What Is Breast Tomosynthesis?
Breast tomosynthesis is a new technology in digital mammography that allows radiologists to view tissue detail in a way never before possible. While standard mammograms take two images of the breast, one vertical and one horizontal, in breast tomosynthesis, the X-ray machine moves in an arc over the breast, taking many images from different angles. Rather than the flat image of a traditional mammogram, breast tomosynthesis creates a three-dimensional view of the breast that can be examined a millimeter at a time, making it easier to discern fine details. For this reason, breast tomosynthesis is often referred to as 3-D mammography.
What Are the Benefits of 3-D Mammograms?
Although narrow clinical studies have illustrated 3-D mammography’s superiority over traditional digital mammography alone in detection and false positive rates, these findings are bolstered by a recent study published in The Journal of the American Medical Association. The new report cites data from thirteen breast centers, providing a much more diverse sample population than previous studies. According to the report,
“Addition of tomosynthesis to digital mammography was associated with a decrease in recall rate and an increase in cancer detection rate.”
The researchers followed nearly 500,000 patients and found significant improvements in detection rates, especially for invasive cancers, and in recall rates. With the addition of breast tomosynthesis, cancer detection increased 29% over digital mammography alone, and detection of invasive cancers increased 41%. At the same time, while 106 women per 1000 who underwent 2-D digital mammography alone were called back for further testing, only 89 of 1000 who received breast tomosynthesis were recalled. Overall, 3-D mammography resulted in a 15% reduction in false positive results.
What this means for mammography patients is that the use of 3-D imaging has the potential to reduce their chances of being called back for additional tests while increasing the likelihood that existing cancer, and especially invasive cancer, will be identified in screening. Reducing callbacks and false positives translates into less money spent on unnecessary testing and less stress induced by misleading or inconclusive mammogram results.
Mammography and Breast Density
Because 3-D mammography allows the radiologist to examine breast tissue in much finer detail, it is an especially valuable tool for women with dense breasts. Dense breasts contain less fat and more fibrous and glandular tissue. Tumors and dense breast tissue both appear white on a mammogram, making it difficult to identify cancer. In fact, women with dense breasts are nearly twice as likely to receive a false positive result than a woman with fatty breasts. At the same time, women with dense breasts can have a higher risk of developing breast cancer. Breast tomosynthesis can help find cancer earlier in this population that has a greater need of advanced detection methods.
Getting a 3-D Mammogram
Although the Food and Drug Administration approved breast tomosynthesis in 2011, most insurers are still not covering the cost. Iowa Radiology offers breast tomosynthesis to our mammography patients for an additional charge of $40. The exam time is about the same as with digital mammography alone, as 3-D and 2-D images are obtained at the same time. No additional compression or adjustment of the breast is necessary. If you would like to discuss adding breast tomosynthesis to your next screening mammogram, call and ask for a mammography technologist. We are happy to answer any questions you may have.
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 Friedewald, et al. “Breast Cancer Screening Using Tomosynthesis in Combination With Digital Mammography.” JAMA. 311.24 (2014): 2499-2507.)
 “JAMA: Adding Tomo to Mammography Finds More Cancer.” AuntMinnie.com. 24 June 2014, Web. 9 July 2014.
 Kathleen Doheney, “Adding 3-D Mammograms May Improve Accuracy.” WebMD, 20 November 2012. Web. 10 July 2014.