중국 채소류 생산 관리체계 분석 -산동지역 고추, 마늘, 양파 농가 사례조사 결과-

하두종 ( Doo Jong Ha ),유창환 ( Chang Whan Yu ),최칠구 ( Chil Ku Choi ),조성주 ( Sung Ju Jo ),이종수 ( Jong Zhu Li ) 한국국제농업개발학회 2015 韓國國際農業開發學會誌 Vol.27 No.5

1. 본 연구는 중국 산동성의 평도시(平度市) 및 신강성 집단재배농장을 대상으로 주요 채소 농산물인 고추, 마늘, 양파에대하여 한국과 중국의 생산 관리체계 및 기술 수준을 비교ㆍ분석하였다. 2. 고추의 경우 한국은 묘를 구입하여 정식하는 비율이 높지만 중국은 대부분 자가 채종 후 자가 육묘를 하는 체계이다. 가장 특징적인 것은 한국은 수확을 10일 간격으로 5 ~ 6회 하지만, 중국은 일시 수확하여 수확노동력을 줄이고 있다. 고추의 경영비와 생산비 비교에서는 각각 한국이 3,975원/kg,11,686원/kg이며, 중국은 519원/kg, 1,895원/kg으로 한국의 경영비가 7.3배, 생산비는 6.2배 차이가 나는 것으로 조사되었다. 3. 중국의 마늘 파종량은 한국에 비해 3배 이상으로 밀식파종을 한다. 재배 이랑은 한국은 넓은 이랑이며, 중국은 2줄 좁은 이랑에서 재배 하고 있다. 멀칭은 한국이 기계멀칭을 64%하고 있으나 중국은 인력을 이용한 멀칭을 하고 있다 마늘의 경영비와 생산비 비교에서는 각각 한국이 1,128원/kg, 2,049원 /kg이며, 중국은 310원/kg, 686원/kg으로 경영비는 3.6배, 생산비는 3.0배 차이가 나는 것으로 분석되었다. 4. 양파는 중국이 한국보다 경지기반은 좋으나 호당 경지면 적은 0.14 ha로 매우 영세하다. 한국은 복비와 유기질 비료를 사용하고 방제를 3 ~ 5회하는 반면, 중국은 계분을 사용하고, 살균, 살충, 제초 방제는 1회만 실시하고 있다. 육묘는 중국과 한국이 모두 구입종자를 이용한 자가 육묘를 하는 동일한 생산체계이다. 양파의 경영비와 생산비 비교에서는 각각 한국이 199원/kg,334원/kg이며, 중국은 46원/kg, 98원/kg으로 한국보다 경영비는 4.3배, 생산비는 3.4배 차이가 있은 것으로 나타났다. This study was carried out to analyze the Chinese vegetable production system and to compare it with the adopted system in Korea. Farm producing pepper, garlic and onion in Sandong and Singang were surveyed. For pepper production, Korea farm purchased the planting materials while, China farm produced their own seeds and seedlings. Also, the most significant difference was the one time harvesting in China, while Korea usually harvests 5 ~ 6 times within 10 days term per year with an increase in production. The management and production cost were observed to be 3,975 won/kg, 11,686 won/kg for Korean pepper, but China has low cost by 519 won/kg, 1,895 won/kg. An amount of garlic seed in China was more than three times that of Korea. Korea covered the wide furrow with mulching plastic and used machines that raised the production rate by 64%. However, Chinese depends on the human labor and make narrow furrow to increase the productivity. The management and production cost were 1,128 won/kg, 2,049 won/kg for Korean garlic, while China has low cost by 310 won/kg, 686 won/kg respectively. To cultivate onion, the land condition of China was better than Korea having an average farm size of 0.14 ha smaller than Korea. Two nations were compared having the same seedling production system that buy the seed at the market and seedling their own land. Likewise, the management and production cost observed as 199 won/kg, 334 won/kg for Korean onion, while Chinese cost was lower by 46 won/kg, 98 won/kg. It is concluded that the good producing system of China such as pepper one-time harvesting system should be adopted to korean farm system to reduce cost.

