Imaging a pancreatic carcinoma xenograft model with 11C-acetate: a comparison study with 18F-FDG

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 (C-11-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 C-11-acetate and fluorine-18-labeled fluorodeoxyglucose (F-18-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 C-11-acetate-PET than that in F-18-FDG-PET. Peak T/N ratio was obtained at the 5th week in C-11-acetate-PET and at the 4th week in F-18-FDG-PET. T/N ratio in C-11-acetate-PET was lower than that in F-18-FDG-PET during the same period. By visual evaluation, tumor xenografts were more easily observed in C-11-acetate-PET than in F-18-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 F-18-FDG-PET Tumor size, T/N ratio in C-11-acetate-PET, and T/N ratio in F-18-FDG-PET were not found to be significantly correlated with tumor proliferating cell nuclear antigen expression. Conclusion C-11-acetate-PET imaging can be used for the detection of pancreatic carcinoma. In the early stage of tumor growth, C-11-acetate-PET has better detectability than that of F-18-FDG-PET. Nucl Med Commun 30:971-977 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.