SU-E-T-488: Dose Calculation Model Using the Simplified Monte Carlo Method with an Initial Beam Model Adapted to a Beam-Wobbling System

2012 ◽  
Vol 39 (6Part17) ◽  
pp. 3817-3817
Author(s):  
R Tansho ◽  
R Kohno ◽  
Y Takada ◽  
K Hotta ◽  
Y Hara ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Dose Calculation ◽  
Calculation Model ◽  
Beam Model ◽  
Initial Beam

Experimental verification of dose calculation using the simplified Monte Carlo method with an improved initial beam model for a beam-wobbling system

2013 ◽  
Vol 58 (17) ◽  
pp. 6047-6064 ◽  
Author(s):  
Ryohei Tansho ◽  
Yoshihisa Takada ◽  
Ryosuke Kohno ◽  
Kenji Hotta ◽  
Yousuke Hara ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Experimental Verification ◽  
Dose Calculation ◽  
Beam Model ◽  
Initial Beam

Monte Carlo calculations of an Elekta Precise SL-25 photon beam model

2015 ◽  
pp. 1-12
Author(s):  
Fátima Padilla-Cabal ◽  
Mailyn Pérez-Liva ◽  
Elier Lara ◽  
Rodolfo Alfonso ◽  
Neivy Lopez-Pino
Keyword(s):  
Monte Carlo ◽  
Measurement Data ◽  
Dose Calculation ◽  
Photon Beam ◽  
Beam Model ◽  
Dose Calculations ◽  
Clinical Implementation ◽  
Dose Distributions ◽  
Major Barrier ◽  
Reconstruction Methods

AbstractBackgroundMonte Carlo (MC) simulations have been used extensively for benchmarking photon dose calculations in modern radiotherapy using linear accelerators (linacs). Moreover, a major barrier to widespread clinical implementation of MC dose calculation is the difficulty in characterising the radiation source using data reported from manufacturers.PurposeThis work aims to develop a generalised full MC histogram source model of an Elekta Precise SL-25 linac (electron exit window, target, flattening filter, monitor chambers and collimators) for 6 MV photon beams used in standard therapies. The inclusion of many different probability processes such as scatter, nuclear reactions, decay, capture cross-sections and more led to more realistic dose calculations in treatment planning and quality assurance.Materials and methodsTwo different codes, MCNPX 2·6 and EGSr-BEAM, were used for the calculation of particle transport, first in the geometry of the internal/external accelerator source, and then followed by tracking the transport and energy deposition in phantom-equivalent tissues. A full phase space file was scored directly above the upper multilayer collimator’s jaws to derive the beam characteristics such as planar fluence, angular distribution and energy spectrum. To check the quality of the generated photon beam, its depth dose curves and cross-beam profiles were calculated and compared with measured data.ResultsIn-field dose distributions calculated using the accelerator models were tuned to match measurement data with preliminary calculations performed using the accelerator information provided by the manufacturer. Field sizes of 3×3, 5×5, 10×10, 15×15 and 20×20 cm2were analysed. Local differences between calculated and measured curve doses beneath 2% were obtained for all the studied field sizes. Higher discrepancies were obtained in the air–water interface, where measurements of dose distributions with the ionisation chamber need to be shifted for the effective point of measurement.ConclusionThe agreements between MC-calculated and measured dose distributions were excellent for both codes, showing the strength and stability of the proposed model. Beam reconstruction methods as direct input to dose-calculation codes using the recorded histograms can be implemented for more accurate patient dose estimation.

scholarly journals Implementation of a Compact Spot-Scanning Proton Therapy System in a GPU Monte Carlo Code to Support Clinical Routine

2020 ◽  
Vol 8 ◽  
Author(s):  
Jan Gajewski ◽  
Angelo Schiavi ◽  
Nils Krah ◽  
Gloria Vilches-Freixas ◽  
Antoni Rucinski ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Beam Model ◽  
Monte Carlo Code ◽  
Transverse Beam ◽  
Beam Shape ◽  
Clinical Criteria

The purpose of this work was to implement a fast Monte Carlo dose calculation tool, Fred, in the Maastro proton therapy center in Maastricht (Netherlands) to complement the clinical treatment planning system. Fred achieves high accuracy and computation speed by using physics models optimized for radiotherapy and extensive use of GPU technology for parallelization. We implemented the beam model of the Mevion S250i proton beam and validated it against data measured during commissioning and calculated with the clinical TPS. The beam exits the accelerator with a pristine energy of around 230 MeV and then travels through the dynamically extendable nozzle of the device. The nozzle contains the range modulation system and the multi-leaf collimator system named adaptive aperture. The latter trims the spots laterally over the 20 × 20 cm2 area at the isocenter plane. We use a single model to parameterize the longitudinal (energy and energy spread) and transverse (beam shape) phase space of the non-degraded beam in the default nozzle position. The range modulation plates and the adaptive aperture are simulated explicitly and moved in and out of the simulation geometry dynamically by Fred. Patient dose distributions recalculated with Fred were comparable with the TPS and met the clinical criteria. Calculation time was on the order of 10–15 min for typical patient cases, and future optimization of the simulation statistics is likely to improve this further. Already now, Fred is fast enough to be used as a tool for plan verification based on machine log files and daily (on-the-fly) dose recalculations in our facility.

scholarly journals The simulation of a linear accelerator using Monte Carlo method with EGSnrc Program

2019 ◽  
Vol 2 (4) ◽  
pp. 103-111
Author(s):  
Tai Thanh Duong ◽  
Tuan Duc Hoang ◽  
Oanh Thi Luong ◽  
Loan Thi Hong Truong ◽  
Son Dong Nguyen
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Excellent Agreement ◽  
Linear Accelerator ◽  
Evaluation Method ◽  
Dose Calculation ◽  
Calculation Algorithm ◽  
Simulation Accuracy ◽  
Depth Dose ◽  
Passing Rate

The Monte Carlo method is considered to be the most accurate algorithm for dose calculation in radiotherapy. Linear accelerator accurate simulation is required as a prior condition for Monte Carlo dose calculation algorithm. In this study, the 6 MV photon beams from a Siemens Primus Linear Accelerator (LINAC) M5497 at the Dong Nai General Hospital was modelled by using EGSnrc. The BEAMnrc và DOSXYZnrc user code were used for simulation the head of LINAC and the dose distribution in water phantom. The percentage depth dose (PDD) and beam profiles (OCR) were calculated and then compared with the measured ones in order to evaluate the simulation accuracy. Excellent agreement was found between simulations and measurements with an average difference of 1.26 % for PDD, less than 2 % for OCR. In addition, the gamma evaluation method for simulation was also performed using an in-house Matlab code. The percentage gamma passing rate was 100% for PDD and 98.5 % for OCR with 3 % dose difference and 3 mm distance to agreement as acceptance criteria. The result showed that we had successfully simulated LINAC with excellent agreement.

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