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 differen