Monte Carlo evaluated parameters for internal dosimetry.

The radiation doses received by individuals from radionuclides which enter the human body cannot be measured directly but must be inferred. In these calculations, several measurable quantities (such as the internal whole body burden or urine daily excretion) and quantities derived from models are employed. The Radiation Protection Quantities for internal dosimetry are, in principle, the same as for external dosimetry with the addition of quantities taking into account that the doses in the body are protracted. Other parameters are also necessary for the dose assessment, such as the SAFs (Specific Absorbed Fractions). All these quantities are calculated using Monte Carlo codes and complex anthropomorphic phantoms. Monte Carlo codes are also widely employed as useful tools during the calibration procedure for in vivo measurements. This paper summarises the role played by Monte Carlo modelling in these fields.