Pre-Admission

Prior to entering the Transplant Unit, the patient will require one or more of the following:

• insertion of a special intravenous catheter (required for all transplant recipients);
• collection of peripheral blood bone marrow stem cells (PBSC collection, required for cancers such as lymphomas, neuroblastoma, sarcomas, PNET, and Wilm’s tumor);
• bone marrow stem cell harvest (required when a PBSC collection is not possible or is inadequate);
• busulfan pharmacokinetic study (required if your child will be receiving busulfan as part of the conditioning regimen).

Catheter placement

The central venous catheters are special types of IV's that remain in place throughout the entire transplant process and help avoid the pain and discomfort of multiple IV's and blood draws. Through these catheters, chemotherapy, medications, blood products and nutritional support will be administered. These special IV's are also used for blood drawing.

The Hickman or Broviac catheter (two of the more common types) is inserted in the operating room. Some children already may have had this operation in order to facilitate treatment of their disease. While under general anesthesia, the catheters are inserted into major blood vessels in the neck and exit the skin on the front of the chest or abdomen. A total of 2 catheters (1 double lumen or 2 single lumen) are most often necessary. The procedure usually does not require hospitalization.

Parents and children (depending on age) will be taught how to care for the catheters and change the dressings. The catheters typically remain in place for 3-12 months post-transplant.

Bone marrow harvest

Bone marrow may be obtained from the patient for transplantation for solid tumors or as a back up to a T cell depleted marrow from a parent. While the patient is asleep under general anesthesia, multiple marrow aspirations are obtained from the pelvic bones along the lower back. The collected marrow is taken to the Pediatric BMT Laboratory for further processing and storage. The back-up marrow will be used in the event that the parental stem cell transplant fails to engraft. If possible, the back-up marrow, catheter insertion, and any other necessary surgical procedures will be done under the same anesthetic.

Peripheral blood stem cell (PBSC) collection

When this procedure is done for an autologous transplant, it occurs following a course of chemotherapy when the marrow and cell counts are recovering. A drug called G-CSF (granulocyte colony stimulating factor) is administered daily to the patient by injections under the skin beginning three days after the chemotherapy has been given. The patient will need daily blood and platelet counts to determine the timing of the special procedure called leukapheresis. During leukapheresis, blood is removed from the patient and passed through a special machine which collects those white cells which contain the bone marrow stem cells that are present in the blood. The remaining blood is returned to the patient. The procedure is done as an outpatient and takes 4-5 hours. Depending on the number of stem cells collected, more than one leukapheresis may need to be done. Also, the leukapheresis may require the placement of a special catheter on the day of or prior to the procedure. The placement of the catheter can sometimes be done in the Radiology Department under local or general anesthesia.

Busulfan pharmacokinetic study

If the patient is going to receive busulfan as part of the conditioning regimen, a pharmacokinetic study will be done prior to admission for transplant. Busulfan is a chemotherapy drug that in the past could only be taken by mouth as a pill or, in young children, administered through a soft feeding tube that is place through the nose into the stomach. More recently, an intravenous preparation of busulfan has become available, which will eventually replace the pill form. It is known that the amount of busulfan that gets absorbed into the blood stream and excreted by the body (that is, the effective drug) varies from one child to the next. By measuring the pharmacokinetics of a small test dose of busulfan, the precise dose of the drug can be determined for each child in order to optimize the amount that gets into the blood stream while minimizing toxicity. The pharmacokinetic study is done as an outpatient in the Pediatric Clinical Research Center (PCRC) several days prior to admission for transplant. The transplant attending will discuss the pharmacokinetic study in more detail at the informed consent conference.