Stem Cell Transplantation Stephan AGrupp 1161 Introduction

The role of autologous stem cell transplantation (ASCT) as consolidation therapy for malignancies has been debated, both in the pediatric as well as the adult setting. General design criteria include: (a) a chemo-responsive tumor type, typically with a good initial response to induction therapy,but a poor long-term (i.e., 3- or 5-year) outcome; (b) a conditioning (pre-transplant chemotherapy) regimen that may be dose-escalated safely past marrow tolerance; (c) conditioning agents not utilized in the induction chemotherapy; and (d) optimal supportive care, especially as regards stem cell source and processing techniques. The use of this treatment option, especially in the era of peripheral blood stem cell (PBSC) collection, has special challenges when applied to young patients with neuroblastoma where the median age at diagnosis is 3. Finally, although the vast majority of transplant procedures for patients with NB now utilize autologous PBSC as the stem cell source, allogeneic transplant has been advocated by some investigators, so we briefly explore this issue as well.

The primary source of hematopoietic stem and progenitor cells for use in autologous and allogeneic transplantation has been, until recently, bone marrow. Over the past decade, there has been an increasing use of peripheral blood containing mobilized stem and progenitor cells for transplantation (Table 11.6.1; Kessinger et al. 1986). This product is variously referred to as peripheral blood stem cells, peripheral blood progenitor cells, or given the shorthand designation "stem cells." Although each cell source used for hematopoietic transplantation contains stem cells, when the term "stem cells" is used without a qualifier, it is usually referring to PBSC.

Table 11.6.1 Cellular characteristics of various stem-cell sources. PBSC peripheral blood stem cell

Stem-cell source

Bone marrow

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