Clinical trial NCT04663451: An Assessment of the Occurrence of Hypothyroidism in Patients Treated With RAI for Hyperthyroidism.
Official title: An Assessment of the Occurrence of Hypothyroidism in Patients Treated With RAI For Hyperthyroidism, And it's Prognostic Factors.
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Nodule Solitary Thyroid
Toxic Multinodular Goiter
Radioactive Iodine-Induced Hypothyroidism
Lead sponsor: Universitair Ziekenhuis Brussel
Sponsor class: OTHER
First posted: 2020-12-11
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
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.

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: The proportion of patients in which hypothyroidism occurs
timeFrame: Within 1 year after treatment
measure: The proportion of patients in which hypothyroidism occurs
timeFrame: Between 1-2 years after treatment
measure: The proportion of patients in which hypothyroidism occurs
timeFrame: Between 2-5 years after treatment
Secondary outcomes:
Other outcomes:
Locations:
city: Brussels
country: Belgium
facility: Universitair Ziekenhuis Brussel
Study officials:
affiliation: Universitair Ziekenhuis Brussel
name: Corina Andreescu, Doctorate
role: PRINCIPAL_INVESTIGATOR
References: