Helical computed tomography in the diagnosis of portal vein invasion by pancreatic head carcinoma: Usefulness for selecting surgical procedures and predicting the outcome

Objective: To evaluate the use of helical computed tomography (CT) in diagnosing portal vein (PV) invasion by pancreatic head carcinoma and its usefulness in predicting outcome. Design: Validation cohort study. Setting: Tertiary care public hospital. Patients: Twenty-seven patients with carcinoma involving the pancreatic head were preoperatively studied with helical CT. All patients underwent resection. Main Outcome Measure: By quantifying the contact between the tumor and PV on helical CT, the relationship between them was classified into 1 of 4 types: type 1, visible fat layer between PV and the tumor; type 2, with the total PV circumference defined as 360°, contact between the tumor and PV was considered to be 90°or less; type 3, contact ranged between 91°and 180°; and type 4, contact greater than 180°. Helical CT results were compared with intraoperative observation, histological findings of the resected specimen, and postoperative course. Results: When helical CT showed type 3 or 4, the case was diagnosed as positive for PV invasion. Sensitivity, specificity, and overall accuracy were 83%, 100%, and 89% when compared with the intraoperative assessment, and 92%, 79%, and 85% with the histological assessment, respectively. One- and 2-year survival rates were 86% and 69% for type 1,100% and 75% for type 2, and 33% and 12% for type 3, respectively. The survival rates of patients with types 1 and 2 were significantly higher than that of those with type 3 (P<.05). All 3 patients with type 4 died within 9 months. Conclusions: Helical CT facilitates detection of PV invasion by pancreatic head carcinoma. The extent of PV involvement reflected the outcome after pancreatectomy.