99mTc-methionine scintimammography in the evaluation of breast cancer.

OBJECTIVE: The diagnostic utility of a C-methionine scan has been established in breast cancer. We were able to radiolabel methionine with Tc at our institute. Thus, we undertook clinical trials to determine the role of Tc-methionine scans in the detection of breast cancer. METHODS: Scintimammography was performed in 47 female (median age 44 years, range 28-68 years) patients having palpable breast masses. All of them underwent ultrasound, mammography, fine-needle aspiration cytology, and Tc-methionine scintimammography before surgery. The final diagnosis was made after histopathological examination. Tc-methionine scintimammography was done after injecting 555 MBq of radiotracer intravenously. The results of scintimammography were compared with histopathology. RESULTS: The histopathological findings were malignant in 33 (70%) and benign in 14 (30%) cases. Scintimammography showed true-positive findings in 29 patients out of 33 cases of breast cancer. True-negative findings were found in 13 out of 14 patients having benign breast lesions. The sensitivity, specificity, and positive predictive value were found to be 87.8, 92.8, and 96.6% respectively. CONCLUSION: Tc-methionine imaging can provide useful information with reasonably high sensitivity and specificity in evaluating patients having breast masses.