Retrospective comparison of Digital mammography versus Synthetic mammography for the detection of calcifications and breast malignancy.

Purpose: Calcifications detected on mammography are associated with benign and malignant pathologies. Full field digital mammography (FFDM) has high contrast resolution allowing clear depiction of calcifications. Digital breast tomosynthesis (DBT) utilizes the synthetic composite view (C-View) in conjunction with tomosynthesis to evaluate calcifications. The addition of DBT to FFDM increases radiation dose, but phantom doses still fall within the Mammography Quality Standards Act regulation of 3.0 mGy per view. In an attempt to decrease radiation dose, many institutions now forgo FFDM. Research supports analysis of calcifications on C-view/DBT. Appearance of mammographic microcalcifications may vary when comparing C-View images with FFDM. Experience at our institution has shown that faint/small round and amorphous calcifications may be harder to perceive on C-View images. Our study aims to evaluate the performance of C-view/DBT compared to FFDM in the detection of suspicious microcalcifications leading to stereotactic biopsy at a tertiary care center.

Methods/Materials: We retrospectively evaluated stereotactic biopsies performed for suspicious calcifications at our institution from 2013 to 2020. We evaluated the pathology results during 2 years of FFDM only (2013-2015), FFDM + C-view/DBT only (2015-2017), and C-view/DBT only (2018-2020). Pathology results were recorded as benign, malignant (invasive cancers and ductal carcinoma in situ) or high risk.

Results: From 2013-2015, 260 total biopsies were performed for microcalcifications identified with FFDM only. Of these, 98 were positive: 31 high risk, 46 DCIS, 4 LCIS, and 17 IDC. From 2015-2017, 258 total biopsies were completed for microcalcifications identified with FFDM + C-view/DBT. Of these, 85 were positive: 31 high risk, 43 DCIS, 5 LCIS, and 6 IDC. From 2018-2020, 190 total biopsies were performed for microcalcifications found with C-view/DBT alone. Of these, 59 were positive: 17 high risk, 28 DCIS, 0 LCIS, and 3 IDC.

Conclusions: Our data demonstrated that the C-view/DBT only detected less microcalcifications compared to prior years. In addition, it detected less malignancies and atypias overall compared to FFDM only or FFDM + C-view/DBT combination mode.