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Photon dose calculation of a three‐dimensional treatment planning system compared to the Monte Carlo code BEAM
Author(s) -
Francescon Paolo,
Cavedon Carlo,
Reccanello Sonia,
Cora Stefania
Publication year - 2000
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 - 10.1118/1.599024
Subject(s) - monte carlo method , imaging phantom , linear particle accelerator , radiation treatment planning , dosimetry , photon , beam (structure) , physics , convolution (computer science) , computational physics , nuclear medicine , optics , medical physics , radiation therapy , computer science , mathematics , statistics , medicine , machine learning , artificial neural network
The purpose of this work is to compare the photon dose calculation of a commercially available three‐dimensional (3D) treatment planning system based on the collapsed cone convolution technique against BEAM, a Monte Carlo code that allows detailed simulation of a radiotherapy accelerator. The first part of the work is devoted to the commissioning of BEAM for a 6 MV photon beam and to the optimization of the linac description to fit the experimental data. This step also involves a comparison with radiochromic film data on an inhomogeneous phantom built to simulate electronic nonequilibrium conditions. Commissioning the selected photon beams required a careful description of the treatment head and the fine tuning of physical parameters such as electron beam energy and radius. The second part shows the dose comparison for real patient's CT data sets: A mediastinal treatment and a breast treatment were simulated. Doses in terms of absolute values per monitor unit were calculated based on the BEAM simulation of the CT data sets. For comparisons of real‐patient cases, differences between the treatment planning system and BEAM ranged from 0 to 2.6% and were within ±2 standard deviations for the dose calculated at the prescription point. Dose‐volume histogram analysis indicated that there is no consistent difference between the Monte Carlo and the convolution calculations. On the basis of the results presented in this study, we can conclude that the CCC algorithm is capable of giving results absolutely comparable to those of a Monte Carlo calculation, as far as common 3D radiotherapy planning is concerned.