Study of factors mediating effect of photodynamic therapy on bladder in canine bladder model

The canine bladder model was employed to study the factors mediating the effect of photodynamic therapy (PDT) on the bladder. The recovery (time taken for the bladder volume to return to pre-PDT value), gross and microscopic findings, implicate both bladder high filling pressure (60 cm H2O) and high light dose as factors mediating the effect of photodynamic therapy on bladder capacity. We recommend that photodynamic therapy to the bladder be performed under a filling pressure of 30 cm H2O, which is physiologic, and whole bladder illumination at a light dose not greater than 30 J/cm2.