Impact of Additional Mammography, as Judged Necessary by the Radiographer, on Breast Cancer Diagnosis

It has been reported that if the physician suspects cancer during standard mammography (craniocaudal and mediolateral oblique views), undertaking additional mammography under the physician’s order improves the diagnostic accuracy of breast cancer. The aim of our study was to determine whether additional mammography, as judged necessary by the radiographer, improves the diagnostic accuracy of breast cancer during mammography. Our Institutional Review Board approved the study. Mammography was performed at a single hospital in Osaka, Japan between June 2009 and March 2010. A total of 2636 individuals underwent mammography as workup. Of the 101 cases of cancer finally diagnosed, we examined a total of 75 cases were additional mammography had been undertaken. Three physicians certified as film readers by the Central Committee on Quality Control of Mammographic Screening in Japan, reinterpreted mammograms. The first reinterpretation involved only standard mammograms and the second included both standard and additional mammograms. Films were categorized by consensus on a five-point scale defining the degree to which cancer was suspected. To determine a category difference between standard mammograms alone, and both standard and additional mammograms, we used the Wilcoxon signed ranks test. A P value of <0.05 was considered significant. We evaluated the 75 cancer cases and found that the categories of cancer cases reinterpreted with standard and additional mammography was significantly higher (P <0.001) than the categories of cancer cases reinterpreted with standard mammography alone. In addition, we reinterpreted 43 cancer cases in which a lesion was not identified by the physician at the time that the mammography was ordered, and found that the categories of cancer cases reinterpreted with standard and additional mammography was significantly higher than the categories of cancer cases reinterpreted reinterpreted with standard mammography alone (P = 0.012). Undertaking additional mammography, as judged necessary by the radiographer, improved breast cancer diagnostic accuracy.