CT scan radiation can equal nuclear bomb exposure
12:03 11 May 2007
NewScientist.com news service
Roxanne Khamsi
ACR task force report on radiation dose in medicine
Overzealous doctors who order unnecessary body scans that use X-ray technology are placing their patients at risk of cancer, radiologists warn.
Radiation from such scans is in some cases equivalent to that received by some survivors of the Hiroshima and Nagasaki atomic bombs, they say. In response, hospitals and professional associations, such as the American College of Radiologists, are taking new steps to promote more careful use of scanning technologies.
Radiologists are particularly concerned about the use of computed tomography, also known as CT or CAT scans. This technology involves the use of an X-ray generating device that rotates around the patient's body. These powerful beams are picked up by an array of detectors and used by a computer to generate a three-dimensional view of a body region.
Experts agree that when used correctly, such scans can save lives. However, according to some estimates, the radiation exposure a patient receives from a full-body CT scan is often 500 times that of a conventional X-ray and about the same as that received by people living 2.4 kilometres away from the centres of the World War II atomic blasts in Japan.
A CT scan might increase a person's risk of cancer by about 0.05%, although experts stress that on average a person's lifetime risk of cancer is about 20%.
Unnecessary scans
Radiologist Steven Birnbaum, who works in Nashua, New Hampshire, US, says he became acutely aware of the problem after his 23-year-old daughter suffered a head injury, including severe concussion and skull fracture.
Over the ensuing week, Birnbaum's daughter received a total of nine scans – including multiple scans to assess the bladder – until he ordered doctors to stop. Some of the scans she received were medically unnecessary, he says.
"I was horrified. I asked the surgical chief resident if any thought had been given to radiation exposure in patients when doctors ordered CT studies," says Birnbaum, who is a paid consultant for Anthem Blue Cross and Blue Shield, a major healthcare provider.
Short cuts
Magellan Health's National Imaging Associates, a leading US company that helps hospitals and healthcare providers manage their use of medical screening technologies, has initiated a new system to flag up patients that have received too many scans.
Radiologist Thomas Dehn, the company's chief medical officer, says that there are numerous reasons why CT scans are ordered unnecessarily. Doctors are often pressed for time and use the technology as a shortcut, he says. And patients sometimes demand the extra reassurance that a scan can give – a scan can help confirm they are healthy.
A task force within the American College of Radiologists (ACR) published a report earlier in May outlining ways to address the problem of excessive CT scanning.
One recommendation in the report suggests that medical students should receive mandatory training on this issue. It also says that the risks of these scans need to be better conveyed to the public. "We're concerned and we're aware of it," says Arl Van Moore, chair of the ACR.
http://www.newscientist.com/channel/health/cancer/dn11827-ct-scan-radiation-can-equal-nuclear-bomb-exposure-.htmlCT Scan Radiation Risk Even Concerns Conservative FDA Officials
Regulators at the Food and Drug Administration (FDA) are concerned that the growing popularity of high-tech computerized body imaging for health screening could be exposing the public to risky levels of radiation.
Recent advances in computerized tomography (CT) technology have increased the efficiency and lowered the price of the scans. The changes have helped spawn a new nationwide industry of unregulated boutique clinics where patients pay $300 to $500 of their own money to get CT scans not for diagnosis, but for regular health screening.
The agency is worried that easily available screening with CT has the potential of exposing patients to unhealthy repeat doses of the X-ray radiation the machines use to form images. While FDA evaluates the safety and effectiveness of CT scanners and other medical devices for regular use, it has no power to regulate how those machines are used once they reach doctors offices.
Whole-body scans require higher doses of the X-ray radiation CT scanners use to make images. As more and more people visit clinics to be screened for lung cancer, heart disease and other ailments, they could be absorbing more radiation more often than the FDA originally intended.
It's an open free-for-all in many communities. There is a perception by the public that CT scanning is a benign thing.
The average whole-body CT scan delivers 0.2 to 2.0 rads of radiation, depending on the size of the patient's body. Studies of Japanese survivors of the US atomic attacks on Hiroshima and Nagasaki in WWII linked an increased risk of cancer to lifetime cumulative exposures of 5 to 20 rads.
At 2 rads per exam, we're not far from potentially dangerous radiation doses.
Most doctors who work with CT scanners know to monitor the cumulative radiation doses patients receive. Professional societies also put out guidelines designed to promote the safe and effective use of the machines. But the self-pay nature of many CT boutiques allows patients to visit several different clinics as often as they like.
http://www.mercola.com/2001/may/30/ct_scan.htm--------------------------------------------------------------------------------
Dr. Mercola's Comment:
Folks, this is a no-brainer. X-rays are not your friend.
Does this mean you should NEVER have them. Absolutely not.
However, they need to be used with extreme caution. if at all, especially if the patient is a young child as they are particularly susceptible to the damage of radiation.
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
