The molar dose of FAPI administered impacts on the FAP-targeted PET imaging and therapy in mouse syngeneic tumor models

• DOI: 10.1007/s00259-025-07071-y
• Publication Date: 2025-01-11T04:18:00Z
• Authors: Luoxia Liu; Yifan Shi; Shujie He; Jingfei Yang; Shuang Song; Dongdong Wang; Ziqiang Wang; Huimin Zhou; Xiaoyun Deng; Sijuan Zou; Yuankai Zhu; Bo Yu; Xiaohua Zhu
• Keywords: Imaging biomarker

Since fibroblast activation protein (FAP), one predominant biomarker of cancer associated fibroblasts (CAFs), is highly expressed in the tumor stroma various epidermal-derived cancers, targeting FAP for diagnosis and treatment has shown substantial potentials both preclinical clinical studies. However, settings, tumor-bearing mice exhibit relatively low absolute expression levels, leading to challenges acquiring high-quality PET images using radiolabeled ligands (FAPIs) with molar activity, because which a saturation effect imaging prone happen. Moreover, how exactly dose FAPI administered mouse influences targeted radiotherapy remains unclear now. Therefore, this study aims investigate impacts on FAP-targeted syngeneic models. [68Ga]Ga-FAPI-04 doses FAPI-04 was wild-type 4T1 mice, followed by static imaging. Sigmoidal curves were generated analyze correlation between standard uptake value (SUV) FAPI-04. Similarly, [177Lu]Lu-DOTAGA.(SA.FAPi)2 consistent radioactivity but containing different moles DOTAGA.(SA.FAPi)2 injected into assess therapeutic effect. also applied models PET/CT A gradient blocking observed increasing treatment, outcomes. characterize murine derived The [68Ga]Ga/[177Lu]Lu-FAPI had impact therapy To acquire enhanced reliability reproducibility situation, it critical carefully consider radiotracer when applying radiotherapy.