By Sandra G. Boodman

From Beverly Hills to Baltimore, free-standing scanning centers, some located in shopping malls and many owned by radiologists, have sprung up in affluent metropolitan areas.

These centers offer a comprehensive, painless, noninvasive, head-to-pelvis examination of the body's internal organs - including the brain, heart, liver, lungs, prostate, ovaries - for a $700 to $1,300 fee that is rarely covered by insurance.

Total body scanning is based on a compelling premise: Find cancer or heart disease or a brain tumor at its earliest stage - before a patient feels any symptoms or a more conventional test can detect it - and the problem can be contained, reversed or cured.

For healthy patients the knowledge that nothing serious is wrong conveys peace of mind in the form of a "clean bill of health."

But critics - including prominent radiologists, health economists and officials at the Food and Drug Administration (FDA) - say that the practice of indiscriminately scanning healthy people is unproven, ill-advised and potentially dangerous.

CT technology, they say, is far too imprecise to be used as a mass screening tool, even though it will inevitably find a few people with cancer or serious heart disease or a brain tumor.

"These centers are playing on people's emotions, and everybody knows somebody - a friend or colleague or relative - who could have been saved if only their cancer had been discovered earlier," noted Richard Mintzer, chairman of the radiology department at Northwestern University Medical School in Chicago.

Mintzer points to his own friends: one whose kidney cancer was detected early and by accident through a scan, another who died of the same disease, discovered at an advanced stage after he had symptoms.

"People like to point to examples like that," Mintzer said, "but the reality is that we have a limited number of health care dollars."

More Harm Than Good?

Last year the American College of Radiology issued a statement saying it did not endorse such scanning.

The group expressed concern "that this procedure will lead to the discovery of numerous findings that will not ultimately affect patients' health, but will result in increased patient anxiety, unnecessary follow-up examinations and treatments and wasted expense."

"These centers are entrepreneurial ventures, and they make a ton of money," said E. Stephen Amis Jr., chairman of the radiology department at Albert Einstein College of Medicine in New York. "That's why they're growing as fast as they are," not because they are medically sound.

Thomas B. Shope Jr., special assistant to the director of the FDA's Office of Science and Health, said:

"There is no scientific evidence that whole-body scanning detects disease early or saves lives."

"What's not clear is whether these CT scans do more good than potential harm," said Shope, a physicist, who worries that radiation exposure could increase the risk of developing cancer, especially in those who undergo repeated scans.

Shope estimates that one total-body scan exposes a patient to the amount of radiation equivalent to 400 to 500 chest X-rays.

It's difficult to find a radiologist unaffiliated with a scanning center who believes whole-body tests are appropriate for people without symptoms.

"These scans are a bad idea," said Michael J. Pentecost, chairman of the radiology department at Georgetown University School of Medicine. "The idea that you have a clean bill of health is fallacious and can give patients a false sense of security.

"A person can have terrible metabolic problems that are not detected by CT scan," -- such as diabetes or hypertension, two of the leading causes of disability and death.

Another drawback, Pentecost and other critics say, is inaccuracy, in the form of false negatives - the failure to find a significant problem - and false positives - the incorrect indication of a serious problem - which inevitably triggers further testing that can be risky and expensive.

"We know from old studies of CT scans that disease is concealed - and the false negative rate is very, very high - without contrast," noted Bruce Hillman, chairman of the radiology department at the University of Virginia School of Medicine.

Contrast studies involve the injection of dye into a vein to sharpen images and aid diagnosis. Contrast is not used in whole-body scanning.

And no one knows what the false positive or false negative rate is for total-body scanning, added Hillman, who chairs the American College of Radiology's Imaging Network which analyzes screening technology, because it has never been studied, nor is it likely to be.

No Definitive Answers

CT scans, developed in the 1970s, were an enormous boon to diagnosis because they enabled doctors to visualize what was going on inside the body by providing cross-sectional images - or slices - of organs that are much more detailed than conventional X-rays.

But their ability to pick up so much - an ability that has been steadily refined over the past three decades - means that CT scans will detect a lot of incidental things that would never make a difference to patients: benign tumors, cysts, scar tissue.

CT scans cannot definitively distinguish between a growth that is benign or malignant. That requires a biopsy.

A suspicious or unexpected finding will invariably trigger a cascade of medical interventions, all of which carry their own quantifiable risks: a possible allergic reaction to the dye used in a follow-up contrast study, a potentially life-threatening lung biopsy, a painful liver biopsy and even surgery to determine whether that suspicious growth is a harmless tangle of blood vessels or a smoldering and lethal cancer.

And CT scans have limitations. Although many scanning centers say they can detect cancers at their earliest stages, CT scans cannot pick up cancers smaller than half a centimeter.

"It will certainly find some kidney tumors, but you won't find prostate cancer unless it's totally out of the box, or breast cancer or early bowel cancers," said Einstein's Amis.

Virginia's Hillman said that ovarian cancer could be detected by a CT scan "once it's big" and that emphysema wouldn't show up "unless it was pretty significant disease." A CT scan would pick up an aneurysm, which is a bulge in a blood vessel that can be life-threatening, as well as kidney stones and gallstones, he said.

As for claims that a scan can detect brain disease, Hillman said that "the likelihood of a person having brain disease without significant symptomatology is minuscule." Most brain diseases, Hillman added, are diagnosed using an MRI, or magnetic resonance imaging, device.

Sometimes, Hillman notes, CT scans find disease that is significant, even life-threatening, for which treatment rarely prolongs life. That's true of pancreatic cancer, Hillman said, and may even be true of lung cancer.

Finding cancer before a patient has symptoms may simply mean living with the devastating knowledge longer, a situation that carries its own psychological risks, doctors say.

Washington Post November 13, 2001; Page HE01