Radiation Therapy for Non-Hodgkin Lymphoma

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used as part of treatment for non-Hodgkin lymphoma (NHL).

When is radiation therapy used for non-Hodgkin lymphoma?

Radiation therapy might be used:

• As the main treatment for some types of NHL if they are found early, in stage I or II.
• Along with chemotherapy for more advanced lymphomas and for some lymphomas that are more aggressive.
• To ease symptoms caused by lymphoma that has spread to organs such as the brain or spinal cord.
• To ease pain caused by a tumor pressing on nerves.

If you get a stem cell transplant as part of your NHL treatment, you may receive total body irradiation (TBI) along with high-dose chemotherapy as part of the conditioning regimen before your transplant. However, many transplant centers now use chemotherapy-only conditioning regimens. TBI is used less often than in the past.

What type of radiation is used for NHL?

When radiation is used to treat NHL, it’s most often done with a carefully focused beam of radiation delivered from a machine outside the body. This is known as external beam radiation.

There are several types of external beam radiation. Treatment for NHL most often uses photon-based techniques such as:

• Intensity-modulated radiation therapy (IMRT)
• Volumetric modulated arc therapy (VMAT)

Proton therapy may also be used in select cases, such as in children or when the tumor is near critical structures. This type of external beam radiation is not available at all centers.

For superficial tumors, such as skin lymphomas, doctors may use electron beams.  Electron beams are another type of external beam radiation that doesn't travel as far into the body.

How is radiation therapy given?

Radiation treatment is usually given 5 days a week for several weeks. Each treatment lasts only a few minutes, although it usually takes longer than this to get you into place for treatment.

The treatment is a lot like getting an x-ray, but the radiation is stronger. It does not hurt.

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. Because lymph nodes are all over your body, 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 non-Hodgkin lymphoma depend on where the radiation is aimed. These effects often go away shortly after treatment is finished, although some side effects can last long term.

Side effects tend to be worse if radiation and chemotherapy are given together.

Short-term side effects

Common short-term side effects include:

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

Some side effects depend on where the radiation is aimed:

• Nausea and diarrhea are more common if your abdomen (belly) is treated with radiation.
• When radiation is given to several areas, it can lower blood cell counts and increase the risk of infections. This is especially true if the radiation is given after chemotherapy.
• Radiation to the head and neck area can lead to mouth sores and trouble swallowing. Some people later have problems with dry mouth.

Long-term side effects

Long-term serious side effects are also possible.

• Radiation to the chest can damage your lungs, making it harder to breathe. It can also harm your heart and nearby blood vessels. This can raise the risk of heart attack, heart failure, and other heart problems, sometimes many years after treatment ends.
• Radiation to the neck can affect your thyroid gland. Your thyroid controls metabolism. If it’s damaged, it may not work as well. This can lead to fatigue and weight gain.
• Brain radiation can cause headaches, memory loss, personality changes, and trouble concentrating. These problems may not show up until 1 to 2 years after treatment.

In rare cases, a new cancer can develop in or near the area that received radiation. This sometimes happens many years later. Because of this, long-term follow-up with your healthcare team is important.