Radiofrequency ablation for treatment of benign thyroid nodules: A PRISMA-compliant systematic review and meta-analysis of outcomes

Abstract

Background: Thyroid nodules (TNs) usually appearing in the general population have the potential possibility of malignant transformation and common problems of jugular oppression such as dyspnea and hoarseness. We performed this meta-analysis to evaluate the efficiency of radiofrequency ablation (RFA) for the treatment of benign TNs in accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements.

Methods: Published literatures were retrieved from PubMed, Embase, Web of Science, and Scopus up to January 27, 2016. Pooled standard mean difference with 95% confidence interval was estimated by fixed- or random-effects model depending on heterogeneity, which was calculated using the Cochran Q, τ, and I statistics. The quality of the articles was evaluated by the Newcastle-Ottawa scale.

Results: Meta-analysis of data from 1090 patients with 1406 benign TNs in 20 articles showed that with the subgroup stratified by nodule volume, they were significantly decreased at 1, 3, 6, 12, and the last follow-up months, when comparing post-RFA with the initial nodule volume. In addition, the volume also notably declined by cold and hot nodules. By subgrouping into the largest diameter, symptom score, cosmetic score, thyrotropin, triiodothyronine, free thyroxine level, and vascularity, the pooled data indicated that there was a decrease in largest diameter, symptom score, cosmetic score, triiodothyronine level, and vascular scale, an unchanged free thyroxine, and an increased thyrotropin level after RFA. The publication bias for this particular study is presented in the following groups: nodule volume reduction at 6 months and last follow-up month after RFA and symptom score.

Conclusion: In summary, by pooling of these studies we recommended that RFA indeed has the advantages in improving outcomes and providing better prognosis for patients with benign TNs.

Figure 1

Flow diagram of the study selection process.

Figure 2

Volume changes of benign TNs before and 1 month (A), 3 months (B), 6 months (C), and 12 months (D) after RFA treatment. Compared with preoperative TN volume, the postoperative volume shows the decreased response at 1, 3, 6, and 12 months after RFA treatment. CI = confidence interval, RFA = radiofrequency ablation, SMD = standardized mean difference, TN = thyroid nodule.

Figure 3

Volume changes of benign TNs before and last follow-up month after RFA treatment. Compared with preoperative TN volume, the postoperative volume indicates the reduced response at the last follow-up month after RFA treatment among overall benign TNs (A) and hot and cold nodules (B). CI = confidence interval, RFA = radiofrequency ablation, SMD = standardized mean difference, TN = thyroid nodule.