title: [Accuracy of distribution of the doses obtained with electron beams of irregular shape and in the presence of inhomogeneous structures].
abstract: The authors have addressed the problem of dose distribution calculation accuracy when irregularly shaped electron beams are used and structural dishomogeneities are present. The mathematical model used for the electrons from the "scattering foil" and from the colimator walls is the "gaussian pencil beam", and the total dose is obtained by adding to the above mentioned components the dose from the electrons diffused by the field defining frame and from bremsstrahlung photons. Depth dose curves, with and without frames, are compared with a satisfactory correspondence between the calculated and the measured curves. The calculation method is considered accurate within 2% of dose and 2 mm in position. When dishomogeneous structures are present and treated as semi-infinite layers, corrections are referred in 2-D to a single anatomical section and can be extended to 3-D if a sufficient number of sections is available for the whole volume definition. However current algorithms need to be improved when there is the possibility to use a much more powerful hardware.
authors: Servizio di Biofisica, Istituto Nazionale per la Ricerca sul Cancro, Genova.
authors: L
authors: L
authors: Andreucci
authors: G
authors: G
authors: Ghiso
authors: I
authors: I
authors: Riccardi
authors: A
authors: A
authors: Schenone
mesh_terms: D000465:Algorithms; D004583:Electrons; D006801:Humans; D009686:Nuclear Physics; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage
vernacular_title: Accuratezza delle distribuzioni di dose ottenute con fasci di elettroni di forme irregolari e in presenza di strutture disomegenee.