Role of radiofrequency ablation in the treatment of symptomatic distant metastasis of thyroid cancer

Objective: To evaluate the effectiveness and safety of radiofrequency ablation (RFA) for the treatment of symptomatic distant metastasis of differentiated thyroid carcinoma.

Materials and methods: The medical records of 12 patients who underwent RFA for the palliative treatment of 18 symptomatic distant metastases from thyroid cancer between January 2008 and December 2020 were analyzed. All patients were assessed for their degree of discomfort and underwent periodical evaluations as outpatients, including clinical examination, imaging, and serologic markers.

Results: Among the 18 tumors treated, nine were soft tissue, and nine were bone metastases. The mean size of the treated tumors was 5.3 cm (range, 1.7-10.7 cm). All patients complained of pain, discomfort and/or bulging of the metastatic mass before RFA. After RFA, 11 out of the 18 patients with metastatic tumors (61.1%) reported a subjective improvement in symptoms. Nine out of 18 tumors decreased in size, with a mean size reduction ratio of 43% ± 22%. Although symptom improvement was achieved in 61.1% of the tumors, after a mean follow-up duration of 37.4 months, five patients experienced progression of the tumor, four patients had a stable tumor status, and three patients died from pneumonia. There were no major adverse events related to RFA during the treatment or follow-up period.

Conclusion: RFA can be used as palliative therapy to relieve the symptoms caused by metastatic tumors; however, it has a limited role in improving the overall prognosis in patients with distant metastasis from thyroid cancer.