Comparison of Different Doses of 131I in Severe Graves' Hyperthyroidism
The purpose of this study is to determine whether higher doses of radioiodine increase treatment efficacy in severe Graves' disease.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Comparison of Different Doses of 131I in Severe Graves' Hyperthyroidism: A Clinical Trial With Historical Control|
- Cure, defined as euthyroidism or permanent hypothyroidism based on FT4 measurements. [ Time Frame: 12 months ] [ Designated as safety issue: No ]
- Euthyroidism [ Time Frame: 12 months ] [ Designated as safety issue: No ]
- Permanent hypothyroidism [ Time Frame: 12 months ] [ Designated as safety issue: No ]
|Study Start Date:||February 1997|
|Study Completion Date:||August 2011|
|Primary Completion Date:||August 2011 (Final data collection date for primary outcome measure)|
Active Comparator: Radiodine-200µCi
A subgroup of patients with Graves' Disease and goiter ≥48ml treated with 200µCi of ¹³¹I/ml thyroid tissue, corrected by 24h-RAIU, from a randomized controlled trial run at our institution between February 1997 and March 2000, serves as a historical control.
A unique dose of 200µCi of ¹³¹I/ml/24-RAIU
Patients with Graves' Disease and goiter ≥48ml, prospectively assigned to receive 250 µCi of ¹³¹I/ml thyroid tissue, corrected by 24h-RAIU.
A unique dose of 250µCi of ¹³¹I/ml/24-RAIU
Graves' disease (GD) is the most frequent cause of hyperthyroidism, affecting mainly women aged 40-60 years. Radioiodine (¹³¹I), introduced in 1941, has become a cornerstone in the treatment of GD hyperthyroidism. Because of its safety, low costs and rapid effect, it is considered a first line therapy in the United States. However, treatment failure occurs in about 15-25% of patients treated with radioiodine. Patients not cured with the first dose of radioiodine usually present severe hyperthyroidism, characterized by large goiter, high 24-hour radioiodine uptake (24h-RAIU) and very high levels of thyroid hormones. We have previously shown that large goiter (≥48ml) is an independent predictor of treatment failure. In these patients, the therapeutic failure was 40.0% while in patients with smaller goiter was only 6.5% (P=0.005; unpublished). It is generally accepted that higher doses of radioiodine improves cure rates. Indeed, a recent meta-analysis found a correlation between radioiodine dose and therapeutic success in GD patients. To our knowledge, there are no published studies evaluating cure rates with different radioiodine doses in severe GD.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01039818
|Thyroid Unit, Endocrine Division, Hospital de Clínicas de Porto Alegre|
|Porto Alegre, RS, Brazil, 90035-003|
|Principal Investigator:||Ana L Maia, MD, PhD||Thyroid Unit, Endocrine Division, Hospital de Clínicas de Porto Alegre|