Our results indicate that the use of hTSH increased the efficacy of the RAI therapeutic dose. This was basically due to an increased uptake of the radionuclide (as a consequence of the higher serum TSH levels) and a more extensive distribution of 131I within the nodules of the multinodular goitre. A more intense radiation effect was reflected in there being a higher output of serum Tg and thyroid hormones (group 2). As a consequence this group had a significantly higher reduction of the goitre volume. Also incidence of hypothyroidism post-RAI was significantly higher in group 2. We concluded that pretreatment with rhTSH in elderly patients with large multinodular goitres increases the uptake of the RAI therapeutic dose, thereby significantly reducing the multinodular goitre volume and relieving the compressive symptoms with relatively few side-effects.

The aims of these recommendations were to develop clinical guidelines for evaluation and management of patients with differentiated thyroid cancer applicable to Latin American countries. The panel was composed by 13 members of the Latin American Thyroid Society (LATS) involved with research and management of thyroid cancer from different medical centers in Latin America. The recommendations were produced on the basis of the expert opinion of the panel with use of principles of Evidence-Based Medicine. Following a group meeting, a first draft based on evidences and the expert opinions of the panel was elaborated and, later, circulated among panel members, for further revision. After, this document was submitted to the LATS members, for commentaries and considerations, and, finally, revised and refined by the authors. The final recommendations presented in this paper represent the state of the art on management of differentiated thyroid cancer applied to all Latin American countries. Arq Bras Endocrinol Metab. 2009;53(7):884-97. KeywordśThyroid cancer; thyroid ultrasonography; radioiodine therapy; thyroglobulin; consensus RESUMO Estas recomendações tiveram por objetivo o desenvolvimento de diretrizes para avaliação e manejo de pacientes com câncer diferenciado da tiroide em países latino-americanos. Um painel composto por 13 membros da Sociedade Latino-Americana de Tireoide (SLAT) -que estavam envolvidos em pesquisas, e eram peritos no cuidado do paciente com câncer da tiroide e provenientes de diferentes centros médicos latino-americanos -utilizou os princípios da Medicina Baseada em Evidências para produzir esse consenso. Após uma primeira reunião, um texto inicial foi elaborado, baseado em evidências e opiniões dos especialistas do painel e, posteriormente, circulado entre os membros do painel, para revisão. Após a revisão, o documento foi enviado aos membros da SLAT para comentários e considerações e, finalmente, revisado e refinado pelos autores. As recomendações finais aqui apresentadas demonstram o estado da arte no manejo do câncer diferenciado da tireoide aplicadas aos países latino-americanos.Arq InTRODUCTIOn T he risk of malignancy in a thyroid nodule varies between 5% and 10% in iodine sufficient countries, and the amount of iodine supplemented in table salt influences on the morphology of the malignant tumor types (1).

Objective: To evaluate the prevalence of chronic autoimmune thyroiditis (CAT) and iodine-induced hypothyroidism, hyperthyroidism (overt and subclinical), and goiter in a population exposed to excessive iodine intake for 5 years (table salt iodine concentrations: 40-100 mg/kg salt). Design: This was a population-based, cross-sectional study with 1085 participants randomly selected from a metropolitan area in São Paulo, Brazil, and conducted during the first semester of 2004. Methods: Thyroid ultrasound examination was performed in all participants and samples of urine and blood were collected from each subject. Serum levels of thyroid-stimulating hormone, free thyroxine, and anti-thyroid peroxidase (TPO) antibodies, urinary iodine concentration, thyroid volume, and thyroid echogenicity were evaluated. We also analyzed table salt iodine concentrations. Results: At the time the study was conducted, table salt iodine concentrations were within the new official limits (20-60 mg/kg salt). Nevertheless, in 45.6% of the participants, urinary iodine excretion was excessive (above 300 mg/l) and, in 14.1%, it was higher than 400 mg/l. The prevalence of CAT (including atrophic thyroiditis) was 16.9% (183/1085), women were more affected than men (21.5 vs 9.1% respectively, PZ0.02). Hypothyroidism was detected in 8.0% (87/1085) of the population with CAT. Hyperthyroidism was diagnosed in 3.3% of the individuals (36/1085) and goiter was identified in 3.1% (34/1085). Conclusions: Five years of excessive iodine intake by the Brazilian population may have increased the prevalence of CAT and hypothyroidism in subjects genetically predisposed to thyroid autoimmune diseases. Appropriate screening for early detection of thyroid dysfunction may be considered during excessive nutritional iodine intake.European Journal of Endocrinology 159 293-299

We prospectively evaluated the effect of thyrotropin (TSH)-suppressive therapy with levothyroxine (LT4) on the size of a benign, solitary, solid nodule and multinodular goiter in a relatively low iodine intake area. In this study, 101 euthyroid subjects with a benign, solitary, predominantly solid nodule (n = 54) confirmed by biopsy or multinodular goiter (n = 47) received 200 microg of levothyroxine daily as a single morning tablet for 12 months. Thirty-five receiving no therapy were considered as controls (solitary nodules, n = 20, multinodular, n = 15). Patients were admitted to the study after evaluation of thyroid biochemical parameters (thyroxine [T4], free thyroxine [FT4], triiodothyronine [T3], thyrotropin [TSH], and thyroglobulin [Tg]), thyroid scanning, ultrasound examination, and fine-needle aspiration biopsy. Every 3 months, thyroid function tests and every 6 months ultrasound examinations were repeated. Twelve months later 20 of 54 (37.1%) patients with single, solid nodules had 50% or more regression of the nodular volume (responders). Eleven of 54 (20.3%) patients had more than 20%, but less than 49.9% reduction of nodular volume (partial responders). Nonresponders were 23 of 54 (42.5%). One-third of subjects with multinodular goiter had 50% or more regression of the glandular volume, whereas 46.8% were considered as nonresponsive. The mean serum Tg levels decreased significantly only in responders with solitary nodular disease or multinodular goiter. In the control group only 1 patient (5% of total) with a solitary nodule had a 50% reduction in the nodular volume. Five others had a partial response (<49%, >20% reduction). None of the patients with multinodular goiter had a significant reduction (>50%) of the combined nodular volumes. We concluded that LT4 may be effective, among other factors, in arresting the growth or in reducing the volume of relatively small, benign, solitary, solid thyroid nodules or the combined nodular volume of multinodular goiter.