The Application Of^99mTc-3PRGD₂SPECT/CT Imaing In The Patients Of Breast Cancer

Objective: To investigate the clinical value of^99mTc-3PRGD₂SPECT/CTimaging in the differential diagnosis of benign and malignant breast lesions.Method:312female patients who were scheduled for breast surgery or breasttissue biopsy between October2011and October2012in China-Japan Union Hospitalof Jilin University,age range19-73years,mean age42.3±12.1years,weight range42-80kg,average weight58.8±13.6kg.All patients did not receive any treatment beforethe examination, or other radionuclide examination within3months. Permission touse a new radiopharmaceutical was obtained from the local independent EthicsCommittees and the Institutional Review Boards of China-Japan Union Hospital.Written informed consent was obtained from all subjects.Patients received a bolusintravenous injection of^99mTc-3PRGD₂with a dose of11.1MBq/kg（466.2-888MBq）.The SPECT anteroposterior and lateral planar imaging and SPECT/CT tomography ofbreast and axillary lymph nodes were acquired1h later. The “gold standard” wasbased on the histopathological diagnosis.Scintigraphic images were analysed usingqualitative and semi-quantitative method respectively, then the sensitivity, specificity,accuracy, positive predictive value and negative predictive value of the diagnose werecalculated. The data were analyzed by t-test and chi-square analysis using SPSS13.0statistical software,P<0.05was considered statistically significant.Results: Among the312patients with a total of420breast lesions,108malignantlesions were confirmed by pathological examination,80were diagnosed withinvasive ductal carcinoma,14with ductal carcinoma in situ, invasive lobularcarcinoma, invasive cribriform carcinoma, mucinous carcinoma, tubular carcinoma,medullary carcinoma, malignant phyllodes tumor of two and a malignant lymphoma;Among the312benign lesions,140were diagnosed with breast adenosis,119withfibroadenoma,20with mastitis,23with milk with intraductal papilloma,8with cysts. s,The visual score≥2was adopted as positive standard by qualitative analysis,then thesensitivity, specificity,accuracy,positive predictive value and negative predictive valueof the diagnosis by^99mTc-3PRGD₂SPECT planar imaging were74.07%（80/108）,80.77%（252/312）,79.05%（332/420）,57.14%（80/140）,90.00%（252/280）, respectively,and SPECT/CT tomography were77.77%（84/108）,89.10%（278/312）,86.19% （362/420）,71.19%（84/118）,92.05%（278/302）,respectively.The differences betweenspecificity,accuracy and positive predictive value were statistically significant inpairwise comparisons（P<0.05）.When using semi-quantitative analysis, the mean T/Nratio calculated in malignant lesions on^99mTc-3PRGD₂SPECT planar imaging washigher than that obtained in benign lesions （1.76±0.43vs1.23±0.33）, with statisticalsignificance（t=13.25,P<0.05）. The mean T/N ratio calculated in malignant lesions onSPECT/CT tomography was higher than that obtained in benign lesions （3.98±1.78vs1.36±0.47）,with statistical significance（t=23.76,P<0.05）.The T/N ratio of1.2,1.4and1.6was adoped respectively as positive standard for^99mTc-3PRGD₂SPECTplanar imaging,when T/N ratio of1.5,2.0,2.5and3.0for SPECT/CT tomography.The diagnostic threshold for SPECT planar imaging was1.4based on Youden index（sensitivity+specificity-1）, by this time,the diagnostic sensitivity, specificity, accuracy,positive predictive value and negative predictive value were72.22%（78/108）,83.33%（260/312）,80.48%（338/420）,60.00%（78/130）,89.66%（260/290）,respectively.The diagnostic threshold for SPECT/CT tomography was2.5, the diagnosticsensitivity, specificity, accuracy, positive predictive value and negative predictivevalueswere75.93%（82/108）,92.31%（288/312）,88.10%（370/420）,77.36%（82/106）,91.72%（288/314）,respectively.The differences between specificity,accuracy andpositive predictive value were statistically significant in pairwise comparisons（P<0.05）.Conclusion:1.This study was the first one in our country to investigate theapplication of^99mTc-3PRGD₂SPECT/CT imaging in the patients of breast cancerbased on a large sample.2.This study demonstrated for the first time that in^99mTc-3PRGD₂SPECT planar imaging,the best diagnostic threshold forsemi-quantitative analysis was1.4, and2.5for SPECT/CT tomography imaging.3.The diagnostic performance of^99mTc-3PRGD₂SPECT/CT tomography imagingwas better than SPECT planar imaging. The diagnostic performances of^99mTc-3PRGD₂imaging using qualitative and semi-quantitative analysis were similar.4.The application of^99mTc-3PRGD₂SPECT/CT imaging in the patients of breastcancer, especially with metastasis was valuable to a certain extent.