^(131)I治疗的Graves病住院患者对医务人员造成的辐射剂量监测

Medical staff exposure dosimetry in Graves disease inpatients ^(131)I therapy

目的:监测131I治疗毒性弥漫性甲状腺肿(Graves病)住院患者对医务人员造成的辐射剂量水平。方法:观察住院接受131I治疗的Graves病患者140例,在服用131I后每日用辐射率仪测定距患者0.5m、1m处空气的辐射率直至患者出院。7名病房护士作为被观察对象,代表从事放射性工作的医务人员受到的照射水平,收集其热释光剂量元件的测定结果。结果:观察期间患者接受131I治疗的总活度为870mCi,每名患者平均服用的131I活度为(6.21±2.67)mCi。测算护士在不同受照距离下的接触时间,为1m距离7min、0.5m距离3min。所有患者在不同距离测定得到的剂量率与工作人员在该距离的接触时间相乘得到该次接触所受到的辐射剂量,将所有的值累加,经换算得到总辐射剂量为1.62mSv。热释光测定结果为2.58mSv,平均(0.37±0.26)mSv。结论:从事131I治疗的医务人员受到照射的最高剂量当量在国家规定的最高限值20mSv之下,即使受照射水平最高的个体也属安全水平。

Objective To observe the radiation exposure level of radioactive iodine therapy for Graves disease patients. Methods After the radio-iodine administration exposure of all 140 inpatients were measured at every hospital day at the distance of 0.5 m and 1 m respectively. Dose equivalent of 7 nurses was observed by thermoluminescent dosimeters (TLD) as the object of the study for all medical staff. Results The total activity of radio-iodine during the study period was 870 mCi (6.21±2.67)mCi per patient. The average exposure time at different distance is 7 min at 1 m and 3 min at 0.5 m (including the exposure time for this study). The TLD results of the 7 staff is 2.58 mSv in total and the average is (0.37±0.26) mSv. Dosimetry was calculated with the sum of all patients exposure value multiply by the time in different distance. Conclusion The calculation and measurement of dose equivalence is lower than the upper limit of the government 20 mSv. It suggests that exposure level of the staff is safe even for the highest one.