Answer to Question #10680 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues — Therapeutic Nuclear Medicine

The following question was answered by an expert in the appropriate field:


I just received 4,995 MBq of 131I to treat papillary thyroid cancer. I stopped breast-feeding two weeks before my treatment. I would really like to continue breast-feeding my son. How long would I need to pump and dump my milk before I can breast-feed him again? If I pump and dump my milk for two or three months before I resume feeding my son, will that be sufficient time for my body to excrete all of the 131I from my body?


Both the Nuclear Regulatory Commission and the Society for Nuclear Medicine and Molecular Imaging advise mothers that any child who was being breast-fed should not receive any breast milk after 131I therapy. This is for the protection of the baby. Breast-feeding can be done for the next child born.

Additionally, since iodine is readily absorbed into breast milk, it is recommended that a mother cease lactation before therapy begins to avoid a radiation dose to the breasts from the administered 131I.

I am just letting you know what the recommendations are from nuclear medicine physicians and the government agency responsible for protecting public health. You should discuss this further with your doctor.

Marcia Hartman, MS

Answer posted on 12 June 2013. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.