Customer Acceptance Procedure for Clinac (21EX-Platinum)

홍동기,이우석,권경태,박광호,김정만,Hong, Dong-Ki,Lee, Woo-Seok,Kwon, Kyung-Tae,Park, Kwang-Ho,Kim, Chung-Man 대한방사선치료학회 2004 大韓放射線治療技術學會誌 Vol.16 No.2

목적 : 환자의 치료에 있어서 정확한 장비의 설치와 성능 평가는 치료의 질을 향상시키는데 중요한 요소라고 할 수 있으며 사용자가 장비의 특성과 사용 방법을 숙달하고 업무를 수행하는 것이 매우 중요하다고 생각한다. 그러므로 방사선 치료기를 설치하고 방사선 치료를 하기 전에 사용자가 직접 장비의 설치와 성능 평가에 참여하고 특성을 파악하여 이해하는 것이 필요하다. 본 연구에서는 CAP의 과정과 성능 평가결과를 소개하고자 한다. 대상 및 방법 : 선형가속기 21EX(varian, USA)를 대상으로 설치 시부터 성능 검사까지 전 과정을 평가하였고 성능평가는 크게 radiation survey, mechanical test, radiation isocenter test, beam performance, dosimetry, enhanced dynamic wedge로 구분하여 X-omat film(kodark), 선량 측정 장비(multidata, densitometer, electrometa)를 이용하여 실시하였다. 또한 선형가속기에 부착된 MLC(millenium, 120leaf)와 EPID(portal vision)의 성능 평가는 별도로 실시하였다. 결과 : Survey meter를 이용하여 측정한 leakage는 허용 범위 이하의 선량이 검출되었고 mechanical test에서 collimator, gantey, couch rotation은 1mm 이하였고 육안으로 평가한 angle은 digital이 ${\pm}1^{\circ}$이내에 mechanical은 ${\pm}5^{\circ}$이내였다. 또한 light field와 cross-hair의 직선성 검사도 1mm이내로 평가되었다. (A)symmetrical jaw field는 upper/lower 모두 ${\pm}0.5mm$이내였다. X-omat film을 이용한 radiation isocenter test는 1mm 이하였고 light field와 radiation field 의 일치성 검사는 ${\pm}1mm$ 이내였으며 선량 측정 장비를 이용하여 측정한 $\%DD$는 photon energy는 모두 ${\pm}1\%$ 이내로 electron energy는 $90\%,\;80\%,\;50\%,\;30\%$를 측정한 결과 허용 범위 내에서 평가되었다. photon 과 electron energy의 flateness는 각각 $2.3\%$(기준 $3\%$)이내, $3\%$(기준 $4.5\%$)이내이고 symmetry는 $0.45\%$(기준 $2\%$), $0.3\%$(기준 $2\%$)이내에서 평가 할 수 있었다. 그리고 dosimetry test는 sort term, MU setting, rep rate, dose rate accuracy를 photon과 electron energy 별로 MU와 gantry angle을 바꿔가면서 측정한 결과 허용범위 오차이내에 포함되는 것을 확인 할 수 있었다. EPID(portal vision)의 Exact-Arm의 기계적인 검사는 vertical, lateral, longitudinal은 허용범위 내에서 동작했으며 명암과 해상도 검사도 05.mm의 니크롬선이 선명하게 나타났으며 phantom의 음영도 뚜렷하게 나타났다. Multileaf collimator(MLC)검사는 leaf이 isocenter의 중심에 정확하게 배열되었으며 재현성 검사도 정상적으로 동작하였다. 결론 : Clinac 21EX 장치의 customer acceptance를 통해서 향후의 환자의 치료를 하는데 있어 장치의 안정성을 확인 할 수 있었으며 치료 전의 선형가속기와 주변장치의 특성을 파악 할 수 있어서 장비 사용에 있어서 어려움을 감소시킬 수 있으리라고 생각된다. 또한 사용자가 적극적으로 참여함으로써 앞으로 환자를 치료하는데 있어서도 많은 도움이 되리라 생각한다. Purpose : For qualify improvement in radiotherapy, it is important to set up and evaluate equipment (linac) accurately. In addition, technicians are needed to be fully aware of the equipment's detailed quality and its manual. Therefore, the result of ATP is evaluated and introduced, in order that the technicians are skilled by participating in quality assurance (QA) and understanding the quality of the equipment before clinical use. Method and Material : QA for LINAC 21EX (Varian, US) was done with suppliers its procedure was divided into radiation survey, mechanical test, radiation isocenter test, bean performance, dosimetry, and enhanced dynamic wedge and using X-omat film (Kodak), multidata, densitometer, and electrometer. QA of MLC (Millennium, 120 leaf) attached to LINAC and EPID (Portal vision) were done separately. Result : The leakage dose by survey meter was below the tolerance. In mechanical test, collimater, gantry, and couch rotation were less than 1mm, and the angles were ${\pm}0.1^{\circ}$ for digital and ${\pm}0.5^{\circ}$ for mechanical. The alignment test of the light field and crosshair were evaluated less than 1mm. The (a)symmetrical jaw field was less than ${\pm}0.5mm$. The radiation isocenter test using X-mat film was less than 1mm. The consistency of light field and radiation field was less than ${\pm}0.1mm$. PDD for photon energy was less than ${\pm}1\%$ and for electron energy of $90\%,\;80\%,\;50\%,\;and\;30\%$ were evaluated within the tolerance. Flatness for photon and electron energy was evaluated $2.3\%$ (tolerance $3\%$) and $3\%$ (tolerance $4.5\%$), respectively, and symmetry was $0.45\%$ (tolerance $2\%$) and $0.3\%$ (tolerance $2\%$), respectively. Dosimetry test for short term, MU setting, rep rate, and dose rate accuracy of photon and electron energy was within the tolerance depending on energy, MU, and gantry angle. Conclusion : Accuracy and safety for clinical use of Clinac 21EX was verified through customer acceptance procedure and the quality of the equipment was found out. These can reduce the difficulties in using the equipment. Furthermore, it is useful for clinically treatment of patients by technicians' active participations.

