Measurement and simulation of secondary neutron energy spectra and doses in proton therapy
10.13491/j.issn.1004-714X.2026.01.005
- VernacularTitle:质子治疗中次级中子能谱与剂量测量及模拟研究
- Author:
Yang YAN
1
;
Changsong HOU
1
;
Zhen ZHANG
2
;
Weiguo ZHU
1
Author Information
1. National Institute for Radiological Protection, China CDC, Key laboratory of Radiological Protection and NuclearEmergency, Chinese Center for Disease Control and Prevention, Beijing 100088, China.
2. National Center forOccupational Safety and Health, Nation Health Comission of the People’s Republic of China; Key Laboratory of Dust Hazard Engineering Protection, Nation Health Comission of the People's Republic of China, Beijing 102308, China.
- Publication Type:OriginalArticles
- Keywords:
Proton therapy;
Neutron energy spectrum;
Neutron dose;
FLUKA
- From:
Chinese Journal of Radiological Health
2026;35(1):23-28
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the radiation dose levels induced by secondary neutrons at different locations inside proton therapy treatment rooms, and analyze the distribution characteristics of neutron energy spectra by combining experimental measurements with simulations, and to provide a theoretical basis and technical support for radiation protection design and management in proton therapy. Methods Multiple representative measurement points were established in the treatment rooms of two hospital-based proton therapy centers. The DIAMON neutron spectrometer was employed to perform in-situ measurements of secondary neutron doses and energy spectra. Three-dimensional simulation models of treatment rooms were constructed using the FLUKA code to simulate the generation and transport of secondary neutrons. Results Measurements showed that the neutron dose was highest near the target region, reaching up to 4293.750 µSv/h. The doses at the maze entrance were the next highest, ranging from 422.091 to 489.268 µSv/h, while the doses in the middle section of the maze ranged from 2.860 to 6.727 µSv/h. The neutron energy spectra exhibited a triple-peak pattern. Conclusion Significant accumulation of secondary neutrons was observed near the target and in the maze regions during proton therapy, with intermediate-energy neutrons being the dominant dose contributor. The consistency between measurements and simulations validated the reliability of the model, which can provide a basis for optimizing treatment room shielding and controlling occupational exposure for staff.
