How to manage the patients with unsatisfactory results after ethanol ablation for thyroid nodules: role of radiofrequency ablation.

Purpose: Although ethanol ablation (EA) is effective in the treatment of cystic thyroid nodules, it is less effective in nodules with solid component. Therefore refractory cases with solid component require another treatment modality such as radiofrequency ablation (RFA), which is effective in both solid and cystic thyroid nodules. We prospectively evaluated the efficacy of additional RFA and factors related to volume reduction in patients showing unsatisfactory results after a single session of EA.

Materials And Methods: Of 94 patients with predominantly cystic thyroid nodules who underwent EA, 20 patients underwent additional RFA because of incompletely resolved clinical problems (symptomatic score reduction <50%) and presence of residual solid component at 1-month follow-up on ultrasonography. Improvement of clinical symptoms and nodule volume reduction were evaluated 6 month later. We evaluated factors related to nodule volume reduction after EA and RFA.

Results: RFA after a single session of EA was effective in reducing mean symptom score from 4.8 to 1.1 (p<0.001), mean cosmetic score from 3.5 to 1.4 (p<0.001) and mean nodule volume from 11.3 to 0.9 mL (p<0.001). The only independent factor related to volume reduction after EA was the presence of a solid component (p<0.001), and EA was less effective in nodules when solid component >20% (p=0.001). We identified no factors related to volume reduction after RFA.

Conclusion: RFA is effective in treatment of benign predominantly cystic thyroid nodules in patients whose clinical problems were incompletely resolved after EA.