TBI Using IMRT (VMAT or Tomotherapy) for the Prevention of Pul Toxicities in Patients Undergoing Donor SCT

Inclusion Criteria: * Karnofsky performance status (KPS) \>= 70 * Acute leukemia or myelodysplastic patients evaluated within 30 days of start of conditioning regimen who would be candidates for TBI-cyclophosphamide (Cy) or TBI-etoposide (VP16) per City of Hope (COH) standard operating procedure (SOP) for allogeneic hematopoietic stem cell transplant * Patients must be suitable for TBI conditioning regimens as part of transplant per the referring hematologist * Patients must have adequate organ function for hematopoietic cell transplantation (HCT) as determined by the hematologist * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for six months following duration of study participation * All subjects must have the ability to understand the treatment and the willingness to sign a written informed consent * The effects of total body radiation on the developing fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for six months following duration of study participation. Should a woman become pregnant or suspect that she is pregnant while participating on the trial, she should inform her treating physician immediately * Although not mandated by the protocol, the results of the imaging scans and labs (complete blood count \[CBC\], comprehensive metabolic panel \[CMP\]) that are performed as part of the standard work up should be available and should have been done within 2 months prior to study entry * Prior therapy (chemotherapy, immunotherapy, radiotherapy) must be completed at least 2 weeks prior to TBI * All patients with prior radiotherapy need to be reviewed with the principal investigator (PI) to determine eligibility * Prior therapy with chemotherapeutic agents is allowed * DONOR: Donor evaluation and eligibility will be assessed per current COH standard operating procedure Exclusion Criteria: * Patients should not have any uncontrolled illness including ongoing or active infection * Prior history of radiation therapy must be presented to study PI for eligibility determination * Pregnant women are excluded from this study because total body irradiation is an agent with the potential for teratogenic or abortifacient effects * Subjects, who in the opinion of the investigator, may not be able to comply with the safety monitoring requirements of the study