Quality assurance is particularly important for modulated radiotherapies which improve dose conformity and involve complex processes of dose delivery. This work proposes a dose measurement method based on a rotational optical fiber array and the Cherenkov effect as an alternative pretreatment quality assurance method. Monte Carlo simulation toolkit Geant4 is used to study the accuracy and influencing factors of this method. Four different shapes of radiation field are designed to explore the influence of different reconstruction algorithms, fiber spacing, rotation angles, and radiation types on the accuracy of dose field measurement. The results show that the difference between the reconstructed dose field and the reference dose field is within 8% under the irradiation of uniform radiation field. To obtain high-precision reconstructed images, the fiber spacing should be within 2 mm, and at least 60 angles of projection data should be acquired when the fiber array is rotated 180°. In conclusion, the proposed new method using a rotating fiber array can reconstruct the radiation field distribution rapidly, and provides accurate information on the shape and intensity distribution of the radiation field. Further studies are needed to improve the accuracy and feasibility in real clinical practice.

质量保证对于提高剂量一致性并涉及复杂剂量输送过程的调制放射疗法尤为重要。这项工作提出了一种基于旋转光纤阵列和切伦科夫效应的剂量测量方法，作为一种替代的预处理质量保证方法。蒙特卡罗仿真工具包Geant4用于研究该方法的准确性和影响因素。设计了四种不同形状的辐射场，以探索不同重建算法，光纤间距，旋转角度和辐射类型对剂量场测量精度的影响。结果表明，在均匀辐射场的照射下，重构剂量场与参考剂量场之间的差异在8％以内。为了获得高精度的重建图像，光纤间距应在2 mm之内，并且当光纤阵列旋转180°时，至少应获得60个角度的投影数据。总之，所提出的使用旋转纤维阵列的新方法可以快速重建辐射场分布，并提供有关辐射场的形状和强度分布的准确信息。需要进行进一步的研究以提高实际临床实践中的准确性和可行性。