• Progress in Medical Physics
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• v.1 no.1
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• pp.75-84
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• 1990

We have claculated the absorbed dose distributions in water phantom irradiated by high energy photon beam. PDD (Percent Depth Dose) and Beam Profile can be represented by functions of depths and distances by using one dimensional model model based on transport theory. The parameters on scattering and absorption are evaluated by using non-linear regression process method. The values neeessary for calculation are obtained by simple experiment. The calculated values are in good agreement with the measured values.

• 수도
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• v.23 no.6 s.81
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• pp.22-29
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• 1996

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.200-201
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.333-333
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• 1998

• The Journal of Korean Society for Radiation Therapy
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• v.4 no.1
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• pp.12-16
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• 1990

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
• /
• pp.325.1-325
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• 1999

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.05a
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• pp.93-94
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• 2011

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.397-398
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• 2017

• Progress in Medical Physics
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• v.16 no.3
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• pp.138-147
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• 2005

The Monte Carlo method cannot have been used for routine treatment planning because of heavy time consumption for the acceptable accuracy. Since calculation time is proportional to particle histories, we can save time by decreasing the number of histories. However, a small number of histories can cause serious uncertainties. In this study, we proposed Monte Carlo dose computation time and uncertainty reduction method using specially designed filters and adaptive denoising process. Proposed algorithm was applied to 6 MV photon and 21 MeV electron dose calculations in homogeneous and heterogeneous phantoms. Filtering time was negligible comparing to Monte Carlo simulation time. The accuracy was improved dramatically in all situations and the simulation of 1 $\%$ to 10$\%$ number of histories of benchmark in photon and electron dose calculation showed the most beneficial result. The empirical reduction of necessary histories was about a factor of ten to fifty from the result.

• Progress in Medical Physics
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• v.26 no.1
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• pp.36-41
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• 2015

The Monte Carlo based dose calculation program for stereotactic body radiotherapy was developed in this study. The Geant4 toolkit widely used in the radiotherapy was used for this study. The photon energy spectrum of the medical linac studied in the previous research was applied for the patient dose calculations. The geometry of the radiation fields defined by multi-leaf collimators were taken into account in the PrimaryGeneratorAction class of the Geant4 code. The total of 8 fields were demonstrated in the patient dose calculations, where rotation matrix as a function of gantry angle was used for the determination of the source positions. The DicomHandler class converted the binary file format of the DICOM data containing the matrix number, pixel size, endian type, HU number, bit size, padding value and high bits order to the ASCII file format. The patient phantom was constructed using the converted ASCII file. The EGSnrc code was used to compare the calculation efficiency of the material data.