Temporal Variation of Local Fluorescence Sources in the Photodynamic Process

Photodynamic Therapy is an optical treatment modality with promising results to overcome different types of non melanoma skin cancers. Predictive models have become a valuable tool to mimic a real treatment situation and therefore offer the possibility to anticipate the therapeutic response under different clinical scenarios. Regarding photodynamic therapy this is especially important due to actual clinical protocols do not allow to adjust the treatment parameters to provide a custom therapy for non melanoma skin cancer. Despite the fact that inter patients responses vary even under the same fixed dosimetric parameters, nowadays the clinical protocol is applied in the same manner regardless of the patient variability or the type of lesion. This paper presents a predictive model for photodynamic therapy that takes into account the main photophysical and photochemical processes involved in this treatment as well as the generation of the photosensitizer fluorescence. Afterwards the model is applied to different skin tumors and the fluorescence power emission is obtained. The results show the spatial and temporal variation of fluorescence emission sources as the treatment progresses. Future works will deal with the distribution of the fluorescence signal in an heterogeneous media taking into account the sources of fluorescence here obtained.