Background: The role of molecular imaging in urothelial cancer is less defined than other cancers, and its utility remains controversial due to limitations such as high urinary tracer excretion, complicating primary tumour assessment in the bladder and upper urinary tract. This review explores the current landscape of PET imaging in the clinical management of urothelial cancer, with a special emphasis on potential future advancements including emerging novel non-18F FDG PET agents, PET radiopharmaceuticals, and PET-MRI applications.Methods: We conducted a comprehensive literature search in the PubMed database, using keywords such as “PET”, “PET-CT”, “PET-MRI”, “FDG PET”, “Urothelial Cancer”, and “Theranostics”. Studies were screened for relevance, focusing on imaging modalities and advances in PET tracers for urothelial carcinoma. Non-English language, off-topic papers, and case reports were excluded, resulting in 80 articles being selected for discussion.Results:18F FDG PET-CT has demonstrated superior sensitivity over conventional imaging, such as contrast-enhanced CT and MRI, for detecting lymph node metastasis and distant disease. Despite these advantages, FDG PET-CT is limited for T-staging of primary urothelial tumours due to high urinary excretion of the tracer. Emerging evidence supports the role of PETC-CT in assessing response to neoadjuvant chemotherapy and in identifying recurrence, with a high diagnostic accuracy reported in several studies. Novel PET tracers, such as68Ga-labelled FAPI, have shown promising results in targeting cancer-associated fibroblasts, providing higher tumour-to-background ratios and detecting lesions missed by traditional imaging. Antibody-based PET tracers, like those targeting Nectin-4, CAIX, and uPAR, are under investigation for their diagnostic and theranostic potential, and initial studies indicate that these agents may offer advantages over conventional imaging and FDG PET.Conclusions:Molecular imaging is a rapidly evolving field in urothelial cancer, offering improved diagnostic and prognostic capabilities. While18F FDG PET-CT has shown utility in staging, further prospective research is needed to establish and refine standardised protocols and validate new tracers. Advances in theranostics and precision imaging may revolutionise urothelial cancer management, enhancing the ability to tailor treatments and improve patient outcomes.
背景：与其他癌症相比，分子影像学在尿路上皮癌中的作用尚不明确，且由于示踪剂经尿液高排泄等局限性，其在膀胱及上尿路原发肿瘤评估中的应用仍存在争议。本综述探讨了PET影像在尿路上皮癌临床管理中的现状，并特别关注了未来潜在的发展方向，包括新兴的非¹⁸F-FDG PET示踪剂、PET放射性药物以及PET-MRI的应用。 方法：我们在PubMed数据库中进行了全面的文献检索，使用的关键词包括“PET”、“PET-CT”、“PET-MRI”、“FDG PET”、“尿路上皮癌”和“诊疗一体化”。筛选相关研究时，重点关注影像学模式及尿路上皮癌PET示踪剂的进展。排除了非英语文献、主题不符的论文及病例报告，最终选取80篇文章进行讨论。 结果：¹⁸F-FDG PET-CT在检测淋巴结转移和远处转移方面，显示出优于传统影像学（如增强CT和MRI）的敏感性。尽管有这些优势，但由于示踪剂经尿液高排泄，FDG PET-CT在原发尿路上皮肿瘤的T分期方面存在局限。新出现的证据支持PET-CT在评估新辅助化疗反应和识别复发中的作用，多项研究报告了其较高的诊断准确性。新型PET示踪剂，如⁶⁸Ga标记的FAPI，在靶向癌症相关成纤维细胞方面显示出良好前景，提供了更高的肿瘤-本底比值，并能检测到传统影像遗漏的病灶。基于抗体的PET示踪剂，如靶向Nectin-4、CAIX和uPAR的示踪剂，其诊断和诊疗一体化潜力正在研究中，初步研究表明这些药物可能优于传统影像和FDG PET。 结论：分子影像学是尿路上皮癌领域一个快速发展的方向，提供了更好的诊断和预后评估能力。虽然¹⁸F-FDG PET-CT在分期中已显示出效用，但仍需进一步的前瞻性研究来建立和完善标准化方案，并验证新型示踪剂。诊疗一体化和精准影像学的进展可能彻底改变尿路上皮癌的管理，提升个体化治疗的能力并改善患者预后。
Nuclear Medicine and Molecular Imaging in Urothelial Cancer: Current Status and Future Directions
肿瘤(癌症)患者之家