Radiation therapy, also known as “radiotherapy,” uses high energy x-rays or other types of radiation to kill cancer cells. While most blood cancers cannot be cured with radiation therapy alone, it may be combined other treatments such as chemotherapy, immunotherapy and stem cell transplantation. Radiation therapy may also be used to relieve symptoms of blood cancer and improve quality of life. For example, radiation therapy may be used to shrink an enlarged spleen, liver or lymph nodes. It may also be used to manage bone pain caused by cancer cells growing in the bone marrow.
External beam radiation therapy (EBRT) is the most common type of radiation therapy used to treat blood cancers. Radioimmunotherapy is also sometimes used to treat some types of blood cancers.
External Beam Radiation
External beam radiation therapy delivers radiation from a machine outside of the body to target cancer cells. The machine moves around the body to deliver radiation from various angles. The type and dose (total amount) of radiation used during treatment depends on the disease and goal of treatment. A radiation oncologist will determine the dose.
External beam radiation does not make you radioactive. You cannot expose others to radiation so it is safe to be in close contact with other people after a radiation treatment.
Types of Beams Used
- Photons: Photon radiation beams are used during x-ray imaging at a lower dose. Photon beams can travel deep into the body to reach the cancer, but the beams can also damage healthy tissues. Your treatment team will take steps to minimize damage. A machine called a “linear accelerator” (“linac” for short) delivers the photon beams.
- Electrons: Electrons are particles with a negative charge. Electron beams do not travel very far through the body so these beams are used to treat cancers on the skin or near the surface of the body. A linear accelerator is also used for this type or radiation therapy. This type of radiation therapy is often used to treat cutaneous T-cell lymphoma or other skin lesions.
- Protons: Protons are particles with a positive charge. Proton beam radiation can be more targeted than photon beam radiation. This helps to minimize radiation to healthy tissues and organs. This type of radiation therapy is newer and requires the use of a special machine called a “synchrotron” or “cyclotron.”
Treatments are typically done once a day, 5 days a week (Monday through Friday), for a period of 2 to 4 weeks.
Total Body Irradiation (TBI) may be used to prepare for a stem cell transplantation. During TBI, small doses of radiation are delivered to the entire body to destroy cancer cells throughout the body. Treatment is administered in several divided daily doses to minimize side effects. Treatments are usually given 1 to 3 times a day over 2 to 4 days immediately before transplantation.
You'll need to prepare for radiation therapy by undergoing a "simulation" so the technician can determine the most effective ways to direct the radiation and position you during treatment. The technician may use imaging, such as a CT scan, PET scan or MRI, as a guide.
Your treatment team may mark your skin to ensure the radiation is aimed at the same part of your body during each treatment. These marks are small dots usually made with semi-permanent ink. In some cases, small permanent tattoos may be used to mark your skin.
Instead of marking the skin, your treatment team may mark an immobilization device—a mold, cast, mask or similar object—used to help you stay still during treatment. Molds can be used around your body to support your arms and legs so that you are as comfortable as possible. If you are uncomfortable, let the members of your treatment team know.
You shouldn't feel any pain or discomfort during a treatment session. However, you may need to stay in one position for several minutes during a session, which may be uncomfortable. You'll likely spend about 30 minutes in the treatment area even though actual radiation exposure lasts only a few minutes.
When you receive the radiation, the treatment team leaves the room and stands behind a protective barrier to protect them from repeated exposure. They can still hear you and see you through a window or closed-circuit television camera. You can talk to them during the treatment.
In between sessions, let your treatment team know about any discomfort you experience so they can make changes if needed.
Some healthy tissue near the cancer cells may be damaged during the treatment, causing side effects. Most side effects are temporary and generally disappear over time once treatment has ended. However, some side effects may appear months or years later. These are called late effects. Ask your treatment team what to expect and how to manage side side effects.
Fatigue and skin changes, such as dryness, redness, itching blistering or peeling, in the area being treated are the most common side effects. Skin changes usually peak 2 weeks after the last treatment session and then begin to improve.
Other side effects depend on the area of the body being treated. For example, radiation to the head and neck may cause dry mouth, mouth sores, or difficulty swallowing. Radiation to the stomach and abdomen may cause nausea, cramps or diarrhea. Radiation to the pelvis may cause sexual dysfunction or affect fertility.
See LLS's free fact sheet External Beam Radiation Therapy for more on side effects.
Some side effects, known as “late effects,” may occur months or years after treatment ends. Depending on the area of the body treated, these can include:
- Skin discoloration, decreased elasticity
- Cognitive (thinking/memory) changes
- Dental problems, including tooth decay
- Hearing loss
- Less active thyroid gland
- Heart disease
- Secondary cancer (development of another cancer)
Talk to your healthcare team about your risk for late effects and how you will be monitored for them. Ask for a written plan.
Use the Survivorship Workbook to collect all the important information you need throughout diagnosis, treatment, follow-up care and long-term management of a blood cancer.
Caring for Your Skin
Follow your doctor's advice about caring for skin exposed to radiation. To help damaged skin heal:
- Shower or bathe with warm water and unscented soap.
- Ask your treatment team before sing any skincare products on the treatment area.
- Protect skin from the sun.
- Do not expose skin to extreme heat or cold, such as ice packs or heating pads.
- Do not pick or scratch at skin.
- Wear loose clothes.
- Use fragrance-free laundry detergent.
- OncoLink, "Radiation Oncology" - An overview of radiotherapy. The site also features information about different types of cancer, treatment options and research advances.
- National Cancer Institute, "Radiation Therapy and You: Support for People with Cancer" - Helpful information about radiation therapy and all aspects of cancer.
- RT Answers - The patient website of the American Society for Radiation Oncology (ASTRO) features information about radiation therapy and cancer.
- The Society of Nuclear Medicine (SNM) - Includes patient information about molecular imaging, radiation safety and procedures such as PET scan.
- Download or order The Leukemia & Lymphoma Society's free fact sheet, External Beam Radiation Therapy.
- Managing Side Effects