Abstract

The absorption properties of photosensitizers for the photodynamic therapy of tumors (PDT) may be significantly influenced by their interactions with the biological substrate, leading to an in vivo spectrum, which cannot be predicted on the basis of in vitro studies. Therefore, for the development of an optimized clinical protocol, it is fundamental to estimate the absorption spectrum in vivo non-invasively, thus determining the best irradiation wavelength. This measurement can be performed by means of time-resolved reflectance, which allows to evaluate both the absorption and the scattering coefficients, and therefore provides also information on the light penetration in tissues, useful to define the optimal light dose for therapeutical purposes.

© 1994 IEEE