Types of Treatment
Acute lymphoblastic leukemia is a cancer of the blood, so treatment is systemic, meaning it affects the entire body. At the time of diagnosis, the healthcare team will insert a central line to provide treatment. Chemotherapy is the mainstay of treatment.
The first phase of treatment usually lasts four weeks. Children receive three or four drugs by mouth, intravenously (into a vein), or into the spinal fluid (intrathecal delivery). The combination of drugs can vary depending on the particular diagnosis. The goal of this phase is to kill the leukemia cells and allow normal blood cells to return.
A bone marrow aspirate is performed at the end of this phase. The bone marrow is examined under a microscope. Often after the first round of chemotherapy, doctors will see no evidence of leukemia cells in the bone marrow. At that point, the disease is considered in remission. However, it is crucial to continue treatment, since there may be some cancer cells left over in the bone marrow or blood that could continue to replicate and allow the cancer to spread. However, remission is a very important first step on the road towards being cured. Nearly 98 of every 100 children with acute lymphoblastic leukemia will enter remission at the end of the first month of treatment.
The second phase of treatment lasts from 12-16 weeks. Different drugs from those used during Induction are given by mouth and intravenously.
The purpose of the consolidation phase is to kill leukemia cells that may remain after the drugs used in induction. Another main focus is on treating and preventing the growth of leukemia cells within the central nervous system (CNS prophylaxis). To accomplish this, spinal taps with intrathecal chemotherapy (directly into the spinal fluid) are performed weekly. In most cases, part of the consolidation phase will include treatment with the chemotherapy drug methotrexate.
This eight-week phase of treatment will include the use of the chemotherapy agent methotrexate. Methotrexate is given intravenously, either at lower doses in the clinic or at higher doses that require a 2-3 day stay in the hospital.