The role of scintimammography with 99m-Tc-Tetrofosmin in breast cancer detection

Aim: It is already known that breast cancer is the most common malignancy of women. Breast mammography, although it is of a great importance as a screening test, it has some limitations, especially in women with dense breast tissue, or in those who underwent partial mastectomy and post-surgical scars are present. This resulted in the necessity of the use of other complementary imaging procedures, such as ultrasonography, magnetic resonance imaging and scintimammography with technetium-99m labeled agents (Methyl-Isobutyl-Isonitrile: MIBI) or monoclonal antibodies. In the present study the contribution of scintimammography with 99m- Tc- Tetrofosmin in the diagnosis of breast cancer and/or local relapses is investigated. Material-Methods: 91 women aged 22-72 years old with strong clinical and/or mammographic suspicion of breast cancer and/or local relapse after mastectomy (92 lesions) were investigated. All patients underwent scintimammography with 99m-Tc-Tetrofosmin (dose: 20mCi) before surgery and/or biopsy. An intravenous injection was performed at the contralateral site of that of the suspected or palpable lesion. Imaging was performed 10 minutes post-injection. Patients were at a prone position and lateral and views of the breasts and axillary areas were performed (10 minutes per view, matrix size 128x128, high resolution collimator).Anterior views of the breasts and axillary areas were performed with the patients placed in at supine position. Results: The overall Sensitivity was 85,7%, Specificity was 87,9%, Positive Predictive Value was 81,9%, Negative Predictive Value was 90,7% and Diagnostic Accuracy was 85,3%.Three out of three local relapses were detected,as well as one out of one bilateral involvement. In a case of negative breast scan and positive findings at the axillary area, histology revealed a lymphoma. Conclusions: Scintimammography with 99m-Tc-Tetrofosmin is a valuable method in the detection of primary breast cancer or the early diagnosis of local relapses. It is statistically superior from other imaging modalities that are used complementary with mammography in what it concerns Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value