Feasibility of [68Ga]Ga-FAPI-46 PET/CT for detection of nodal and hematogenous spread in high-grade urothelial carcinoma

• DOI: 10.1007/s00259-022-05761-5
• Publication Date: 2022-03-25T00:03:16Z
• Authors: Lena M. Unterrainer; Simon Lindner; Lennert Eismann; Jozefina Casuscelli; Franz-Josef Gilde...; Vinh Ngoc Bui; Nathalie L. Albert; Adrien Holzgreve; Leonie Beyer; Andrei Todica; Matthias Brendel; Clemens C. Cyran; Alexander Karl; Christian G. Stief; Stephan T. Ledderose; Marcus Unterrainer; Peter Bartenstein; Vera Wenter; Alexander Kretschmer
• Keywords: PET-CT; Standardized uptake value; Primary tumor

[68Ga]Ga-FAPI-46 is a novel positron emission tomography (PET) ligand that targets fibroblast activation protein (FAP) expression as FAP inhibitor (FAPI) and could already show promising results in several tumor entities. It be demonstrated an increased correlates with aggressivity urothelial carcinoma (UC). Given the limited value of [18F]FDG UC, add diagnostic information staging response assessment UC. We present first data PET imaging pilot cohort UC patients evaluating uptake characteristics metastases primary tumors.Fifteen prior to or after local treatment underwent PET/CT for detection metastatic spread. compared biodistribution non-affected organs lesions by standard measurements (SUVmean SUVmax). Additionally, sites on were its morphological correlate contrast-enhanced computed (CT).Overall, 64 detected and/or CT. The highest intensity was noted at site (SUVmax 20.8 (range, 8.1-27.8)) followed lymph node 10.6 4.7-29.1)). In 4/15 (26.7%) there [68Ga]Ga-FAPI-46-positive missed routine CT imaging. On other hand, 2/15 had suspicious prominent bipulmonary nodules well pelvic nodes previously rated spread CT, but without FAPI expression; here histopathology excluded malignancy.[68Ga]Ga-FAPI-46 shows distinctly elevated lesions. Therefore, tracer has potential new biomarker patients, might improve alone. These findings highly emphasize larger studies investigating patients.