Identification of tumor margins using diffuse reflectance spectroscopy with an extended‐wavelength spectrum in a porcine model

Abstract

A novel extended-wavelength diffuse reflectance spectroscopy (EWDRS) technique is being developed for future clinical non-invasive tumor margin delineation. In this study, the ability of EWDRS to identify the margins of pigmented skin lesions in an in vivo pig model was evaluated. Extended-wavelength diffuse reflectance spectroscopy recordings (350-1550nm) were made on 13 pigmented skin lesions and non-pigmented skin, as a reference. The hand-held probe was swept toward the pigmented area until the signal changed, thus indicating that the margin had been identified. A needle was inserted as a marker, and tissue samples were sent for histological analysis. The distance between the EWDRS-defined border and the histological border was measured by 3 independent examiners. The median difference between the EWDRS-defined border and the histological border was 70μm toward the pigmented tissue (range: -579 to 538μm). A Pearson correlation coefficient of .95 was obtained for the examiners. Extended-wavelength diffuse reflectance spectroscopy can be used in vivo to delineate the border of pigmented skin lesions in a porcine model with high accuracy, indicating that it may be a useful tool for non-invasive tumor margin delineation in the future.