Monte Carlo Simulation of Light Propagation In Oral Tissues for Photobiomodulation Therapy
Abstract
Purpose
Radiation-induced oral mucositis (OM) is a severe complication in head and neck cancer patients, significantly impacting quality of life. While Photobiomodulation (PBM) is a promising non-invasive management strategy, clinical protocols remain inconsistent regarding wavelength and dosage. A primary barrier to standardization is the limited understanding of light propagation within the complex geometry of the oral cavity. This study aims to utilize Monte Carlo (MC) simulations to characterize light propagation and provide insights to optimize PBM dosing specifically for OM treatment.
Methods
We utilized Monte Carlo simulations to model light transport through anatomically realistic oral tissue structures segmented from human head and neck CT data. The study quantified the spatial distribution of light fluence, specifically characterizing the interaction between soft tissues and underlying mineralized structures to calculate the dose delivered to the mucosal basal layer for OM management.
Results
The simulations demonstrated that light scattering and absorption properties significantly alter the effective fluence delivered to the mucosa compared to surface irradiance. We identified distinct differences in fluence profiles between soft tissue and bone, highlighting the need for site-specific protocol adjustments. Crucially, the results identify tissue optical properties, incident angle, and wavelength as key determinants in balancing maximal mucosal delivery with the thermal safety of adjacent structures.
Conclusion
Monte Carlo simulation provides critical mechanistic insights into PBM dosimetry for radiation-induced oral mucositis. By quantifying light distribution in complex oral tissues, this work supports the transition from empirical to evidence-based prescription. These findings will facilitate the development of standardized, safe, and effective PBM protocols to mitigate OM in cancer patients.