Large Benign Thyroid Nodules 101: Ablation vs Surgery
Dr.Guttler’s Comments on this letter to editor.
1. This is the first research reporting the experience of thyroid RFA from the United States.
2. The Koreans state they don’t use general anesthesia. but only local capsule lidocaine.
3. Pain during RFA is tolerable in most patients only using perithyroidal lidocaine injection.
4. Moreover, apart from the usual problems of general anesthesia, monitoring of voice changes by nerve damage during the RFA procedure is impossible under general anesthesia.
5. If voice change is detected during ablation, immediate cessation of RFA and injection of cold dextrose 5% in water (D5W) may recover voice problems induced by thermal damage.
6.Therefore, current RFA guidelines recommend local anesthesia not general.
7. Korean groups have proposed and performed a complete tumor ablation. Two Korean reports of long-term results showed continuous volume reduction over years.8, 9 In a single-center study, Lim et al8 reported 90% volume reduction at 1 year and 93.5% at 4 years. In a multicenter prospective study, Jung et al9 also reported gradual volume reduction over years (80.3% at 1 year, 89.2% at 3 years, and 91.9% at 4 years).
8. However, we should consider the local pain control method for safety.
9.The treatment strategy to achieve reasonable long-term efficacy is total ablation of the nodule even if it requires more than one session.
10. You still need to go to Korea for the best long term results.
I can evaluate you for RFA in Korea or Europe until FDA approval of safe smaller systems.
310-393-8860 or firstname.lastname@example.org.
Richard Guttler MD,FACE,ECNU
Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules
To the Editor: We read with great interest a report by Hamidi et al,1 titled “Outcomes of Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules: A Mayo Clinic Case Series.” Hamidi et al1 presented a retrospective review of 14 patients with predominantly solid thyroid nodules (TNs) treated with radiofrequency ablation (RFA) at the Mayo Clinic. The authors achieved 44.6% of median volume reduction with 8.6 months of the median follow-up period. The clinical efficacy was proved by resolution of compressive symptoms and improvement of cosmetic concerns. There were minor complications (21%) and no reported major complications. They concluded that RFA has an acceptable safety profile and should be considered as a low-risk alternative to conventional treatment of symptomatic benign TNs.
The authors stressed single-session RFA for benign TNs because they achieved acceptable results at 8-month follow-up. In addition, single-session RFA is cost-effective compared with the surgical procedure. However, we should consider the long-term results of thermal ablations (ie, radiofrequency or laser) for benign TNs. In long-term studies with single-session laser ablation (LA), there has been a tendency of marginal regrowth at 2- to 3-year follow-up. Døssing et al6 reported that 35% patients (27 of 78 patients) had thyroid surgery because of an unsatisfactory result 67 months later following LA, mainly due to regrowth of the nodule. Valcavi et al7 reported 9% (11 of 122 patients) recurrence rate at 3-year follow-up. Their volume reduction was maximum at 2 years but slightly decreased at 3 years. It is induced by regrowth of treated nodules. This phenomenon is commonly observed after single-session treatment by LA because tumor regrowth occurs gradually during a follow-up period after an initial improvement of the clinical symptoms. In the single-session study in Mayo Clinic, the authors reported a similar result. In Figure 2, volume reduction at 12 to 24 months was 54.3% but decreased to 52.8% at 24-month follow-up. This result suggests that marginal regrowth started during 12- to 24-month follow-up. In response to this phenomenon, Korean groups have proposed and performed a complete tumor ablation. Two Korean reports of long-term results showed continuous volume reduction over years.8, 9 In a single-center study, Lim et al8 reported 90% volume reduction at 1 year and 93.5% at 4 years. In a multicenter prospective study, Jung et al9 also reported gradual volume reduction over years (80.3% at 1 year, 89.2% at 3 years, and 91.9% at 4 years).
. However, we should consider the pain control method for safety and the treatment strategy to achieve reasonable long-term efficacy.
- Hamidi O, Callstrom MR, Lee RA, et al. Outcomes of radiofrequency ablation therapy for large benign thyroid nodules: a Mayo Clinic case series [published online ahead of print March 21, 2018]. Mayo Clin Proc. https://doi.org/10.1016/j.mayocp.2017.12.011.
- Na, D.G., Lee, J.H., Jung, S.L…., Korean Society of Thyroid Radiology (KSThR), and Korean Society of Radiology. Radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: consensus statement and