Radiation therapy (radiotherapy), also called "irradiation," may be used to treat blood cancers (leukemia, lymphoma, myeloma or myelodysplastic syndromes). The type of radiation (called "ionizing radiation") that is used for radiotherapy is the same type that is used for diagnostic x-rays, but radiotherapy is given in higher doses.
Radiotherapy works by damaging the genetic material (DNA) within cells, which prevents the cells from growing and reproducing. Although the radiotherapy is directed at cancer cells, healthy cells near the cancer cells may also be damaged. However, a goal of radiotherapy is to protect the healthy cells as much as possible, so that the benefit (destroying the cancer cells) outweighs the risk (harming healthy cells).
Some Types of Radiotherapy Used to Treat Blood Cancers |
External beam radiation | External beam radiation is the type used most often when radiotherapy is appropriate to treat a patient with a blood cancer. A focused beam of radiation is delivered outside the body by a machine called a "linear accelerator" or "linac." The linear accelerator can move around the body to deliver radiation from various angles. Linear accelerators make it possible to decrease or avoid skin reactions and make the delivery of radiation more focused, so that there is less "scatter" of radiation to nearby tissues. External beam radiation does not make a patient "radioactive." |
Radioimmunotherapy | With radioimmunotherapy, a radioactive molecule is attached to a monoclonal antibody to target certain types of cancer cells. |
When radiotherapy is used for blood cancer treatment, it is usually part of a treatment plan that includes drug therapy. Radiotherapy may be used to relieve pain or discomfort caused by an enlarged liver, lymph node(s) or spleen.
Radiotherapy, either alone or with chemotherapy, is sometimes given as conditioning treatment to prepare a patient for a blood or marrow stem cell transplant.
Some Examples of Radiotherapy for Blood Cancers |
The dose (the total amount) of radiation used during treatment depends on various factors about the patient, the disease and reason for treatment. A radiation oncologist (a physician who specializes in using radiation to treat cancer) establishes the dose. Radiotherapy may be delivered to the patient during a series of visits, spread over several weeks (from two to 10 weeks, on average). This approach minimizes side effects and is called "dose fractionation." |
Disease | Example |
CTCL | Electron beam radiotherapy may be used to treat some cutaneous T-cell lymphoma (CTCL) patients |
Myeloma | Electron beam radiotherapy may be used to treat a plasmacytoma, a localized mass of myeloma cells in bone or other tissues of the body. |
ALL | Electron beam radiotherapy may be used to prevent or treat central nervous system (CNS) ALL for patients with acute lymphocytic leukemia (ALL). |
B-cell lymphomas | Electron beam radiotherapy can be used along with chemotherapy to treat large masses of lymphoma cells. Radioimmunotherapy may be used to treat some patients with certain types of B-cell lymphomas. |
Hodgkin Lymphoma | Electron beam radiotherapy may be added to drug therapy to shrink large lymphoma masses ("bulky" disease). |
What to Expect Before, During and After Radiotherapy
Simulation. Patients are prepared for radiotherapy by undergoing a "simulation" to determine the most effective ways to direct the radiation and position the patient during treatment.
For the simulation, members of the radiation oncology team measure the patient's body and they may mark the patient's skin so that the radiation is aimed at the same part of the body during each treatment session. These marks are small dots that are usually made with semi-permanent ink. A patient may choose to have the marks removed (by surgery or laser treatment) after radiotherapy is over. However, some physicians encourage patients to keep the marks to show the exact site(s) of initial therapy in the event that additional radiotherapy is necessary in the future.
Instead of marking the skin, a radiation therapist may mark an immobilization device—a mold, cast or similar object—which is used to help the patient remain still during the treatment sessions.
Treatment. External beam radiation does not cause pain or discomfort during a treatment session. However, it may be necessary to stay in one position for several minutes during a treatment session and this may be uncomfortable for some patients. Shields are used to protect certain parts of the body from radiation. For example, whenever possible, the testes or ovaries are shielded. Patients may be in the treatment area for 20 to 30 minutes although the actual radiation exposure may only take a few minutes.
During the treatment session staff members leave the room and stand behind a protective barrier so that they are not repeatedly exposed to radiation. They are within hearing distance of the patient and can maintain visual contact through a window or by using a closed-circuit television camera. Patients can talk to the staff during the treatment and report any discomfort or special needs.
It is also important for patients to talk to members of their radiation oncology team about any discomfort experienced in between treatment sessions. It may be necessary to make changes in the treatment that will benefit the patient.
Side Effects. The specific effects or radiotherapy that may occur depend on the dosage, location, and duration of the radiation. Most side effects gradually go away after treatment is finished. Some people will have no side effects or only very mild ones.
Side effects that may occur include
For more information on side effects, see the LLS booklets, Understanding Drug Therapy and Managing Side Effects and/or Blood and Marrow Stem Cell Transplantation.
Long-Term and Late Effects. Radiotherapy can cause side effects, long-term effects and "late effects" (effects that become apparent months or years after treatment has ended), including infertility. It is important for patients to discuss the chances of long-term or late effects with members of their oncology team before treatment begins. For example, there may be some options for fertility preservation that have to be discussed before treatment begins. You can read more about long-term and late effects in the LLS fact sheets, Long-term and Late Effects of Treatment for Childhood Leukemia or Lymphoma and Long-term and Late Effects of Treatment in Adults.
Follow Up. During and after radiotherapy patients need to get plenty of rest and follow a nutritious diet. Eating well during and after cancer therapy helps people to cope with side effects, fight infection, rebuild healthy tissue and maintain body weight and energy. A patient also needs to follow his or her physician's advice about caring for the areas of skin that were exposed to radiation. In order to help damaged skin heal, patients may be advised to
Shower or bathe with warm water
Protect the damaged area from the sun
Wear loose clothes
Get medical guidance before using skin care products on the affected area(s).
To cope with side effects such as fatigue, patients may want to seek support from family, friends, other patients who have had similar treatment and healthcare professionals. For more information, see the LLS booklets, Coping: Support for People Living with Leukemia, Lymphoma and Myeloma and Each New Day.
Clinical Trials
Clinical trials explore new drugs, new treatment-combinations. including the use of radiation therapy. or new uses for approved drugs for blood cancers and other diseases. New drugs and new combinations of therapies are needed to improve outcomes and find cures. Some goals of clinical trials involving radiotherapy may be to
Evaluate the optimal dosage or the best delivery method for radiotherapy
Study targeted agents that make use of radiotherapy (radioimmunotherapy)
Determine its effectiveness in combination with chemotherapy, targeted drug therapy or other treatments
Explore drugs that make cancer cells more sensitive to radiation therapy
Develop drugs or techniques that further protect healthy cells from the damaging effects of radiotherapy
Identify ways to prevent, minimize or treat commonly associated side effects, long-term or late effects of radiotherapy.
For More Information
OncoLink - Radiation Oncology
Information on different types of cancer, various treatment options and research advances. For information on radiotherapy, go to the OncoLink and enter "radiotherapy" in the search box.
National Cancer Institute
Helpful information on all aspects of cancer. NCI has facts sheets and a book on radiotherapy ("Radiation Therapy and You: Support for People with Cancer.") Go to the NCI website and enter "radiotherapy" in the search box to see these materials online.
RT Answers
The patient website of the American Society for Radiation Oncology (ASTRO)
provides information on how radiotherapy is used to treat cancer.
American College of Radiology White Paper on Radiation Dose in Medicine
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