The Application Of RGB Camera In Fluorescence Measurement Of Photosensitizer Concentration Distribution

Photodynamic therapy (PDT) is a promising therapeutic modality for both oncological and non-oncological diseases. Since the photosensitizer is one of the key elements of PDT, the PDT efficacy is influenced by the absolute concentration and distribution of photosensitizer in targeted tissue. In order to achieve personalized treatment, the development of noninvasive techniques are essential for monitoring the concentration and distribution of photosensitizer, which are necessary to further elucidate V-PDT mechanism and to predict treatment efficiency. Based on the spectral characteristics of porphyrin-based photosensitizers, the fluorescence spectroscopy and its imaging techniques were utilized to study the concentration and distribution of photosensitizer in solution and animal model in vivo, respectively. The fluorescence spectrum of photosensitizer was measured by fluorescence spectrometer, while the fluorescence images of photosensitizer was recorded with a self-developed CCD fluorescence camera. In addition, in order to elucidate the relationship among the red intensity value of fluorescence image, fluorescence intensity and the concentration of photosensitizer the fluorescence images were quantitatively analyzed by the well-established RGB color theory. The results suggest that the red intensity value of fluorescence images is positively correlated to the fluorescence intensity and the concentration of photosensitizer, as expected. In this regard, the obtained R intensity value can be used as a indicator to determine the concentration and distribution of photosensitizer. Our self-developed CCD fluorescence camera holds potential as an point-of-care device that can be used in clinical PDT treatment...