Leukemia after a small dose of radioiodine for metastatic thyroid cancer.

Radioiodine is widely used in the treatment of thyroid cancer. It is one of the most benign forms of therapy for malignancy. Leukemia is a rare complication of 131I therapy, usually occurring after cumulative dosages of more than 800 mCi and with intervals between doses of less than 12 months. We report the occurrence of acute myelogenous leukemia in a 28-yr-old woman 14 months after receiving a total dose of 300 mCi 131I for metastatic follicular thyroid cancer. We also review the published literature of the incidence of leukemia after low dose 131I.