Advantages and limitations of the autofluorescent diagnostics of the laryngeal cancer and precancerosis

Any endoscopic diagnostic procedure that is capable of giving exact information on laryngeal lesions without damaging the tissue has essential advantages over standard biopsy. Tissue autofluorescence is defined as a natural ability of tissue to fluoresce when exposed to a certain light wavelength. This feature is a consequence of the presence of fluorophores in the tissues, which are activated by a narrow wavelength range. However, due to their biochemical and biophysical characteristics, laryngeal precancerosis and cancer do not fluoresce when exposed to blue light. In the present study, we used Pentax's System of Autofluorescent Endoscopy (SAFE 1000) to detect autofluorescence disturbances from laryngeal mucosa. Diagnostic parameters (sensitivity and specificity) of the microlaryngoscopy (MLS) and SAFE 1000 in the diagnosis of laryngeal precancerosis and carcinoma were compared and discussed. We have found that SAFE had a better sensitivity with regard to mentioned laryngeal pathology, but MLS had better specificity than SAFE. The overall diagnostic sensitivity in the diagnostics of laryngeal atypical hyperplasia and cancer with SAFE was 89%, as opposed to 73% with MLS. Diagnostic specificity of SAFE for all cases of laryngeal carcinomas and atypical hyperplasia was 78%. The specificity of MLS in diagnostics of laryngeal carcinomas cases was 98%, while that for cases of atypical hyperplasia was 100%. Many other conditions that have impact on autofluorescent features of laryngeal mucosa were also discussed.