Comparison Between Radioiodine Therapy and Single-Session Radiofrequency Ablation of Autonomously Functioning Thyroid Nodules

A Retrospective Study

Rosa Cervelli; Salvatore Mazzeo; Giuseppe Boni; Antonio Boccuzzi; Francesca Bianchi; Federica Brozzi; Pierina Santini; Paolo Vitti; Roberto Cioni; Davide Caramella


Clin Endocrinol. 2019;90(4):608-616. 

In This Article


Patients' Data

The baseline characteristics of the patients and nodules, grouped by the treatment received, are summarized in Table 1. A statistical comparison of these characteristics was performed in order to verify the absence of statistical difference between the two groups, as shown by the p value. In the RI group, 16/25 patients showed AFTN in the toxic phase and reported symptoms such as palpitation and hand tremor, whereas in the RFA group thyrotoxicosis was present in 12/22 patients. Before RI, the ATD was administered in 13/16 patients in the toxic phase, while before RFA all the 12 patients underwent ATD therapy. The ATD drug administered in all cases was methimazole and its starting dosage ranged from 5 to 15 mg, according to the severity of the hyperthyroid state. Two out of 25 patients treated by RI and 3/22 treated by RFA were positive for TPOAb or TgAb.

Treatment Outcomes

The treatment outcomes for the two groups at the 12-month follow-up are summarized in Table 2. As to the volume reduction end-point, the mean post-RI volume of the nodule was 4.95 ± 8.2 mL, with volume reduction rate (VRR) of 68.4 ± 28.9%, whereas post-RFA volume of the nodule was 2.6 ± 2.1 mL, with VRR of 76.4 ± 16.9%. By comparing RI and RFA, no statistical difference was found either between the post-treatment nodule volume (P = 0.62) and the VRR (P = 0.63).

As to the thyroid function end-point, after RI therapy, all the 25 patients silenced the hyperfunctioning thyroid nodules. Five patients developed clinical hypothyroidism requiring levothyroxine (LT4). The remaining 20 patients normalized their fT3 and fT4 values (success rate of 80%); among them 18 showed euthyroidism, whereas in 2/20 patients the THS values were slightly over-range (sub-clinical hypothyroidism). The characteristics of the 5 patients with whom RI determined undesirable effects (clinical hypothyroidism) are reported in Table 3.

After RFA, all the 22 patients silenced their hyperfunctioning thyroid nodule and normalized the fT3 and fT4 values with a success rate of 100%. Two out 22 patients showed sub-clinical hypothyroidism (TSH value of 6.7 microUI/mL and 4.9 microUI/mL, respectively, associated with fT3 and fT4 in the normal range). Both patients were affected by thyroiditis: one of them was diagnosed "Hashimoto's thyroiditis (with positive TPOAb)," whereas the other suffered from nonspecific thyroiditis, characterized by reduced volume of the thyroid gland, low vascular signal by EchoColor Doppler and hypoechoic texture by B-mode US evaluation.

Finally, as to complications, no patients experienced any minor or major complication in both groups.