Answer to Question #7244 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
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 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.