Learn About Full-Body Screenings

In the not-too-distant past, we visited our primary care doctor when we had symptoms of illness. The doctor listened to our heartbeat, took our blood pressure, and gave an educated guess as to the diagnosis.

That was then. Now, in an age of advancing technology, the tools available to detect abnormalities in our bodies have increased exponentially. One such tool is the whole-body scan�a way of virtually slicing, dicing, and revealing our innermost workings.

Thanks to technology, today's doctors can look inside the body to search for early warnings of cancer, cardiac disease, and other abnormalities. Clinics and medical imaging facilities are touting this new service for health-conscious people. One popular scanning technique is the whole-body CT (computed tomography) screening, which typically involves scanning the body from the chin to below the hips with a form of X-ray imaging that produces cross-sectional images.

Taking preventive action, finding unsuspected disease, and uncovering problems while they are treatable: These all sound like great ideas, almost too good to be true. In fact, they may be just that.

Some caution against scans

The U.S. Food and Drug Administration (FDA) reports that it "knows of no scientific evidence demonstrating that whole-body scanning of individuals without symptoms provides more benefit than harm to people being screened." The FDA is responsible for assuring the safety and effectiveness of such medical devices, and prohibits manufacturers from promoting their use for whole-body screening of people without symptoms. The FDA, however, does not regulate practitioners, and doctors may choose to use a device for any use they consider appropriate.

But suppose an individual has a family history of diseases such as congestive heart failure or lung cancer. If such an individual chooses to undergo whole-body screening, should he or she be labeled a hypochondriac, or simply proactive?

Many Americans believe that whole-body screening is just one more tool in the pre-emptive health-care tool kit. The popularity of such screenings is demonstrated by the burgeoning number of for-profit imaging centers offering not only CT scans, but technologies like Doppler ultrasound and Electron Beam Tomography (EBT) as well. Each of these techniques produces images of the body.

The FDA recognizes CT scans as a valuable medical tool for the diagnosis of disease, trauma, or abnormality in patients with signs or symptoms of disease. Yet the FDA and many state health agencies do not recommend them for healthy people without symptoms. The FDA contends that full-body scanning of asymptomatic people has the potential to cause more problems than the tests detect, in part because they expose the individual to radiation. The agency further says that the scans can give false leads that prompt further unnecessary testing�sometimes invasive testing�and to further radiation exposure.

"When benefits outweigh the risk," says Dr. Helen Barr, director of the FDA's division of mammography quality and radiation programs, "radiation can be a good thing. But any unnecessary radiation should be avoided. Radiation can alter cells and cause cancer in the future." And critics of elective scans�which cost hundreds of dollars and typically are not covered by insurance�say the procedures prey on hypochondriacs because individuals do not need to have symptoms to get the scans.

Some say scans are smart move

On the other side of the coin, Dr. Mark Kahn, a board-certified radiologist and medical director of EBT Heart & Body Imaging, Southfield, Mich., says radiation exposure from his EBT scanner "is so infinitesimally small, the upside of information you get outweighs the small chance of radiation risk. Instead of treating disease, we're trying to find it before it becomes a problem."

Kahn says his screenings have detected early stages of kidney cancer and vascular disease. When that happens, the patient is told to take the findings back to the primary care physician and work out a treatment plan. Kahn contends that his screenings are the reason some of his patients are still alive.

CT scans, on the other hand, result in relatively high radiation exposure. Although the risks associated with such exposure are greatly outweighed by the benefits of diagnostic and therapeutic CT scans, whole-body CT screening of asymptomatic people produces questionable benefits. The FDA suggests that consumers ask themselves these questions before undergoing a CT scan:

Can it differentiate between healthy people and those who have a hidden disease? Do suspicious findings lead to additional invasive testing or treatments that produce additional risk with little benefit?

In a related scanning procedure, an ultrasound screening during pregnancy may raise a small question about the fetus. The prospective parents may be unnecessarily concerned about the anomaly and undergo numerous additional tests, costing both money and psychological anguish, only to find that their baby is quite healthy at birth. In fact, a noted research study on the efficacy of ultrasound screenings demonstrated that the screenings made virtually no difference in the outcome among women without symptoms (see the Radius Study Group feature).

The American Lung Association does not recommend routine screening because it has not been proven that early detection affects the mortality rate. Critics also fear that false positive results could lead to unnecessary and possibly harmful follow-up procedures. Mark Beamsley, a University of Wisconsin Health System family practice physician, observes that "lung cancer screenings have not been shown to be an effective tool in increasing the survival rate for this terrible disease." And the cost considerations are significant: A CT scan for lung cancer costs $350 and normally is not covered by insurance.

The FDA offers these points to consider if you're thinking of having a whole-body screening:

CT screening has not been demonstrated to meet generally accepted criteria for an effective screening procedure.

The FDA's recommendation? Before having a CT screening procedure, carefully investigate and consider the potential risks and benefits and discuss them with your physician.

Published March 24, 2008