High risk/recurrent central nervous system (CNS) tumors have a poor prognosis so that tandem high dose chemotherapy (HDCT) with hematopoietic progenitor stem cell rescues has been chosen as potentially curative therapy. Many institutions have used carboplatin, thiotepa, etoposide (CTE) for conditioning regimen of 1st HDCT and cyclophosphamide, melphalan (CM) for conditioning regimen of 2nd HDCT. Our institution applied this regimen to the 38 pediatric patients with high risk brain tumor since 1996. Although the 3 year overall survival rate and event free survival rate were improved to 69% and 47.9%, respectively, the results showed relatively high treatment related mortality (TRM) rate of 21%. Toxicity of this tandem regimen was also reported as being high up to 32% in other researches as well so that this regimen is considered not feasible due to toxicity. In this study, the investigators plan to improve event free survival rate and reduce treatment related toxicities of pediatric patients with high risk/recurrent CNS tumors by administrating tandem high dose chemotherapy and autologous stem cell rescue with topotecan, thiotepa, carboplatin (TTC) for 1st HDCT and melphalan, etoposide, carboplatin (MEC) for 2nd HDCT.
The investigators plan to improve event free survival rate and reduce treatment related toxicities of pediatric patients with high risk/recurrent CNS tumors by administrating tandem high dose chemotherapy and autologous stem cell rescue.