Higher radiologist reading volumes equal better digital mammography interpretations

A study published in Radiology reveals that radiologists’ annual and cumulative reading volumes raise the caliber of their performance when interpreting digital mammography images.

“During the past decade, digital mammography has replaced screen-film mammography in Western countries,” wrote lead author Solveig Roth Hoff, PhD, department of radiology, Alesund Hospital in Trondheim, Norway, and colleagues.

“However, most studies on the influence of reading volume on reading performance have reported data for screen-film mammography or a mixture of digital mammography and screen-film mammography. Our study was performed to examine the influence of annual and cumulative reading volume on radiologists’ reading performance for digital mammography in a screening program that uses independent double reading with consensus.

Roth Hoff et al. evaluated data from 2,373,433 screening examinations performed by 121 mammography subspecialist radiologists between 1996 and 2016; 6,634 cases of screening-detected breast cancer were included in the sample. All studies had occurred under the umbrella of BreastScreen Norway, a national program through which women ages 50 to 69 can receive two-view screenings every other year. Of the 121 radiologists, 25 (21%) had been in the program for less than three years; 84 (69%) for at least 5 years; and 56 (46%) for at least 10 years. Median annual digital mammogram reading volume for all practitioners ranged from 153 studies to 19,500 studies, with a median of 4,492 studies.

Multilevel mixed-effects models were used to determine how sensitivity, rate of screening-detected breast cancer (SDC), and false-positive rate (FPR) before and after consensus meeting related to annual and cumulative reading volume. Higher reading volumes, according to the research, equated with lower FPRs. For example, the FPR before consensus meeting was found to be 5.3% for radiologists who read 100 mammograms annually, 4% for radiologists who read 4,000 mammograms annually, as well as 6.7% for radiologists with cumulative mammography readings at the 500-study mark and 3.6% for radiologists with cumulative mammography readings at the 20,000-study mark.

“Annual reading volumes between 4,000 and 10,000 mammograms and cumulative reading volumes greater than 20,000 mammograms may be the most optimal volumes for achieving high reading performance in a screening program with independent double reading,” the authors concluded.