• 보존과학연구
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• s.26
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• pp.189-202
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• 2005

This study carried out to understand thermoluminescence dating of ancient tiles at Jinju Janghungri Kilin site. Also radiocarbon dating by the benzene synthesis method and Liquid scintillation counting method were performed for comparison for the agedetermination of charcoal sample at the obtained same site.1st and 2nd glow curve were obtained according to the typical method thermoluminescence. Plateau tests of revealed the proper temperature range to be $300~440^{\circ}C$ Palaeodose average values were formed to the 2.44Gy.Annual dose of ancient tiles was calculated from soil samples and ancient tiles it self by measuring alpha radiation dose, potassium concentrations and water contents respectively. Annual dose average values were calculated to be 7.012mGy/yr.The radiocarbon age(BP year) was converted to calibrated age(AD/BC year) using high precision curve. Radiocarbon ages were calculated to be AD 15~17 .Comparison of samples with their radiocarbon and thermoluminescence ages for revealed the in range the AD 15~17. This result means that the measured absolute ages are in good agreement with each other within the margin of error.

• 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.

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.160-167
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• 2011

This study conducts cross-comparison through verification of treatment planning of using beam spoiler and bolus, according to the dose variation of different tumor bed and metastatic lymph node cancers, against ionization and optically stimulated luminescence detectors(OSLDs), in head and neck radiotherapy. Verification of treatment planning examined the feasibility of inserting detectors through simulated solid dry water slabs under identical irradiated conditions from treatment planning system to measure beam spoiler and 0.5, 1 cm bolus. In addition, two detectors were cross-compared for verification of treatment planning accuracy and reliability within ${\pm}$2%. The study found that, given a beam spoiler thickness of 0.5 cm and beam spoiler-to-skin distance of 10 cm subjected to optimal dose distribution given for metastatic lymph node cancers, the bolus low-level skin dose was less, and the tumor bed dose reduced slightly. Additionally, two detectors were cross-compared for accuracy within ${\pm}$1%. Accordingly, The use of beam spoiler was determined that reduces skin side effects and can deliver an optimal dose distribution for tumor, and to apply to future clinical studies should be performed.

• Korean Journal of Head & Neck Oncology
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• v.7 no.1
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• pp.3-9
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• 1991

Brachytherapy is a method of radiotherapy in advantage to achieve better local control with minimum radiation toxicity in comparison with external irradiation because radiation dose is distributed according to the inverse square low of gamma-ray emitted from the implanted sources. The main characteristics of brachytherapy are delivering of higher dose to target volume shortening of total treatment period and sparing of normal tissue. Recent development of iridium ribbons for low dose rate implant provides improvement of technology of brachytherapy in terms of safety and efficiency. High dose rate method. on the other hand, is effective to avoid unnecessary expoure of medical personnel.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.189-195
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• 2017

Gel dosimeters have unique advantages in comparison with other dosimeters. Until now, these gels have been used in different radiotherapy techniques as a reliable dosimetric tool. Because dose distribution measurement is an important factor for appropriate treatment planning in different radiotherapy techniques, in this study, we evaluated the ability of the N-isopropylacrylamide (NIPAM) polymer gel to record the dose distribution resulting from the mixed neutron-gamma field of boron neutron capture therapy (BNCT). In this regard, a head phantom containing NIPAM gel was irradiated using the Tehran Research Reactor BNCT beam line, and then by a magnetic resonance scanner. Eventually, the $R_2$ maps were obtained in different slices of the phantom by analyzing T2-weighted images. The results show that NIPAM gel has a suitable potential for recording three-dimensional dose distribution in mixed neutron-gamma field dosimetry.

• Journal of Astronomy and Space Sciences
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• v.40 no.2
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• pp.59-66
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• 2023

Since the World Health Organization (WHO) officially announced a global pandemic on March 12, 2020, the aviation industry in the world has been experiencing difficulties for a long time. Meanwhile, the Ukraine war broke out in February, and from March 15, domestic airlines must operate air routes bypassing Russian airspace despite the longer flight time. Therefore, as the flight time increases, the cosmic radiation exposure dose of the crew members is also expected to increase. Here we compare the radiation exposure dose between the route doses for the eastern United States and Europe before and after the detour route usage. Through the comparison analysis, we tried to understand how cosmic radiation changes depending on the flight time and the latitude and which one contributes more. We expect that this study can be used for the policy update for the safety management of cosmic radiation for aircrews in Korea.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.233-239
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• 2016

