Comparative Evaluation of 68Ga-FAPI and 68Ga-DOTATATE PET/CT and PET/MRI in Thyroid Eye Disease

NCT07835607 | Recruiting

• 1 other identifier: 2025480
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Thyroid eye disease is an autoimmune disorder that can cause inflammation and fibrosis of the extraocular muscles and orbital tissues. Accurate assessment of disease activity is important for treatment planning, but commonly used clinical scores and conventional imaging each have limitations. This prospective single-center cohort study will evaluate two molecular imaging approaches, gallium-68-labeled fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT and PET/MR and gallium-68 DOTATATE somatostatin receptor PET/CT and PET/MR, in adults with thyroid eye disease and in a control group without thyroid-related or orbital disease. The study will compare visual and quantitative imaging findings, including maximum standardized uptake value and target-to-background ratio in the extraocular muscles, and examine their associations with clinical activity score and extraocular muscle thickness. The study aims to characterize the ability of these imaging methods, separately and in combination, to assess thyroid eye disease activity.

Conditions

Thyroid Eye Disease

Keywords

FAPI; SSTR; PET; Thyroid Eye Disease

Outcome Measures

Primary Outcomes (2)

• Extraocular Muscle SUVmax on 68Ga-FAPI and 68Ga-DOTATATE PET Imaging

  Maximum standardized uptake value will be measured separately in the superior, medial, lateral, and inferior rectus muscles on PET/CT and PET/MR images for each tracer. Values will be summarized by tracer, imaging platform, eye, and participant group.

  At each imaging examination performed within the protocol-defined 1-week imaging period

• Extraocular Muscle Target-to-Background Ratio on 68Ga-FAPI and 68Ga-DOTATATE PET Imaging

  For each extraocular muscle, target-to-background ratio will be calculated as extraocular muscle SUVmax divided by background SUVmax measured using a 1-cm region of interest in occipital soft tissue. Values will be summarized by tracer, imaging platform, eye, and participant group.

  At each imaging examination performed within the protocol-defined 1-week imaging period

Secondary Outcomes (3)

• Diagnostic Accuracy for Thyroid Eye Disease Activity

  At completion of imaging and clinical activity assessment within the protocol-defined 1-week period

• Association Between PET Uptake Measures and Clinical Activity Score

  At completion of imaging and Clinical Activity Score assessment within the protocol-defined 1-week period

• Association Between PET Uptake Measures and Extraocular Muscle Thickness

  At each imaging examination performed within the protocol-defined 1-week imaging period

Other Outcomes (1)

• Visual Positivity of Extraocular Muscle Uptake

  At each imaging examination performed within the protocol-defined 1-week imaging period

Study Arms (2)

Group 1 Thyroid Eye Disease Cohort

Adults diagnosed with thyroid eye disease according to European Group on Graves' Orbitopathy criteria. Participants undergo 68Ga-FAPI and 68Ga-DOTATATE PET/CT and PET/MR imaging within one week.

Diagnostic Test: 68Ga-FAPI PET/CT and PET/MR Imaging; Diagnostic Test: 68Ga-DOTATATE PET/CT and PET/MR Imaging

Group 2 Control Cohort

Adults without a history of thyroid-related or orbital disease who undergo clinically indicated FAPI or somatostatin receptor PET imaging for another reason. Orbital PET/MR acquisition is added to the existing examination without additional radiation exposure.

Diagnostic Test: 68Ga-FAPI PET/CT and PET/MR Imaging; Diagnostic Test: 68Ga-DOTATATE PET/CT and PET/MR Imaging

Interventions

68Ga-DOTATATE PET/CT and PET/MR Imaging DIAGNOSTIC_TEST

Participants receive 3 to 5 mCi of 68Ga-DOTATATE intravenously. PET/CT and PET/MR imaging of the head and orbits is performed approximately 50 minutes after injection, with PET acquisition of approximately 5 minutes per bed position. PET/MR includes routine T1-weighted, T2-weighted, and FLAIR sequences.

Group 1 Thyroid Eye Disease Cohort; Group 2 Control Cohort

68Ga-FAPI PET/CT and PET/MR Imaging DIAGNOSTIC_TEST

Participants receive 3 to 5 mCi of 68Ga-FAPI intravenously. PET/CT and PET/MR imaging of the head and orbits is performed approximately 50 minutes after injection, with PET acquisition of approximately 5 minutes per bed position. PET/MR includes routine T1-weighted, T2-weighted, and FLAIR sequences. The exact FAPI compound should be added if specified by the radiopharmacy documentation. Required confirmation: the protocol does not identify the specific FAPI compound, such as FAPI-04.

Group 1 Thyroid Eye Disease Cohort; Group 2 Control Cohort

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Participants will be selected from adults evaluated in the Department of Nuclear Medicine at the Army Medical Center of PLA between November 2025 and December 2027. The thyroid eye disease cohort will consist of patients meeting European Group on Graves' Orbitopathy diagnostic criteria. The control cohort will consist of patients without thyroid-related or orbital disease who undergo clinically indicated FAPI or somatostatin receptor PET imaging for another reason.

You may qualify if:

• For the thyroid eye disease cohort: diagnosis of thyroid eye disease according to European Group on Graves' Orbitopathy criteria.
• For the thyroid eye disease cohort: scheduled to undergo 68Ga-FAPI PET/CT and PET/MR and 68Ga-DOTATATE PET/CT and PET/MR within one week.
• For the control cohort: clinically recommended to undergo FAPI or somatostatin receptor PET imaging for another reason, with no history of thyroid-related disease or orbital disease; orbital PET/MR is added to the existing examination without additional radiation exposure.

You may not qualify if:

• Previous bilateral orbital surgery.
• Treatment with glucocorticoids, monoclonal antibodies, or radiotherapy within the previous month.
• Inability to remain supine.
• Contraindication to MRI, including incompatible metallic implants or claustrophobia.
• Planning pregnancy, currently pregnant, or breastfeeding.

Sponsors & Collaborators

• Daping Hospital and the Research Institute of Surgery of the Third Military Medical University: lead

Study Sites (1)

Daping Hospital

Chongqing, Chongqing Municipality, 400010, China

RECRUITING

MeSH Terms

Conditions

Graves Ophthalmopathy

Condition Hierarchy (Ancestors)

Eye Diseases, Hereditary; Eye Diseases; Graves Disease; Exophthalmos; Orbital Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Goiter; Thyroid Diseases; Endocrine System Diseases; Hyperthyroidism; Autoimmune Diseases; Immune System Diseases

Central Study Contacts

Xiao Chen, PH .D

CONTACT

15922970174; xiaochen229@tmmu.edu.cn

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, Department of Nuclear Medicine

Study Record Dates

• First Submitted: September 16, 2026
• First Posted: September 23, 2026
• Study Start: November 14, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: September 23, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)