Purpose: 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 (18F-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 11C-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.
Conclusion: 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.
aDepartment of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine
bZhejiang University Medical PET Center
cThe Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University
dKey Laboratory of Medical Molecular Imaging of Zhejiang Province
eChemotherapy Center, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China
fDepartment of Radiology, Asahikawa Medical College, Asahikawa, Hokkaido, Japan
gCenter for Advanced Biomedical Imaging Research, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
Correspondence to Professor Hong Zhang, Department of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88, Jie-Fang Road, Hangzhou 310009, China
Tel/fax: +86 571 87767188; e-mail: firstname.lastname@example.org
Dr Mei Tian, Department of Experimental Diagnostic Imaging, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
Received 23 March 2009 Revised 9 July 2009 Accepted 9 July 2009