Thermal ablation for radioactive iodine refractory cervical lymph node metastasis in differentiated thyroid cancer.

Abstract

Therapeutic management of radioactive iodine-refractory lymph node metastasis (RAIR-LNM) in differentiated thyroid cancer remains challenging. Thermal ablation for RAIR-LNM has gained a paucity of evidence for clinical guidelines. This multicenter retrospective study analyzed 88 patients with 182 RAIR-LNM at 5 Chinese hospitals between June 2011 and July 2022, to evaluate the effectiveness of thermal ablation for RAIR-LNM. All included patients had at least one ≤ 3 cm RAIR-LNM. The main outcomes were the technical success and disease progression rate. Secondary outcomes included volume reduction rate (VRR), tumor disappearance ratio and the complication rate. Subgroup analyses were performed by using Kaplan-Meier curves and Cox proportional hazards regression models. The mean diameter was 1.35 ± 0.65 cm. The technical success rate was 100% and all elevated thyroglobulin (Tg) levels returned to normal after ablation. Over a mean follow-up period of 55.3 ± 31.39 months, disease progression occurred in 18.18% of patients (16 of 88). Subgroup analysis revealed significantly reduced rates of disease progression (p < 0.05) and new LNM development in patients with Tg ≤ 35 μg/L. Multivariable analysis identified Tg level as a predictor associated with new LNM and disease progression, whereas tumor size and ablation modality showed no statistically significant associations. LNM shrank evidently after ablation, and the disappearance rate was higher for LNM ≤ 1 cm. The overall complication rate was 10.23% (9 of 88). Thermal ablation emerges as a viable therapeutic strategy for RAIR-LNM, offering durable local tumor control and prolonged progression-free survival, especially for patients with Tg < 35 μg/L. Question Whether thermal ablation for radioactive iodine refractory lymph node metastasis could achieve a long-term survival benefit. Findings Reduced rates of disease progression and new lymph node metastasis development were found in patients with thyroglobulin ≤ 35 μg/L. Clinical relevance Thermal ablation serves as a viable therapeutic strategy for patients with radioactive iodine-refractory lymph node metastasis. It offers durable local tumor control and prolonged progression-free survival, especially for patients with lower thyroglobulin levels.