The Value Of ¹⁸F-FDG PET/CT For Diagnosis Of Lymphatic Metastasis In The Patients With Non-small Cell Lung Cancer

Background and purposeImaging examination is the most commonly used way to determine whether there is a lymph node metastasis in non–small-cell lung cancer（NSCL）,but the computer tomography diagnoses benign and malignant tumor and lymph node only based on morphology,CT value,and the enhancement of the situation.¹⁸F-FDG PET/CT has unparalleled advantages,It can not only judge on morphology,but also can provide the evidence of benign and malignant tumor and lesions on the molecular metabolism level.Materials and MethodsThe clinical data of 167 patients of NSCLC who was admitted to the department of thoracic surgery,Daping hospital,Third Military Medical University from Match 2012 to May 2015 were collected,which mainly include gender,age,smoking,chronic lung disease history,complained of time medical records and the examination result of PET/CT,enhanced CT and pathology.The sensitivity,specificity,accuracy,positive and negative predictive were calculated according to pathologic results.Meanwhile,the correlation between lymph node metastasis rate with the gender,sex,smoking history and chronic lung disease history were analysed.Results1.There were 167 patients have taked the ¹⁸F-FDG PET/CT and enhanced CT examination at the same time.There were 731 lymph node stationsfrom the 167 patients.Referred to the final pathological results,PET/CT has screened 143 lymph node stations in true positive set,26 lymph node stations in false positive set,61 lymph node stations in false negative set,and 501 lymph node stations in true negative set.Furthermore,the sensitivity,specificity,the positive and negative forecast values,and Youden index of PET/CT and CT was 70.10% vs.54.19%（p < 0.05）,95.07%,vs.92.23%（p < 0.05）,88.10% vs.81.67%（p < 0.05）,84.62% vs.72.85%（p < 0.05）,89.15% vs.81.67%（p < 0.05）and 0.65 vs.0.46（p < 0.05）,respectively.2.The primary tumor diameter were 4.37±1.98 cm,4.17±1.94 cm and 3.98±1.95 cm measurement by PET/CT,enhanced CT and pathology,respectively.There were no significant difference between three diameters（F=1.65,P=0.193>0.05）3.PET/CT determine the number of lymph node staging accurate and not accurate were 120 cases（71.86%）and 47（28.14%）,There were significant difference between two methods（P=0.004<0.05）.PET/CT in patients with TNM staging accuracy number,inaccurate cases respectively in 102 cases（61.08%）,65 cases（38.92%）and enhanced CT were 82 cases（49.10%）,85 cases（50.90%）,and both have significant difference（P = 0.028 < 0.05）.4.169 lymph nodes which was measured by PET/CT and enhanced CT was visible and no fusion and maximum sizes were 15.09 ± 6.87 mm and 14.84 ± 6.52 mm.therehave statistical difference（t=3.01,P < 0.05）,and the former was slightly bigger than the latter.5.The clear positive lymph nodes and negative measured by PET/CT and the pathology were 157,129,the maximum diameter were 15.07±6.76 mm,11.02±4.07 mm,respectively.There were statistical differences between the two（t=6.40,P=0.00 < 0.05）,and the former was significantly higher than the latter.6.In 286 lymph nodes of PET/CT measurement and the pathological results clearly positive lymph node was 157,negative 129.Lymph node positive and negative lymph node SUVmax were9.90±5.82,5.39±3.00,respectively.Both of the SUV,positive lymph nodes and negative lymph nodes of the SUVmax,SUVmean are statistically different（t=8.71,P=0.00 < 0.05;t=10.07,P=0.00 < 0.05）,and the former is obviously higher than the latter.Conclusion1.Compared with enhanced CT,¹⁸F-FDG PET/CT is superior in diagnosing the metastasis of lymph nodes in non-small cell lung cancer.2.There is some indexes such as the maximum diameters of lymph nodes,SUVmax,SUVmean and so on in lymph nodes which are helpful to assess the metastasis of lymph node.