Optical method using fluence or radiance measurements to monitor thermal therapy

We present data from a two-region (coagulated and native tissue) Monte Carlo simulation in spherical geometry to assess the feasibility of using optical fluence and radiance information for determining the boundary of tissue coagulation during thermal therapy. Our results demonstrate that radiance offers directional sensitivity that might be useful in monitoring asymmetric coagulation growth. Preliminary experimental data from fluence monitoring of radio-frequency kidney thermal therapy further indicates that fluence information might be insufficient for determining the coagulation boundary. Therefore, in addition to optical fluence, we are also exploring the potential of radiance monitoring as a method for establishing the position of the coagulation boundary during radio-frequency thermal therapy. (C) 2003 American Institute of Physics.