Department of Radiation Oncology, University of Iowa, Iowa City, Iowa.
Department of Radiology, University of Iowa, Iowa City, Iowa.
Radiat Res. 2021 Mar 1;195(3):230-234. doi: 10.1667/RADE-20-00199.1.
MR-linac technology enhances the precision of therapeutic radiation by clarifying the tumor-normal tissue interface and provides the potential for adaptive treatment planning. Accurate delineation of tumors on diagnostic magnetic resonance imaging (MRI) frequently requires gadolinium-based contrast agents (GBCAs). Despite generally being considered safe, previous literature suggests that GBCAs are capable of contrast-induced acute kidney injury (AKI). It is unclear if the risk for AKI is enhanced when GBCAs are administered concurrently with ionizing radiotherapy. During irradiation, gadolinium may be liberated from its chelator which may induce AKI. The goal of this work was to determine if radiation combined with GBCAs increased the incidence of AKI. Using a preclinical MRI-guided irradiation system, where MRI acquisitions and radiation delivery are performed in rapid succession, tumor-bearing mice with normal kidney function were injected with GBCA and treated with 2, 8 or 18 Gy irradiation. Renal function was assessed on days three and seven postirradiation to assess for AKI. No clinically relevant changes in blood urea nitrogen and creatinine were observed in any combination of GBCA and radiation dose. From these data, we conclude that GBCA in combination with radiation does not increase the risk for AKI in mice. Additional investigation of multiple doses of GBCA administered concurrently with irradiation is warranted to evaluate the risk of chronic kidney injury.
磁共振直线加速器技术通过明确肿瘤-正常组织界面来提高治疗性辐射的精度，并为适应性治疗计划提供了潜力。在诊断磁共振成像（MRI）上准确勾画肿瘤通常需要使用基于钆的造影剂（GBCA）。尽管通常被认为是安全的，但之前的文献表明 GBCA 有引发造影剂诱导的急性肾损伤（AKI）的能力。目前尚不清楚当 GBCA 与电离放疗同时给药时，AKI 的风险是否会增加。在照射过程中，钆可能会从其螯合剂中释放出来，从而导致 AKI。这项工作的目的是确定辐射联合 GBCA 是否会增加 AKI 的发生率。使用临床前 MRI 引导的放射系统，其中 MRI 采集和放射治疗快速连续进行，具有正常肾功能的荷瘤小鼠被注射 GBCA 并接受 2、8 或 18 Gy 的照射。在照射后第 3 天和第 7 天评估肾功能以评估 AKI。在任何 GBCA 和放射剂量组合中，均未观察到血尿素氮和肌酐的临床相关变化。根据这些数据，我们得出结论，GBCA 联合放射治疗不会增加小鼠 AKI 的风险。需要进一步研究同时给予多种剂量的 GBCA 与放射治疗，以评估慢性肾损伤的风险。
