Changes in recall type and patient treatment following implementation of screening digital breast tomosynthesis.

Purpose: To compare recall rate, types of abnormalities recalled, additional imaging required, biopsy positive predictive value (PPV), and cancer detection rate before and after implementation of screening digital breast tomosynthesis (DBT).
Materials and Methods: This retrospective analysis was approved by the institutional review board and complied with HIPAA. The requirement to obtain informed consent was waived. Results from all screening digital mammography (DM) examinations performed without tomosynthesis from March 1, 2011, through February 29, 2012, and DBT examinations performed from March 1, 2012, through February 28, 2013, were reviewed to identify all Breast Imaging Reporting and Data System (BI-RADS) category 0 examinations (needs additional imaging). Radiology and pathology reports were reviewed. The recall rate, biopsy PPV, and cancer detection rate were calculated. Statistical analysis was performed by using a two-proportions z test.
Results: The recall rate was 9.3% (1175 of 12 577 examinations; 95% confidence interval [CI]: 8.8%, 9.9%) for DM and 6.4% (827 of 12 921 examinations; 95% CI: 6.0%, 6.8%) for DBT, an overall reduction of 31% (P < .00001). The recall rate was lower with DM than with DBT for masses (8.9% vs 26.8%, respectively), distortions (0.6% vs 5.3%), and calcifications (13.4% vs 20.3%) (P < .0001 for all). The recall rate was lower with DBT than with DM for asymmetries (13.3% vs 32.2%, respectively) and focal asymmetries (18.2% vs 32.2%) (P < .0001 for both). Diagnostic evaluation with ultrasonography (US) increased with DBT at the time of additional imaging (2.6% for DM vs 28.3% for DBT, P < .0001). There was no significant difference between DM and DBT with regard to biopsy PPV (30.2% vs 23.8%, P = .21) or cancer detection rate per 1000 patients (5.4 vs 4.6, P = .44).
Conclusion: With DBT, the recall rate decreased and the biopsy PPV and cancer detection rate did not decrease. The distribution of recalled abnormalities changed, and more patients were evaluated with US only.
(© RSNA, 2014.)