EPID (Electronic Portal Imaging Device)의 유용성에 관한 고찰

이충원,박도근,최아현,안종호,송기원,Lee, Choong Won,Park, Do Keun,Choi, A Hyun,Ahn, Jong Ho,Song, Ki Weon 대한방사선치료학회 2013 대한방사선치료학회지 Vol.25 No.1

목 적: 방사선 치료 중 정확한 환자의 셋업 확인과 선량 측정용으로 사용되었던 film을 대신 하여 현재는 전자포탈영상장치(EPID)가 장착된 장비가 증가하고 있다. 이에 본 논문은 전자포탈영상장치 사용 시 자세확인의 정확성과 선량측정의 유용성을 평가해 보고자 한다. 대상 및 방법: 대한방사선치료학회, 대한방사선종양학회, Pubmed에서 "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", "In vivo dosimetry"와 같은 용어로 검색하여 획득한 50개의 자료(1997~2012)를 대상으로 EPID의 역사와 선량측정(dosimetry), 자세확인(set-up verification), EPID 특성으로 구분하여 EPID의 유용성을 분석 하였다. 결 과: EPID는 1세대 Liquid-filled ionization chamber, 2세대 Camera based fluroscopic, 3세대 Amorphous-silicon 순으로 발전하였으며, EPID 촬영 모드에는 크게 EPID mode, Cine mode, Integrated mode로 나뉜다. 필름과 EPID의 절대선량정확성 평가를 한 결과 EPID는 1%, EDR2 필름은 3% 이내로 나타나 오차 측정 정확도가 필름에 비해 EPID가 우수하다는 것을 알 수 있었고, 치료계획 시스템으로부터 계산된 기준 조사면과 EDR2 필름, EPID로 측정한 기준 조사면의 선량 분포를 중첩하여 감마 분석한 결과 필름과 EPID 모두 허용기준 3%/3 mm와 2%/2 mm에서 감마값이 1을 초과하는 화소(r%>1)가 전체 화소의 2% 이내였다. 또한 업무 부하 비교에 있어 세기조절방사선 치료에서 전 과정 QA를 수행하는데 소요되는 시간은 EDR2 필름이 약 110분, EPID가 약 55분으로 측정되었다. 결 론: 전자포탈영상장치의 이용은 선량측정과 자세확인에 있어 기존의 복잡하고 번거로웠던 film과 전리조(Ionization chamber)를 대체하기에 충분하였으며, 특히 세기조절방사선치료의 정도관리에 있어 매우 유용하고 효율적이며 정확한 선량 측정 장치임을 알 수 있었다. 또한, 전자포탈영상장치를 이용한 Cine mode 촬영은 횡격막의 움직임에 따라 유동성이 큰 폐와 간의 경우나 자세의 안정성이 불안한 직장암 환자의 경우 추가 선량 없이 실시간으로 종양의 위치를 확인 할 수 있다는 장점이 있어 최적의 방사선 치료 구현이 가능하리라 사료된다. Purpose: Replacing the film which used to be used for checking the set-up of the patient and dosimetry during radiation therapy, more and more EPID equipped devices are in use at present. Accordingly, this article tried to evaluated the accuracy of the position check-up and the usefulness of dosimetry during the use of an electronic portal imaging device. Materials and Methods: On 50 materials acquired with the search of Korea Society Radiotherapeutic Technology, The Korean Society for Radiation Oncology, and Pubmed using "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", and "In vivo dosimetry" as indexes, the usefulness of EPID was analyzed by classifying them as history of EPID and dosimetry, set-up verification and characteristics of EPID. Results: EPID is developed from the first generation of Liquid-filled ionization chamber, through the second generation of Camera-based fluoroscopy, and to the third generation of Amorphous-silicon EPID imaging modes can be divided into EPID mode, Cine mode and Integrated mode. When evaluating absolute dose accuracy of films and EPID, it was found that EPID showed within 1% and EDR2 film showed within 3% errors. It was confirmed that EPID is better in error measurement accuracy than film. When gamma analyzing the dose distribution of the base exposure plane which was calculated from therapy planning system, and planes calculated by EDR2 film and EPID, both film and EPID showed less than 2% of pixels which exceeded 1 at gamma values (r%>1) with in the thresholds such as 3%/3 mm and 2%/2 mm respectively. For the time needed for full course QA in IMRT to compare loads, EDR2 film recorded approximately 110 minutes, and EPID recorded approximately 55 minutes. Conclusion: EPID could easily replace conventional complicated and troublesome film and ionization chamber which used to be used for dosimetry and set-up verification, and it was proved to be very efficient and accurate dosimetry device in quality assurance of IMRT (intensity modulated radiation therapy). As cine mode imaging using EPID allows locating tumors in real-time without additional dose in lung and liver which are mobile according to movements of diaphragm and in rectal cancer patients who have unstable position, it may help to implement the most optimal radiotherapy for patients.

