Stop whole body scans says committee on radiation risk

Dec 20 2007

An advisory committee to the British government has called for private health clinics to immediately stop offering whole body scans to the "worried well", because they carry too great a radiation risk.

Comare, a committee which studies radiation risk says CT scans were contributing significantly to the radiation exposure of the population

Computed axial tomography (CAT or CT scans) use multiple X-ray images to build up a picture of deformity, damage or disease inside the body.

But experts say the benefit has to be balanced against the possible harm of the radiation dose.

People pay hundreds of pounds for private screening, which can involve a whole range of scans and tests to pick up potential problems and offer "peace of mind" to people who may not be suffering from any symptoms but who would like assurance that they have little to worry about.

Fifteen percent of exposure to radiation is thought to come from medical sources, almost half of that from CT scans.

Many doctors believe that while CT scans may be justified for patients who have symptoms and are suspected of having disease or are in a high risk group, a radiation dose that may be 50 to 500 times the equivalent of an ordinary chest X-ray is not always justified for people who appear to be well.

Professor Alex Elliott, chairman of Comare says there is concern about the increasing exposure, as in the U.S. the average exposure to medical radiation exceeded that of exposure to background radiation in the environment for the first time last year, and trends in the U.S., are often repeated in the UK.

Professor Elliott, says if current trends continue there may rise of cancers due to medical exposure.

According to the report a typical CT scan carries a 1 in 2,000 lifetime risk of developing a fatal cancer; the natural risk is one in four.

Apart from the cancer risk people may also be alarmed unnecessarily when the scan picks up something which later proves not to be a problem.

Comare says CT scanning for spinal conditions, osteoporosis and assessing body fat should all be stopped and regulation for CT scanning imposed.

Comare accepts there is a case for screening for colon cancer and heart disease but says these should only apply to people over 50.

Under 50's should not be scanned for colon cancer unless they were referred by a specialist and only people at intermediate risk of heart disease should have a CT scan - anybody at higher risk should be under the care of a specialist.

Comare says there is no proof that scanning can help an earlier diagnosis of lung cancer.

Britain's chief medical officer, Sir Liam Donaldson, says the report clearly points to an issue of significant concern and following consultations they will respond to its recommendations.

The Royal College of Physicians has welcomed the report and says even tests which carry a minor risk should not be performed on people with no symptoms before they have received specialist advice from a consultant.