Background: The decreased perfusion of osteosarcoma in dynamic contrast-enhanced (DCE) MRI, reflecting a good histological response to neoadjuvant chemotherapy, has been described. Purpose: In this study, we aim to explore the potential of the relative wash-in rate as a prognostic factor for event-free survival (EFS). Methods: Skeletal high-grade osteosarcoma patients, treated in two tertiary referral centers between 2005 and 2022, were retrospectively included. The relative wash-in rate (rWIR) was determined with DCE-MRI before, after, or during the second cycle of chemotherapy (pre-resection). A previously determined cut-off was used to categorize patients, where rWIR < 2.3 was considered poor and rWIR ≥ 2.3 a good radiological response. EFS was defined as the time from resection to the first event: local recurrence, new metastases, or tumor-related death. EFS was estimated using Kaplan–Meier’s methodology. Multivariate Cox proportional hazard model was used to estimate the effect of histological response and rWIR on EFS, adjusted for traditional prognostic factors. Results: Eighty-two patients (median age: 17 years; IQR: 14–28) were included. The median follow-up duration was 11.8 years (95% CI: 11.0–12.7). During follow-up, 33 events occurred. Poor histological response was not significantly associated with EFS (HR: 1.8; 95% CI: 0.9–3.8), whereas a poor radiological response was associated with a worse EFS (HR: 2.4; 95% CI: 1.1–5.0). In a subpopulation without initial metastases, the binary assessment of rWIR approached statistical significance (HR: 2.3; 95% CI: 1.0–5.2), whereas its continuous evaluation demonstrated a significant association between higher rWIR and improved EFS (HR: 0.7; 95% CI: 0.5–0.9), underlining the effect of response to chemotherapy. The 2- and 5-year EFS for patients with a rWIR ≥ 2.3 were 85% and 75% versus 55% and 50% for patients with a rWIR < 2.3. Conclusion: The predicted poor chemo response with MRI (rWIR < 2.3) is associated with shorter EFS even when adjusted for known clinical covariates and shows similar results to histological response evaluation. rWIR is a potential tool for future response-based individualized healthcare in osteosarcoma patients before surgical resection.
背景：动态对比增强磁共振成像（DCE-MRI）中骨肉瘤灌注降低已被证实可反映新辅助化疗的良好组织学反应。目的：本研究旨在探讨相对流入率作为无事件生存期（EFS）预后因素的潜力。方法：回顾性纳入2005年至2022年间在两个三级转诊中心接受治疗的高级别骨肉瘤患者。在化疗前、化疗后或第二周期化疗期间（术前）通过DCE-MRI测定相对流入率（rWIR）。采用预先设定的临界值对患者进行分类，其中rWIR < 2.3视为影像学反应不良，rWIR ≥ 2.3视为影像学反应良好。EFS定义为从手术切除至首次事件（局部复发、新发转移或肿瘤相关死亡）的时间。采用Kaplan-Meier法评估EFS，并运用多变量Cox比例风险模型分析组织学反应和rWIR对EFS的影响，同时校正传统预后因素。结果：共纳入82例患者（中位年龄17岁；四分位距14-28岁）。中位随访时间为11.8年（95%置信区间：11.0-12.7）。随访期间共发生33起事件。组织学反应不良与EFS无显著相关性（风险比：1.8；95%置信区间：0.9-3.8），而影像学反应不良与较差的EFS显著相关（风险比：2.4；95%置信区间：1.1-5.0）。在无初始转移的亚组中，rWIR的二元评估接近统计学显著性（风险比：2.3；95%置信区间：1.0-5.2），而其连续评估显示较高的rWIR与改善的EFS存在显著关联（风险比：0.7；95%置信区间：0.5-0.9），这突显了化疗反应的影响。rWIR ≥ 2.3患者的2年和5年EFS分别为85%和75%，而rWIR < 2.3患者分别为55%和50%。结论：即使在调整已知临床协变量后，MRI预测的化疗反应不良（rWIR < 2.3）仍与较短的EFS相关，且结果与组织学反应评估相似。rWIR有望成为骨肉瘤患者手术切除前实施未来个体化反应导向治疗的潜在工具。
肿瘤(癌症)患者之家