Schneider David F, Sonderman Philip E, Jones Michaela F, Ojomo Kristin A, Chen Herbert, Jaume Juan C, Elson Diane F, Perlman Scott B, Sippel Rebecca S
Section of Endocrine Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA,
Ann Surg Oncol. 2014 Dec;21(13):4174-80. doi: 10.1245/s10434-014-3858-4. Epub 2014 Jul 8.
Persistent or recurrent hyperthyroidism after treatment with radioactive iodine (RAI) is common and many patients require either additional doses or surgery before they are cured. The purpose of this study was to identify patterns and predictors of failure of RAI in patients with hyperthyroidism.
We conducted a retrospective review of patients treated with RAI from 2007 to 2010. Failure of RAI was defined as receipt of additional dose(s) and/or total thyroidectomy. Using a Cox proportional hazards model, we conducted univariate analysis to identify factors associated with failure of RAI. A final multivariate model was then constructed with significant (p < 0.05) variables from the univariate analysis.
Of the 325 patients analyzed, 74 patients (22.8 %) failed initial RAI treatment, 53 (71.6 %) received additional RAI, 13 (17.6 %) received additional RAI followed by surgery, and the remaining 8 (10.8 %) were cured after thyroidectomy. The percentage of patients who failed decreased in a stepwise fashion as RAI dose increased. Similarly, the incidence of failure increased as the presenting T3 level increased. Sensitivity analysis revealed that RAI doses <12.5 mCi were associated with failure while initial T3 and free T4 levels of at least 4.5 pg/mL and 2.3 ng/dL, respectively, were associated with failure. In the final multivariate analysis, higher T4 (hazard ratio [HR] 1.13; 95 % confidence interval [CI] 1.02-1.26; p = 0.02) and methimazole treatment (HR 2.55; 95 % CI 1.22-5.33; p = 0.01) were associated with failure.
Laboratory values at presentation can predict which patients with hyperthyroidism are at risk for failing RAI treatment. Higher doses of RAI or surgical referral may prevent the need for repeat RAI in selected patients.
放射性碘（RAI）治疗后持续性或复发性甲状腺功能亢进很常见，许多患者在治愈前需要额外剂量的治疗或手术。本研究的目的是确定甲状腺功能亢进患者RAI治疗失败的模式和预测因素。
我们对2007年至2010年接受RAI治疗的患者进行了回顾性研究。RAI治疗失败定义为接受额外剂量和/或全甲状腺切除术。使用Cox比例风险模型，我们进行单因素分析以确定与RAI治疗失败相关的因素。然后用单因素分析中有统计学意义（p<0.05）的变量构建最终的多因素模型。
在分析的325例患者中，74例（22.8%）初始RAI治疗失败，53例（71.6%）接受了额外的RAI治疗，13例（17.6%）接受额外RAI治疗后又接受了手术，其余8例（10.8%）在甲状腺切除术后治愈。随着RAI剂量增加，治疗失败患者的百分比呈逐步下降趋势。同样，随着初始T3水平升高，失败的发生率增加。敏感性分析显示，RAI剂量<12.5mCi与治疗失败相关，而初始T3和游离T4水平分别至少为4.5pg/mL和2.3ng/dL与治疗失败相关。在最终的多因素分析中，较高的T4水平（风险比[HR]1.13；95%置信区间[CI]1.02 - 1.26；p = 0.02）和甲巯咪唑治疗（HR 2.55；95%CI 1.22 - 5.33；p = 0.01）与治疗失败相关。
就诊时的实验室检查值可预测哪些甲状腺功能亢进患者存在RAI治疗失败的风险。较高剂量的RAI或手术转诊可能避免部分患者重复进行RAI治疗。
