The purpose of this study to learn more about the use of redifferentiating medications as a standard treatment for radioactive iodine/RAI-refractory thyroid cancer. This study is a registry study.
Patients ≥ 18 years old at time of consent
Patients diagnosed with RAI refractory thyroid cancer or unlikely to respond to RAI.
Patients who will receive redifferentiation agents prior to planned diagnostic and/or therapeutic use of radioactive iodine as part of routine clinical care.
Patients who have never received redifferentiation agents outside of a clinical trial or have received redifferentiation agents in the context of a clinical trial will be enrolled after the clinical team has decided to proceed with a redifferentiation agent as part of routine clinical care prior to diagnostic and/or therapeutic radioactive iodine administration.
RAI refractory thyroid cancer patients that will receive redifferentiation agents prior to diagnostic and/or therapeutic use of radioactive iodine as part of a prospective clinical trial.