1. Thyroid Unit, Hospital de Clínicas de Porto Alegre, Medical School, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
2. Endocrine Oncology Unit and Brazilian National Cancer Institute—INCA, Rio de Janeiro, Brazil.
3. Nuclear Medicine Service, Brazilian National Cancer Institute—INCA, Rio de Janeiro, Brazil.
4. Department of Pharmacology, Institute of Basic Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Federal do Rio Grande do Sul, Brazil.