Adenocarcinoma of the head of the pancreas: determination of surgical unresectability with thin-section pancreatic-phase helical CT.

Abstract
This study was conducted to evaluate newly introduced criteria for unresectability of pancreatic cancer with thin-section pancreatic-phase helical CT. Twenty-five patients with adenocarcinoma in the head of the pancreas underwent thin-section pancreatic-phase helical CT. The major peripancreatic vessels were categorized on a scale of 1-4, according to the degree of circumferential involvement by tumor. The maximum diameters of the small peripancreatic veins--gastrocolic trunk, anterosuperior pancreaticoduodenal vein, and posterosuperior pancreaticoduodenal vein--were recorded. Findings on CT were compared with the results of surgery in each patient. Sixteen patients had surgically resectable tumors, and nine patients had surgically unresectable tumors. CT and surgical correlation was available for 98 major peripancreatic vessels; 85 were resectable and 13 were unresectable. Of category 1 vessels, 72 (97%) of 74 were resectable at surgery. Of category 2 vessels, 12 (71%) of 17 were resectable. One (50%) of two category 3 vessels and none (0%) of five category 4 vessels were resectable at surgery. CT showed a dilated gastrocolic trunk in two patients; one of these patients had a surgically resectable tumor, but the other patient had a surgically unresectable tumor. In patients with adenocarcinoma in the head of the pancreas, the degree of circumferential vessel involvement by tumor as shown by CT is useful in predicting which patients will have surgically unresectable tumors. A dilated gastrocolic trunk should not be used as an independent sign of surgical unresectability.