<qa>  What is the risk of treatment-related mortality in the first 6 months?- Determine the feasibility of non-myeloablative allogeneic hematopoietic stem cell transplantation by demonstrating that the risk of treatment-related mortality during the first 6 months is an acceptable rate of less than 40 in patients with relapsed hematologic malignancies after prior high-dose chemotherapy and autologous stem cell transplantation. 