南京“5．7”^192Ir源放射事故患者早期物理剂量估算

Physical dose estimation for the patient in early stage of ＂5.7＂ ^192Ir source accident in Nanjing

目的 对南京＂5.7＂192Ir源放射事故中,1例局部受大剂量外照射的患者的受照剂量进行快速估算。方法 在获知放射源参数、照射方式和照射时间的基础上,基于东亚人体素体模和受照者主要生理特征,利用蒙特卡罗模拟软件包MCNP建立模型并估算。结果 估算了受照患者16个器官的吸收剂量,数值范围为0.03-9.16 Gy。腿部皮肤的等剂量曲线清晰显示了左、右腿部皮肤的剂量差异。受照者睾丸、前列腺受照剂量较大,吸收剂量数值约9.16 Gy。大腿皮肤受到局部大剂量照射,双腿皮肤剂量估算结果与红外热成像仪探测结果基本一致。结论 结合恰当受照模型的蒙特卡罗技术和模拟软件包可有效用于放射事故患者的早期物理剂量估算。

Objective To make a rapid dose estimation for a patient exposed locally to high dose radiation exposure in early stage of ＂5.7＂ 192Ir source accident in Nanjing.Methods Based on source parameters, exposure pattern, and time duration, the doses were estimated using MCNP simulations with the aid of the proper East Asia adult male voxel phantom and main physiological parameters of the exposed patient. Result Absorbed doses to 16 organs or tissues were estimated to be in the range 0.03 to 9.16 Gy. Also, the iso-dose curves for the skin of legs showed clearly the dose difference between right and left legs. Absorbed doses to patient＇s testicles and prostrate, about 9.16 Gy, were higher than those to other organs or tissues. The skin of both legs was exposed locally to high dose radiation exposure, for which the estimated doses were in agreement with the results obtained from infrared thermal imaging. Conclusions Monte Carlo simulation technique and common software can be used for dose estimation in early stage of radiation accidents effectively with integrating proper models.