title: Dose perturbations at interfaces in photon beams.
abstract: A model based on an approximation called the partial fluence approximation is presented for the calculation of dose distributions in the vicinity of medium interfaces in photon beams. The predictions of the model are compared with dose distributions measured in layered phantoms consisting of aluminum and polystyrene, for photon beams ranging in energy from 60Co to 24 MV.
mesh_terms: D006801:Humans; D008433:Mathematics; D008962:Models, Theoretical; D011827:Radiation; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage