¹¹C-choline PET/CT Imaging And The Change Of Choline Metabolism In Lung Cancer

Objective:Positron emission tomography (PET) is able to image the metabolic differences between normal and malignant cells using tumor-seeking tracers. 18F-fluorodeoxyglucose (18F-FDG) is the most commonly used tracer of this kind. But the sensitivity is high and specificity is low of 18F-FDG PET. It is difficulty to distinguish patients with lung cancer from those with pulmonary inflammation lesions using 18F-FDG..11C-choline is another tracer that has been used for imaging malignancies. This study is to investigate the 11C-choline PET/CT imaging of lung cancer and the change of choline metabolism in the cells of lung cancer.Methods:11C-choline positron emission tomography and computed tomography (PET/CT) imaging was performed in 18 patients with the lung cancer confirmed by operation and pathology. RT-PCR and Western blot were used to investigate the expression of choline acetyltransferase (ChAT) and choline kinase (ChoK) genes in lung cancer specimens and the normal lung tissues. Results:The uptake of 11C-choline was increased in all the lesions.In 18 patients,the mean Standardized uptake value (SUVmean) was 3.55±1.63(1.17～5.84) and the maximum Standardized uptake value (SUVmax) was 4.24±1.92(1.29～6.67), T/NT of SUV was 5.78±1.85 (2.97～9.84). The difference was not statistically significant between the squamous cell carcinoma and adenocarcinoma in in the SUVmean,SUVmax and T/NT value (t=0.512,P=0.618＞0.05; t=0.325,P=0.75＞0.05; t=1.987,P=0.07＞0.050).The expression of ChAT mRNA and protein were enhanced in 9 of 18 lung tumor specimens; and the expression of ChoK mRNA and protein were increased in 14 of 18 lung tumor specimens comparing with the normal lung tissues. Eight of 18 lung cancer specimens were obvious increased both in the expression of ChoK and in the expression of ChAT.Conclusion:There is abnormal high uptake of 11C-choline in the lung cancer, and the activity of both ChAT and ChoK were increased in the cells of the lung cancer.