ABSTRACT
Objective To calculate the doses and their dose conversion coefficients for the personnel whose organs were under accidental exposure to three types of X-ray machines and two γ radiation sources, and to provide a simple method for rapid estimation of accidental doses. Methods The radiation source models of X-ray machines and two γ sources were established with the FLUKA simulation software and a Chinese reference voxel phantom was imported. The organ absorbed dose, dose conversion coefficient between organ absorbed dose and air Kerma, and conversion coefficient between organ absorbed dose and radiation source were calculated for a simulated scenario where the personnel were under antero-posterior exposure to radiation sources 1 meter away. Results For the lungs, heart, muscles, soft tissue, liver, skin, and brain, the conversion coefficient between organ absorbed dose and air Kerma was 0.30-1.19 (Gy/Gy). For X-ray machines, the conversion coefficient between organ absorbed dose and output for the six organs ranged from 6.12 × 10−3 to 2.90 × 10−2 Gy·m2/(mA·min). For γ radiation sources, the conversion coefficient between organ absorbed dose and activity for the six organs ranged from 1.12 × 10−8 to 7.01 × 10−8 Gy·m2/(GBq·s). Conclusion The conversion coefficient between organ absorbed dose and air Kerma and the conversion coefficient between organ absorbed dose and output or activity of a flaw detector can provide important dosimetric parameters for rapid assessment of similar radiation accidents.
ABSTRACT
In 2003, the responsibility of radiation source safety supervision was redivided and transferred from the health department to the environmental protection department. After the promulgation and implementation of the Rule on the Administration of Radiodiagnosis and Radiotherapy in 2006, due to the incorporation of a large number of medical practice supervision rules, the radiation health supervision of medical institutions has evolved into the radiodiagnosis and radiotherapy supervision. In the past 16 years, radiation, occupational health supervision, and medical practice supervision have not been well integrated, and there are many legal problems in radiodiagnosis and radiotherapy supervision. The regulation rules of environmental protection, metrology, and other relevant departments on radiation sources and radiation devices have been constantly changing, resulting in overly complex regulatory requirements on radiodiagnosis and radiotherapy, which increases the burden of medical institutions. This paper reviews the historical evolution and legal system changes of radiodiagnosis and radiotherapy supervision, analyzes the problems and challenges faced by the relevant regulatory departments, and proposes ways to improve the supervision system.
ABSTRACT
Compared with conventional high energy X-ray radiotherapy, proton/carbon ion has obvious advantages because of its Bragg peak dose distribution. However, proton heavy ion facility has complex structure, high energy and various radiation types due to various nuclear reaction processes, the radiation protection safety brought by the operation of facilities has gradually attracted attention. Taking the proton/carbon ion radiotherapy facility of Shanghai Proton and Heavy Ion Center as an example, the author mainly analyzed the operation principle of proton/carbon ion treatment facility, the basis of radiation protection, analysis of key radiation source points, etc., so as to provide theoretical support and experience for radiation protection.