CHICAGO — Compared to traditional mammography, 3D mammography—known as digital breast tomosynthesis—found 22 percent more breast cancers and led to fewer call backs in a large screening study at the Hospital of the University of Pennsylvania (HUP), researchers reported today at the annual meeting of the Radiological Society of North America (RSNA).
Conventional digital mammography is the most widely-used screening modality for breast cancer, but may yield suspicious findings that turn out not to be cancer, known as false-positives. Such findings are associated with a higher recall rate, or the rate at which women are called back for additional imaging or biopsy that may be deemed unnecessary.
Tomosynthesis, however, allows for 3-D reconstruction of the breast tissue, giving radiologists a clearer view of the overlapping slices of breast tissue. And though a relatively new technology, it has shown promise at reducing recall rates in all groups of patients, including younger women and those with dense breast tissue. This study, presented by Emily F. Conant, MD, chief of Breast Imaging the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania, is one of the largest prospective trials in tomosynthesis to date.
For the study, the research team compared imaging results from 15,633 women who underwent tomosynthesis at HUP beginning in 2011 to those of 10,753 patients imaged with digital mammography the prior year. Six radiologists trained in tomosynthesis interpretation reviewed the images.
Researchers found that, compared to conventional mammography, the average recall rate using tomosynthesis decreased from 10.40 percent to 8.78 percent, and the cancer detection rate increased from 4.28 to 5.24 per 1,000 patients, a 22 percent increase.
“Our study showed that we reduced our callback rate and increased our cancer detection rate,” said Dr. Conant, the study’s lead author. “The degree to which these rates were affected varied by radiologist. But importantly, the ratio of callback to cancer detection rate improved significantly for our radiologists.”
The overall positive predictive value—the proportion of positive screening mammograms from which cancer was diagnosed—increased from 4.1 percent to 6.0 percent with tomosynthnesis, a 46% increase.
Since October 2011, all screening mammograms at Penn Medicine now include tomosynthesis, according to Dr. Conant.
“It’s the most exciting improvement to mammography that I have seen in my career, even more
important than the conversion from film-screen mammography to digital mammography,” she said. “The coming years will be very exciting, as we see further improvements in this innovative technology.”
Co-authors are Nandita Mitra, Ph.D., Anne Marie McCarthy, Ph.D., Despina Konto, Ph.D.,
Susan G. Roth, M.D., Susan P. Weinstein, M.D., Marie Synnestvedt, Ph.D., Mathew Thomas, B.S., and Fei Wan, Ph.D.
The full RSNA press release can be found here.
Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $5.3 billion enterprise.
The Perelman School of Medicine has been ranked among the top five medical schools in the United States for the past 18 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $373 million awarded in the 2015 fiscal year.
The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania and Penn Presbyterian Medical Center -- which are recognized as one of the nation's top "Honor Roll" hospitals by U.S. News & World Report -- Chester County Hospital; Lancaster General Health; Penn Wissahickon Hospice; and Pennsylvania Hospital -- the nation's first hospital, founded in 1751. Additional affiliated inpatient care facilities and services throughout the Philadelphia region include Chestnut Hill Hospital and Good Shepherd Penn Partners, a partnership between Good Shepherd Rehabilitation Network and Penn Medicine.
Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2015, Penn Medicine provided $253.3 million to benefit our community.