Radiation Therapy for Hodgkin Lymphoma

Radiation therapy is part of the treatment for most people with Hodgkin lymphoma. This type of treatment uses high-energy rays, or particles, to destroy cancer cells. It's especially useful when Hodgkin lymphoma is only in one part of the body.

When is radiation used to treat Hodgkin lymphoma?

Classic Hodgkin lymphoma (cHL)

Radiation therapy can be effective at killing Hodgkin lymphoma cells. The goal is to use lower doses of radiation because it can cause long-lasting side effects.

• Chemotherapy is often used alone, without radiation therapy, especially in younger people if the goal is to avoid radiation exposure.
• Treatment with a combination of chemotherapy and radiation can be very effective for certain people.
• Radiation can also be given after chemotherapy as part of treatment for cHL, especially when there is a large or bulky tumor mass (usually in the chest).

Nodular lymphocyte-predominant Hodgkin lymphoma (NHLPL) 

Radiation therapy can be used by itself to treat some cases of early-stage NHLPL.

What type of radiation is used for Hodgkin lymphoma?

To treat Hodgkin lymphoma, doctors use a machine to send strong beams of radiation to the cancer. This is called external beam radiation.

Involved site radiation therapy (ISRT)

Many doctors prefer this newer approach to radiation therapy when treating Hodgkin lymphoma. In ISRT, radiation is aimed only at the lymph nodes that originally contained lymphoma, as well as any nearby areas the cancer extended into.

This shrinks the size of the treatment area, or field. It helps spare nearby normal tissues and organs from getting radiation.

Involved field radiation therapy (IFRT)

This was the preferred form of radiation therapy for Hodgkin lymphoma in the past, but it's now largely being replaced by ISRT.

In this technique, only the lymph node regions that have Hodgkin lymphoma are treated, but this includes larger treatment areas than ISRT does. This can increase the risk of radiation reaching nearby organs.

How is radiation therapy given for Hodgkin lymphoma?

Radiation is usually given 5 days a week for a few weeks. Each session is quick. It is a lot like getting an x-ray, but with stronger radiation. The setup may take longer than the treatment itself. It doesn’t hurt, but young children might need medicine to help them stay still.

Before treatment starts: The care team does a planning session called a simulation. They use imaging tests like CT or PET scans to decide where to aim the radiation and how much to give.

During treatment: You may lie in a mold or use a headrest to help you stay in the same position each time. Sometimes you’ll be asked to hold your breath for a few seconds. This helps focus the radiation on the cancer and protect healthy body parts.

Keeping healthy organs safe: Modern imaging lets doctors target the lymphoma very accurately. This helps avoid harming nearby healthy organs like the lungs, heart, and spinal cord. Since lymph nodes are all over your body, Hodgkin lymphoma can grow near important organs, muscles, and nerves. It's very important to aim the radiation carefully.

Possible side effects of radiation therapy

The side effects of radiation therapy for Hodgkin lymphoma depend on where the radiation is aimed.

Short-term side effects

Some possible short-term effects include:

• Skin changes in areas getting radiation, ranging from redness to blistering and peeling
• Feeling tired
• Dry mouth
• Nausea
• Diarrhea

Radiation given to several areas, especially after chemotherapy, can lower blood cell counts and increase the risk of infections.

Long-term effects

Radiation therapy can also have long-lasting effects, including:

• An increased risk of another cancer in the part of the body exposed to radiation
• Damage to the thyroid gland from radiation to the chest or neck, which can affect its ability to make thyroid hormone and lead to fatigue and weight gain
• An increased risk of lung problems and heart disease, such as heart attacks, from radiation to the chest
• An increased risk of stroke years after radiation to the neck
• Slowed bone growth in children. Depending on where the radiation is given, this could cause deformities or prevent a child from growing to their full height.
• Radiation to the lower part of the body in children and young adults could also affect fertility later in life.

Reducing the risk of side effects

To reduce the risk of side effects, your cancer care team will carefully calculate the exact dose of radiation you need and aim the beams as accurately as possible. They might also place shields over nearby parts of the body to protect them from the radiation.

To help preserve fertility in girls and young women, the ovaries are sometimes moved out of the way with minor surgery before radiation.

If you or your child is getting radiation therapy, be sure to talk to your cancer care team about the possible long-term side effects. Hodgkin lymphoma can be cured, and long-term side effects are a very real concern.

For more information, see After Hodgkin Lymphoma Treatment.