Lütje Susanne, Schäfer Laura, Altunay Betül, Hertel Fabian, Morgenroth Agnieszka, Mottaghy Felix M
Department of Nuclear Medicine, RWTH Aachen University Hospital, Pauwelsstraße 30, Aachen, 52074, Germany.
Center for Integrated Oncology (CIO), University Hospital RWTH Aachen, 52074, Aachen, Germany.
Eur J Nucl Med Mol Imaging. 2025 Jul 15. doi: 10.1007/s00259-025-07439-0.
T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is a novel immune checkpoint receptor implicated in tumor immune evasion. Non-invasive imaging of TIGIT expression holds potential for improving patient selection and monitoring in cancer immunotherapy. This systematic review aims to evaluate recent advancements in radiotracer development for non-invasive visualization of TIGIT.
A comprehensive literature search was conducted up to February 2025 using databases including PubMed and Web of Science. The search terms "TIGIT imaging", "TIGIT PET", "TIGIT SPECT", and "TIGIT visualization" were used, focusing on those reporting on the development, characterization, or application of immuno-PET tracers targeting TIGIT expression. Both preclinical and clinical studies were reviewed.
Six studies met the inclusion criteria, exploring tracers targeting TIGIT expression on immune cells. These studies have focused on the development of TIGIT-targeted imaging agents, including radiolabeled antibodies, peptides, and nanobodies for positron emission tomography (PET) and single-photon emission tomography (SPECT) imaging. These agents demonstrated high specificity and enabled visualization of TIGIT expression in preclinical models and one exploratory clinical study.
Novel radiotracers for non-invasive imaging of TIGIT show potential for enhancing personalized cancer immunotherapy. TIGIT-targeted imaging agents allow for the visualization and quantification of TIGIT expression in tumors/tumor microenvironment, which in future might contribute to better patient selection and treatment monitoring. Further research and clinical validation are necessary to optimize these imaging techniques for routine clinical application.
T细胞免疫球蛋白和基于免疫受体酪氨酸的抑制基序结构域（TIGIT）是一种与肿瘤免疫逃逸相关的新型免疫检查点受体。TIGIT表达的非侵入性成像在改善癌症免疫治疗中的患者选择和监测方面具有潜力。本系统评价旨在评估用于TIGIT非侵入性可视化的放射性示踪剂开发的最新进展。
截至2025年2月，使用包括PubMed和Web of Science在内的数据库进行了全面的文献检索。使用了“TIGIT成像”、“TIGIT正电子发射断层扫描（PET）”、“TIGIT单光子发射计算机断层扫描（SPECT）”和“TIGIT可视化”等检索词，重点关注那些报道靶向TIGIT表达的免疫PET示踪剂的开发、表征或应用的研究。对临床前和临床研究均进行了综述。
六项研究符合纳入标准，探索了靶向免疫细胞上TIGIT表达的示踪剂。这些研究集中在TIGIT靶向成像剂的开发上，包括用于正电子发射断层扫描（PET）和单光子发射计算机断层扫描（SPECT）成像的放射性标记抗体、肽和纳米抗体。这些试剂显示出高特异性，并能够在临床前模型和一项探索性临床研究中实现TIGIT表达的可视化。
用于TIGIT非侵入性成像的新型放射性示踪剂显示出增强个性化癌症免疫治疗的潜力。TIGIT靶向成像剂能够实现肿瘤/肿瘤微环境中TIGIT表达的可视化和定量，这在未来可能有助于更好地进行患者选择和治疗监测。为将这些成像技术优化用于常规临床应用，还需要进一步的研究和临床验证。
