Simulation of volumetric breast densities for virtual clinical trials

Virtual clinical trials (VCTs) in medical imaging can be used as a supplement to clinical trials, as they are less costly and less time-consuming and do not depend on study participants. This study aims at modeling the variety in volumetric breast density (VBD) in a virtual population of women attending mammography and breast tomosynthesis screening. Probability distributions (PDs) were fitted to available clinical data on VBD from Malmo, for women in different age groups. The PDs were then used for sampling VBD values for virtual populations. Each age group had two virtual populations, one containing N=30 samples and the other N>1500 samples. The sampled VBD and the clinical VBD were compared both for the large and small populations. Results showed that the VBD probability distributions vary between different age groups in the clinical population and that the mean VBD decreases with aging. It also showed that the simulated VBD (both the large and small populations) does not significantly differ from the clinical data (p>0.07) and that the mean VBD also decreases for the simulated populations. The larger population (N>1500) had a smaller percent error than the smaller virtual population (N=30) when compared with the clinical mean VBD values. The study suggests that the method could be applied when simulating VBD for virtual patients in VCTs.