To many, digital breast tomosynthesis (DBT) is the best breast imaging technology to come along since sliced bread. But clinical enthusiasm aside, what needs to be considered before incorporating DBT into a breast imaging practice?
Plenty, according to a perspective written by Dr. Lara Hardesty, from the University of Colorado School of Medicine, and published in the American Journal of Roentgenology. She suggested that breast imaging groups consider the following factors: PACS storage and retrieval of images, radiologist and technologist training on DBT, patient selection, billing and coding, radiation dose, and marketing.
Dr. Lara Hardesty from the University of Colorado School of Medicine.The article came out of personal experience, Hardesty told AuntMinnie.com.
"When we transitioned to tomosynthesis a few years ago, I had all these questions, and I couldn't find answers to any of them," she said. "That was the impetus for writing this."
Hardesty based her perspective on the clinical use of Hologic's Selenia Dimensions device, as it was the only system cleared by the U.S. Food and Drug Administration (FDA) at the time of her writing (AJR, March 2015, Vol. 204:3, pp. 681-684).
No. 1: Storing DBT images
Substantial PACS storage space is required for a 2D full-field digital mammography (FFDM) unit plus DBT, according to Hardesty. Even if the practice doesn't keep the 15 "raw" projection images tomosynthesis acquires, and it stores only the FFDM images and DBT slices, the necessary storage space is 100 times more than what's required for an FFDM exam. With the 15 projection images, storage is 200 times what's required for FFDM exams alone.
"DBT images are much larger, 100 times that of a conventional digital mammogram, and we noticed immediately that transmission of these images from the exam room to the reading room was too slow," Hardesty said. "So we talked about this with the hospital IT department, which helped solved the problem."
No. 2: Top-notch training
Radiologists must have eight hours of training in DBT before reading the images independently -- but whoever gets the training isn't then authorized to provide training to others. Some continuing medical education (CME) firms offer this, Hardesty wrote. Technologists also require eight hours of training, which at Hardesty's institution was offered by Hologic at the time the system was installed.
"When we implemented DBT, the only radiologist training available at the time was from Hologic," she said. "Now there are for-profit CME companies that provide training."
No. 3: Particular patients
Because most practices start by operating a combination of tomosynthesis and FFDM units, it's important for a breast imaging practice to determine which of its patients will undergo DBT. Will it be all screening patients, women at high risk, or women willing to pay for the exam out of pocket? Initially, Hardesty and colleagues decided to use tomosynthesis for screening, although now the facility has four units and uses tomosynthesis for both screening and diagnosis.
"Deciding which patients get tomosynthesis needs to be based on something concrete; otherwise, patients will say, 'I'm willing to wait for that new technology,' and one of your rooms will sit unused," she said. "We started using tomosynthesis exclusively for screening. Since screening exams require 10 minutes of room time and diagnostic exams require 20, using the technology for screening allowed us to give twice as many women access to it."
No. 4: Billing and coding
Last November, the U.S. Centers for Medicare and Medicaid Services (CMS) included payment codes for tomosynthesis in its final Medicare Physician Fee Schedule (MPFS) and Hospital Outpatient Prospective Payment System (HOPPS). When Hardesty's group started using tomosynthesis, there was no code: Facilities were either covering the extra cost or asking women to pay out of pocket.
"We decided not to charge our patients for tomosynthesis, trusting that our volume would increase as we advertised the technology -- and it did," she said. "Our technologists gave patients a basic introduction to how tomosynthesis works and why it helps find smaller cancer earlier, and that boosted our volume as women told their friends and family about it."
No. 5: Reduced radiation
The mean glandular dose of combined FFDM-DBT imaging is similar to that of FFDM imaging in the American College of Radiology Imaging Network (ACRIN) Digital Mammographic Imaging Screening Trial (DMIST). In May 2013, the FDA cleared Hologic's C-View imaging software, which synthesizes 2D images from tomosynthesis data. Synthesized 2D images are not yet in widespread clinical use, Hardesty wrote, but because they offer marked dose reduction, that will most likely change in the near future.
No. 6: Mammography marketing
Offering DBT and touting its benefits pays off, Hardesty believes. At the University of Colorado School of Medicine, increased patient volume from one DBT unit allowed it to become a 100% DBT practice after 18 months. The facility's marketing efforts were largely based on word of mouth, although the group also sent out mailers describing the benefits of tomosynthesis and conducted educational sessions with referring physicians.
"At the time, we were the only facility offering tomosynthesis, and we encouraged referring physicians to send patients to us," Hardesty said.
No. 7: Keep calm
Hardesty's final point of advice to facilities looking to introduce tomosynthesis is to keep calm.
"For those who have been reading either conventional or digital mammograms for years, it takes a while to feel comfortable reading DBT exams, and that's normal," she said. "Give yourself some time and expect to feel out of your element for a while as you learn how to read tomosynthesis images and change the way you work things up."
