Molecular imaging of muscle-invasive bladder cancer (MBC) is restricted to its locoregional and distant metastases, since most radiopharmaceuticals have a urinary excretion that limits the visualization of the primary tumor. ⁶⁴CuCl_2, a positron-emitting radiotracer with nearly exclusive biliary elimination, could be well suited to exploring urinary tract neoplasms. In this study, we evaluated the feasibility of ⁶⁴CuCl₂-based staging of patients with MBC; furthermore, we compared the diagnostic capability of this method with those of the current gold standards, that is, contrast-enhanced CT (ceCT) and ¹⁸F-FDG PET/CT. Methods: We prospectively enrolled patients referred to our institution for pathology-confirmed MBC staging/restaging between September 2021 and January 2023. All patients underwent ceCT, ¹⁸F-FDG, and ⁶⁴CuCl₂ PET/CT within 2 wk. Patient-based analysis and lesion-based analysis were performed for all of the potentially affected districts (overall, bladder wall, lymph nodes, skeleton, liver, lung, and pelvic soft tissue). Results: Forty-two patients (9 women) were enrolled. Thirty-six (86%) had evidence of disease, with a total of 353 disease sites. On patient-based analysis, ceCT and ⁶⁴CuCl₂ PET/CT showed higher sensitivity than ¹⁸F-FDG PET/CT in detecting the primary tumor (P < 0.001); moreover, ⁶⁴CuCl₂ PET/CT was slightly more sensitive than ¹⁸F-FDG PET/CT in disclosing soft-tissue lesions (P < 0.05). Both PET methods were more specific and accurate than ceCT in classifying nodal lesions (P < 0.05). On lesion-based analysis, ⁶⁴CuCl₂ PET/CT outperformed ¹⁸F-FDG PET/CT and ceCT in detecting disease localizations overall (P < 0.001), in the lymph nodes (P < 0.01), in the skeleton (P < 0.001), and in the soft tissue (P < 0.05). Conclusion: ⁶⁴CuCl₂ PET/CT appears to be a sensitive modality for staging/restaging of MBC and might represent a “one-stop shop” diagnostic method in these scenarios.

肌层浸润性膀胱癌 (MBC) 的分子成像仅限于其局部和远处转移，因为大多数放射性药物具有尿液排泄，限制了原发肿瘤的可视化。 ⁶⁴ CuCl ₂是一种几乎具有胆汁消除功能的正电子发射放射性示踪剂，非常适合探索尿路肿瘤。在本研究中，我们评估了基于⁶⁴ CuCl ₂的 MBC 患者分期的可行性；此外，我们将该方法的诊断能力与当前的金标准，即增强CT（ceCT）和¹⁸ F-FDG PET/CT 进行了比较。方法：我们前瞻性地招募了2021年9月至2023年1月期间转诊至我们机构进行病理证实的MBC分期/再分期的患者。所有患者均在2周内接受了ceCT、 ¹⁸ F-FDG和⁶⁴ CuCl ₂ PET/CT。对所有可能受影响的区域（总体、膀胱壁、淋巴结、骨骼、肝脏、肺和盆腔软组织）进行了基于患者的分析和基于病变的分析。结果： 42 名患者（9 名女性）入组。 36 个 (86%) 有疾病证据，总共 353 个疾病部位。在基于患者的分析中，ceCT和⁶⁴ CuCl ₂ PET/CT 在检测原发肿瘤方面表现出比¹⁸ F-FDG PET/CT 更高的敏感性（ P < 0.001）；此外， ⁶⁴ CuCl ₂ PET/CT 在显示软组织病变方面比¹⁸ F-FDG PET/CT 稍敏感（ P < 0.05）。 两种 PET 方法在淋巴结病变分类方面均比 ceCT 更特异、更准确 ( P < 0.05)。在基于病灶的分析中， ⁶⁴ CuCl ₂ PET/CT 在检测疾病定位总体上（ P < 0.001）、淋巴结（ P < 0.01）、骨骼（ P ）方面优于¹⁸ F-FDG PET/CT 和 ceCT < 0.001) 和软组织中 ( P < 0.05)。结论： ⁶⁴ CuCl ₂ PET/CT 似乎是 MBC 分期/再分期的敏感方式，并且可能代表这些情况下的“一站式”诊断方法。