Does computer-aided detection (CAD) contribute to the performance of digital mammography in a self-referred population?

Abstract

Background Recent evidence suggests that computer-aided detection (CAD) may have a negative impact on the interpretation of mammography—this necessitates timely evaluation of CAD in practice. We report a retrospective study of the incremental effect of CAD on the accuracy of full-field digital mammography (DM) as applied prospectively in breast assessment. Methods: Subjects were all consecutive women attending a self-referral breast centre in Florence between September 2005 and January 2007 (N = 3,425). DM was reported without, then with, CAD according to a standard protocol; all mammograms recalled on the basis of either the radiologist’s reading alone, or the radiologist’s reading after viewing CAD, were recalled to assessment. Results Overall recall rate (RR) was 13.1% and 107 cancers were diagnosed (90 invasive cancers, 8 DCIS, 9 malignant on cytology). The use of CAD allowed the additional detection of 5 cancers (three invasive cancers, one DCIS, one malignant on cytology) and caused one additional benign surgical biopsy, with a relative RR of 4.9%, and an incremental RR of 1.17%. The cancer detection rate (CDR) of DM interpreted with the use of CAD was 3.12% and did not significantly differ from the CDR of 2.9% based on DM without CAD (χ² = 3.2, P = 0.07). Conclusion While the increase in CDR with the use of CAD only approached statistical significance, representing modest gains in absolute terms, the incremental number of cancers detected justifies the incremental recall and benign surgical biopsy attributable to CAD use. In our clinical setting, these data suggest more benefit than harm in using CAD with DM, and we will continue the use of CAD with ongoing monitoring of patient outcomes.