Ask Thry'vors Archive Categories

• Beginnings
• Pathology and Cytology
• Surgery
• Treatment and Follow-up
• Radioactive Iodine
• Low Iodine Diet
• Thyroid Hormone Replacement and TSH Level
• Psychological impact of Thyroid Cancer
• Other Related Health Issues
• Women's Issues
• Men's Issues
• Children and Youth Issues

Men's Issues

1. Can male fertility be affected by RAI treatment?

   Feig (June 1/06)

   Oligospermia (low sperm count) may occur transiently, but long-term male infertility is rare except after high doses.

   In one study of men who had received radioiodine for thyroid cancer, there was a transient elevation in serum FSH after radioiodine which normalized within 9 months from the last administration. They concluded that radioiodine treatment may result in transient impairment of gonadal function, but the risk of infertility in these patients is minimal. Patients requiring multiple administrations for persistent or metastatic thyroid cancer may be at greater risk of gonadal damage, although even in this group they found no evidence of infertility.

   In a patient who has undergone RAI therapy for thyroid cancer, is there an increased risk of genetic and chromosomal abnormalities to the children?

   No. Genetic and chromosomal abnormalities due to exposure to 131-I probably occur in only one percent of live births after a cumulative dose of 500 mCi (18500 MBq), and even less frequently after lower doses. (The average dose given to ablate the thyroid after total thyroidectomy for thyroid cancer is 100 mCi).