大學 敎養體育 改善方案 硏究

金永煥,河永俊,文成喆 仁荷大學校 스포츠科學硏究所 1990 論文集 Vol.2 No.-

The purpose of this study is plan improvement for General Physical Education. The subjects of questionnaire are student of college, director of company and college all over the country. There are two aspects for improvement plan of General Physical Education by curriculum and education environment . 1, The improvement plan for general physical education The purpose of general physical education in college are as follows : (1) Education for independence. (2) Education for devotion to the welfare of mankind. (3) Education for leadership. (4) Education for service of democracy development. (5) Education for ideal realization of mankind. 1) The aspect of curriculum (1) The end of instruction (1) Education for fitness (2) Education for team-work (3) Education for motor-skill (4) Education for body-balance (5) Education for leadership of sports for all (2) The contents of instructions (1) Student can chose an event a) An events of lifetime sport; swimming, Tennis, Bowling, Table tennis, Fencing, Ski Shooting, Basket ball, Golf, Archery, Riding, etc. b) An events of official sport; Soccer, Volley ball, Basket ball, Table tennis, Base ball, Climbing, etc. (2) Set up of instruction for season and intensive course. (3) Management of practical instruction of 3 grade. 1- For fitness. 2- For technique of personal and team. 3- For game management (4) Domain of Sports Science are as follows: (a) Physical Education for man's life. (b) Play, Game, Sports. (c) Recreation. (d) Physical Education for health. (e) Sports physiology. (H) Sports amatomy and Biomechanics. (g) Sports psychology. (h) Sports sociology. (i) Fitness (j) Team-work (k) Body-blance (l) Game rule (3) The method of instruction (1) A class compose less than 40. (2) Students wear sports uniform when practical instruction. (3) Students prepare instrument for practical instruction but expensive instrument lead or aid by authority (4) Students prepare textbook. (5) A supporting instrument for practical instruction prepare as follows. (a) Instrument for audiovisual. (b) Instrument for evaluation and measurement. (c) Instrument for supporting of playing. (e) Utilization of assistant teacher for practical instruction (4) The evaluation of instruction (1) Evaluation time is to be measured at any time, midterm and term examination by items. (2) Evaluation item are as follows? (a) Technique ability. (b) Presense and absense matters. (c) Written examination and report. (d) Attitude for research , (e) Readness of sports uniform and instrument (f) Fitness. (g) Team-work. (h) Body-balance. (i) Independence. (j) Service ship. (3) Reference of mark by each other measure of students-team-work, independence, service-ship 2) Aspect by education environment (1) College rule (1) General physical education is to be considered as required subject (2) Term of general physical education is from 2 to 4 semester. (2) An instrument and institution (1) Gymnasium (2) Instrument for practical instruction (3) Supporting instrument (a) Audiovisual for practical instruction (b) Instrument for evaluation (Motor skill and Fitness) (c) Instrument to support of playing. (4) Aid to use of private possessions. (3) Improvement of management post for, general Education (1) Subdivision and Specility of management post. (2) Manage to control fitness all through life. (3) Management of personal data room.

