Recent Studies Support the Effectiveness of Digital Breast Tomosynthesis (DBT)

Digital breast tomosynthesis, also known as DBT, is a further evolution of digital mammography in which a series of low-dose projection images of the breast are obtained at different angles. According to a recent, multicenter study, published in JAMA Oncology in February 2019, it can lead to better breast cancer detection and fewer false-positive recalls compared to digital mammography.

At UCSF Radiology, we know that conventional mammography is certainly a life-saving tool, and DBT represents a significant step forward. It has the potential to detect some cancers at screening that are not visible by conventional mammography, the majority of which are invasive cancers. Additionally, DBT has been shown to reduce false-positive callbacks at screening. For patients referred for a breast symptom or workup of an imaging finding, DBT may enable more definitive and efficient characterization of breast abnormalities. Findings from this study further support these ideas.

The team of researchers (not from the UC San Francisco Department of Radiology and Biomedical Imaging) looked at more than 180,000 screening exams, 50,000 of which were DBT exams and nearly 130,000 digital mammograms, all taken at one of three research centers in the northeastern United States as part of the PROSPR (Populations-based Research Optimizing Screening Through Personalized Regimens) consortium. They found that, overall, DBT identified more cancers with better prognosis and generated lower recall rates for women of all ages and breast density types. In addition, researchers also found that in the subgroup of women age 40 to 49 years, "routine DBT screening may have a favorable risk-benefit ratio" which supports the idea that annual breast cancer screening should begin at age 40.

To add to this discussion, a second study was recently published in March 2019 in Radiology where a team of scientists from the U.K. evaluated the benign biopsy rate of DBT versus that of full-field digital mammography (FFDM) in women recalled after breast screening. They concluded that, when compared with FFDM, DBT can reduce the benign biopsy rate, hence reducing the "harms" or risks of screening, while also maintaining the cancer detection rate.

DBT is ready for clinical use at the Avon Comprehensive Breast Center at Zuckerberg San Francisco General Hospital & Trauma Center and at the UCSF Medical Center at Mount Zion. It will also be offered at the UCSF Medical Center at Mission Bay upon opening of the Precision Cancer Medicine Building in Fall of 2019.