Monte Carlo simulations for X-ray breast dosimetry using homogeneous and heterogeneous phantoms

In this work a proposal for a new heterogeneous breast phantom to be adopted in Monte Carlo calculations for dosimetry in digital mammography is presented. The heterogeneous phantom is designed to avoid the current assumption of the homogeneous compound of the breast tissue adopted in the current international dosimetry protocols. With the aim to improve Monte Carlo accuracy, the phantom is chosen between two models developed using different approaches: A voxelized phantom and a ducts-and-lobules phantom using mathematical solids. For both models, dose estimates are calculated and compared with the reference homogeneous phantom, and the most reliable digital phantom is chosen and proposed for dosimetry purposes.