The Value Of Combined Detection Of CT And CtDNA In The Diagnosis Of Early Lung Cancer

Part Ⅰ Retrospective study in the diagnosis of lung cancer based on Lung RADSObjective:Exploring the value of Lung Imaging Reporting and Data System(Lung RADS)in the diagnosis of lung cancer.Materials and Methods:A total of 290 patients were recruited from January 2018 to January 2018,335 nodules.All patients with pulmonary nodule surgery were enrolled,and patients with known metastases were excluded.There were 123 males and 167 females.The age range is 19-87 years old,with an average age of 55.2 years and a median age of 56 years.According to the pathology,247 malignant nodules,including 29 cases of adenocarcinoma in situ(AIS),88 cases of minimally invasive adenocarcinoma(MIA),and invasive adenocarcinoma(invasive adenocarcinoma,IAC)130 cases,5 cases of lymph node metastasis were found.88 benign nodules,88 benign nodules,including 9 atypical adenomatoid hyperplasia(AAH),12 hyperplastic lymph nodes,4 organizing pneumonia,8 tuberculosis,9 hamartomas,43 chronic inflammation,1 sclerosing hemangioma,2 cryptococcal granuloma.Reclassification of enrolled lung nodules was performed by two different age physicians according to the Lung RADS criteria and evaluated for value in the diagnosis of Lung RADS system lung adenocarcinoma.Results:According to the Lung RADS,2 nodules were included in the 1 category and proved to be tuberculosis;there were 141 types of nodules,including 92 lung cancers and 49 benign nodules.The prevalence of lung cancer was 65.2%.There are 26 nodules in 3 categories,including 51 lung cancers and 9 benign nodules,the prevalence of lung cancer was 78.4%.There were 141 nodules in 4 categories,115 lung cancers,26 benign nodules,and the prevalence of lung cancer was 81.6%.2.The identification of ground glass nodules is difficult in 2 categories.3.AAH and GGN with lower pathological grade only have difficulty in distinguishing by nodule size,however,it has certain significance for AAH and GGN with higher pathological level.Conclusion:In summary,the diagnosis of lung cancer based on Lung-RADS provides a unified standard for radiologists and has a certain value in the classification of pulmonary nodules.However,due to the high diagnostic misdiagnosis rate,especially in the diagnosis of ground glass nodules,Lung RADS can not be used as a tool for lung cancer diagnosis,and may require other updated and more sensitive diagnostic methods.Part Ⅱ The value of ctDNA detection in the diagnosis of early stage lung cancerObjective:To investigate the significance of Circulating tumor DNA(ctDNA)detection in the diagnosis of early lung cancer.Materials and Methods:1.From November 2017 to August 2018,57 patients with pulmonary nodules enrolled.Exclusion:Patients who were still on medical follow-up(27 cases);Patients undergoing any invasive examination or treatment prior to surgery;Patients with other history of malignant disease(1 case);Surgical pathology indicated T2b/N1(1 case).A total of 28 patients were included in the study,including 13 males and 15 females,aged 32-77 years,with an average age of 52 years and a median age of 51 years.Of these,23 were reviewed 3 months after surgery.The highest pathological grade was recorded if the patient with multiple pulmonary nodules.Peripheral blood was taken within two weeks before surgery and three months after surgery.The sensitivity,specificity,and positive predictive value(PPV)and negative predictive value(NPV)of ctDNA detection in early lung cancer were calculated.2.Retrospective lung RADS grading was performed to analyze the prevalence of lung cancer in each category of nodules.3.Evaluate the accuracy of the combination of the two methods in the diagnosis of early lung cancer.All patients enrolled in this study signed written informed consent and approved the purpose of the study using plasma samples before and after surgical removal of tumor tissue.All samples and medical data used in this study were anonymous.Results:1.The overall positive rate of ctDNA detection was 45.8%(11/24)in 24 patients with early stage lung cancer.The ctDNA mutation rate in AIS was 25.0%(1/4),and the ctDNA mutation rate in MIA was 46.7%(7/15).The ctDNA mutation rate in I AC was 60.0%(3/5).2.21 patients with early stage lung cancer were reviewed three months after surgery,and 52.4%(11/21)of them were negative after surgery;Nine patients with negative ctDNA gene mutations before and after surgery accounted for 42.8%(9/21);Gene mutations were turned into positive after surgery,accounting for 4.8%(1/21).3.There were 20 cases of type 2 nodules,16 of which were early stage lung cancer,the diagnostic coincidence rate was only 20.0%(4/20);but 8 cases were positive for gene mutation,and the accuracy of ctDNA diagnosis of early stage lung cancer was 40.0%(8/20).There were 8 cases of 3-4 type nodules,all of which were early lung cancer,the diagnostic coincidence rate was 100%.4.The sensitivity of mutations in plasma ctDNA for the detection of early-stage lung cancer was 45.8%(95%CI,21.2%-66.8%),specificity was 100%(95%CI,39.6%-100%),PPV was 100%(95%CI,67.9%-100%),NPV was 23.5%(95%CI,7.8%-50.2%),accuracy was 53.6%;The sensitivity of Lung RADS in the diagnosis of early lung cancer was 33.3%(95%CI,16.4%-55.3%),specificity was 100%(95%CI,39.6%-100%),PPV was 100%(95%CI,59.8%-100%),NPV was 20.0%(95%CI,6.6%-44.3%),accuracy was 42.9%;The sensitivity,specificity,PPV and NPV of combined ctDNA and Lung RADS in the diagnosis of early lung cancer were 66.7%(95%CI,44.7%-83.6%),100%(95%CI,39.6%-100%),100%(95%CI,75.9%-100%),33.3%(95%CI,11.3%-64.6%),71.4%.Conclusion:The rate of misdiagnosis of early lung cancer is reduced by ctDNA,especially improved the accuracy of diagnosis early of lung cancer,and is of great significance for the diagnosis of early NSCLC.