THE USE OF HELICAL CT AND CT ANGIOGRAPHY TO PREDICT VASCULAR INVOLVEMENT FROM PANCREATIC-CANCER - CORRELATION WITH FINDINGS AT SURGERY

OBJECTIVE. The purpose of this study was to test the accuracy of helic al CT with and without CT angiography to predict vascular involvement from pancreatic cancer and correlate the resultant images with finding s at surgery. SUBJECTS AND METHODS. Helical CT and CT angiography was done in 84 patients who had adenocarcinoma of the pancreas to refine a n integrated helical CT angiography protocol. Of these patients, 38 un derwent radical pancreatoduodenectomy. Vessel integrity of the superio r mesenteric artery, superior mesenteric vein, and portal vein was ass essed prospectively on both axial CT scans and CT angiograms and corre lated with findings at surgery and in particular with the ability of t he surgeon to dissect the tumor from these vessels along the vascular planes. RESULTS. CT angiograms were obtained in 82 (98%) of 84 studies . Of the 38 patients pancreatoduodenectomy, resection was aborted in 1 1 (29%) because of vascular encasement. Compared with axial CT images, CT angiography was more accurate at revealing unresectable cases. In all but one of 11 patients with vessel encasement (narrowing of the lu men) revealed on CT angiography, the lesion was unresectable. Vessel e ncasement was shown in only two of these 11 patients on axial CT image s (of these two patients, one underwent tumor resection.) The negative predictive value of a resectable tumor was 96% for CT angiography and axial helical CT compared with 70% for axial helical CT images alone (p =.021).CONCLUSION. Helical CT with CT angiography of the pancreas p rovides useful information about local vascular involvement from pancr eatic carcinoma. Compared with conventional axial helical CT, the addi tion of CT angiography improves radiologists' ability to predict the r esectability of pancreatic tumors.