Answer to Question #3698 Submitted to "Ask the Experts"

My seven-year-old recently underwent an hour of flouroscopy of his colon with about 20 additional intermittent still exposures of his lower intestines. He did not have an apron. I would like to know how much exposure this would be and if we've significantly increased his risk for developing cancer and/or sterility and any other miscellaneous damage this may have caused.

It is not possible to comment with certainty and confidence regarding your son's dose and risk from his fluoroscopy procedure. A great deal of technical information as to how the study was performed would be required. We must presume that your stated hour-long fluoroscopy really meant he was on the fluoroscopy table for an hour. It is extremely unlikely that the beam was on all that time. All we can say from the information provided is that his dose was probably below the level at which radiation is known to cause adverse effects, either cancer or mutation. Your son had a serious condition, potentially life threatening. In these cases, the use of radiation, even in moderate doses, is regarded by all experts and authoritative bodies as justified. The benefit of the exposure clearly outweighed the risk—even though surgery was later required. Incidentally, the risk of the surgery was substantially greater than the risk from the radiation. Further, adverse consequences of the surgery, had they occurred, would probably have been immediate and serious. Radiation-induced cancers typically occur decades after exposure, and mutations in succeeding generations of descendants of the exposed individual.

Leaded aprons are usually used on patients to protect the gonadal region—the pelvis. Clearly, an apron in that area of your son would have blocked the view of parts of his anatomy that the radiologist needed to see. Modern technology calls for confining the x-ray beam to the part being examined. Years ago, when leaded aprons were first introduced and recommended, beams were frequently much larger. Now the function of the apron is provided at the x-ray tubehead, where the beam exits the machine.

Conclusion: Risk to your son from the fluoroscopic procedure ranged from zero to very small.

S. Julian Gibbs, DDS, PhD