Answer to Question #11711 Submitted to "Ask the Experts"

Category: Medical and Dental Patient Issues — Diagnostic X Ray and CT

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

Q

My wife had one computed tomography (CT) urogram; one CT of her abdomen and pelvis; one upper gastrointestinal (GI) study; one technicium-99m (99mTc) para-isopropylacetanilido-iminodiacetic acid (PIPIDA) scan of her gallbladder; and one kidney, ureter, and bladder (KUB) x ray in one year. She is 29 years old, and I'm worried about her cancer risk from these exams. Can you help me by giving me an estimate of her cancer risk?

A

The risk of additional cancer from these imaging exams is very low. Using average values found in the literature, the total effective dose from all of the exams you listed is much less than 100 millisieverts (mSv). When the total effective dose from multiple imaging procedures is less than 100 mSv, the additional risk of cancer is too low to be measured.* The increased cancer risk from these exams would be negligible.

Karen Brown, MHP, CHP, DABR

References

American Association of Physicists in Medicine. AAPM Position statement on radiation risks from medical imaging procedures. AAPM Policy PP 25-A; 13 December 2011. Available at: http://www.aapm.org/org/policies/details.asp?id=318&type=PP¤t=true. Accessed 2 October 2016.

Health Physics Society. Radiation exposure from medical exams and procedures. Health Physics Society Fact Sheet; January 2010. Available at: http://hps.org/documents/Medical_Exposures_Fact_Sheet.pdf. Accessed 2 October 2016.

Mettler FA Jr, Huda W, Yoshizumi TT, Mahesh M. Effective doses in radiology and diagnostic nuclear medicine. Radiology, 248(1):254–63; July 2008.

* Editor's note: The Health Physics Society's position statement on Radiation Risk in Perspective states, "[B]elow levels of about 100 mSv above background from all sources combined, the observed radiation effects in people are not statistically different from zero." Further, you should keep in mind that your wife received a medical benefit from these procedures. These very real benefits far outweigh any hypothetical risks from the radiation.

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 4 October 2016. 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.