title: Defining a role for endoscopic ultrasound in staging periampullary tumors.
abstract: BACKGROUND
  The goal of the preoperative workup in patients with suspected periampullary carcinoma is to establish the diagnosis with a high degree of certainty. In this study we compared endoscopic ultrasonography (EUS) and computed tomography (CT) scans for the detection of tumor, lymph node metastasis, and vascular invasion in patients with suspected periampullary carcinoma in order to define a role for EUS in the preoperative staging of these patients.
  
  
  METHODS
  Thirty-seven consecutive patients received EUS and CT scanning followed by operation for presumed periampullary carcinoma during a 30-month period. Both imaging modalities were reviewed in a blinded fashion and the results compared with pathology and operative reports on all patients.
  
  
  RESULTS
  Sensitivity, specificity, positive predictive value, and negative predictive value for tumor detection by EUS were 97%, 33%, 94%, and 50%, respectively, compared with 82%, 66%, 97%, and 25% for CT scan. For lymph nodes the values were 21%, 80%, 57%, and 44%, respectively, for EUS compared with 42%, 73%, 67%, and 50% for CT. For vascular invasion, the values were 20%, 100%, 100%, and 89%, respectively, for EUS, compared with 80%, 87%, 44%, and 96% for CT.
  
  
  CONCLUSIONS
  CT is the initial study of choice in patients with suspected periampullary tumors. EUS is superior for detecting tumor and for predicting vascular invasion. Therefore, EUS should be used for patients in whom CT does not detect a mass and for those with an identifiable mass on CT in whom vascular invasion cannot be ruled out.
authors.affiliation: Department of Diagnostic Radiology, Division of Gastroenterology, and Department of Surgery, Section of Surgical Oncology, Loyola Stritch School of Medicine, Maywood, Illinois, USA.
authors.forename: M
authors.initials: M
authors.lastname: Shoup
authors.forename: P
authors.initials: P
authors.lastname: Hodul
authors.forename: G V
authors.initials: GV
authors.lastname: Aranha
authors.forename: D
authors.initials: D
authors.lastname: Choe
authors.forename: M
authors.initials: M
authors.lastname: Olson
authors.forename: J
authors.initials: J
authors.lastname: Leya
authors.forename: J
authors.initials: J
authors.lastname: Losurdo
mesh_terms: D000328:Adult; D000368:Aged; D014670:Ampulla of Vater / Q000473:pathology* / Q000601:surgery; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed