Differential light scattering spectroscopy measurements for detecting and imaging cancer

Abstract

Optical spectroscopy show great promise for diagnosing the earliest stages of cancer. Light scattering spectroscopy (LSS), the study of single elastic backscattering as a function of wavelength and angle, can detect subcellular structural changes in early cancer. We have developed two novel differential light scattering spectroscopy techniques, space differential LSS (SD/LSS) and b-angle differential LSS (/LSS), for detecting the single backscattering signal from a reflectance spectrum dominated by multiple scattering and diffuse reflectance. SD/LSS exploits the penetration abilities of diffuse reflectance while /LSS exploits the angular asymmetry of single backscattering from large particles. O/LSS has the added advantage of being able to isolate single backscattering specifically from scatterers much larger than the wavelength. We implement /LSS to interrogate colon tissue and to develop diagnostic algorithms based on Mie theory. The results show great promise for diagnosing cancer. Instrumentation is being developed to implement SD/LSS and /LSS together in a wide area imaging system with the goal of studying and detecting cancer at its earliest stages in vivo and in real time. The system has been validated with controlled tissue phantoms and will soon be ready for clinical studies.