Download Citation on ResearchGate | On Jan 1, , D. W.O. Rogers and others published BEAMnrc users manual }. BEAMnrc: software tool to model radiation beams. BEAMnrc is now part of EGSnrc. Report a problem or mistake on this page. Please select all. BEAMnrc, DOSXYZnrc and BEAMDP GUI users manual.
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The percentage difference between measured and a selection of MC calculated central and off-axis dose profiles is also shown. The three options for bremsstrahlung photon splitting were used in this study, i. The percentage difference, in the central region of the field and at different depths, between measured and a selection of MC calculated off-axis dose profiles is also shown.
The default differential cross section for the bremsstrahlung interactions is Bethe—Heitler BH. Therefore, the actual relative efficiencies possible with DBS were underestimated. Variance reduction techniques Bremsstrahlung photon splitting, Russian Roulette, and electron splitting The three options for bremsstrahlung photon splitting were used in this study, i.
BEAMnrc: software tool to model radiation beams
The following efficiency enhancing methods were considered: VRTs do not change the physics and therefore do not bias the results. Three main areas were considered. An additional phantom with a 5 cm air gap embedded in water was also simulated for dose computations.
Estimates of the uncertainty using a significant number of bins e. Springer-Verlag, Heidelberg,pp.
BEAMnrc: software tool to model radiation beams – National Research Council Canada
In addition, the methods for performing the efficiency and statistical uncertainty calculations are described. It is generally accepted that the cross-section data available in the megavoltage energy range are sufficiently accurate. The CPU times were scaled to a single 2. With photon interaction forcing, the user can force photons to interact up to a user-defined number of times, Nin specified component modules within a simulation.
In addition, the relative efficiencies are dependent on the quantity of beanmrc chosen, although manyal can claim from this study that BEAMnrc MC calculations with the directional bremsstrahlung splitting technique yields the highest efficiency for all quantities of interest analyzed.
BEAMnrc, DOSXYZnrc and BEAMDP GUI users manual – NRC Publications Archive –
Photon and bremsstrahlung cross sections The current version of BEAMnrc allows the user to choose three different photon cross sections: This is a technique, recently introduced in BEAMnrc18 that is more efficient than the standard range rejection scheme just described. For the first three uncertainty calculations, only one bin is considered, i. On the other hand, the scattered photon can be forced to interact again in the forcing zone, depending on how many forced interactions are still available.
The percentage difference, in the central region of the field and at different depths, between the two MC calculated data is also shown.
Open in a separate window. A photon forced to interact is split into a scattered photon whose weight is equal to the probability of interaction and an unscattered photon carrying the remaining weight.
However, as demonstrated in Sec. Monte Carlo MC simulation techniques are presently considered to be the most reliable method for radiation therapy treatment planning. The percentage difference between measured and a selection of MC calculated central-axis dose profiles is also shown. Academic, New York,Vol. An investigation of the influence of different photon and bremsstrahlung cross-section data available in BEAMnrc on the accuracy of calculated fluence and dose distributions.
Medical Physics, Windsor,pp. Author information Article notes Copyright and License information Disclaimer. On the manuzl hand, if one is interested in the most efficient PS simulation note that efficiency is the inverse product of variance and timethen it is necessary to use VRTs.
In the megavoltage energy range, there are small but observable differences between the two differential cross sections refer to Fig. If one uses VRTs e. The current version of BEAMnrc allows the user to choose three different manuak cross sections: Augmented range rejection accounts correctly for bremsstrahlung production, since charged particles surviving Russian Roulette and with their weight increased by a factor of NBRSPL still have a chance to undergo bremsstrahlung events.
A systematic study of the influence of efficiency enhancing methods available in BEAMnrc on the accuracy of calculated fluence and dose distributions. Data Tables 35 3— If the fluence distributions were reconstructed using equal area scoring zones e. The mean energy and planar fluence were extracted from the PHSP in circular ring bins of equal area, the spectral distribution in energy bins of equal bin width, and the angular distribution mankal angular bins of equal bin width.
The photon forcing parameters can also be passed onto secondary photons and veamnrc feature is particularly useful to improve amnual efficiency for bremsstrahlung photon interactions, especially when combined with bremsstrahlung photon mznual.
With SBS, the value of NBRSPL is changed in order to maximize the splitting of photons aimed into the field and to minimize unnecessary splitting of photons beamnrf away from the field.
Support Center Support Center. Monte Carlo transport parameters Maximum electron step, smax cm 10 Maximum electron loss per step MeV 0.