机器人用于分化型甲状腺癌术后131I治疗住院患者体内残留放射性活度测定的研究

Measurement of residual radioactivity in postoperative inpatients with differentiated thyroid carcinoma after 131I treatment using robot

目的用核医学科病房服务机器人评估分化型甲状腺癌(DTC)术后患者131I治疗后体内的放射性活度,并确定患者解除隔离时间。方法纳入2017年9月至2018年6月间行131I治疗的297例DTC术后患者,男94例、女203例,年龄19~80岁。根据治疗目的和131I治疗剂量将其分为8组:4个清除残余甲状腺组织(简称清甲)组(清甲1~4组),分别采用3 700 MBq(34例)、4 440 MBq(122例)、5 550 MBq(81例)和7 400 MBq(27例)131I清甲;4个清除DTC无法切除的转移灶(简称清灶)组(清灶1~4组),分别采用3 700 MBq(1例)、4 440 MBq(2例)、5 550 MBq(14例)和7 400 MBq(16例)131I清灶。采用核医学科病房服务机器人分别于患者服用131I后4、24、48和72 h测定距其颈部2 cm及距其体部1 m处的剂量当量率。采用Kruskal-Wallis秩和检验与Mann-Whitney U检验比较清甲、清灶(清灶1组和2组例数少,未行比较研究)不同剂量组间剂量当量率。结果服用131I后4个时间点(4、24、48和72 h)清甲1~4组间的颈部剂量当量率差异均有统计学意义(H值:20.889~46.410,均P<0.05),体部剂量当量率差异也有统计学意义(H值:27.181~35.497,均P<0.05);服用131I后24、48和72 h时清灶3组与4组间颈部剂量当量率差异有统计学意义(z值:2.328~3.076,均P<0.05),而体部剂量当量率差异无统计学意义(z值:0.333~1.621,均P>0.05)。患者体内放射性活度滞留量在24 h迅速减少,随后逐渐变缓,72 h时剂量当量率低。服用131I后72 h有96.6%(255/264)的清甲患者和100%(33/33)的清灶患者周围剂量当量率低于23.3 μSv/h,可解除住院隔离状态。结论核医学科病房服务机器人可动态测量DTC术后服131I患者体内残留放射性活度,为患者提供个体化的隔离方案。

Objective To evaluate the residual radioactivity after 131I treatment in postoperative inpatients with differentiated thyroid carcinoma (DTC) using service robot in nuclear medicine ward, and assess the time for patients to be released from isolation. Methods From September 2017 to June 2018, 297 patients (94 males, 203 females, age: 19-80 years) with DTC who underwent 131I treatment after surgery were included. According to the purpose of treatment and the prescription dosage of 131I, patients were divided into 8 groups: 4 groups accepted 131I remnant ablation therapy (RAT) with different dosages, which were 3 700 MBq (RAT1, n=34), 4 440 MBq (RAT2, n=122), 5 550 MBq (RAT3, n=81) and 7 400 MBq (RAT4, n=27), respectively;4 groups had 131I treatment for recurrent/metastatic lesions (RMLT), and the dosages were 3 700 MBq (n=1), 4 440 MBq (n=2), 5 550 MBq (n=14) and 7 400 MBq (n=16). At 4, 24, 48 and 72 h after 131I administration, the dose equivalent rates at 2 cm away from the patient′s neck and at 1 m away from the body were measured by the robot designed for nuclear medicine ward. Kruskal-Wallis rank sum test and Mann-Whitney U test were used to analyze the data. Results Neck dose equivalent rates for patients with RAT at different time points (4, 24, 48 and 72 h) after 131I administration were significantly different among 4 groups (H values: 20.889-46.410, all P<0.05), as well as the body dose equivalent rates (H values: 27.181-35.497, all P<0.05). The neck dose equivalent rates at 24, 48 and 72 h after 131I administration were statistically different between group 3 and 4 for patients with RMLT (z values: 2.328-3.076, all P<0.05;data in group 1 and 2 were too limited to be compared), while there was no statistical difference for the body dose equivalent rates (z values: 0.333-1.621, all P>0.05). The radioactivity retention in patients decreased rapidly within 24 h, then slowed down gradually and became extremely low at 72 h. At 72 h after 131I administration, 96.6%(255/264) patients with RAT and 100%(33/33) patients with RMLT were lower than 23.3 μSv/h, which meant the patients could be discharged from hospitalization. Conclusions Nuclear medicine ward service robots may dynamically measure residual radioactivity in DTC patients who take 131I treatment, providing individualized isolation solutions.