Enhanced epithelial fluorescence sensitivity using an oblique-angled fiber optic probe for epithelial cancer diagnosis: a modified Monte Carlo simulation study

This study aims to analyze spatially resolved fluorescence for probing various depths of the epithelial tissue using an optimized illumination and collection configuration. The enhanced epithelial sensitivity enables precise detection of alterations in the tissue’s optical properties associated with disease progression. The elastic scattering and fluorescence of a cervical tissue-mimicking phantom were simulated using the Monte Carlo method, which was modified to incorporate oblique illumination, oblique collection, and the propagation of fluorescence photons. The results demonstrate that oblique illumination and collection in a parallel configuration (O-O-P) exhibit high epithelial sensitivity at both small and large source–detector separations. Additionally, spatially resolved fluorescence enables high-sensitivity probing of various depths within the epithelium layer. We modeled a fiber-optic probe employing an O-O-P configuration with 45° beveled fibers. It was observed that this multi-collection fiber-optic probe effectively differentiates cervical precancer grades by analyzing fluorescence intensity variations, which correspond to changes in tissue optical properties during disease progression.