Here’s how good the tests are at detecting cancer and preventing false positive results.
Women going in for routine mammograms are increasingly being screened with a new type of imaging tool: digital breast tomosynthesis.
The new technology, which is sometimes referred to as 3-D mammography or D.B.T., lets doctors look at the breast in greater detail. Some research has shown that it can detect slightly more cancers with fewer false positive results than conventional mammograms — though it’s still too early to know whether these benefits will translate to fewer cancer deaths.
“By the time we know the answer, this will already be the default technology,” said Dr. Ilana Richman, an assistant professor at the Yale School of Medicine who has studied adoption of the procedure across the United States. Almost half of all mammography units in the country are now tomosynthesis units, and more than 90 percent of all breast imaging facilities in the country offer the procedure, according to federal data.
How does tomosynthesis work?
The procedure is similar to a regular mammogram, when the breast is compressed between plates and a machine takes X-rays. But in D.B.T., a machine takes multiple X-rays across the breast and reconstructs them into slices to create a quasi-3-D picture. In contrast, traditional mammography takes one X-ray of the entire breast from a top view and another from a side view and creates a two-dimensional picture.
Doctors often compare it to looking at slices of bread. “Digital breast tomosynthesis allows us to deconstruct the breast into layers to make it easier to see,” said Dr. Kathryn Lowry, an associate professor of radiology at University of Washington School of Medicine and a physician at Fred Hutch Cancer Center.
Seeing those additional layers can sometimes help reveal potentially cancerous masses hiding behind other tissue — or make clear when an abnormality is actually nothing, Dr. Richman said.