Radioactive iodine 131 is a beta- and gamma- emitter whose main therapeutic effect comes from the beta radiation.
Radioactive iodine is process similar to iodine, being transported into the thyroid follicular cells by an iodine symporter.
Radioiodine beta emissions result in tissue necrosis and ablates functional thyroid tissue over a 6 to 18 weeks or more.
The gamma component is used to scan the body to detect areas of tumor uptake for differentiated thyroid cancers.
Commonly used to treat hyperthyroidism.
Compared to control population patients treated with RAI have an elevated incidence of cancer after 10 years of follow-up.
Cancer incidence of stomach, kidney and breast cancers are increased in patients treated with RAI.
Normal and malignant differentiated thyroid cancer cells possses a sodium iodide mechanism that allows concentration of beta-admitting radiolabeled iodine.
The symporter mechanism is found within malignant thyroid tissue and iodine depletion and thyroid-stimulating hormone elevation were used to achieve sufficient uptake of iodine for her effective therapy.
Has no activity in undifferentiated thyroid cancer.
Can prolonged disease-free and overall survival in patients with metastatic disease.
In a randomized controlled, non-inferiority trial of radioiodine in patients with low risk thyroid cancer versus no radio iodine therapy: after three years of follow-up there was no clinically meaningful differences in any in points between the two groups, with approximately 4% of patients in each group having disease related events (Leboulleaux S).