탈지 환원유에서 Bifidobacterium longum의 호기성 고농도 배양에 관한 연구

구동환,하상우,조수현,박기문,김동운,강국희 성균관대학교 생명과학자원연구소 1997 生命資源科學硏究 Vol.4 No.1

The objectives of this study were to investigate the optimal condition for growth and highly concenterated culture of Bifidobacterium longum (Bif longum). The effects of additives were compared with titratable acidity and viable cell counts, and 10% reconstituted skim milk (no additive) was used as a control. Correlation coefficient for the growth of Bif. longun between CO_2 anaerobic jar method and overalaid medium method was R=0.99. When 1% Bif. longurn was inoculated on 12%, 14%, and 16% reconstituted skim-milk, viable cell counts were 8.60, 8.89, and 8.93 Log CFU/ml, respectively. When Lactose, Glucose, Glucosamine, Fructose, Peptone, N-acethyl-D-glucosamine, D-galactose, and liver extract were added to 16% reconstituted skim-milk, the viable cell counts were 8.61, 9.05, 9.15, 9.24, 8.82, 9.75, 9.17, and 9.64 Log CFU/ml, respectively. Therefore, D-galactose, liver extract, and N-acethyl-D-glucosamine were selected as final additives. When Bif longum was inoculated on Fermentor-I (16% reconstituted skim milk containing 0.1% yeast extract, 0.5% D-galactose and 0.5% liver extract), Fermentor-II (16% reconstituted skim milk containing 0.190% yeast extract, 0.590% N-acethyl-D-glucosamine and 0.5% liver extract), Batch culture-I (16% reconstituted skim milk containing 0.1% yeast extract, 0.5% D-galactose and 0.5% liver extract), and Batch culture-II (16% reconstituted skim milk containing 0.1% yeast extract, 0.5% N-acethyl-D-glucosamine and 0.5% liver extract), viable cell counts were 10.46, 9.37, 9.03, and 8.83 Log CFU/ml, respectively. Although liver extract was the important additive for the highly concentrated culture of Bif. longum in this study, it caused serious off-flavor when liver extract-1 (contained cell mass) was added to Fermentor culture. However, flavor was improved when liver extract-2 which was removed cell mass, was used instead of liver extract-1. Addition of 2% liver extract-II and 1% D-galactose had the similar effect with addition of 0.5% Liver extract-I and 0.5% D-galactose on the growth of Bif. longum.

응급실에서의 확산강조 자기공명 영상

정성필,이석우,양영모,하영록,김승환,유인술 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: This study was designed to review the cases of patients who had undergone diffusion-weighted magnetic resonance imaging(DWI) in the emergency department(ED), and to investigate its clinical usefulness and current indications. Methods: We analyzed the cases of 152 consecutive patients who underwent DWI in the ED from Jan to Mar 2001. DWI was obtained with the use of a multislice, single-shot, spin-echo plana imaging technique(GE SignaR). Imaging time was less than one minute. The medical records, the DWI films and the computed topography results were reviewed. We investigated the chief complaint, initial findings of physical examination, final diagnosis, decision-making department, interval from admission to imaging, and DWI findings. Results: DWI showed positive findings of high signal intensity in 84 patients(55.3%). Among the 68 patients who yielded a negative result, false negative occurred with 12 patients(17.6%): 10 lacunar infarctions, a pons infarction, and a brainstem infarction. Eleven patients were determined as having a cerebral hemorrhage, all of whom showed the abnormal finding of a mixed signal in DWI. The sensitivity and the specificity of DWI to rule out stroke were 85.5% and 98%, respectively. Current indications for DWI in our ED are age older than 60, alert mental status, and one of the symptoms or signs among lateralyzing sign, language disturbance, and dizziness/vertigo. Conclusion: DWI was highly specific to rule out stroke, so emergency care professionals should be familiar with this new technology. Further prospective study is required to determine the proper indications and clinical usefulness of DWI in the ED.

