REDWOOD CITY, Calif., July 21 (San Francisco News Online) — A preventive full-body MRI that appears to have found a brain tumor before symptoms began is the kind of story that can make elective screening sound persuasive. But federal regulators and major medical groups say that, for most healthy people, the scans still have not been shown to do more good than harm.
For people deciding whether to pay for one of these scans, the key question is not whether an MRI can ever find something serious. It can. The bigger question is whether scanning the whole body in people without symptoms actually helps them live longer or better.
What is a full-body MRI?
A full-body MRI is a scan that images many organs and tissues at once, often as a preventive service rather than a test ordered for a specific symptom. The American Cancer Society says MRI does not use ionizing radiation, unlike CT scans.
That does not make the scan risk-free. The Cancer Society says whole-body MRI can show “spots” or “shadows” that turn out to be normal variations, which can lead to more tests, biopsies or procedures. The organization says insurance companies rarely pay because the scans are not part of standard medical care.
Why are doctors cautious about routine screening?
The Food and Drug Administration says it knows of no scientific evidence showing that whole-body scanning of people without symptoms provides more benefit than harm. The American College of Radiology says there is insufficient evidence to recommend total-body screening for people with no symptoms, risk factors or family history suggesting disease or serious injury.
The American Academy of Family Physicians and the American College of Preventive Medicine also advise against using whole-body scans for early tumor detection in people without symptoms.
Matthew Davenport, a University of Michigan radiology professor, said in ABC News coverage of a JAMA editorial that the harms can come from “invasive testing or surgeries or follow-up of findings that are of uncertain benefit.” The editorial, coauthored by Davenport and Dr. Scott Reeder, said no major medical group recommends whole-body MRI for the general population because the benefits remain unproven.
Why San Francisco is part of the story
CBS San Francisco reported on the growing popularity of Prenuvo, a company that markets full-body MRI scans as a way to detect more than 500 conditions, including cancerous tumors at an early stage.
UCSF radiology researcher Dr. Rebecca Smith-Bindman told CBS San Francisco there is “not a stitch of evidence” that the scans help people live longer or better. She also warned that the scans could produce “tremendous numbers of false positives” and lead to follow-up testing that may not help patients.
That is why the debate matters locally. In a health-conscious market like San Francisco, the appeal of a preventive scan is easy to understand. But the local medical message is still cautious: finding something early is only helpful if the test does not create more harm than benefit along the way.
Does one dramatic case settle the question?
No. Fox News reported on a former “Bachelor” contestant who said a preventive scan found a brain tumor before symptoms appeared. But the report did not identify the person or give details about the tumor type, treatment or outcome.
A single case can show that a scan found an abnormality. It does not show that the scan should be used routinely for people who are otherwise healthy.
What are the main downsides?
The most common concerns are false positives, incidental findings, anxiety, extra testing, overdiagnosis, overtreatment and false reassurance. Cleveland Clinic says there is also a risk of overdiagnosis, meaning a condition is found that would not have caused major symptoms or death.
That is the tradeoff doctors keep pointing to: a scan may uncover a real problem, but it may also uncover a harmless one, or create a cascade of more tests with uncertain benefit.
For now, the evidence-based bottom line is simple. Full-body MRI may sound reassuring, and in some cases it may find disease early. But major medical groups and the FDA say there is still not enough proof to support routine screening of people without symptoms or special risk factors.
