Autofluorescence and diffuse reflectance spectroscopy for oral oncology

Area of Science:

• Biomedical Optics
• Diagnostic Spectroscopy
• Oral Pathology

Background:

• Autofluorescence (AF) and diffuse reflectance spectroscopy (DRS) are established tissue diagnostic techniques.
• Previous studies evaluated AF for oral (pre)malignancy classification.
• This study investigates the combined diagnostic contributions of DRS and AF.

Purpose of the Study:

• To determine the diagnostic performance of diffuse reflectance spectroscopy (DRS) and autofluorescence spectroscopy (AF).
• To assess the contributions of DRS and AF, individually and combined, in classifying oral lesions.
• To differentiate between healthy oral mucosa, all lesions, and specific lesion types (benign vs. dysplastic/malignant).

Main Methods:

• Collected AF and DRS spectra from 172 oral lesions and 70 healthy volunteers.
• Corrected AF spectra for blood absorption using DRS.
• Applied Principal Components Analysis (PCA) with classifiers to distinguish lesion categories.
• Evaluated AF and DRS spectra separately and in combination.

Main Results:

• Excellent classification of cancer vs. healthy mucosa (ROC areas up to 0.98) for both DRS and corrected AF.
• Successful classification of all lesions vs. healthy mucosa (ROC areas up to 0.90) for both techniques.
• Limited success in classifying benign vs. (pre)malignant lesions (ROC areas <0.70 for AF, <0.77 for DRS).
• Combining AF and DRS showed only marginal improvement.

Conclusions:

• DRS and corrected AF provide similar diagnostic performance for differentiating oral lesions from healthy tissue.
• Blood absorption and scattering information, along with corrected AF, are key for lesion detection.
• Neither technique, alone or combined, can reliably distinguish benign from dysplastic/malignant oral lesions.