Preoperative diagnosis of lymph node metastasis of gastric cancer. A comparison of diagnostic imaging

We studied the usefulness of dynamic computed tomography (CT), abdominal ultrasonography (US) and endoscopic ultrasonography (EUS) for the diagnosis of lymph node metastasis of gastric cancer. Seventy eight resected cases of gastric cancer were subjected to the study. The results of diagnosis of lymph node metastasis obtained by CT in 30 cases, US in 78 cases and EUS in 44 cases were compared with the histological results. The regional lymph nodes were classified into three groups, that is, the lesser curvature group consisting of lymph nodes 1, 3 and 5, the greater curvature group consisting of lymph nodes 2, 4 and 6, and the celiac artery group consisting of lymph nodes 7, 8, 9 and 11. The sensitivity of the diagnosis by EUS for the metastasis of the lesser curvature group was 69% and the accuracy was 80%, these percentages being better than those by US and CT. The sensitivity of the diagnosis by CT for metastasis of the greater curvature group was 50% and the accuracy was 87%, these percentages being better than those by US and EUS. Moreover the sensitivity by US was only 8%. Therefore it seemed to be difficult to diagnose lymph node metastasis of greater curvature group by diagnostic imaging. The sensitivity by CT for the metastasis of the celiac artery group was 67% which was the best result. In conclusion the combination diagnosis of CT, US and EUS is essential for the evaluation of lymph node metastasis, and the grading of lymph node dissection at operation should be determined carefully, because there is a limitation of the ability of diagnostic imagings. (author)