The correct estimation of water equivalent ratio (WER) and the associated errors is highly important for the delivery of carbon-ion (C-ion) beams. In the case of MRI-guided C-ion radiotherapy (MRgCT) scenario, as a therapeutic approach for future potential MR-guided particle therapy, C-ion beam will be deflected in the presence of the magnetic field. The curvature of the track causes a retraction of the range. This range variation might be different in various materials, which leads to change the WER values. To evaluate the WER variations versus magnetic field strength, in this research work, WER of some materials, including bladder, brain, prostate, muscle, bone, polymethylmethacrylate (PMMA), polyoxymethylene (POM), polyethyleneterephthalate (PET), titanium (Ti), gold (Au), platinum (Pt); potentially encountered in C-ion radiotherapy dosimetry were assessed. A mono-energetic C-ion beam, incident on a volume containing materials as mentioned above, was simulated using the FLUKA ...

中文翻译：

---

横向磁场对碳离子放射治疗中水当量比的影响

正确估计水当量比（WER）和相关的误差对于传递碳离子（C离子）束非常重要。在MRI引导的C离子放射疗法（MRgCT）情况下，作为未来潜在的MR引导的粒子疗法的治疗方法，C离子束将在磁场作用下发生偏转。轨道的曲率会导致范围缩回。在各种材料中，此范围变化可能会有所不同，从而导致WER值发生变化。为了评估WER对磁场强度的变化，在这项研究工作中，我们对某些材料的WER进行了研究，包括膀胱，大脑，前列腺，肌肉，骨骼，聚甲基丙烯酸甲酯（PMMA），聚甲醛（POM），聚对苯二甲酸乙二醇酯（PET），钛（Ti） ，金（Au），铂（Pt）；评估了在C离子放射治疗剂量法中可能遇到的情况。使用FLUKA模拟了单能C离子束，入射到包含上述材料的体积上。