Advertisement
Mayo Clinic Proceedings Home

In Reply—Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules

      To The Editor: We thank Park and Jung
      • Park A.W.
      • Jung H.B.
      Radiofrequency ablation therapy for large benign thyroid nodules.
      for their pertinent comments regarding our article.

      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.

      They emphasize the use of a transisthmic approach along with a moving-shot technique, both of which we have used, to achieve a safe and effective radiofrequency ablation (RFA) session. In addition, they describe the commonly used approach to anesthesia for RFA—perithyroidal lidocaine injection—and suggest that general anesthesia, as used by us, would not allow monitoring of voice changes during the procedure. To that point they argue that local anesthesia is a safe pain control method that allows voice monitoring and quote
      • Baek J.H.
      • Lee J.H.
      • Sung J.Y.
      • et al.
      Korean Society of Thyroid Radiology
      Complications encountered in the treatment of benign thyroid nodules with US-guided radiofrequency ablation: a multicenter study.
      “only 1% of voice-related complications during RFA of benign nodules” when local anesthesia was used. First, we want to point out that we had no voice-related complications with our approach beyond the periprocedure recovery changes. For safety reasons, we have purposefully left untreated the outer 5 mm of the nodule. This has not been the case with previous RFA protocols. We chose this safety margin because we wanted the complication rate as close to 0 as possible and this has allowed us to treat the nodules safely without continuous monitoring of voice in a patient under anesthesia. Of course, the volume reduction is less, but we think it is worth the added safety benefit. Second, it is pertinent that we dealt with rather large nodules that require an extensive procedure time. For some nodules the patient positioning required for adequately reaching the target nodule is not a very natural one. In this scenario, eliminating patients' anxiety and movement was beneficial for achieving optimal control of the treated area and minimizing risk to adjacent structures. Third, as the submitted commentary points out, “pain during RFA is tolerable in most patients only using perithyroidal lidocaine injection,” which actually underlines the possibility that for some subjects pain will be an issue with local anesthesia and that could lead to discomfort and more so to undesirable movement during the procedure. In response to this issue, we think that there is a role for both approaches to anesthesia, the ultimate selection depending on the size and location of the target lesion as well as the comfort level of the procedural team with the different approaches. The third issue that Park and Jung bring up relates to the comparison between single-session and multisession RFA. We actually did not perform repeat RFA in our study because it was intended to be a small feasibility pilot study. We do agree with their commentary that repeat RFA is likely to achieve further decrease in nodule volume and, in some cases, avoid the need for surgery. However, in most cases, our goal was symptom relief as opposed to maximum volume reduction. With that goal achieved we would consider re-treatment if the nodule regrows and/or is symptomatic. For further research we think that it will be important to identify factors associated with nodule regrowth to properly counsel patients for repeat RFA, while conversely eliminating the need for repeat procedures in those who are very likely to do well after single-session RFA.

      References

        • Park A.W.
        • Jung H.B.
        Radiofrequency ablation therapy for large benign thyroid nodules.
        Mayo Clin Proc. 2018; 93: 1327-1328
      1. 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.

        • Baek J.H.
        • Lee J.H.
        • Sung J.Y.
        • et al.
        • Korean Society of Thyroid Radiology
        Complications encountered in the treatment of benign thyroid nodules with US-guided radiofrequency ablation: a multicenter study.
        Radiology. 2012; 262: 335-342

      Linked Article