Autologous stem cells are obtained prior to the administration of thiotepa. Patients who do not have peripheral blood stem cells available may undergo a bone marrow harvest instead. Thiotepa is administered as a 3 hour infusion daily for 3 consecutive days. Stem cells are reinfused approximately 72 hours following the completion of thiotepa. Filgrastim is administered the day following reinfusion of stem cells and continues until there is sufficient hematopoietic recovery.