Volume 6 Supplement 4
Post-radioiodine management of patients with Graves' disease
© Collins et al; licensee BioMed Central Ltd. 2012
Published: 9 July 2012
Radioiodine is a safe and effective treatment for Graves' disease. Iatrogenic hypothyroidism is very common after treatment, but its onset is unpredictable. Even a short episode of hypothyroidism can result in significant morbidity and ideally should be avoided. In Newcastle a standard dose of radioiodine (400MBq) is used, but for historical reasons two different protocols are used after radioiodine: Regimen A: regular clinical and biochemical monitoring and initiation of levothyroxine when serum thyroid hormones have normalized, and Regimen B: block and replace with Carbimazole and levothyroxine starting 2 weeks post-radioiodine and continuing for 6 months, then withdrawing Carbimazole, but continuing with levothyroxine long-term.
The objective was to compare the two protocols for incidence of biochemical and clinical hypothyroidism during a 12 month post-radioiodine follow-up period and effects on weight gain and development or progression of orbitopathy. Patients with Graves' disease who were treated between January 2008-December 2009 were included. The medical records were reviewed and data were collected and analyzed.
One hundred and twenty two patients were studied, 78 treated with Regimen A and 43 with Regimen B. Euthyroidism at 8 weeks, 6 months and 12 months post-radioiodine was achieved in 50%, 64% and 73% of patients with Regimen A and 65.1%, 71% and 65% in patients with regimen B respectively. Clinical hypothyroidism during follow-up was commoner in Regimen A than B (52.6% vs 16.3% respectively, p<0.05). Weight gain was reported more frequently in Regimen A than B (43.6% vs 20.9%, p<0.05). The incidence of new Graves' orbitopathy developing after radioiodine was higher in Regimen A than B (11.1% vs 5.3%).
A 6 month course of block and replace followed by levothyroxine after a standard 400MBq dose of radioiodine is associated with better clinical outcomes than a watchful approach and initiation of levothyroxine based on biochemical and clinical indicators.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.