Technetium-99m-Tetrofosmin Scintimammography in Suspected Breast Cancer Patients: A Comparison with Technetium-99m-MIBI
Objective: To investigate the diagnostic role of 99mTc-tetrofosmin in the detection of primary breast cancer and axillary lymph node metastasis and to compare the findings with those of 99mTc-MIBI. Methods: Forty-eight patients with clinically palpable masses or abnormal radiologic findings had 99mTc-MIBI and 99mTc-tetrofosmin scintimammographies (SMMs) after intravenous injections of 925 MBq of radiopharmaceuticals. The SMMs were correlated with histopathologic findings. Results: Thirty-three patients were diagnosed with breast cancer and 15 patients with benign breast diseases. The number of true positive, true negative, false positive, and false negative cases of 99mTc-tetrofosmin SMM were 31, 10, 5, and 2, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of 99mTc-tetrofosmin SMM were 93.9, 66.7, 86.1 and 73.3%, respectively. The number of true positive, true negative, false positive, and false negative cases of 99mTc-MIBI SMM was 29, 10, 5, and 4, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of 99mTc-MIBI SMM were 87.8, 66.7, 85.3 and 73.3%, respectively. In assessment of axillary lymph node involvement, 99mTc tetrofosmin SMM demonstrated 31.8, 100, 100, and 42.3% sensitivity, specificity, positive and negative predictive values, respectively. The sensitivity and specificity of 99mTc-MIBI SMM was 22.7 and 100%. Positive and negative predictive values were 100 and 39.3%, respectively. One patient was false negative in both 99mTc-MIBI and 99mTc-tetrofosmin SMMs with a tumor size of 0.5 cm. Conclusion:99mTc-tetrofosmin and 99mTc-MIBI SMMs were noninvasive and useful in the detection of primary breast cancer and 99mTc tetrofosmin was comparable to 99mTc-MIBI in the detection of primary breast cancer. However, both radiopharmaceuticals had limited values in the assessment of axillary lymph node involvement.