3-D mammography aids Oakland specialists in breast cancer detection

A new 3-D technology to detect breast cancer at Oakland’s Carol Ann Read Breast Health Center is helping doctors diagnose the disease earlier by allowing them to examine tissue layer-by-layer.

The medical center, part of the Alta Bates Summit Medical Center and a Sutter Health affiliate, installed tomosynthesis, also known as 3-D mammography, earlier this year. The technology enables technicians to capture both digital, two-dimensional mammograms and 3-D images using a single machine.

Breast cancer is one of the most commonly diagnosed forms of cancer besides skin cancer, striking roughly one in eight women in the U.S., according to the American Cancer Society. The Cancer Prevention Institute of California reported in 2011 that over 4,500 women are diagnosed with breast cancer in the Bay Area each year.

The new imaging technology is “the wave of the future,” said Linda Gordon, a radiologist at Alta Bates Summit. “No one will replace a standard digital unit with anything but a tomosynthesis unit anymore.”

Tomosynthesis essentially creates a three-dimensional picture of the breast using X-rays. During an exam, multiple images of the breast are acquired at different angles as the machine’s rotating arm moves in an arc around the patient. Then, the images are sent to a computer to create a series of one millimeter-thick “slices” that can be viewed as a 3-D reconstruction.

“You’re seeing the breast all superimposed on itself,” Gordon explained. “Instead of looking at a loaf of bread, you’re looking at a slice of bread. So, you can see things better.”

By contrast, digital mammograms display as a flat image, and overlapping tissue has the potential to be misidentified as cancer.

At Alta Bates, Gordon says that physicians are combining their conventional 2-D mammography with the new, 180-degree sweep of the tomosynthesis machine.

Current studies from the University of Oslo in Norway have shown that the ability to view finer details in 3-D alongside 2-D imaging has a higher invasive cancer detection rate than the latter alone.

Some detractors have pointed out that tomosynthesis results in 1.7 times the radiation dose of a conventional mammogram, but Gordon believes that the benefits outweigh the risks, adding that patients get a similar dose of radiation from getting on a plane.

While the Carol Ann Read Breast Health Center only has one 3-D unit in operation, it is raising money to replace its fleet of four digital units with tomosynthesis machines.

Gordon said that she recommends that women get screened at least every other year after they turn 40, despite a 2009 guideline from a government panel, the U.S. Preventive Service Task Force, that they start screening at 50.

“I think the real tragedy here is the personal loss in the woman between 40 and 49,” Gordon said, adding that 3-D tomosynthesis will be instrumental in reducing false positives, decreasing callbacks and detecting even smaller tumors.