Influence of initial electron beam parameters on Monte Carlo calculated absorbed dose distributions for radiotherapy photon beams

2004 ◽  
Vol 31 (4) ◽  
pp. 907-913 ◽  
Author(s):  
Antonis Tzedakis ◽  
John E. Damilakis ◽  
Michael Mazonakis ◽  
John Stratakis ◽  
Haralambos Varveris ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Absorbed Dose ◽  
Photon Beams ◽  
Dose Distributions ◽  
Initial Electron ◽  
Beam Parameters

Benchmarking of Monte Carlo model of Siemens Oncor® linear accelerator for 18MV photon beam: Determination of initial electron beam parameters

2020 ◽  
Vol 27 (6) ◽  
pp. 1047-1070
Author(s):  
Milad Najafzadeh ◽  
Mojtaba Hoseini-Ghafarokhi ◽  
Rezgar Shahi Mayn Bolagh ◽  
Mohammad Haghparast ◽  
Shiva Zarifi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Linear Accelerator ◽  
Monte Carlo Model ◽  
Photon Beam ◽  
Initial Electron ◽  
Beam Parameters

Decoupling initial electron beam parameters for Monte Carlo photon beam modelling by removing beam-modifying filters from the beam path

2005 ◽  
Vol 50 (24) ◽  
pp. 5935-5951 ◽  
Author(s):  
B De Smedt ◽  
N Reynaert ◽  
F Flachet ◽  
M Coghe ◽  
M G Thompson ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Photon Beam ◽  
Beam Path ◽  
Initial Electron ◽  
Beam Parameters

scholarly journals Electron contamination for 6 MV photon beams from an Elekta linac: Monte Carlo simulation

2020 ◽  
Vol 2 (2) ◽  
pp. 97-101
Author(s):  
Choirul Anam ◽  
Djarwani S Soejoko ◽  
Freddy Haryanto ◽  
Sitti Yani ◽  
Geoff Dougherty
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Intensity Distribution ◽  
External Beam Radiotherapy ◽  
Absorbed Dose ◽  
Field Size ◽  
Photon Beams ◽  
Initial Electron ◽  
Depth Dose ◽  
Air Column

In external beam radiotherapy, the photons from a linear accelerator (linac) machine undergo multiple interactions, not only in the patient but also in the linac head and the air column between the linac head and the patient. Electrons are released from these interactions and contaminate the beams. The current study evaluates electron contamination for 6 MV photon beams from an Elekta linac using Monte Carlo simulation. The linac head was simulated by the BEAMnrc code and the absorbed dose in a phantom was calculated using the DOSXYZnrc code. The parameters of the initial electron beams on the target, such as mean energy and radial intensity distribution, were determined by matching the calculated dose distributions with the measured dose (at 10 x 10 cm2 field size and 90 cm source-skin distance). The central axis depth-dose curves of electron contamination were calculated for various field sizes from 5 x 5 cm2 to 40 x 40 cm2. We investigated the components that generated the electron contamination for a field size of 10 x 10 cm2. The optimal initial electron beam energy was 6.3 MeV with a full-width half maximum (FWHM) of the radial intensity distribution of 1.0 mm. These parameters were found to be in good agreement with the measured data. Electron contamination increased as the field size increased. At a depth of 1.0 mm and field sizes of 5 x 5, 10 x 10, 20 x 20, 30 x 30, and 40 x 40 cm2, the doses from electron contamination were 3.71, 5.19, 14.39, 18.97 and 20.89 %, respectively. Electron contamination decreased with increased depth. At a depth of 15 mm, the electron contamination was about 1 %. It was mainly generated in the air column between the linac head and the phantom (3.65 %), the mirror (0.99 %), and the flattening filter (0.59 %) (for the depth of 1.0 mm and the field size of 10 x 10 cm2).

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