TSH Goal for RAI Therapy

Introduction to TSH Elevation

A TSH level ≥30 mIU/L is required before RAI administration because this degree of TSH elevation maximizes radioactive iodine uptake by residual thyroid tissue and any microscopic cancer cells, which is essential for effective remnant ablation and treatment of differentiated thyroid cancer, as recommended by the American Society of Clinical Oncology 1, 2

For low-risk patients with no known residual disease after total thyroidectomy, 30 mCi RAI is typically administered with rhTSH stimulation, according to the American Thyroid Association 1
For intermediate-risk patients, 30-100 mCi is used with either rhTSH or withdrawal to achieve adequate TSH stimulation, as suggested by the National Comprehensive Cancer Network 1
For high-risk patients or those with residual/metastatic disease, ≥100 mCi is administered, again requiring TSH ≥30 mIU/L regardless of preparation method, as recommended by the American College of Endocrinology 1, 2