체외 방사선조사시 인체 말초혈액 임파구의 염색체이상 빈도에 관한 연구

안용찬,하성환 대한방사선 방어학회 1993 방사선방어학회지 Vol.18 No.2

급성 전신 및 부분 피폭시 피해자들에 대한 치료방침의 결정에 있어 참고자료로서 사용하기 위하여 저자들은 체외에서 말초혈액을 60 Coγ-선으로 2Gy에서 12Gy까지 방사선 조사하여 말초 임파구에서 관찰되는 염색체이상의 빈도와 방사선량과의 관계를 실험적으로 연구하였다. 관찰된 세포중 불안정 염색체이상(dicentric 염색체, ring 염색체, acentric fragment쌍)이 나타난 세포의 비율은 2Gy에서 32%, 4Gy에서 47%, 6Gy에서 80%, 8Gy에서 94%, 10Gy이상에서는 100%였다. 급성 전신 피폭시 평균 흡수선량을 반영하는 지표인 Ydr은 2Gy에서 0.373, 4Gy에서 0.669, 6Gy에서 1.734, 8Gy에서 2.773, 10Gy애소 3.746 그리고 12Gy에서 5.454였다. 방사선량(D)과 염색체이상(dicentric 염색체와 ring 염색체의 합) 빈도(Ydr)와의 관계는 Ydr=9.322×10- ²/Gy×D+2.975×10-²/Gy²D²로 나타났다. 신체의 부분피폭시의 선량 및 과거의 피폭선량을 계산할 때 사용하는 지표인 Qdr은 2Gy에서 1.166, 4Gy에서 1.436, 6Gy에서 2.173, 8Gy에서 2.945, 10Gy에서 3.746, 그리고 12Gy에서 5.454였다. 이와 같은 선량측정방법의 신빙도를 검증하기 위하여 신체의 부분에 균일한 선량분포의 1.8Gy, 2.5Gy 및 7.0Gy의 방사선치료를 일회 받은 환자들로부터 구한 Qdr은 각각 1.109, 1.222, 2.222였으며 이로부터 Qdr=Ydr/(1-e -Ydr)의 관계식을 이용하여 계산해 낸 피폭선량은 1.52Gy, 2.48Gy 및 6.54Gy로서 실제 조사한 선량과 매우 근사한 결과를 얻었다. As guides to decision-making in the management of the victims in case of acute whole body or partial body radiation exposure, we studied the relationship between radiation dose and the frequency of chromosomal aberrations observed in peripheral lymphocytes that were irradiated in vitro with ??Co γ-rays at dodws ranging from 2Gy to 12Gy. The yields of cells with unstable chromosomal aberrations (dicentric chromosomes, ring chromosomes, and acentric fragment pairs) were 32% at 2Gy, 47% at 4Gy, 80% at 6Gy, 94% at 8Gy, and 100% at 10Gy and over. Ydr, which reflect average dose to the whole body in case of acute whole body exposure, were 1.373 at 2Gy, 0.669 at 4Gy, 1.734 at 6Gy, 2.773 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. The relationship between radiation dose (D) and the friquency of dicentric plus ring chromosomes per cell(Ydr) could be expressed as Ydr=9.322×10-²/Gy×D+2.975×10-²/Gy²×D². Qdr, which are used in estimating dose of partial body exposure and dose of past exposure, were 1.166 at 2Gy, 1.436 at 4Gy, 2.173 at 6Gy, 2.945 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. To see how confidently this dosimetry system may be used, we obtained Qdr values from those who received one fraction of homogenous partial body irradiation of 1.8Gy, 2.5Gy, and 7.0Gy therapeutically; in vivo Qdr values were 1.109, 1.222 and 2.222 rewpectively. The estimated doses calculated from these in vivo Qdr values using the equation Qdr=Ydr/(1-eYdr) were 1.52Gy, 2.48Gy, and 6.54Gy respectively, which were very close to the doses actually given.

