The purpose of this study is to evaluate the OS, RFS, and TRM after HCT with low-dose total body irradiation, fludarabine, and busulfan conditioning.

Conventional allogeneic hematopoietic cell transplantation (HCT) for patients with hematological malignancies involves conditioning with high doses of systemic chemo/radiation therapy such as cyclophosphamide (CY) plus 1200 or 1000 cGy total body irradiation (TBI; CY/TBI) or busulfan (Bu) / CY (BuCy). Unfortunately, such regimens have been associated with significant toxicities, limiting their use to otherwise healthy, relatively young patients.

Recently, Fludarabine plus 4 day dose of busulfan (FluBu4) containing myeloablative regimen has been introduced successfully without increasing transplant-related mortality (TRM). To improve transplant outcomes without increasing the risk of recurrence, Russell et al introduced 400cGy of TBI with antithymocyte (ATG, 4.5mg/Kg) into FluBu4 regimen with successful outcomes.

Inclusion Criteria:

• At least 15 years old and not more than 65 years old.
• ECOG performance status 0-2.
• Patients with AML or MDS with intermediate/unfavorable cytogenetics.
• Patients with ALL and CML ineligible for Cy/TBI conditioning.
• Patients with NHL or HD eligible to myeloablative HCT.
• Patients receiving unrelated BMT for AML, MDS, ALL, CML, NHL or HD.
• Consent form signed and dated prior to study specific procedures.
• Subject able to comply with the scheduled follow-up and with the management of toxicities.

Exclusion Criteria:

-