고압기류에서 액체연료 램젯엔진의 분사특성에 대한 연구

이충원 ( Choong Won Lee ),윤현진 ( Hyun Jin Youn ),유한열 ( Han Yul Yul ),오재건 ( Jae Geon Oh ) 한국액체미립화학회 2004 한국액체미립화학회 학술강연회 논문집 Vol.2004 No.-

함정내 온열 실태조사

이충원 ( Choong Won Lee ),전인기 ( In Ki Chun ),김해준 ( Hae Joon Kim ) 국군의무사령부 1992 대한군진의학학술지 Vol.23 No.1

하안검 전충결손의 재건의 치험례

오충원,여환호,이철우,양인석,신강수,박정열,Oh, Choong-Won,Yeo, Hwan-Ho,Lee, Chul-Woo,Yang, In-Seok,Shin, Kang-Soo,Park, Cheung-Yeoul 대한악안면성형재건외과학회 1992 Maxillofacial Plastic Reconstructive Surgery Vol.14 No.3

The eyelids perform many complex functions and are esthetically important, since eye is focal point of face. Tumor extirpation or trauma can lead to full-thickness eyelid defect, which Should be reconstructed as soon as possible There are a number of operation methods for lower lid reconstruction, and among them, Hughes procedure is a time-honored method. Its advantages are good cosmetic result and conjunctival repair by using eyelid structures to rebuild eyelid structures. However, this is a two-staged procedure in which the vision of the affected eye is obstructed during the interval between the operations. We experienced a case of trauma-induced full-thickness lower lid defect extending over one-third of lid length treated by Hughes method. The cosmetic and functional result was good and there was no donor site morbidity, and now we report this case with review of literatures.

교육실습생에 대한 협력교사의 지도 프로그램 연구

이충원(Choong Won Lee) 한국스포츠교육학회 2009 한국스포츠교육학회지 Vol.16 No.2

신체의 지방분포양상과 고혈압

이충원,윤능기,Lee, Choong-Won,Yoon, Nung-Ki 대한예방의학회 1991 Journal of Preventive Medicine and Public Health Vol.24 No.1

