Computed tomography evaluation of regional lymph node metastases in patients with biliary cancer

Abstract

Identification of lymph node metastases in biliary cancer is important for determining prognosis and surgical planning, but the effectiveness of computed tomography (CT) in diagnosing node metastases of the hepatoduodenal ligament (peribiliary and retroportal nodes) or around the common hepatic artery is unknown. CT scans and pathological results from 146 patients who had undergone regional lymphadenectomy for biliary carcinoma were reviewed. To evaluate the regional lymph nodes, long- and short-axis diameters of lymph nodes were measured and axial ratios calculated (short-axis diameter/long-axis diameter). Nodes were considered round if the axial ratio exceeded 0.7. Internal lymph node structures were also evaluated. The presence of a round node with a short-axis diameter exceeding 16 mm had a positive predictive value (PPV) of 56 per cent for the presence of metastatic foci, and node heterogeneity had a PPV of 64 per cent. The highest PPV (67 per cent) was obtained for round nodes greater than 18 mm in short-axis diameter, but nodes of this size and character were rare. CT is not useful for predicting regional lymph nodal metastases in biliary carcinoma.