Mammoscintigraphy with Technetium-99m-Sestamibi in Suspected Breast Cancer

Our goal was to determine the clinical usefulness of ^99mTc-sestamibi to identify breast cancer in patients prior to biopsy. Methods: We studied 66 patients who received 20 mCi ^99mTc-sestamibi intravenously. Lateral and anterior planar images were gathered within 30 min of the injection. Only focal increased uptake was interpreted as positive. Confirmatory pathologic diagnoses were obtained within 2 mo. The prevalence of breast cancer in our sample was 54%. Results: We report an overall sensitivity of 83% and specificity of 93% for the diagnosis of breast cancer. In palpable lesions, the sensitivity was of 94% with a specificity of 91%, while in nonpalpable abnormalities the sensitivity was of 64% with a 100% specificity. Six patients with a malignancy had negative scans, four of these lesions were nonpalpable. Only two of 31 patients with benign lesions had an abnormal scan. Conclusion: Mammoscintigraphy with ^99mTc-sestamibi has high specificity and adequate sensitivity for the noninvasive diagnosis of breast carcinomas.