The Clinical Role Of ^99mTc-3PRGD₂ SPECT/CT In The Diagnosis Of Breast Cancer: A Comparison With Ultrasound

Objective:to evaluate the diagnostic value of ^99mTc-3PRGD₂ integrin receptor scintimammography in the assessment of breast lesions and compare its results with that of ultrasound.Methods:forty-four patients with suspicious breast lesions were enrolled in the study,all had performed breast ultrasound and ^99mTc-3PRGD₂ SPECT/CT successively.Planar scan and SPECT/CT were performed at dual time points of 1h and 3h after the injection of⁹9m9m Tc-3PRGD₂,and images were evaluated visually and semi-quantitatively by three experienced nuclear medicine physicians.The tumor-to-background?T/B?ratios were calculated for semi-quantitative analysis.The expression of integrin?_v?₃ of the breast tissue samples were histologically measured.Results:Malignant breast lesions were clearly distinguished from benign lesions with higher T/B ratio?2.05±0.54 vs 1.26±0.30,1h planar imaging,P<0.001;4.16±1.79 vs2.26±1.30,1h SPECT imaging,P<0.001;1.85±0.56 vs 1.21±0.23,3h planar imaging,P<0.001;3.48±1.82 vs 1.99±0.92,3h SPECT imaging,P<0.001?.No matter planar imaging or SPECT imaging,for malignant lesions,the T/B ratios of 1h imaging were higher than the 3h imaging?P<0.05?.While,there was no significant statistical difference in the benign lesions.The semi-quantitative analysis was superior to ultrasound and visual analysis in specificity?92.0%,64.0%,60.0%?and positive predictive value?PPV??88.2%,65.4%,73.9%??P<0.05,relatively?.As for sensitivity,it was 78.9%in semi-quantitative analysis of 1h planar imaging and it could reach 89.5%in visual analysis when considering the volume effect,necrosis or heterogeneity and metastases.For breast ultrasound examination,the sensitivity was 78.9%.The negative predictive value?NPV?were 85.2%,88.9%and 71.1%,relatively.While there were no significantly statistical difference in neither sensitivity nor NPV between these two diagnostic tools.Conclusion:^99mTc-3PRGD₂ integrin receptor imaging is a promising method with a high specificity and positive predictive value for breast lesions versus ultrasound.SPECT/CT may improve the sensitivity of breast cancer which is un-conclusive in ultrasound.