For the name of the procedure, the researchers working with Hubert van den Bergh and Georges Wagnières at the ETH Lausanne with their colleague Philippe Monnier at the University Hospital Lausanne, most likely will not be presented with a medal: “Diagnostic Autofluorescence-Endoscopy” * is the unspectacular name of this new diagnostic method.
But the procedure which broke ground in the late eighties within the Swiss National Research Program “Biomedical Technology” (NFP 18) would benefit from a bit more PR. This new unique diagnosis is “double as sensitive as the common endoscopic examination of the bronchia with white light” as the Swiss SNF now proclaims and informs pneumologists all over world with one beat of the drum: The early detection of bronchial cancer with a tricky wave lengths interplay is finally available on the market.
Not just any light leads to the target
Initially van den Bergh observed that healthy bronchial tissue if illuminated with light of a particular wave length naturally reflects much more intensive fluorescence light than tissue damaged in an early stage of cancer. It is exactly this difference which enables the visual detection of changes of tissue during an endoscopic examination. But not every wave length has the required diagnostic potential. Because on one hand, the light has to bring about an incisive contrast between the changes of the tissue, on the other hand the produced fluorescence radiation has to be strong enough for the following detection. “The best compromise matching both requirements synchronously was found during stimulation with violet light producing an autofluorescence in the area of green light”, the scientists explain the actual breakthrough.
But because the bronchia of man are highly ramified, the “detecting” colored rays would have left the physicians literally in the dark. So the Swiss soon realized – we need a second light source to illuminate the bronchia. The highlight: This one does not produce fluorescence radiation with red light but illuminates the bronchia. Compared to its violet counterpart, this light is reflected equally strong by healthy tissue as well as in-situ carcinoma – and therefore does not carry any diagnostic weight.
False suspicions are history
Clinical studies made by the group of Philippe Monnier at the University Hospital Lausanne confirm the reliability of the autofluorescence endoscopy at last. The spectacular result: The method detects double as much changes in tissue at an early stage of cancer than the until then common endoscopy with white light “without suspecting healthy tissue wrongly”, as the SNF now writes.
The success of the Swiss research is now to conquer hospitals and doctor’s offices with the help of a German company (Richard Wolf GmbH), up to now more than 100 devices are on duty. SNF supplies the best of all reasons for establishing this procedure with a simply look at the statistics: “The death rate after five years lays at 80 percent if detected in an advanced stage, but only at 10 percent if diagnosed in an early stage of a so-called in-situ carcinoma”. And this is exactly what can be reached with this new method – something pneumologists should bear in mind.
* Please find the demo video in an AVI-format here. (Source: Richard Wolf GmbH/SNF)