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Po‐Thur Eve General‐04: Squeezing a balloon: the co‐dependences of calculated photon beam characteristics on model parameters
Author(s) -
RangelBaltazar A,
Ploquin N,
Kay I,
Doll C,
Dunscombe P,
Baker Tom
Publication year - 2006
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2244631
Subject(s) - beam (structure) , pinnacle , photon , optics , feature (linguistics) , physics , penumbra , computational physics , radiation treatment planning , medicine , cardiology , linguistics , philosophy , ischemia , radiation therapy
Modeling photon beams in modern treatment planning systems is an iterative procedure as the model parameters generally influence the behaviour of more than one feature of the computed beam characteristics. In this work we explore the co‐dependence of the calculation of specified regions of beam profiles on the adjustable source parameters in Pinnacle®. The regions chosen are those used by Venselaar in recommending tolerances to be applied during the modeling process. A reference model, at 15MV, was modified in a controlled fashion so as to primarily influence one region of either the depth dose or cross beam profile at 10cm depth in a 20×20cm 2 field. The effect on the five other profile regions was examined thus illuminating the degree of co‐dependence of the different regions on the model parameters. The regions of interest were: build‐up, descending depth dose, horns, tail, high and low penumbra. Our study suggests a sequence which could enhance efficiency in modeling measured photon beam data.