Does Medical Imaging Fry Patients?
For years I've been saying that many medical procedures are far less "proven" and far more dangerous than most people think. And now we can add another one to the list -- one so commonly used, in fact, that its very commonness may be its biggest problem. I'm talking about medical imaging procedures, which doctors annually prescribe to about four million people under the age of 65. The typical patient, having received the work order, rushes over to the hospital to get the images taken, grateful for the sophisticated technology that can diagnose incipient internal problems. But according to a study just published in the New England Journal of Medicine, tests such as CT scans and nuclear imaging may be provoking cancers without providing any real benefits. (You might want to reread that last sentence again.)
The study analyzed medical records of about one million adults under 65, and found that two-thirds of them had undergone at least one imaging test between 2005 and 2007, not including "low-dose" dental X-rays. Eighty percent of the imaging procedures were performed on people who weren't in hospitals, and 30 to 40 percent were administered to patients under age 50. While 71 percent of the tests were regular X-rays, the remaining tests included high-dose CT and nuclear imaging radiation scans. CT scans emit 50 times the amount of radiation you'd get from a regular X-ray. You get even more radiation from nuclear stress tests, also known as myocardial perfusion imaging, which doctors prescribe to search for cardiovascular problems.
It may seem obvious to any non-doctor that exposing people to high levels of radiation isn't good, but study director Dr. Reza Fazel of Emory University School of Medicine seems to think that lots of physicians haven't figured that out. She says, "We don't want to scare people and have them refuse necessary procedures, but physicians and patients need to be aware that radiation is not benign. Our study shows that a lot of people are getting high doses of radiation."
And that radiation, according to experts, leads to at least two percent of new cancers in the US (about 29,000 cases a year). Keep in mind, that two percent applies only to cancers caused by CT scans, without accounting for the cancers related to nuclear imaging and other forms of medical radiation. Also, keep in mind that people don't typically receive just one scan. They may have multiple images taken at a single time or have repeat sessions of imaging, and the impact of radiation is cumulative over time.
"The risk in individual patients is small, but when you start totaling up millions of people getting these kinds of doses, it adds up, and the population risk starts to become concerning," says Dr. Fazel. It's interesting that the data show women get imaging tests at a greater clip than men -- 79 percent of women versus 58 percent of men had such tests during the study period. Not surprisingly, then, women also contract radiation-induced cancers at a greater rate.
Experts have noticed it's possible that the risks outweigh the benefits, at least in some cases. "We are exposing people to significant amounts of radiation and on the other hand we do not have evidence that [the scans lead to] improvement of health," says Dr. Michael Lauer, a cardiologist with the National Heart Lung and Blood Institute. The fact is that studies haven't been done to determine if all this scanning actually saves lives, prevents heart attacks, or leads to health improvements. (As I keep saying, medicine is not as scientific as you might think.) And experts particularly worry about exposing children to imaging, since kids are about 10 times more sensitive to radiation than adults are. Elderly people, who were not included in the study, get the most imaging done, but the reports seem to dismiss this fact. Perhaps the thinking is that they'll die soon anyway, so who cares? But at least the cost of the procedure is covered by Medicare.
In addition to the health concerns, the report cites exorbitant costs associated with imaging. According to the Radiological Association of North America, $17 billion may be paid annually in unnecessary imaging in cases of acute trauma. Doctors get paid for each service they perform, and so they may be ordering tests for which the need is questionable. The Government Accountability Office issued a report saying that Medicare spending on imaging more than doubled to $14 billion between 2000 and 2006, with most of that increase going to the highest-dose, most dangerous tests. (And we wonder why health care costs keep climbing).
Unquestionably, scanning can reveal hidden problems, and sometimes that does indeed lead to remediation and healing. Certainly, the American College of Radiology (ACR) sees the issue differently. In a rebuttal, the ACR calls the NEJM study "ill-advised and misinformed." The rebuttal claims that, "The patients who experienced the higher doses of radiation (and repeated exams) outlined in the study were almost certainly cancer patients and others with chronic illnesses whose conditions necessitated repeat exams to gauge effectiveness of their treatment and/or help ensure their short term survival." (It's useful to remember here that if those patients weren't cancer patients going into the exam, they probably were down the road as a result of the tests.) Also, the ACR refutes the claim that most imaging turns up nothing because the procedure isn't called for, saying that, "Negative exams are of value. They preclude further costly and invasive exploratory techniques, rule out disease, provide a baseline to monitor patient health, and provide the patient with peace of mind."
Really?? Perhaps they missed the studies that demonstrated that mammograms have up to a 90% false positive rate!! That means that 90% of mammograms actually lead to "further costly and invasive exploratory techniques," give false confirmation of disease, provide a totally erroneous baseline to monitor patient health, and unnecessarily destroy patient peace of mind!
While the medical community slugs it out, it might help you to know that MRI tests and ultrasounds don't use radiation, nor does thermography. Always opt for the non-radiation test where there's a choice.