Low iodine diet does not improve the efficacy of radioiodine for the treatment of Graves' disease

ABSTRACT Objective: Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine ( 131 I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves' disease (GD) treated with 131 I. Subjects and methods: We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). Results: The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism's cure between the LID and the RD groups 6 months after 131 I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: < 10 μg/dL is deficient; 10-29.9 μg/dL is sufficient; and > 30 μg/dL is excessive). Conclusion: In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of 131 I for the treatment of GD. Arch Endocrinol Metab. 2015;59(6):501-

Contribuição da medicina nuclear para a avaliação dos linfomas

A medicina nuclear permite a caracterização funcional de tecidos, acrescentando dados à avaliação anatômica realizada por outros métodos de imagem, como a tomografia computadorizada, ressonância magnética ou ultra-som. Além do diagnóstico e estadiamento, as informações funcionais fornecidas pela medicina nuclear são particularmente úteis no seguimento e avaliação de resposta terapêutica dos pacientes com linfoma. A presença de massa residual após quimioterapia ou a infiltração de linfonodos de pequenas dimensões são exemplos de situações nas quais a avaliação isolada de características anatômicas é insuficiente. Os principais métodos utilizados são a cintilografia com gálio-67, traçador com alta afinidade por transferrina e receptores de ferro, e os estudos com flúor-deoxiglicose, emissor de pósitron que permite a caracterização do metabolismo de glicose nos tecidos. Outros traçadores, como o tálio-201, sestamibi-Tc99m e octreotide-In111, também são utilizados em menor escala na avaliação dos pacientes com linfoma. Os mecanismos de captação, principais indicações dos estudos, limitações e resultados de literatura serão revistos

Low iodine diet does not improve the efficacy of radioiodine for the treatment of Graves’ disease

Objective Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves’ disease (GD) treated with131I. Subjects and methods We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). Results The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism’s cure between the LID and the RD groups 6 months after 131I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: 30 μg/dL is excessive). Conclusion In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of131I for the treatment of GD