Determination of Resectability for Pancreatic Head Cancer: Based on the Suspected Vascular Invasion in Abdominal Computed Tomography

ABSTRACT

PURPOSE: To determine the resectability of pancreatic head cancer by correlating the surgical findings with those of a suspected vascular invasion by abdominal computed tomography (CT). METHODS: The portal vein, superior mesenteric vein, celiac artery, common hepatic artery and superior mesenteric artery were investigated in 100 pancreatic cancer patients who underwent two-phase CT of the pancreas. The degree of vascular encasement, luminal narrowing and the length of the involved segment were analyzed in order to correlate the surgical results. The CT findings and associated unresectable causes were analyzed in those patients who underwent the non-operative treatment. RESULTS: A surgical correlation was available in 66 patients, whose 116 vessels were examined. Vascular encasement was categorized into 5 groups (0 none, 1 < or =90 degree, 2 91~180 degree, 3 181~270 degree, 4 271~360 degree). If category 0, 1 and 2 was determined to be vascular invasion (-), the positive predictive value and negative predictive value were 91.7% and 80% in the veins, and 100% and 75.4% in the arteries. If category 0, 1, 2 and 3 in the vein were determined to be vascular invasion (-), the respective values were 100% and 75.4%. While all the arteries with narrowing were unresectable, some veins with narrowing less than 2/3 of the diameter were resectable. The mean length of the segment involved in the resectable veins was significantly shorter than that of the unresectable veins. CONCLUSION: A non-operative treatment is recommended when vascular encasement exceeds 270degree in the veins or 180 degree in the arteries, when the arteries show narrowing, or when the veins show narrowing more than 2/3 of the original diameter. A curative resection should be attempted when the vascular encasement reaches < 180degree and when the arterial narrowing is absent.