68Ga-FAPI PET/CT Imaging

Abstract

68Ga-FAPI has been introduced recently in many nuclear medicine centers. Many pitfalls have been discussed previously. However, not all pitfalls are currently addressed in the literature. To our knowledge, this is the first reported case to address nonspecific 68Ga-FAPI expression at anorectal sphincter. A 69-year-old woman was diagnosed with intrahepatic cholangiocarcinoma. A 68Ga-FAPI scan was performed after diagnostic workup and chemoradiotherapy. In addition to 68Ga-FAPI–avid lesion at primary site, several nononcological ancillary findings have been observed. This includes unaddressed 68Ga-FAPI–avid focus within anorectal sphincter. Moreover, the same noteworthy findings were observed in the musculoskeletal and gynecological systems.

Superiority of 18F-FAPI-42 PET/CT in the detection of primary tumor and management of appendiceal neoplasm to 18F-FDG PET/CT and CE-CT

“…Radionuclide labelled, fibroblast-activated, protein inhibitors (FAPI), such as 68 Ga-FAPI, have been developed as PET tracers and show superiority to 18 F-FDG in imaging various cancers [ 13 – 15 ], especially in gastric cancer, pancreaticobiliary neoplasms and some rare tumors [ 16 – 18 ], although FAPI uptake can occur in non-oncologic conditions [ 19 , 20 ]. It was found that gastrointestinal tumors, even those containing mucus or signet ring cell carcinoma, had high FAPI uptake and these lesions could be depicted clearly [ 14 , 21 ].…”

Fibroblast Activation Protein Inhibitor Theranostics: A Huge Opportunity with its Fair Share of Oncological Pitfalls

“…14 Studies have also indicated that the FAPI may have the ability to distinguish between malignant and benign conditions based on uptake patterns, and tracer uptake kinetics. 15 Recent research has highlighted the potential of the FAPI for noninvasive assessment of various systemic diseases, including immunoglobulin G4-related diseases, rheumatoid arthritis, myocarditis, and pancreatitis. 8…”

“…10 Despite their potential benefits, FAPI imaging faces inherent challenges and limitations. 11 Diagnostically, the FAPI has been found to have suboptimal specificity for detecting malignant tumors. The interindividual variability underscores the varying levels of FAP expression in different diseases and even within the same disease.…”