Data from South America related to the use of radioiodine
therapy indicate that radioiodine is prescribed only by physicians with special training and a license. A thyroid dose of 131I > 29 mCi requires hospitalization of the patient. Members of the Latin American Thyroid Society (
LATS) (235 physicians) were surveyed by a questionnaire on their management of
Graves' disease, and the survey procedure was the same used by the other thyroid societies. Thyroid uptake/scintigraphy was carried out by 60% of respondents and 131I was the
isotope most used (chosen by 95% of respondents). Serum total T4 and T3 were requested by 97%, of
LATS members whereas measurement of free T4 and TSH was employed less frequently (27% and 46.3%, respectively). The
therapy of choice for 83% of responding members was
antithyroid drugs. Radioiodine was chosen by 15.3% of respondents. For most respondents, the aim of 131I
therapy was to restore euthyroidism. It was based on
goiter size and thyroid uptake and administered in a single dose. For the radioiodine
therapy, 55.5% of the respondents did not add any other medical treatment. The remaining group used
antithyroid drugs before 131I (50%), and 77% employed it after the dose. There is a general consensus to provide the 131I treatment only to patients > 18 years of age. 131I was overwhelmingly (64.2% versus 34% of
drug therapy) the
therapy seen as most appropriate for patients with recurrence or old age. The predominant use of
antithyroid drugs for
therapy of
Graves' disease in South America was similar to that in Europe and Japan but different from the practice in North America.