No woman wants to get a call that her radiologist has found a suspicious image on her mammogram, and then learn that she might need a biopsy—only to find out it was all a false alarm. Now, thanks to new technology, fewer women will get those calls.
Digital breast tomosynthesis, or 3-D mammography, is transforming breast screening by significantly reducing callbacks while picking up more cancers, and eliminating some of the fear and anxiety many women experience. All women who visit the Breast Center at Smilow Cancer Hospital at Yale-New Haven for mammography are now getting tomosynthesis over plain 2D mammography, says Liane Philpotts, MD, chief of breast imaging for the Breast Center.
“Tomosynthesis is a game-changer. It’s a win-win-win,” Dr. Philpotts says. “We have seen a 20 percent increase in cancer detection rates over 2-D mammography. In addition to that, before tomosynthesis we were calling back more than 10 percent of all women, which is a huge number. One of the immediate benefits that we have seen is that this number has been reduced by 30 percent, which is wonderful.”
3D imaging shows more detail
Tomosynthesis was approved by the Food and Drug Administration in 2011 after trials were completed at Yale and four other medical centers. It is the first technology to deliver 3-D images in mammography, allowing radiologists to view the breast in detailed 1-millimeter slices, instead of as a large single image. Dr. Philpotts has likened it to leafing through the pages of a book.
One patient had tomosynthesis screening at the Breast Center for the first time in June. Her radiologist saw a suspicious lesion, so the woman had an ultrasound and then a biopsy, which found a 3-centimeter lump at an early stage. Doctors treated it with a lumpectomy and radiotherapy, followed by hormone therapy. “I felt very lucky,” she says. “You couldn’t see it, you couldn’t feel it. It wasn’t there the year before as far as we know. Regular mammography would not have caught this,” she says.
“For a screening, tomosynthesis was perfect. It’s very quick. They didn’t take a bunch of films, no more than one shot of each breast. For women who don’t like being squeezed and squashed, that makes a difference,” she says.
Refining the approach
Yale’s diagnostic radiologists are currently using breast tomosynthesis in combination with 2-D screening mammography, as the larger picture of the breast is still necessary. However, researchers are working on ways to extract a 2-D image out of the 3-D data, known as 2-D synthetic mammography. When that happens, there may no longer be a need for the 2-D examination, Dr. Philpotts says. This will lessen the concern over the small increased amount of radiation patients are exposed to when using 3-D and 2-D together.
As far as finding cancers, “everything depends on how well you characterize a lesion, and we can characterize lesions better,” Dr. Philpotts says. “You get a better view of the margins (the area at the edge of the tumor), which makes for a better assessment.”
Traditional mammograms, on the other hand, can’t always distinguish cancerous areas from harmless ones. This is especially problematic in patients—usually younger women—with dense breasts, which have more glandular than fatty tissue. “Fat we can see through,” Dr. Philpotts explains. “If a patient has a lot of glandular tissue, it is going to be white” on an image. But cancer cells also appear white, so “It’s hard to see,” she says. “Cancer can be hiding. This is one of the limitations of mammography.”
To demonstrate, Dr. Philpotts calls up a 2-D image of a whole breast on one of two adjacent monitors. It shows a mass of white in the middle. Dr. Philpotts is suspicious of the mass, but the blurriness won’t let her draw any conclusions. She switches the display on the monitor, which costs $100,000 and can display the images individually or unfurl them, movie-like, like a high-tech zoetrope. Each slice shows an area deeper in the tissue. “It’s as if you can see through the breast,” she says. As she progresses, she spots a telltale spidery lesion that indicates cancer.
Dr. Philpotts and colleagues are still studying the best way to use tomosynthesis. Their most recent findings, published online this summer in the journal Radiology, showed that, as far as accuracy, it is most beneficial for patients in the 40-to-50 age range and those with dense tissue, but it also has significant benefits for patients into their 70s.
“The bottom line is every patient really does benefit,” she says.
To contact Yale-New Haven Hospital Diagnostic Radiology call 203-688-1010.