[Usefulness of quantification and visual analysis of the uptake of (99m)Tc-MIBI in the diagnosis of mammary lesions].

Objective: Scintigraphy studies with (99m)Tc-MIBI are widely used in the diagnosis of non-invasive breast cancer and their results have been verified by many studies. However, the scintigraphic technique produces erroneous false negative and positive results. This study aims to verify how the different characteristics of the uptake of (99m)Tc-MIBI (intensity, size, morphology, etc.) can help to increase sensitivity and specificity of breast scintigraphy.

Materials And Methods: We have studied 201 patients (84 breast cancer and 117 benign lesions). All of them underwent a breast scintigraphy with (99m)Tc-MIBI and anatomopathological study. A semiquantitative analysis (by T/F indexes) and visual study were performed in the lesions that presented radiodrug uptake.

Results: Eleven false positive results and 8 false negative results were obtained in the study of the 201 patients. The analysis of the T/F indexes did not demonstrate any significant differences between the benign and malignant lesions (p>0,05). There is a statistically significant correlation (p<0.05) between the tracer uptake morphology and the AP diagnosis and between the localization of the lesion in a breast quadrant and the uptake intensity.

Conclusions: Quantification of (99m)Tc-MIBI uptake by T/F indexes does not provide any conclusive data on the lesion's malignancy, however, a more detailed analysis of the characteristics of the tracer uptake would permit us to make the correct diagnosis and would reduce the false positive and negative results of this technique.