Prediction Model Of Recurrent Laryngeal Nerve Lymph Node Metastasis In Thoracic Esophageal Squamous Cell Carcinoma Based On Preoperative CT Examination

ObjectiveTo investigate the risk factors of bilateral recurrent laryngeal nerve lymph node metastasis in thoracic esophageal squamous cell carcinoma and to establish a model for predicting bilateral recurrent laryngeal nerve lymph node metastasis based on preoperative CT examination.MethodsThe clinicopathological data of 406 patients with thoracic esophageal squamous cell carcinoma in the Department of Thoracic surgery of the first affiliated Hospital of Zhengzhou University from August 2016 to November 2020 were analyzed retrospectively.The length and short diameter of soft tissue in the lymph node drainage area adjacent to the recurrent laryngeal nerve were measured(based on the largest soft tissue area).SPSS 23.0 and R Studio 3.4 software were used for statistical analysis,and the difference was statistically significant.The cut-off value of long and short diameter of lymph node was obtained by ROC curve,and the measured data of long and short diameter of lymph node were divided into two groups according to cut-off value.The counting data are expressed by frequency,and the measurement data are expressed by mean ±standard deviation.Chi-square test or t-test was used in univariate analysis,and the variables with statistically significant differences and clinically significant variables in univariate analysis were included in multivariate Logistic regression analysis.Furthermore,the prediction model of bilateral recurrent laryngeal nerve lymph node metastasis was established based on independent risk factors,and the correction curve and decision curve were drawn at the same time.The discrimination ability of the model was measured by c-index.ResultsA total of 369 cases of left recurrent laryngeal nerve lymph node diameter data were obtained,including 41 patients with lymph node metastasis confirmed by pathology,with a metastasis rate of 11.11%.A total of 1303 left recurrent laryngeal nerve lymph nodes were dissected,of which 64 were metastatic lymph nodes and the degree of metastasis was 4.91%.Data of 385 cases of right recurrent laryngeal nerve lymph nodes were obtained,including 66 cases of lymph node metastasis confirmed by pathology,with a metastasis rate of 17.14%.A total of 1219 right recurrent laryngeal nerve lymph nodes were dissected,of which 106 were metastatic lymph nodes,with a metastatic degree of 8.70%.There were 37 and 21 patients without soft tissue shadow in the lymph node drainage area adjacent to the left and right recurrent laryngeal nerve,respectively,and no lymph node metastasis was confirmed after operation.The cut-off values of the length and short diameter of the lymph nodes adjacent to the left and right recurrent laryngeal nerve were obtained by ROC curve as 10.4mm,7.6mm/8.1mm and 6.4mm,respectively.10mm,8mm/8mm and 6mm were used as the cut-off values of lymph node metastasis to the left and right recurrent laryngeal nerve.Univariate analysis showed that patients’ age(OR=1.059,95%CI=1.013-1.107),tumor segment(OR=2.459,95%CI=1.104-5.642),lymph node length>10.0mm(OR=4.802,95%CI=2.424-9.513,P<0.001),short diameter>8.0mm(OR=7.651,95%CI=3.564-16.422).P<0.001)is a risk factor for lymph node metastasis of left recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma.Tumor segment(OR=3,122a 95%CI of the upper segment is 1.394-6.994).The middle OR=1.966,95%CI was 1.084-3.564,the diameter of CT tumor was 1.013-1.122,the diameter of lymph node was 0.014,the long diameter of lymph node was>8.0mm(OR=5.973,95%CI was 3.231-10.911,P<0.001),and the short diameter was>6.0mm(OR=4.667,95%CI was 2.669-8.160).P<0.001)was a risk factor for right recurrent laryngeal nerve lymph node metastasis in thoracic esophageal squamous cell carcinoma.Binary multivariate Logistic regression analysis showed that the age of the patient(OR=1.064,95%CI was 1.011-1.118 and the tumor segment was.040-5.073 and the tumor diameter was 0.040);CT and 1.003-1.154 respectively),and the tumor segment was 1.040-5.073 and the tumor diameter was 1.003-1.154 and 0.041 respectively.Lymph node short diameter>8.0mm(OR=4.254,95%CI is 1.423-12.719)is an independent risk factor for lymph node metastasis of left recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma.The tumor was segmented(the upper OR=2.618,95%CI was 1.069-6.409,and the middle’OR=2.136,95%CI was 1.118-4.083,0.022).The length and diameter of the lymph nodes were>8.0mm(OR=3.620,95%CI 1.718-7.628).Lymph node short diameter>6.0mm(OR=2.106,95%CI=1.035-4.285)was a risk factor for right recurrent laryngeal nerve lymph node metastasis in thoracic esophageal squamous cell carcinoma(all P<0.05).Based on the age,tumor segment,CT tumor diameter and the diameter of lymph nodes adjacent to the recurrent laryngeal nerve,the nomogram models of lymph node metastasis of the left and right recurrent laryngeal nerve were established.The c-index of the model was 0.7609 and 0.7602 respectively.Conclusions1.Age,tumor segment,CT tumor diameter,short diameter>8.0mm are independent risk factors for lymph node metastasis of left recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma;2.Tumor segment,CT tumor diameter,long diameter of lymph node>8.0mm,short diameter>6.0mm are independent risk factors for lymph node metastasis of right recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma;3.In this study,based on the preoperative imaging evaluation of recurrent laryngeal nerve lymph node drainage area in patients with thoracic esophageal squamous cell carcinoma,a model was established to predict the metastasis of left and right recurrent laryngeal nerve lymph nodes in order to provide reference for the formulation of treatment plan,the selection of surgical approach and the plan of intraoperative lymph node dissection.