Endoluminal photodynamic therapy: Influence of tissue optical properties on light fluence in the cylindrical diffusing fibre geometry

A Monte Carlo model has been developed to simulate the fluence distribution in a fully cylindrical geometry, when a finite linear light source is placed on the axis of a hollow organ during a PDT treatment, Height and radius of the cavity, scattering and absorption coefficients (I-is and I-La), anisotropy factor (g), refractive index of medium and cavity (n(1),n(2)) are required as input by the MC code. Data obtained from this model were subsequently compared with experimental results using a tissue simulating phantom. An aqueous solution of Intralipid-1O%(R) and black ink were used to simulate optical properties. A helium-neon laser, coupled to a cylindrical diffuser was employed as light source. A good agreement between the MC simulations and experimental measurements was found.