The use of batch reading to improve the performance of screening mammography

The objective of our study was to prove that batch reading of screening mammograms can reduce recall rates without sacrificing cancer detection.

We analyzed recall rate, cancer detection, minimal cancer detection, detection of low-stage cancer, and tumor size from consecutive screening mammography examinations from October 2001 to July 2003. The initial 7,984 mammograms were interpreted in the midst of a busy breast imaging practice. Although these studies were not read online, the interpretations were often interrupted for telephone calls, procedures, and diagnostic mammograms. The remaining 1,538 studies were interpreted after the institution of dedicated uninterrupted batch reading.

Recall rates were 20.1% before and 16.2% after the introduction of batch reading (p < 0.001). Cancer detection rates were not significantly different: 5.6 cancers were detected per 1,000 examinations without and 7.2 were detected per 1,000 with batch reading. Prognostic factors for breast cancers diagnosed between these groups also were not significantly different. Of the screening-detected cancers diagnosed before batch reading, minimal cancers comprised 67% and low-stage cancers accounted for 76%. Of the cancers diagnosed using batch reading, 73% were minimal and 91% were low stage. The mean size of cancers, 11.7 mm without batch reading and 9.1 mm with batch reading, also showed no statistically significant difference.

Our experience shows that batch reading can significantly reduce screening mammography recall rates without affecting the cancer detection rate or the proportion of cancers diagnosed with favorable prognostic indicators.