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Thursday, January 29, 2004Radiation from X-rays in dentist surgeries and hospitals causes 700 people in Britain to develop cancer each year, researchers say today. Although medical X-rays help diagnose disease, they have long been known to cause a small increase in the risk of cancer because of the radiation they emit. ...Researchers from Oxford University and Cancer Research UK estimated the size of the risk based on the number of X-rays carried out in Britain and in 14 other countries. According to their findings, published in the medical journal The Lancet, the results showed that X-rays accounted for six out of every 1,000 cases of cancer up to the age of 75, equivalent to 700 out of the 124,000 cases of cancer diagnosed each year. From the second link: Around 700 cancer cases a year are caused by X-ray examinations, a study shows. But that works out at just 0.6 per cent of the 124,000 patients a year who are diagnosed with the disease. ....Dr Amy Berrington de Gonzalez, who led the study, said: ''The possibility we have over-estimated risks cannot be ruled out, but it seems unlikely we have underestimated them substantially." Amazing how the same numbers can be used so differently. UPDATE: A reader with radiology experience writes: Your small blurb about the effects of medical radiation struck a chord as a radiologist. Statisitically, when you attempt to predict at the low end of the dose effect curve as these people do, you become very unpredictable and inaccurate, however, there is no question that when the studies are reviewed, that even low dose radiation is carcinogenic and will be responsible for causing some cases of cancer in the population at large. How many, is really another question, as I said. That said, every physician who orders or interprets xrays needs to be mindful of these effects when they use them, especially as our need and use of medical diagnostic or therapeutic radiation is increasing dramatically. Many of our present diagnostic studies, particularly, the most used, diagnostic CT, is not as low dose as people may think. We are obtaining more and thinner cuts, dramatically increasing the amount of information we can obtain and the tasks we can perform with this modality, but at a tremendous radiation expense. It has been quoted, how accurate I don't know, that as much as 70% of the medical radiation dose to the American population is from diagnostic CT! When, for example, you see the dramatic increase in number in the use of say Chest CT's for the exclusion of pulmonary embolism, this is believable and quite frankly staggering. Our typical patient for this study from the ER, is an under 50 woman, with vague respiratory symptoms. This study has become so easy to order and fast to do, that no corroborating studies are obtained prior to getting the study. No blood gases, no d-dimers, no chest xrays. We have patients returning to the ER frequently, who get these studies, all negative, sometimes as frequently as 6 times in 6 weeks. This would also apply to the use of abdominal CT. This is distressing. When you directly see the tremendous overuse of this modality, you start to realize, that applied to the population as a whole, this is going to have a price to pay and radiation induced malignancy is it. Hmmm. We do use CT scans of the chest a lot, and the abdomen, too. And then, when the radiologist sees something that's not quite normal, but not quite abnormal, either, he usually recommends a follow-up CT scan in a few months. And then, they see something else in the follow-up CT scan and recommend yet another. I have a couple of patients who are on their third or fourth follow-up CT for uncertain findings that, truth be told, are done more for our own protection than theirs. Yet another way our litigation culture is influencing healthcare - and health. posted by Sydney on 1/29/2004 09:53:00 PM 0 comments 0 Comments: |
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