title: (18)F-FDG PET analysis of schwannoma: increase of SUVmax in the delayed scan is correlated with elevated VEGF/VPF expression in the tumors.
abstract: OBJECTIVE
  In order to clarify the increased 2-deoxy-2-fluoro-(18)F-D: -glucopyranose ((18)F-FDG) accumulation in schwannoma by positron emission tomography (PET) analysis, immunohistochemical analysis for the factors involved in glucose transportation and vascular formation was performed.
  
  
  METHODS
  Twenty-six patients with schwannoma (13 men and 13 women) with ages ranging from 27 to 75 years, who received whole body (18)F-FDG PET scan, were enrolled for the present study. The retention index (RI) was calculated by dividing the increase in the standardized uptake value (SUVmax) at the delayed scan by the SUVmax in the early scan. SUVmax and RI were compared with the histologic variables, including the expression of glucose transporters 1 and 3, hexokinase II, vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), and microvascular density shown by CD31 immunohistochemistry.
  
  
  RESULTS
  Mean SUVmax values in the early and delayed scans were 2.64 +/- 1.47 and 2.71 +/- 1.57 (mean +/- SD), respectively. RI was -2.5 +/- 21 (percentage). SUVmax showed a positive correlation with the tumor size (tumor size <5 cm, 2.06 +/- 0.72; >5 cm, 3.95 +/- 1.89; p < 0.05) and the microvascular density (negative density, 2.16 +/- 1.12; positive density, 3.56 +/- 1.67; p < 0.05). RI correlated with VEGF/VPF expression in the tumors (negative expression, -11 +/- 6.1; positive expression, 13 +/- 8.1; p < 0.05). Other factors showed no correlation with SUVmax or RI.
  
  
  CONCLUSIONS
  Microvascular density and vascular permeability of the tumor are suggested to affect the enhanced (18)F-FDG accumulation in schwannoma.
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Hamada
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomita
authors.forename: Ying
authors.initials: Y
authors.lastname: Qiu
authors.forename: Miki
authors.initials: M
authors.lastname: Tomoeda
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ueda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tamai
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hashimoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Aozasa
authors.forename: Jun
authors.initials: J
authors.lastname: Hatazawa
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D051272:Glucose Transporter Type 1 / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D018709:Statistics, Nonparametric; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D051272:Glucose Transporter Type 1; D019275:Radiopharmaceuticals; D042461:Vascular Endothelial Growth Factor A; D019788:Fluorodeoxyglucose F18; D006593:Hexokinase