Method of Endogenous TSH Stimulation in the Follow-up of Differentiated Thyroid Cancer

Not Applicable

Completed

• Conditions: Thyroid Cancer
• Interventions: Drug: L-thyroxin

• Registration Number: NCT01840332
• Lead Sponsor: University of Tartu

Brief Summary

The treatment of differentiated thyroid cancer (DCT) includes surgery followed by radioiodine treatment. In the follow-up of patients it is necessary to induce TSH elevation to test for cancer recurrence. One of the options is to stop L-thyroxin replacement for several weeks. Current pilot study aims to induce the necessary TSH elevation by decreasing the L-thyroxin dose. The main hypothesis is that necessary TSH stimulation will be achieved during 4-6 weeks in majority of patients.

Detailed Description

The treatment of differentiated thyroid cancer (DCT) includes surgery followed by radioiodine treatment. In the follow-up of patients it is necessary to induce TSH elevation for the measurement of thyreoglobulin and/or total body scanning. There are two principal methods to obtain TSH elevation: 1) injection of recombinant human TSH , and 2) to stop L-thyroxin replacement for several (3-4) weeks. As use of recombinant TSH is rather expensive, this method is not feasible in many countries. The problem with stopping L-thyroxin is development of severe hypothyroidism for several weeks with concomitant symptoms and signs.

Current pilot study aims to induce the necessary TSH elevation by decreasing the L-thyroxin dose. The main hypothesis is that necessary TSH stimulation will be achieved during 4-6 weeks in majority of patients with fixed dose of L-thyroxin. Concomitantly, blood tests and symptoms and signs of hypothyroidism will be obtained to get information about possible deviations during treatment with low dose of thyroxin.

Study Timeline

• Study Start: 2013-04
• Study First Submitted: 2013-04-22
• Study First Submitted QC: 2013-04-22
• Study First Posted: 2013-04-25
• Primary Completion: 2014-02
• Study Completion: 2014-02
• Status Verified: 2014-03
• Last Update Submitted: 2014-03-13
• Last Update Posted: 2014-03-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Differentiated thyroid cancer
• treated by thyroidectomy and at least 1 ablation with 131-I > 5 months ago
• TSH < 4 imU/L

Exclusion Criteria

• Pregnancy
• Known metastasis

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
L-thyroxin	L-thyroxin	this is one arm study

Primary Outcome Measures

Name	Time	Method
TSH level at the end of study	4-6 weeks	The percentage of patients obtaining TSH level at least 30 imU/L at the end of study period.; Blood tests will be obtained after 4 weeks. If TSH \> 30 the patient has completed the study. If TSH \< 30 patient will continue for 1 week and blood tests will be obtained after week 5. If TSH \> 30 the patient has completed the study. If TSH \< 30 patient will be monitored during 1 week and blood tests will be obtained after 6 weeks.

Secondary Outcome Measures

Name	Time	Method
change in Billewitz index during the study	4-6 weeks	Billewitz index measures the severity of hypothyroidism symptoms. Billewitz index will be recorded after 4 weeks and after 5 and 6 weeks if patient continues after 4 or 5 weeks (see primary endpoint for details).

Trial Locations

Locations (2)

East Tallinn Central Hospital; 🇪🇪 Tallinn, Estonia

Tartu University Hospital; 🇪🇪 Tartu, Estonia