针对0.35T MR-Linac的多中心扩散权重MRI验证
Siamak Nejad-Davarani1, Natalia Lutsik1, Kathryn Mittauer2
1Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
概括
表面扩散系数 (ADC) 测量在多个低场MR-linacs中是可重复和可重复的,这证实了其适应性放射治疗试验的可靠性. 这支持在多中心研究中使用ADC作为生物标志物.
科学领域:
- 医学物理 医学物理
- 放射治疗技术 放射治疗技术
- 生物标志物开发 生物标志物开发
背景情况:
- 磁共振线性加速器 (MR-linac) 可用于适应性放射治疗的日常成像.
- 从扩散权重成像 (DWI) 获得的明显扩散系数 (ADC) 是瘤细胞性和治疗反应的定量生物标志物.
- 验证ADC的重复性和可重复性对于使用低场MR-linacs的多中心试验至关重要.
研究的目的:
- 评估ADC测量在低场MR-linacs上的可重复性和可重复性.
- 为了评估不同的b值集和线圈对ADC可变性的影响.
- 为了确定门架角度引起的扭曲对ADC准确性的影响.
主要方法:
- 基于回声平面成像 (EPI) 的DWI在四个机构的幻体上进行.
- 使用了两个b值集 ([0,30,60,90,120,150,180,200,500,1000]和[0,500,1000]s/mm2) 的结果.
- 通过在一个部位进行四次扫描来评估可重复性;使用大脑和干线圈在不同部位进行可重复性.
主要成果:
- 对ADC的变化系数 (COV) 较低,在不同的b值集和线圈中从0.196%到6.902%不等.
- 多个地点的COV也很低,从0.267%到5.357%不等.
- 格兰特角扭曲增加了三个b值的正常化根平均平方误差 (nRMSE) 到10.767%和十个b值的6.236%.
结论:
- 在低场MR-linacs上,ADC测量显示出出色的重复性和可重复性.
- 这些发现支持使用ADC作为多中心适应性放射治疗试验中可靠的生物标志物.
- 在线圈和b值集之间的低可变性提高了对ADC临床实用性的信心.
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