Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany.
Institute of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Maximiliansplatz 3, 91054, Erlangen, Germany.
Strahlenther Onkol. 2021 Mar;197(3):246-256. doi: 10.1007/s00066-020-01703-y. Epub 2020 Oct 25.
To share our experiences in implementing a dedicated magnetic resonance (MR) scanner for radiotherapy (RT) treatment planning using a novel coil setup for brain imaging in treatment position as well as to present developed core protocols with sequences specifically tuned for brain and prostate RT treatment planning.
Our novel setup consists of two large 18-channel flexible coils and a specifically designed wooden mask holder mounted on a flat tabletop overlay, which allows patients to be measured in treatment position with mask immobilization. The signal-to-noise ratio (SNR) of this setup was compared to the vendor-provided flexible coil RT setup and the standard setup for diagnostic radiology. The occurrence of motion artifacts was quantified. To develop magnetic resonance imaging (MRI) protocols, we formulated site- and disease-specific clinical objectives.
Our novel setup showed mean SNR of 163 ± 28 anteriorly, 104 ± 23 centrally, and 78 ± 14 posteriorly compared to 84 ± 8 and 102 ± 22 anteriorly, 68 ± 6 and 95 ± 20 centrally, and 56 ± 7 and 119 ± 23 posteriorly for the vendor-provided and diagnostic setup, respectively. All differences were significant (p > 0.05). Image quality of our novel setup was judged suitable for contouring by expert-based assessment. Motion artifacts were found in 8/60 patients in the diagnostic setup, whereas none were found for patients in the RT setup. Site-specific core protocols were designed to minimize distortions while optimizing tissue contrast and 3D resolution according to indication-specific objectives.
We present a novel setup for high-quality imaging in treatment position that allows use of several immobilization systems enabling MR-only workflows, which could reduce unnecessary dose and registration inaccuracies.
分享我们在使用新型线圈在治疗位置进行脑成像的基础上，为放射治疗（RT）治疗计划专门安装磁共振（MR）扫描仪的经验，同时介绍为脑和前列腺 RT 治疗计划专门调整的核心序列方案。
我们的新型设备由两个大型 18 通道柔性线圈和一个特定设计的木制面罩固定器组成，安装在一个平板上，使患者在面罩固定下可以在治疗位置进行测量。该设备的信噪比（SNR）与供应商提供的用于 RT 的柔性线圈和用于诊断放射学的标准设备进行了比较。对运动伪影的发生进行了量化。为了开发磁共振成像（MRI）方案，我们制定了基于特定部位和疾病的临床目标。
与供应商提供的和诊断设置相比，我们的新型设备的平均 SNR 分别为 163±28 在前部，104±23 在中央，78±14 在后部，84±8 和 102±22 在前部，68±6 和 95±20 在中央，56±7 和 119±23 在后部。所有差异均有统计学意义（p>0.05）。基于专家评估，新型设备的图像质量被认为适合勾画。在诊断设备中，有 8/60 名患者发现运动伪影，而在 RT 设备中则没有发现运动伪影。根据特定适应症的目标，设计了特定部位的核心方案，以最小化失真，同时优化组织对比度和 3D 分辨率。
我们提出了一种新型的治疗位置高分辨率成像设备，可用于多种固定系统，实现仅使用 MRI 的工作流程，从而减少不必要的剂量和配准不准确。
