Preoperative multidetector-row computed tomography scan staging for lymphatic gastric cancer spread

Background: Multidetector-row computed tomography (MDCT) is commonly used to stage patients with gastric cancer, even though the technique often shows low specificity for lymph-node involvement. Methods: In this study, 111 patients with gastric cancer who consecutively underwent MDCT scan followed by radical surgical treatment at our hospital were retrospectively evaluated. Results: In total, 3632 lymph nodes from 643 lymphatic stations were studied and then correlated with radiological features. Lymph-node size was not always associated with infiltration. Of the 261 lymph-node stations that were not radiologically detected, 60 (22.9%) were infiltrated. There were 108 stations with lymph nodes larger than 10 mm seen on MDCT, of which 67 (62%) had lymphatic invasion. The sensitivity was 32.6%, specificity 90.6%, positive predictive value 62.0%, negative predictive value 74.2%, and accuracy 72.1%. When three lymph nodes, at least one of which was larger than 10 mm, were detected in the same station, infiltration was confirmed with 99% specificity in 93.8% of patients. Moreover, all of the 13 patients in whom three lymph nodes larger than 10 mm were detected in different neighboring stations had lymphatic invasion. Conclusions: Although presence of lymph nodes greater than 10 mm in size is not, in itself, sufficient to confirm lymphatic invasion, nodal involvement can be hypothesized when associated images are detected by MDCT.