头颈部125I放射性粒子植入术中及术后患者周围辐射安全评价

目的 对头颈部¹²⁵I粒子植入术中及术后患者周围辐射剂量进行监测和安全评价。方法 40名接受头颈部¹²⁵I粒子植入术的患者按照粒子植入部位分为面颈部组和口腔内组,手术时监测距其皮肤表面30 cm处不同方向的辐射剂量率,术后监测距其皮肤表面30、50和100 cm处不同方向上的辐射剂量率,对口腔内组分别记录患者张口以及闭口状态下的辐射剂量率,参考国家辐射安全标准进行分析研究。结果 手术中位于患者靶区侧的辐射剂量［(2.60±0.37 μSv)］明显大于处于患者颅顶侧［(0.28±0.05)μSv］或靶区对侧［(0.15±0.03)μSv)］(t=25.62、29.51, P＜0.05);术后口腔内组患者张口状态下距其正前方30和50 cm处的辐射剂量率［(21.71±0.92)和(9.50±0.38) μSv/h)大于闭口状态［(9.29±1.14)和(4.61±1 μSv/h)］,差异有统计学意义 (t=35.87、13.70, P＜0.05);而100 cm处分别为(1.54±0.05)和(1.34±0.45)μSv,差异无统计学意义(t=1.94, P >0.05)。面颈部组在距患者靶区侧30、50和100 cm处的辐射剂量率分别为(66.28±3.31)、(35.06±3.05)和(1.72±0.17) μSv/h,大于口腔内组［(52.46±3.54)、(20.78±2.01)和(1.55±0.13)μSv/h］(t=12.74、15.51、3.69, P< 0.05),两组靶区侧100与30 cm相比辐射剂量率减少(t=86.39、63.55、155.44,P＜0.05)。100 cm处面颈部组靶区侧的辐射剂量率为(1.72±0.17)μSv/h,口腔内组正前方张口状态为(1.55±0.13)μSv/h,闭口状态为(1.18±0.42)μSv/h,均符合国家辐射安全标准。结论 头颈部¹²⁵I粒子植入术后患者对医护人员及公众辐射影响很小,注意距离和接触时间以及接触方向可以实现辐射安全。

Safety evaluation in vicinity during and after 125I seeds implantation in head and neck region

Objective To measure the radiation dose during and after~(125)I seeds implantation in head and neck region.and to evaluate the radiation safety in the vicinity.Methods Forty patients who had~(125)I seeds implanted in head and neck region were divided into two groups as facial and neck group as well as intra-oral group.The radiation doses were measured at the distance of 30 cm in three different directions during operation and at the distances of 30,50,and 100 cm after operation when the patients opened and closed their mouth, respectively. Results The radiation dose rate on the treatment side [(2.60±0.37)μSv] was higher than that on the other two sides[(0.28±0.05) and (0.15±0.03)μSv]during the operation,with the statistical difference (t=25.62,29.51,P<0.05).In the intra-oral group,the radiation dose rates at the distances of 30 and 50 cm were higher when the patients opened their mouths[(21.71±0.92) and (9.50±0.38)μSv/h] than those when they closed their mouths [(9.29±1.14) and (4.61±1.61)μSv/h],with the statistical difference (t=35.87,13.70,P<0.05),but without statistical difference at the distance of 100 cm distance [(1.54±0.05) and (1.34±0.45) μSv] (t=1.94.P>0.05).On the treated side at all the distances of 30,50,and 100 cm,the radiation dose rates were higher in the facial and neck group [(66.28±3.31),(35.06±3.05) and (1.72±0.17) μSv/h] than those in the intra-oral group [(52.46±3.54),(20.78±2.01) and (1.55±0.13) μSv/h],with the statistical difference (t=12.74,15.51,3.69.P<0.05).At the distance of 100 cm,the radiation dose rates were(1.72±0.17) μSv/h in facial and neck group,(1.55±0.13) μSv/h when they opened their mouth and (1.1 8±0.42) μSv/h when they closed their mouth in the intra-oral group,which was safe for the public.Conclusions Radiation exposure to the medical workers and the public from the patients is very low.It is easy to achieve the radiation safety by reducing the exposure time,increasing the distance and changing the exposure direction.