Childhood leukemia

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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.

Radiation therapy is given for different reasons. Your child may have radiation therapy to:

  • prevent or treat the spread of leukemia to the brain and spinal cord (called the central nervous system, or CNS)
  • prevent or treat the spread of leukemia to the testicles
  • prepare for a stem cell transplant

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

External beam radiation therapy

During external beam radiation therapy, a machine directs radiation to the tumour and some of the surrounding tissue. 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, or 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 younger than 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 the preparation for a stem cell transplant. This is called total body irradiation (TBI).

Questions to ask about radiation therapy

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


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