Calculation of photon dose distributions in an inhomogeneous medium using convolutions

A formulation of the single energy photon transport problem is cast in the form of a series of convolutions over the primary fluence distribution with invariant kernels. A method is developed for compensating for the variant intervoxel attenuation in the scattered dose distribution by means of an invariant correction kernel. Results of applying the formulation to 60Co distributions in the presence of slab and block inhomogeneities are presented.