Tomosynthesis outperforms mammography in breast cancer detection, recall rate reduction

Digital breast tomosynthesis (DBT) has showcased significantly improved performance metrics for breast cancer screening in comparison with 2D digital mammography (DM) in community radiology practice, according to a study published online June 11 by the American Journal of Roentgenology.

Concerns about overdiagnosis, false-positive recalls from screening and low positive predictive value from biopsy after abnormal screening in breast cancer screening may be quelled by 3D DBT. Lead author Julianne S. Greenberg, MD, of Washington Radiology Associates in Fairfax, Va., and colleagues conducted a retrospective study at their multisite community-based practice, the largest of its kind to date. As early adopters of 3D DBT, the authors sought to compare the performance of 3D DBT with that of conventional 2D DM alone in a high-volume population-based breast cancer screening program.

During the study, performance outcome measures were assessed for 14 radiologists who interpreted over 500 screening mammography 3D DBT studies after the adoption of tomosynthesis. The outcomes from screening mammography using DBT in 23,149 patients were compared with outcomes from using DM in 54,684 patients.

Patients screened with 3D DBT had a relative change in recall rate that was 16.1 percent lower than the patients screened with 2D DM.

The overall cancer detection rate per 1,000 patients screened was 28.6 percent greater for DBT than DM. The detection rate for invasive cancers with 3D DBT was 43.8 percent higher than with 2D DM and the positive predictive value for recalls from screening was 53.3 percent greater for 3D DBT.

No significant difference in the positive predictive value for biopsy was observed between 3D DBT and 2D DM, as evidenced by the respective values of 22.8 percent and 23.8 percent.

“A detailed analysis of the characteristics of cancers detected by DBT is a subject for future research, including evaluation of lesion size, descriptive imaging characteristics of malignant lesions, and TNM pathology staging,” wrote the authors. “Also, analyses stratified by patient age and breast density may yield useful information concerning which patient subgroups will benefit most from 3D DBT screening.”

Overall, the authors contend their results reveal screening with 3D DBT is efficacious and holds practical implications for patient care.