The Value Of ¹⁸F-FDG Pet/CT Examination And Chest Enhanced CT In The Diagnosis Of Non-small Cell Lung Cancer And Lymph Node Metastatisis

Objective:To Evaluate the diagnostic value of ¹⁸F-FDG PET/CT and Chest Enhanced CT in Non-Small Cell Lung Cancer（NSCLC）and metastatic lymph node.Methods:Retrospectively analyzed during January 2013 to October 2020the clinical diagnosis of NSCLC 83 patients in the first affiliated hospital of Guangxi Medical University,with ¹⁸F-FDG PET/CT examination and chest CT enhancement scan before treatment,Two checks were completed in the first 3weeks.There is a result of the treatment of prodrug routine,Cytokine-19-fragments（CYFRA21-1）,Carcinoembryonicantigen（CEA）.With Lymph node metastasis or not,they are divided into two groups:Lymph node metastasis（LNM）group and No Lymph node metastasis（NLNM）group.Referring to the pathological results,two imaging examination methods were calculated on the specificity,sensitivity,negative predicted value,positive predicted value of NSCLC and its lymph node metastasis.There is no statistically significant difference in different clinical indicators and parameter groups,using independent sample t test or Mann-Whitney U test.Factors that may affect NSCLC lymph node metastasis were analyzed by single factors Logistic regression analysis and binary Logistic regression preliminary analysis,thereby obtaining independent risk factors.Using the ROC curve to analyze the outer area（AUC）of each indicator and parameters,the optimal threshold for evaluating NSCLC lymph node metastasis is obtained.P<0.05 is statistically significant.Results:（1）General data and clinical data:A total of 83 patients who were clinically diagnosed as NSCLC were included in this project.Before treatment,all underwent ¹⁸F-FDG PET/CT imaging and chest enhanced CT,and 7 cases were pathologically confirmed to be benign disease and 76 cases were confirmed to be NSCLC.Among the 76 NSCLC patients,the age range was40～77 years old,the median age was 54 years old,with 45 males and 31females.29（38.2%）had a history of smoking,47（61.8%）had no history of smoking,NLR,carcinoembryonic antigen（CEA）,cytokerantin 19 fragment（CYFRA21-1）.with pathological classification,According to the pathological classification,the patients were divided into:（1）76 NSCLC patients:lung adenocarcinoma 67 cases（88.2%）,lung squamous cell carcinoma 7 cases（9.2%）,lung adenosquamous cell carcinoma 2 cases（5.6%）;（2）All 7 cases were benign diseases.According to the postoperative pathology as the gold standard,they were divided into LNM group（n=40）and NLNM group（n=36）.According to Mann-Whitney U test,the smoking history and serum tumor markers（CYFRA21-1 and CEA）levels in the LNM group were markedly higher than those in the NLNM group（P<0.05）,while there was no marked difference between the neutral granulocyte/lymphoid ratio（NLR）group（P>0.05）.（2）Analysis of diagnostic efficacy of ¹⁸F-FDG PET/CT imaging and chest enhanced CT:The diagnosis efficiency of NSCLC primary stoves is:Sensitivity 86.8%（66/76）,84.2%（64/76）;a specific value of 57.1%（4/7）,28.6%（2/7）;positive predictive value 95.7%（66/69）,92.8%（64/69）;negative predictive value of28.6%（4/14）,14.3%（2/14）.the diagnosis of NSCLC lymph node metastasis:Sensitivity 77.5%（31/40）,52.5%（21/40）;a specific value of 86.1%（31/36）,88.8%（32/36）;positive predictive value 86.1%（31/36）,84%（21/25）;negative predictive value 77.5%（31/40）,62.7%（32/51）.Using Mc Nemar test analysis¹⁸F-FDG PET/CT and chest enhancement CT has no marked difference in accuracy of diagnosis of NSCLC original stove（P=1.000）,but the different differences in accuracy statistics on diagnosis of NSCLC lymph node metastasis（P<0.05）.（3）Comparison of primary lesion parameters between the LNM group and the NLNM group:Independent sample t test or Mann-Whitney U testwas used to analyze original lesion diameter（Dmax）,the aximum standardized uptake value of the primary focus（T-SUVmax）,tumor SUVmax to mediastinal SUVmean ratio（B-SURmax）,tumor SUVmax to liver SUVmean（L-SURmax）,Metabolic Tumor Volume（MTV）,Total Evaluation on Original Glycolysis（TLG）,CT contrast value（CT ratio）in LNM group and NLNM group.The levels of Dmax,T-SUVmax,B-SURmax,L-SURmax,MTV and TLG parameters in LNM group were obviously higher than those in NLNM group（P<0.05）.There was no marked difference between CT ratio（P>0 0.05）.（4）Influential factors of NSCLC metastatic lymph node:11 factors including smoking history,Dmax,T-SUVmax,B-SURmax,L-SURmax,MTV,TLG,CT ratio,NLR,CYFRA21-1 and CEA were included in univariate Logistic regression analysis,and the results were as follows:Dmax,B-SURmax,L-SURmax,MTV and TLG were risk factors with metastatic lymph node（P<0.05）.But NLR,CEA,CYFRA21-1,CT ratio were not risk factors for NSCLC metastatic lymph node（P>0.05）.Smoking history and T-SUVmax can be used as independent risk factors for assessing lymph node metastasis of NSCLC（P<0.05）.（5）to evaluate lymph node metastasis of NSCLC with ROC curve analysis:the AUC of Dmax,T-SUVmax,B-SURmax,L-SURmax,MTV,TLG,CYFRA21-1,CEA were respectively:0.692,0.701,0.650,0.652,0.694,0.706,0.681 and 0.676,All had statistical significance（P<0.05）;However,there was no statistical significance in AUC of NLR and CT ratio（P>0.05）.The AUC of Dmax,T-SUVmax,B-SURmax,L-SURmax,MTV,TLG,CYFRA21-1 and CEA were larger,and the optimal bound points were obtained according to Youden index as follows:3.95cm,5.71,3.15,2.915,28.725cm³,113.965g,5.645ng/ml and 5.615ng/ml.The most cutoff value of Dmax is 3.95cm（sensitivity 42.5%,specificity 86.1%）,The most cutoff value of T-SUVmax is 5.71（sensitivity87.0%,specificity50.0%）,The most cutoff value of B-SURmax is 3.15（sensitivit-y 90.0%,specificity 41.7%）,The most cutoff value of L-SURmax is 2.915（sensi-tivivity 82.5%,specificity 50.0%）,The most cutoff value of MTV is28.725m³（sensitivity 70.0%,specificity 63.9%）,The most cutoff value of TLG is 113.965g（sensitivity 77.5%,specificity 61.1%）,The most cutoff value of CYFRA21-1 is 5.645ng/ml（sensitivity 37.5%,specificity 91.7%）,The most cutoff value of CEA is 5.615ng/ml（sensitivity 57.5%,specificity 83.3%）.Conclusion:（1）The value of ¹⁸F-FDG PET/CT imaging in the overall assessment of NSCLC is superior to chest enhanced CT..（2）Smoking history and¹⁸F-FDG PET/CT semi-quantitative parameter T-SUVmax is independent risk factors for metastatic lymph node in NSCLC patients,and T-SUVmax is of great value in semi-quantitative prediction of the risk of lymph node metastasis of NSCLC.