title: An explanation of the dose inhomogeneity caused by bolus in an electron portal.
abstract: When an electron beam is incident upon a stepped surface, such as that which exists when a slab of bolus is present with it's square edge within the portal, the dose distribution is strikingly perturbed. An easily demonstrable explanation is given which utilizes the customary, flat-incident surface electron beam dose distribution.
authors.affiliation: Medical Center, Bowling Green, Kentucky 42101.
authors.forename: L W
authors.initials: LW
authors.lastname: Asp
mesh_terms: D004583:Electrons; D006801:Humans; D008962:Models, Theoretical; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage