模拟后装放射源卡源处置时放射工作人员受照剂量研究

Estimation of radiation dose of workers in dealing with the lock of afterloading source

目的估算放疗技师在应急处理后装放射源卡源过程中的受照剂量。方法使用仿真人体盆腔模型替代宫颈癌患者,填充石蜡的假人替代放疗技师,模拟放射源在患者的子宫口位置发生卡源事故的场景,采用热释光剂量仪测量假人的4个敏感器官(晶体、甲状腺、乳腺、睾丸)表面不同时长内的受照剂量,并计算穿戴0.35 mm铅当量的防护用品的防护效果。结果按192 Ir源强370 GBq计,无防护情况下各敏感器官在不同处理时间的受照剂量均小于0.12 mGy。在穿戴防护用品之后,各敏感器官的受照剂量减少1.7%~19.8%。结论放疗技师在没有穿戴防护用品,192 Ir源强为370 GBq,应急处理时间35 s内的入射体表剂量不超过0.12 mGy,只相当于做一次X线摄影检查的受照剂量。

Objective To estimate the radiation dose of workers in dealing with the lock of the afterloading source.Methods Two phantoms were used to simulate the cervical cancer patient and the radiation worker,thermoluminescent dosimeters(TLD)were placed on surfaces of the phantom mimicked the worker in dealing with the lock of source,and the entrance surface doses(ESD)of the four radiosensitive organs(eye lens,thyroid,breast,gonald)were monitored.Results If the source strength was 370 GBq,the ESD of each OAR would be less than 0.12 mGy in whichever handling time and 1.7%~19.8%decrease after dressing the phantom with the radiation protective clothing.Conclusion In the case of source strength 370 GBq and the handling time 35 s,the ESD of therapist is less than 0.12 mGy without wearing the radiation protective clothing,which amount to the ESD of X ray radiographic examination only once.