방사선 치료후 시간경과에 따른 염색체이상 빈도의 변화

송명재,하성환,이춘자,김희근,김미숙 대한방사선 방어학회 1994 방사선방어학회지 Vol.19 No.1

임파구의 염색체이상 빈도로부터 피폭자의 흡수선량을 구하는 방법은 사고로 인해 급성피폭을 받는 경우 유용하게 사용될 수 있다. 그러나 방사선 피폭 후 시간이 경과함에 따라 불안정 염색체이상을 가진 임파구는 감소하게 된다. 이에 방사선 치료후 시간 경과에 따른 불안정 염색체이상 빈도의 변화를 규명하고자 한다. 전골반에 50.4 Gy의 방사선 치료를 받은 총 20명의 자궁경부암 또는 자궁내막암 환자를 대상으로 41개의 검체를 얻었다. 채혈의 시기는 방사선 치료후 1일 3주, 6주, 12주, 24주, 52주, 104주, 156주, 208주, 520주로 하였다. 이들 말초혈액의 임파구에 대해 전혈미세배양을 실시한 후 임파구의 불안정 염색체이상을 관찰하여 Ydr, Qdr, Qdra를 얻었다. Ydr 값은 방사선 치료가 끝난 직후부터 3주까지 plateau를 보였고 이후 감소하는 경향이었다. Ydr의 평균값은 치료후 3주에 0.29에서 급격히 감소하여 2년후 0.05로 감소하였으며 이후 5년까지 서서히 감소하였다. 회귀분석을 실시한바 Ydr = 0.259×exp(-0.0429T)+0.0560×exp(-0.00106T)(time in weeks)로 나타났다. Qdr값은 치료 직후부터 24주까지 1.51 전후로 거의 변화가 없었으며 이후 감소하여 52주 이후에는 1.17 전후로 거의 일정하였다. Qdra 값은 치료 직후부터 12주까지 1.10 전후이며 이후 감소하여 52주 이후에는 0.81 전후였다. 피폭 후 시간경과에 따른 Ydr 값의 감소는 두 component exponential 모델을 잘 맞고 이 식을 이용하여 생물학적 선량측정이 가능하다. Qdr 값 및 Qdra 값은 피폭후 시간경과가 짧은 경우 피폭선량을 추정하는 지료로 사용할 수 있다. It is good method to use frequency of chromosome aberration in lymphocytes for a biological dosimetry in cases of accidental exposure to radiation. But in cases of past edposure, biological dosimetry is limited because the friquency of aberration decreases by time after exposure. To provide a basic data for estimationof past radiation exposure, the changing pattern of frequency of unstable chromosome aberration by time interbal after exposure was studied. Observation was made on peripheral lymphocytes of 41 blood samples from 20 patients treated for uterine cervical carcinoma and endometrial caricinoma. The patients received 50.4 Gy radiation to whole pelvis. Elapsed times after the completion of radiation therapy were 1 day, 3, 6, 9, 12, 24, 52, 104, 156, 208, 260 and 520 weeks. All the blood sample were microcultured. The Ydr, Qdr and Qdra were calculated form frequency of unstable aberration. Ydr did not decrease for 3 weeks after radiation therapy, and thereafter, decreased very rapidly and reached 0.05 at two years after radiation therapy and decreased very slowly until 5 years after radiation therapy. Relationship between unstable chromosome aberration and time interval after radiation therapy was described as Ydr = 0.2590.259×exp(-0.0429T)+0.0560×exp(-0.00106T)(time in weeks) Qdr remained constant at 1.51 until 24 weeks after radiation therapy and then decreased to 1.17 at 52 weeks. Therafter, it did not change. Qdra remained constant at 1.10 for 12 weeks after radiation therapy and decreased to 0.81 at 52 weeks. Thereafter, it remanined constant. Two superimposed exponential Ydr disappearance rate wuggests that it is possible to calculate the past exposure dose. When the elapsed time after exposure is short, Qdr and Qdra are useful papameters for biological dosimetry for past radiation exposure.

레이저 박피술의 피부면적 감소효과와 레이저 punch out 병변의 치유에 대한 실험적 연구

강동희,윤을식,구상환,안덕선,박승하 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

An experimental study was designed to analyze the surface reduction effect of ultrapulse carbon dioxide laser on the skin of guinea pigs receiving laser resurfacing. Two squares of skin measuring 3x3 ㎠ were designed on each side of the abdomen of guinea pigs(n=10). Five animals received laser resurfacing on their abdomen at energy of 250mJ/5 watt, and five other animals received 500 mJ/5 watt. On each animal, the left side square was treated with one pass of a CO2 laser, and the right side q=square was treated with two passes using a C.P.G. scanner. The size of the resurfacing area was determined by celluloid overlays at 1,2,3,4 and 6 weeks. Immediately following laser resurfacing, the area was decreased to 69%(left side) and 56%(right side) of the designed area in the 250 mJ/5 watt group, and 59% and 40% in the 500mJ/5 watt group. After 6 weeks, the resurfaced area had been reduced to 70% and 56% of the designed area in the 250mJ/5 watt group, and 60% and 40% in the 500mJ/5 watt group. As a result, the effect of surface reduction by CO2 laser resurfacing increased at a higher power and when more passes of the ultrapulse carbon dioxide laser were applied. The laser treated skin continued to maintain its contracted dimensions. These findings suggest that ultrapulse carbon dioxide laser may be an effective treatment method for rhytides. Another experiment was performed on multiple punch-out lesions on guinea pig skin(n=2) with 1,2,3 mm collimated hand pieces for the purpose of determining a new laser treatment method. After 4 weeks, on gross and histological examination, there were no differences in the healing of multiple punch-out lesions and the healing of punch-out lesions was complete without any scarring. These findings suggest that the laser punch-out method can be used for the treatment of acne scars.

