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

This trial studies how well radiation therapy techniques, volumetric modulated arc therapy (VMAT) and tomotherapy, work to reduce doses to the lung compared to standard total body irradiation methods to prevent pulmonary toxicities. Standard total body irradiation is limited in its ability to spare normal organs, with only the lung being partially spared by lung blocks and risks the development of pulmonary toxicities. Reducing the doses to the lung using VMAT or tomotherapy may improve survival and decrease long term lung side effects in patients undergoing stem cell transplant.