중심성 지방분포와 고혈압과의 관계와 비근 내측 피부두께가 기존의 말초성 지방분포를 나타내주는 삼두근 피부두께에 비해 더 우수한 지표가 되는지를 알아보기위해서 1990 년 해군수중 근무자 특수신체검사자 중에서 450 명을 연구자의 편의에 의해 추출되었다. 대상자의 평균 연령이 27.9 세였고 범위가 19-51세었다. 말초성 지방분포의 지표로 삼두근과 비골 내측 피부두께를, 중심성 지방분포는 견갑골하 피부두께와 이것과 삼두근으로 이루어진 비와 차이로 측정을 했다. 신체의 지방분포를 나타내는 피부두께와 이 들을 기준으로한 비와 차이의 지수를 4 분위수로 나누어 첫 1/4 분위수를 기준으로 하고 나머지 3 가지 수준을 기준에 비교를 했다. 연령과 전체적인 비만도를 다중지수분석으로 통제를 한 후 고혈압과의 관계에서 견갑골하 피부두께가 기준인 1/4 분위수와 비교해 보아 2/4, 3/4, 4/4 분위수로 증가함에 따라 각각 2.05(95 % 신뢰구간 1.18-3.59), 2.02(1.06-3.86), 4.00 (1.99-8.06) 의 유병비차비를 보였다. 견갑골하 피부두께와 비골 내측 피부두께의 차이 역시 4/4 분위수가 되었을 때만 2.45 (1.28-4.68)의 비차비를 보였다. 그 외의 삼근 피부두께와 비근내측 피부두께에서는 기준에 비교해 보아 1 을 포함하지 않은 비차비는 없었다. 연령과 전체적인 비만도를 조정한 비차비는 조정치 않은 조비차비에 비해 대체적으로 조금 감소했다. 비근 내측의 피부두께는 삼두근 피부두께에 비교해보아 더 우수한 말초성 지방분포를 대표해주는 피부두께로 보였다. 이러한 결과는 전체적인 비만도 수준과는 독립적으로 견갑골하 피부두께로 측정된 중심성 지방분포가 고협압과 관계가 있으며 우수한 중심성 지방분포를 나타내주는 지표가 됨을 시사해주는 소견이다. This study examined the cross-sectional association of central body fat distribution with hypertension as well as the superiority of medial calf skinfold measured as peripheral fat distribution over the conventional triceps skinfold using 450 Korean Navy divers selected by authors' convenience in 1990. Their mean age was 27.9 and range of it was 19-51. The centrally located body fat was approximated by subscapular skinfold and peripherally located fat by triceps and medial calf skinfolds. Four indices were constructed from these skinfold measures to reflect central versus peripheral fat distribution pattern : 2 ratios and 2 differences. After controlling age and overall obesity (body mass index), prevalance odds ratios of the 2/4, 3/4, 4/4 quartiles of subscapular skinfold comparing with lowest 1/4 quartile were 2.05(95% confidence interval, CI 1.18-3.59), 2.02(95% CI 1.06-3.86), 4.00 (95% CI 1.99-8.06) respectively. The difference of subscapular and medial calf skinfolds was associated with hypertension (odds ratio 2.45, 95% CI 1.28-4.68 comparing highest with lowest quartiles). Triceps and medial calf skinfolds alone did not show any odds ratio not including unity. The adjusted odds ratios were generally reduced in small magnitude compared with crude odds ratios not adjusted for age and overall obesity. The medial calf skinfold appeared to be more representative of peripheral body fat distribution than triceps skinfold. These findings suggest that central fat distribution rather than peripheral distribution is associated with hypertension independent of age and overall level of obesity and medial calf skinfold may replace conventional triceps skinfold in predicting peripheral distribution of body fat.

수직 감염된 B형 간염 바이러스 Promoter 유전자의 변이 분석

이충원,한영나,이정화,이광철,하영미,Lee, Choong-Won,Han, Young-Na,Lee, Jung-Hwa,Lee, Kwang-Chul,Ha, Young-Mee 대한소아소화기영양학회 2002 Pediatric gastroenterology, hepatology & nutrition Vol.5 No.1

