Characterization of a murine model for the rapid assessment of acute photodynamic response in tumour and muscle.

A murine implanted colorectal tumour model is described in which a measurement of tumour depth of necrosis is combined with a simultaneous measurement of muscle damage. The response of this model to a range of photodynamic therapy parameters was characterized using the chlorin photosensitizer mTHPC (temoporfin, Foscan®R). Both tumour depth of necrosis (measured directly and on histology) and muscle swelling correlate with the dose of photosensitizer and light, and are shown to be repeatable and consistent with published values obtained under similar conditions using established models.