High-dose Chemotherapy and Stem Cell Transplant for Neuroblastoma

High-dose chemotherapy with a stem cell transplant is often used in children with high-risk neuroblastoma.

General information

Higher doses of chemo, which are good for treating difficult cancers, can damage the young blood-forming stem cells permanently. When high doses of chemo are needed as part of treatment, blood stem cells can be saved (harvested) before high-dose chemo is given. These blood stem cells are given back to the child after high-dose chemo is done to replace the blood and allow the marrow to regrow. This is called a stem cell transplant (SCT).

Before the SCT, a child is usually given about 5 months of intense chemotherapy and sometimes surgery to remove the tumor as well. Some children might get 2 SCTs a few months apart, called tandem stem cell transplants.

SCT 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 cancer center where the staff has experience with the procedure and managing the recovery period.

Collecting stem cells before the transplant

For most children with neuroblastoma, their own stem cells are collected and used for the transplant. This is called an autologous SCT.

To help prepare for stem cell collection, doctors give a medicine called G-CSF (filgrastim), which helps the bone marrow make more stem cells and helps those cells move into the bloodstream for collection.

G-CSF is usually started at the end of a regular cycle of chemo and is given daily. Once part of the white blood cell count (known as the absolute neutrophil count, or ANC) reaches a certain level, the dose of G-CSF is increased until there are enough stem cells to collect.

The child will have a special kind of central venous catheter put in place so the stem cells can be collected during a process called apheresis. The collection process is like 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 child’s body. Apheresis can take a few hours, and your child will need to lie flat and hold still during the procedure. This process may be repeated over a few days. The collected stem cells are frozen and saved until they are needed for the transplant.

The high-dose chemo and transplant procedure

Typically, the child will be admitted to the SCT unit of the hospital on the day before the high-dose chemo begins. They 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 (typically several weeks or more).

The child gets high-dose chemo first. This destroys the cancer cells in the body, as well as the normal cells in the bone marrow. After the chemo, 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. Soon after, they will start making new red blood cells and platelets. Until new blood cells are made, the child is at high risk of infection and bleeding. To help lower the risk of infection, the child stays in a special hospital room, and visitors are limited and must wear protective clothing. Blood and platelet transfusions will be given as needed while the bone marrow recovers. Children may also need antibiotics to treat infections while the body heals.

The child usually stays in the hospital room until the infection-fighting white blood cells rise to safe levels. Even after discharge from the hospital, children often need care in an outpatient clinic almost every day for several weeks. Your transplant team will decide when it is safe for you to return to your regular doctors.

Possible side effects

A stem cell transplant can have both short-term and long-term side effects.