Can grating interferometry-based mammography discriminate benign from malignant microcalcifications in fresh biopsy samples?

Purpose
In addition to absorption imaging, grating interferometry-based mammography (GIM) is capable of detecting differential-phase and scattering signals. In particular, the scattering signal can enable a quantifiable characterization of breast lesions. The purpose of this study was to determine if suspicious microcalcifications associated with benign or malignant lesions can be discriminated based on their absorption and scattering properties.
Materials and Methods
In this prospective, ethically approved study, 62 patients (mean age 60 y, range 39–89) with suspicious microcalcifications, who underwent stereotactic biopsies, were included. Biopsies were measured with an experimental GIM device and the ratios of the scattering and absorption signal (R-value) for microcalcifications were calculated. The mean R-values for benign and malignant lesions associated with microcalcifications were compared with the final histopathological diagnosis using a t-test.
Results
Twenty of the 62 participants had microcalcifications associated with malignancy. Comparing the two largest histopathological sub-groups of fibrosis (n = 23) vs. ductal carcinoma in situ (n = 15) resulted in an average R-value of 4.08 for benign and 2.80 for malignant lesions; p = 0.07. All microcalcifications associated with malignancy had an R-value below 4.71. Excluding microcalcifications with an R-value above this threshold would result in an 11 % reduction of false positives.
Conclusion
The novel GIM modality has the potential to non-invasively characterize microcalcifications and might aid in the discrimination of benign from malignant lesions in fresh biopsy samples.