몬순기후와 복잡지형의 특성을 갖는 광릉 산림유역의 물과 탄소순환에 대한 교차규모 연구로부터의 교훈

이동호 ( Dong Ho Lee ),김준 ( Joon Kim ),김수진 ( Su Jin Kim ),문상기 ( Sang Ki Moon ),이재석 ( Jae Seok Lee ),임종환 ( Jong Hwan Lim ),손요환 ( Yo Whan Son ),강신규 ( Sin Kyu Kang ),김상현 ( Sang Hyun Kim ),김경하 ( Kyong Ha Kim 한국농림기상학회 2007 한국농림기상학회지 Vol.9 No.2

광릉 슈퍼사이트에서 대기와 식생간의 에너지와 물질교환 규명은 지형과 식생의 복잡성으로 인해 많은 기술적인 어려움에 직면하고 있다. 따라서 KoFlux 연구에서는 상호보완적인 다중 분야의 연구를 통해 이러한 어려움을 극복하기 위한 시도를 해 오고 있다. 본 논문에서는 현재 진행중인 KoFlux 연구의 예비결과 중 특히 광릉사이트에서의 물/탄소수지, 물과 탄소순환의 상호관련성 그리고 몬순기후하의 생태계에서 탄소순환에 미치는 수문학적 요인의 중요성에 대해 중점적으로 논의하고자 한다. 광릉낙엽활엽수림의 순생태생산량 (NEP)은 광범위한 생태학적 연구결과에 따르면 약 ~2.6 t C/ha/y로 예상된다. 이를 미기상 플럭스 관측 결과와 함께 고려할 때 광릉 산림은 탄소의 중요한 육상흡원으로서 기능함을 예상할 수 있다. 다양한 생태수문 관측에 의해 규명된 유역단위 물수지에 의하면 연단위 전체강수량의 약 30-40%가 증발산 (ET)에 해당함을 나타내고 있다. 광릉산림의 대표적인 수종인 졸참과 서어나무의 잎에서 얻어진 탄소 안정동위 원소 조성에 근거하여 계산된 식물 성장기간의 평균 물 이용효율(WUE)은 약 ~12 μmol CO2/mmol H2O에 해당된다. 얻어진 증발산량과 물이용효율은 유역단위의 생태계 생산량을 산출하는데 이용될 수 있다. 나이테 성장량과 토양호흡량의 연단위 변화는 강수량과 강수의 패턴에 의해 크게 영향을 받음을 보이고, 이는 몬순기후에 영향을 받는 동아시아 지역 생태계에서 탄소 순환과정이 수문학적 조건과 밀접한 상관관계를 가짐을 지시한다. 연구지역의 공간적 특성을 정량화하기 위해 관측지의 구조 및 기능적 단위를 규명하기 위한 연구가 진행되고 있고 이를 통해 서로 다른 시공간 규모에서 진행되고 있는 연구의 결과물을 체계적으로 연결 통합하고 나아가 보다 광역적인 규모에서 대표적인 물/탄소 수지를 산출하기 위한 연구가 시도되고 있다. KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ~2.6 t C ha-1 y-1. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric CO2. The catchment scale water budget indicated that 30~40% of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about 12 μmol CO2/mmol H2O with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

Development of the Algorithm for On-line Dosimetry System for High Energy Radiation Treatment

