• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.285-291
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• 2013

In this study, compare and analyze the dose distribution and availability of radiation therapy when using a different devices to TNI(Total Lymphnodal Irradiation). Test subjects(patients) are 15 people(Male 7, Female 8). Acquire CT Simulation images of the 15 people using Somatom Sansation Open 16 channel and then acquired images was transferred to each treatment planning system Pinnacle Ver 8.0 and Tomotherapy Planning System and separate the tumor tissue and normal tissues(whole lung, spinal cord, Rt kidney, Lt kidney). Tumor prescription dose was set to 750 cGy. and then Compare the Dose Compatibility, Normal Tissue's Absorbed Dose, Dose Distribution and DVH. Statistical analysis was performed SPSS Ver. 18.0 by paired sample Assay. The absorbed dose in the tumor tissue was $751.0{\pm}4.7cGy$ in tomotherapy planning, $746.9{\pm}14.1cGy$ in linac. Tomotherapy's absorbed dose in the tumor was more appropriate than linac. and These values are not statistically significant(p>0.05). Tomotherapy plan's absorbed dose in the normal tissues were less than linac's plan. This value was statistically significant(p<0.05) excepted of whole lung. In DVH, appropriated on tumor and normal tissues in tomotherapy and linac but tomotherapy's TER was better than linac. Namely, a result of Absorbed dose in tumor and normal tissue, Dose distribution pattern, DVH, Both radiation therapy devices were appropriated in radiation therapy on TER. The Linac has a short treatment time(about 15-20 min) and open space on treatment time. It cause infant and pediatric patients to receiving uncomfortable treatment. So, In this case, it will be fine that Linac based therapy was restricted use. and if the patient was cooperative, it will be show a better prognosis that Tomotherapy using Radiation Therapy.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.495-500
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• 2004

The neutron capture cross section of $^{99}Tc$ has been measured relative to the $^{10}B$(n,g) standard cross section by the neutron time-of-flight(TOF) method in the energy range of 0.007 eV to 47keV using a 46-MeV electron linear accelerator(linac) at the Research Reactor Institute, Kyoto University(KURRI). In order to experimentally prove the result obtained, the supplementary cross section measurement has been made from 0.3 eV to 1 keV using the Kyoto University Lead slowing-down Spectrometer(KULS) coupling to the linac. The relative measurement by the TOF method has been normalized to the reference value(20.01 b) at 0.0253 eV and the KULS measurement to that by the TOF method. The existing experimental data and the evaluated capture cross sections in ENDF/B-VI, JENDL-3.2, and JEF-2.2 have been compared with the current measurements by the linac TOF and the KULS experiments. The energy dependency of the KULS data is close to that of the TOF data which are energy-broadened by the resolution function of the KULS.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7811-7816
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• 2014

Background: Despite advances in radiotherapy, overall survival of glioblastoma multiforme (GBM) patients is still poor. Moreover dosimetrical analyses with these newer treatment methods are insufficient. The current study is aimed to compare intensity modulated radiation therapy (IMRT) linear accelerator (linac) and helical tomotherapy (HT) treatment plans for patients with prognostic aggressive brain tumors. Material and Methods: A total of 20 GBM patient plans were prospectively evaluated in both linac and HT planning systems. Plans are compared with respect to homogenity index, conformity index and organs at risk (OAR) sparing effects of the treatments. Results: Both treatment plans provided good results that can be applied to GBM patients but it was concluded that if the critical organs with relatively lower dose constraints are closer to the target region, HT for radiotherapeutical application could be preferred. Conclusion: Tomotherapy plans were superior to linear accelerator plans from the aspect of OAR sparing with slightly broader low dose ranges over the healthy tissues. In case a clinic has both of these IMRT systems, employment of HT is recommended based on the observed results and future re-irradiation strategies must be considered.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.198-200
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• 2005

The 2.5 GeV linac of the Pohang Light Source(PLS) is planed to be converted to a XFEL. The PAL XFEL requires a new 1.2-GeV linac that will be combined to the existing linac to increase a beam energy upto 3.7 GeV. The RF stability of 0.02 % is required for both RF phase and amplitude to get the XFEL output. This stability is mainly determined by a low level RF drive system and klystron-modulators. The stability level of the modulator has to be improved 10 times better to meet the pulse stability of 0.02 %. The regulation methods such as traditional de-Qing and precision inverter charging technology are reviewed to find out suitable upgrade scheme of the modulators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1035-1039
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• 2010

Activation products generated by photoneutrons in concrete shielding wall around electron linac were estimated for a high energy X-ray container cargo inspection system. Monte carlo code, MCNPX2.5.0 was used for reference system of 9MeV fixed type dual-direction container cargo inspection system installed at major harbors in Korea. Activation products inventory generated by photoneutron (n,$\gamma$) reaction are estimated, and then radiation dose rate is calculated from the results.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.753-761
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• 2024

Introduction: In this study, TLD 600 and TLD 700 pairs were used to measure the neutron dose of Elekta Precise medical linac. To this end, the optimum moderate thickness for the conversion of fast to thermal neutrons were evaluated. Materials and methods: ²⁴¹Am-Be and ²⁵²Cf sources were simulated to calculate the optimum thicknesses of the moderator for the conversion of maximum fast neutrons (FN) into thermal neutrons (TN). Pair TLDs were used to measure F&TN doses for three different field sizes at four depths of the medical linac. Results: The maximum thickness of the moderator was optimized at 6 cm. The measurement results demonstrated that the TN dose increased with the expansion of field size and depth. The FN dose, which was converted TN, exhibits behaviors comparable to the TN due to its nature. Conclusion: This study presents the optimum thickness for the moderator to convert FN into TN and measure F&TN using TLDs.

• Progress in Medical Physics
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• v.22 no.4
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• pp.178-183
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• 2011

The applicability and feasibility of TomoTherapy in the lung radiation surgery was analyzed by comparison of the calculated dose distribution in TomoTherapy planning with the results of conventional IMRS (intensity modulated radiation surgery) using LINAC (linear accelerator). The acquired CT (computed tomograph) images of total 10 patients whose tumors' motion were less than 5 mm were used in the radiation surgery planning and the same prescribed dose and the same dose constraints were used between TomoTherapy and LINAC. The results of TomoTherapy planning fulfilled the dose requirement in GTV (gross tumor volume) and OAR (organ at risk) in the same with the conventional IMRS using LINAC. TomoTherapy was superior in the view point of low dose in the normal lung tissue and conventional LINAC was superior in the dose homogeneity in GTV. The calculated time for treatment beam delivery was long more than two times in TomoTherapy compared with the conventional LINAC. Based on the results in this study, TomoTherapy can be evaluated as an effective way of lung radiation surgery for the patients whose tumor motion is little when the optimal planning is produced considering patient's condition and suitability of dose distribution.

• The Journal of Korean Society for Radiation Therapy
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• v.5 no.1
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• pp.83-87
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• 1992

• The Journal of Korean Society for Radiation Therapy
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• v.8 no.1
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• pp.103-107
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• 1996

• The Journal of Korean Society for Radiation Therapy
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• v.8 no.1
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• pp.131-133
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• 1996