Treatment of hyperfunctioning thyroid nodules with percutaneous ethanol injection: Eight years' experience

The aim of our study was to define the long-term efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of autonomous thyroid nodule (ATN), and to optimise the clinical usefulness of such a therapy. We treated 132 patients with ATN (30 M and 102 F, aged 47.5+/-12.9 years; mean+/-SD), in case other established treatments were refused or contraindicated. Eighty-five patients were affected by toxic adenoma and 47 suffered from pre-toxic nodules. Ethanol was administered weekly under sonographic control, in 7 sessions (range 2-16). During PEI treatment, 26 toxic elderly patients were treated with methimazole and propranolol. Three possible outcomes were identified for statistical analysis: failure (persistent suppression of extra nodular tissue uptake, along with elevated free thyroid hormone and undetectable TSH levels); partial cure (normal free thyroid hormone and low/undetectable TSH levels); complete cure (normal thyroid hormone and TSH levels; restored extra nodular uptake). The patients were followed for up to 8.5 years (median 76 months). PEI therapy was well tolerated by all patients though a mild to moderate local pain occurred in about 30% of sessions. Complete cure was achieved in all pre-toxic patients and in 60 (70.6%) patients with toxic adenoma, while partial cure was observed in 11 cases (12.9%) and failure in 14 (16.5%). A significant shrinkage of nodule volume was observed in all patients (p = 0.0001), while those with toxic nodules larger than 30 mL showed a significantly lower response rate to PEI (p < 0.05). At controls, only one patient developed subclinical hypothyroidism while, among partially cured patients, five relapsed. The administration of methimazole and/or propranolol did not modify PEI outcome. In conclusion, we suggest that PEI therapy may be the treatment of choice in patients with pre-toxic thyroid adenoma where therapy is least necessary- despite the nodule volume. Though ethanol injection therapy of toxic thyroid nodules may be troublesome for the need of multiple sessions, it appears an effective alternative procedure in patients at poor surgical risk, and in younger patients in whom radioiodine is contraindicated. Since a special technical skill in intervention procedures is required, PEI therapy may be suitable only for patients living nearby a trained centre.