Radiation therapy for childhood leukemia
Radiation therapy uses high-energy radiation to kill cancer cells. It is not always needed
to treat leukemia, but it can be used in different situations:
· It is sometimes used to try to prevent or treat the spread of leukemia to the brain or
treat the testicles if they are involved by leukemia cells.
· It can be used (rarely) to treat a tumor that is pressing on the trachea (windpipe). But
chemotherapy is often used instead, as it may work more quickly.
· Radiation to the whole body is often an important part of treatment before a bone
marrow or peripheral blood stem cell transplant (see the section “High-dose
chemotherapy and stem cell transplant”).
External beam radiation therapy, in which a machine delivers a beam of radiation to a
specific part of the body, is the type of radiation used most often for childhood leukemia.
Before treatment starts, the radiation team will take careful body measurements to
determine the correct angles for aiming the radiation beams and the proper dose of
radiation.
The treatment itself is much like getting an x-ray, but the radiation is more intense. It is
painless, but some younger children may need to be sedated to make sure they don’t
move during the treatment. Each treatment lasts only a few minutes, although the setup
time – getting your child into place for treatment – usually takes longer.
Possible side effects of radiation
The possible short-term side effects depend on where the radiation is aimed. Sunburn-like
skin changes and hair loss in the treated area are possible. Radiation to the abdomen can
sometimes cause nausea, vomiting, or diarrhea. For radiation that includes large parts of
the body, the effects may include fatigue and an increased risk of infection.
Longer-term side effects are also possible and are described in the section “What happens
after treatment for childhood leukemia?”
More information on radiation therapy can be found in the Radiation Therapy section of
our website, or in our document Understanding Radiation Therapy: A Guide for Patients
and Families.
Chemotherapy for childhood leukemia
Chemotherapy (chemo) is the main treatment for nearly all childhood leukemias. This is
treatment with anti-cancer drugs that are given into a vein, into a muscle, into the
cerebrospinal fluid (CSF), or taken as pills. Except when given into the CSF, chemo
drugs enter the bloodstream and reach all areas of the body, making this treatment very
useful for cancers such as leukemia.
The treatment of leukemia uses combinations of several chemo drugs. Doctors give
chemo in cycles, with each period of treatment followed by a rest period to give the body
time to recover. In general, treatment for acute myeloid leukemia (AML) uses higher
doses of chemo over a shorter period of time (usually less than a year), and acute
lymphocytic leukemia (ALL) treatment uses lower doses of chemo over a longer period
of time (usually 2 to 3 years).
Some of the drugs used to treat childhood leukemia include:
· Vincristine (Oncovin)
· Daunorubicin, also known as daunomycin (Cerubidine)
· Doxorubicin (Adriamycin)
· Cytarabine, also known as cytosine arabinoside or ara-C (Cytosar)
· L-asparaginase (Elspar), PEG-L-asparaginase (pegaspargase, Oncaspar)
· Etoposide (VePesid, others)
· Teniposide (Vumon)
· 6-mercaptopurine (Purinethol)
· 6-thioguanine
· Methotrexate
· Mitoxantrone
· Cyclophosphamide (Cytoxan)
· Prednisone
· Dexamethasone (Decadron, others)
Children will probably get several of these drugs at different times during the course of
treatment, but they do not get all of them.