title: The possible role of F-18 FDG positron emission tomography in the differential diagnosis of focal pancreatic lesions.
abstract: OBJECTIVE
  To compare the diagnostic values of different methods for the differentiation of malignant from benign pancreatic lesions.
  
  
  METHODS
  In 22 patients with focal pancreatic lesions, the carbohydrate antigen (CA) 19-9 level was measured; abdominal ultrasound (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were performed; and the value of these methods were analyzed for their use in cancer diagnosis.
  
  
  RESULTS
  Malignant lesions were identified in six patients and verified by surgery or clinical follow-up. The CA 19-9 level was elevated in four of the five patients examined (sensitivity, 80%). In all six cases, US and CT revealed hypoechogenic and hypodense areas (sensitivity, 100%). In one patient, ERCP was unsuccessful but yielded true-positive results in three others (sensitivity, 60%). The sensitivity of FDG PET was 100%. Sixteen focal cases of pancreatic disease proved to be benign. The CA 19-9 level was elevated in four of them (specificity, 73%). Hypoechogenic and hypodense areas were evident on US and CT in eight patients. The specificity of CT was 50% (8 of 16 cases). The specificity of US was 47% (7 of 15 cases). The specificity of successful ERCP was 92%. Fourteen negative FDG-PET results were truly negative. In two patients, however, the PET findings proved to be falsely positive (specificity, 88%).
  
  
  CONCLUSIONS
  FDG-PET is an effective tool to differentiate malignant from benign focal pancreatic lesions. In persons with focal pancreatic hypoechogenic or hypodense lesions detected by CT or US and an elevated CA 19-9 level, FDG PET should be the next step in the diagnostic strategy.
authors.affiliation: Department of Nuclear Medicine, First Department of Medicine, University of Szeged, Szeged, Hungary. paposm@comser.szote.u-szeged.hu
authors.forename: Miklós
authors.initials: M
authors.lastname: Papós
authors.forename: Tamás
authors.initials: T
authors.lastname: Takács
authors.forename: Lajos
authors.initials: L
authors.lastname: Trón
authors.forename: Gyula
authors.initials: G
authors.lastname: Farkas
authors.forename: Edit
authors.initials: E
authors.lastname: Ambrus
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Szakáll
authors.forename: János
authors.initials: J
authors.lastname: Lonovics
authors.forename: László
authors.initials: L
authors.lastname: Csernay
authors.forename: László
authors.initials: L
authors.lastname: Pávics
mesh_terms: D000328:Adult; D018395:CA-19-9 Antigen / Q000032:analysis; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003937:Diagnosis, Differential; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology / Q000601:surgery; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D018395:CA-19-9 Antigen; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18