Hepatitis B viral infection which affect about 10% of Korean population manifests asymptomatic carrier, chronic hepatitis and liver cirrhosis and even associates with hepatocellular carcinoma. Clinical manifestations induced by hepatitis B virus vary depending on the degree of immune response by cytotoxic T cells against viral epitope-presenting liver cells. Since hepatitis B virus presents high rate of mutaton that might change the presented epitope and eventually alter immune response, viral mutations, especially in promoters and enhancers, have an important implication in hepatic inflammation and viral replication. To identify mutations related to the hepatic inflammation, we investigated sequence variations of hepatitis B viral promotor regions in the presence or absence of symptoms in hepatitis B carriers. For this, sera from persistently hepatitis B virus-infected mother-child pairs were collected. After PCR amplifiation of all hepatitis B viral promoters (C promoter, S1 promoter, S2/S promoter, X promoter) using serum DNA from each pair, viral promotors were sequenced by automatic sequencer and then sequence data were analyzed by ClustalW. In most cases, the dominant type of maternal virus was transmitted to the child. However, in some children, some new host specific viral variants could be observed in Cp, S1p and S2/Sp. The mutations in C promoter did not seem to be vertically transmitted but arose in new host independently after the wild type had been transmitted. Enhancer I containing X promoter revealed high host specific variations as has been reported before. Two S promoters, S1p and S2/Sp, have shown some point mutations in children, but no deletion mutations were detected as in chronic hepatitis patients in whom deletion mutations are frequently found. In conclusion, the children with the vertically transmitted hepatitis B virus mostly retain the dominant type virus that had been transmitted. However, host specific variants tended to accumulate over time, possibly as clinical symptoms develop.

일부 60~64세 농촌 인구에서 사회조직망과 고혈압

이충원,조희영,이미영,김귀연,박종원,강미정,서석권,Lee, Choong-Won,Cho, Hee-Young,Lee, Mi-Young,Kim, Gui-Yeon,Park, Jong-Won,Kang, Mi-Jung,Suh, Suk-Kwon 한국농촌의학지역보건학회 1998 농촌의학·지역보건 Vol.23 No.2

농촌의 전통적인 사회조직망을 반영해주는 변수들과 고혈압과의 관련성을 규명하기 위해 달성군 60-64세 노인을 대상으로 1996년 4월부터 9월까지 일대일 면담방법으로 조사를 실시하였다. 사회조직망을 반영해주는 변수로 결혼, 규칙적인 종교행사 참석, 친한 친구 및 친척 수, 구성원으로 있는 모임 수, 자식 및 손주 수 그리고 형제 수 등이 선정되었다. 고혈압은 고혈압력을 가진 자, 수축기 혈압이 100 mmHg 이상 또는 이완기 혈압이 95 mmHg 이상의 기준 중 최소한 하나의 기준을 만족하는 자로 정의하였다. 최종 자료 분석에 이용된 대상자는 총 958명으로 남자 440명, 여자 518명이었다. 남자의 당일지수 분석에서 친구가 없는 자에 비해 1-4명 가진 자가 0.43배 (95% 신뢰구간 0.19-0.96) 더 고혈압일 확률이 더 낮았으며, 자식이 0-1명인 자에 비해 2-3명, 4명, 5명 이상에 따라 비차비가 각각 0.21 (95% 신뢰구간 0.06-0.72), 0.14 (95% 신뢰구간 0.04-0.49), 0.24(95% 신뢰구간 0.07-0.82)로 고혈압일 확률이 더 낮았다. 반면에 여자에서는 통계적으로 유의한 사회조직망 구성 변수는 없었으며 손주가 없는 자에 비해 5-9명 가진 자의 비차비가 0.42 (95% 신뢰구간 0.17-1.02)로 경계성 유의성을 나타내었다. 연령, 교육수준, 비만도, 흡연 및 음주를 다중지수회귀분석으로 통제를 한 후 비차비의 변화를 관찰하였다. 남자에서 단일변수 분석에서처럼 친구 수와 자식 수가 통계적으로 유의한 비차비를 나타내었으며 단일연수 분석의 결과에 비해 상관의 강도가 더 높아졌다. 특히 친척 수는 통계적인 유의성을 획득하였으며 친척이 없는 자에 비해 가진 자는 0.44-0.50의 비차비를 나타내었다. 여자에서 대체로 단일변수 분석에서와 같은 결과를 나타내었으나 손주 수는 없는 자에 비해 5-9명을 가진 자의 비차비자 0.42에서 0.37 (95% 신뢰구간 0.14-0.95)로 상관성이 더 높아졌으며 통계적인 유의성 역시 경계선에서 유의성을 획득하였다. 이러한 결과는 사회조직망 중 일부 특정한 구성요소가 고혈압과 관련이 있으며 남녀간에 관련 구성 요소가 서로 차이가 남을 시사한다. Face-to-face interviews were carried out to investigate the relationship between social networks and hypertension in 958 rural residents(males=440, females=518) aged 60-64 of a community-dwelling sample of Dalsung County from April to September in 1996. Eight elements of social network were measured : marital status, regular religious attendance, membership in groups, number of friends, relatives, siblings, children, grandchildren. Hypertensives were defined as meeting at least one of following criteria : hypertension history, systolic blood pressure more than 160 mmHg, diastolic blood pressure more than 95 mmHg. In univariate logistic regression for males, having 1-4 friends vs. none showed odds ratio 0.43 (95% Confidence interval CI 0.19-0.96) and having 2-3, 4 and more than 5 children had reduced prevalence of hypertension with odds ratios 0.21 (95% CI 0.06-0.72), 0.14 (95% CI 0.04-0.49), 0.24 (95% CI 0.07-0.82), respectively when compared with persons without children. In females, there was no elements of social network statistically significant. Having 5-9 grandchildren vs. none showed a marginally significant odds ratio 0.42. In multivariate logistic regression models for males with adjustment for age, education, body mass index, smoking and drinking, number of friends and children showed increased odds ratios and number of close relatives gained a statistically significant odds ratios (0.44-0.50). In females, the adjustment yielded little changes of odds ratios except number of grandchildren which gained a statistically significance. These results suggest that only a certain elements of social network may be associated with reduced risk of hypertension and they may be different between genders in rural resident aged 60-64.

