending the transplant.

For more information on stem cell transplant see the ACS document "Bone Marrow & Peripheral Blood Stem Cell Transplants."

Revised 8-23-03