Implementing digital breast tomosynthesis (DBT) at a breast center doesn't appear to negatively affect screening throughput, even though the modality's imaging and interpretation times can be longer than those of conventional mammography, according to a study published in the November issue of the American Journal of Roentgenology.
The findings address concerns about breast cancer screening capacity, as the number of imaging facilities offering screening has decreased over the past decade -- and the number of available mammography machines per 10,000 women ages 40 and older has decreased, wrote a team led by Dr. Christoph Lee of the University of Washington.
"As DBT is adopted into clinical practice, it is uncertain whether the already shrinking number of imaging facilities can maintain their screening capacities," the group wrote. "DBT requires a longer imaging acquisition time ... [and] is associated with a doubling of the radiologists' interpretation time. ... Understanding facility-level volume changes associated with the adoption of DBT is a critical step in determining whether additional barriers to screening access may exist."
Lee's group investigated whether the adoption of DBT had a negative impact on facility-level screening volumes at facilities in the Breast Cancer Surveillance Consortium (BCSC) that began using the technology between 2011 and 2014 (15 of 83 facilities, or 18.1%). Of these 15 facilities, 73.3% had no academic affiliation, 80% were nonprofit, and 66.7% were general radiology practices.
All 15 facilities incorporated a single DBT unit; half of these replaced a digital mammography unit with the new DBT device, while the other half kept existing digital mammography units active while adding the DBT unit to their operations (AJR, November 2018, Vol. 211:11, pp. 957-963).
The researchers found that facility-level monthly screening volumes were actually higher after DBT adoption, with an overall increase of 7.2% in mean monthly volumes across facilities.
They also noted the following:
- More than half of the facilities that implemented DBT (53.3%) saw a change of 5% or less in the total mean monthly screening volume (either increase or decrease) when comparing the pre- and postadoption periods.
- No facilities experienced a decrease of more than 10% in monthly screening volume.
- The three facilities that kept their existing digital mammography units and added a DBT device to the workflow saw an increase of more than 20% in the mean monthly screening volume after DBT was implemented.
What's the bottom line? DBT doesn't negatively affect screening volume -- in fact, it seems to increase it, Lee and colleagues concluded.
"Contrary to concerns regarding increased image acquisition time and interpretation time that could theoretically decrease screening capacity, monthly screening examination volumes were maintained and slightly increased," the group wrote.
