Background: Mammography has a positive predictive value in the detection of breast cancer of 15% to 25%. Ten percent of patients with breast cancer present with normal mammograms; however, the false negative rate is increased in younger patients. The purpose of this study was to evaluate the effectiveness of Tc-99m Sestamibi imaging in the diagnosis of breast disease.
Methods: Images were collected on 147 women. Patients were evaluated with a combination of physical examination, sonography, and mammography. Each patient received 20 millicuries of Tc-99m Sestamibi intravenously. Anterior and lateral images were obtained, the latter with the patient prone and the breast in the dependent position.
Results: One hundred seven patients showed no enhancement (negative scan). Seven of these patients were found at biopsy to have carcinoma. Five had ductal carcinoma in-situ (DCIS) with no associated mass, 1 had an incidental 3 mm focus of invasive ductal carcinoma (IDC), and 1 had a 5-cm cystic lesion with IDC. Forty-one patients showed focal enhancement on their scans (positive scan). Thirty-six were found to have either invasive or in-situ cancer. Four of the 5 patients with benign findings had sclerosing adenosis. The positive and negative predictive values for scintimammography in this group of patients were 88% and 93%, respectively. The sensitivity and specificity were 84% and 95%, respectively.
Conclusions: We conclude that scintimammography is a highly specific test that deserves study as a modality to further refine the indications for breast surgery.