RT Journal Article SR Electronic T1 68Ga-FAPI-04 PET provides better diagnostic imaging for malignant colorectal carcinomas than 18F-FDG PET JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 2536 OP 2536 VO 63 IS supplement 2 A1 Shangguan, Chengfang YR 2022 UL http://jnm.snmjournals.org/content/63/supplement_2/2536.abstract AB 2536 Introduction: FDG high-uptake lesions indicate not only carcinoma but also benign lesions.The 68Ga-labelled FAPI was accumulated in various tumors. However, it's unclear about the capacity of FAPI-PET in identifying malignant tumors from benign leions.Methods: Clinical and histology dada of 209 18F-FDG-avid colorectal lesions were collected. An AOM/DSS-induced rat colorectal tumor model was established. A double PET/CT tracer of 68Ga-FAPI-04 and 18F-FDG was used in the clinical trial and rat colorectal tumor model. Immunohistochemistry staining, enteroscopy, and radioautography were performed in this study. Results: Eight out of 22 patients had 18F-FDG-avid colorectal lesions, but they were negative in 68Ga-FAP-04 PET imaging.   An inflammatory lesion did not interfere with 68Ga-FAPI PET imaging. 68Ga-FAPI PET imaging distinguishes neoplasia from inflammatory lesions in an AOM/DSS-induced rat colorectal tumor model, and FAPI accumulation gradually uncrease along with tumor progression. Moreover, the clinical study demonstrated that in all of 18F-FDG-avid colorectal lesions, only 20.5% (16 out of 78) of premalignant/benign lesions were weak FAP-positive. However, most cancer patients (85.1%, 80 out of 94) were FAP-positive, which further supported the above findings. Conclusions: The 68Ga-FAPI-04 PET distinguishes malignant tumors from inflammatory lesions by detecting FAP in a rat colorectal tumor model and the clinics, suggesting that 68Ga-FAPI-04 PET is a better diagnostic tool than 18F-FDG PET, at least to colorectal cancer patients.