Method for calculation the absolute dose in the Monte Carlo simulation

In this study, we presented the method for calculation the absolute dose in the Monte Carlo simulation following the prescription of Popescu et al for the 6 MV photon energy. The BEAMnrc was used to simulate 6 MV photon beams from a Siemens Primus M5497 linear accelerator at DongNai general hospital. The DOSXYZnrc was then used to calculate the dose distribution in a homogeneous phantom (in form of CT images). The absolute dose obtained from the MC and TPS were compared with measured ones using an ion chamber (Farmer Type Chamber FC65-P, IBA). The average doses discrepancy between the simulated and measured dose was 0.53±0.37% and between the simulated and TPS was 1.00±0.51%. Results showed good agreement between simulated, measured and calculated dosed on a homogeneous phantom.

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Application of Monte-Carlo Code to dose distribution calculation in a case of lung cancer by the emitted photon beams from Linear Accelerator

Nuclear Science and Technology ◽

10.53747/jnst.v5i4.205 ◽

2015 ◽

Vol 5 (4) ◽

pp. 39-44

Author(s):

Thanh Xuan Le ◽

Cam Thu Nguyen Thi ◽

Van Nghia Tran ◽

Hong Loan Truong Thi ◽

Thanh Nhon Vo

Keyword(s):

Lung Cancer ◽

Monte Carlo ◽

General Hospital ◽

Treatment Planning ◽

Dose Distribution ◽

Linear Accelerator ◽

Treatment Plan ◽

Monte Carlo Code ◽

Photon Beams ◽

Distribution Calculation

The dose distribution calculation is one of the major steps in radiotherapy. In this paper the Monte Carlo code MCNP5 has been applied for simulation 15MV photon beams emitted from linear accelerator in a case of lung cancer of the General Hospital of Kien Giang. The settings for beam directions, field sizes and isocenter position used in MCNP5 must be the same as those in treatment plan at the hospital to ensure the results from MCNP5 are accurate. We also built a program CODIM by using MATLAB® programming software. This program was used to construct patient model from lung CT images obtained from cancer treatment cases at the General Hospital of Kien Giang and then MCNP5 code was used to simulate the delivered dose in the patient. The results from MCNP5 show that there is a difference of 5% in comparison with Prowess Panther program – a semi-empirical simulation program which is being used for treatment planning in the General Hospital of Kien Giang. The success of the work will help the planners to verify the patient dose distribution calculated from the treatment planning program being used at the hospital.

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The effect of SSD, Field size, Energy and Detector type for Relative Output Factor measurement in small photon beams as compared with Monte Carlo simulation

Polish Journal of Medical Physics and Engineering ◽

10.2478/pjmpe-2019-0014 ◽

2019 ◽

Vol 25 (2) ◽

pp. 101-110

Author(s):

Itumeleng Setilo ◽

Oluwaseyi Michael Oderinde ◽

Freek Cp du Plessis

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Field Size ◽

Photon Beams ◽

Output Measurement ◽

Voxel Size ◽

Output Factor ◽

Ion Chamber ◽

Small Fields ◽

Mc Simulation

Abstract Introduction: Small fields photon dosimetry is associated with many problems. Using the right detector for measurement plays a fundamental role. This study investigated the measurement of relative output for small photon fields with different detectors. It was investigated for three-photon beam energies at SSDs of 90, 95, 100 and 110 cm. As a benchmark, the Monte Carlo simulation was done to calculate the relative output of these small photon beams for the dose in water. Materials and Methods: 6, 10 and 15 MV beams were delivered from a Synergy LINAC equipped with an Agility 160 multileaf collimator (MLC). A CC01 ion chamber, EFD-3G diode, PTW60019 microdiamond, EBT2 radiochromic film, and EDR2 radiographic film were used to measure the relative output of the linac. Measurements were taken in water for the CC01 ion chamber, EFD-3G diode, and the PTW60019. Films were measured in water equivalent RW3 phantom slabs. Measurements were made for 1 × 1, 2 × 2, 3 × 3, 4 × 4, 5 × 5 and a reference field of 10 × 10 cm2. Field sizes were defined at 100cm SSD. Relative output factors were also compared with Monte Carlo (MC) simulation of the LINAC and a water phantom model. The influence of voxel size was also investigated for relative output measurement. Results and Discussion: The relative output factor (ROF) increased with energy for all fields large enough to have lateral electronic equilibrium (LEE). This relation broke down as the field sizes decreased due to the onset of lateral electronic disequilibrium (LED). The high-density detector, PTW60019 gave the highest ROF for the different energies, with the less dense CC01 giving the lowest ROFs. Conclusion: These are results compared to MC simulation, higher density detectors give higher ROF values. Relative to water, the ROF measured with the air-chamber remained virtually unchanged. The ROFs, as measured in this study showed little variation due to increased SSDs. The effect of voxel size for the Monte Carlo calculations in water does not lead to significant ROF variation over the small fields studied.

