The Dilemma of Incidental Findings

11. November 2008

Who participates in a study, sometimes learns about results neither expected nor welcome. The studying person faces a difficult decision and the question arises: How do I explain that to my test person?

“It was in the mid nineties when a student of a well-known university participated in a magnetic resonance imaging study. Since only few scanners of four Tesla existed, the study was purely experimental. The operators did not have a clinical expert check the scans. A few years after this unsuccessful study – it was never published – the student suffered from an epileptic seizure. During neurological and neurosurgical examinations they found a brain tumor. On the MRI image, the neurologist discovered the tumor and assumed it had been there since birth.” The sample came from Charles Nelson of Harvard University. And it shows the problems which might occur with supposedly healthy test persons during a study.

Every fourth brain is not “normal”

Not always, a participant in a study can rely on it that the image or the test will reveal any veiled diseases. “Why did I not come to know? A doctor has to see that!” says the test person feeling as the patient. But this is exactly what he is not – say medical ethicists. In the process of technical development, computer tomography or MRI are getting more and more popular.

The monitor displays in different colors, what a curious look or the picture of a prominent person effects in the brain. At this, the conclusions of the researchers are frequently closer to speculations than to the truth. For both, the spatial and the temporal solution of a nuclear spin image is very roughly. The detectors capture several million nerve cells per measuring point, while neurones fire their potentials in hundredth-cycles tuned to second. In many cases it lacks in expertise: According to a survey done by Anton Valavanis at the Neuroradiology Zurich/Switzerland, round about 30 percent of all fMRT-images were mismatched anatomically. But sometimes structures pop up on the image the researcher wasn’t even looking for. About a year ago, Meike Vernooij and her colleagues at the Rotterdam University have submitted elementary data regarding unexpected brain results in the New England Journal of Medicine. In about 7 percent of approximately 2,000 MRI scans they found asymptomatic brain strokes, in addition to aneurysms (1.8%) and benign primary tumors (1.6%). In Germany, reliable figures based on 2536 young men originate from the Institut für Luftfahrtmedizin in Fuerstenfeldbruck (institute for aviation medicine). During medical examination for the military aviation service, only about 75 percent of the results were “normal”. 18 percent of the examined showed discrepancies from standard. 14 cases needed clarification urgently.

Revealed escapades

Here researchers specifically searched for discrepancies without any earlier suspicion. But how do researchers without clinical experience proceed with “strange” results in MRI images? A study of Judy Illes from Vancouver/Canada provides some answers: Seven out of ten participants of a questionnaire campaign in 27 countries engage a specialist in case of suspicious results, 13 percent have all images examined, the rest does not cooperate with neurology. At the American National Institute of Health a neuroradiologist takes a look at every MRI image by now.

Incidental findings do not only appear in neurology. Every now and then it turns out during genetic family examinations, that the supposed family member is the result of an escapade or an earlier relationship. Or the person carries a risk gene for a severe illness. Sometimes an unexpected spot at the lung base appears on CT-images of the colon. And every now and then serious changes come to light the colleague was not able to discover several years ago.

Initial guidelines for incidental findings

But does the study participant want to know all those things? Is he just about to secure his family with a life insurance? How should the study participant handle incidental findings? Thomas Heinemann and Christian Hoppe at the Bonn University thought about it. In their report for the Deutsche Ärzteblatt (German newspaper for physicians, they put emphasis on the differentiation between physician and researcher. The head of the studies should point out to his test persons prior to the studies that incidental findings might occur. On the other hand, the participant decides whether he wants to know about it. The participation in a study does not go with the right to a professional expertise. Not always does the budget allow an expert control of the images or tests.

Neither in Germany nor in the US are any regulations for the handling of results one did not actually look for. In May 2007, a meeting of experts took place where guidelines for researchers were developed:

  • At the signs of a life-threatening disease or a severe but treatable disease, the responsible should try at any rate to inform the test person. That also applies to according risks for children in case of a planned family addition.
  • On his or her own responsibility the researcher may reveal the results if it points to a severe but not treatable disorder. This also applies for a disease which might influence the wish for children.
  • Against a disclosure – unless the participant has decided for it – speak results with unclear meaning or for example an indication of inexplicit parenthood.

A clinical study is no diagnosis. Both sides need to be aware of that. And the lucky one without any results is far from being the proud owner of a carte blanche regarding his or her health.

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