Letter to the Editor: Does Thermal Ablation of Thyroid Nodules Increase the Complexity of Subsequent Thyroidectomy?

Dear Editor:

Thermal ablation (TA) is a minimally invasive treatment for thyroid nodules, mainly including radiofrequency ablation (RFA), laser ablation (LA), and microwave ablation. However, certain thyroid nodules treated with TA may still require subsequent surgical intervention, with reports indicating that this proportion can reach as high as 16.4%. Does TA of thyroid nodules increase the complexity of subsequent thyroidectomy? This is a concern raised by many surgeons. To date, there is still limited research on this topic.

We are highly interested in the article titled “Surgical and Pathological Challenges in Thyroidectomy after Thermal Ablation of Thyroid Nodules” published in December 2024. Kuo TC et al. were the first to quantify surgical difficulty using the Thyroidectomy Difficulty Scale (TDS) and macroscopic adhesion score (MAS), comparing the surgical challenges between the ablation and non-ablation groups. ¹ Compared with the nonablation group, the ablation group had longer operative time, higher TDS, and more severe MAS. Ma B et al. conducted a retrospective analysis of primary thyroid cancer patients who underwent thyroid TA at Fudan University Shanghai Cancer Center. ² A total of 12 patients received surgical treatment following TA, and in 6 cases (50%), adhesion between the postablation lesions and the strap muscles was observed. These studies collectively suggest that TA of thyroid nodules may be associated with increased surgical difficulty during subsequent thyroidectomy.

However, other studies have reached different conclusions. Dobrinja C et al. did not observe any adhesions in two patients who subsequently underwent thyroid surgery following RFA, providing the first evidence that RFA does not affect subsequent thyroidectomy. ³ Piana S et al. performed LA on 452 patients with benign thyroid nodules, and 22 patients subsequently underwent thyroidectomy. ⁴ During the procedure, it was observed that thermal injury was confined to the ablation zone, with no involvement of the adjacent parenchyma. In a separate study, only two cases of mild adhesions were observed during subsequent thyroidectomy in 10 patients following RFA, and the surgical difficulty did not increase. ⁵ The studies mentioned above suggest that TA does not complicate subsequent surgical procedures.

We believe that the impact of TA on subsequent thyroidectomy is influenced by several factors. Direct thermal injury to the thyroid capsule and surrounding strap muscles can lead to tissue adhesion, and the postablation inflammatory response may further increase the risk of adhesion. During TA, it is crucial that the active tip of the needle is fully positioned within the nodule or thyroid gland. Improper placement of the needle tip within the thyroid capsule or adjacent muscles may result in thermal injury. In some cases, expanding the ablation zone in malignant nodules may cause damage and adhesion to surrounding muscles. The inflammatory response after TA is most pronounced within the first two months; if surgery is performed during this period, tissue adhesions may complicate the subsequent resection. Further studies are needed to better understand the impact of TA on subsequent thyroidectomy.