radioiodine-refractory
Thyroid cancer that no longer concentrates radioactive iodine or progresses despite adequate radioiodine therapy.
Full Definition
Radioiodine-refractory thyroid cancer describes differentiated thyroid carcinomas that have lost the ability to concentrate radioactive iodine or continue to progress despite adequate radioiodine treatment. This condition represents dedifferentiation of tumor cells with loss of thyroidal function including sodium-iodide symporter expression. Diagnosis requires demonstration of absent or insufficient iodine uptake on post-therapy scans, or progressive disease on imaging despite therapeutic radioiodine administration. Management shifts from radioiodine therapy to alternative approaches including tyrosine kinase inhibitors, external beam radiation, or clinical trial participation. This transformation significantly impacts prognosis and treatment strategies.
Usage
Usage note: Specify criteria used to define refractory status.
In Context
- "The patient's radioiodine-refractory thyroid cancer required transition to targeted molecular therapy." — Treatment planning
- "Post-therapy scan confirmed radioiodine-refractory disease with no uptake in known metastatic sites." — Nuclear medicine report