Radiofrequency Ablation for Low-Risk T1N0M0 Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis.

OBJECTIVE

To evaluate the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for low-risk T1N0M0 papillary thyroid carcinoma (PTC), with emphasis on T1a versus T1b outcomes and longitudinal volume regression.

MATERIALS AND

METHODS

MEDLINE, EMBASE, Cochrane Library, and KoreaMed databases were searched for studies published between January 2000 and March 2025. Both single-arm and comparative studies were eligible when RFA outcome data could be extracted independently. Thirty-five studies (9,787 tumors) were included in the analysis. Pooled estimates for complete disappearance, persistent tumors, disease progression, and complication rates were calculated using random-effects models. The volume-reduction ratio (VRR) was assessed at sequential follow-up intervals. Subgroup analyses were used to compare the outcomes for T1a and T1b PTCs.

RESULTS

Among the 9,787 RFA-treated tumors, the pooled complete disappearance rate was 87.2% (I² = 97.9%). The pooled persistent-tumor rate was 0.1% (I² = 57.6%), and the pooled disease-progression rate, which reflected newly developed tumors (0.8%; I² = 63.9%) and lymph node metastasis (0.2%; I² = 19.8%), was 1.3% (I² = 70.0%). The VRR increased from 63.4% at 6 months to 88.7% at 12 months and reached 97.9% at 24 months. The pooled complication rate was 2.7% (I² = 93.0%), and the major complication rate was 0.02% (I² = 0%). Subgroup analyses showed lower complete disappearance rates (89.2% vs. 58.8%; P < 0.001) and higher persistent-tumor rates (0.02% vs. 2.2%; P < 0.001) in T1b tumors than in T1a tumors; disease progression (P = 0.234) and total complication rates (P = 0.794) were comparable.

CONCLUSION

US-guided RFA may provide effective tumor control with favorable safety in low-risk T1N0M0 PTC. However, heterogeneity across several efficacy outcomes limits the interpretability of these estimates. T1b PTCs showed lower complete disappearance and higher persistent-tumor rates than T1a PTCs, supporting the need for heightened surveillance of T1b disease.