We describe an instrument which will permit simultaneous collection of radial resolved reflectance over the spectral range 600-1000 nm and a neural network algorithm which permits real- time analysis of the data. The in vivo performance of the instrument is presently under investigation. Data will be presented illustrating the performance of the instrument over the useful optical spectrum for certain tissues of interest. In addition the derived tissue concentrations of photosensitizers will be compared with those obtained using chemical extraction techniques on excised tissue samples.