Development of a 3D dose distribution validation water tank for rotating Gantry treatment terminals

In order to ensure the accuracy of the dose received by the patient in radiotherapy, it is usually necessary to verify the plan before treatment, and the water tank is widely used to achieve this purpose. However, the existing dose validation tanks can only be used for horizontal, vertical and 45° beamline. And those water tanks are inefficient, which cannot meet the multi-angle dose validation requirements of the advanced rotary Gantry beamline treatment rooms. This study aims to meet the beam detection requirements of multi-directional irradiation of Gantry beamline, a 3D water tank for multi-angle beam dose verification was developed. [Methods] The water tank box was made of Polymethyl Methacrylate (PMMA) material, which could be rotated around the isocenter under the drive of the motor. The structure of the water tank was simulated by using Solidworks Simulation software package, and the motion accuracy of the 3D motion mechanism was evaluated. The lateral profile dose distribution of the beam at different depths in the water was measured by a multi-strip ionization chamber, and a 3D dose distribution of the pencil beam can be obtained. The measured results were compared with those of a PTW water tank. [Results] According to the test results, the maximum position error of the probe is 0.132mm when the probe is moving in the depth direction, the maximum position error of the probe is 0.24mm in the Y and Z directions for the probe position adjustment, and the dose measurement deviation is 0.5%±1.18%. [Conclusions] By measuring the lateral profile dose distribution of the beam at different depths in the water, the water tank can quickly and accurately provide the 3D dose distribution of a pencil beam. This device can provide basic data for treatment planning systems and improve the efficiency of regular quality assurance practice. At the same time, with high precision of the 3D motion mechanism, the structure of the water tank is reliable, and the whole measuring device can be rotated around the isocenter of the treatment head. Therefore, this device can meet the beam detection requirements of multi-directional irradiation in the Gantry treatment rooms.

为保障放射治疗中患者受照剂量的准确性，临床通常需在治疗前对治疗计划进行验证，而水箱是实现该验证的常用设备。然而现有剂量验证水箱仅可适配水平、垂直及45°射束线，且检测效率低下，无法满足先进旋转机架射束线治疗室的多角度剂量验证需求。为满足机架射束线多方向照射的束流检测需求，本研究研发了一款可实现多角度束流剂量验证的三维水箱。【方法】该水箱箱体采用聚甲基丙烯酸甲酯（Polymethyl Methacrylate，PMMA）材料制成，可在电机驱动下围绕等中心旋转。通过Solidworks Simulation仿真软件对水箱结构进行仿真分析，并评估三维运动机构的运动精度。采用多条形电离室测量射束在水中不同深度处的横向剖面剂量分布，可获取笔形束的三维剂量分布，并将测量结果与PTW水箱的测量结果进行对比。【结果】测试结果显示，探头沿深度方向运动时的最大位置误差为0.132mm；在Y、Z方向进行探头位置调整时，最大位置误差为0.24mm；剂量测量偏差为0.5%±1.18%。【结论】通过测量射束在水中不同深度处的横向剖面剂量分布，本水箱可快速、准确地获取笔形束的三维剂量分布，可为治疗计划系统提供基础数据，提升常规质量保证工作的效率。同时，由于三维运动机构精度较高、水箱结构可靠，整套测量装置可围绕治疗头等中心旋转，因此该设备可满足机架治疗室多方向照射的束流检测需求。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于开发一种用于旋转机架治疗终端的3D剂量分布验证水箱，旨在解决现有水箱仅适用于特定角度且效率低的问题。通过使用PMMA材料、模拟结构和运动机制，设备实现了高精度（探头位置误差最大0.24mm，剂量测量偏差0.5%±1.18%），能快速提供铅笔束的3D剂量分布，支持治疗计划系统并提升放疗质量保证效率。