title: Is (18)F-fluorodeoxyglucose positron emission tomography meaningful for estimating the efficacy of corticosteroid therapy in patients with autoimmune pancreatitis?
abstract: BACKGROUND
  Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic cancer (PC). Both conditions accumulate (18)F-fluorodeoxyglucose (FDG), so FDG positron emission tomography (FDG-PET) is not discriminatory. This study aimed to evaluate the pattern of FDG accumulation, and the change in FDG uptake after steroid treatment in AIP and PC.
  
  
  METHODS
  We compared FDG-PET patterns between 18 patients with AIP and 20 patients with PC, and also evaluated the short-term changes in FDG uptake after steroid therapy.
  
  
  RESULTS
  FDG uptake was observed in 88.9% in AIP and 90.0% in PC. FDG uptake in extra-abdominal lymph nodes was seen more frequently in AIP, and uptake in salivary glands, eyes and biliary ducts was seen only in AIP. Follow-up PET was performed in 6 AIP patients and in 3 PC patients. Changes in SUV(max) after steroid therapy were estimated within 1 week in 5 AIP patients and in all 3 PC patients, retrospectively. In 4 AIP patients, the change in SUV(max) was more than 10%. On the other hand, in PC, SUV(max) increased or remained almost unchanged (within 10%).
  
  
  CONCLUSIONS
  FDG-PET pattern at baseline, and a decrease in FDG uptake after a short steroid trial can be useful for discriminating AIP from PC.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan. m-shigekawa@gh.med.osaka-u.ac.jp
authors.forename: Minoru
authors.initials: M
authors.lastname: Shigekawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
authors.forename: Akira
authors.initials: A
authors.lastname: Sawaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Takagi
authors.forename: Vikram
authors.initials: V
authors.lastname: Bhatia
authors.forename: Masami
authors.initials: M
authors.lastname: Nishio
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Tamaki
authors.forename: Hussein
authors.initials: H
authors.lastname: El-Amin
authors.forename: Zain El-Abdeen Ahmed
authors.initials: Zel-A
authors.lastname: Sayed
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Mizuno
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D010195:Pancreatitis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18