The emergence of a new, powerful imaging modality is cause for both celebration and consternation, and digital breast tomosynthesis (DBT) has proven no exception to this rule, according to participants in a June 8 educational forum at the 2013 meeting of the Society for Imaging Informatics in Medicine (SIIM), held in Grapevine, Texas. Early results from sites offering DBT to their patients have been nothing short of extraordinary: X-ray Associates of New Mexico (XRANM) in Albuquerque, for instance, reports a 48% reduction in its recall rate, while the University of Pittsburgh Medical Center (UPMC) in Pennsylvania has seen a 40% increase in detection of invasive breast cancers, with a reduction in false positives of 15%. The journey to achieving these exciting results with a sustainable workflow is not without its challenges, however. In the session “Digital Breast Tomosynthesis and the Informatics Infrastructure: How DBT Kills Your PACS/VNA,” a broad group of 24 physicians, informaticists, and vendors met to discuss the challenges of incorporating the new modality into both radiologist workflow and existing informatics infrastructure.
Workflow Issues Michael Linver, MD, of XRANM, observes that his facility’s recall rate has plummeted since the implementation of DBT. “Our recall rate is down 48% for patients who had DBT (versus those who did not), which cuts way back on the number of patients we’re having to see on the diagnostic side,” he observes. “The problem, for us, was interpretation. DBT can take five times as long to read as a regular screening mammogram, and that was a bit of a hardship. It makes our days, as radiologists, even longer.” With time of the essence, alternating between a standard PACS workstation and the proprietary Hologic workstation is not a viable option, for many facilities. The issue, as outlined by speaker Donna Plecha, MD, a radiologist with University Hospitals Case Medical Center (UHCMC), Cleveland, Ohio, is that the data issued by the Hologic breast-tomosynthesis system are in a proprietary format. When her organization began reading DBT studies, in September 2011, “Our PACS couldn’t accept the tomosynthesis images, so we’d read 2D mammograms on our Sectra PACS, get out of our chairs, sign in at the Hologic workstation to read the 3D images, and do a screen capture of one marked image to send to our PACS,” Plecha says. Speaker Margarita Zuley, MD, director of breast imaging at UPMC, reports similar problems. She outlines the key challenges related to dealing with tomosynthesis images: sizing, outside image management, orientation, procedure codes, and the creation of synthetic 2D images from 3D datasets. “Some PACS can store DBT images but cannot display them, and some can’t even store them,” she notes. Even for PACS platforms that can view and store DBT images, projection data remain proprietary to Hologic, she adds. Now, however, vendors are rushing to make DBT images compatible with their applications. One of the first to achieve this goal was Sectra; by collaborating with Hologic, the company was able to integrate DBT images into its breast imaging platform, enabling physicians to read them side by side with more traditional 2D screening mammograms. “We’ve been able to read screening DBT images on our Sectra PACS since August 2012,” Plecha says. “We’re able to make hanging protocols on the 2Ds that we can compare with the 3Ds, as well as with prior exams.” Stamatia Destounis, MD, attending radiologist at Elizabeth Wende Breast Care (EWBC), Rochester, New York, reports a similar challenge and solution. “Having to read on the Hologic workstation was a real workflow breakdown,” she says. “Sectra was able to allow us to view the 3D images on our mammography PACS and look at them side by side with prior exams and prior 2D mammograms. Reading the combined images probably still takes twice as long, but our prior workflow, with the Hologic workstation, really limited how many DBTs we could do. Having them integrated into the PACS represents a real clinical advantage. This is the way it should be done.” All three facilities have seen inspiring results from offering DBT, making the extra work well worth it. “We’ve found a close to 50% reduction in recall rates with combined 2D and 3D screening, and we are identifying more cancers, including small masses, smoothly outlined masses near the nipple, and calcifications,” Destounis says. Plecha adds, “It’s challenging, but it’s worth it.