DBT screening shows higher accuracy and detects more invasive cancers, study finds

In a study published in Radiology, researchers conclude that digital breast tomosynthesis (DBT) has improved breast cancer screening performance in community practice, and identifies more invasive cancers, compared to digital mammography.

Christoph I. Lee, MD

“Our study demonstrated that more radiologists in U.S. community practice are meeting recommended performance standards with digital breast tomosynthesis than they did with digital mammography,” explained lead author Christoph I. Lee, MD, professor of radiology at the University of Washington (UW) School of Medicine, director of the Northwest Screening and Cancer Outcomes Research Enterprise at UW, and adjunct professor of health systems and population health at the UW School of Public Health. “This is good news for women and breast cancer screening, as digital breast tomosynthesis has quickly become the most popular breast cancer screening modality in the U.S.”

After gaining U.S. Food and Drug Administration (FDA) approval in 2011, DBT was adopted in the U.S. As of September 2022, 84% of all mammography screening facilities in the U.S. had DBT units.

Experts say that breast cancer mortality reduction from routine screening is contingent upon radiologists’ interpretive performance. Since the Mammography Quality Standards Act was enacted in 1992, screening facilities and interpreting radiologists have been required to meet minimum quality standards. Beginning in 2006, the Breast Cancer Surveillance Consortium (BCSC)—a collaborative network of breast imaging registries—has published screening performance benchmarks.

To establish performance benchmarks for DBT screening and evaluate performance trends over time in U.S. community practices, the research team collected DBT screening exams from five BCSC registries between 2011 and 2018.

Figure 1. Flow diagram shows selection criteria for study patients. DBT = digital breast tomosynthesis, DM = digital mammogram.

Researchers noted that performance measures included abnormal interpretation rate, cancer detection rate, sensitivity, specificity and false-negative rate.

The study reported that compared to BCSC digital mammography screening exams from the same time period and previously published BCSC and National Mammography Database performance benchmarks, all performance measures were higher for DBT except sensitivity and false-negative rate, which were similar to concurrent and prior digital mammography performance measures.

“Radiologists appear to perform better with digital breast tomosynthesis and have higher accuracy on screening 3D mammograms than 2D mammograms across U.S. practices,” commented Lee. “As this becomes the mainstay screening modality, we hope to see improved screening outcomes for women.”

He also notes that these benchmarks are also vital for the emerging field of artificial intelligence.

“Any new AI tools aimed at improving mammography accuracy will have to revise their own performance goals based on the improved radiologist performance with DBT,” he concluded.