三维硅基辐射变色剂量计在磁场存在下对光子辐照的剂量响应。

Jensen Morten B, Balling Peter, Doran Simon J, Petersen Jørgen B B, Wahlstedt Isak H, Muren Ludvig P

Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.

Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark.

Phys Imaging Radiat Oncol. 2020 Oct 19;16:81-84. doi: 10.1016/j.phro.2020.10.003. eCollection 2020 Oct.

The magnetic field in magnetic resonance imaging guided radiotherapy (MRgRT) delivery systems influences charged-particle trajectories and hence the three-dimensional (3D) radiation dose distributions. This study investigated the dose-response as well as dose-rate and fractionation dependencies of silicone-based 3D radiochromic dosimeters for photon irradiation in a magnetic field using a 0.35 T MRgRT system. We found a linear dose response up to 22.6 Gy and no significant dose-rate dependency as a function of depth. A difference in optical response was observed for dosimeters irradiated in a single compared to multiple fractions. The dosimeter showed clinical potential for verification of MRgRT delivery.

磁共振成像引导放射治疗（MRgRT）输送系统中的磁场会影响带电粒子轨迹，进而影响三维（3D）辐射剂量分布。本研究使用0.35 T MRgRT系统，研究了基于硅酮的3D放射变色剂量计在磁场中进行光子照射时的剂量响应以及剂量率和分次照射依赖性。我们发现，在高达22.6 Gy的剂量范围内呈线性剂量响应，且作为深度函数不存在显著的剂量率依赖性。观察到单次照射与多次照射的剂量计在光学响应上存在差异。该剂量计在MRgRT输送验证方面显示出临床应用潜力。