Answer to Question #7244 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:

Q

Our doctor has recommended a DMSA scan for our 16-month-old son to determine the level of scarring on a duplex kidney. I assume technetium-99m will be used for this procedure. I cannot find any listing of specific risks to a small child from this material. Can you tell me what the specific risks are to a toddler? I am trying to determine if this procedure poses more risk than it is worth.

A

A DMSA scan of the kidneys uses a radioactive tracer, technetium-99m DMSA (dimercaptosuccinic acid). This tracer is injected intravenously and is cleared from the bloodstream by the kidneys. DMSA localizes in the kidneys in order for images to be made to assess the function of the kidneys. It is prudent to avoid unnecessary exposure to radiation, especially for children. If your doctor has a clinical question about the health of your child's kidneys, the benefit of this procedure outweighs the risk to your child from this medical procedure. 

The amount of radiation dose to the kidneys from this test is not enough to cause any harm to the kidneys. The exposure to radiation from the 99mTc (technetium-99m) labeled DMSA for a toddler can be compared to the exposure to the naturally occurring background radiation he would be exposed to for a four-month period. For a typical 37 MBq pediatric dose, the radiation dose is estimated to be about 0.8 mSv.

Even though people assume that there may be a risk of cancer/leukemia from any radiation exposure, there is no human data that specifically indicates there is any demonstrated health effect from radiation dose of this magnitude.1 For warranted medical procedures with either x rays or radiopharmaceuticals, the benefit of the information obtained from the procedure significantly outweighs the risk from the radiation exposure.

Mark How, MS, Certified Nuclear Medicine Technologist
Marcia Hartman, MS, Health Physicist

1 As noted in the Health Physics Society Position Statement on "Radiation Risk in Perspective," there is no demonstrated health effect for radiation exposures below 50-100 mSv.
 

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 19 February 2008. 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.