Radioactive iodine works by preferentially concentrating in thyroid tissue and emitting radiation very slowly (for up to year) to kill thyroid cells. RAI is generally very well tolerated.
Indications for RAI
The are two indications for radioactive iodine therapy
- A small dose of RAI is given
- Contraindications (RAI therapy is not appropriate): moderate to severe eye disease, suspicious thyroid nodule (s), pregnancy or desire to become pregnant in next 12 months, need for quick control of hyperthyroidism.
- Dose depends on your individual risk of recurrence and extent of your cancer
- Definite indications for RAI for cancer: tumors that have spread to the surrounding tissues, distant metastases, and when gross tumor remains at the end of surgery.
- Strong indications for RAI for cancer: large tumor size (greater than 4cm), lateral lymph node involvement, aggressive histologic subtypes.
- Definite indications to NOT give RAI for cancer: small tumors less than 1-2 cm confined to the thyroid gland with no evidence of spread to the lymph nodes or surrounding tissues.