Objective: This study evaluated digital breast tomosynthesis (DBT) as an alternative to conventional diagnostic mammography in the workup of noncalcified findings recalled from screening mammography in a simulated clinical setting that incorporated comparison mammograms and breast ultrasound results.
Subjects and methods: One hundred forty-six women, with 158 abnormalities, underwent diagnostic mammography and two-view DBT. Three radiologists viewed the abnormal screening mammograms, comparison mammograms, and DBT images and recorded a DBT BI-RADS category and confidence score for each finding. Readers did not view the diagnostic mammograms. A final DBT BI-RADS category, incorporating ultrasound results in some cases, was determined and compared with the diagnostic mammography BI-RADS category using kappa statistics. Sensitivity and specificity were calculated for DBT and diagnostic mammography.
Results: Agreement between DBT and diagnostic mammography BI-RADS categories was excellent for readers 1 and 2 (κ = 0.91 and κ = 0.84) and good for reader 3 (κ = 0.68). For readers 1, 2, and 3, sensitivity and specificity of DBT for breast abnormalities were 100%, 100%, and 88% and 94%, 93%, and 89%, respectively. The clinical workup averaged three diagnostic views per abnormality and ultrasound was requested in 49% of the cases. DBT was adequate mammographic evaluation for 93-99% of the findings and ultrasound was requested in 33-55% of the cases.
Conclusion: The results of this study suggest that DBT can replace conventional diagnostic mammography views for the evaluation of noncalcified findings recalled from screening mammography and achieve similar sensitivity and specificity. Two-view DBT was considered adequate mammographic evaluation for more than 90% of the findings. There was minimal change in the use of ultrasound with DBT compared with diagnostic mammography.