Answer to Question #6670 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 am having radioactive iodine treatment to treat my hyperthyroidism. I have read all the information I can find, but my biggest question is what will happen if one of my children or my husband sits next to me or on my lap or gives me a kiss? I don't want to harm them and this scares me. I have someone to watch them for the first day of my treatment so they will not be near me for the first 36 hours or so, but I don't have any other sources. My children are 22 months, four years, nine years, and 11 yrs. Is it going to harm them to be around me or near me?

Thank you for your question. You're doing the right thing to think about possible issues and get answers. Your husband can sit next to you and your kids can sit on your lap, plus you can get a kiss and nothing bad will happen. It's all about time—how much total time is being spent right next to you or on your lap for those first few days? Based on what I know about how we treat hyperthyroidism with iodine-131, about twenty percent (one-fifth) of the radioactivity will be gone in the first 24 hours. So after 24 hours, it is much safer to be close to you. But, still, within those next few days, limiting time with your family close to you (within about three feet or so) is a prudent thing to do. After about 10-15 days, very little of the I-131 remains.

As an example, for those first few days, after the first 24 hours, someone sitting right next to you for about an hour would get the same amount of radiation dose that they ordinarily get in one day from background radiation; if they sit three feet away, they get about one-fourth of that. After about eight days, sitting close to you really adds nothing to their background radiation level, so there are few if any restrictions at that point.

Kelly Classic
Certified Medical Health Physicist

Answer posted on September 26, 2007. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of 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 specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.