^99mTc-3P₄-RGD₂Scintimammography In The Assessment Of Breast Lesions: Comparative Study With^99mTc-MIBI

Purpose: To compare the potential application of99mTc-3P4-RGD2scintimammography (SMM) and99mTc-MIBI SMM for the differentiation ofmalignant from benign breast lesions.Method: Thirty-six patients with breast masses on physical examination and/orsuspicious mammography results that required surgery were included in the study.99mTc-3P4-RGD2and99mTc-MIBI SMM were performed with single photon emissioncomputed tomography (SPECT) on a separate day, two check interval is48h. Thegold standardμ was based on the histopathological diagnosis of the surgical samplesfrom all recruited patients. Images were evaluated by the tumor to non-tumorlocalization ratios (T/NT). Regions of interest (ROIs) were drawn around the tumorand an area of normal breast tissue in the same breast on lateral images and used todetermine the tumor to non-tumor ratios (T/NT) of99mTc-3P4-RGD2and99mTc-MIBI.Receiver operating characteristic (ROC) curve analysis was performed on eachradiotracer to calculate the cut-off values of quantitative indices and to compare thediagnostic performance for the ability to differentiate malignant from benign diseases.Informed consent was obtained from all subjects. Permission to use a newradiopharmaceutical was obtained from the local independent Ethics Committees andthe Institutional Review Boards of China-Japan Union Hospital. Analysis of t-test andZ-test were used with SPSS19.0software.Results: Among the36patients,39cases of lesions were founded,28(71.8%)were diagnosed as malignant and11(28.2%)were benign. The mean T/NT ratio of99mTc-3P4-RGD2in malignant lesions was significantly higher than that in benignlesions (3.54±1.51vs.1.83±0.98；t=3.47，P <0.01). The sensitivity, specificity,and accuracy of99mTc-3P4-RGD2SMM were89.3%（25/28）,90.9%（10/11）and89.7%（35/39）, respectively. The mean T/NT ratio of99mTc-MIBI in malignant lesionswas also significantly higher than that in benign lesions (2.26±0.99vs.1.51±0.61；t =2.33，P <0.05). The sensitivity, specificity and accuracy of99mTc-MIBI SMM were85.7%（24/28）,72.7%（8/11）and82.1%（32/39）, respectively. The T/NT ratio inbreast cancer of99mTc-3P4-RGD2SMM was significantly higher than that of99mTc-MIBI SMM（3.54±1.51vs.2.26±0.99；t=3.75，P<0.05）. The incrementaldiagnostic value of quantitative indices analysis was performed using calculated areasunder the curve (AUCs) in ROC analysis. Statistical significance was defined as p＜0.05.According to the ROC analysis, the area under the curve for99mTc-3P4-RGD2SMM (area=0.851) was higher than that for99mTc-MIBI SMM (area=0.781), but thestatistical difference was not significant (Z=0.60, P>0.05).Conclusion：The diagnostic efficiency of99mTc-3P4-RGD2SMM was equivalentto that of99mTc-MIBI SMM for the detection of primary breast cancer. The T/NT ratioin breast cancer of99mTc-3P4-RGD2SMM was significantly higher than that of99mTc-MIBI SMM.