Objective: To assess the changes in performance measures after the introduction of tomosynthesis into clinical practice.
Materials and Methods: In an observational screening study, recall rates, biopsy rates, cancer detection rates, and positive predictive values were computed and compared for six radiologists who interpreted screening mammography studies without (n = 13,856) and with (n = 9499) the use of tomosynthesis. Analyses were performed to account for reader variability, age of participants, and whether the exam was a baseline.
Findings: The introduction of tomosynthesis systems in the clinical practice resulted in the following changes in performance measures.
- A significant 37% drop in recall rates – from 8.7% to 5.5% (p < 0.001).
- A 35% increase in cancer detection rates - from 4.0 to 5.4 per 1,000 screenings (p = 0.18).
- A 53% increase in invasive cancer detection rates - from 2.8 to 4.3 per 1,000 screening examinations (p = 0.07).
- A 115% increase in the positive predictive value for recalls - from 4.7% to 10.1% (p<0.001).
- An 11% drop in biopsy rates - from 15.2 to 13.5 per 1,000 screenings (p = 0.59)
Conclusion: The study results demonstrated a significant reduction in recall rates (~37%) along with an increase in the cancer detection rate (35% overall, 54% for invasive cancers) after the introduction of tomosynthesis in the clinical practice.