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Stanford Report, August 6, 2003

Risks vs. benefits of self-referred CT scanning weighed A growing trend in health care raises ethics concerns


Sophisticated body scanning technology has led to a proliferation of businesses enabling anyone with cash to acquire detailed images depicting their innermost anatomical workings. On the surface, this may seem like a worthwhile expense for health-minded individuals, but Stanford researchers believe the benefits of scanning remain unclear while the risks are coming into sharper focus.

In a paper published in the August issue of the journal Radiology, Judy Illes, PhD, senior research scholar in the medical school’s Center for Biomedical Ethics and the Department of Radiology, and her co-authors caution that guidelines are needed from the medical community in order to establish how and when whole-body CT scanning is appropriate. Further research is also needed to determine the fundamental usefulness of the data gleaned from such scans.

"We need guidelines today," said Illes, lead author. "Even though the scanning services are readily available and heavily marketed, we still don’t fully understand the potential risks, so fully informing patients is impossible."

The authors noted the rapid growth of direct-to-consumer scanning businesses that market their services on the Internet. Relying on Web-based search engines, they identified 88 imaging centers nationwide; Illes added that at least 48 new centers have come into being since the research was conducted last year, while one large center closed its doors due in part to market saturation.

The imaging centers are concentrated on the two coasts in areas that are largely white and affluent. The authors explained that consumers in such areas could afford the high cost of whole-body scans which range in price from $795 to $1,215 depending on factors such as whether bone density is measured or whether the head is scanned.

Proponents of self-referred whole-body CT scanning believe the risks are minor when compared with the benefits which may include early detection of disease and a sense of empowerment scans may offer. The paper’s authors, however, raise questions regarding the risk of radiation exposure associated with CT scanning, which can deliver as much as 2 rads of radiation depending on the procedure and the patient’s body — about the same as 250 chest X-rays, according to co-author Scott W. Atlas, MD, professor of radiology and a senior fellow of the Hoover Institution.

Other risks include undergoing a medical procedure that has not been evaluated for effectiveness; hidden medical and psychological consequences of false-positive results; and the risk of positive results that are clinically insignificant but lead to unnecessary medical procedures such as biopsies.

"Here you have healthy people with no risk factors turning into the ‘worried-well,’ becoming anxious about their health and perhaps undergoing expensive and invasive tests that expose them to new risks," Illes said.

Among future concerns, Illes added, is the ability to join a structural scan with a functional scan. "Parents might be concerned that their child is not doing well in the classroom, so they’ll go to an imaging center for a brain scan to try to find out why." Similarly, scanning technology could be used to screen airline passengers for security risks. A scan can show increased blood flow in parts of the brain linked to violent behavior, for example, but no one knows why that part of the brain might be more active on any given day. "There’s a great risk of misusing the technology," she said.

Given the prevalence and marketing savvy of scanning businesses, the researchers worry that the technology may become an accepted norm in the public mind before medical research establishes its effectiveness. "Currently, there are no guidelines for how these services are advertised or marketed," said Illes. She and her group are currently working on another paper that explores the industry’s marketing techniques.

Other Stanford researchers on the paper include Ellen Fan, a graduate student; Barbara Koenig, PhD, associate professor of neurology and neurological sciences and of medicine; Thomas A. Raffin, MD, the Colleen and Robert Haas Professor in Medicine and Biomedical Ethics; and Dylan Kann with the program in human biology.

Researcher’s letter raises ethics issue (3/5/03)

First-of-its-kind neuroethics event covers new turf (5/22/02)