A Phase II Single-arm Study of Total Body Irradiation With Linac Based VMAT and IGRT

Use of linac based Volumetric Arc Therapy (VMAT) to deliver Total Body Irradiation (TBI). The study intervention is a VMAT based delivery technique using a 6 MV photon beam from a Varian TrueBeam® (Palo Alto, CA) equipped with a Millennium multi-leaf collimation (MLC) system3. TBI will be delivered using a Varian TrueBeam linear accelerator with photon beam VMAT capability. VMAT is a radiation technique combining dynamic photon fluence modulation using multi-leaf collimation (MLC) with gantry rotation to deliver a highly conformal dose distribution with improved target coverage and sparing of organs at risk (OARs).