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Monte Carlo simulation approaches to dose distributions for 6MV photon beams in clinical linear accelerator

Journal of Applied Biomedicine ◽

10.1016/j.bbe.2014.01.002 ◽

2014 ◽

Vol 34 (2) ◽

pp. 90-100 ◽

Cited By ~ 4

Author(s):

Ahmet Tartar

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Linear Accelerator ◽

Photon Beams ◽

Dose Distributions

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Grid Monte Carlo Simulation of a Medical Linear Accelerator

European Journal of Engineering Research and Science ◽

10.24018/ejers.2018.3.12.1001 ◽

2018 ◽

Vol 3 (12) ◽

pp. 40-43 ◽

Cited By ~ 1

Author(s):

Didi Samir ◽

Mustapha Zerfaoui ◽

Abdelilah Moussa ◽

Yassine Benkhouya ◽

Mehdi El Ouartiti

Keyword(s):

Monte Carlo ◽

Linear Accelerator ◽

Field Size ◽

Dose Profile ◽

Depth Dose ◽

Grid Simulation ◽

Medical Linear Accelerator ◽

Measured Dose ◽

Better Than ◽

Good Agreement

A full grid simulation of the head of an Elekta Synergy Platform medical linear accelerator is performed using the Geant4 Monte Carlo platform. The simulation includes all components of the accelerator head and a homogeneous water phantom. Results in terms of depth doses and lateral dose profiles are presented for 6 MV photon beam with the 10x10 cm2 reference field size at 100 cm distance from the source. Overall, a good agreement with the measured dose data is achieved with a precision better than 0.93% and 2.63% for the depth dose profile and lateral dose profiles respectively.

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The comparison between 6 MV Primus LINAC simulation output using EGSnrc and commissioning data

Journal of Radiotherapy in Practice ◽

10.1017/s1460396917000747 ◽

2018 ◽

Vol 17 (3) ◽

pp. 302-308 ◽

Cited By ~ 1

Author(s):

Mohammad Davoudi ◽

Ali Shabestani Monfared ◽

Mohammad Rahgoshay

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Dose Distribution ◽

Monte Carlo Model ◽

Dose Calculation ◽

Accurate Method ◽

Beam Profile ◽

Average Value ◽

Simulation Output ◽

Good Agreement

AbstractIntroductionMonte Carlo calculation method is considered to be the most accurate method for dose calculation in radiotherapy. The purpose of this research is comparison between 6 MV Primus LINAC simulation output with commissioning data using EGSnrc and build a Monte Carlo geometry of 6 MV Primus LINAC as realistically as possible. The BEAMnrc and DOSXYZnrc (EGSnrc package) Monte Carlo model of the LINAC head was used as a benchmark.MethodsIn the first part, the BEAMnrc was used for the designing of the LINAC treatment head. In the second part, dose calculation and for the design of 3D dose file were produced by DOSXYZnrc. The simulated PDD and beam profile obtained were compared with that calculated using commissioning data. Good agreement was found between calculated PDD (1·1%) and beam profile using Monte Carlo simulation and commissioning data. After validation, TPR20,10, TMR and Spvalues were calculated in five different field.ResultsGood agreement was found between calculated values by using Monte Carlo simulation and commissioning data. Average differences for five field sizes in this approach is about 0·83% for Sp. for TPR20,10differences for field sizes 10×10 cm2is 0·29% and for TMR in five field sizes, the average value is ~1·6%.ConclusionIn conclusion, the BEAMnrc and DOSXYZnrc codes package have very good accuracy in calculating dose distribution for 6 MV photon beam and it can be considered as a promising method for patient dose calculations and also the Monte Carlo model of primus linear accelerator built in this study can be used as method to calculate the dose distribution for cancer patients.

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