Abstract: Preablation sTg level,sTg/TSH ratio and sTg×TgAb product as predictors of iodine 131I therapeutic effect in patients with differentiated thyroid cancer following total thyroidectomy        PAN Meng-jiao, JIA Meng, LI Zhu-yao, et al. Department of Thyroid Surgery, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
 Corresponding author: LU Xiu-bo, E-mail:doctorluxiubo@126.com 
Abstract    Objective    To analyze the reliability of the stimulated thyroglobulin (sTg), sTg/ thyroid-stimulating hormone (TSH) ratio and the product of sTg times anti-thyroglobulin antibody (TgAb) in predicting the efficacy of radioactive iodine (131I) therapy (RIT) for patients with differentiated thyroid carcinomas (DTCs) after total thyroidectomy (TT). Methods    The clinical characteristics of 302 DTC patients in the First Affiliated Hospital of Zhengzhou University from 2019 to 2020 were analyzed retrospectively. According to the classification of therapeutic response of 131I therapy, patients with excellent response (ER) were included in excellent response group (176 cases), and patients with indeterminate response (IDR), biochemical incomplete response (BIR) or structural incomplete response (SIR) were included in incomplete response group (126 cases). The receiver operating characteristic curve was performed to analyze and compare the reliability of the sTg level, sTg/TSH ratio and sTg×TgAb product in predicting the efficacy of RIT. Univariate and multivariate logistic regression analysis were used to identify independent risk factors for poor 131I treatment. Results    The area under the curve (AUC) of the sTg level, sTg/TSH ratio and sTg×TgAb product for predicting the efficacy of RIT were 0.809, 0.789, 0.870, respectively. And the cutoff values of three predictive factors were 2.735 μg/L, 0.038, 28.364, while the sensitivities were 72.2%, 60.3%, 88.1% and the specificities were 86.4%, 92.0%, 72.2%, respectively. There were significant differences among the ROC curves of the three predictive factors. Univariate and multivariate logistic regression analysis showed that lateral lymph nodes (LN) metastasis, RIT doses, TgAb, sTg＞2.735 μg/L, and sTg×TgAb product＞28.364 were the independent risk factors (P＜0.05) for poor 131I treatment. Conclusion    The sTg level, sTg/TSH ratio, and sTg×TgAb product are valuable for predicting the efficacy of RIT in differentiated thyroid carcinoma. Meanwhile, the predictive ability of the sTg×TgAb product is better than sTg level and sTg/TSH ratio. sTg＞2.735 μg/L and sTg×TgAb product＞28.364 are the independent risk factors of poor 131I treatment. STg×TgAb might be an important marker for the evaluation of the iodine 131I therapeutic effect. 

Key words: differentiated thyroid carcinomas, stimulated thyroglobulin, anti-thyroglobulin antibody, iodine 131I therapy, predictive value

摘要： 目的    分析分化型甲状腺癌（DTC）术后首次131I治疗前血清刺激性甲状腺球蛋白（sTg）、sTg与促甲状腺激素（TSH）的比值以及sTg与抗甲状腺球蛋白抗体（TgAb）的乘积对131I疗效的预测价值。方法    回顾性分析2019—2020年郑州大学第一附属医院302例DTC病人的临床特征资料，根据131I疗效反应的分类将疗效满意的病人纳入疗效满意组（176例），将疗效不确切、生化疗效不佳及结构性疗效不佳的病人纳入疗效不佳组（126例）。采用受试者工作特征（ROC）曲线模型分析并比较sTg、sTg/TSH及sTg×TgAb对131I疗效的预测价值。采用单因素及多因素Logistic回归分析明确131I疗效不佳的独立危险因素。结果    sTg、sTg/TSH和sTg×TgAb预测131I疗效的曲线下面积（AUC）分别为0.809、0.789、0.870，最佳临界值分别为2.735mg/L、0.038、28.364，敏感度分别为72.2%、60.3%、88.1%，特异度分别为86.4%、92.0%、72.2%。三者ROC曲线两两之间差异有统计学意义（P＜0.05）。单因素及多因素Logisic回归分析示侧区淋巴结转移、服碘剂量、TgAb、sTg＞2.735 mg/L和sTg×TgAb＞28.364是131I疗效不佳的独立危险因素。结论    sTg、sTg/TSH和sTg×TgAb均可在一定程度上预测131I的疗效，且sTg×TgAb的预测能力优于sTg和sTg/TSH，其中sTg＞2.735 mg/L及sTg×TgAb＞28.364是131I疗效不佳的独立危险因素。临床可将sTg×TgAb作为预测DTC病人术后131I疗效的参考指标。

关键词: 分化型甲状腺癌, 刺激性甲状腺球蛋白, 抗甲状腺球蛋白抗体, 131I治疗, 预测价值