Radiation therapy for childhood leukemia

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used to treat childhood leukemia. The healthcare team will consider your child’s personal needs to plan the type and amount of radiation, and when and how it is given. Your child may also receive other treatments.

Radiation therapy is sometimes used to treat childhood leukemia, especially when it spreads to the brain or spinal cord (called the central nervous system, or CNS). Doctors usually use radiation therapy to treat leukemia only when it doesn’t respond to other treatments or has a very high risk of coming back.

The following types of radiation therapy are used to treat childhood leukemia.

External radiation therapy

During external radiation therapy (also called external beam radiation therapy), a machine directs radiation through the skin to the tumour and some of the tissue around it. The radiation therapy team will base the size of the treatment area on the amount of cancer present. Very young children may be sedated before radiation therapy to keep them still during treatment.

It may be used to prevent or treat the spread of leukemia to the CNS or testicles.

Children with acute lymphoblastic leukemia (ALL) may be given external beam radiation therapy when:

  • there are leukemia cells (blasts) in the cerebrospinal fluid (CSF) at diagnosis
  • they have T-cell ALL with a high white blood cell (WBC) count
  • there is a high risk that leukemia will spread to the CNS
  • there are leukemia cells in the testicles after induction chemotherapy

External beam radiation therapy is not commonly used to treat acute myelogenous leukemia (AML).

Young children, especially those under 4 years of age, have a higher risk of developing side effects from radiation therapy to the brain. Whenever possible, intrathecal and systemic chemotherapy (rather than radiation therapy) are used to prevent or treat the spread of leukemia to the brain.

External beam radiation may be given to the entire body as part of preparation for a stem cell transplant. This is called total body irradiation (TBI).

Side effects

Side effects can happen with any type of treatment for childhood leukemia, but every child’s experience is different. Some children have many side effects. Other children have only a few side effects.

During radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. But damage to healthy cells can happen and may cause side effects. Side effects can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

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, your child’s age and the treatment schedule.

Some common side effects of radiation therapy to the brain used for childhood leukemia are:

Some common side effects of radiation therapy to the testicles used for childhood leukemia are:

Other side effects can develop months or years after treatment for childhood leukemia. Find out more about late effects for childhood leukemia.

Tell your child’s healthcare team if your child has these side effects or others you think might be from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help your child deal with them.

Questions to ask about radiation therapy

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

Expert review and references

  • American Cancer Society. Childhood leukemia. Atlanta, GA: American Cancer Society; 2012.
  • American Society of Clinical Oncology . Leukemia - Acute Lymphoblastic - ALL - Childhood . 2017 : https://www.cancer.net/.
  • Kanwar, V. S. et al . Pediatric acute lymphoblastic leukemia. eMedicine.Medscape.com. WebMD LLC; 2012.
  • National Cancer Institute. Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment (PDQ®) Patient Version. 2018.

Medical disclaimer

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