Comparison of Different Doses of 131I in Severe Graves' Hyperthyroidism

Sponsor

Hospital de Clinicas de Porto Alegre (Other)

Overall Status

Completed

CT.gov ID

NCT01039818

Collaborator

Federal University of Rio Grande do Sul (Other)

Enrollment

Location

Arms

173.9

Duration (Months)

0.2

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of this study is to determine whether higher doses of radioiodine increase treatment efficacy in severe Graves' disease.

Condition or Disease	Intervention/Treatment	Phase
Graves Disease	Radiation: Radioiodine Radiation: Radioiodine	Phase 3

Detailed Description

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 In these patients, the therapeutic failure was 40.0% while in patients with smaller goiter was only 6.5% (P=0.005; unpublished).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.

Study Design

Study Type:

Interventional

Actual Enrollment :

30 participants

Allocation:

Non-Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Comparison of Different Doses of 131I in Severe Graves' Hyperthyroidism: A Clinical Trial With Historical Control

Study Start Date :

Feb 1, 1997

Actual Primary Completion Date :

Aug 1, 2011

Actual Study Completion Date :

Aug 1, 2011

Arms and Interventions

Arm	Intervention/Treatment
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.	Radiation: Radioiodine A unique dose of 200µCi of ¹³¹I/ml/24-RAIU
Experimental: Radiodine-250µCi Patients with Graves' Disease and goiter ≥48ml, prospectively assigned to receive 250 µCi of ¹³¹I/ml thyroid tissue, corrected by 24h-RAIU.	Radiation: Radioiodine A unique dose of 250µCi of ¹³¹I/ml/24-RAIU

Arm

Intervention/Treatment

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.

Radiation: Radioiodine

A unique dose of 200µCi of ¹³¹I/ml/24-RAIU

Experimental: Radiodine-250µCi

Patients with Graves' Disease and goiter ≥48ml, prospectively assigned to receive 250 µCi of ¹³¹I/ml thyroid tissue, corrected by 24h-RAIU.

Radiation: Radioiodine

A unique dose of 250µCi of ¹³¹I/ml/24-RAIU

Outcome Measures

Primary Outcome Measures

Cure, defined as euthyroidism or permanent hypothyroidism based on FT4 measurements. [12 months]

Secondary Outcome Measures

Euthyroidism [12 months]
Permanent hypothyroidism [12 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 65 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Consecutive patients with a recent diagnosis of Graves' disease and goiter ≥ 48 ml, attending the Endocrine Division at Hospital de Clinicas de Porto Alegre are eligible.

Exclusion Criteria:

Patients with previous treatment with radioiodine or thyroidectomy,
Signs of moderate or severe ophthalmopathy (proptosis > 22 mm, ophthalmoplegia, chemosis, or lagophthalmos),
Severe heart disease (symptomatic coronary heart disease, class III heart failure, New York Heart Association criteria),
Debilitating conditions, and
Large and compressive goiters (> 150 g).