Monte Carlo simulation study of the effect of filter on radiotherapy dosimetry in superficial X-ray therapy apparatus
10.3760/cma.j.cn112271-20240327-00109
- VernacularTitle:浅层X射线治疗机过滤器对放疗剂量学影响的蒙特卡罗模拟研究
- Author:
Li TAO
1
;
Hui ZHANG
;
Yikai WU
;
Junyi LIU
;
Miao QI
;
Ning GAO
;
Yankui CHANG
;
Xi PEI
;
Zhi CHEN
;
Xie XU
Author Information
1. 中国科学技术大学核科学技术学院，合肥 230025
- Publication Type:Journal Article
- Keywords:
Superficial X-ray radiotherapy;
Filter;
Monte Carlo simulation;
Dosimetric optimization
- From:
Chinese Journal of Radiological Medicine and Protection
2025;45(3):194-201
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the dosimetry optimization strategy based on filter thickness and shape selection for the bulb superficial X-ray radiotherapy unit.Methods:Monte Carlo code TOPAS was used to model tubular equipment, and the dose distribution from six X-ray energies (50-150 kV) and five conventional aluminum filters (0.5-3.0 mm) with different thickness were simulated in the water model. The percentage depth dose (PDD) curve along the central axis, the center-axis profile dose at different depths, and the lateral dose distribution were analyzed. The dose distribution of three different designs of aluminum filters (conventional cylindrical, conical and oblique cylindrical filters) was compared to evaluate the effect of dosimetric optimization of different filter shapes.Results:Under the same energy, increasing the thickness of the filter can optimize the superficial skin dose, and the optimization effect of depth dose uniformity can be increased by 26% at a depth of 5.5 mm at 70 kV energy. The raised, flat and inclined dose distribution modes can be achieved by using conventional cylindrical, conical and inclined aluminum filters.Conclusions:By selecting the appropriate X-ray energy and filter thickness, an ideal dose distribution matching the tumor depth can be achieved. The application of personalized filters is also of great significance for diverse target areas.
