Benign versus malignant breast disease: Comparison of contrast-enhanced MR imaging and Tc-99m tetrofosmin scintimammography

PURPOSE: To compare technetium-99m tetrofosmin scintimammography with contrast material-enhanced magnetic resonance (MR) imaging in the characterization of palpable breast masses. MATERIALS AND METHODS: Forty-seven patients (mean age, 51 years) with a Palpable breast mass were prospectively examined with scintimammography, MR imaging, and conventional mammography 2 weeks before fine-needle aspiration biopsy. RESULTS: In three patients, MR imaging was aborted, Of the remaining 44 patients, 21 had biopsy-proved cancer and 23 had benign disease. The sensitivity of mammography was 81%; specificity, 82%; positive predictive value (PPV), 85%; and negative predictive value (NPV), 78%. The sensitivity of scintimammography was 95%; specificity, 91%; PPV, 91%; and NPV, 95%. The sensitivity of MR imaging was 90%; specificity, 91%; PPV, 90%; and NPV, 91%. In 11 patients with previous breast cancer, scintimammographic findings were positive in all four with tumor recurrence and negative in all seven with benign disease. Masses were correctly characterized with MR imaging in eight of these 11 patients. CONCLUSION: Although both techniques accurately differentiate benign from malignant palpable breast masses, scintimmagraphy is more accurate in the posttreatment breast. Because of lower cost, wider availability, and high patient acceptance, scintimammography may provide a valuable alternative to MR imaging for noninvasive characterization of palpable breast disease.