Breast MR Imaging Screening in Women with a History of Breast Conservation Therapy

Purpose: To retrospectively investigate the outcomes of single-screening breast magnetic resonance (MR) imaging in women who had a history of breast conservation therapy (BCT) for breast cancers and who had previous negative mammography and ultrasonographic (US) findings. Materials and Methods: This study was institutional review board-approved and informed consent was waived. Between January 2008 and March 2012, 607 consecutive women (median age, 48 years; age range, 20-72 years) who underwent BCT for breast cancer, had negative mammography and US findings, and underwent subsequent screening breast MR imaging were studied. Of the study population, 91.8% (557 of 607) patients underwent preoperative MR examinations. Cancer detection rate, characteristics of detected cancers, positive predictive value (PPV), sensitivity, and specificity were assessed. Multivariate logistic regression analysis was performed to identify independent clinical-pathologic factors associated with women with cancers detected by using MR imaging. Results: Eleven cancers (eight invasive, three ductal carcinoma in situ; median invasive size, 0.8 cm; range, 0.4-1.4 cm; all node negative) were additionally detected with MR imaging in 607 women (18.1 cancers per 1000 women). PPV for recall, PPV for biopsy, sensitivity, and specificity were 9.4% (11 of 117 examinations), 43.5% (10 of 23 examinations), 91.7% (11 of 12 examinations), and 82.2% (489 of 595 examinations), respectively. At multivariate analysis, the independent factors associated with women with MR-detected cancers were age younger than 50 years at initial diagnosis (P < .001) and more than a 24-month interval between initial surgery and screening MR imaging (P = .011). Conclusion: Single-screening MR imaging depicted 18.1 additional cancers per 1000 women with a history of BCT. Multivariate analysis revealed age younger than 50 years at initial younger than 50 years. (C) RSNA, 2014