5 August 2009

Overuse of computerised tomography (CT) scans is placing patients at unnecessary risk of cancer, writes Associate Professor Graham Simpson, Director of Thoracic Medicine at Cairns Base Hospital, in the latest edition of Australian Prescriber.

Professor Simpson says there needs to be greater understanding of the indications for CT scanning of the chest.

“There is evidence that the investigation is inappropriately used, causing unnecessary expense and risking adverse events,” Professor Simpson writes.

“Since its development, CT scanning has revolutionised medical imaging, paving the way for techniques such as magnetic resonance imaging and positron emission tomography. It is, however, a relatively expensive investigation, costing almost ten times as much as a chest
x-ray.”

He also suggests health professionals underestimate the risk of malignant disease due to radiation exposure.

“In Australia CT scans probably account for 65% of the population's exposure to medical radiation. Increased radiation is associated with an increased risk of cancer, so CT scans should be used sparingly.”

Professor Simpson says it is important that CT scans are not ordered when only a chest x-ray is needed.

“Clearly, chest CT scans need to be ordered with a careful analysis of the risk-benefit ratio,” he concludes.

To read the full article, which includes guidelines for ordering thoracic CT scans, visit www.australianprescriber.com.

Australian Prescriber is an independent peer-reviewed journal providing critical commentary on therapeutic topics for health professionals, particularly doctors in general practice. It is published by National Prescribing Service Limited (NPS), an independent, non-profit organisation for Quality Use of Medicines funded by the Australian Government Department of Health and Ageing.