Radiation Therapy and Radioactive Iodine for the Treatment of Recurrent Papillary or Follicular Thyroid Cancer

Inclusion Criteria

• Eligible study subjects will be between the ages of 18 and 85 years, inclusive
• Eligible study subjects will have histologically confirmed papillary or follicular thyroid carcinoma, collectively referred to as differentiated thyroid carcinoma (DTC), that is incompletely responsive to initial surgery +/- 131-iodine as established by anatomic imaging (CT, magnetic resonance imaging [MRI], and ultrasound)
• Eligible study subjects will have DTC that is not completely resectable with macroscopic invasion of tumor into cervical soft tissues and/or non-resectable distant metastases
• Iodine avid residual disease, but with a sub-therapeutic level of lesional radioiodine uptake demonstrated in either a pre-treatment diagnostic scan or a previous post-treatment radioiodine scan, making it unlikely that the patient would benefit from radioiodine therapy alone
• Measured creatinine clearance > 70 ml/min/1.73 m^2 or normal radioisotope glomerular filtration rate (GFR)
• Platelet count > 50,000 cells/mm^3
• Absolute neutrophil count (ANC) > 500 cells/mm^3
• Life expectancy of at least 8 weeks
• Karnofsky performance status (KPS) > 50%
• Patients must have adequately recovered from the effects of any prior chemotherapy, as determined by the treating physician and study team, based in part on organ function defined above. Toxicities from previous therapies must have recovered to Common Terminology Criteria for Adverse Events version 5.0 (CTCAE 5.0) grade 2 or better
• Patients with previously identified cardiac disease will be eligible, as [131I] NaI is not expected to cause cardiac dysfunction
• The patient and/or the patient’s legally authorized guardian, if the patient is a minor, must acknowledge in writing that consent to become a study subject has been obtained, in accordance with institutional policies approved by the U.S. Department of Health and Human Services

Exclusion Criteria

• Patient is pregnant or breastfeeding
• Patient is sexually active, premenopausal, and does not agree to use accepted, effective forms of contraception
• Any criteria that would contraindicate radioiodine therapy or external beam radiotherapy
• Patient having American Thyroid Association (ATA) low and intermediate risk tumors, not meeting the guidelines for either radioactive iodine (RAI) treatment or external beam radiation therapy (EBRT)
• Patient with advanced central nervous system (CNS) metastatic disease, critical lesions in the hip and spine, etc that would make RAI treatment prior to EBRT potentially harmful, with respect to worsening of disease as a result of the recombinant thyroid stimulating hormone (TSH) stimulation
• Patients having recent exposure to iodinated contrast (within 6 weeks, that could render RAI treatment ineffective)