Estimating mean glandular dose using proprietary mammography phantoms

Screening mammography programs prescribe limits on the radiation dose to the glandular tissue of a compressed breast — the Mean Glandular Dose (MGD) — which may vary between 2 and 3 mGy for a 50% adipose and 50% glandular tissue compressed breast of 4.2 to 5.0 cm thickness. Commercially available breast phantoms offer a choice of equivalent tissue thicknesses and composition ranging typically from 30% adipose and 70% glandular tissue to 50% adipose and 50% glandular tissue. A number of these phantom were compared under clinical conditions and the MGD calculated for each using the factors developed by Wu et al. [Wu, X., Barnes, G.T. and Tucker, D.M. (1991) Spectral dependence of glandular tissue dose in screen film mammography, Radiology 179, 143–148].