Efficacy and safety of cooled and uncooled microwave ablation for the treatment of benign thyroid nodules: a systematic review and meta-analysis

Abstract

Purpose: To evaluate the effectiveness and safety of microwave ablation (MWA), including cooled MWA (cMWA) and uncooled MWA (uMWA), for the treatment of benign thyroid nodules (BTNs).

Methods: The databases of MEDLINE, EMBASE and Cochrane library were searched up to 3 Jun, 2018. In this meta-analysis, data of volume reduction rates (VRRs) at the 3-, 6- and 12-month follow-up, and complications are obtained to evaluate the effectiveness and safety of cMWA and uMWA for the treatment of BTNs.

Results: Nine studies involving 1461 patients with 1845 BTNs were included. The pooled VRR at the 3-month follow-up after MWA therapy reached 54.3% (95% CI: 45.3-63.3%, I² = 97.6%), 73.5% (95% CI: 66.7-80.3%, I² = 94.9%) at the 6-month follow-up, and 88.6% (95% CI: 84.9-92.4%, I² = 92.7%) at the 12-month follow-up. The pooled proportions of overall, major and minor complications were 52.4% (95% CI: 29.8-74.9%; I² = 99.5%), 4.8% (95% CI: 2.7-7.0%; I² = 55.9%) and 48.3% (95% CI: 31.2-65.4%; I² = 99.7%). Both cMWA and uMWA achieved similar pooled VRR at the 3-month follow-up (58.4 vs 45.3%, P = 0.07) and pooled proportion of major complications (4.9 vs 5.0%, P = 0.49), while uMWA had higher pooled proportions of overall and minor complications than cMWA (97.8 vs 29.7%, P < 0.01; 97.8 vs 21.0%, P < 0.01), with more patients suffering pain and skin burn after uMWA (100 vs 5.5%, P < 0.01; 47.2 vs 0.2%, P < 0.01).

Conclusion: MWA is an effective treatment modality for BTNs. When considering the patient's comfort, cMWA would be a more preferable procedure with less complications.

Keywords: Meta-analysis; Microwave; Thyroid nodule.