Breast Cancer Screening Recall Rates Drop with Tomosynthesis

Digital tomosynthesis is an effective tool for reducing the recall rate in breast cancer screening, according to new research.

The findings were published online July 2012 in the journal Radiology. Digital mammography is the gold standard for breast cancer screening, but may yield suspicious findings that turn out not to be cancer. These false-positive findings are associated with a higher recall rate.

Digital breast tomosynthesis has shown potential at reducing recall rates, especially in younger women and in those with dense breast tissue. Tomosynthesis is similar to mammography because it relies on ionizing radiation to generate images of the breast. However, dissimilar to traditional mammography, tomosynthesis allows for three-dimensional (3D) reconstruction of the breast tissue, which can then be viewed as sequential slices through the breast.

“Tomosynthesis increases the conspicuity of cancers by removing superimposed and overlapping tissue from the view,” said Brian M. Haas, MD, from the Yale University School of Medicine (New Haven, CT, USA).

In the study, Dr. Haas worked with Yale’s Liane E. Philpotts, MD, and other colleagues to compare screening recall rates and cancer detection rates in two groups of women: those who received only traditional digital mammography and those who had undergone tomosynthesis screening in addition to mammography.

Of the 13,158 patients who underwent screening mammography, 6,100 received tomosynthesis. The cancer detection rate was 5.7 per 1,000 in patients receiving tomosynthesis, compared with 5.2 per 1,000 in patients receiving mammography alone. By adding tomosynthesis resulted in a 30% reduction in the overall recall rate, from 12.0% for mammography alone to 8.4% in the tomosynthesis group.

“All age groups and breast densities had reduced risk for recall in the tomosynthesis group,” Dr. Haas said. “Women with dense breasts and those younger than age 50 particularly benefited from tomosynthesis.”

Lower recall rates help decrease patient apprehension and also reduce costs from further diagnostic testing, according to Dr. Haas. Tomosynthesis has one significant drawback, however, a radiation dose about twice that of digital mammography alone. However, Dr. Haas noted that new technology approved by the US Food and Drug Administration (FDA) could reduce the dose. “The technology involves taking the tomosynthesis data and collapsing it into planar imaging that resembles 2D mammography,” he said. “It has the potential to eliminate the need for acquisition of the conventional 2D images in addition to the tomosynthesis images.”

The research group is currently comparing the tumors detected on tomosynthesis with those identified on mammography. They are also monitoring the study group for interval tumors—those that develop in the interval between screenings—to validate that the reduced recall rate associated with tomosynthesis does not resulting in missed tumors.

Related Links:
Yale University School of Medicine