An Assessment of the Occurrence of Hypothyroidism in Patients Treated With RAI for Hyperthyroidism.

An Assessment of the Occurrence of Hypothyroidism in Patients Treated With RAI For Hyperthyroidism, And it's Prognostic Factors.

Low RAIU in patients with hyperthyroidism represents a common obstacle in the treatment with RAI. Therefore, a higher dose of RAI must be administered to cure hyperthyroidism in these patients. If we treat patients with thiamazole before starting RAI treatment, serum TSH will rise and result in an increase in iodine uptake by the thyroid gland. By doing so, the dose of RAI to be administered might be lowered to achieve similar therapeutic efficacy.

In the past, either calculated or fixed doses of 131I have been used to treat hyperthyroidism. The supposed advantage of a calculated dose compared to a fixed dose is the lowering of hypothyroidism frequency. However, various research papers have contradicted this statement.

Antithyroid drugs and RAI therapy have been widely used in the past, either in combination, or independent from one another. This has been done primarily in older patients, to reduce the risk of exacerbation of hyperthyroid symptoms after initiation of RAI.

The use of propylthiouracil has been shown to decrease the response rate after RAI due to radioprotective effects.

The use of methimazole and carbimazole did not have a negative effect on treatment failure, as long as the medication was discontinued various days before RAI administration. Although this statement is contested in other studies.

It is interesting to evaluate retrospective data of patients treated with RAI to evaluate prognostic factors of treatment respons and post RAI hypothyroidism.

Study Overview

• Status: Active, not recruiting
• Conditions: Nodule Solitary Thyroid; Toxic Multinodular Goiter; Radioactive Iodine-Induced Hypothyroidism
• Intervention / Treatment: Radiation: radioacive iodine therapy

• Study Type: Observational
• Enrollment (Anticipated): 150

Contacts and Locations

Study Locations

• Belgium
  • Brussels, Belgium, 1090
    • Universitair Ziekenhuis Brussel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Hyperthyroid patients, either subclinical or overt, who have undergone RAI treatment in the time period of 2005-2015. They have underlying toxic multinodular goiter or a toxic nodule.

Description

Inclusion Criteria:

• Hyperthyroid patients, either subclinical or overt, who have undergone RAI treatment in the period of 2005-2015.

Exclusion Criteria:

• Prior use of L-thyroxine
• Prior thyroid surgery
• Prior RAI treatment
• Patients with thyroiditis

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Toxic Nodule; Hyperthyroid patients with underlying toxic nodule	Radiation: radioacive iodine therapy; Hyperthyroid patients who have undergone radioactive iodine treatment to cure them from their hyperthyroidism.
Toxic multinodular goiter; Hyperthyroid patients with underlying toxic multinodular goiter	Radiation: radioacive iodine therapy; Hyperthyroid patients who have undergone radioactive iodine treatment to cure them from their hyperthyroidism.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The proportion of patients in which hypothyroidism occurs	The proportion of patients in which hypothyroidism occurs after radioiodine treatment	Within 1 year after treatment
The proportion of patients in which hypothyroidism occurs	The proportion of patients in which hypothyroidism occurs after radioiodine treatment	Between 1-2 years after treatment
The proportion of patients in which hypothyroidism occurs	The proportion of patients in which hypothyroidism occurs after radioiodine treatment	Between 2-5 years after treatment

Collaborators and Investigators

• Sponsor: Universitair Ziekenhuis Brussel
• Investigators: Principal Investigator: Corina Andreescu, Doctorate, Universitair Ziekenhuis Brussel

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 11, 2020
• Primary Completion (ACTUAL): November 24, 2020
• Study Completion (ANTICIPATED): May 1, 2021

Study Registration Dates

• First Submitted: November 26, 2020
• First Submitted That Met QC Criteria: December 4, 2020
• First Posted (ACTUAL): December 11, 2020

Study Record Updates

• Last Update Posted (ACTUAL): April 19, 2021
• Last Update Submitted That Met QC Criteria: April 14, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Thyroid Diseases; Hypothyroidism; Hyperthyroidism
• Other Study ID Numbers: 2019/435

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The data may be shared with other researchers to continue this type of research in this particular domain and to answer further questions that arise from the process of this study.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No