Study on Whole-Breast Ultrasound and Digital Breast Tomosynthesis (DBT)

A recent study presented at the 2021 American Roentgen Ray Society (ARRS) meeting found that combining whole-breast ultrasound with digital breast tomosynthesis (DBT) screening exams in women with dense breast tissue lowers the rate of abnormal interpretations.

According to the study, the combination reduced the number of abnormal findings by half and may lower recall rates compared to screening with DBT alone.

Whole-breast ultrasound is a relatively low-cost, non-invasive option for screening and has been demonstrated to detect an additional 1.1 to 4.6 cancers per 1,000 patients. However, it has a high false-positive rate which increases screening recall rates. Meanwhile, DBT has been shown to decrease the mammography screening recall rate and yields more information than conventional 2D mammography.

Against the above background, Cameron Thomson, an undergraduate researcher from the University of Massachusetts, and colleagues aimed to examine how well the technologies worked together.

Study Details

The study included 12,649 DBT screening exams performed between January 2019 and December 2019. The researchers included all women with dense breast tissue who received whole-breast ultrasound during the same period.

The screenings were of female patients with heterogeneously (11,314) or extremely (1,335) dense breasts. About one-third of these women (4,115) underwent DBT only and the other two-thirds (8,534) underwent concurrent DBT and whole-breast ultrasound.

Screening whole-breast ultrasound was performed by trained technologists and interpreted online by radiologists on-site to check abnormal findings, which were represented by BI-RADS classification. DBT studies classified as BI-RADS 0, 3, 4, and 5 were considered to be abnormal, while BI-RADS 1 and 2 were classified as normal. There were no BI-RADS 0 studies among the whole-breast ultrasound, so abnormal studies were defined as 3, 4, and 5.

Key Findings

• The addition of whole-breast ultrasound to DBT reduced the overall rate of abnormal findings from 14% to 6.7%; this represents a twofold reduction in the abnormal interpretation rate for women with dense breast tissue.
• This reduction occurred even as ultrasound found an additional 2.9% of suspicious findings that had been missed with DBT alone.
• The team said findings like these are important, as women with dense breast tissue can benefit from additional cancer detection without adverse false positives.

"These findings are important as this potentially permits women with dense breast tissue the opportunity to benefit from additional cancer detection without the fear of increased adverse, abnormal interpretation rates when opting for supplemental screening with whole-breast ultrasound," Thomson said.