Clinical study on lymphatic metastasis of lung cancer by intraoperative ultrasonography

OBJECTIVE: To evaluate the capacity of intraoperative ultrasonography (IUS) for lung cancer surgery in detecting the lymph nodes in mediastinum and hilum. The accuracy of IUS in determining lymph nodes metastasis was also appraised. METHODS: The lymph nodes were detected in every regions of mediastinum and hilum by IUS in 43 cases of lung cancer surgery, and the number, size and location of the lymph nodes were recorded, and the metastasis of lymph nodes were predicted by the characters of sonogram and the geometric measures respectively. The mediastinum exploration and lymph nodes resection were performed in each case, and every resected lymph node was taken a pathological examination. RESULTS: The sensitivity of IUS in detecting lymph nodes in mediastinum and hilum was 85.6%(208/243)and the positive predictive value was 95.8%(208/217). The sensitivity of IUS in detecting lymph nodes was influenced by their location and size, and the sensitivities were higher in regions of 2R, 4R and 5, and the sensitivity was the highest in the group that the diameters of the lymph nodes were more than 20 mm. The sensitivity, specificity and accuracy of IUS in diagnosing lymph nodes metastasis by the geometric measures were 88.7%(95/107),52.4%(53/101) and 71.2%(148/208), respectively, and by the characters of sonogram those were 84.2%(32/38), 55.6%(10/18) and 75%(42/56), respectively. CONCLUSION: IUS is an effective method for lung cancer surgery in detecting the mediastinum lymph nodes.