The Incidence and Risk Factors of Radiotherapy Induced Hypothyroidism in Head and Neck Cancer With Long Term Follow up

The Incidence and Risk Factors of Radiotherapy Induced Hypothyroidism in Head and Neck Cancer

This is a retrospective study with long term follow up to evaluate the incidence, timing and risk factors of radiotherapy induced hypothyroidism in non-thyroid head and neck cancer patients who were treated with RT alone or in combination with surgery and/or chemotherapy.

Study Overview

• Status: Completed
• Conditions: Head and Neck Cancer
• Intervention / Treatment: Diagnostic test: TSH, T3, T4 and thyroid gland DVH

Detailed Description

For any patient, fixation was done by a thermoplastic mask. CT scan was done at 3mm thickness for the head and neck region. CT images were transferred to the planning system. Three-dimensional conformal RT, intensity-modulated radiotherapy (IMRT) or Volumetric modulated arc therapy (VMAT) was created. All patients were irradiated with once-daily fractionation at 1.8-2.0 Gy/d with 6-MV photon beams for five days a week. The gross target volume (GTV) was treated with a dose of 70Gy and the lymphatic site (CTV) and areas of high risk microscopic disease (CTV) including lymph nose levels received a radiation dose ranging from 54-66 Gy according to its risk. PTV is a circumferential margin of 5mm around CTV.

Thyroid function parameters:

The patient's serum T4, T3 and TSH levels, were measured during follow up. Clinical hypothyroidism is defined as the increase in TSH above 5.0mIu/ml with a decrease in free thyroxine levels (free T4) in the serum while elevated TSH with normal free T4 levels was labeled as subclinical hypothyroidism .As per institutional values, the normal values intervals of T4 level (7- 25 PMOL/L), T3( 1.5-7 PMOL/L),TSH (0.2-5 mIu/L).

The median time to onset of hypothyroidism was defined as the time interval between completion of radiotherapy and first abnormal recorded T3/T4/TSH value.

For all treated patients, thyroid gland was delineated and by reviewing the DVH, the V45, V50, V55, V60, V65 and V70 which means the volume of the thyroid gland receiving 45 Gy, 50 Gy, 55Gy, 60 Gy and 70 Gy respectively.

• Study Type: Interventional
• Enrollment (Actual): 101
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt, 11311
    • Department of clinical oncology and nuclear medicine, Cairo university

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Non-thyroid head and neck cancer patients who were treated with RT alone or in combination with surgery and/or chemotherapy

Exclusion Criteria:

• Patients with thyroid gland disease or abnormal thyroid hormone levels before radiotherapy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The the incidence of hypothyroidism	Measuring the thyroid function tests	8 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The risk factors of hypothyroidism	Defining the risk factors of hypothyroidism	8 months

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2017
• Primary Completion (Actual): June 1, 2018
• Study Completion (Actual): June 5, 2018

Study Registration Dates

• First Submitted: October 2, 2018
• First Submitted That Met QC Criteria: October 5, 2018
• First Posted (Actual): October 9, 2018

Study Record Updates

• Last Update Posted (Actual): October 9, 2018
• Last Update Submitted That Met QC Criteria: October 5, 2018
• Last Verified: October 1, 2018

More Information

Terms related to this study

• Keywords: radiotherapy; head and neck cancer; hypothyroidism
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Site; Endocrine System Diseases; Thyroid Diseases; Head and Neck Neoplasms; Hypothyroidism
• Other Study ID Numbers: H&N82017

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

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