Improving the Accuracy of Breast Imaging

Breast tomosynthesis more accurately detected breast cancer and reduced recall rates

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The gold standard for breast cancer screening is digital mammography. Unfortunately, false-positives, which appear to be breast cancer but turn out not to be, are not all that unusual for mammography.

A more powerful breast imaging system appeared to help eliminate some of these uncertainties.

In a new study, digital breast tomosynthesis, which creates a 3-D image of the breast, was more accurate in detecting breast cancers and reducing recall rates than digital mammography.

"Find out what kind of equipment is used for your mammography."

Emily F. Conant, MD, chief of breast imaging at Hospital of the University of Pennsylvania (HUP) in Philadelphia, led a team of researchers in evaluating the effectiveness of digital breast tomosynthesis (DBT) in detecting true breast cancers.

Digital mammography is now the standard for breast cancer screenings. These images, however, can be compromised by various factors that can produce suspicious looking areas. This lack of clarity results in recalling women for additional testing.

The newer digital breast tomosynthesis technology uses ionizing radiation, as does digital mammography, to create a 3-D image that can be viewed as sequential slices of the breast. The resulting images are clearer for all types of patients, including young women and women with dense (more fibrous tissue than fat) breasts.

Because DBT is new, it’s currently used primarily as a follow-up screening. But HUP has been using the technology for all breast screenings for two years now.

For this study, Dr. Conant’s team reviewed 15,633 DBT images taken since October 2011 and compared them to 10,753 digital mammography images from a year earlier.

Six radiologists who are trained to interpret DBT reviewed the images.

The comparison showed that DBT was superior to digital mammography in detecting true cancers. DBT detected 5.25 tumors per 1,000 patients, compared to 4.28 cancers per 1,000 found by digital mammography.

DBT also reduced recall rates, with retesting necessary in 8.78 percent of DBT images versus 10.40 percent of digital mammograms.

The proportion of positive screening mammograms that led to cancer diagnosis increased from 4.1 percent with digital mammography to 6.0 percent with DBT.

DailyRx News spoke with the inventor of digital breast tomosynthesis, Daniel B. Kopans, MD, professor of radiology at Harvard Medical School and senior radiologist in the Breast Imaging Division at Massachusetts General Hospital.

“When I invented it for breast evaluation I recognized that it would reduce the interference that is caused by normal tissues when we read 2-dimensional mammograms, and make cancers more easily seen. The fundamental advantage is that radiologists can quickly understand the images since they are still mammograms — only better,” Dr. Kopans said.

The results of this study were presented at the annual meeting of the Radiological Society of North America (RSNA). All research is considered preliminary before being published in a peer-reviewed journal.

Dr. Conant disclosed a financial tie with Hologic, Inc., a manufacturer of digital breast tomosynthesis systems. No other conflicts of interest were declared.

Review Date: 
December 2, 2013
Last Updated:
December 30, 2013