Calculation and prescription of dose for total body irradiation

The use of large total body fields creates a unique set of problems that stress the accuracy of techniques routinely used for dose calculation. This paper discusses an approach suggested by the Children's Cancer Study Group (CCSG) for both prescribing the total body irradiation (TBI) dose and calculating the beam-on time or meter set needed to deliver it. It is aimed at guaranteeing the accuracy of the calculations, while at the same time ensuring a high degree of compliance for the various CCSG protocols using TBI. Data supporting the various CCSG recommendations are presented.