High-Dose Chemotherapy/Radiation Therapy and Stem Cell Transplant for Neuroblastoma

This type of treatment is often used in children with high-risk neuroblastoma who are unlikely to be cured with other treatments.

Giving higher doses of chemotherapy (and sometimes radiation) might be more effective in treating these cancers, but normally this can’t be done because it would cause severe damage to the bone marrow, where new blood cells are made. This could lead to life-threatening shortages of blood cells.

Doctors can sometimes get around this problem by giving the high-dose treatments, then replacing the patient’s bone marrow cells by giving them new blood-making cells (called stem cells). This is known as a stem cell transplant (SCT).

In the past, the stem cells were often collected from the child’s own bone marrow before treatment, which required drilling small holes in certain bones. The treatment was commonly referred to as a bone marrow transplant.

But doctors have found that stem cells can be collected from the bloodstream during a procedure known as apheresis. This is similar to donating blood, but instead of going into a collecting bag, the blood goes into a special machine that filters out the stem cells and returns the other parts of the blood back to the person’s body. This process may be repeated over a few days. The stem cells are then frozen until the transplant.

How the transplant is done

Typically, the child will be admitted to the stem cell transplant unit of the hospital on the day before the high-dose chemo begins. He or she will usually stay in the hospital until after the chemo and the stem cells have been given, and until the stem cells have started making new blood cells again (see below).

The child gets high-dose chemotherapy, often along with radiation. This destroys the cancer cells in the body, as well as the normal cells in the bone marrow. After treatment, the frozen stem cells are thawed and given as a blood transfusion. The stem cells travel through the bloodstream and settle in the child’s bone marrow.

Usually within a couple of weeks, the stem cells begin making new white blood cells. This is later followed by new platelet production and new red blood cell production. Until this happens, the child is at high risk of infection because of a low white blood cell count, as well as bleeding because of a low platelet count. To help lower the risk of infection, the child stays in a special hospital room, and visitors must wear protective clothing. Blood and platelet transfusions and treatment with IV antibiotics may also be used to help prevent or treat infections or bleeding problems.

The child usually stays in the hospital room until part of the white blood cell count (known as the absolute neutrophil count, or ANC) rises to a safe level. The child is then seen in an outpatient clinic almost every day for several weeks. Because platelet counts often take longer to return to a safe level, the child may get platelet transfusions as an outpatient. Patients may need to make regular visits to the outpatient clinic for about 6 months, after which time their care may be continued by their regular doctors.

Practical points

A stem cell transplant is a complex treatment that can cause life-threatening side effects. If the doctors think your child can benefit from a transplant, the best place to have this done is at a nationally recognized cancer center where the staff has experience with the procedure and with managing the recovery period.

A stem cell transplant often requires a long hospital stay and can be very expensive (costing well over $100,000). Be sure to get a written approval from your insurer if the procedure is recommended for your child. Even if the transplant is covered by your health insurance, co-pays or other costs could easily amount to many thousands of dollars. Find out what your insurer will cover before the transplant so you will have an idea of what you might have to pay.

Possible side effects

The possible side effects from SCT are generally divided into early and long-term effects.

Early or short-term side effects

The early complications and side effects are basically the same as those caused by high-dose chemotherapy or radiation therapy and can be severe. They are caused by damage to the bone marrow and other quickly growing tissues of the body, and can include:

• Low blood cell counts (with fatigue and increased risk of infection and bleeding)
• Nausea and vomiting
• Loss of appetite
• Mouth sores
• Diarrhea
• Hair loss

One of the most common and serious short-term effects is an increased risk for serious infections. Antibiotics are often given to try to prevent this. Other side effects, like low red blood cell and platelet counts, might require blood product transfusions or other treatments.

Late or long-term side effects

Some complications and side effects can last for a long time or might not occur until months or years after the transplant. These can include:

• Radiation damage to the heart or lungs
• Problems with the thyroid or other hormone-making glands
• Problems with fertility
• Damage to bones or problems with bone growth
• Development of another cancer (including leukemia) years later

Be sure to talk to your child’s doctor before the transplant to learn about possible long-term effects your child might have. For more on the possible long-term effects of this and other treatments, see the section, Late and Long-term Effects of Neuroblastoma and Its Treatment.

For more information on stem cell transplants in general, see our document Stem Cell Transplant for Cancer.