Dosimetric Modeling of Mammography Using the Monte Carlo Code PENELOPE and Its Validation

摘要

The Monte Carlo code PENELOPE (version 2014) and its software package PenEasy have been employed to closely simulate a commercial mammography system: Selenia Dimensions system (Hologic, Bedford, Mass) for dosimetric study. Normalized glandular dose (D_gN) was derived for specific filter combinations including tungsten/aluminum (W/Al), tungsten/rhodium (W/Rh) and tungsten/silver (W/Ag) for a range of clinically used voltages (kV). Breast models with thickness 2 cm, 4.5 cm and 8 cm and respective glandularity 100 %, 50 % and 0.1 % were included in the simulations. Derived D_gN values were in good agreement with well-accepted published values, with mean differences of 1.30 %, 2.17 % and 0.17 % for the W/Al, W/Rh and W/Ag anode/filter combinations, respectively. In the next phase of the study, this validated model will be modified to perform patient-specific dosimetry with an improved breast model and more realistic simulation of commercial mammography systems.