Despite the demonstrated clinical benefits of digital breast tomosynthesis (DBT) for finding breast cancer, use of the technology for mammography is still inconsistent across the U.S., according to a study published online February 7 in Academic Radiology.
Why? Most likely due to variations in reimbursement and a lack of standardized guidelines, researchers from New York University School of Medicine wrote. And these factors could be preventing women from taking advantage of DBT's benefits.
"Scientific data shows that DBT is beneficial to women, but we haven't figured out the best way to implement the technology -- or even how it's being used now," lead author Dr. Yiming Gao told AuntMinnie.com.
DBT in daily practice
Even as more and more studies affirm DBT's ability to decrease recall rates and increase cancer detection, how the technology is used in daily clinical practice remains unclear, Gao and colleagues wrote. To this end, the group sought to evaluate uptake of DBT, patterns of use, and perception of the technology among practicing radiologists.
"DBT is not yet standardized in terms of approved indications, management guidelines, and evidence-based application of the [BI-RADS] lexicon," the group wrote. "So although DBT may be on the cusp of becoming an accepted clinical tool, current analysis and understanding of how DBT is actually being used in daily clinical practice ... is lacking."
The researchers sent surveys to 7,023 breast radiologists whom they identified using an RSNA database. The survey solicited information such as respondents' geographic location and practice type, length of DBT use, patient selection criteria, and recall rate (Acad Radiol, February 7, 2017).
Of the more than 7,000 surveys sent, 1,156 radiologists responded: 65.8% were from the U.S. and 34.2% were international. The majority (68.6%) of survey participants use DBT, with the following practice types represented:
- Academia: 22.6%
- Private practice: 56.5%
- Other: 21%
Survey respondents were equally likely to report use of DBT if they worked in academic practices (78.2%) versus private practices (71%), the authors wrote. Of those who reported they were not using DBT, 43% stated they planned to adopt the technology. Most of the survey participants who were using DBT said they use Hologic's system (84%), with 14.2% using a GE Healthcare system and 6.6% using a Siemens Healthineers unit.
The majority of radiologists had been using DBT between one and three years (60.2%), and most were using the technology for screening (89%) and diagnostic evaluation (92.7%). Only about 30% of survey respondents stated that they used DBT for all screening patients; those who specified particular screening criteria listed dense breast tissue, high risk status, prior imaging with DBT, and patient request for the technology.
Of the study participants, 74.6% reported that DBT decreased recall rates. There was a weak but statistically significant correlation between length of DBT use and reading time, suggesting that reading time decreases with continued DBT use, according to the authors.
The majority of radiologists (75.8%) said they still use conventional 2D mammography with DBT, Gao's team found. Of those who use synthesized 2D as part of their imaging protocol, 59.1% used it along with conventional 2D imaging rather than alone -- although 58.2% of those who do not use synthesized 2D alone plan to shift to using it in place of conventional 2D in the future.
The fact that more radiologists aren't using synthesized 2D with DBT exams was an unexpected finding, Gao told AuntMinnie.com.
"It's surprising that more people aren't using synthetic 2D, since there have been quite a few studies that show it's comparable [to conventional 2D]," she said. "You'd think since synthesized 2D cuts radiation in half, people would rush to use it -- especially since more than 80% are using the Hologic system, which has [U.S. Food and Drug Administration]-approved synthesized 2D software."
Finally, more than half of survey respondents didn't know whether DBT was reimbursed by the U.S. Centers for Medicare and Medicaid Services (CMS), and the degree of reimbursement varied widely among those who did receive payment, which the authors chalked up to continued inconsistencies in insurers' approach to DBT.
"Although the CMS has formally acknowledged DBT via the creation of current procedural terminology codes, many private insurers continue to decline payment for the examination, categorizing DBT as an investigational technique," they wrote.
Maximizing benefit?
If DBT is still a relatively limited resource, it's all the more important to determine how to maximize its clinical benefit, Gao said. Standardized protocols and consensus in the field could help make the technology more available.
"Clinical data show that DBT can be used for all screening, but if you're a small practice with only one unit, how do you figure out how best to use the technology?" she said. "There's definitely a need for more standardized protocols."
