Last summer brought something of a media moment for mammography in the U.S. The spotlight shone on the star—3-D imaging for breast-cancer screening—after the Journal of the American Medical Association published a study showing that tomosynthesis, when added to digital mammography, is a natural at catching invasive cancers while exposing false positives as impostors.
Never mind that the “overnight sensation” had been in use in the States ever since it won FDA approval back in 2011. The press coverage following the JAMA study was both notably wide and vastly positive, making it hard to miss even for casual followers of health news.
Meanwhile, for those familiar with the territory, the study delivered a welcome moment of unity. Worldwide, heated disagreements have raged for years over various considerations related to breast-cancer screening. Stakeholders and experts continue to debate, for starters, when women should begin getting regular screenings for breast cancer, how close together the screenings should be scheduled and which technology should be used in which cases.
Today those discussions continue to simmer. They may never be settled by consensus. Though 3-D breast tomosynthesis has been available outside of the U.S., it is not ubiquitously utilized as a screening tool.
However, like a proven yet fresh face on the red carpet, 3-D tomosynthesis continues to elicit unmistakable enthusiasm among radiologists who specialize in breast imaging. And their keenness on the technology continues to provide a much-needed rallying point in the winnable war against breast cancer.
Talk leads to action
For Donna Plecha, MD, director of breast imaging at University Hospital Case Medical Center in Cleveland and a co-author of the JAMA study, last summer’s spotlight may have found another “hot” medical technology to celebrate. But the reading tools for making the most of 3-D tomosynthesis have continued to improve.
Plecha says she is especially pleased with how well her Hologic 3-D “tomo” scanner has come to mesh with her Sectra PACS.
“When we first went to tomo, I felt like we were stepping backwards a little bit because we temporarily had to bring in another workstation,” she explains. That feeling didn’t last long, as the two companies worked together quickly to iron out the compatibility wrinkles.
“One of the reasons we picked Sectra as our PACS years ago, when we first went digital, was that it made it possible to view all images on a single workstation, regardless of which manufacturer’s imaging system we were using,” says Dr. Plecha. “We had different vendors’ mammogram machines at different locations, so it was nice to have one PACS to work on in all our locations.”
Meanwhile, says Plecha, the Sectra PACS enables reads of studies from multiple modalities at one station. “We’re using it to read not only tomo but also our MRIs and our ultrasounds and everything that our patients get for breast,” she says. “And then we can look at other things too, such as CTs and x-rays. We can look at all studies the patient has had without switching workstations.”
In the JAMA study, Dr. Plecha and other researchers compared data on more than 280,000 women who only had digital mammograms with more than 170,000 women who had both 2-D and 3-D imaging. They found that adding the 3-D insights led to the detection of 4.1 invasive cancers per 1,000 exams—a startling improvement over the 2.9 per 1,000 detected by digital mammography alone.
Also encouraging was the rate of call-backs for additional imaging or do-overs, where those unwanted numbers dropped from 107 per 1,000 exams to 91 per 1,000.
“Tomosynthesis added to digital mammography is the new mammography,” says Dr. Plecha, “and it is better than the old mammography. It has addressed some of the issues that old mammography has been criticized for, including that we call back too many patients [over false positives]. Today we have fewer false alarms, which can be very stressful for patients, and the cancers we are finding are invasive cancers which are the ones we are hoping to find at an early stage.”
Real hope, not hollow hype
Indeed, for some radiologists, 3-D tomosynthesis is reason enough to continue celebrating even after the music has died down.
Marisa Weiss, MD, president and founder of BreastCancer.org and co-author of Living Well Beyond Breast Cancer: A Survivor's Guide for When Treatment Ends and the Rest of Your Life Begins, recalls the first time she saw a screening image produced by 3-D tomo.
“It was exciting and hopeful,” says Dr. Weiss, who likens using 3-D tomo to searching for a lost dog on foot rather than by car. Others have compared it with seeing right through the cover of a book to read its very pages. “There is a group of women for whom regular mammography is not specific enough or careful enough. The use of 3-D tomography is a more thorough and effective way to screen women who are at high risk, or women who have dense breast tissue or a family history of cancer or other risk factors. It is those women who are most likely to derive the benefit.”
Where a standard, 2-D digital mammogram relies on flat X-ray pictures taken from the top and side of each breast, 3-D tomosynthesis uses multiple X-ray “slices” of 1 millimeter each. The radiologist can view one slice at a time or all together, digitally configured to give a full 3-D view.
Such complementarity of technologies, observers agree, is sure to lead to a marked uptick in the adoption of breast tomosynthesis in the U.S. So far, around 1,100 hospitals and imaging centers have purchased a system, according to the healthcare-research firm MD Buyline. And, this year, multiple manufacturers’ tomosynthesis systems were introduced.
Knowledge is power
One concern raised over the JAMA study appeared as an editorial in the very same issue. “The message to women and their physicians,” the editorial stated, “has become more complex and confusing.”
Dr. Plecha concedes the point while countering that it’s not the final word. Women today face a baffling array of competing and contradicting advice on breast-cancer screening, she says, “but there is also more out there from which to get the information they need. An educated patient has to be her own best advocate.”
It’s important that physicians have the tools available to see and compare the results of all the studies they choose to utilize for each individual patient seen for breast cancer screening.