Is post-lipiodol CT better than IV contrast CT scan for early detection of HCC? A single liver transplant center experience

Hepatocellular carcinoma is a highly vascular neoplasm usually arising from a cirrhotic liver. Delayed, noncontrast, computed tomography (CT) imaging after 7 to 14 days reveals an oil-based contrast agent to be concentrated in the tumor but not in normal hepatic parenchyma. The aim of this study was to retrospectively correlate the post Lipiodol CT scan findings with respect to tumor size in the explanted liver. We retrospectively reviewed adult patients who had undergone orthotopic liver transplantation between November 1995 and December 2004 and also had an hepatic arteriogram with Lipiodol injection as part of their pretransplant workup. We calculated sensitivity, specificity, false-negativity, false-positivity, and accuracy of the test, as well as positive and negative predictive values. Lipiodol CT exam had sensitivity of 1.0; specificity of 0.6 with a calculated positive predictive value of 0.89 and a negative predictive value of 1.0. Overall accuracy of Lipiodol CT scan test was found to be 0.91, which was superior to an intravenous contrast CT alone. In conclusion, because of the higher sensitivity and accuracy values, hepatic arterial Lipiodol injection can be considered during the pretransplantation workup of high-risk cirrhotic patients, since the current model for End-stage Liver Disease scoring system for hepatocellular carcinoma is built on the ultimate bulk of the tumor. Further multicenter, controlled, large-volume prospective studies are warranted to verify this observation.