Diagnostic Accuracy of Quantitative Scintimammography Using Tc-99m MIBI According to ROC Curve Analysis for Breast Cancer

ABSTRACT

BACKGROUND: Technetium-99m sestamibi scintimammography (SMM) has been shown to be a useful diagnostic test in the detection of breast cancer, and the receiver operating characteristic (ROC) curve analysis provides detailed information about the diagnostic test. A ROC curve analysis was performed to evaluate the feasibility of Tc-99m sestamibi quantitative scintimammography (qSMM) for differentiating malignant from benign breast lesions. METHODS: Prone anterior, lateral planar, and supine SPECT imagings were performed on 75 female patients (mean age=43.4 yr) with breast masses (size> or =0.8 cm) after intravenous injection of 30 mCi of Tc-99m sestamibi. 45 malignant and 30 benign lesions were histologically proven. Three regions of interest (ROIs) were drawn over designated areas lesion (L), normal breast opposite to the lesion (NL), and right chest wall (CW). L/NL and the L/CW ratios on both the SPECT and the planar images were analyzed. RESULTS: ROC curve analysis revealed that planar L/NL ratio and the SPECT L/NL and L/CW ratios provide better diagnostic accuracies for detecting breast cancer than the planar L/CW ratio did (p<0.05). From the qSMM (mean), which was an arithmetic mean of the planar L/NL, ratio the SPECT L/NL ratio and the SPECT L/CW ratio, the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy were 84%, 77%, 84%, 77%, and 81%, respectively. Presence of axillary lymph-node metastasis showed a higher qSMM (mean) value (4.09 {n=17} vs 3.09 {n=28}, p=0.06). CONCLUSIONS: qSMM (mean) is a useful objective method for differentiating malignant from benign breast lesions.