Analysis of radiation dose at the entrance of the medical linear accelerator treatment room
10.13491/j.issn.1004-714X.2022.06.004
- VernacularTitle:医用电子直线加速器治疗机房入口辐射剂量分析
- Author:
Zhiqiang XU
1
;
Jiwu GENG
1
;
Yuxin JIA
1
;
Zaoqin ZHANG
1
;
Meixia WANG
1
Author Information
1. Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510300 China.
- Publication Type:Journal Article
- Keywords:
Accelerator;
Entrance dose rate of the treatment room;
FLUKA program
- From:
Chinese Journal of Radiological Health
2022;31(6):663-668
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the radiation dose at the entrance of the accelerator treatment room, and to guide the radiation protection detection at the entrance of the treatment room. Methods The FLUKA program was used to build the model of accelerator head and treatment room. Under the simulation conditions of 10 MV and 600 cGy/min for the accelerator, the radiation dose rate inside the entrance of the treatment room was measured at different gantry angles, irradiation conditions, and labyrinths. Results The entrance dose rate with a water tank was significantly higher than that without a water tank under different inner labyrinth wall thicknesses and gantry angles. The entrance dose rate reached the maximum at the inner labyrinth wall thickness of 1800 mm and the gantry angle of 90°. When the inner labyrinth wall thickness was 1000 mm and the gantry angles were 0° and 180°, the entrance dose rate was significantly higher than that at other conditions. The dose rate at the entrance of the treatment room reached (82.26 ± 48.95) μSv/h to (314.09 ± 96.34) μSv/h under the following conditions: the inner labyrinth wall thickness of 1800 mm, the gantry angle of 90°, with a water tank, and the width of the inner labyrinth entrance of 1400-2200 mm. Conclusion The dose at the entrance of the accelerator treatment room mainly comes from the scattering and leakage radiation of the useful wire harness on the patient’s body surface, and the entrance dose rate increases with the increase in the width of the inner labyrinth entrance. In the entrance protection test, the gantry angle should be determined considering the inner labyrinth wall thickness, and the test should be performed at four angles in the uncertain case to ensure the comprehensiveness and accuracy of test results.
