11C-胆碱和18F-FDG PET反映兔VX2肺肿瘤增殖活性的对比研究

objective Tumor proliferative activity has been recognized as an indicator of malignant degree in lung cancer and related to prognosis.The purpose of this study was to evaluate the feasibility of assossing proliferative activity with 11C-choline and 18F-fluorodeoxyglucose(FDG)PET on a rabbit beating lung VX2 tumor model.Methoils About 0.5 ml of viable VX2 tumor cell suspension was slowly injected into the right lungs of 54 New Zealand white rabbits through a transthoracical needle insertion.11C-choline and18F-FDG PET scan were performed 10-11 d after tumor implantation.One ear vein was cannulated for administration of the tracem.11C-choline PET scan(with Discovery LS PET/CT scanner,GE)was performed 5 min after intravenously injection of 37 MBq11C-choline.Then 18.7 MBq18F-FDG was infused at 60 min after11C-choline administration and18F-FDG PET scan was performed at 60 min after18F-FDG administration.The maximal standardized uptake value of tumor was calculated.The animals were euthanized after examination.Histochemical stain with proliferating cell nuclear antigen(PCCNA)was performed and PCNA index was obtained to assess tumor prolireration.The difference of11C-choline and18F-FDG was analvzed using paired student t-test.The correlation of 11C-choline 18F-FDG and tumor cell density and PCNA index was analyzed using Pearson Iinear regression.Results Of the 54 rabbits.36 had a solitary pulmonary tumor.The rate of successful generation of a solitary VX2 tumor was 66.7%(36/54).Only 33 rabbits underwent both 11C-choline and 18F-FDG PET,and enrolled in this study.The mean cellular density was (547.36±64.78) cells/field and the mean PCNA index was(42.34±15.26)%.18F-FDG was hisher than 11C-choline(5.70±3.45 vs 4.02±3.07,t=-3.188,P=0.003).11C-choline significantly and positively correlated with PCNA index(r=0.786,P＜0.05).However,there was no significant correlation between 11C-choline and tumor cellular density(r=-0.176,P=0.327).18F-FDG significantly and positively correlated to PCNA index(r=0.531.P=0.001).There was no significant correlation between 18F-FDG and cellular density(r=-0.105.P=0.561).Conclusions In a rabbit bearing lung VX2 tumor model,11C-choline or 18F-FDG uptake correlates with PCNA index.Thus PET scan with these two tracers may reflect tumor proliferative activity.11C-choline PET may be more reliable to evaluate tumor proliferation than 18F-FDG PET.

Correlation between 11C-choline or18F-FDG uptake and tumor proliferation:a rabbit bearing lung cancer model study