Comparison of various anthropomorphic phantom types for in vivo measurements by means of Monte Carlo simulations.

Three widely used anthropomorphic phantoms are analysed with regard to their suitability for the efficiency calibration of whole-body counters (WBCs): a Bottle Manikin Absorber (BOMAB) phantom consisting of water-filled plastic containers, a St Petersburg block phantom (Research Institute of Sea Transport Hygiene, St Petersburg) made of polyethylene bricks and a mathematical Medical Internal Radiation Dose (MIRD) phantom, each of them representing a person weighing 70 kg. The analysis was performed by means of Monte Carlo simulations with the Monte Carlo N-Particle transport code using detailed mathematical models of the phantoms and the WBC at Forschungszentrum Jülich (FZJ). The simulated peak efficiencies for the BOMAB phantom and the MIRD phantom agree very well, but the results for the St Petersburg phantom are considerably higher. Therefore, WBCs similar to that at FZJ will probably underestimate the activity of incorporated radionuclides if they are calibrated by means of a St Petersburg phantom. Finally, the results from this work are compared with the conclusions from other studies dealing with block and BOMAB phantoms.