The study was terminated as recommended by the DSMB due to inability to meet enrollment goals within the time frame allotted (target of 25 patients over 5 years).

This is a study of amifostine to determine how effective it is in the reduction of infection in a high dose chemotherapy regimen with autologous stem cell rescue in children with high risk, relapsed or refractory pediatric solid tumors.

Autologous stem cell transplant (ASCT) permits chemotherapy dose-escalation to exploit the steep dose-response of solid tumors to alkylating agents. Although ASCT regimens have activity in some high risk pediatric solid tumors, non-hematological regimen-related morbidity and mortality are major barriers to additional dose escalation. We hypothesized that the chemoprotectant amifostine (Ethyol®) would reduce the toxicity of ASCT without compromising anti-tumor efficacy. This is a study of amifostine at 1125 mg/m2 to determine the efficacy of it's chemoprotection in the reduction of bacteremia in a high dose busulfan, melphalan and thiotepa chemotherapy regimen with autologous stem cell rescue in children with high risk, relapsed or refractory pediatric solid tumors.

Inclusion Criteria:

• High risk Ewing's Sarcoma Family Tumors (ESFT) including Ewing's Sarcoma, Askin's tumor, peripheral PNET
• High risk desmoplastic small round cell tumors (DSRCT)
• Relapsed Wilm's tumor, diffuse anaplastic Wilm's tumor
• High risk brain tumors including PNET/Medulloblastomas/germinomas
• Relapsed germ cell tumors
• Metastatic or relapsed rhabdoid tumors
• Other relapsed/refractory pediatric embryonal tumors
• Less than 30 years of age
• Performance >= 50%
• Cancer Diagnosis verification and staging
• Disease Response and Recovery
• Adequate Organ Function (Renal, Liver, Cardiac)

Exclusion Criteria:

• Uncontrolled Infection
• Pregnancy or Breastfeeding (For Females)
• Disease Progression
• Uncontrolled Intercurrent Illness
• HIV Positive
• Receiving other Investigational Agents
• Amifostine Allergy