두경부암 환자 치료시 3차원 보상체의 임상 적용에 대한 고찰

홍동기,이정우,이두현,박광호,김정만,Hong, Dong-Ki,Lee, Jeong-Woo,Lee, Koo-Hyun,Park, Kwang-Ho,Kim, Jeong-Man 대한방사선치료학회 1997 大韓放射線治療技術學會誌 Vol.9 No.1

The goal of radiation treatment planning is to deliver the dose to the patient within $5\%$ of that prescribed. We have often encountered the situation that the area which have not only several irregular contours but also tissue heterogeneities should be treated. With conventional devices such as wedges, missing tissue compensator. there are some limitations to achieve the uniform dose distribution in treatment volume. The use of CT simulator, 3-D planning system, computer-controlled milling machine enables it to deliver the dose uniformally. This report includes the whole procedure which have patient data acquisition 3D planning, computer-controlled milling, performance verification of 3D compensator, and TLD evaluation. We applied it for the treatment of head and heck cancer only. In Spite of the irregular contour and different electron density of tessue, we have achieved the uniformity of the dose distribution within ${\pm}3\%$ relatively. Although there are some problems which are not only verification of performance but uncertainties of using the new treatment device, we believe that the improvement of dosimetry will eliminate the uncertainties of that application. so the other lesions besides head and neck can will be ale to use the 3D compensator to achieve the dose uniformity

기화주제(企畵主題)(민사절차법의 문제점과 그 해결방안 ; 부실등기 방지를 위한 등기신청절차의 개선방안 -등기원인증서의 공증제와 자격대리인의 본인확인의무를 중심으로-

