不同放射性活度^131Ⅰ清除分化型甲状腺癌患者残留甲状腺的荟萃分析

Different activities of 131I for remnant thyroid ablation in patients with differentiated thyroid cancer： a meta-analysis

目的 使用荟萃分析方法汇总所有的随机对照研究,比较不同放射性活度^131Ⅰ清除术后残留甲状腺（清甲）的成功率,明确最佳的清甲剂量.方法 以‘thyroid’＋‘cancer or carcinoma’＋‘ablat$’（包括了ablation、ablative和ablate）为关键词检索2014年3月前Cochrane Library、MEDLINE、EMBASE和SCOPUS等数据库评估不同放射性活度^131 I清甲成功率的随机对照研究文献,并用Google学术查找相关文献.用RevMan 5.2进行统计学分析,依据Cochrane质量评价标准进行文献质量评估.纳入标准如下：（1）已发表的比较不同剂量^131Ⅰ对分化型甲状腺癌（DTC）清甲成功率的研究.（2）患者均行甲状腺切除术.（3）均为术后首次^131Ⅰ治疗.（4）服^131Ⅰ后3～12个月行清甲成功率评估.（5）服^131Ⅰ剂量为888 ～4 440 MBq（24～120 mCi）.本研究定义低剂量为888～1 443 MBq（24～39 mCi）、中剂量为1 480～2 923 MBq（40 ～79 mCi）、高剂量为2 960～4 440 MBq（80～120 mCi）.当研究间存在异质性时（I^2＞50％）、采用随机效应模型进行荟萃分析,否则采用固定效应模型进行荟萃分析.结果 共纳入17个随机对照研究,包括3 737例患者（低剂量1 514例、中剂量811例、高剂量1 412例）.5项研究比较了低剂量与中剂量的成功率,研究间有异质性（I^2 =67％,P=0.02）、采用随机效应模型,荟萃分析结果显示两组的清甲成功率差异无统计学意义[风险比（RR） =0.89（0.80～1.00）,P=0.06].7项研究比较了中剂量与高剂量的成功率,研究间无异质性（I^2=34％,P=0.17）,采用固定效应模型,荟萃分析结果显示两组剂量的清甲成功率差异无统计学意义[RR =0.94（0.89～1.00）,P=0.05].11项研究比较了低剂量与高剂量的成功率,研究间有异质性（I^2=70％,P=0.0002）,采用随机效应模型,荟萃分析结果显示高剂量的清甲成功率显著高于低剂量[RR=0.89（0.81 ～0.97）,P=0.008].结论 对于术后DTC患者,低剂量与中剂量^131Ⅰ以及中剂量与高剂量^131Ⅰ的清甲成功率无明显差异,但高剂量^131Ⅰ的清甲成功率显著高于低剂量.

Objective To compare the successful rate of different activities of ^131Ⅰ for postoperative remnant ablation in randomized controlled trials （RCTs）,and determine the optimal dose with a meta-analysis.Methods Sources were retrieved from the Cochrane Library,MEDLINE,EMBASE,SCOPUS and Google Scholar until March 2014.The search strategy included the terms：＇thyroid＇ ＋ ＇cancer or carcinoma＇ ＋ ＇ablat $ ＇ （to cover ablation,ablative and ablate）.All RCTs that assessed the efficacy of different doses of ^131Ⅰ for ablation were selected.Statistics were performed by Review Manager 5.2 software.The risk of bias and quality in each eligible study was assessed by Cochrane＇s risk of bias tool.Studies were included for analysis if they met the following criteria：（1） RCTs were published as articles that compared the efficacy of different dose ^131Ⅰ in ablation of differentiated thyroid cancer （DTC）.（2） patients had undergone thyroidectomy.（3） patients were treated with ^131Ⅰ for the first time after surgery.（4） assessed the successful remnant ablation at 3 to 12 months after ^131Ⅰ administration.（5） ^131Ⅰ activity was less than 4 440 MBq （120 mCi） and more than 888 MBq （24 mCi）.We defined low dose as from 888 to 1 443 MBq（24-39 mCi）,moderate dose as from 1 480 to 2 923 MBq （40-79 mCi）,and high dose as from 2 960 to 4 440 MBq （80-120 mCi）.Statistical heterogeneity between studies was assessed by means of I^2 value.A fixed-effect model was used for calculations unless significant heterogeneity existed （I^2 〉 50%）,in which case a random-effect model was used.Results Seventeen RCTs were considered eligible,involving 3 737 patients （1 514 low dose,811 moderate dose and 1 412 high dose）.Five trials compared low versus moderate dose activities.Heterogeneity was found （I^2 =67%,P =0.02）,and the random effect model was used.This analysis showed no significant difference in successful rate of thyroid remnant ablation[risk ratio （RR） =0.89 （0.80 to 1.00）,P =0.06].Seven trials compared moderate versus high dose activities.No heterogeneity was found （I^2 =34%,P =0.17）,and the fixed-effect model was used.This analysis also showed no significant difference [RR =0.94 （0.89 to 1.00）,P =0.05].Eleven trials compared low versus high dose activities.Heterogeneity was found （I^2 =70%,P =0.000 2）,and the random-effect model was used.The successful rate of thyroid remnant ablation of high dose was statistically significant higher than that of low dose [RR =0.89 （0.81 to 0.97）,P=0.008].Conclusions There is no significant difference in successful rate of thyroid remnant ablation between low and moderate dose treatment,or moderate and high dose treatment in patients after DTC operation.However,high dose is significantly better than low dose.