Impact of ICRP-89 Based Models on Dose Estimates for Radiopharmaceuticals and CT Exams

New mathematical phantoms based on medical image data are allowing evaluation of internal and external dose calculations using better anatomic realism and inclusion of organs that were not previously defined. In this work, we show preliminary data for new radiation dose estimates for radiopharmaceuticals and CT examinations, using Monte Carlo radiation simulation routines developed in the Geant4 toolkit. Radiopharmaceutical dose estimates show some differences in individual organ dose estimates, but overall very similar effective dose estimates for most radiopharmaceuticals in common use. CT dose estimates now allow for estimation of dose to individual organs as well as accurate effective dose estimates, instead of traditionally available estimates of standard dose to one of two standard sized acrylic phantoms, and, via the use of deformable phantoms, lead to the ability to calculate organ doses and effective doses to more patient-individualized models.