Thyroid ophthalmopathy, also known as thyroid eye disease or Graves' ophthalmopathy, is a condition characterized by inflammation and swelling of the tissues around the eyes, often accompanied by protrusion of the eyeballs. This condition can lead to significant discomfort, visual disturbances, and in severe cases, permanent vision loss.

Primary treatment modalities are intravenous methylprednisolone (IVMP) and other medications for patients with moderate to severe and active thyroid eye disease. In addition, external beam radiation therapy (ERT) is an another treatment option in combination with IVMP.

Radiation therapy delivers targeted doses of ionizing radiation to the affected orbital tissues, effectively reducing inflammation. This approach is particularly beneficial for patients who may not respond adequately to steroid therapy alone or those who experience recurrent disease flares.

This study will test the efficacy of a shortened treatment regimen comprising 5 sessions of ERT to a standard protocol of 10 treatments. The primary aim is to ascertain the effectiveness of shorted radiation treatment while improving patients' quality of life.

The research methodology of this study involves comparing the standard protocol of 10 radiation treatments with a modified approach comprising 5 treatments of daily External Beam Radiation Therapy (ERT).

The primary objective of this investigation is to assess whether reducing the number of radiation treatments while maintaining the effectiveness of the therapy can lead to improvements in the quality of life for patients with thyroid ophthalmopathy.

By comparing these two treatment regimens, researchers aim to evaluate the efficacy and safety of the abbreviated radiation schedule in managing the symptoms and progression of the disease.

Participants enrolled in the study will be randomized into two groups: one receiving the standard 10 treatments and the other receiving the modified 5-treatment regimen of daily ERT. Throughout the study period, participants will undergo comprehensive assessments to monitor changes in symptoms, vision, and quality of life. These evaluations will include ophthalmic examinations, imaging studies, and patient-reported outcome measures to capture both objective and subjective measures of treatment response.

Inclusion Criteria:

• Patient with active moderate to severe thyroid eye disease with a CAS > 4 with/ without diplopia before starting IVMP
• Patient with poor response to 3 doses of IVMP (CAS drop < 1) หรือ CAS score > 3 after 3 doses of IVMP
• Patients with diplopia after 3 doses of IVMP
• Patients with Graves' Ophthalmopathy who have maintained euthyroidism
• Non-pregnant adults (aged 35 years or older)

Exclusion Criteria:

• Individuals with severe hypertension or diabetic retinopathy

Individual Participant Data (IPD) may include sensitive information about participants, such as medical history or demographic details, particularly regarding their quality of life. Sharing IPD will be conducted in accordance with Siriraj Institutional Review Board (IRB) regulations for personal data protection."

April 15 2024- April 15 2028

• Require researchers to demonstrate that their request for access to IPD has received ethical approval from Siriraj institution's Institutional Review Board (IRB).
• Require researchers to provide a clear and specific purpose for requesting access to IPD, such as conducting further analysis, validation studies, or meta-analyses related to the research findings.
• Require researchers to sign a data use agreement outlining the terms and conditions for accessing and using the IPD, including confidentiality, data security, and compliance with relevant regulations.
• Request information about the researchers' plans for disseminating the findings obtained from the IPD, including intentions to publish or present the results in scientific journals, conferences, or other venues.
• Consider requests from researchers interested in collaborating on future research projects or initiatives related to the research topic or dataset.

In this study, both participants and researchers are aware of the treatment administered due to the necessity for close monitoring of treatment outcomes and side effects by radiation oncologists and ophthalmologists.