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Kmietowicz did not go far enough in highlighting the consumerist nature of commercial body CT scanning.1 Well, asymptomatic young and middle aged patients have a low pretest probability and wouldn’t benefit from a screening test. Furthermore, non-symptom led, non-focused investigations are rife for misinterpretation and error.2 The initial scanning centres in the United States targeted educated, affluent, health conscious neighbourhoods where there was a preoccupation with wellness and immortality and advertisers fed into these insecurities.3 This reflects the ethos of big corporations’ intent on making profits rather than promoting health. We would do well to heed the lesson from America where there has been a decline in the number of patient funded scans following dissuasion from professional societies.
Leaving aside the issue of stochastic effect of the radiation, there is the issue of administering contrast—a double edged sword in scanning terms.4 Without contrast—the most common scenario in CT screening—the merit of the study is questionable, with again a gamut of future medicolegal connotations with missed diagnoses. With contrast, nephrotoxicity remains a notable cause of renal impairment, not to mention life threatening complications such as anaphylaxis. In a normal, physician referred scan, because of the altered risk benefit balance, the use of contrast to show potential abnormalities becomes justified, indeed almost mandatory. In self referred studies, with inherent low sensitivity, the use of contrast becomes more ethically contentious.
Further evidence may be available on screening at least for lung carcinoma in the at risk population with the National Lung Screening Trial in America, which has enrolled 50 000 subjects though won’t be ready to publish its findings for a number of years. Until then, the tongue in cheek medical acronym VOMIT sums up the argument against consumer-led CT screening succinctly—victim of medical investigative technology.
Competing interests: None declared.