COMPARISON OF TECHNETIUM-99M-SESTAMIBI SCINTIMAMMOGRAPHY WITH CONTRAST-ENHANCED MRI FOR DIAGNOSIS OF BREAST-LESIONS

Scintimammography using Tc-99m-sestamibi and contrast-enhanced MRI wer e performed to determine the diagnostic accuracy of either method in t he diagnostic workup of patients suspicious for breast tumors. Methods : Fifty-six patients (42 with indeterminate mammograms) underwent preo perative prone planar scintimammography and pre- and postcontrast-enha nced MRI. Visually determined signal increase after application of Gd- DTPA was compared with visually scored sestamibi uptake, and the diagn oses of both methods were correlated with the final histopathologic re sults. Results: Overall sensitivity and specificity of scintimammograp hy for diagnosing breast cancer were 88% and 83%, respectively. In the subgroup of patients with indeterminate mammograms, sensitivity was 7 9% and specificity was 83%. MRI readings provided a higher sensitivity (91% with respect to all patients and 89% with respect to patients wi th indeterminate mammograms), but a considerably lower specificity (52 % in both groups) due to contrast-enhancement in different benign lesi ons. Conclusion: Due to its considerably higher specificity, scintimam mography rather than MRI may be suitable to reduce the number of breas t biopsies which yield benign results, Thus, this method may be sugges ted as the preferable tool in the diagnostic workup of patients with i ndeterminate mammographic findings.