A Head-to-Head Comparison of 68Ga-LNC1007 and 2-18F-FDG/68Ga-FAPI-02 PET/CT in Patients With Various Cancers

Abstract

Objectives This head-to-head comparison study was designed to investigate the radiotracer uptake and clinical feasibility of using 68Ga-LNC1007, to detect the primary and metastatic lesions in patients with various types of cancer, and to compare the results with those of 2-18F-FDG PET/CT and 68Ga-FAPI-02 PET/CT. Patients and Methods Sixty-one patients with 10 different kinds of cancers were enrolled in this study. Among them, 50 patients underwent paired 68Ga-LNC1007 and 2-18F-FDG PET/CT, and the other 11 patients underwent paired 68Ga-LNC1007 and 68Ga-FAPI-02 PET/CT. The final diagnosis was based on histopathological results and diagnostic radiology. Immunohistochemistry for FAP and integrin αvβ3 was performed in 24 primary tumors. Results 68Ga-LNC1007 PET/CT detected all 55 primary tumors, whereas 2-18F-FDG PET/CT was visually positive for 45 primary tumors (P = 0.002). Furthermore, subgroup analysis showed that 68Ga-LNC1007 PET/CT was superior to 2-18F-FDG PET/CT in diagnosing renal cell carcinomas and hepatocellular carcinomas. For metastatic tumors, 68Ga-LNC1007 PET/CT revealed more PET-positive lesions and higher SUVmax for skeletal metastases and peritoneal metastases compared with 2-18F-FDG. The SUVmax and tumor-to-background ratio of primary tumors on 68Ga-LNC1007 PET/CT were much higher than those on 68Ga-FAPI-02 PET/CT, the same was also observed for metastatic tumors. Immunohistochemical results showed that the SUVmean quantified from 68Ga-LNC1007 PET was correlated with FAP expression level (r = 0.564, P = 0.005). Conclusions 68Ga-LNC1007 is a promising new diagnostic PET tracer for imaging of various kinds of malignant lesions. It may be a better alternative to 2-18F-FDG for diagnosing renal cell carcinoma, hepatocellular carcinoma, skeletal metastases, and peritoneal metastases.