腹盆腔肿瘤^(125)I粒子植入术后个体化防护临床研究

Clinical study on individual protection after ^(125)I seed implantation for abdominal and pelvic tumors

目的研究腹盆腔肿瘤患者^(125)I粒子植入术后周围环境的受照剂量率及有效剂量,为不同人群的安全防护提供参考。方法采用袖珍辐射仪,监测42例腹盆腔肿瘤患者^(125)I粒子植入术后24 h内,距离植入部位各方向不同距离的受照剂量率,比较不同方向不同距离的剂量率差异。对植入粒子的总活度与测量的剂量率及植入深度与标准活度下剂量率进行曲线拟合并得出关系方程。根据公式计算不同人群、不同距离受照射的剂量率与警戒时间的关系。结果距垂直粒子植入部位30、50、100 cm的受照剂量率分别为(6.92±2.87)、(4.10±1.62)和(1.30±0.48)μSv/h,差异有统计学意义(χ^(2)=73.71,P<0.05)。患者左、右侧面30、50、100 cm受照剂量率分别为(0.378±0.156)和(0.384±0.153)μSv/h、(0.170±0.089)和(0.176±0.086)μSv/h、(0.039±0.014)和(0.043±0.017)μSv/h,差异均有统计学意义(χ^(2)=76.19、76.33,P<0.05)。垂直粒子植入部位的受照剂量率与植入粒子总活度及标准活度下剂量率与植入深度呈线性关系。患者对同住成年人无警戒时间,同床成年人、接触同事、同住未成年人及孕妇的警戒时间与剂量率的关系公式分别为:t(d)=-106.616+83.779lnD(t)、t(d)=26.556+85.933lnD(t)、t(d)=3.088+85.017lnD(t)。结论^(125)I粒子植入术后患者,监测其周边环境的辐射剂量在辐射安全范围内;且随着植入粒子总活度的减小及植入深度的增大剂量率减小;同时根据术后测得的剂量率或植入粒子的总活度、植入粒子的深度计算不同人群的警戒时间,进行个体化防护。

Objective To study the radiation dose rate and effective dose in ambient environment due to ^(125)I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors,so as to provide reference for occupational protection of different groups.Methods Within 24 hours after operation,the radiation dose rate to 42 patients with abdominal and pelvic tumor with ^(125)I seed implantation was monitored by using pocket dosimeter.The relationships between the total activity in the implanted particles and the measured dose rate,as well as between the implanted depth and the dose rate under the standard activity,were obtained by curve fitting.According to the formula,the relationship between the dose rate and the warning time was calculated.Results The dose rates at 30 cm,50 cm and 100 cm of vertical particle implantation site were(6.92±2.87),(4.10±1.62)and(1.30±0.48)μSv/h,respectively(χ^(2)=73.71,P<0.05).The dose rates on the left and right sides were(0.378±0.156)and(0.384±0.153)μSv/h at 30 cm,(0.170±0.089)and(0.17±0.086)μSv/h at 50 cm,(0.039±0.014)and(0.043±0.017)μSv/h at 100 cm,respectively(χ^(2)=76.19,76.33,P<0.05).There was a linear relationship between the dose rate at the vertical particle implantation site and the total activity in the implanted particles,and between the dose rate and the implantation depth under the standard activity.The relationship between the warning time and the dose rate to adults in the same bed,co-workers,minors in the same bed and pregnant women were as follows:t(d)=-106.616+83.779lnD(t),t(d)=26.556+85.933lnD(t),t(d)=3.088+85.017lnD(t).Conclusions After^(125)I seed implantation,the radiation dose in the ambient environment is low,ensuring the radiation safety;and the measured dose rate decreases with the decrease in the total activity in the implanted particle and the increase in the implantation depth;at the same time,the warning time for different groups is calculated according to the measured dose rate or the total activity in the implanted particle and the depth of the implanted particle,so as to carry out individualized protection.