title: Clinical utility of 2-[(18)F] fluoro-2-deoxy-D-glucose positron emission tomography in predicting World Health Organization grade in pancreatic neuroendocrine tumors.
abstract: BACKGROUND
  Pancreatic neuroendocrine tumors (PNETs) present various histologic stages, and their clinical behavior ranges from benign to highly aggressive. World Health Organization (WHO) grading categorizes PNETs into 3 groups (G1, G2, and G3) based on proliferative activity. The aim of this study was to assess the clinical utility of 2-[(18)F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in preoperative differential diagnosis for various histologic grades of PNETs and in predicting postoperative prognosis in PNET patients.
  
  
  METHODS
  We investigated prospectively 36 patients who underwent preoperative FDG-PET, received surgery for PNETs, and had resected specimens examined via histology. The maximum standardized uptake value (SUVmax) was determined on FDG-PET, and differentiating power between G1/G2 and G3 PNETs was examined using various SUVmax cutoff levels. We also evaluated the prognostic impact of FDG-PET findings using postoperative survival data.
  
  
  RESULTS
  SUVmax significantly correlated with WHO grade (Spearman rank correlation 0.584; P = .0018), and the SUVmax of G3 tumors (5.0 ± 2.5; n = 4) was significantly higher than that of G1/G2 tumors (2.7 ± 1.6; n = 32; P = .0159). Using 2.5 as a cutoff SUVmax, the sensitivity, specificity, and accuracy of differentiating G3 tumors from G1/G2 tumors were 100.0%, 62.5%, and 66.7%, respectively. Furthermore, the SUVmax of FDG-PET (<2.5 vs ≥2.5) was significantly related to postoperative disease-free survival (P = .0463).
  
  
  CONCLUSIONS
  These results suggest that FDG-PET may be useful for differentiating G3 PNETs from G1/G2 PNETs and for predicting postoperative prognosis in PNET patients. This preliminary finding is expected to be confirmed by prospective validation with more patients.
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tomimaru
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Eguchi
authors.affiliation: Department of Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Tatsumi
authors.affiliation: Department of Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Tonsok
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hama
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kawamoto
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Department of and Pathology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Morii
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Doki
authors.affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. Electronic address: hnagano@gesurg.med.osaka-u.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagano
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014944:World Health Organization
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18