Comparison of I-124 PET/CT to I-123 Whole Body Imaging for the Diagnosis of Thyroid
Persons diagnosed with thyroid cancer are often treated initially with a thyroidectomy, which is followed by ablation using Iodine-131, a therapy which has been shown to be effective and safe. Imaging of metastatic thyroid cancer has been performed with whole body I-131 and Iodine 123 (I-123) imaging for many decades and use I-123 for staging studies. Iodine 124 (I-124) is a radioisotope of iodine which emits a positron and is imaged using PET (positron emission tomography). This is a single arm prospective trial that evaluates the ability of Iodine-124 (I-124) to detect metastatic thyroid cancer compared to non-interventional, usual care I-123 and I-131 images.
• Age \>= 18 years.
• Histopathologically confirmed differentiated thyroid cancer, with clinical concern for metastatic disease:
‣ Metastatic disease seen on I-123 SPECT, Fluorodeoxyglucose (FDG) PET, CT scan or ultrasound.
⁃ Elevated thyroglobulin in participant after total thyroidectomy.
• i. Participants with an undetectable thyroglobulin will be allowed if thyroglobulin antibodies are present.
• Meeting criteria for one of the following two populations:
‣ American Thyroid Association (ATA) intermediate or high-risk thyroid cancer and planning on treatment using I-131.
⁃ Metastatic disease on imaging (CT, MRI, ultrasound or FDG PET), and considering localized therapy such as surgery and radiation therapy.
• Undergone total thyroidectomy.
• Planned I-123 imaging within 45 days after enrollment.
• Ability to understand a written informed consent document, and the willingness to sign it.