Reducing false positives during interpretations of ultrasound examinations for breast cancer screening

University Of Pittsburgh At Pittsburgh, Pittsburgh PA

Investigators

Abstract

? DESCRIPTION (provided by applicant): Annual screening for the early detection of breast cancer is a widely accepted practice, but it remains controversial in the United States in that both the attributable benefit and cost are continually scrutinized. One primary concern is the high number of false positive interpretations and the large number of benign biopsies being performed. There are approximately five million women being recalled for diagnostic workup in the United States each year and only approximately one in 20 are found to have cancer. Current practices for women not known to be at high risk include full field digital mammography (FFDM) and digital breast tomosynthesis (DBT). Both practices require ionizing radiation and are not optimal in terms of sensitivity for detecting invasive cancers, particularly in women with dense breasts constituting approximately 40%-45% of all screened women. Whole breast ultrasound (WBUS), whether hand held or automated, does not require radiation exposure and is significantly more sensitive to finding early invasive cancers, but also results, in today's practie, in even a higher false positive rate (~1.5X). Despite many attempts to reduce recall rates of all modalities, we have largely failed. Much of the problem may stem from the fact that there is no reference information to the interpreting radiologist (e.g., CAD for negative cases or a second opinion) that would raise his/her confidence in what not to recall. The Europeans address false positives by practicing double reading with consensus that results in approximately a 50% reduction in recalling examinations initially scored positive by one of the two readers. The larger the single reader false positive rate is and the larger the inter- observer variability, the largerthe reduction. However, this practice is not operationally feasible in the United States. Therefore, we propose to assess if a simple, cost effective, modified approach would affect radiologists during interpretations of ultrasound examinations. To test our concept, we propose to initially perform a two mode fully balanced retrospective observer study in which experienced radiologists will interpret WBUS examinations of women with dense breasts (density BIRADS 3 or 4 who are more likely to be recalled) that had been actually recalled in the clinic (positive an negative for verified cancers). In a second reading mode, the interpreting radiologists will be given independent second opinion results from low recalling radiologists. To date, this type of a possible intervention has not been investigated and it is easy to demonstrate that this approach is cost effective (professional effort) and could lead to a significant reduction in WBUS recall rates while maintaining cancer detection rates. Hence, we propose to retrospectively test the hypothesis that under this approach screening ultrasound examinations will be statistically significantly less likely to be recalled and thereby also less likely to be recommended to undergo benign biopsies, regardless of the underlying performance levels of the interpreting radiologists in question. Our primary hypothesis is that this approach, will resul in at least a 20% reduction in recall rates with no (or at worst a minimal) loss in cancer detection.