Incorporating Intensity Modulated Total Body Irradiation (IMRT-TBI) Into Future Cooperative Group Clinical Trials: An NRG Hematologic Malignancies Working Group-Led Report From the National Clinical Trials Network

Kovalchuk N, Simiele EA, LaRiviere M, Hiniker SM, Soike M, Han C, Wong J, Dandapani S, Kumar K, Parsons D, Teruel JR, Gerber NK, Guo B, Cherian S, Lim TY, Latifi K, Figura NB, Shrestha DK, Grecula J, Sim AJ, Parikh RR, Lo AC, Smith K, Plastaras JP, Xiao Y, Hoppe BS, Milgrom SA. Incorporating Intensity Modulated Total Body Irradiation (IMRT-TBI) Into Future Cooperative Group Clinical Trials: An NRG Hematologic Malignancies Working Group-Led Report From the National Clinical Trials Network. Int J Radiat Oncol Biol Phys. 2026 Feb 17:S0360-3016(26)00388-3. doi: 10.1016/j.ijrobp.2026.02.201. Epub ahead of print. PMID: 41713515; PMCID: PMC13166410.

Intensity-modulated radiation therapy (IMRT) has been used with increasing frequency for total body irradiation (TBI), given its ability to deliver myeloablative doses to the whole body while reducing dose to radiosensitive organs. Future National Clinical Trials Network (NCTN) trials should allow TBI to be delivered with IMRT, so institutions can use their preferred TBI approach and patient outcomes can be rigorously assessed. However, no standardized IMRT-TBI approach exists to apply across protocols. To address this gap, the NRG Hematologic Working Group led an initiative with IMRT-TBI experts and hematologic malignancy radiation oncology leaders from the NCTN groups. A 47-question survey was sent to participating institutions to assess current IMRT-TBI planning and delivery practices. Responses revealed variability across institutions, highlighting the need for standardization to ensure consistency in clinical trials. In this work, we describe recommended best practices for implementation of IMRT-TBI into multi-institutional trials.