Denosumab是一种单克隆抗体，用于在骨巨细胞瘤（GCTB）中进行新辅助治疗，以促进手术；或者在手术并发高发病率的轴向肿瘤中进行长期治疗。治疗效果出现的时间间隔尚不清楚，监测工具有限，使得药物剂量的最佳调节变得复杂。我们评估了GCTB在denosumab治疗期间DCE-MRI衍生的时间强度曲线（TIC）血流灌注特征的变化，并评估了治疗效果对肿瘤灌注的持续时间。在单个中心进行了回顾性研究，纳入了在denosumab治疗前（t = 0）和治疗后的3个月（t = 3）、6个月（t = 6）或12个月（t = 12）进行动态对比增强（DCE）MRI的GCTB患者。在视觉上最强的增强部位放置感兴趣区域，并创建TIC曲线。计算增强时间（TTE），入流速率（WIR），最大相对增强（MRE）和曲线下面积（AUC）。使用Wilcoxon符号秩检验计算灌注特征的差异。所有24名患者在开始denosumab治疗后DCE-MRI上出现了灌注减少的情况。TTE在t = 0和t = 3之间增加（p < 0.001）。WIR，MRE和AUC在t = 0和t = 3之间减少（p < 0.001，p = 0.01和p = 0.02，分别）。在t = 3和t = 6或t = 6和t = 12之间未发现特征上的显著差异。在初发与复发病例或轴向与附肢肿瘤之间也没有发现显著的灌注差异。与基线相比，GCTB在denosumab治疗后3个月内MRI灌注发生了明显变化。在治疗的3个月和6个月，以及6个月与12个月之间没有进一步的显著变化。这些发现表明，在3个月后已经可能需要评估治疗反应，并考虑使用较低剂量的denosumab进行维持治疗。在长期应用denosumab的情况下，通过监测DCE-MRI上肿瘤特征的变化，可能有助于实现药物剂量的最佳调节，从而减少副作用。版权所有© 2023 作者。由Elsevier B.V.出版。保留所有权利。

Denosumab is a monoclonal antibody used neo-adjuvantly in giant cell tumor of bone (GCTB) to facilitate surgery, or long term for axial tumors where surgery comes with high morbidity. Time intervals for treatment effects to occur are unclear and monitoring tools are limited, complicating optimal drug dose titration. We assessed changes in time intensity curve (TIC) - derived perfusion features on DCE-MRI in GCTB during denosumab treatment and evaluated the duration of treatment effects on tumor perfusion.Patients with GCTB who underwent dynamic contrast enhanced (DCE) MRI before (t = 0) and after 3 (t = 3), 6 (t = 6) or 12 (t = 12) months of denosumab treatment were retrospectively included in a single center. Regions of interest were placed on tumor compartments with visually most intense enhancement and TICs were created. Time-to-enhancement (TTE), wash-in rate (WIR), maximal relative enhancement (MRE), and area-under-the-curve (AUC) were calculated. Differences in perfusion features were calculated with the Wilcoxon signed-rank test.In all 24 patients decreased perfusion on DCE-MRI after start of denosumab treatment was seen. TTE increased between t = 0 and t = 3 (p < 0.001). WIR, MRE and AUC decreased between t = 0 and t = 3 (p < 0.001, p = 0.01 and p = 0.02, respectively). No significant differences in features were found between t = 3 and t = 6 or t = 6 and t = 12. No significant perfusion differences in primary versus recurrent, or axial versus appendicular tumors, were found.MRI perfusion significantly changed in GCTB within 3 months of denosumab treatment compared to baseline. No further significant change occurred between 3 and 6, and 6 and 12 months of treatment. These findings suggest that evaluation of treatment response and subsequent consideration of maintenance with lower doses of denosumab, may already be indicated after 3 months. In cases where long term denosumab is the preferred therapy, monitoring change in tumor characteristics on DCE-MRI may aid optimal drug dose titration, minimizing side effects.Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.