Leukemia--Acute Myeloid (Myelogenous) Overview

+ -Text Size

Treating Leukemia - Acute Myeloid (AML) TOPICS

Radiation therapy for acute myeloid leukemia

Radiation treatment is the use of high-energy x-rays to kill cancer cells. It is not often part of the main treatment for people with acute myeloid leukemia (AML). There are a few times in which radiation may be used to help treat leukemia:

  • It is sometimes used to treat leukemia that has spread to the brain and spinal fluid or to the testicles.
  • Radiation to the whole body is often an important part of treatment before a stem cell transplant.
  • It is used (rarely) to help shrink a tumor if it is pressing on the windpipe and causing breathing problems. But chemo is often used instead since it may work more quickly.
  • Radiation can also be used to reduce pain in a bone that has leukemia in it, if chemo hasn't helped.

The possible side effects of radiation depend on where the radiation is aimed. Sunburn-like skin changes in the treated area can happen. Radiation to the belly (abdomen) can sometimes cause nausea, vomiting, or diarrhea. If large areas of the body get radiation, the effects may include tiredness and an increased risk of infection.

For more information about radiation therapy, see our document Understanding Radiation Therapy: A Guide for Patients and Families.

Bone marrow or peripheral blood stem cell transplant for acute myeloid leukemia

Very high doses of chemo drugs might work better to kill cancer cells, but the damage to the bone marrow could be fatal. A stem cell transplant (SCT) offers a way for doctors to use high doses of chemo. The drugs destroy the patient's bone marrow, but the transplanted stem cells restore it.

Stem cells for a transplant come from either from the blood or from the bone marrow. Bone marrow transplants were more common in the past, but today peripheral blood stem cell transplant (PBSCT) is much more common.

There are 2 main types of stem cell transplants: allogeneic and autologous. The difference is the source of the blood-forming stem cells.

  • An allogeneic transplant is the most common form of SCT used to treat acute leukemia. For this, the stem cells come from someone else -- a donor whose tissue matches the patient's -- often a close relative, like a brother or sister. Sometimes umbilical cord stem cells are used.
  • In an autologous transplant, a patient's own stem cells are removed from bone marrow or blood. They are frozen and stored while the person gets strong chemo and perhaps radiation. The stem cells are then given back to the patient after treatment.

There is a good reason to use stem cells from someone else for the transplant. These cells seem to help fight any remaining leukemia cells through an immune reaction. This is called a graft-versus-leukemia reaction and is explained below. Also, the patient’s own stem cells may contain some leukemia cells, even if they are collected when the leukemia is in remission.

The transplant process

The treatment works like this: stem cells are collected from the bloodstream in a process called apheresis. The cells are frozen and stored. Patients are then given very high doses of chemo to kill the cancer cells. They also may get total body radiation to kill any remaining cancer cells. After treatment, the stored stem cells are given to the patient as a blood transfusion. The stem cells settle into the patient's bone marrow over the next several days and start to grow and make new blood cells.

People who get a donor's stem cells are given drugs to prevent rejection as well as other medicines as needed to prevent infections. Usually, stem cells start making new white blood cells within a couple of weeks after they are given. Then they begin making platelets, and finally, red blood cells.

Patients having SCT have to be kept away from germs as much as possible until their white blood cell count is at a safe level. They stay in the hospital until the white cell count reaches a certain number, usually around 1,000. After they go home, they will be seen in the outpatient clinic almost every day for several weeks.

Mini-transplant

Most older patients can't have a regular transplant that uses high doses of chemo. Some may be able to have what is called a mini-transplant (also called a non-myeloablative transplant or reduced-intensity transplant), where they get lower doses of chemo and radiation that do not destroy the all cells in their bone marrow. They then are given the donor stem cells. These cells enter the body and form a new immune system, which sees the leukemia cells as foreign and attacks them (a graft-versus-leukemia effect). This is not the standard type of transplant used for AML, and some doctors still think of this approach as experimental in this disease.

Some things to keep in mind

Stem cell transplantation (SCT) is a complex treatment. If the doctors think that a person with leukemia might be helped by this treatment, it is important that it be done at a hospital where the staff has experience.

SCT can cost more than $100,000 and might mean a long hospital stay. Because certain types of SCT may be seen as “experimental” by insurance companies, they might not pay for it. You should find out what your insurance will cover and what you might have to pay before deciding on a transplant.

Side effects of stem cell transplant

Common side effects are much the same as those caused by any other type of chemo and can be severe. These include nausea and vomiting, mouth sores, and severe low blood counts. One of the most common and serious short-term effects is the greater risk of infection caused by low white blood cell counts. Antibiotics are often given to try to prevent this. Other side effects, like low red blood cell and platelet counts, often mean the patient will need transfusions.

Graft-versus-host disease (GVHD) is the main problem of a donor stem cell (allogeneic) transplant. It happens when the immune system of the patient is taken over by that of the donor. The donor immune system then starts to attack the patient's other tissues and organs. In severe cases, GVHD can be life-threatening.

Symptoms can include bad skin rashes with itching and severe diarrhea. The liver and lungs may also be damaged. The patient may also be very tired and have aching muscles. If bad enough, GVHD can be fatal. Drugs that weaken the immune system may be given to try to control it. The plus side of graft-versus-host disease is that the donor bone marrow usually kills any remaining leukemia cells. This is called the graft-versus-leukemia effect.

To learn more about stem cell transplants, see our document, Stem Cell Transplant (Peripheral Blood, Bone Marrow, and Cord Blood Transplants).


Last Medical Review: 06/27/2013
Last Revised: 02/07/2014