Could getting a CT scan bring you more harm than good?

Dr. Nina Shapiro: An article in this week's Archives of Internal Medicine showed that getting a single CT (computed tomography) scan can tremendously increase the risk of cancer in the near and distant future. While this is a compelling article, we have to better understand how this information is being presented. This was a modeling study. The authors were likening the radiation exposure incurred by the atomic bombs of Hiroshima and Nagasaki during World War II to that received during CT scans. A significant difference is that the atomic bombs released a sudden blast of radiation in an uncontrolled fashion to the entire population, to the entire body of each person.

While CT scans do emit a higher dose of radiation than conventional X-rays, they are performed in a controlled fashion. No study has actually shown that CT scans cause cancer. The model is an extrapolation from the information gleaned from these horrific atomic blasts. But the question remains: What do we do if our doctor orders a CT scan for us or our kids?

Certainly, as with any test being ordered, or any procedure to be performed: ask questions. Is this the best test to assess the problem? Are there alternative, less "invasive" options? And as with all issues in medicine and in life, for that matter, there is always a risk-benefit analysis: which is more risky -- the swine flu or the swine flu vaccine? A Cesarean section or a VBAC? Injury from an airbag or no airbag at all? But as with all technological advances in medicine that are later fraught with concerning data, we need to all step back and realize the benefits they have brought.

CT scans have saved thousands, if not millions, of lives. They have saved people from unnecessary trips to the operating room, and, conversely, have hastened the necessity for emergency surgery. They can detect MAJOR intracranial bleeding after seemingly minor head injuries, saving countless lives, and preventing permanent brain damage. They detect tiny brain tumors, lung cancers, and abdominal cancers, which may have been otherwise missed.

While I am alarmed and concerned about the data from this article, the nature of the work warrants more studies on the safety and efficacy of this type of radiation exposure.

Dr. Nina Shapiro is a graduate of Harvard Medical School, and she completed her residency in ear, nose, and throat surgery at Harvard. She is an Associate Professor and Director of Pediatric Ear, Nose, and Throat at the Mattel Children's Hospital at UCLA. She has treated tens of thousands of children with ear problems, sleep problems, and breathing problems. She lives with her husband and two young children in Los Angeles.