Breast magnetic resonance imaging for preoperative locoregional staging

BACKGROUND: Breast magnetic resonance imaging (MRI) has been recommended increasingly in the preoperative setting for patients newly diagnosed with malignancy to evaluate tumor extent, multicentricity, and contralateral disease. METHODS: Results of conventional imaging, breast MRI, and pathology were analyzed from 603 consecutive breast cancer patients who underwent MRI preoperatively. The focus of this retrospective study was imaging-histologic correlation. RESULTS: Reoperation for positive margins after lumpectomy occurred in 8.8% of patients. Multicentricity was identified by MRI alone in 7.7% of patients, whereas 3.7% were found to have contralateral cancer by MRI. The sensitivity of MRI was 93% in detecting multicentric disease and 88% for contralateral disease, whereas sensitivity for conventional imaging was 46% and 19%, respectively. Unsuspected disease was identified by MRI equally for invasive ductal and ductal carcinoma in situ histology, whereas multicentricity was found more frequently with invasive lobular carcinoma. CONCLUSIONS: Breast MRI is recommended for preoperative evaluation of the newly diagnosed breast cancer patient.