Clinical instrument for spectral diagnosis of cutaneous malignancy

Abstract

We present a novel probe-based portable clinical system for early detection and margin demarcation of melanoma and non-melanoma skin cancers. The system collects both white light reflectance and fluorescence from tissue in real time. We use gated detection to eliminate effects of room lights and make the system clinically compatible. Instrument control and spectral calibration is automated using a personal computer. The total acquisition time for data collection is less than a second. We use a spectrally-constrained inverse model for our probe geometry to fit the diffuse reflectance and extract hemoglobin content, oxygen saturation, tissue micro-architecture and melanin content. We demonstrate system performance and present results from tissue simulating phantoms. The mean rms errors in estimating scattering and absorption coefficients in tissue phantoms over a physiologically relevant range were 9.8% and 11.8% respectively. Using a photon migration model and least-squares regression we were able to extract the intrinsic fluorescence line shapes and estimate fluorophore concentrations from measured fluorescence spectra with an rms error of less than 10%.