Percutaneous ethanol injection of autonomously functioning thyroid nodule.

Percutaneous ethanol injection (PEI) is proposed for treatment of autonomously functioning thyroid nodule, especially for small-mid-sized solitary nodules, for patients refusing the other methods or not proving responsive to radioiodine, or for patients with non toxic nodule. The injection is performed under color Doppler sonography guidance, evaluating the most vascularized areas of the tumor where to primarily inject ethanol solution with 21-22 gauge needles. Serum TSH, FT4, FT3 and TG levels are measured before each treatment session and 3,6,12,24 and 36 months after the end of therapy. Complete remission was achieved by different authors in 86% of cases and the efficacy of response was shown to be inversely proportional to the nodule volume. When TSH remains undetectable, a second cycle of PEI can be performed. If there is complete lack of blood flow signals on color or power Doppler with persisting thyroid hyperfunction, sonographic contrast media can be administered i.v. to assess residual areas of intranodal hypervascularity. In patients with unsuppressed TSH levels before treatment, hormonal changes cannot be used as marker response. Disappearance of nodular hypervascularity at color Doppler sonography and complete normalization of the scintigraphic pattern is usually observed in all cases. PEI is generally well tolerated; no recurrences of the disease and no cases of hypothyroidism have been reported.