Radiolabeled Monoclonal Antibody Therapy, Fludarabine Phosphate, and Low-Dose Total-Body Irradiation Followed by Donor Stem Cell Transplant and Immunosuppression Therapy in Treating Older Patients With Advanced Acute Myeloid Leukemia or High-Risk Myelodysplastic Syndromes

Inclusion Criteria: Patients with advanced AML defined as beyond first remission, primary refractory disease, or evolved from myelodysplastic or myeloproliferative syndromes; or patients with MDS expressed as refractory anemia with excess blasts (RAEB), refractory anemia with excess blasts in transformation (RAEBT [Note: classification removed under current World Health Organization [WHO] classification system]), refractory cytopenia with multilineage dysplasia (RCMD), RCMD with ringed sideroblasts (RCMD-RS), or chronic myelomonocytic leukemia (CMML) Patients in relapse must have documented cluster of differentiation (CD)45 expression by their myelodysplastic or leukemic cells to be studied and treated with 131I-labeled BC8 antibody; patients in remission do not require phenotyping and may have leukemia previously documented to be CD45 negative Patients should have a circulating blast count of less than 10,000/mm^3 (control with hydroxyurea or similar agent is allowed) Patients must undergo a 24-hour urine collection with documented creatinine clearance > 50 ml/min Bilirubin < 2 times the upper limit of normal Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) < 2 times the upper limit of normal Karnofsky score >= 70 or Eastern Cooperative Oncology Group (ECOG) =< 2 Patients must have an expected survival of > 60 days and must be free of active infection Patients must have a human leukocyte antigen (HLA)-identical sibling donor or an HLA-matched unrelated donor who meets standard Seattle Cancer Care Alliance (SCCA) and/or National Marrow Donor Program (NMDP) criteria for peripheral blood stem cell (PBSC) donation; related donors should be matched by molecular methods at the intermediate resolution level at HLA-A, B, C, and DRB1 according to Fred Hutchinson Cancer Research Center (FHCRC) Standard Practice Guidelines and to the allele level at DQB1; unrelated donors should be identified using matching criteria that follows the FHCRC Standard Practice Guidelines limiting the study to eligible donors that are allele matched for HLA-A, B, C, DRB1, and DQB1 (grade 1), and accepting up to one allele mismatch as per standard practice grade 2.1 for HLA-A, B, or C; PBSC is the only permitted hematopoietic stem cell (HSC) source DONOR: Donors must meet HLA matching criteria as outlined above as well as standard Seattle Cancer Care Alliance (SCCA) and/or NMDP criteria for PBSC donation Exclusion Criteria: Circulating antibody against mouse immunoglobulin (human anti-mouse antibody [HAMA]) Prior radiation to maximally tolerated levels to any normal organ Patients may not have symptomatic coronary artery disease and may not be on cardiac medications for anti-arrhythmic or inotropic effects Inability to understand or give an informed consent Patients who are seropositive for human immunodeficiency virus (HIV) Perceived inability to tolerate diagnostic or therapeutic procedures, particularly treatment in radiation isolation Patients who have previously undergone marrow or PBSC transplantation