홍동기 ( Dong Ki Hong ) 경성대학교 법학연구소 2013 경성법학 Vol.22 No.-

Real estate registration is a national level notarization behavior that aims to protect citizens`` private properties and to pursue after stable transaction by accurately notifying the changes pertaining ti the relationship of real estate rights. In other words, real estate registration is a means for posting up the real right in an official manner. Thus, if there is confusion or defect when it comes to the registration, this I bound to cause immense confusion regarding citizens`` real right. Accordingly, registration system aims to contribute to the stability and effective control of real estate transactions by posting up the changes of the actual real right accurately and rapidly. Moreover. Korea takes on the orientation pertaining to the requirements for validity(formalism) when it comes to real estate real right change. Thus, in order for the registration system to fulfill its inherent role which is real estate transaction safety, it is required that the real estate``s actual state should be reflecter accurately on the register, and it is also required that the process of change when it comes to the relationship of rights that are registered for a certain real estate is listed on the register accurately without omission. Accordingly, in order to realize the deals of the registration system which are the accurate official posting of real right change and protection of transaction safety, it is necessary to prevent poor registration to ensure accurate official posting of the real right change above anything. Meanwhile, it is also necessary to pursue after the measures to ensure transaction safety by laying down the means for handing poor registration legally and by developing the system for the protection of the entrusting party against poor registration with the assumption that poor registration cannot be completely eliminated despite these efforts. The ultimate goal of the registration system of the entrusting day is to carry out official posting accurately and promptly while ensuring harmony between the real estate transaction safety and effective control. Until recently, discussions were being held about the following in Korea in order to prevent poor registration and to increase registration``s reliability level; adoption of the notarization system for the deed of grounds for registration. securing of registration officials`` actual right to review. unification of general register ledger, registration compulsory, and strengthening of the self authentication procedure for the agent applying fir registration. There is no doubt that all these systems can serve as a means to improve registration``s reliability. However, even when these systems as a means to improve registration``s reliability. However, even when these systems are measures that can prevent poor registration and? increase registration``s reliability level on a logical level. it is necessary to factor in the reality of Korea such as the current status concerning application for registration and progress on the operation of the registration system before making the decision on whether to adopt them or not. If not. adoption of a certain system a be realize the goal which was intended in the beginning due to the realistic limitations. Instead, this system could in fact increase burden on the citizens or impede promptness of the registration procedure. Meanwhile, even when the legislation and realities of each of the advanced nations of the West are examined, it appear as if poor registration cannot be eliminated despite the adoption of numerous systems and despite the extensive effort made to increase registration``s reliability level. This demonstrates that there is need to pursue after the measures to protect the party that trusts poor registration and formed relationship of transaction while making the effort to prevent poor registration. To these, this research reviewed all these system level measures which were being discussed in the past to prevent poor registration by utilizing the experiences of the`` working level registration official by focusing on practical value and feasibility of adopting. Meanwhile, this research clearly disclosed all the measures for the rational handing of poor registration if it occurs and for the protection of entrusting party through the interpretation of the existing laws. Meanwhile, this research seeks to contribute to the development of the registration system that suits our reality by unfolding the legislation for the recognition of registration``s public confidence. Towards this end, there is a need to carry out the following. CD In relation to the question of adopting the notarization system for the deed of grounds for registration. it is important to note that the share of poor registration that is related to the notarization of the deed of grounds for registration is not very high. Moreover, even when the deed of grounds for registration notarization system is adopted. the effect on the prevention of poor registration may not be high when compared to the additional social and economic costs that citizens have to assume. Given all these., it may be possible to complement through the strengthening of the qualification agent``s self authentication procedure sunce an agent is in charge of applying for registration in most cases instead of merely relying on the adoption of deed of grounds for registration notarization system. (2)In order to adopt the system in which registration official carries out the review in actuality. in a complete manner. it is necessary to factor in the reality in which the number of registration officials is very short. compared to the number of registration applications. Thus. it is necessary to review the possibility of adopting the system in parts for some of the registration, ® Moreover. it is necessary to alleviate mis match for marking of real estate by linking the register and general ledger via IT system. @ As for the registration regarding marking. there is a need to modify and to complement the system level measures to suit our reality before adopting so that they. would including measures to prevent poor registration by making registration compulsory. Moreover, the following measures are needed to protect the entrusting party of the poor registration resulting despite this and to pursue after transaction safety. CDAs for the present time when the registration``s public confidence is not recognized, it is necessary to protect the entrusting party of the poor registration in case there is a need to withstand the sacrifice of the genuine right holder by providing the root causes of poor registration through the rational interpretation of the existing laws. (2) Ultimately. it is necessary to recognize public confidence when it comes to the registration to review legislative solution with the prerequisite of pursuing after systematic measures to third party``s safety.

직물전극을 이용한 손목형 ECG 측정 장치에 관한 연구

홍동기(Dong-Ki Hong),김경호(Kyung-Ho Kim) 대한전기학회 2014 정보 및 제어 심포지엄 논문집 Vol.2014 No.4

직물전극을 이용한 심전도 측정에 관한 연구

홍동기(Dong-Ki Hong),정인복(In-Bok Jung),김경호(Kyung-Ho Kim) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.7

Hepatoprotective Effect of Alnus japonica and Portulaca oleracea Complex on Alcohol-induced Liver Injury Mice Models by Anti-oxidation Activity

홍동기(Dong ki Hong),박수동(Soodong Park),김주연(Jooyun Kim),심재정(Jaejung Shim),이정률(Junglyoul Lee) 한국자원식물학회 2023 한국자원식물학회지 Vol.36 No.3

Analytical Anisotropic Algorithm을 사용한 폐암 치료 시 MU 검증 프로그램 적용에 관한 고찰

김종민,김대섭,홍동기,백금문,곽정원,Kim, Jong-Min,Kim, Dae-Sup,Hong, Dong-Ki,Back, Geum-Mun,Kwak, Jung-Won 대한방사선치료학회 2012 대한방사선치료학회지 Vol.24 No.1

