Quantities for assessing high photon doses to the body: a calculational approach

Tissue reactions are the most clinically significant consequences of high-dose exposures to ionising radiation. However, currently there is no universally recognized dose quantity that can be used to assess and report generalised risks to individuals following whole body exposures in the high-dose range. In this work, a number of potential dose quantities are presented and discussed, with mathematical modelling techniques employed to compare them and explore when their differences are most or least manifest. The results are interpreted to propose the average (D _GRB) of the absorbed doses to the stomach, small intestine, red bone marrow, and brain as the optimum quantity for informing assessments of risk. A second, maximally conservative dose quantity (D _Max) is also suggested, which places limits on any under-estimates resulting from the adoption of D _GRB. The primary aim of this work is to spark debate, with further work required to refine the final choice of quantity or quantities most appropriate for the full range of different potential exposure scenarios.