• Evaluate the morbidity and mortality of hematopoietic progenitor cell transplantation (HPCT) at Children's Memorial Hospital. [ Time Frame: To study end ] [ Designated as safety issue: Yes ]
  

• Evaluate the effectiveness of graft versus host disease prevention with a combination of anti-thymocyte globulin, continuous infusion cyclosporine, and short course methotrexate for transplants. [ Time Frame: To study end ] [ Designated as safety issue: Yes ]
  
• Determine the toxicity of a single conditioning regimen consisting of total body irradiation, etoposide, and Cyclophosphamide for patients with transplant eligible lymphoid malignant conditions or myeloid malignant conditions receiving cord blood units. [ Time Frame: To study end ] [ Designated as safety issue: Yes ]
  
• Determine the toxicity of a single conditioning regimen consisting of Busulfan and Cyclophosphamide for patients with transplant eligible myeloid malignant conditions who are not receiving cord blood units. [ Time Frame: To study end ] [ Designated as safety issue: Yes ]
  

Drug: Myeloablative Chemotherapy Regimen for Lymphoid Malignancies or Cord Blood Unit Recipients

Total Body Irradiation (TBI) 1200 cGy will be given on days -8,-7,-6 and -5 in eight sessions, delivering 150cGy in each session.

Etoposide 1000 mg/m2 as a 24 hour continuous infusion started on day -4.

Cyclophosphamide 60 mg/kg/day IV given over 1 hour daily on days -3, -2.

Drug: Myeloablative Chemotherapy Regimen for Non-Cord Blood Unit Recipients with Myeloid Malignancies

Busulfan administration:

• For children >/= 4 years of age, Busulfan 0.8 mg/kg/dose will be given every 6 hours over days -8,-7, -6, and -5 for a total of 16 doses.
• For children < 4 years of age, Busulfan 1 mg/kg/dose will be given every 6 hours over days -8, -7, -6, -5 for a total of 16 doses.
• Pharmacokinetic analysis will guide dose modifications targeted to receive an average AUC of 800-1200 microMols*min for the 16 doses.

Lorazepam (0.05 mg/kg) IV will be administered one half hour before the initial dose of Busulfan is given and every 6 hours through day -4.

Etoposide 1000 mg/m2 as a 24 hour continuous infusion started on day -4.

Cyclophosphamide 60 mg/kg/day IV given over 1 hour daily on days -3 and -2.

Other: Hematopoietic Progenitor Cell Transplantation (HPCT)
Hematopoietic progenitor cells (HPCs) will be infused on day 0. Source of cells may be bone marrow, peripheral blood cells, or cord blood units, from matched related or unrelated donors.
Radiation: CNS radiation treatment for ALL with prior CNS disease patients

Patients with prior CNS disease over the age of 1 year will be treated with 600 cGy of cranial irradiation in addition to 1200 cGy of TBI.

Patients diagnosed with ALL with CNS disease (at the time of diagnosis or relapse) < 1 year of age will receive CNS treatment as Intrathecal Methotrexate as follows:

• Infants ≤ 1 year of age at the time of Intrathecal Therapy will receive a dosing of 7.5 mg once a month for 6 months after transplant beginning at day +30 with an adequate white count
• Children 1-2 years of age at the time of Intrathecal Therapy will receive 8 mg once a month for 6 months after transplant beginning at day +30 with an adequate white count

Myeloablative hematopoietic progenitor cell transplantation (HPCT) remains the standard of care for patients requiring HPCT. The purpose of this study is to evaluate the morbidity and mortality of myeloablative HPCT at Children's Memorial Hospital. It will also look to determine the toxicity of a single conditioning regimen consisting of total body irradiation (TBI), etoposide (VP-16), and Cyclophosphamide for patients with transplant eligible lymphoid malignant conditions or with transplant eligible myeloid malignant conditions who are receiving cord blood units, or to determine the toxicity of a single conditioning regimen consisting of Busulfan and Cyclophosphamide for patients with transplant eligible myeloid malignant conditions who are not receiving cord blood units.