Brief Description:Since 2003, a collaborative research effort between researchers at the University of Rochester Medical Center (URMC) and the Roswell Park Cancer Institute (RPCI) has resulted in the development of a system for delivery of photodynamic therapy(PDT) for the treatment of cancer with capabilities for realtime spectroscopic monitoring and feedback controlled dosimetry.Applications:This invention involves instrumentation developed for delivery of spatially resolved photodynamic therapy (PDT) in vivo, employing real-time measurements of fluorescence emission spectra corrected for effects of dynamic tissue optical properties using white light diffuse reflectance. It accurately measures photosensitizer bleaching, photoproduct formation and tissue oxygenation all of which are useful as dosage metrics.The system is applied in measurement of dosage delivery through photodynamic therapy to skin and retina or through endoscope to lungs, esophagus, cervix etc. It is compatible with Raman spectroscopy for inspection of blood and tissue analytes such as glucose.The instrumentation is comprised of a set of light sources, fiber optic switches, a shutter, two spectrometers, an optical probe, an optical filter, circuitry, housings, and a computer.Advantages:The system provides in vivo characterization of endogenous and exogenous fluorophores. The use of fiber optic switches provides a faster, more compact, and more stable integration of light sources. In addition, the instrumentation is designed to allow for more functionality and spatial resolution through multiplexing of multiple signal sources. Feedback in the form of fluorescence spectra analyzed in realtime enables continuous monitoring of dosage levels to improve efficacy, reduce or eliminate pain associated with therapy and alleviate or eliminate the need for anesthetics or continuous sedation of patients undergoing PDT. This also has the effect of minimizing treatment time in the clinic. Optimized dosimetry also takes into account measured patient pain thresholds.Technology Status:To date, the instrumentation has been successfully used in two clinical research trials to optimize PDT dosimetry.