Ha,Sung Whan,Wu,Hong-Gyun 대한방사선 방어학회 1997 방사선방어학회지 Vol.22 No.3

목적 : 고에너지 방사선치료용 on-line 선량측정시스템의 개발의 일부로서, 측정된 투과선량을 이용하여 종양선량을 계산하는데 필요한 알고리즘의 개발이 목적이다. 방법 : 첫번째로 다양한 크기의 조사야 (FS), 다양한 두께의 phantom (Tp), 다양한 거리의 phantom to chamber distance (PCD)에서 6 MV 및 10 MV X-선에 대하여 특수 제작한 water phantom을 대상으로 phantom 의 후방에서 투과선량을 측정하여 기본적인 beam data를 얻었다. 선원-측정기간 거리는 150cm으로 고정시켰다. 측정은 0.125cc ion chamber를 이용하였다. 두번째로 노출환경 (조사야의 크기, phantom의 두께, PCD)과 측정치와의 상관관계에 대한 알고리즘을 개발하고, 마지막으로 측정치와 알고리즘에 의한 예상치를 비교하여 알고리즘의 정확성을 평가하였다. 결과 : 측정데이터를 이용하여 회귀분석을 시행해서 두가지 알고리즘을 개발하였다. 알고리즘 1은 PCD에 대한 2차 함수와 A/P (area-perimeter ratio)에 대한 3차 함수로 이루어져 있으며, 알고리즘 2는 log(A/P)에 대한 3차 함수화 PCD에 대한 3차 함수로 이루어져 있다. 알고리즘 1에서는 측정치와 예상치의 오차가 1.0% 미만이었고, 알고리즘 2에서는 측정치와 예상치의 오차가 거의 0.5%미만이었다. 또한 알고리즘 2는 알고리즘 1을 사용할 때보다 적은 data를 가지고서도 더욱 정확하게 fitting 할 수 있었다. 따라서 fitting 상수들을 구하는데 필요한 측정시간을 알고리즘 1을 사용할 때보다 반으로 줄일 수 있었다. 결론 : phantom의 후방에서 측정한 투과선량을 이용하여, 임의의 Tp, PCD, FS에서 투과선량을 정확하게 예측할 수 있는 두가지의 알고리즘을 개발하였다. 향후 보조 장치에 의한 영향, 조사야 차폐의 영향, 신체조직의 조직특성 (불균일도, inhomogeneity), 신체 형태의 굴곡에 대한 연구를 완성하면 매치료시마다 종양에 흡수된 방사선량을 확인할 수 있는 on-line dosimetry가 가능할 것이다. Purpose : The objective of this study is to develop an algorithm for estimation of tumor dose using measured transmission dose as a part of the development of on-line dosimetry system. Materials and Methods : Data of transmission dose were measured under various FS, Tp and PCD with a special water phantom for 6 MV and 10 MV X-ray. SCD (source-chamber distance)was set to 150 cm. Measurements were conducted with a 0.125 cc ion chamber. Results : Using measured data and regression analysis, two algorithms were developed for estimation of expected reading for measured data. Algorithm 1 consisted of the quadratic function of PCD and the tertiary function of A/P (area-perimeter ratio). Algorithm 2 consisted of the tertiary function of log(A/P)and the tertiary function of PCD. Algorithm 2 required less data set and was more accurate in comparing expected and observed dose. Conclusion : Using the algorithm developed, transmission dose can be estimated for any exposure condition, i.e. any given Tp, PCD and FS with high accuracy. To complete this algorithm, fruther developments are needed regarding the beam modifying device, the tissue inhomogeneity and the irregular body surface.

The effect of photon energy on intensity-modulated radiation therapy (IMRT) plans for prostate cancer

Sung, Won-Mo,Park, Jong-Min,Choi, Chang-Heon,Ha, Sung-Whan,Ye, Sung-Joon The Korean Society for Radiation Oncology 2012 Radiation Oncology Journal Vol.30 No.1

Purpose: To evaluate the effect of common three photon energies (6-MV, 10-MV, and 15-MV) on intensity-modulated radiation therapy (IMRT) plans to treat prostate cancer patients. Materials and Methods: Twenty patients with prostate cancer treated locally to 81.0 Gy were retrospectively studied. 6-MV, 10-MV, and 15-MV IMRT plans for each patient were generated using suitable planning objectives, dose constraints, and 8-field setting. The plans were analyzed in terms of dose-volume histogram for the target coverage, dose conformity, organs at risk (OAR) sparing, and normal tissue integral dose. Results: Regardless of the energies chosen at the plans, the target coverage, conformity, and homogeneity of the plans were similar. However, there was a significant dose increase in rectal wall and femoral heads for 6-MV compared to those for 10-MV and 15-MV. The $V_{20Gy}$ of rectal wall with 6-MV, 10-MV, and 15-MV were 95.6%, 88.4%, and 89.4% while the mean dose to femoral heads were 31.7, 25.9, and 26.3 Gy, respectively. Integral doses to the normal tissues in higher energy (10-MV and 15-MV) plans were reduced by about 7%. Overall, integral doses in mid and low dose regions in 6-MV plans were increased by up to 13%. Conclusion: In this study, 10-MV prostate IMRT plans showed better OAR sparing and less integral doses than the 6-MV. The biological and clinical significance of this finding remains to be determined afterward, considering neutron dose contribution.