Neuroblastoma is one of the most common types of solid tumors in childhood. While many children with neuroblastoma may be cured by surgically removing the tumor followed by chemotherapy treatments, those with extensive disease or features that indicate a very high likelihood of recurrence — often referred to as high risk — may not respond as well to this standard therapy.
The UCSF Benioff Children's Hospital Bone Marrow Transplant Program offers autologous bone marrow stem cell transplantation to treat children with high-risk neuroblastoma. In this type of transplant, high dose chemotherapy used during a conditioning period is given to kill the tumor. Bone marrow function is then restored by infusing the patient's own previously stored bone marrow cells. One advantage to this approach is that it eliminated the risk of graft-versus-host disease (GvHD).
Because the majority of these children have neuroblastoma cells in their bone marrow, special techniques are used to remove these cancer cells from previously collected bone marrow cells prior to transplant. The purified bone marrow stem cells are stored in liquid nitrogen until the day of transplant. More recently, this purging technique has been adapted to treat circulating bone marrow stem cells in the blood that have been collected by a procedure called leukapheresis for a peripheral blood stem cell transplant (PBSC). There are some data to suggest that purging is not necessary with PBSC collections. Currently, the UCSF Benioff Children's Hospital BMT Program is participating in a national study conducted by the Children's Oncology Group that is evaluating the efficacy of PBSC purging in patients with newly diagnosed high risk neuroblastoma.
In addition, novel research protocols are available at UCSF Benioff Children's Hospital for children who have either failed to respond to initial chemotherapy treatment or who have relapsed after an initial response. These children are not candidates for the standard autologous transplant but may be eligible for combined targeted radiation therapy followed by an autologous transplant.
High-risk metastatic neuroblastoma that does not initially respond to chemotherapy or progresses after initial chemotherapy treatment is usually unresponsive to further treatment, even with therapy that includes intensive chemotherapy and bone marrow stem cell transplantation. New approaches are needed for such resistant tumors. MIBG is a chemical that mimics certain natural compounds in the body that are concentrated in selective tissues including neuroblastoma cells. 131I is an isotope of iodine that emits powerful radioactive energy, sufficient to kill tumor cells. 131I can be chemically attached to MIBG to form a compound that holds promise for cell-specific treatment of neuroblastoma. Under the leadership of Dr. Katherine Matthay, treatment with 131I-MIBG alone was evaluated at UCSF in children with progressive or relapsed neuroblastoma. In 20 percent to 40 percent of these children, the tumors decreased in size. The major downside that was seen was a suppression of normal marrow function, which could be corrected by autologous stem cell transplant. Significant organ damage outside the bone marrow has yet to be seen.
Based on these observations we believe that doses of 131I-MIBG can be increased with the support of autologous bone marrow rescue or peripheral blood stem cell rescue. Furthermore, we believe that by combining higher doses of 131I -MIBG with high dose chemotherapy followed by an autologous bone marrow stem cell transplant, children with otherwise untreatable neuroblastoma will have a chance at long-term survival with less risk of organ damage than has previously been seen.
Patients with neuroblastoma who have had a poor response to chemotherapy or whose disease has progressed while on chemotherapy or after previous therapies are eligible for this study.
You can find out more about cancer trials here.
MIBG is a clear liquid that is administered through an IV in the arm or hand. Though the actual IV infusion only lasts about 2 hours, parents should expect their child to be in the hospital from 6 to 8 days. The treatment does not cause significant side effects for most, but the patient is considered radioactive for 4 to 5 days and must be partially isolated in a special room outfitted with lead shields. Parents are allowed daily contact with their child for a certain amount of time each day, depending on the amount of radiation detected at the time.
The most difficult part of the process for many patients is the boredom associated with lying in bed for so many days. Video games and other electronic devices are allowed, and the nurses and other staff will work with you to make sure your child is as comfortable as possible. More information about MIBG is available here.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Blood & Marrow Transplant Program
505 Parnassus Ave., Sixth Floor, Room M-659
San Francisco, CA 94143
Phone: (415) 476-2188
Fax: (415) 502-4867
Blood & Marrow Transplant Clinic
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San Francisco, CA 94143-0134
Phone: (415) 353-2584
Fax: (415) 353-2600