New 3D Technology Improves Breast Screening Accuracy
Mammograms have been the gold standard for detecting breast cancer for more than 20 years, but a new technology promises better detection and fewer false-positive results
--by Suzanne Boothby
Adding a three-dimensional breast imaging technology called tomosynthesis to standard digital mammography increased radiologists’ diagnostic accuracy and reduced the rate of false positive results, according to a new study published in Radiology.
Breast tomosynthesis involves taking multiple, low-dose images inside the breast, and can produce a more accurate reconstruction of the breast than conventional mammography alone.
“This is the first major advance in breast imaging and breast cancer screening since the development of breast MRI," said lead researcher Elizabeth A. Rafferty, M.D., director of Breast Imaging at the Avon Comprehensive Breast Center at Massachusetts General Hospital in Boston. "The beauty of tomosynthesis is that it addresses two major concerns with screening mammography: missed cancers and false positive rates."
Approved by the FDA in 2011, this 3D imaging modality captures high-resolution images during a short scan, similar to a computed tomography (CT) scan, and helps doctors see more hard-to-interpret areas with breast tissue overlap.
Mammography reduces breast cancer mortality in women between the ages of 40 and 74, according to the National Cancer Institute. However, as many as 30 percent of breast cancers are not detected by mammography, and an additional eight to 10 percent of women who undergo a screening mammogram are recalled for further testing when no cancer is present (called a false positive result).
The Expert Take
Researchers say this new technology could have a huge impact on invasive cancer detection.
"Almost all of the gains in diagnostic sensitivity with the combined modality were attributable to the improved detection and characterization of invasive cancers, which are the cancers we are most concerned about because of their potential to metastasize (spread)," Dr. Rafferty said.
With the addition of breast tomosynthesis to standard digital mammography, false positive recall rates significantly decreased in the study population.
Source and Method
The study involved 1,192 women recruited from five sites, including 780 screening cases and 217 women who needed pre-biopsy breast imaging. Each woman underwent a standard digital mammogram followed by breast tomosynthesis. The total radiation dose for the combined procedure was less than three milligray, which is the FDA limit for a single mammogram.
Compared to digital mammography alone, the use of both a standard mammogram and tomosynthesis resulted in increased diagnostic accuracy for all radiologists in the study.
Combining mammograms with tomosynthesis can enhance the accuracy of breast cancer screenings. Both digital mammography and breast tomosynthesis can be performed on the same equipment in rapid succession, with little additional radiation exposure.
Duke University researchers are currently conducting a study examining early detection of breast cancer using tomosynthesis imaging. Results are expected in 2013.
A 2007 study found that breast tomosynthesis provides a more accurate evaluation of lesions by enabling better differentiation between overlapping tissues.