This blog post will be short. It comes on the heels of three of my patients who have participated in more than one Computed Tomography (CT) scan within two years, and one of these patients had three scans within two years and two of those scans within a few months. Is this a big deal? My contention is that it is a very big deal given the amount of radiation a person receives from the scan.
Take your pick from the several legitimate websites that caution against the multiple use of CT scans in a person's history. According to Consumer Reports, CT scans expose a person to as much radiation as 200 X-Ray scans, or the equivalent to an average person's environmental exposure over seven years, from a single abdominal scan. I lived during a time when a few X-Ray scans per year was considered to elevate the risk for cancer, so why is the discussion of risk with patients so cursory and limited.
My question is: What has changed with the protocols with using CT scans that will allow a person to be exposed to two CT scans within two years? There are some people who say that the profit motive is involved, and the risk for overuse is in fact high, according to some studies. CT scanning is a multi-billion dollar business, and many specialists have vested financial interests in their use.
The overuse appears to be nationwide. In an article in the Washington Post (see citation below), a woman is described to have had four CT scans in eight years, and described its propensity for overuse when other methods with less adverse risks could be used. I fully admit that CT scans have assisted in improving diagnostic certainty, but the overuse has not been adequately investigated to address the long term consequences to the patient who has been over exposed to radiation. The patients I'm referring to have medicare/medicaid and were unfamiliar with the amount of radiation exposure from a typical CT scan, so they were unable to confidently and assertively counter the doctor's insistence in its use.
The relationship of radiation to an increase in cancer incidence is believed by the practitioners to be unproven, yet studies are finding an increase, albeit small, with such exposures. What is the patient to do? First, ask questions. Ask if there is another way to get at a diagnosis rather than use a CT scan. There is an MRI option, which has considerably less risk but more likely to come out of pocket. You can often find the same information from a sonogram, which also carries no radiation risk. Ask if there is a way to reduce the radiation exposure if a CT scan is needed. Some CT scans, such as the modern ones, have technology that varies the radiation exposure automatically as it scans. Last, ask if the results of a previous scan could be used. Here, if the scan was within three months and the issue is believed to be long standing, it may be possible. Just don't readily agree to more scans, especially if it is your child. One study in 2009 found that there in an increase in some cancers in children with repeated use.
The CT scan is useful, especially with specific physical issues, and can be a life saver. But, you will also want to be able to evaluate the cost/benefit of the exam in relation to the amount of risk. You only hope to receive adequate information to make an informed decision from the possible risks, and the option to go a different route when available.