Early and late toxicity of radioiodine therapy: detection and management

To review the early and late toxicity associated with radioiodine (131I) therapy, highlighting the need for early detection and, where possible, preventive measures.

We performed a literature search on MEDLINE using the terms radioiodine, 131I toxicity, complications, Graves disease, and thyroid cancer and chose the most relevant studies for this review. Where appropriate, we refer to our own published series of patients as well.

Uptake of 131I into the salivary glands, lacrimal glands, fetal thyroid, and adult thyroid accounts for the early toxic effects of radioiodine therapy. Delayed radiation effects to the gonads, bone marrow, and cell nuclei give rise to late complications. Toxicity may also arise from uptake into metastatic tumors located at vulnerable sites, including the spinal cord, brain, and lungs.

Although radioiodine therapy for benign and malignant thyroid disorders is usually well tolerated, clinicians involved in the management of thyroid disorders need to be aware of the potential toxicity of radioiodine and take all measures to reduce these effects to a minimum.