Comparison of the dose aspect that radiation therapy treatments using IMRT, tomotherapy, mArc (modulated arc therapy). The experimental subject is non-small cell lung cancer patient. The prescription dose is 58.0 Gy to the volume of PTV(planning target volume). and spinal cord, esophagus, and liver organ is the normal organ(OAR, organ at risk). Average PTV value is 57.60 Gy in mArc and 61.04 Gy in tomotherapy and 58.95 Gy in IMRT. The average dose of the Esophagus is 2.84 Gy in m-Arc, 5.14 Gy in tomotherapy, 1.84 Gy in IMRT. The average dose of the Liver is 19.44 Gy in m-Arc, 12.22 Gy in tomotherapy, 21.97 Gy in IMRT. The average dose of the Spinal cord is 5.72 Gy in m-Arc, 7.08 Gy in tomotherapy, 6.15 Gy in IMRT. Results of this study is no significant difference between mArc and tomotherapy and Linac based IMRT in dose study and also, mArc's dose coverage and dose volume histogram is better than IMRT and tomotherapy. but, This study is limited to a disease of cancer. in addition, fewer number of groups. The wide range the more research can be developed patient-specific treatment techniques and be applied to the patients

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.65-70
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• 2012

Purpose : The aim of this study was to compare the effective dose for imaging of mandible between multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). An MDCT with low dose technique was also compared with them. Materials and Methods : Thermoluminescent dosimeter (TLD) chips were placed at 25 organ sites of an anthropomorphic phantom. The mandible of the phantom was exposed using 2 different types of MDCT units (Somatom Sensation 10 for standard-dose MDCT, Somatom Emotion 6 for low-dose MDCT) and 3 different CBCT units (AZ3000CT, Implagraphy, and Kavo 3D eXaM). The radiation absorbed dose was measured and the effective dose was calculated according to the ICRP 2007 report. Results : The effective dose was the highest for Somatom Sensation 10 (425.84 ${\mu}Sv$), followed by AZ3000CT (332.4 ${\mu}Sv$), Somatom Emotion 6 (199.38 ${\mu}Sv$), and 3D eXaM (111.6 ${\mu}Sv$); it was the lowest for Implagraphy (83.09 ${\mu}Sv$). The CBCT showed significant variation in dose level with different device. Conclusion : The effective doses of MDCTs were not significantly different from those of CBCTs for imaging of mandible. The effective dose of MDCT could be markedly decreased by using the low-dose technique.

• International Journal of Contents
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• v.7 no.4
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• pp.103-107
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• 2011

The effective dose and the organ absorbed dose, which are given to a breast in the cases of using and not using the bismuth breast protection shield for the protection of a breast with the coronary artery CT angiography, have been measured and compared for the manual exposure control (MEC)and the automatic exposure control (AEC). In the cases of using and not using the bismuth breast protection shield, it has been found that the measured dose shows the reduction of about 23 to 26% for the MEC and about 22 to 25% for the AEC when the shield is used compared to the case of not using it. By comparing the shield and non-shield cases for the AEC and the MEC, it can be said that the value measured by carrying out the scanning process with the AEC mode has decreased by about 24 to 30% compared to the case of applying the MEC mode. Such a result shows that it is recommended to use the AEC mode for the reduction of the patient's exposure dose during the CT examination.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.603-610
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• 2018

This study examined the following: accuracy of the exposure conditions in the inverter device and three-phase device; output waveform over the exposure conditions; and average and standard deviation of the output waveform. After assessing whether the dose corresponding to the theoretical dose was presented, the following conclusions were obtained: 1. The accuracy of the tube voltage(kVp) and tube current(mA) exposure time(sec) was within the tolerable level prescribed in Korea's Safety Management Standards. In the error, Inverter device was large the tube voltage and exposure time, the three-phase device was large the tube current. 2. In terms of the output waveform of the exposure conditions and the average and standard deviation of the output waveform, the higher tube voltage and larger tube current resulted in greater standard deviation in pulsation. Moreover, the standard deviation of pulsation was shown to be greater in the inverter device than the three-phase device; there was also greater standard deviation in the inverter device considering the exposure time. 3. Regarding the exposure conditions over the output dose, all linearity showed the coefficient of variation which had an allowable limit of error within 0.05. Although the output dose ratio for the inverter device was 1.00~1.10 times no difference that of the three-phase device, there was almost no difference in dose ratio between the tube currents.