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

Universitair Ziekenhuis Brussel

Status: Unknown

Conditions: Nodule Solitary Thyroid; Radioactive Iodine-Induced Hypothyroidism; Toxic Multinodular Goiter

Treatments: Radiation: radioacive iodine therapy

Study type: Observational

Funder types: Other

Identifiers

NCT04663451

2019/435

Details and patient eligibility

About

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.

Enrollment: 150 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

150 participants in 2 patient groups

Toxic Nodule

Description:

Hyperthyroid patients with underlying toxic nodule

Treatment:

Radiation: radioacive iodine therapy

Toxic multinodular goiter

Description:

Hyperthyroid patients with underlying toxic multinodular goiter

Treatment:

Radiation: radioacive iodine therapy