Exploratory Approach Using Laser-Induced Autofluorescence for Upper Aerodigestive Tract Cancer Diagnosis—Three Case Reports

Laser-induced autofluorescence (LIAF) spectroscopy is a label-free optical technique sensitive to biochemical and structural tissue properties. Its application in upper aerodigestive tract malignancies is in its early stages. This study evaluates the feasibility of a matrix scan-based LIAF approach for examining differences between normal and malignant tissues. An exploratory case series involving three patients with oropharyngeal malignancies was conducted. Tissue sections from normal and tumor regions were analyzed using LIAF spectroscopy, including intensity and lifetime measurements, implemented through a matrix scanning protocol with fixed excitation, detection sensitivity, and sample thickness. Complementary Fourier-transform infrared (FTIR) spectroscopy was used to qualitatively assess biochemical variations, and spectroscopic findings were correlated with histopathological evaluation. Within individual cases, consistent differences in autofluorescence spectral and lifetime characteristics were observed between benign and malignant tissue regions. FTIR analysis revealed concurrent biochemical variations that qualitatively supported the autofluorescence observations. This exploratory study demonstrates the potential of combining LIAF matrix scan with FTIR spectroscopy to investigate tissue-specific spectral variations in upper aerodigestive tract lesions. The findings are preliminary and motivate further investigation using larger patient groups and clinically relevant acquisition conditions.