민간임대주택 거주자의 주거만족도가 매입의향에 미치는 영향 연구 : 수도권 화성시와 지방 충북 청원군 중심으로

강충원(Kang, Choong-won),이성근(Lee, Sung-Gun) 한국부동산정책학회 2015 不動産政策硏究 Vol.16 No.1

If you look at the Government s housing supply statistics, the total housing supply in 2013 (completion basis) was 18,968,800 units. In this same year, rental-housing inventory was only 1,616,221 units. Among them, the private sector of rental housing totaled 491,601 units. Rental housing supply was about 8.5% of the entire housing supply. Rental housing in the private sector was only 2.5% of the entire housing supply. For low-income and middle-income people to meet the ever-increasing demand of leases for housing, the primary quantitative supply should be required for residential stability, but considering the scope of environmental changes, the supply of customized rental homes and lease sales should more fully satisfy the applicant s housing needs and demands. This study has categorized and investigated two specific groups; both the metropolitan and local areas. The comparative analysis has been done on residential satisfaction and purchase intention through empirical research on each group. Therefore, the following conclusions were drawn. There should be housing assistance and subsidized grants to support rental-housing tenants; and for purchased property, there should be a mortgage program to amortize the necessary loan. In addition, there should be rental housing supply diversification as well as improvement in the residential environment equilibrium. The average income was one of the most important factors in the decision to purchase a rental property in the metropolitan area. On the other hand, in the province area, the most important factor was the proximity to schooling facilities. There are other factors according to regional differences, these common factors include: schooling facilities, accessibility to convenient facilities, security, neighborhoods and so on. The willingness of purchasing appeared to be higher; the more satisfied consumers were regarding these common factors. Therefore, the location is critical. In order to make the existing residents purchase the house, the rate of settlement increase, the parking facilities, other amenities, school facilities, and accessibility are all necessary in order for rental housing to be purchased. Moreover, good neighborhoods, security, and crime prevention will greatly increase the chance of existing housing residents to make future purchases.

초임 체육교사가 인식하는 "잘 한 수업" 분석

이충원(Choong Won Lee),백종수(Jong Soo Paek) 한국스포츠교육학회 2008 한국스포츠교육학회지 Vol.15 No.4