• 대한방사선방어학회:학술대회논문집
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• 2009.11a
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• pp.114-115
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• 2009

• Progress in Medical Physics
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• v.9 no.3
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• pp.175-184
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• 1998

The dose distribution evaluation program for the stereotactic radiosurgery treatment planning system using a gamma knife has been built in order to work on PC. And this custom-made dose distribution is compared with that of commercial treatment planning program. 201 source position of a radiation unit were determined manually using a gamma knife collimator draft and geometrical coordinates. Dose evaluation algorithm was modified for our purpose from the original KULA, a commercial treatment planning program. With the composed program, dose distribution at the center of a spherical phantom, 80 mm in diameter, was evaluated into axial, coronal and sagittal image per each collimator. Along with this evaluated data, the dose distribution at a arbitrary point of inside the phantom was compared with those from KULA. Radiochromic film was set up at the center of the phantom and was irradiated by gamma knife, for the verification of dose distribution. In result, the deviation of the dose distribution from that of KULA is less than ${\pm}$3%, which is equivalent to ${\pm}$0.3 mm in 50% isodose distribution for all examined coordinates and film verification. The custom-made program, GPl is proven to be a good tool for the stereotactic radiosurgery treatment planning program.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2005.04a
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• pp.42-46
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• 2005

The Dose calculation program for the Buchler remote after-loading system was developed. We use iridium source for the tandem and cessium for the ovoids. We determined the source length and distributions by dividing the program disk to 72 points. The dose rate for the each program disk were calculated and stored to the tables for the xy coordinates. The dose rate for the interesting points for the patients were calculated by using these tables. We also made isodose curve from the calculations. By using the program, we could calculate the dose rate for the various points of the patient quickly and accurately.

• Radiation Oncology Journal
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• v.14 no.3
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• pp.247-253
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• 1996

Purpose : The dose calculation program for the Buckler type remote after-loading system was developed. This program also can be used to calculate dose for various sealed sources. Materials and Methods : We determined the source length and distribution by dividing the program disk to 72 points. The dose rate for the each program disk and source was calculated. The dose rate table for the xy coordinate was established. The dose rate for the interesting points of the patient were calculated by using this table, We also made isodose curve from this calculations. Results : The storage size for the dose rate table were increased. But the calculation of the dose rate for the patient were carried out rapidly. So we could get real time calculation. Conclusion : By using this program, we could calculate the dose rate for the various points of the patient quickly and accurately. This program will be useful for the treatment with various linear sources.

• Progress in Medical Physics
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• v.25 no.1
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• pp.23-30
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• 2014

The purpose of this study is to evaluate the developed dose verification program for in vivo dosimetry based on transit dose in radiotherapy. Five intensity modulated radiotherapy (IMRT) plans of lung cancer patients were used in the irradiation of a homogeneous solid water phantom and anthropomorphic phantom. Transit dose distribution was measured using electronic portal imaging device (EPID) and used for the calculation of in vivo dose in patient. The average passing rate compared with treatment planning system based on a gamma index with a 3% dose and a 3 mm distance-to-dose agreement tolerance limit was 95% for the in vivo dose with the homogeneous phantom, but was reduced to 81.8% for the in vivo dose with the anthropomorphic phantom. This feasibility study suggested that transit dose-based in vivo dosimetry can provide information about the actual dose delivery to patients in the treatment room.

• Korean Journal of Environmental Biology
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• v.24 no.4
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• pp.387-391
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• 2006

Computational and experimental dosimetry of Henschke applicator with respect to high dose rate brachytherapy using the MIRD phantom and a remote control afterloader were performed. A comparison of computational dosimetry was made between the simulated Monte Carlo dosimetry and GAMMADOT brachytherapy Planning system's dosimetry. Dose measurements was performed using ion chamber in a water phantom. Dose rates are calculated using Monte Carlo code MCNP4B and the GAMMADOT. Thecomputational models include the detailed geometry of Ir-192 source, tandem tube, and shielded ovoids for accurate estimation. And transit dose delivered during source extension to and retraction from a given dwell position was estimated by Monte Carlo simulations. Point doses at ICRU bladder/rectal pointswhich have been recommened by ICRU 38 was assessed. Calculated and measured dose distribution data agreed within 4% each other. The shielding effect of ovoids leads to 19% and 20% dose reduction at bladder surface and rectal points.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.248-249
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• 2009

• 대한방사선방어학회:학술대회논문집
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• 2010.04a
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• pp.64-65
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• 2010

• Progress in Medical Physics
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• v.11 no.2
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• pp.91-99
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• 2000

This is a preliminary study for developing the method of the dose reconstruction in the patients, irradiated by mega-voltage photon beams from the linear accelerator, using the transit dose distributions. In this study we present the method of three-dimensional dose reconstruction and evaluate the method by computer simulation. To acquire the dose distributions in the patients (or phantoms) we first calculate the differences between the doses at the arbitrary points in the patients and the doses at the corresponding points where the transit doses are measured. Then, we can get the dose in the patients from the measured transit dose and the calculated value of the difference. The dose differences are calculated by applying the inverse square law and using the linear attenuation coefficient. The scatter to primary dose ratios, which are calculated by the Monte Carlo program using the CT data of the patient (or phantoms), are also used in the calculations. For the evaluation of this method we used various kinds of homogeneous and inhomogeneous phantoms and calculated the transit dose distributions with the Monte Carlo program. From the distributions we reconstructed the dose distributions in the phantom. We used mono-energy Photon beam of 1.5MeV and Monte Carlo program EGS4. The comparison between the dose distributions reconstructed using the method and the distributions calculated by the Monte Carlo program was done. They agreed within errors of -4%∼+2%. This method can be used to predict the dose distributions in the patient

• Progress in Medical Physics
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• v.16 no.3
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• pp.130-137
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• 2005

In total body irradiation (T81) for leukemia, we have a two methode. One is a AP (anterior-posterior) method and the other is a Lateral methode. Our hospital used lateral methode. T81 must consider about body contour, because of homogeneous dose distribution. For compensation about irregular body contour, we use compensator. For T81 treatment, we must be considered, accurate manufacture of compensator and accurate calculation of dose. We developed the automatic program for T81. This program accomplished for compensator design and dose calculation for irregular body. This program was developed for uses to use in a windows environment using the IDL language. In this program, it use energy data for each energy: TMR, output factor, inverse square law, spoiler, field size factor. This program reduces the error to happen due to the manual. As a development of program, we could decrease the time of treatment plan and care the patient accurately.