Differences in autofluorescence (fluorescence without photodynamic drugs) between normal and malignant tissues offer new
possibilities in detecting and localizing early laryngeal carcinoma. Autofluorescence imaging was performed using a modified
fluorescence endoscopy system from Xillix Technologies (Richmond, Canada). Fluorescence was induced by blue light at 442 nm
and captured by an image-intensified camera through a laryngeal telescope. The images were then processed by the system and
displayed on a video monitor. Normal tissue appeared green while malignant sites appeared reddish-brown. The autofluorescence
imaging technique was compared to standard microlaryngoscopy in 108 patients with laryngeal pathologies (in 74 of whom malignancy
was suspected). The acquired reflectance and fluorescence images of each lesion were assessed independently as malignant or
not malignant by three ENT specialists who were familiar with the procedure but were not provided with clinical data or histopathological
information concerning the lesion. The assessments of pathology were determined from the two imaging modalities and were compared
to histopathological findings of the biopsy specimens taken from the lesion. The present study showed that autofluorescence
imaging can be a useful complementary method to microlaryngoscopy for detecting and delineating laryngeal malignancies. If
in the future, the device can be developed for use in an outpatient office, a significant improvement can be made for the
early detection of laryngeal malignancies.
Key words Laryngeal cancer - Diagnosis - Autofluorescence
Received: 11 January 1999 / Accepted: 23 February 1999