목 적: Analytical Anisotropic Algorithm (AAA)을 사용하여 계산된 폐 부위 방사선치료계획은 Pencil Beam Convolution (PBC) Algorithm 기반의 MU 검증 프로그램을 이용하였을 때 MU의 오차가 발생하여 MU 검증 프로그램 사용에 어려움이 있다. 본원에서는 AAA를 사용하여 계산된 치료계획을 검증할 방법에 대하여 연구하였다. 대상 및 방법: Eclipse treatment planning system (Version 8.9, Varian, USA)을 사용하여 폐 부위 정위적체부방사선치료(Stereotactic Body Radiation Therapy, SBRT) 7건에서의 총 57개 조사야(Field) 각각에 대하여 선량계산 알고리즘으로 PBC와 AAA를 사용하여 계산하였다. 수립된 치료계획의 MU를 자체 개발하여 사용 중인 MU 검증 프로그램의 MU와 비교 분석하였다. PBC 알고리즘과 AAA에서 발생한 오차에 영향을 미칠 수 있는 조사야크기(Field size), 방사선이 폐 조직을 통과한 거리, 방사선이 종양 조직을 통과한 거리, 유효깊이(Effective depth) 등 4가지 변수에 대하여 오차와의 상관관계를 상용 프로그램을 이용하여 분석하였다. 결 과: PBC 알고리즘의 오차는 $0.2{\pm}1.0%$로 나타났으며 AAA의 오차는 $3.5{\pm}2.8%$로 나타났다. 또한, 오차에 영향을 미칠 수 있는 4가지 변수에 대해 분석한 결과, 방사선이 폐 조직을 통과한 거리와 MU의 오차와의 관계에서 상관계수 0.648 (P=0.000)로 유의하게 증가하였고, ${\Delta}_{AAA}$=L.P 0.00903+0.02048이라는 MU 보정인자를 산출해 낼 수 있었으며 MU 보정인자를 MU 검증 프로그램에 적용한 결과, 적용 전 $3.5{\pm}2.8%$의 오차는 $0.4{\pm}2.0%$ 이내로 줄어들었다. 결 론: 본 연구에서는 방사선이 폐 조직을 통과한 거리가 커질수록 MU 검증 프로그램과의 오차가 커짐을 알아냈으며, MU보정인자라는 간단한 방법을 통해 AAA 알고리즘의 MU를 검증할 수 있게 되었다. Purpose: There was a problem with using MU verification programs for the reasons that there were errors of MU when using MU verification programs based on Pencil Beam Convolution (PBC) Algorithm with radiation treatment plans around lung using Analytical Anisotropic Algorithm (AAA). On this study, we studied the methods that can verify the calculated treatment plans using AAA. Materials and Methods: Using Eclipse treatment planning system (Version 8.9, Varian, USA), for each 57 fields of 7 cases of Lung Stereotactic Body Radiation Therapy (SBRT), we have calculated using PBC and AAA with dose calculation algorithm. By developing MU of established plans, we compared and analyzed with MU of manual calculation programs. We have analyzed relationship between errors and 4 variables such as field size, lung path distance of radiation, Tumor path distance of radiation, effective depth that can affect on errors created from PBC algorithm and AAA using commonly used programs. Results: Errors of PBC algorithm have showned $0.2{\pm}1.0%$ and errors of AAA have showned $3.5{\pm}2.8%$. Moreover, as a result of analyzing 4 variables that can affect on errors, relationship in errors between lung path distance and MU, connection coefficient 0.648 (P=0.000) has been increased and we could calculate MU correction factor that is A.E=L.P 0.00903+0.02048 and as a result of replying for manual calculation program, errors of $3.5{\pm}2.8%$ before the application has been decreased within $0.4{\pm}2.0%$. Conclusion: On this study, we have learned that errors from manual calculation program have been increased as lung path distance of radiation increases and we could verified MU of AAA with a simple method that is called MU correction factor.

