Diagnostic Management Pathways for Workup of Abnormal Screening With Digital Mammography Versus Digital Breast Tomosynthesis.

Purpose: Our objective was to assess the transition from digital mammography (DM) to digital breast tomosynthesis (DBT) screening, the authors compared diagnostic workup type and frequency, workup pathways, and time to resolution of abnormal screening between DBT and DM.

Methods: This cohort study included screening examinations with an abnormal results from 2011 to 2020 at 107 facilities across six Breast Cancer Surveillance Consortium registries. Diagnostic workup included diagnostic DM, diagnostic DBT, ultrasound, MRI, and biopsy within 90 days of the abnormal result on screening mammography. Workup modalities and number of workup procedures were compared using differences in proportion and 95% confidence intervals (CIs). Time to diagnostic resolution between DBT and DM was compared using a log-rank test.

Results: Among 77,123 DBT and 197,589 abnormal DM screening examinations with abnormal results, the number of imaging modalities in the diagnostic pathway was similar. The first workup procedure was more often ultrasound after abnormal results on DBT compared with DM (21.1% versus 4.7%). Biopsy rates were higher for DBT versus DM (16.2% versus 14.0%; difference in proportions = 2.27; 95% CI, 1.97-2.58) with biopsies after DM versus DBT more likely surgical versus fine-needle aspiration or core (5.8% versus 3.2%; difference in proportions = 2.6; 95% CI, 2.19-3.01), resulting in a rate of excision biopsy per 1,000 screens with abnormal findings of 5.1 for DBT and 8.0 for DM. Time to diagnostic resolution was similar (median, 10 days).

Conclusions: This study revealed differences in the type of diagnostic workup pathways after abnormal results on screening DBT versus DM. Although the biopsy rate was higher after abnormal results on DBT, the biopsy type may be more invasive (surgical excision) after abnormal results on DM.