• Progress in Medical Physics
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• v.19 no.3
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• pp.172-177
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• 2008

As a part of estimating quantitative radiation treatment doses, we produced a mathematical phantom based on the standard Korean male. Then, with the prostate as the source organ, we calculated the absorbed dose in the prostate and surrounding organs forecasted to occur during brachytherapy for prostate cancer. To simulate the procedure, we selected $^{25}I$ and $^{103}Pd$ useful in brachytherapy of the prostate as the radionucleids and made an assumption that 1 Ci of initial radioactivity is administered. As a result, we found that the prostate, as the source organ, indicated 101 Gy/Ci and 7.24 Gy/Ci, respectively, in case of $^{125}I$ and $^{103}Pd$. With the exception of the prostate, organs with high absorbed doses were found to be in the order of the penis and scrotum, sigmoid colon, testicles and the urinary bladder, which are relatively close to the prostate.

• Progress in Medical Physics
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• v.17 no.4
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• pp.207-211
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• 2006

The advent of kV cone-beam computed tomography (CBCT) integrated with a linear accelerator allows for more accurate Image-guided radiotherapy (IGRT). IGRT is the technique that corrects target displacement based on internal body information. To do this, the CBCT Image set is acquired just before the beam is delivered and registered with the simulation CT Image set. In this study, we compare the registration results according to the CBCT's reconstruction quality (either high or medium). A total of 56 CBCT projection data from 6 patients were analyzed. The translation vector differences were within 1 mm in all but 3 cases. For rotation displacement difference, components of all three axes were considered and 3 out of 168 ($56{\times}3$ axes) cases showed more than lo of rotation differences.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.115-120
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• 2011

Purpose: To examine the feasibility of the treatment planning for minimizing carotid artery dose in the radiotherapy of early glottic cancer. Materials and Methods: From 2007 to 2010, computed tomography simulation images of 31 patients treated by radiotherapy for early glottic cancer were analyzed. The virtual planning was used to compare the parallel-opposing fields (POF) with the modified oblique fields (MOF) placed at angles to exclude the ipsilateral carotid arteries. Planning target volume (PTV), irradiated volume, carotid artery, and spinal cord were analyzed at a mean dose, $V_{35}$, $V_{40}$, $V_{50}$ and with a percent dose-volume. Results: The beam angles were arranged 25 degrees anteriorly in 23 patients and 30 degrees anteriorly in 8 dose-volume of carotid artery shows the significant difference (p<0.001). The mean doses of carotid artery were 38.5 Gy for POF and 26.3 Gy for MOF and the difference was statistically significant (p=0.012). Similarly, $V_{35}$, $V_{40}$, and $V_{50}$ also showed significant differences between POF and MOF. Conclusion: The modified oblique field was respected to prevent a carotid artery stenosis and reduce the incidence of a stroke based on these results.

• The Journal of Korean Society for Radiation Therapy
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• v.14 no.1
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• pp.85-88
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• 2002

I. 목적 : arm-up holder는 흉부 및 복부 질환 치료의 환자고정에 유용하게 사용하고 있으나 손잡이 부분과 어깨가 닿는 부분까지 거리 때문에 동일한 자세를 유지하는데 불편함이 있다. 특히 긴장을 많이 하거나 기력이 없는 환자는 방사선 치료 시 자세의 불안정으로 인하여 치료의 정확성이 떨어질 수 있다. 이에 본원에서는 현재 사용하고 있는 arm-up holder에 팔의 지지를 위한 보조기구를 제작하여 유용성을 평가하였다. II. 대상 및 방법 : 기존의 arm-up holder에 어깨받침대를 부착하여 개선된 arm-up holder를 제작하였다. 실험을 위하여 기존의 arm-up holder를 사용하는 환자그룹과 개선된 arm-up holder를 사용하는 그룹으로 구분하여 자세 변화를 평가하였다. 두 그룹의 환자를 대상으로 모의 치료를 실시한 후 치료실에서 L-gram 을 2회 씩 촬영하여 치료하고자 하는 portal film과 isocenter의 변화를 측정했다. 각 그룹 당 10명씩의 환자를 선정하여 반복 조사하였다. III. 결과 : 개선된 arm-up holder를 사용한 그룹의 isocenter 의 변화는 최대 2mm, 최소 0.5mm 평균 1.2mm 이다. 기존의 arm-up folder를 사용한 그룹과 비교하여 평균변화는 약 2배로 나라났고, 최대 변화는 2.5배의 오차범위가 측정되었다. IV. 결론 : 현재 사용하고 있는 arm-up holder는 흉부 및 복부의 사방향 방사선 치료 시 팔에 의한 방사선 감약을 예방할 수 있는 유용한 고정용구이다. 하지만 팔을 올리고 있는 자세는 환자에게 불편함을 야기 시키며 이로 인한 치료의 정확성을 감소시킬 수 있다. 따라서, 기존의 arm-up holder에 보조기구를 제작하여 사용함으로써 환자의 불편함을 개선하고, set-up 의 안정성과 재현성을 향상시킬 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.655-662
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• 2010

By using lotus notes server-client system, the database related to general information of cancer patients, radiation treatment simulation, cancer treatment information and all kinds of information of radiation oncology department need to be developed for effective information management and also user interface was developed for input and output of information. This database also could be used for clinical study, patient care research and medical education. By the development of this electronic chart of the department of radiation oncology, the clinic datum and medical information management could be connected effectively and treatment information according to treatment machine also could be acquired and contributed for improving treatment efficiency, cutting down the waiting time for clinic.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.172-178
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• 1999

