SUN-LB83 Outpatient Radiofrequency Ablation Is a Safe and Effective Treatment Option for Benign Thyroid Nodules in North America

Background: Radiofrequency ablation (RFA) of thyroid nodules is a non-mainstream treatment option for benign thyroid nodules. Studies in Asia and Europe (1) have demonstrated RFA to be an effective outpatient alternative to surgery, however, these results have not been reproduced in North America. Hypothesis: RFA of symptomatic benign thyroid nodules can reduce morbidity associated with thyroidectomies, without sacrificing favorable clinical outcomes. Methodology: A retrospective review of 11 patients (all female and Caucasian) with 13 thyroid nodules treated with RFA in our practice was conducted (Nov 2018 - Oct 2019). The 9 nontoxic nodules were biopsied twice, and 4 toxic adenomas were biopsied once; all had benign cytopathology results prior to RFA. RFA was done under local anesthesia/conscious sedation, with follow-up telephone call after 2 days to assess complications (pain, voice change, hematoma/swelling, skin burns). Nodule volume in mL (length x depth x width in cm x 0.525), cosmetic score (2), and thyroid function tests (TSH and free T4) were recorded pre-procedure, and 6 - 10 weeks post procedure. The volume reduction rate (VRR) was calculated as follows: [(baseline volume - final volume)/baseline volume] x 100 (%). Results: The mean age of the patients was 45 years; 7 were euthyroid (not on thyroid hormone replacement), and 4 had hyperthyroidism. The mean volume of treated thyroid nodules decreased from 12.3 cc to 5.6 cc, with a mean VRR of ~ 54%. Thyroid nodules with volumes less than 10 cc (smaller) had a VRR of ~ 75%, whereas nodules with volumes more than 10 cc (larger) had a VRR of ~ 50%. The VRR between smaller and larger nodules (p-value: 0.11), and toxic adenomas and nontoxic thyroid nodules (p-value: 0.26), was not significantly different. 3 out of 4 patients with toxic adenomas normalized their TSH levels; 1 patient normalized free T4 levels, but TSH remained suppressed. None of the patients developed hypothyroidism. The cosmetic scores (indicating visible or palpable mass) improved by 50%. All patients had complete resolution of compressive symptoms. Minimal discomfort only reported at time of procedure. No complications were reported at the 2-day, or the 6-10-week follow-up. Conclusions: Outpatient RFA is a safe and effective treatment for benign thyroid nodules and toxic adenomas. There were no complications in our study, however, this may be limited by the small sample size and relatively short follow-up duration. Advantages of RFA include avoiding lifelong thyroid hormone replacement and complications of surgery and/or general anesthesia. We propose that RFA be considered as a first-line therapy for the treatment of benign thyroid nodules for these reasons. References: (1) Feldkamp, et al. Exp Clin Endocrinol Diabetes. 2020 Jan 7. doi: 10.1055/a-1075-2025. (2) Dobnig, et al. Thyroid. 2018 Apr;28(4):472-480. doi: 10.1089/thy.2017.0547.