What are the symptoms of Radioactive Iodine (RAI) therapy for Graves' disease?

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Last updated: March 30, 2025View editorial policy

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From the Guidelines

For patients with Graves' disease, I strongly recommend against using radioactive iodine therapy as a first-line treatment due to the potential risks of exacerbating hyperthyroidism or Graves eye disease, as highlighted in the study by 1. Instead, the treatment approach should be individualized based on the patient's specific condition and medical history. The diagnostic test used to evaluate thyroid function in patients with Graves' disease is the radioactive iodine uptake (RAIU) test. This test involves swallowing a small amount of radioactive iodine (usually I-123) and then measuring how much is absorbed by the thyroid gland after 4-6 hours and again at 24 hours. Some key points to consider when performing the RAIU test include:

  • Patients should avoid iodine-containing foods, medications, and contrast agents for 1-2 weeks before the test.
  • Patients should not eat for 4 hours before the procedure.
  • Typically, patients with Graves' disease show elevated uptake values (often >30% at 24 hours compared to normal values of 10-30%). The RAIU test helps distinguish Graves' disease from other causes of hyperthyroidism and can guide treatment decisions between antithyroid medications (methimazole or propylthiouracil), radioactive iodine therapy, or surgery, as noted in the study by 1. However, it's essential to weigh the benefits and risks of each treatment option, considering the potential for radioactive iodine therapy to cause hypothyroidism or exacerbate existing conditions, as mentioned in the study by 1. In some cases, such as patients with HCV-related extrahepatic disorders, radioiodine therapy may be effective and well-tolerated for treating Graves' disease, as suggested by the study by 1. Ultimately, the treatment approach should prioritize minimizing morbidity, mortality, and improving quality of life for patients with Graves' disease.

From the Research

Radioactive Iptakr Graves

  • Radioactive iodine (RAI) therapy is a common treatment for Graves' disease, with approximately 70% of patients in the United States receiving this treatment after initial presentation 2.
  • The goal of RAI therapy is to achieve permanent hypothyroidism, but this is not consistently achieved, with 73% of patients becoming hypothyroid, 23% remaining hyperthyroid, and 4% becoming euthyroid in one study 3.
  • Factors associated with the success of RAI therapy include smaller thyroid size and higher dose of I-131, with an optimal dose of around 250 μCi/g of thyroid tissue 3.
  • Repeated RAI therapy can be an effective option for patients who do not respond to initial treatment, with a higher remission rate after second RAI therapy compared to first RAI therapy or long-term antithyroid drug treatment 4.
  • Transient hypothyroidism can occur after RAI therapy, which can lead to delayed or inappropriate treatment if not recognized 5.
  • Treatment options for Graves' hyperthyroidism include antithyroid drug therapy, RAI therapy, and thyroid surgery, with RAI therapy being the most commonly used treatment in the United States 2, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Clinical Outcomes of Repeated Radioactive Iodine Therapy for Graves' Disease.

Endocrinology and metabolism (Seoul, Korea), 2022

Research

Treatment of Graves' hyperthyroidism: evidence-based and emerging modalities.

Endocrinology and metabolism clinics of North America, 2009

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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