Purpose : To measure the basic structural characteristics of radiation oncology facilities in Korea during 1997 and to compare personnel, equipments and patient loads between Korea and developed countries. Methods and Materials : Mail serveys we conducted in 1998 and data on treatment machines, personnel and peformed new patients were collected. Responses were obtained from the 100 percent of facilities. The consensus data of the whole country were summarized using Microsoft Excel program. Results: In Korea during 1997, 42 facilities delivered megavoltage radiation theraphy with 71 treatment machines, 100 radiation oncologists, 26 medical physicist, 205 technologists and 19,773 new patients. Eighty nine percent of facilities in Korea had linear accelators at least 6 MeV maximum photon energy. Ninety five percent of facilities had simulators while five percent of facilities had no simulator, Ninety one percent of facilities had computer planning systems and eighty three percent of facilities reported that they had a written quality assurance program. Thirty six percent of facilities had only one radiation oncologist and thirty eight percent of facilities had no medical physicists. The median of the distribution of annual patients load of a facility, patients load per a machine, patients load per a radiation oncologist, patients load per a therapist and therapists per a machine in Korea were 348 patients per a year, 263 patients per a machine, 171 patients per a radiation oncologist, 81 patients per a therapist, and 3 therapists per a machine respectively. Conclusions : The whole scale of the radiation oncology departments in Korea was smaller than Japan and USA in population ratio regard. In case of hardware level like linear accelerators, simulators and computer planning systems, there was no big differences between Korea and USA. The patients loads of radiation oncologists and therapists had no significant differences as compared with USA. However, it was desirable to consider the part time system in USA because there were a lot of hospitals which did not employ medical physicists.

• Progress in Medical Physics
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• v.15 no.3
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• pp.134-139
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• 2004

This study was aimed to develop a new ovoid applicator for vaginal high-dose rate intracavitary radiation therapy, evaluate uniformity of dose distribution, and assess clinical applicability. The authors evaluated dose uniformity of vaginal mucosa according to 5-different ovoid-separation using 2-channel and modified 3-channel ovoid applicator. There were no significant differences in the dose distribution along the vaginal mucosa with 2 and 2.5 cm separations, but there were between the 2-channel and 3-channel ovoid applicator with a separation of 3 cm or more. Although a low dose area was shown between two ovoid applicators with the 2-channel ovoid applicator, the dose distribution along the vaginal mucosa with the 3-channel ovoid applicator was very uniform.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.254-261
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• 2009

This study suggested that the table of CT-simulator and the laser alignment system using diagnostic CT scanner have an efficient method for improvement in alignment between the planned target center of traverse image with CT scanner. It was conducted on the daily QA when presented in the AAPM TG66 with correcting the laser alignment system using geometric trigonometric functions and investigated the effectiveness of correction methods as compared with those before and after correction. Before correction error was 3.82mm between the planned target center of image, the table longitudinal axis was twisted with 0.436o. The laser alignment system using geometric trigonometric functions in after correction was satisfied with tolerance limits of ${\pm}2mm$ when occurred about 0.7mm in errors between the planned target center. The table correction to satisfy the geometric accuracy is very inefficient over against the time and economic loss as well as technical limits in the case of application as only radiation therapy associated with CT-simulator with diagnostic CT scanner in use. But, the method which corrects the laser alignment system is economic and relatively simple with possibility of getting well geometric accuracy and we suppose that it is efficient method for applying in the clinic.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.641-649
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• 2023

This study compares and analyzes the performance of a shield manufactured using 3D printing technology to find out its applicability as a shield in high-energy electron beam therapy. Actual measurement and monte carlo simulations were performed to evaluate the shielding performance of 3D printing materials for high-energy electron beams. First, in order to secure reliability for the simulation, a source term evaluation was conducted by referring to the IAEA's TRS-398 recommendation. Second, to analyze the shielding performance of PLA+W (93%), a specimen was manufactured using a 3D printer, and the shielding rate by thickness according to electron beam energy was evaluated. Third, the shielding thickness required for electron beam treatment was calculated through a comparative analysis of shielding performance between PLA+W (93%) and existing shielding bodies. First, as a result of the evaluation of the source term through actual measurement and simulation, the TRS-398 recommendation was satisfied with an error of less than 1%, thereby securing the reliability of the simulation. Second, as a result of the shielding performance analysis for PLA+W (93%), 6 MeV electron beams showed a shielding rate of more than 95% at 3.12 mm, and 15 MeV electron beams showed a shielding rate of more than 90% at 10 mm thickness. Third, through simulations, comparative analysis between PLA+W (93%) materials and existing shields showed high shielding rates within the same thickness in the order of tungsten, lead, copper, PLA+W (93%), and aluminum. 6 MeV electron beams showed almost similar shielding rates at 5 mm or more and 15 MeV electron beams. Through this study in the future, it is judged that it can be used as basic data for the production and application of shielding bodies using PLA+W (93%) materials in high-energy electron beam treatment.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.226-232
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• 2016

The research for the improvement in math and science scores is active by the brain exercises, stress reliefs, and emotion sensitized illuminations. This principle is based on the following facts that the most effective brain turns are supported with the circumstances not only when the brain wave should keep stability and comfort in science criticism, but also when minimized stress and comfortable illumination should be adjusted in solving math problem. In this paper, in order to effectively learn mathematics and science, the most optimized simulating tests in learning conditions are conducted by using a stress relief. However, depending on the users' tastes, the effectiveness on favorite music or colors therapy have no convergency but many differentiations. Therefore, in this paper, in order to solve this problem, the proposed optimal illumination and music therapy treatment using fuzzy inference method.