Conventional 18F-FDG PET/CT has important diagnostic value in cell metabolism level, early metastasis, judging malignant potential and prognosis of tumors. It has been routinely used for staging and restaging of most tumors, but there are still some tumors with low uptake of 18F-FDG PET/CT. Moreover, 18F-FDG cannot distinguish between tumors and inflammatory diseases, such as tuberculosis and granuloma. Receptor imaging with a single target also has some limitations in clinical application. For example, not all diseased cells express a large amount of single receptor on the surface, which greatly affects the judgment of the nature of the lesion. The dual-target molecular imaging based on FAP expressed in the lesion site and integrin αvβ3 receptor highly expressed on the surface of the lesion neovascularization will overcome the above limitations and make full use of the advantages of the dual-target molecular imaging, which will greatly assist the diagnosis of malignant tumors such as lung cancer. In this study, a novel dual-target imaging agent 68Ga-FAPI-RGD was used for PET/CT imaging of lung cancer, compared with conventional 18F-FDG, or single target imaging agent 68Ga-RGD or 68Ga-FAPI PET/CT imaging.
Based on the high expression of specific receptors on the surface of diseased tissues and neovascularization, noninvasive targeted molecular imaging can be used to visualize lesions in vitro by combining specific ligands labeled with short half-life isotopes. Lung cancer tissues express fibroblast activating protein FAP, and also have high expression of integrin αVβ3 receptor on the surface of blood vessels. In this study, a novel dual-target imaging agent 68Ga-FAPI-RGD was used for PET/CT imaging of lung cancer.