Comparative efficacy, safety, and oncological outcomes of percutaneous thermal and chemical ablation modalities for recurrent metastatic cervical lymphadenopathy from thyroid cancer.

Background: Thermal and chemical ablation techniques may consolidate recurrent metastatic cervical lymph nodes as alternatives to repeat neck dissection in thyroid cancer patients. This meta-analysis aims to compare the efficacy and safety across modalities.

Methods: Four databases were searched for studies on radiofrequency (RFA), microwave (MWA), laser (LA), and ethanol ablation (EA) treating metastatic cervical nodes from thyroid cancer. The outcomes analyzed included treatment response, oncologic control, and complications. Random effects meta-analytical pooling was conducted.

Results: There were 25 studies (n = 1061 nodes) examining the four ablation methods. Patients showed comparable baseline characteristics and initial lymph node sizes ranging from 0.96 to 1.28 cm. All modalities achieved substantial node volume reduction (88.4 %) and disappearance (62.8 %), with significant biochemical decline (from 6.01 to 1.13 ng/ml, p = 0.18 between groups). MWA showed the highest volume reduction (99.4 %) and disappearance rate (87.6 %) versus slower efficacy of RFA (93.0 %, 72.1 %), LA (77.9 %, 62.5 %), and EA (81.8 %, 58.4 %). New malignancy/metastases risks ranged from 0.03 % to 1.3 % without between-group differences (p = 0.52). Major complications were absent; transient voice changes (0.05%-10.6 %) and neck pain (0.0%-5.9 %) were the main overall complaints. However, overall complication rates significantly varied by modality (1.1%-10.6 %; p = 0.003).

Conclusions: Thermal and chemical ablation is effective in controlling the metastatic disease burden in patients with thyroid cancer, offering a potentially less morbid and non-surgical alternative to re-operation. Additional prospective data could confirm the long-term equivalent of revision neck dissection and stratify patients based on concomitant Hashimoto's and genomic mutations. Clarifying optimal patient selection and standardizing prognostic indexing could further enhance utilization.