Target Volume Delineation and Radiation Planning Considerations for Total Body Irradiation

Radiotherapy (RT) is an important component of conditioning regimens for many hematological diseases, most frequently leukemias requiring an allogenic stem cell transplantation (SCT). Total body irradiation (TBI) remains an effective treatment in this setting. The myeloablative and non-myeloablative regimens vary across institutions in terms of dose, dose rate, fractionation, and technique. Modern techniques such as total marrow (TMI) and total marrow and lymphoid irradiation (TMLI) allow a more conformal delivery of RT dose, with a significant reduction of the toxicity profile. The objective of this chapter is to provide a comprehensive overview of the current practice of delivering RT in the conditioning regimens of SCT.