Accurate whole-body staging following biochemical relapse in prostate cancer is vital in determining the optimum disease management. Current imaging guidelines recommend various imaging platforms such as computed tomography (CT), Technetium 99 m (99mTc) bone scan and 18F-choline and recently 68Ga-PSMA positron emission tomography (PET) for the evaluation of the extent of disease. Such approach requires multiple hospital attendances and can be time and resource intensive. Recently, whole-body magnetic resonance imaging (WB-MRI) has been used in a single visit scanning session for several malignancies, including prostate cancer, with promising results, providing similar accuracy compared to the combined conventional imaging techniques. The LOCATE trial aims to investigate the application of WB-MRI for re-staging of patients with biochemical relapse (BCR) following external beam radiotherapy and brachytherapy in patients with prostate cancer. The LOCATE trial is a prospective cohort, multi-centre, non-randomised, diagnostic accuracy study comparing WB-MRI and conventional imaging. Eligible patients will undergo WB-MRI in addition to conventional imaging investigations at the time of BCR and will be asked to attend a second WB-MRI exam, 12-months following the initial scan. WB-MRI results will be compared to an enhanced reference standard comprising all the initial, follow-up imaging and non-imaging investigations. The diagnostic performance (sensitivity and specificity analysis) of WB-MRI for re-staging of BCR will be investigated against the enhanced reference standard on a per-patient basis. An economic analysis of WB-MRI compared to conventional imaging pathways will be performed to inform the cost-effectiveness of the WB-MRI imaging pathway. Additionally, an exploratory sub-study will be performed on blood samples and exosome-derived human epidermal growth factor receptor (HER) dimer measurements will be taken to investigate its significance in this cohort. The LOCATE trial will compare WB-MRI versus the conventional imaging pathway including its cost-effectiveness, therefore informing the most accurate and efficient imaging pathway. LOCATE trial was registered on ClinicalTrial.gov on 18th of October 2016 with registration reference number NCT02935816.

中文翻译：

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使用先进的成像技术定位隐匿性前列腺癌转移（LOCATE 试验）：一项前瞻性队列、观察性诊断准确性试验，研究全身磁共振成像在放射性复发前列腺癌中的应用

前列腺癌生化复发后准确的全身分期对于确定最佳疾病管理至关重要。当前的成像指南推荐了各种成像平台，例如计算机断层扫描 (CT)、锝 99 m (99mTc) 骨扫描和 18F-胆碱以及最近的 68Ga-PSMA 正电子发射断层扫描 (PET)，用于评估疾病的程度。这种方法需要多次到医院就诊并且可能是时间和资源密集型的。最近，全身磁共振成像 (WB-MRI) 已被用于包括前列腺癌在内的多种恶性肿瘤的单次访问扫描会话，结果很有希望，与组合的传统成像技术相比，提供了相似的准确性。LOCATE 试验旨在研究 WB-MRI 在前列腺癌患者外照射放疗和近距离放疗后生化复发 (BCR) 患者重新分期中的应用。LOCATE 试验是一项前瞻性队列、多中心、非随机、诊断准确性研究，比较 WB-MRI 和传统成像。符合条件的患者将在 BCR 时接受 WB-MRI 以及常规成像检查，并将被要求在初次扫描后 12 个月参加第二次 WB-MRI 检查。WB-MRI 结果将与包含所有初始、后续成像和非成像研究的增强参考标准进行比较。WB-MRI 对 BCR 重新分期的诊断性能（敏感性和特异性分析）将在每个患者的基础上根据增强的参考标准进行研究。将进行 WB-MRI 与传统成像途径相比的经济分析，以告知 WB-MRI 成像途径的成本效益。此外，还将对血液样本进行探索性子研究，并将进行外泌体衍生的人表皮生长因子受体 (HER) 二聚体测量，以研究其在该队列中的重要性。LOCATE 试验将比较 WB-MRI 与传统成像途径，包括其成本效益，从而为最准确和有效的成像途径提供信息。LOCATE 试验于 2016 年 10 月 18 日在 ClinicalTrial.gov 上注册，注册参考号为 NCT02935816。