In-vivo photodynamic therapy dosimeter

A fiberoptic isotropic probe system has been developed to measure both the Space Irradiance (SI) and Fluorescence (F) within tissue during Photodynamic Therapy (PDT). The probe is 0.8mm in diameter. The system has a SI sensitivity of 0.1 mW/cm2 and a F sensitivity of 0.1 microgram per milliliter of DHE in a tissue phantom solution. It also provides for the time integrated SI and F and a ratio of the F to SI. A biological response study is being undertaken using DHE to determine the correlation of therapeutic response with drug dose, light dose, integrated space irradiance, and integrated fluorescence in a standardized animal tumor model. Description of the device and its performance will be presented along with preliminary results of animal tumor model studies.