距离在甲状腺癌患者^(131)I治疗中的屏蔽作用

Shielding effect of distance in ^(131)I-131 therapy for differentiated thyroid cance

目的探讨距离在分化型甲状腺癌患者131I治疗后的屏蔽作用。方法 87例甲状腺癌患者术后行131I治疗,分为低剂量组(<3.7 GBq)39例及高剂量组(≥3.7 GBq)48例,分别测量患者在不同距离、不同服药时间点以及1.11 GBq的131I参考源放射性辐射剂量和天然本底的放射性辐射剂量。结果高剂量组DTC患者在服药后1 m距离的辐射剂量明显高于低剂量组(P<0.05);不同剂量组在其它时间点及距离之间辐射剂量差别无统计学意义(P>0.05)。在服药后第3天,1 m距离的辐射剂量明显低于1.11GBq的131I参考源的辐射剂量(P<0.05),但3 m距离的放射性辐射剂量仍高于天然本底的辐射剂量(P=0.000)。结论分化型甲状腺癌患者在接受131I治疗3 d后辐射剂量迅速降低。服药后第3天辐射剂量明显低于国家规定的1.11 GBq131I的辐射剂量,患者可以予以出院,公众人员在1 m以上的距离接触患者是安全的。

Objective To investigate the shielding effect of distance in radioactive iodine treatment in patients with differentiated thyroid cancer （DTC）. Methods Eighty- seven DTC patients underwent postoperative radioactive iodine treatment at the therapeutic doses ranging from 2.96 GBq to 7.4 GBq. The patients were divided into two groups to receive high-dose therapy （≥3.7 GBq, 48 patients） and low-dose therapy （＆lt;3.7 GBq, 39 patients）. The radiation doses at 0.05 m, 1 m, and 3 m were recorded at different days;the doses at 1 m and 3 m on the third day, the dose of standard radioactivity source of 1.11GBq 131I, and the natural background radioactivity were also recorded. Results The radiation dose at a 1-meter distance was significantly higher in the high-dose group than in the low-dose group （P＆lt;0.05）. The radiation doses in different dose groups at the other distances or at different time points showed no significant differences （P＆gt;0.05）. On the third day after therapy, the radiation dose at 1 m was significantly lower than the reference radioactivity source of 1.11 GBq 131I （P=0.000）, but still higher than the natural background radioactivity at 3 m （P=0.000）. Conclusion In DTC patients who receive radioactive iodine therapy, the radioactive radiation dose decreases rapidly after 3 days. The radioactive radiation dose on the third day is significantly lower than the reference radioactive radiation dose, so that the patients can be discharged with safety for contact at a distance beyond one meter.