Correlation Between ¹⁸F-FDG PET/CT Imaging And EGFR Gene Mutation And The Prognostic Value Of The Metabolic Parameters In Patients With Lung Adenocarcinoma

Objective:To evaluate the correlation between ¹⁸F-FDG PET/CT features and epidermal growth factor receptor?EGFR?mutation and to investigate the prognostic value of metabolic parameters on baseline ¹⁸F-FDG PET/CT in patients with lung adenocarcinomas.Methods:We reviewed 169 patients with lung adenocarcinomas who underwent baseline ¹⁸F-FDG PET/CT scan in Qingdao Affiliated Hospital from January 2015 to October 2017 retrospectively.The EGFR gene mutation status was tested by the ARMS method.The clinical information?such as sex,age,smoking history,tumor TNM staging?,CT features?long diameter of the primary tumor,short diameter of the primary tumor,CT value,the ratio of the CT value of the tumor to the normal lung tissue,lobulated shape,spicules of margin,cavity,air containing space and vacuole,Sign of air bronchus,truncation sign,calcification,liquefaction,vascular convergence sign,pleural indentation sign?and metabolic parameters?such as SUVtumor,SUVLN,SUVtumor/lung,SUVLN/lung,SUVtumor/liver,SUVLN/liver,MTV,TLG?were assessed for predicting the EGFR status and Progression-free survival.The relationship between imagine features and EGFR status were analyzed by t-test or the Mann–Whitney U test.The statistic analyses of multi-sample were compared by chi-square test.The logistic regression analyses were performed on the factors which were statistical significance.ROC curves were plotted to estimate the optimal cut-off values and diagnostic efficacy of each parameter.The Univariate survival analysis was performed by Kaplan-Meier method with Log-rank test.Results:1.One hundred and ninety-six patients with lung adenocarcinomas were enrolled in this study including 93 cases of men and 103 cases of women which contain 121 patients with EGFR gene mutation and 75 cases of wild type.The mean age was 61.5±8.3 year.Seventy-four patients were followed up in this study.The follow-up time was 10.6±4.35 months.By the deadline of follow-up,6 patients died and 68 survived,including 34 recurrences.2.The correlation between PET/CT image characteristics and EGFR gene mutations in patients with lung adenocarcinoma was analyzed.The patient's gender,pleural indentation sign,SUV_tumor,SUV_tumor/lung,SUV_tumor/liver,SUV_LN/SUVtumor,MTV,TLG were significant differences between the EGFR mutation group and the wild type group.Logistic regression showed that only the pleural indentation sign was an independent risk factor for predicting EGFR gene mutation.3.The univariate analysis of solid-density lung adenocarcinoma showed that the smoking history,spicules of margin,pleural indentation sign,SUV_tumor,SUV_tumor/lung,SUV_LN/tumor,MTV,TLG were significant differences in EGFR mutation group and wild type group.Logistic regression analysis showed that only pleural indentation sign was an independent risk factor for predicting EGFR gene mutations in solid-density lung adenocarcinoma.In mixed-density lung adenocarcinoma,the results of univariate analysis showed that gender,smoking history,vascular convergence sign,pleural indentation sign were significantly different between the two groups,and the metabolic parameters were not different between the two groups.The Logistic regression results showed that pleural indentation sign was an independent risk factor for predicting of mixed-density lung adenocarcinoma EGFR gene mutations.4.The univariate analysis showed that gender,smoking history,cavity,pleural indentation sign and SUV_tumor/lung were significantly different between EGFR mutations and wild-type groups in I-II stage lung adenocarcinoma patients.The Logistic regression analysis showed that pleural indentation sign is an independent risk factor for predicting EGFR gene mutation in patients with stage I-II lung adenocarcinoma;Univariate analysis showed that SUV_LN/Lung,lobulated shape,spicules of margin,vascular convergence sign and pleural indentation sign were statistically significant in in wild and mutant groups in patients with stage III-IV lung adenocarcinoma,Logistic regression analysis showed that spicules of margin was an independent risk factor for predicting EGFR gene mutation in patients with stage III-IV lung adenocarcinoma.5.The SUV_tumor and SUV_LN could effectively predict the progression-free survival in patients with stage II to IV lung adenocarcinoma??²=6.392,9.118;P=0.011,0.003?.The ROC curves showed that the SUV_LN had the best performance in predicting PFS?AUC:0.750,95%CI:0.577-0.925?.Conclusion:pleural indentation sign could predict EGFR gene mutation status,¹⁸F-FDG PET/CT metabolic parameters could not effectively predict the lung adenocarcinoma gene mutation status.SUV_tumorumor and SUV_LN have good prognostic value to predict the PFS in patients II to IV lung adenocarcinoma.