High-dose chemotherapy in childhood brain tumors

Early attempts to use high-dose chemotherapy technology in order to improve the effect of nitrosourea on high-grade gliomas resulted in minimal benefit as well as in severe toxicity. Since then, other drugs have been applied in conjunction with either autologous bone marrow or peripheral blood stem cells, including thiotepa, etoposide, melphalan, cyclophosphamide, and busulfan. The data suggest benefit in recurrent primitive neuroectodermal tumors (PNET), in newly diagnosed young children with PNET and possibly in young children with newly diagnosed ependymoma, as a strategy not only to improve tumor-free survival but also to avoid exposure of the young brain to irradiation. In other tumors such as recurrent ependymoma and newly diagnosed or recurrent brain stem glioma, high-dose chemotherapy remains ineffective. New protocols under evaluation include new agents, multiple cycles of high-dose chemotherapy and allogeneic transplantation as immunotherapeutic approach.