ASSESSMENT OF PANCREATIC PARENCHYMAL INVASION BY BILE-DUCT CANCER USING INTRADUCTAL ULTRASONOGRAPHY

Background and Study Aims: This study was performed to clarify the dia gnostic accuracy of intraductal ultrasonography (IDUS) in assessing pa ncreatic parenchymal invasion by bile duct cancer, Patients and Method s: Preoperative assessment of pancreatic parenchymal invasion was carr ied out by IDUS via a percutaneous tract or a transpapillary route in 18 patients with extrahepatic bile duct cancer, Various probes with di ameters of 1.4, 2.0, 2.4, 2.6 and 3.2 mm, and frequencies of 7.5, 15, 20 and 30 MHz were used, All patients underwent angiography and endosc opic ultrasonography (EUS), In the first six cases, IDUS and EUS image s were analyzed retrospectively without knowledge of the operative out come or the results of other imaging tests, In the subsequent 12 cases , the IDUS und EUS images were prospectively reviewed prior to surgery . The diagnostic accuracy of IDUS was compared with angiography and EU S by means of a histopathological examination of the resected specimen s. Results: The accuracy of IDUS, EUS, and angiography in assessing pa ncreatic parenchymal invasion was 100%, 78% and 61%, respectively, How ever, IDUS could not assess pancreatic capsular invasion. The accuracy of IDUS in assessing horizontal tumor extension to the intrapancreati c bile duct and to the hepatic side was 83% and 72%, respectively. Con clusions: IDUS proved useful for assessing the extension of cancer inv asion to the pancreatic parenchyma, but not to the pancreatic capsule or mucosal surface.