3 weeks Ago By Sophie Buchan
There is growing concern about the risk of cancer which could be associated with CT scans, researchers have warned . It comes as a new study, published in the journal JAMA Internal Medicine , suggests radiation from CT (computed tomography) scans in the U.S.
may cause up to 100,000 new cancer cases a year, and nearly 10,000 of them are in children. The reason for this could be because "CT scans increase the risk of cancer due to the use of ionising radiation. The risk to individuals is low and benefits most often outweigh the risks, as long as the scan is clinically justified.
" In fact, its findings "suggest that if current radiation dosing and utilization practices continue, CT-associated cancers could eventually account for 5% of all new cancer diagnoses annually." Since 2009, the number of CT scans carried out in the US has risen by 30 per cent and now, researchers from The Institute of Cancer Research, London, Kaiser Permanente Washington, Seattle, and the University of California, San Francisco, are concerned about the increase in radiation doses used in CT scans and the rising rates of use in the US. The research team concluded the "number of cancers expected in future in the US population that will be linked to the 93 million CT scans carried out on 62 million people in 2023.
" The researchers further discovered the CT scans carried out in 2.5 million children would result in 9,700 cancers. However sensitivity to radiation differs by age, with certain organs being more vulnerable at different life stages.
For example, in adults, future cancer risks are more commonly associated with CT scans of the chest and abdomen, while in children, brain CTs pose a greater risk. These scans play a vital role in diagnosing cancer, identifying bone injuries, and guiding medical treatments. Researchers further highlight when scans are clinically warranted, the benefits to the patient typically outweigh the risks.
This is especially true if the radiation dose is tailored to the individual’s age and the specific organ being examined. Talking about the findings, Professor Amy Berrington , Leader of the Clinical Cancer Epidemiology Group at The Institute of Cancer Research, London, who co-led the study, said: “While CT scans are immensely beneficial in diagnosing and detecting many conditions, including cancer, they do involve exposure to ionising radiation that has been shown to increase the risk of developing cancer. "It’s important to note that for the individual patient, this increased risk is small, and the benefits far outweigh the risks if the scan is clinically justified.
"But when millions of CT scans are being carried out across the population, these small risks do add up. In the US, CT-related cancers could now account for 5 per cent of all cancers – some of these cancers could be prevented by avoiding unnecessary scans and ensuring correct doses are used. “While the NHS in the UK has a much better system to ensure that CT scans are clinically justified, we must not get complacent.
Many other countries in Europe and also Australia perform high numbers of scans – and these numbers are rising. We are urging doctors to ensure that scans are only carried out where necessary, and that doses are appropriate for the patient.” Dr Rebecca Smith-Bindman, Radiologist and Professor of Epidemiology and Biostatistics, Obstetrics, Gynecology and Reproductive Medicine at the University of California San Francisco , said: “These future cancer risks can be reduced either by reducing the number of CT scans (particularly low value scans which are used in situations where they are unlikely to help the patient) or by reducing the doses per exam.
"The doses for CT remain highly variable across patients’ hospitals, even in the UK, and there are opportunities to reduce those doses without reducing the accuracy of the tests.”.
