Minimally invasive procedures such as laser ablation (LA) are gaining ground in modern surgery to reduce post-operative changes in quality of life. This encouraged the exploration of the applicability of LA in patients with papillary thyroid cancer (PTC), therefore, we aimed to evaluate the feasibility and histological effect of LA in patients with PTC.

Patients with cytologically suspected or confirmed thyroid carcinoma - Bethesda grades V-VI - were included in the study. Before thyroidectomy, thyroid nodules were evaluated ultrasonographically for the suitability of safe and effective LA. Suitable patients underwent LA followed by thyroidectomy. Specimens with ablated tissue, residual tumor, and unaffected parenchyma were measured and evaluated using triphenyl tetrazolium chloride (TTC) solution, histologic (hematoxylin and eosin), and immunohistochemical methods (using NADPH oxidase 4). If patients were not eligible for LA, the reason was documented, and a thyroidectomy was performed.

From 7th February till 1st December 2023, 16 patients have been enrolled in the study. 6 of them (37.5%) were eligible for LA. Macroscopic and microscopic examination of the lobes revealed an LA-induced central carbonization zone, alongside TTC-negative, NADPH4-negative coagulative changes in the residual tumour. Unaffected thyroid tissue retained normal histology, TTC- and NADPH4 positivity.

To our knowledge, this is the first study that demonstrates laser ablation-induced irreversible histochemical changes in papillary thyroid carcinomas. Ongoing trial will collect important data on LA feasibility, patient selection, and appropriate LA procedure parameters.