HYDRO-CT IN THE DETECTION AND STAGING OF PANCREATIC-CARCINOMA

Purpose: To document our experience with spiral hydro-CT of the pancre as based on a combination of pharmacologic intestinal paralysis and wa ter distension of the stomach and duodenum with specific reference to tumor detection rate, differentiation of malignant versus benign tumor s and assessment of tumor resectability in a prospective study on 211 consecutive patients. Material and methods: Between May 1994 und Septe mber 1997, 211 patients with suspect of pancreatic neoplasm from clini cal, laboratory or other imaging data were examined. Our Hydro-CT tech niques were based on intravenous injection of 40 mg N-butylscopolamini umbromid (Buscopan) for intestinal paralysis, gastric and duodenal wal l distension by oral administration of an average of 1.5 l warm tap wa ter, 30 degrees RAO patient's positioning, individualized contrast inj ection technique using portal vein enhancement as reference and thin s lice spiral CT (3 mm slice thickness, 6 mm table feed and 3 mm seconda ry reconstruction). Examined parameters were: (1) tumor detection rate , (2) differentiation of malignant versus benign disease, (3) differen tial diagnosis and (4) accuracy of assessment of resectability by iden tification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, porta l vein and celiac trunk, superior mesenteric, splenic and hepatic arte ries. As gold standard for positive tumor detection and description su rgery (of potentially resectable tumors) and microscopic diagnosis (of clearly unresectable tumors) were used and for negative tumor detecti on an event-free survival of six months, respectively. Results: 96% of the examinations were well tolerated. In only 4% was on-site administ ration of a gastric tube required because of vomiting. In 2% of the pa tients a slight allergic reaction to the contrast medium was seen. The prevalence of a pancreatic neoplasm was 37,8%. In tumor detection Hyd ro-CT reached an overall accuracy of 94,8% with a sensitivity of 93,7% and a specificity of 95,2%. 52 patients underwent surgical exploratio n 34 of whom with tumorfree resection margins (RO resection) correspon ding to a resection of 42,5%. In those assessment of resectability rea ched an overall accuracy of 94,6% with a sensitivity of 91,2% and spec ificity of 95,6%. Conclusion: The new technique of Hydro-CT based on t hin slice and spiral methodology including pharmacologic intestinal pa ralysis and water distension results in a high tumor detection rate an d reliable assessment of resectability.