Digital Breast Tomosynthesis Increases Cancer Detection and Reduces Recall Rates
Compared to traditional mammography, three-dimensional (3D) mammography—known as digital breast tomosynthesis—found 22% more breast cancers and led to fewer call-backs in a large screening study at the Hospital of the University of Pennsylvania, researchers reported today at the 99th Scientific Assembly and Annual Meeting of the Radiological Society of North America.
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. These false-positives 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 3D reconstruction of the breast tissue, giving radiologists a clearer view of the overlapping slices of breast tissue. This relatively new technology has shown promise at reducing recall rates in all groups of patients, including younger women and those with dense breast tissue. The current study, presented by Emily F. Conant, MD, Chief of Breast Imaging in the Department of Radiology at the Perelman School of Medicine at the University of Pennsylvania and the study’s lead author, is one of the largest prospective trials in tomosynthesis to date.
Study Details
For the study, the research team compared imaging results from 15,633 women who underwent tomosynthesis at the Hospital of the University of Pennsylvania 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% to 8.78%, and the cancer detection rate increased from 4.28 to 5.24 per 1,000 patients, a 22% increase.
“Our study showed that we reduced our callback rate and increased our cancer detection rate,” said Dr. Conant. “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% to 6.0% with tomosynthnesis, a 46% increase.
Dr. Conant is a consultant for Hologic, Inc.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
