[Value of spiral computed tomography for the preoperative detection of lymph node involvement in gastric cancer]

Knowledge regarding the presence of metastatic lymph node in gastric cancer is of obvious importance when thinking of neoadjuvant therapy, yet it is full of uncertainty. Computed tomography (CT) is one of the first-line diagnostic tools, in spite of controversial results. We aimed to establish the performance of spiral CT in predicting lymph node involvement in gastric cancer.

Sixty-two consecutive patients diagnosed of gastric cancer were enrolled in the study. All the patients were examined by CT and imaging results were compared with the corresponding histopathological findings following surgery. We analyzed the sensitivity, specificity, positive and negative reasons, accuracy and efficiency. We also assessed the distribution and number of isolated lymph nodes, the diameter of the largest single nodes and the N distribution according the TNM classification system.

Compared with the histological results, CT achieved a sensitivity of 0.43, specificity of 0.96, an accuracy of 0.55 and an efficiency of 0.67. An in-depth analysis of the histological lymph node size revealed significant differences between the groups with and without lymph node involvement, with an average size of 16.29mm (95% confidence interval, 7.1-15.6) and 10.25mm (95% confidence interval, 4.8-25.5), respectively (p<0.05). We also observed a diminished accuracy for the N1 and N2 groups.

Spiral CT shows a poor performance for the preoperative evaluation of lymph node involvement. Nevertheless, in case of a positive result, spiral CT is helpful for treatment decision-making in gastric cancer as a first-line staging technique.