Total Marrow and Lymphoid Irradiation

This phase II trial studies how well total marrow and lymphoid irradiation works as a conditioning regimen before hematopoietic cell transplantation in patients with myelodysplastic syndrome or acute leukemia. Total body irradiation can lower the relapse rate but has some fatal side effects such as irreversible damage to normal internal organs and graft-versus-host disease (a complication after transplantation in which donor's immune cells recognize the host as foreign and attack the recipient's tissues). Total body irradiation is a form of radiotherapy that involves irradiating the patient's entire body in an attempt to suppress the immune system, prevent rejection of the transplanted bone marrow and/or stem cells and to wipe out any remaining cancer cells. Intensity-modulated radiation therapy (IMRT) is a more recently developed method of delivering radiation. Total marrow and lymphoid irradiation is a method of using IMRT to direct radiation to the bone marrow. Total marrow and lymphoid irradiation may allow a greater dose of radiation to be delivered to the bone marrow as a preparative regimen before hematopoietic cell transplant while causing less side effects to normal organs than standard total body irradiation.