REDWOOD CITY, Calif., July 21 (San Francisco News Online) — A brain tumor found on a preventive scan in a former “Bachelor” contestant, as reported by Fox News, has renewed attention on full-body MRI screening. For many healthy adults, though, the more important question is not whether a scan can find something, but whether it should be used in the first place.
Major medical groups say routine whole-body MRI screening is not recommended for people who do not have symptoms or a specific risk factor. The Food and Drug Administration says it knows of no scientific evidence showing that scanning people without symptoms provides more benefit than harm. The American College of Radiology says there is not enough evidence to justify total-body screening in patients with no symptoms, no risk factors and no family history pointing to serious disease. The American Academy of Family Physicians and the American College of Preventive Medicine also advise against routine whole-body scans for early tumor detection in people without symptoms.
What is a full-body MRI?
A full-body MRI is a magnetic resonance imaging scan that looks over much of the body at once. It is different from a CT scan because MRI does not use ionizing radiation. The American Cancer Society says that matters, but it does not make the scan automatically useful as a screening test. The ACS says the bigger issue is what happens after the scan: unusual spots, shadows or other findings that may turn out to be harmless.
Why are doctors cautious?
The main concern is not a missed headline-grabbing diagnosis. It is the large number of findings that may never have caused trouble. The American Cancer Society says full-body MRI can lead to false positives, incidental findings, anxiety, unnecessary follow-up tests and procedures, overdiagnosis, overtreatment and even false reassurance when the scan misses something important. The ACS says insurance companies rarely pay for these scans because they are not part of standard medical care.
That concern is shared by Bay Area researchers. UCSF radiology outcomes researcher Dr. Rebecca Smith-Bindman told CBS San Francisco that there is no evidence the scan helps people live longer or better and warned that false positives can lead to more testing. In the same local coverage, CBS San Francisco reported that Prenuvo markets full-body MRI as a way to look for more than 500 conditions, including cancer at an early stage.
Experts also warn that one abnormal image can lead to more tests that may not help. Matthew Davenport, a radiology professor at the University of Michigan, told ABC News that the harms come from invasive testing, surgery or follow-up care for findings of uncertain importance. A JAMA editorial by Davenport and Dr. Scott Reeder said no major medical group recommends whole-body MRI for the general population because the benefits have not been proven.
How much can it cost?
Cost is another reason the test is not a simple consumer choice. WebMD reported that whole-body scans can cost $2,000 or more, and the ACS says they are usually not covered by insurance. That means a healthy person may pay out of pocket for a test that major medical organizations do not recommend for routine screening.
Are there any situations where MRI screening makes sense?
The sources cited by the major medical groups draw a clear line between people with symptoms or known higher risk and people who are otherwise healthy. The concern is not with MRI as a technology. It is with using it broadly as a screening tool when evidence has not shown that it improves outcomes for the general population.
The U.S. Preventive Services Task Force has made that same kind of distinction in another cancer screening area, giving pancreatic cancer screening in asymptomatic adults who are not known to be at high risk a D rating, which means the harms outweigh the benefits.
Why does one dramatic case get so much attention?
A story about a tumor found before symptoms can make preventive scanning sound like a clear win. But the medical groups and clinicians cited in the research behind this story say one successful find does not answer the bigger question of whether widespread screening helps more people than it harms. For now, the evidence cited by the FDA, the ACR and other groups points in the other direction: full-body MRI may find abnormalities, but routine use in healthy people still has uncertain value and real downsides.
