131I治疗分化型甲状腺癌术后患者辐射剂量预测模型的研究

目的 探讨131I治疗分化型甲状腺癌（DTC）术后患者全身辐射剂量代谢的影响因素，为辐射防护提供指导。 方法 回顾性分析2018年4至9月于3家三甲医院住院的72例DTC术后患者男性27例、女性45例，年龄15~75（42.79±14.23）岁]的临床资料，其中同济大学附属第十人民医院23例、上海交通大学医学院附属仁济医院24例、华中科技大学同济医学院附属协和医院25例。根据服用131I后48 h全身辐射剂量是否达到安全标准将患者分为安全组（48 h全身辐射剂量≤23.30 μSv/h）和危险组（48 h全身辐射剂量>23.30 μSv/h），比较各因素对全身辐射剂量代谢的影响。计量资料的组间比较采用成组t检验或Wilcoxon秩和检验；计数资料的组间比较采用卡方检验或Fisher确切概率法。对各变量进行单因素分析，对单因素分析中差异有统计学意义的变量采用多因素Logistic回归分析。以各单因素及多因素联合指标绘制受试者工作特征（ROC）曲线，评估其最佳临界值及诊断效能。 结果 危险组和安全组比较的单因素分析结果显示，甲状腺2 h摄碘率（t=?2.56，P=0.01）、24 h摄碘率（Z=?2.07，P=0.04）、游离三碘甲腺原氨酸（Z=?2.83，P=0.01）、游离甲状腺素（Z=?2.70，P=0.01）、甲状腺球蛋白（Tg）水平（χ2=6.80，P=0.01）、甲状腺超声提示是否存在甲状腺残留组织（Fisher确切概率法，P=0.03）等6个指标显著影响了131I治疗DTC术后患者的全身辐射剂量代谢。多因素Logistic回归分析结果显示，24 h摄碘率OR=1.27（95%CI:1.03~1.57）]和Tg水平OR=2.51（95%CI:1.21~5.20）]对全身辐射剂量代谢有影响（P=0.03、0.01），24 h摄碘率和Tg水平越高的患者其48 h全身辐射剂量达到安全水平的可能性越低。24 h摄碘率+Tg水平（联合指标）诊断的ROC曲线下面积为0.76（95%CI:0.65~0.87）、灵敏度为94.87%、特异度为46.88%、最佳临界值为?0.71。 结论 24 h摄碘率和Tg水平是131I治疗DTC术后患者全身辐射剂量代谢的影响因素，利用这两个因素建立联合指标进行辐射剂量评估可为调整患者住院时长提供参考。

Prediction model of radiation dose in patients with differentiated thyroid cancer after 131I treatment

Objective To explore the factors affecting the metabolic rate of 131I radiation dose in vivo in patients with differentiated thyroid cancer (DTC) after surgery and 131I treatment to provide guidance for radiation protection. Methods A retrospective analysis was conducted on 72 postoperative patients with DTC (27 males and 45 females, aged 15–75 (42.79±14.23) years old) who were hospitalized in the department of nuclear medicine of three grade 3A hospitals from April to September in 2018. Among the above mentioned patients, 23 were from the Tenth People's Hospital Affiliated to Tongji University, 24 were from Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and 25 were from Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology. The patients were divided into safety groups (48 h whole body radiation dose≤23.30 μSv/h) and risk groups (48 h whole body radiation dose>23.30 μSv/h) depending on whether the whole body radiation dose reached the safety standard 48 h after taking 131I, and the effects of various factors on the whole body radiation dose metabolism between the two groups were compared. The measurement data were compared by group t test or Wilcoxon rank sum test; the intergroup comparison of enumeration data was examined by chi-square test or Fisher's exact test. Univariate analysis was performed on each variable, and multivariate Logistic regression analysis was conducted for variables that were statistically significant in univariate analysis. The receiver operating characteristic (ROC) curve was drawn using each univariate indicator and combined indicators to determine the best critical value and diagnostic efficacy for predicting the efficacy of 131I. Results The univariate analysis results of the comparison between the risk group and the safety group showed that the levels of thyroid iodine uptake rate at 2 h (t=?2.56, P=0.01), iodine uptake rate at 24 h (Z=?2.07, P=0.04), free triiodothyronine (Z=?2.83, P=0.01), free thyroxine (Z=?2.70, P=0.01), thyroglobulin (Tg) (χ2=6.80, P=0.01), and the presence of residual thyroid tissue in ultrasound examination (Fisher's exact test, P=0.03) significantly affected the metabolism of whole body radiation dose in patients with DTC after 131I treatment. The results of multivariate Logistic regression analysis showed that the 24 h iodine uptake rate (OR=1.27(95%CI: 1.03–1.57)), Tg level (OR=2.51(95%CI: 1.21–5.20)) influenced whole body radiation dose metabolism (P=0.03, 0.01). The higher the 24 h iodine uptake rate and the higher the Tg level, the lower the probability that the 48 h whole body radiation dose reached a safe level. The area under the ROC curve of the combined diagnostic index of 24 h iodine uptake rate and Tg level was 0.76(95%CI: 0.65–0.87). The sensitivity was 94.87%, the specificity was 46.88%, and the best critical value was ?0.71. Conclusions The 24 h iodine uptake rate and Tg level were the influencing factors of radiation dose metabolism in patients with DTC after 131I treatment. Therefore, these two factors can be used to establish a combined index to evaluate radiation dose, providing a basis for adjusting the length of hospitalization of patients.