Thermal Ablation Versus Thyroid Lobectomy for Subcapsular Papillary Thyroid Microcarcinoma: A Multicenter Retrospective Study.

OBJECTIVES

To compare the efficacy of thermal ablation (TA) with thyroid lobectomy (TL) for clinical node-negative subcapsular papillary thyroid microcarcinoma (PTMC) and to assess the impact of occult lymph node metastasis (LNM) or pathologic local invasion on clinical outcomes.

METHODS

This retrospective study was conducted at 3 referral centers. It included patients with unifocal clinical node-negative subcapsular PTMC who underwent TA (n = 536) or TL (n = 740) from June 2014 to December 2020. The TL group was divided into occult LNM-positive, occult LNM-negative, pathologic local invasion-positive, and pathologic local invasion-negative subgroups based on pathologic findings. Propensity score matching and inverse probability of treatment weighting were used to control for potential confounders. Primary outcomes were disease progression and progression-free survival (PFS). Secondary outcomes included complications and treatment parameters.

RESULTS

The median follow-up duration of the primary cohort was 60.1 (42.0) months. After propensity score matching (519 patients per group), no significant differences were observed in disease progression rates (4.0% vs 2.7%) or 5-year PFS rates (95.8% vs 97.2%) between the TA and TL groups (P > .05). After inverse probability of treatment weighting, the TA group exhibited no significant difference in PFS rates compared to the occult LNM-positive (P = .97) or the pathologic local invasion-positive (P = .66) subgroups. Additionally, TA was associated with lower complication rates compared with TL (0.4% vs 2.1%, P = .01)

CONCLUSIONS

In eligible patients with subcapsular PTMC, TA and TL exhibit comparable 5-year disease progression rates and PFS rates. TA may be an alternative option for eligible patients with subcapsular PTMC who are ineligible for or refuse lobectomy.