Tumour polyp detection using random lasing

Abstract

Tumors arise from the uncontrolled growth of cells and can be benign or cancerous. The size of the tumor is one of the key factors in assessing its malignancy potential. Generally, larger tumor polyp tends to have higher risk of developing into a cancer. Smaller polyps often start benign but some of it evolve over time to adenomatous or cancerous and extend to other parts of the body. To mitigate this risk, even smaller polyps are usually removed if found during screening. However, the detection of small polyps, especially flat or sessile types, remains a challenge. Advanced techniques are being developed to identify early-stage tumors by studying biomechanical, biochemical, and morphological changes. Tumor progression alters the viscoelasticity, local refractive index, and surface roughness, increasing tissue disorder both structurally and optically. This disorder can localize light through multiple scattering and can be utilized to provide cavity feedback for lasing emission called 'random lasing'. In this work, we simulate a tumor polyp growth in a phantom tissue impregnated with a gain medium and investigate the resulting random lasing emission. We find that the emission properties such as the intensity, lasing threshold, emission wavelength, and linewidth are all influenced by the presence of the polyp and this technique could precisely identify even polyps of size ~ millimeters. Overall, this research showcases the potential of random lasing to investigate disorder-induced changes for early and sensitive detection of tumor and identification of tissue abnormalities.