Call to cease CT scans of worried well
Asymptomatic individuals should not be offered full body scans, says Comare.
Private clinics should stop offering asymptomatic patients whole body CT scans. That’s the verdict of the Committee on Medical Aspects of Radiation in the Environment (Comare) which presented its report to the Department of Health in December.
Comare’s 12th report: The impact of personally initiated X-ray computed tomography scanning for the health assessment of asymptomatic individuals says there is little evidence to justify body scanning the “worried well”, and that the potential benefits of earlier diagnosis and treatment do not outweigh the potential risk of a significant radiation dose.
“The radiation exposure from a whole body CT scan is between 4 and 24 mSv (biologically effective dose). An effective dose of 10 mSv (equivalent to 500 chest radiographs – Hart and Wall, 2004) results in a risk of cancer death of 1 in 2000.”
Comare also recommends that CT scanning for spinal conditions, osteoporosis and assessing body fat should stop, and that lung scans in asymptomatic individuals offer little benefit. However, Comare accepted that CT scanning to determination coronary artery calcification and CT colonography.
The independent committee of experts also points out that false positives,and the detection of something which later proves to be harmless, puts the NHS and public resources under unnecessary pressure and can be harmful to an individual’s psychological well- being.
“The major challenge in whole body CT scanning is findings of unknown clinical significance. They refer to the identification, from a whole body CT scan, of an anatomical anomaly the clinical significance of which is unknown. The vast majority of such anomalies are of no importance to the individual but they will lead to uncertainty on behalf of both the health professionals and the individual.”
It also warns that negative scans may lead individuals to believe they are healthy, when in fact they may be at risk of a life-limiting condition that cannot be detected by a CT scan.
Dr Gill Markham, vice president of the Royal College of Radiologists who contributed to the report, said: “In the case of “whole body scanning” services, the College supports the conclusion of Comare’s report, that the potential risks outweigh the benefits. It is important to make clear that CT scanning in the context of illness is an invaluable technique, essential to the practice of modern medicine.
“The College welcomes opportunities to work with the Department of Health and the companies involved on rigorous standards of practice for these services, and the development of a regulatory framework.”
Lifescan, the UK’s largest private provider of organ-targeted screening, urged the government to look at the benefits of early diagnosis through CT screening at low doses.
As Dr John Giles, clinical director of Lifescan, points out, diagnostic imaging services have prevented the premature deaths of thousands of people, and those survivors happily testify that their money was well spent.
Should the worried well be able to access commercial diagnostic imaging services? Are companies such as Lifescan providing a valuable healthcare service or exacerbating health anxieties? Email the editor
Click here for Comare's full report.
Posted: 02/01/2008
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