title: Imaging a pancreatic carcinoma xenograft model with 11C-acetate: a comparison study with 18F-FDG.
abstract: OBJECTIVE
  Pancreatic carcinoma is a malignant tumor with poor prognosis and its early detection is still a clinical problem. The aim of this study was to evaluate the efficacy of carbon-11-labeled acetate (11C-acetate)-positron emission tomography (PET) for the detection of pancreatic carcinoma in a BxPC-3 human pancreatic carcinoma xenograft-bearing immunodeficiency BALB/c-nu nude mice model.
  
  
  METHODS
  Whole-body 11C-acetate and fluorine-18-labeled fluorodeoxyglucose (F-FDG) micro-PET imaging were performed weekly on BxPC-3 human pancreatic carcinoma xenograft-bearing BALB/c-nu nude mice from the 2nd week after tumor cell inoculation. Regions of interest method and tumor-to-nontumor ratio (T/N ratio) were used for semiquantitative evaluation. Tumor proliferation was evaluated by immunohistochemistry analysis of proliferating cell nuclear antigen.
  
  
  RESULTS
  Radiotracer accumulation in the tumor xenografts could be detected 1 week earlier in 11C-acetate-PET than that in 18F-FDG-PET. Peak T/N ratio was obtained at the 5th week in 11C-acetate-PET and at the 4th week in 18F-FDG-PET. T/N ratio in 11C-acetate-PET was lower than that in 18F-FDG-PET during the same period. By visual evaluation, tumor xenografts were more easily observed in 11C-acetate-PET than in 18F-FDG-PET in most of the mice. Linear correlation analysis indicated T/N ratios in C-acetate-PET had no significant correlation with those in 18F-FDG-PET. Tumor size, T/N ratio in 11C-acetate-PET, and T/N ratio in 18F-FDG-PET were not found to be significantly correlated with tumor proliferating cell nuclear antigen expression.
  
  
  CONCLUSIONS
  11C-acetate-PET imaging can be used for the detection of pancreatic carcinoma. In the early stage of tumor growth, 11C-acetate-PET has better detectability than that of 18F-FDG-PET.
authors.affiliation: Department of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Zhao
authors.forename: Zhanhong
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Ye
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhan
authors.forename: Tamio
authors.initials: T
authors.lastname: Aburano
authors.forename: Mei
authors.initials: M
authors.lastname: Tian
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000085:Acetates / Q000138:chemical synthesis; D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000818:Animals; D002244:Carbon; D002250:Carbon Radioisotopes; D045744:Cell Line, Tumor; D019788:Fluorodeoxyglucose F18 / Q000138:chemical synthesis; D006801:Humans; D007150:Immunohistochemistry; D007553:Isotope Labeling; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis / Q000235:genetics; D019275:Radiopharmaceuticals / Q000138:chemical synthesis
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; D018809:Proliferating Cell Nuclear Antigen; D019275:Radiopharmaceuticals; C438206:carbon-11 acetate; D019788:Fluorodeoxyglucose F18; D002244:Carbon