甲状腺乳头状癌患者术后碘摄入量与131I清除残余甲状腺组织疗效关系分析

Association between iodine intake and treatment outcomes of radioiodine remnant ablation in patients with papillary thyroid cancer

目的探讨甲状腺乳头状癌（PTC）患者术后碘摄人量与131I清除残余甲状腺组织（简称清甲）疗效的关系，并分析影响疗效的相关因素。方法回顾性分析2013年1月至2014年5月临床病理资料完整且无远处转移的95例PTC患者（男28例，女67例；平均年龄39．8岁），在首次131I清甲治疗前患者均行甲状腺全切除术及低碘饮食2-4周。根据患者尿碘水平分为3组：中重度碘缺乏组（0〈尿碘〈50μg/L），30例；轻度碘缺乏组（50μg／L≤尿碘〈100μg/L），26例；碘摄人适宜组（100pg,／L≤尿碘〈300μg／L），39例。131I清甲治疗后3—6个月随访疗效，符合以下条件之一视为首次131I清甲成功，否则为未成功：（1）诊断剂量131I全身显像，甲状腺床未见放射性浓聚影且TgAb阴性情况下Tg〈2pc／L；（2）治疗剂量131I全身显像，甲状腺床未见放射性浓聚影。数据分析采用疋。检验、两样本t检验、Mann．Whitneyu秩和检验和logistic回归模型。结果95例PTC患者术后1次131I清甲治疗成功率为84．2％（80／95），中重度碘缺乏组、轻度碘缺乏组和碘摄入适宜组清甲成功率分别为96．7％（29／30）、84．6％（22／26）和74．4％（29／39），组间疗效差异有统计学意义（χ2=7．374，P〈0．05）。单因素分析显示，碘摄入量、治疗前TSH、治疗前Tg、残余甲状腺质量均与清甲疗效有关（χ2=7．374，t=2．037，z=-2．966,χ2=4．144，均P〈0．05）。Logistic回归分析显示，影响清甲疗效的重要因素为治疗前Tg和碘摄入量（均P〈0．05）。结论PTC患者甲状腺全切除术后，碘摄人量是影响131I清甲成功率的重要因素之一。治疗前可根据患者碘营养水平。合理制定低碘饮食计划，以获得较理想的治疗效果。

Objective To evaluate the association between iodine intake and treatment outcomes of radioiodine remnant ablation in patients with papillary thyroid cancer （PTC）, and to investigate the determinants related to the ablation efficacy. Methods A total of 95 PTC patients （ 28 males, 67 females ; average age 39.8 years） without distant metastases from January 2013 to May 2014 were enrolled in this retrospective study. All patients underwent total thyroidectomy and 2-4 weeks of low iodine diet （LID） before initial 131I therapy. Patients were divided into 3 groups according to urinary iodine excretion （UIE） ： moderate-severe iodine deficiency group （0〈UIE〈50 μg/L, n= 30）, mild iodine deficiency group （50μg/L≤UIE〈100 μg/L, n=26） , adequate iodine group （100 μg/L≤UIE〈300 μg/L, n= 39）. Patients were followed up for 3-6 months after radioiodine ablation, successful ablation was defined as no visible uptake in the thyroid bed on diagnostic 131I whole body scan and rig level 〈2 μg/L （with negative TgAb） , or no visible uptake in thy- roid bed on posttreatment 131I whole body scan. χ2 test, two-sample t test, Mann-Whitney u test and logistic regression analysis were performed. Results In all, 84.2% （ 80/95 ） of patients were successfully ablated. The successful rates in the three iodine intake groups were 96.7% （29/30） , 84.6% （22/26） and 74. 4% （ 29/39）, respectively, with significant difference （χ2 = 7.374, P〈 0.05 ）. Univariate analysis revealed that UIE, pre-treatment TSH, pre-treatment Tg and the amount of remnant thyroid tissue at ablation affected ab- lation efficacy （χ2 = 7.374, t = 2.037, z = -2.966 ,χ2 = 4.144, all P〈 0.05 ）. Logistic regression showed that the level of pre-treatment Tg （ P 〈 0.05 ） and iodine intake （ P 〈 0.05 ） were independent factors of ablation efficacy. Conclusion Iodine intake before 131I remnant ablation is one of the important factors affecting treatment outcomes. Thyroid remnant could be more successfully ablated if reasonable LID protocols be adopted according to the iodine nutritional status before treatment.