CT arterial portography in the staging of pancreatic malignancy.

BACKGROUND: Detection of metastatic liver disease and malignant involvement of major peripancreatic vessels is important to determine resectability of pacreatic malignancy. Computed tomography with arterial portography (CTAP) is the most sensitive method for detection of colorectal liver metastases; it can also detect malignant vascular involvement. We have assessed CTAP in patients with pancreatic cancer considered suitable for resection after standard ultrasonography (US) and computed tomography (CT) examination.
METHOD: CTAP was performed in 18 patients (8 with a biliary stent). All patients had previous US and CT with no clear evidence of irresectability. Findings of CTAP were compared with the prior CT and with findings at operation or clinical progress.
RESULTS: CTAP suggested liver metastases in 7 patients. Three were confirmed at operation or at follow-up (sensitivity for detection of metastases in CT negative patients of 75%). There were 4 false-positive assessments (specificity, 71%). One further patient developed liver metastases within 6 mo after resection (1 false-negative). Nine patients had vascular involvement at operation. There was 1 false-positive and one false-negative assessment (sensitivity, 89% and specificity, 89%). CTAP detected vascular involvement in 4 patients in whom it was not detected by CT.
CONCLUSION: This preliminary study suggests that CTAP is a sensitive test for detection of liver metastases and vascular involvement in patients with pancreatic malignancy. This invasive test should be reserved for patients who are considered operable on the basis of other preoperative tests.