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

OBJECTIVE

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.

MATERIALS AND METHODS

Extended-wavelength diffuse reflectance spectroscopy recordings (350-1550 nm) 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.

RESULTS

The median difference between the EWDRS-defined border and the histological border was 70 μm toward the pigmented tissue (range: -579 to 538 μm). A Pearson correlation coefficient of .95 was obtained for the examiners.

CONCLUSIONS

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.