Dynamic changes in the tumor-associated fibroblast activation protein (FAP) expression in tumors of different stages may be helpful for prognostic evaluation and treatment response monitoring, making this protein a promising surveillance biomarker for timely diagnosis of malignant tumors and effective planning of patient care. To prospectively verify the diagnostic efficacy value of the developed FAP tracers, [⁶⁸Ga]Ga-FAPtp and [⁶⁸Ga]Ga-Alb-FAPtp-01, dynamic/static positron emission tomography (PET)/computed tomography scans were acquired for tumor-targeting studies in vivo and in comparison with the well-established clinically used tracer [⁶⁸Ga]Ga-FAPI-04. The optimized rationally designed FAP-targeting PET tracer, [⁶⁸Ga]Ga-Alb-FAPtp-01, with albumin-binding capability demonstrated prominent tumor uptake over time. The mean standard uptake value (SUV) and the tumor/muscle (T/M) ratio were as high as 1.775 ± 0.179 SUV and T/M = 5.9, 1.533 ± 0.222 SUV and T/M = 6.7, and 1.425 ± 0.204 SUV and T/M = 9.5, respectively, at 1, 2, and 3 h. Its improved tumor uptake and pharmacokinetics suggest that the [⁶⁸Ga]Ga-Alb-FAPtp-01 tracer can noninvasively detect FAP activation in vivo, permitting a precise definition of its roles in tumors of different stages and yielding insights regarding FAP-targeted radiotherapeutic strategies at the molecular level.

中文翻译：

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用于胶质瘤 PET 成像的选择性肿瘤相关成纤维细胞活化蛋白示踪剂 [68Ga]Ga-Alb-FAPtp-01 的合理设计、药物调节和合成

不同阶段肿瘤中肿瘤相关成纤维细胞活化蛋白（FAP）表达的动态变化可能有助于预后评估和治疗反应监测，使该蛋白成为及时诊断恶性肿瘤和有效规划患者护理的有前景的监测生物标志物。为了前瞻性地验证开发的 FAP 示踪剂 [ ⁶⁸ Ga]Ga-FAPtp 和 [ ⁶⁸ Ga]Ga-Alb-FAPtp-01的诊断功效价值，获得了肿瘤的动态/静态正电子发射断层扫描 (PET)/计算机断层扫描扫描-体内靶向研究并与成熟的临床使用示踪剂 [ ⁶⁸ Ga]Ga-FAPI-04 进行比较。优化合理设计的 FAP 靶向 PET 示踪剂，[ ⁶⁸Ga]Ga-Alb-FAPtp-01 具有白蛋白结合能力，随着时间的推移显示出显着的肿瘤吸收。平均标准摄取值 (SUV) 和肿瘤/肌肉 (T/M) 比值高达 1.775 ± 0.179 SUV 和 T/M = 5.9、1.533 ± 0.222 SUV 和 T/M = 6.7 和 1.425 ± 0.204 SUV和 T/M = 9.5，分别在 1、2 和 3 小时。其改善的肿瘤吸收和药代动力学表明 [ ⁶⁸ Ga]Ga-Alb-FAPtp-01 示踪剂可以无创地检测体内FAP 激活，从而精确定义其在不同阶段肿瘤中的作用，并产生有关 FAP 靶向放疗策略的见解在分子水平。