INTRODUCTION: Scintimammography is a non-invasive, painless diagnostic imaging method employed in the detection of breast cancer, when X-ray mammography is inconclusive. Due to the advantages of using the 99mTc tracer and its efficiency in detecting carcinomas, sestamibi is the most commonly used agent for this purpose. Its uptake in the tumor has multifactorial causes which are independent of the presence of architectural distortions and local or diffused variations in density of the breast.
AIM: To evaluate the efficiency of scintimammography using 99mTc sestamibi in the detection of cancer.
METHODS: A total of 157 patients with 158 palpable and non-palpable mammary nodules were evaluated. Three patients were male and 154 were female with ages ranging from 14 to 81 years old. All the patients were submitted to scintimammography and the nodules to cytologic and histologic studies.
RESULTS: One hundred and eleven malignant nodules and 47 benign nodules were detected with a predominance of ductal carcinoma (n=94) and fibroadenoma and fibrocystic condition (n=11/n=11) respectively. The mean size was 3.11 cm (range 7 to 10 cm) in malignant nodules and 2.07 cm (range 0.5 to 10 cm) in benign nodules. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 89%, 89%, 95% 78% and 89% (k=0.8924; p-value < 0.001). Analysis relating to the size, histologic type, and location revealed greater efficiency in detecting larger nodules, more aggressive tumors such as ductal tumors and nodules located in external and intermediary regions.
CONCLUSIONS: In this study, scintimammography with 99mTc sestamibi proved to be a diagnostic imaging method efficacious in the detection of breast cancer. As diagnosis should be fast and precise and that false-negative mammographies delay biopsy in breast cancer sufferers, scintimammography using 99mTc sestamibi may play an important role when X-ray mammography is inconclusive.
