Additional magnetic resonance imaging-detected suspicious lesions in known patients with breast cancer: Comparison of second-look digital tomosynthesis and ultrasonography

Purpose: The aim of the study was to compare the performances of second-look digital breast tomosynthesis (DBT) and ultrasonography (US) for additionalmagnetic resonance imaging (MRI)-detected suspicious lesions in patients referred for breast cancer. Methods: Fifty-five patients (52.5[9.3] years) with breast cancers newly diagnosed at a referring hospital underwent MRI and afterward DBT and US in our institution. The frequency for detecting additional MRI-detected suspicious lesions on DBT and US and performances of DBT and US were compared. Results: Of 37 additionalMRI-detected suspicious lesions, 27 were detected on DBT and/or US; 2 were detected on both DBT and US, 1 was detected only on DBT, and 24 were detected only on US. Ultrasonography detected more additional suspicious lesions than DBT (P<0.0001). Twelve (44.4%) of the 27 lesions were malignant. The sensitivity and negative predictive value of US (100.0% and 100.0%) were significantly higher than those of DBT (16.7% and 83.6%, P < 0.001 and P = 0.001). The specificity of DBT was significantly higher (98.1%) than that of US (78.9%, P = 0.002). Positive predictive values of DBT and US were not significantly different (66.7% vs 52.2%, P = 0.598). The area under the receiver operating characteristic curve of US was significantly higher (0.894) than that of DBT (0.574, P < 0.001). Conclusions: Second-look US showed higher performances than DBT for detecting and characterizing suspicious lesions additionally detected on MRI in patients referred for breast cancer.