Answer to Question #12778 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
I have had many computed tomography (CT) scans throughout my adult life. How concerned should I be and how should I best assess my cancer risks? I never asked for the CT scans. What criteria should I use for determining when I need tests that use radiation? I cannot expect the doctors to always make the best choices for my clinical situation.
The answer to your questions are given below:
How concerned should I be and how should I best assess my cancer risks?
Answer: While you have received many more CT and other exams using radiation than most people your age, the possible increase in your future risk of developing cancer from these exposures is still fairly low (on the order of about 3%). This number is likely an upper limit on the risk and, in fact, the risk might be much lower or even zero as we are not certain about the risk of radiation at the low doses associated with most diagnostic imaging examinations. This compares to a lifetime average risk of developing cancer of approximately 38% based on the most recent (2013–2015) NIH Surveillance, Epidemiology, and End Results (SEER) data.
What criteria should I use for determining when I need tests that use radiation? I cannot expect the doctors to make the best choices for my clinical situation.
Answer: While I certainly understand your concern, you should expect your doctor to make the best choice of diagnostic tests for your clinical situation. That is one of the important things they are trained to do. If they are uncertain regarding the use of a diagnostic imaging examination, they can consult with the attending radiologist to confirm that the exam they ordered is the best for the clinical question at hand. If you feel that may not have been done, you are well within your right to ask to speak with the radiologist directly or another physician in the practice to reassure yourself that the care you are receiving is appropriate for your current condition. There is no doubt that some exams are ordered unnecessarily. However, in recent years there has been a concerted effort to educate all stakeholders about the need to use best practice when both deciding on the use and deciding on the manner of performing diagnostic imaging exams utilizing ionizing radiation. See the Image Gently website for further details.
Jerrold Bushberg PhD, DABMP, DABSNM, FHPS, FAAPM
Clinical Professor, Radiology
Clinical Professor, Radiation Oncology