Answer to Question #8372 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues — Positron Emission Tomography (PET)

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

Q

A friend who is staying with me had a PET (positron emission tomography) scan 24 hours ago. I have a two-year-old boy at home as well. I was wondering if it is dangerous for my little boy to be near her. Are the objects she touched dangerous?
 

A

No, your friend is not dangerous to your two-year-old. The PET injection of radioactive material decays rapidly and is also removed from the body in the urine. Approximately 20% of the dose was excreted in the urine while your friend was in the hospital and it has a very short half-life. That means after 12 hours, there is less than 1% of the activity left in the body and by 24 hours, there is no activity left. Also, nothing that she touched became radioactive. It does not come out of the skin.

Marcia Hartman, MS

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 12 June 2009. 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.