Percutaneous ethanol injection versus conservative treatment for benign cystic and mixed thyroid nodules

OBJECTIVE: : To evaluate the efficacy and safety of percutaneous ethanol injection (PEI) in reducing the volume of cystic and mixed thyroid nodules. MATERIALS AND METHODS: : A total of 36 patients with nodules treated with PEI and 13 individuals who declined PEI and were followed clinically or received other non surgical treatment (control group). Assessments were performed at baseline (immediately before treatment in the PEI group or evaluation of the nodule on ultrasonography in the control group) at short-term (on average 30 days after the last injection in the PEI group), and long-term (on average 14 months after baseline in the PEI group or 26 months after baseline in the control group). RESULTS: : In the PEI group, the mean baseline volume of 10.4 ± 9.8 cm(3) reduced at short-term follow-up to 2.9 ± 3.1 cm(3) (67.7 ± 19.9%, p < 0.001) and at long-term follow-up to 2.0 ± 2.5 cm(3) (78.2 ± 19.5%, p < 0.01 versus baseline and p = 0.009 versus short-term follow-up). Both types of nodules showed similar degrees of reduction. In the control group, mean volume was 5.8 ± 3.4 cm(3) at baseline and 6.2 ± 3.0 cm(3) at long-term follow-up (p = 0.507). Compared with the control group, the PEI group showed larger reduction (p < 0.001). CONCLUSIONS: : PEI is effective in reducing the volume of cystic and mixed benign thyroid nodules, with sustained long-term efficacy and better outcome when compared with conservative therapies. Treatment with PEI is a safe alternative, with minimal, transient and self-limited adverse events.