Abstract：
Radiolabeled FAPI (fibroblast activation protein inhibitors) recently gained attention as widely applicable imaging and potential therapeutic compounds targeting CAF (cancer-associated fibroblasts) or DAF (disease-associated fibroblasts in benign disorders). Moreover, the use of FAPI has distinct advantages compared to FDG (e.g., increased sensitivity in regions with high glucose metabolism, no need for fasting, and rapid imaging). In this study, we wanted to evaluate the radiochemical synthesis and the clinical properties of the new CAF-targeting tracer [68Ga]Ga-DATA5m.SA.FAPi. The compound consists of a (radio)chemically easy to use hybrid chelate DATA.SA, which can be labeled at low temperatures, making it an interesting molecule for \'instant kit-type\' labeling, and a squaric acid moiety that provides distinct advantages for synthesis and radiolabeling. Our work demonstrates that automatic synthesis of the FAP inhibitor [68Ga]Ga-DATA5m.SA.FAPi is feasible and reproducible, providing convenient access to this new hybrid chelator-based tracer. Our studies demonstrated the diagnostic usability of [68Ga]Ga-DATA5m.SA.FAPi for the unambiguous detection of cancer-associated fibroblasts of various carcinomas and their metastases (NSCLC, liposarcoma, parotid tumors, prostate cancer, and pancreas adenocarcinoma), while physiological uptake in brain, liver, intestine, bone, and lungs was very low.
摘要：
放射性标记的FAPI(成纤维细胞活化蛋白抑制剂)最近作为靶向CAF(癌症相关成纤维细胞)或DAF(良性病症中的疾病相关成纤维细胞)的广泛适用的成像和潜在的治疗化合物而受到关注。此外，与FDG相比，使用FAPI具有明显的优势(例如，高葡萄糖代谢区域的敏感性增加，不需要禁食，和快速成像）。在这项研究中,我们想评估新的CAF靶向示踪剂[68Ga]Ga-DATA5m的放射化学合成和临床特性。SA.FAPi.该化合物由化学上易于使用的杂合螯合物DATA组成。SA,可以在低温下贴上标签，使其成为“即时试剂盒型”标签的有趣分子，和为合成和放射性标记提供独特优势的方酸部分。我们的工作证明了FAP抑制剂[68Ga]Ga-DATA5m的自动合成。SA.FAPi是可行的和可重复的，提供方便的访问这种新的混合螯合剂为基础的示踪剂。我们的研究证明了[68Ga]Ga-DATA5m的诊断可用性。SA.FAPi用于明确检测各种癌及其转移的癌相关成纤维细胞（NSCLC，脂肪肉瘤,腮腺肿瘤,前列腺癌,和胰腺腺癌），而大脑的生理摄取，肝脏,肠,骨头,肺很低。
