Is there a learning curve associated with interpreting DBT exams?

Exploring the performance of more than 100 radiologists, researchers found “no evidence of a learning curve” for clinically interpreting digital breast tomosynthesis (DBT) examinations.

The authors studied data from more than 106,000 DBT examinations performed from 2011 to 2017, sharing their findings in Radiology.

“The Food and Drug Administration requires eight hours of additional training for Mammography Quality Standards Act (MQSA)-qualified radiologists to interpret DBT images in clinical practice,” wrote co-author Diana L. Miglioretti, PhD, department of public health sciences at the University of California, Davis School of Medicine, and colleagues. “Prior studies have not evaluated whether DBT interpretive performance changes with clinical cumulative DBT interpretive volume (ie, whether there is a learning curve) or whether improvements in performance are sustained by radiologists over time.”

Miglioretti et al. assessed data from the Breast Cancer Surveillance Consortium, charting the impact DBT had on 104 radiologists by comparing their performance with digital mammography (DM) a year prior to DBT adoption to their DBT performance within two years after adoption.

Overall, the recall rate with DM for these radiologists was 10.4 percent and the cancer detection rate was 4.0 per 1,000 screenings. After adoption, the recall rate dropped to 9.4 percent and the cancer detection rate was “similar” at 4.6 per 1,000 screenings. The recall rate decreased for small DBT volumes (fewer than 400 studies) and remained low as the volume grew. Recall rates did decrease more in women with nondense breast tissue.

The authors also noted that the improvements were observed in breast imaging subspecialists and radiologists who were not breast imaging subspecialists. In addition, the cancer detection rates were similar for DM and DBT across the board.

“Our analysis across a large geographically diverse set of radiologists suggests that the learning curve for acquiring these skills is very short, on average, with sustained improved screening performance soon after DBT adoption; however, changes in performance with experience may vary across radiologists,” the authors wrote.