Image Viewer System의 개발 및 적용에 관한 고찰

양오남,서인기,홍동기,권경태,Yang, Oh-Nam,Seo, In-Ki,Hong, Dong-Ki,Kwon, Kyeong-Tae 대한방사선치료학회 2006 대한방사선치료학회지 Vol.18 No.2

Purpose: The number of patients receiving radiotherapy has increased every year and will keep increasing in the future. Therefore, the technique of radiotherapy is developing from day to day, as a result of it, the quantities of image and data used for radiotherapy are also considerably increasing. Therefore, there have been many difficulties in storing, keeping and managing them. Then, we developed and applied this system for improving complicated work process as well as solving these problems with the collaboration Medical Information Team. Materials and Methods: We exported its image at R & V (Record and Verify: Varis vision, Varian, USA) system and planning system after giving some code to be able to access from management system(RO) for department of radiation oncology to PACS. And, we programmed their information by using necessary information among many information included in DICOM head. Results: All images and data generated by our working environment (Simulation CT, L-gram image and internal body structure, DRR, does distribution )were realized at PACS and it became to be possible for clear image to be printed from any computer in department of radiation oncology. Conclusion: It was inevitable to use film during radiotherapy for patients in the past, however, due to the development of this system, film-less system became to be possible. Therefore, the darkroom space and its management cost in relation to the development process disappeared and it became to be unnecessary for spending tangible and intangible financial expense including human resources, time needed for finding film storing space and film and purchasing separate storing equipment for storing images. Finally, we think this system would be very helpful to handle ail complicated processes for radiotherapy and increasing efficiency of overall working conditions.

PTT를 활용한 이완혈압 추정에 관한 기초연구

이진욱(Jin-Wook Lee),홍동기(Dong-Ki Hong),김희훈(Hee-Hun Kim),김경호(Kyung-Ho Kim) 대한전기학회 2015 대한전기학회 학술대회 논문집 Vol.2015 No.2

본 논문에서는 ECG(Electrocardiography) 와 PPG(Photoplethysmogram)의 주요 peak를 이용하여 상호간의 시간차를 이용하여 PTT(Pulse Transit Time)를 측정하였다. PTT를 이용한 수축기 혈압의 추정이 아닌 PTT를 이용한 이완기 혈압 추정에 대하여 상관관계를 분석하고자 기초연구를 하였다. ECG와 PPG를 측정할 수 있는 디바이스를 설계를 하여 ECG의 R-peak와 S-peak, PPG의 P-peak와 S-peak 정보를 취득하였고, 취득한 각 각의 ECG peak와 PPG peak의 시간차를 이용하여 다양한 PTT를 구하였다. 구해진 PTT를 이용하여 회귀분석을 통하여 PTT와 이완혈압의 상관관계를 확인하고, 분산 그래프를 통하여 혈압추정공식을 도출을 해 측정한 혈압과 비교분석을 하려고 하였다. 실험은 총 15명의 피 실험자를 대상으로 시중에 있는 커프식 방식의 혈압계와 제작한 생체신호 수집 장치를 이용하여 ECG와 PPG간의 PTT를 동시 측정한 후 분석한 결과 ECG와 PPG의 peak중 PPG의 S-peak가 이완혈압과의 상관관계가 있다는 것을 알아내었다. 이후 혈압추정공식을 도출한 후 측정혈압과 비교를 한 결과 PTT를 이용하여 이완혈압을 추정할 수 있는 가능성을 확인 하였다.

영상 유도 방사선치료 시 Fiducial Marker의 Artifact에 관한 연구

김종민,김대섭,백금문,강태영,홍동기,윤화룡,권경태,Kim, Jong-Min,Kim, Dae-Sup,Back, Geum-Mun,Kang, Tae-Yeong,Hong, Dong-Ki,Yun, Hwa-Yong,Kwon, Kyeong-Tae 대한방사선치료학회 2010 대한방사선치료학회지 Vol.22 No.1

Purpose: The effect of artifact was analyzed, which occurs from fiducial marker during the liver Image Guided Radiation Therapy (IGRT) using the fiducial marker. Materials and Methods: The size of artifact of fixed fiducial marker and length of mobile fiducial marker locus were measured using the On-Board Imager system (OBI) and CT simulator, and 2D-2D matching and 3D-3D matching were carried out, respectively, and at this time, the coordinates transition value of couch was analyzed. Results: The measurement of fixed fiducial marker artifact size indicated CT 4.90, 8.10, 12.90, 19.70 mm and OBI 5.60, 10.60, 14.70, 29.40 mm based on the reference CT slice thickness of 1.25, 2.50, 5.00, and 10.00 mm. Meanwhile, the measurement of mobile fiducial marker locus length indicated CT 42.00, 43.10, 46.50 mm, and OBI 43.40, 46.00, 49.30 mm. The coordinates transition of 1.00, 2.00, and 8.00 mm occurred between 2D-2D matching and 3D-3D matching. Conclusion: It was confirmed that the therapy error increased during IGRT due to the influence of artifact when CT slice thickness increased. Thus, it may be desirable to acquire the image less than 2.50 mm in slice thickness when IGRT is implemented using the fiducial marker.