The Accuracy of Mammography, Ultrasound, and Magnetic Resonance Imaging For the Measurement of Invasive Breast Cancer With Extensive Intraductal Components

Owing to the risk of local recurrence after breast-conserving surgery, preoperative assessment including radio-logic evaluation of tumor size with intraductal component (EIC) is important. The lesion on mammography, ultrasound (US), and magnetic resonance imaging (MRI) reflected preoperative size on EIC of invasive breast cancer. MRI shows the best correlation with EIC, but cancer with calcifications of mammography shows the most accurate size of EIC.Background: The precise preoperative evaluation of radiologic tumor size with extensive intraductal component (EIC) is important. This study compared the accuracy of mammography, ultrasound (US), and magnetic resonance imaging (MRI) to measure invasive breast cancer with EIC. Methods: Between 2007 and 2012, we collected data from 6816 patients who underwent surgery for invasive breast cancer at our institution. We reviewed the postoperative surgi-cal reports of the tumors, in which the invasive tumor size and EIC were measured separately. Finally, we included 370 women who underwent preoperative mammography, US, and MRI. Each modality was retrospectively reviewed to measure the size of invasive breast cancer with EIC. The reference standard was surgical pathologic size and the accuracies of the image were evaluated. Results: Spearman's correlation coefficient for the size of invasive cancer with EIC was good between MRI (r = 0.741) and pathology, and moderate between mammography (r = 0.661) or US (r = 0.514) and pathology. Both mass and nonmass lesions showed good correlations (intraclass correlation coeffi-cient [ICC] = 0.672 and 0.612, respectively) in MRI. Furthermore, the subgroup of tumors without microcalcifications showed a higher correlation with MRI (ICC = 0.796) than with mammography (ICC = 0.620). However, the subgroup with microcalcifications showed a good correlation with mammography (ICC = 0.702) compared to MRI (ICC = 0.680) and US (ICC = 0.532). Conclusion: The lesion on mammography, US, and MRI reflected preoperative size of invasive cancer with EIC. MRI shows a higher correlation than mammography and US. However, cancer with calcifications of mammography shows a more accurate size than MRI or US.