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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Augmented charged particle range rejection is only available when used simultaneously with DBS. The percentage difference between the two MC calculated data is also shown. The percentage difference, in the central region of the bezmnrc and at different depths, between the two MC calculated data is also shown.

The photon forcing technique produces more photons, however, they are not statistically independent, thus yielding a lower efficiency although the corresponding PHSP file is generated the fastest. The CPU times were scaled to a single 2. Medical Physics, Windsor,pp. In addition, the relative efficiencies are dependent on the quantity of interest chosen, although one can claim from this study that BEAMnrc MC calculations with the directional bremsstrahlung splitting technique yields the beamngc efficiency for all quantities of interest analyzed.

An additional phantom with a 5 cm air gap embedded in water was also simulated for dose computations. In the megavoltage energy range, there are small but observable differences between the two differential cross sections refer to Fig.

Published online Nov 5. In contrast, AEITs improve efficiency through the use of approximations. This occurs because of particle correlations which are introduced with the use of VRTs, such as bremsstrahlung splitting. When changing the bremsstrahlung differential cross section from BH to NIST, the default photon cross section was used, i.

Estimates of the uncertainty using a significant number of bins e. On the other hand, the manua, photon can be forced to interact again in the forcing zone, depending on how many forced interactions are still available. The manuual advantage of using aggressive VRTs is the significant improvement in calculation time without a compromise in the accuracy of the patient dose computation. The percentage bsamnrc, in the central region of the field beamnrf at different depths, between measured and a selection of MC calculated off-axis dose profiles is also shown.

A photon forced to interact is split beamnrx a scattered photon whose weight is equal to the probability of interaction and an unscattered photon carrying the remaining weight. This work was supported in part by Grant Nos. The electron and photon cutoff energies were set to 0.

Monte Carlo MC simulation techniques are presently considered to be the most reliable method for radiation therapy treatment planning. 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. It is generally accepted that the cross-section data available in the megavoltage energy range are sufficiently accurate. A 12 195— Photon interaction forcing 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.

For the first three uncertainty calculations, only one bin is considered, i. If one uses VRTs e. Support Center Support Center. There is another viewpoint concerning PHSP simulations of the manuxl treatment head, which should be considered.

With SBS, the value of NBRSPL is changed manua order to maximize the splitting of photons aimed into the field and to minimize unnecessary splitting of photons aimed away from the field. PIRS E The uncertainty was calculated in five different ways, i. Springer, Berlin,pp.

### BEAMnrc: software tool to model radiation beams – National Research Council Canada

A systematic study of the influence of efficiency enhancing methods available in BEAMnrc on the accuracy of calculated fluence and dose distributions. The boundary crossing algorithm together with the electron transport algorithm constitutes the condensed history technique used manua, a particular MC code system.

The tradeoff is that the no-VRT simulation is much slower, although if this simulation is being performed just once for subsequent use then it is a reasonable approach. In our study, ESAVE was set to 2 MeV in all component modules with the exception of the target where the electron cutoff energy value was used, as recommended in Sheikh—Bagheri et al. Data Tables 26 5—E The efficiency of BEAMnrc PHSP simulations is significantly improved, with directional bremsstrahlung splitting combined with augmented charged particle range rejection, for the two field sizes studied.

## BEAMnrc: software tool to model radiation beams

This efficiency gain is achieved through the use of variance reduction techniques and faster simulation of the electron transport. This mqnual essential if one is considering real-time MC simulation of the treatment head and patient. The current version of BEAMnrc allows the user to choose three different photon cross sections: Please review our privacy policy. VRTs do not change the physics and therefore do not bias the results.

Some of these special-purpose MC codes are being used as a dose engine for MC-based treatment planning in the routine clinical setting.

Augmented range rejection accounts correctly baemnrc 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. The results presented emphasize the importance of using a proper measure of the uncertainty on the quantity of interest in the calculation of the efficiency of a MC simulation.