Radiofrequency Ablation for Amiodarone-induced Thyrotoxicosis

Investigators plan to identify patients with amiodarone-induced thyrotoxicosis (AIT) that
failed to respond to medical therapy or have developed side effects from medical therapy or
are considered high risk for such therapy.

These patients will be offered the option to undergo radiofrequency ablation (RFA) of a
portion of the thyroid gland in order to decrease thyroid hormone production and/or to
inactive the existing thyroid hormone store before their leakage into the circulation.

Investigators will follow these patients to assess their clinical response as well as their
thyroid values. The safety of the procedure will also be assessed.

Inclusion Criteria:

- Are adults

- Have overt thyrotoxicosis (within 2 weeks prior to enrollment)

- Are receiving medical therapy for AIT

- Are able to understand the study procedures and to comply with them for the entire
length of the study

- Have not normalized their thyroid levels after one month of standard therapy or

- Have persistent and clinically significant thyrotoxicosis (less than 25% decrease in
T4 value or patients requiring hospitalization with CHF, tachyarrhythmias, hemodynamic
instability or similar co-morbidities) after 2 weeks of standard therapy where
additional medical therapy is deemed unlikely to be beneficial or with high risk of
side-effects (e.g. hepatotoxicity of antithyroid medications, agranulocytosis of
potassium perchlorate or ATD or fluid retention associated with steroids).

Exclusion Criteria:

- Pregnancy

- Patients with prior neck surgery or neck radiation

- Patients with neck anatomy that precludes easy access by RFA to the entirety of
thyroid parenchyma

- Patients on anticoagulation therapy

- Patients with comorbidities deemed too high of a risk for general anesthesia

- Treatment with another investigational drug or intervention (within 6 weeks of planned
RFA).

- Current drug or alcohol use or dependence that, in the opinion of the site
investigator, would interfere with adherence to study requirements.

- Inability or unwillingness of individual or legal guardian/representative to give
written informed consent.