Introduction

Toxic thyroid nodules are usually treated with radioactive iodine. This is associated with a high risk of permanent hypothyroidism. Radiofrequency ablation (RFA) may be a good alternative.

Aim

To study the efficacy and adverse effects of RFA in patients with symptomatic toxic thyroid nodules.

Patients and Methods

Patients with a symptomatic toxic thyroid nodule, documented by suppressed TSH levels and a hot nodule on I¹²³ scan were treated with ultrasound-guided RFA, after local anesthesia, and in an outpatient setting. RFA was performed by the transisthmic approach. Follow-up was at least one year.

Results

Twenty-one patients (20 women, one man) were included, ranging in age from 37 – 75 years. Four patients received antiarrhythmic treatment for chronic atrial fibrillation. All subjects had suppressed TSH levels, eight had mildly elevated FT4 levels, and five had a mildly elevated FT3. RFA was not associated with clinically significant adverse effects. Euthyroidism was achieved in 11/21 patients (52%). A partial response with normalization of FT4 and FT3, and an incomplete improvement of TSH levels was observed in 6/21 patients (29%). Three patients had no response (14%), and one patient developed mild, but permanent hypothyroidism, that was treated successfully with levothyroxin 25 ug per day. Three patients underwent a second RFA treatment and this led to euthyroidism in all three, thereby raising the rate of complete remission to 67%. Recurrence of hyperthyroidism has not been observed so far.

Conclusion

These data suggest that radiofrequency ablation is a safe and promising treatment for symptomatic toxic thyroid nodules, with a low risk of permanent hypothyroidism. Current follow-up is too short to establish the recurrence risk of hyperthyroidism.