Radiation therapy for acute myeloid leukemia

Radiation therapy uses high-energy rays or particles to destroy cancer cells.

Radiation therapy is sometimes used to treat acute myeloid leukemia (AML). Your healthcare team will use what they know about the cancer and about your health to plan the type and amount of radiation, and when and how it is given.

You may have radiation therapy to:

• the brain (called total brain irradiation) to treat leukemia that has spread to the central nervous system (CNS)
• the testicles to treat leukemia that has spread to the testicles
• the whole body (called total body irradiation) to prepare for a stem cell transplant
• relieve pain if the leukemia has spread to an area of bone

During external radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it. External radiation therapy is also called external beam radiation therapy.

Doctors may use the following external radiation techniques to accurately target the area to be treated and spare as much surrounding normal tissue as possible.

3D conformal radiation therapy (3D-CRT) has many beams of radiation directed at the tumour. The radiation oncologist uses a CT scan or an MRI to map the exact location and shape of the tumour. The radiation beams are then shaped and aimed at the tumour from different directions to treat the tumour from all angles. Each individual beam is fairly weak and less likely to damage normal tissue. A higher dose of radiation is delivered where the beams meet at the tumour.

Intensity-modulated radiation therapy (IMRT) is similar to 3D-CRT in that it delivers radiation from many different angles to treat the entire tumour. In addition to shaping and aiming the radiation beams, IMRT allows the radiation oncologist to adjust the strength (intensity) of the individual beams. This reduces the dose of radiation reaching nearby normal tissue while allowing a higher dose to be delivered to the tumour. It is useful for treating tumours in hard-to-reach areas.

Side effects can happen with any type of treatment for AML, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all.

During radiation therapy, your healthcare team protects healthy cells in the treatment area as much as possible. Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation and the treatment schedule. Tell your healthcare team if you have side effects that you think are from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

These are common side effects of radiation therapy for AML:

• fatigue
• skin problems
• hair loss
• loss of appetite
• nausea and vomiting
• low blood cell counts (called bone marrow suppression)

Radiation therapy to the brain may also cause:

• sore mouth
• swallowing problems
• neurological changes (with symptoms including memory loss, speech problems, problems with balance and coordination)
• somnolence syndrome (a group of symptoms including drowsiness, confusion, lack of energy and headache)
• earaches or hearing problems

Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.