Reflectance imaging spectroscopy: possible aid in the clinical diagnosis of melanoma

Reflectance spectrophotometry allows an objective evaluation of surface colors and it has been proposed as a tool to discriminate cutaneous melanoma from other pigmented cutaneous lesions. In order to improve reflectance spectral analysis of moles, a novel spectrophotometric system has been developed, based on the use of a CCD camera provided with a set of interference filters. For each filter the system acquires an image of the lesion. The images are digitized and stored in a PC for off-line data handling. Reflectance images from visible to near IR were acquired of 51 cutaneous pigmented lesions including melanoma and dysplastic, compound and junctional nevus. Four reflectance standards were used to convert the image raw numbers into absolute reflectance values. From each spectral image, corresponding to a selected wavelength, four parameters were derived to quantify color, pigment distribution, dimension and boundary of each lesion. A statistical analysis performed on the selected parameters shows that the mean effective reflectance, pigment distribution and lesion area are significantly different when melanoma is compared to the other lesions. This result suggests that telespectrophotometry could be used as an aid in performing clinical diagnosis of melanoma.