Diagnostic Value Of ^99mTc-3PRGD₂ SPECT/CT Imaging For Oral Malignancy And Neck Lymph Node Metastasis

Objective:To investigate the diagnostic value of ^99mTc-3PRGD₂SPECT/CT imaging in oral malignancy and cervical lymph node metastasis,and compared with ¹⁸F-FDG PET/CT imaging;to evaluate the correlation between the uptake of ^99mTc-3PRGD₂and ¹⁸F-FDG,integrinαvβ3 expression level and Ki67 index in oral malignant umor.Methods:22 patients with clinically suspected oral malignancy were enrolled in this study.Anteroposterior planar imaging and tomography of head and neck were performed with ^99mTc-3PRGD₂SPECT/CT,and whole-body imaging of ¹⁸F-FDG PET/CT were performed as well during the same period（1 week）.^99mTc-3PRGD₂and¹⁸F-FDG imaging SUVmax values of primary oral lesions and cervical lymph nodes were measured respectively,and quantitative analysis was used to evaluate the uptake of imaging agents for the above lesions.The status of cervical lymph node metastasis was analyzed by visual semi-quantitative analysis.The diagnostic criteria was surgical pathology.The diagnostic value of ^99mTc-3PRGD₂ imaging and ¹⁸F-FDG imaging of oral malignancy and cervical lymph node metastasis was compared.The Ki67 index and the integrinαvβ3 in the primary oral cavity were detected by IHC after the operation,and the correlation between the uptake of （99m）Tc-3PRGD₂ and ¹⁸F-FDG SUVmax and the expression level of integrinαvβ3and the Ki67 index in the oral malignant tumor was investigated.The data were analyzed by Pearman correlation analysis,Spearman correlation analysis,χ²test,independent sample t test,paired samples t test,Z test and ROC curve analysis using SPSS 23.0 and medcalc19.1 statistical software.P<0.05 was considered statistically significant.Results:1.There were 23 oral lesions in 22 patients,all of which were malignant. ervical lymph node metastases were detected in 9 of the 19 patients undergoing surgical treatment,i.e.metastatic lymph nodes were found in 19 neck regions（45in total）,and benign enlargement of lymph nodes was observed in 77 regions（776in total）.2.The ^99mTc-3PRGD₂ and ¹⁸F-FDG SUVmax values of the primary oral cavity were 5.94±1.71 and 15.18±5.87.There was not significant positive linear relation-ship between them（r=0.193,P>0.05）.The difference between the two was statisti-cally significant（t=7.652,P<0.01）.3.The expression intensity of oral primary integrinαvβ3 was correlated with Ki67 index（r=0.702,P<0.01）.The ^99mTc-3PRGD₂ SUVmax value was correlated with the expression of integrinαvβ3（r=0.578,P<0.05）.There was no significant positive linear correlation between the SUVmax value of ¹⁸F-FDG and Ki67 index（r=0.233,P>0.05）.4.Visual analysis:based on cervical lymph node region,the sensitivity,speci-ficity,accuracy,positive predictive value and negative predictive value of ^99mTc-3PRGD₂ imaging and ¹⁸F-FDG imaging were 89.47%,81.82%,82.29%,51.61%,96.92%and 89.47%,87.01%,87.50%,62.96%,97.10%,respectively,with no tatistical significance（χ² were 0,0.790,0.669,0.393,0.004 respectively,P>0.05）.The above diagnostic indexes of the two imagings were 62.22%,96.39%,95.42%,50%,97.78%and 68.89%,97.68%,96.10%,63.27%,98.19%,respectively,based on the judgment of lymph node lesions.The differences were not statistically ignificant（χ² were 0.443,2.240,2.303,1.868,0.325 respectively,P>0.05）.5.The SUVmax values of ^99mTc-3PRGD₂ and ¹⁸F-FDG in cervical metastatic lymph nodes were higher than those of negative lymph nodes（2.62±1.25 vs.1.45±0.65,t=5.1,P<0.01;6.05±4.96 vs.1.56±0.77,t=5.1,P<0.01）.There was a positive linear correlation between the SUVmax values of ^99mTc-3PRGD₂ and ¹⁸F-FDG for the cervical lymph node（r=0.483,P<0.01）.6.When the ^99mTc-3PRGD₂SUVmax value was 2.32,it can be used as the best cut-off value to judge the cervical lymph node metastasis,and the AUC was0.825.The cut-off value of ¹⁸F-FDG SUVmax was 2.85,and the AUC was 0.855.According to the best cut-off value,the sensitivity,specificity and accuracy of the two imagings diagnoses were 71.9%,93.9%,88.46%and 78.1%,93.9%and 90.0%,respectively,with no statistical significance（χ² were 0.333,0,0.160 respectively,P>0.05）.There was no significant difference between the two imagings in the diagnosis of cervical metastatic lymph nodes（Z=0.549,P>0.05）.Conclusion:1.Both ^99mTc-3PRGD₂ SPECT/CT and ¹⁸F-FDG PET/CT detected all primary oral lesions.However,the radioactive uptake of the latter lesion was significantly higher than that of the former.^99mTc-3PRGD₂ SUVmax value of primary oral avity was correlated with the expression intensity of integrinαvβ3.Moreover,the expression intensity of integrinαvβ3 was correlated with the Ki67 index.There as no significant positive correlation between ^99mTc-3PRGD₂ SUVmax value and Ki67 index.2.There was no significant difference between ^99mTc-3PRGD₂ imaging and¹⁸F-FDG imaging in the diagnosis of cervical metastatic lymph nodes of oral alignancy,but the latter had a higher target/background ratio.^99mTc-3PRGD₂SPECT/CT imaging had good efficacy in the diagnosis of oral malignancy and cervical lymph node metastasis.