title: Comparison of International Consensus Guidelines versus 18-FDG PET in detecting malignancy of intraductal papillary mucinous neoplasms of the pancreas.
abstract: OBJECTIVE
  To assess the reliability of the International Consensus Guidelines (ICG) and 18-fluorodeoxyglucose positron emission tomography (PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.
  
  
  BACKGROUND
  Since 2006 the ICG have been used to choose immediate surgery or surveillance for IPMN patients, but their low specificity increases the number of benign IPMNs that undergo resective surgery. PET has proved highly sensitive and specific in detecting malignancy in cystic neoplasms of the pancreas, including IPMNs.
  
  
  METHODS
  Patients suspected with IPMNs of the pancreas seen at our Department from January 1989 to July 2010 were identified and classified as cases of main duct, mixed type and branch type IPMN. The indication for resection or surveillance was verified a posteriori for all patients according to the ICG. PET was considered positive for a Standardized Uptake Value ≥2.5. Surveillance included clinical examination, laboratory tests, CA 19-9 serum levels, and computed tomography and/or magnetic resonance and magnetic resonance cholangiopancreatography every 6 months for 2 years and yearly thereafter. Endoscopic ultrasound was rarely performed. PET was repeated in clinically or radiologically suspect cases, or if tumor markers increased.
  
  
  RESULTS
  Sixty-one main duct or mixed type and 101-branch type IPMNs were included in the study. A histological diagnosis was available for 81 of 162 patients, missing for 1 locally advanced IPMN, whereas 62 patients are under surveillance and it proved impossible to contact 18. Conservative surgery was performed in 16 of 68 patients with benign IPMNs. The sensitivity, specificity, positive and negative predictive value, and accuracy of the ICG in detecting malignancy were 93.2, 22.2, 59.4, 72.7, and 61.2, whereas for PET they were 83.3, 100, 100, 84.6, and 91.3.
  
  
  CONCLUSIONS
  PET is more accurate than the ICG in distinguishing benign from malignant (invasive and noninvasive) IPMNs. Prophylactic IPMN resection in young patients fit for surgery should be guided by the ICG, whereas PET should be performed in older patients, cases at increased surgical risk, or when the feasibility of parenchyma-sparing surgery demands a reliable preoperative exclusion of malignancy.
authors.affiliation: IV Surgical Clinic, Department of Medical and Surgical Sciences, University of Padua, Padova, Italy. sergio.pedrazzoli@unipd-it
authors.forename: Sergio
authors.initials: S
authors.lastname: Pedrazzoli
authors.forename: Cosimo
authors.initials: C
authors.lastname: Sperti
authors.forename: Claudio
authors.initials: C
authors.lastname: Pasquali
authors.forename: Sergio
authors.initials: S
authors.lastname: Bissoli
authors.forename: Franca
authors.initials: F
authors.lastname: Chierichetti
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging* / Q000473:pathology; D000231:Adenocarcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D019983:Guideline Adherence; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D019788:Fluorodeoxyglucose F18