Quantitative comparison of 68Ga-NGR and 18F-FDG uptake in well-differentiated hepatocellular carcinoma bearing mice / 中华核医学与分子影像杂志

ABSTRACT

Objective To quantitatively compare the diagnostic capability of 68Ga-NGR and 18F-FDG in well-differentiated hepatocellular carcinoma (HCC) bearing mice by microPET/CT imaging.Methods The in vitro cellular uptake,in vivo microPET/CT imaging and biodistribution studies of 68Ga-NGR and 18F-FDG were quantitatively compared in SMMC-7721-based well-differentiated HCC.The human fibrosarcoma (HT-1080) and human colorectal adenocarcinoma (HT-29) cells/xenografts were respectively used as positive and negative reference groups for CD13.The expression of CD13 was qualitatively verified by immunohistostaining.The levels of CD13 and glucose-6-phosphatase (G6Pase) were semi-quantitatively analyzed by Western blot test for all 3 types of tumors.Two-sample t test was used for data analysis.Results The in vitro cellular uptake showed that the 68Ga-NGR uptake in SMMC-7721 and HT-1080 cells was higher than that in HT-29 cells,and the 68Ga-NGR uptake was higher than 18F-FDG uptake in SMMC-7721 cells.The in vivo micro-PET/CT imaging results revealed that the uptake of 68Ga-NGR in SMMC-7721 tumor was (2.17±0.21) ％ID/g,remarkably higher compared to (0.73±0.26) ％ID/g of 18F-FDG uptake (t =8.826,P＜0.01).The tumor/liver ratio of 68Ga-NGR was 2.05±0.16,which was 2.03-fold higher than that of 18F-FDG.In the HT-1080 tumors,the uptakes of 68 Ga-NGR and 18F-FDG were both high,and the values were (2.46±0.23) ％ID/g,(3.47±0.31) ％ID/g.The uptake of 68Ga-NGR was significantly lower than that of 18F-FDG in HT-29 tumors(0.67±0.20) ％ID/g vs (3.17±0.29) ％ID/g;t=4.221,P＜0.01.Western blot and immunohistostaining results were as followsHT-1080(CD13+,G6Pase-),SMMC-7721(CD13+,G6Pase+),HT-29 (CD13-,G6Pase-).Conclusions The uptake of 68Ga-NGR is higher than 18F-FDG uptake in SMMC-7721 tumor bearing mice,therefore it is worthwhile to consider the feasibility of clinical translation for PET/CT in diagnosis of HCC.Furthermore,because of the difference in 68Ga-NGR and 18F-FDG avidities in tumors with different molecular phenotypes of CD13 and G6Pase,there is an underlying potential for molecular imaging in the determination of molecular phenotypes.