Answer to Question #8924 Submitted to "Ask the Experts"
Category: Nuclear Medicine Patient Issues — Diagnostic Nuclear Medicine
The following question was answered by an expert in the appropriate field:
I am a mother and had a nuclear stress test with thallium-201 administered. What precautions should be taken with the care of my four-month-old baby and my two-and-a-half-year-old child?
The only consideration would be breast-feeding, as thallium-201 is secreted into breast milk. Assuming that you received 3 millicuries of thallium-201 for your cardiac study (a typical dose), you should hold off breast-feeding for at least two hours to keep the baby's dose below regulatory limits. If you avoid breast-feeding for longer times (24 or 48 hours), the radiation absorbed dose to your baby is lower, but the doses we are talking about are so low that it is questionable that this is a benefit.
This information comes from measurements made with the breast milk of one nursing mother and published in the article "Radiation Dose from Breastfeeding Following Administration of Thallium-201," written by R. Eugene Johnston, Suresh K. Mukherji, J. Randolph Perry, and Michael G. Stabin. This article was published in the 1996 Journal of Nuclear Medicine, volume 37, pages 2079–2082.
Carol S. Marcus, PhD, MD