[Application value of CT examination of lymph node short diameter in evaluating cardia-left gastric lymph node metastasis in thoracic esophageal squamous cell carcinoma].

Objective: To investigate the application value of computed tomography (CT) examination of lymph node short diameter in evaluating cardia-left gastric lymph node metastasis in thoracic esophageal squamous cell carcinoma (ESCC). Methods: A total of 477 patients with primary thoracic ESCC who underwent surgical treatment in the Affiliated Cancer Hospital of Zhengzhou University from January 2013 to December 2017 were collected. All of them underwent McKeown esophagectomy plus complete two-field or three-field lymph node dissection. Picture archiving and communication system were used to measure the largest cardia-left gastric lymph node short diameter in preoperative CT images. The postoperative pathological diagnosis results of cardia-left gastric lymph node were used as the gold standard. Receiver operating characteristic (ROC) curve was used to evaluate the efficacy of CT lymph node short diameter in detecting the metastasis of cardia-left gastric lymph node in thoracic ESCC, and determine the optimal cut-off value. Results: The median short diameter of the largest cardia-left gastric lymph node was 4.1 mm in 477 patients, and the largest cardia-left gastric lymph node short diameter was less than 3 mm in 155 cases (32.5%). Sixty-eight patients had cardia-left gastric lymph node metastases, of which 38 had paracardial node metastases and 41 had left gastric node metastases. The lymph node ratios of paracardial node and left gastric node were 4.0% (60/1 511) and 3.3% (62/1 887), respectively. ROC curve analysis showed that the area under the curve of CT lymph node short diameter for evaluating cardia-left gastric lymph node metastasis was 0.941 (95% CI: 0.904-0.977; P<0.05). The optimal cut-off value of CT examination of the cardia-left gastric lymph node short diameter was 6 mm, and the corresponding sensitivity, specificity and accuracy were 85.3%, 91.7%, and 90.8%, respectively. Conclusion: CT examination of lymph node short diameter can be a good evaluation of cardia-left gastric lymph node metastasis in thoracic ESCC, and the optimal cut-off value is 6 mm.