Comparing Diagnostic Performance of Digital Breast Tomosynthesis and Full-Field Digital Mammography

Objective: Compare diagnostic performance of screening full-field digital mammography (FFDM), a hybrid FFDM and digital breast tomosynthesis (DBT) environment, and DBT only. Materials and Methods: This institutional review board–approved, retrospective study consisted of all patients undergoing screening mammography at an urban academic medical center and outpatient imaging facility between January 1, 2011, and December 31, 2017. We used the electronic health record data warehouse to extract report data and patient demographics. A validated natural language processing algorithm extracted BI-RADS score from each report. An institutional cancer registry identified cancer diagnoses. Primary outcomes of recall rate, cancer detection rate (CDR), and positive predictive value 1 (PPV1) were calculated for three periods: FFDM-only environment, hybrid environment, and DBT-only environment. A χ² test was used to compare recall rate, CDR, and PPV1. Results: A total of 179,028 screening mammograms comprised the study cohort: 41,818 (23.3%) during the FFDM-only period, 83,125 (46.4%) during the hybrid period, and 54,084 (30.2%) during the DBT-only period. Recall rates were 10.4% (4,279 of 41,280) for the FFDM-only period, 10.6% (8,761 of 82,917) for the hybrid period, and 10.8% (5,850 of 54,020) for the DBT-only period (P = .96). CDR (cancers per 1,000 examinations) was 2.6 per 1,000, 4.9 per 1,000, and 6.0 per 1,000 for FFDM only, hybrid, and DBT only, respectively (P < .01). PPV1s (number of cancers per number of recalls) were 2.5% for the FFDM-only period, 4.6% for the hybrid period, and 5.6% for the DBT-only period (P < .01). Conclusion: Recall rates were not significantly different within the three periods in the breast imaging practice. However, PPV1 and CDR were significantly higher with DBT only.