Total Marrow and Lymphoid Irradiation and Chemotherapy Before DSCT in Treating Patients With High-Risk ALL or AML

This phase II trial studies the safety and efficacy of total marrow and lymphoid irradiation (TMLI) in combination with two chemotherapy drugs, etoposide and cyclophosphamide, as a preparative regimen before donor stem cell transplant in treating patients with high-risk acute lymphocytic leukemia (ALL) or acute myeloid leukemia (AML) who have failed previous therapy. Intensity-modulated radiation therapy (IMRT) uses imaging to provide a three-dimensional view of the area to be irradiated. Doctors can then shape and direct the radiation beams at the area from multiple directions while avoiding, as much as possible, nearby organs. TMLI is a method of using IMRT to direct radiation to the bone marrow. Radiation therapy is given before transplant to suppress the immune system, prevent rejection of the transplanted cells, and wipe out any remaining cancer cells. TMLI may allow a greater radiation dose to be delivered to the bone marrow as a preparative regimen before transplant while causing fewer side effects than standard radiation therapy.