췌장암 MRgART시 복부가스용적 변화에 의한 선량전달오류 원인 분석

하민용,손상준,김찬용,이제희,Ha, Min Yong,Son, Sang Jun,Kim, Chan Yong,Lee, Je Hee 대한방사선치료학회 2020 대한방사선치료학회지 Vol.32 No.-

목 적: 본 연구에서는 췌장암 환자 MRgART(Magnetic Resonance-guided Adaptive Radiation Therapy)시 복부가스용적변화로 인하여 Image fusion 과정에서 생길 수 있는 조직과 가스의 전자밀도 매칭오류를 확인하고 그에 따른 선량 변화와 치료시간에 미치는 영향을 확인해 보고자 한다. 대상 및 방법: 본원에서 ViewRay MRIdian System (Viewray, USA)를 이용하여 MRgART를 시행한 췌장암 환자 중 최초 simulation시와 비교하여 복부가스용적감소가 발생한 환자를 대상으로 Initial plan과 복부가스 전자밀도를 수정한 AGC(Abdominal gas correction) plan의 PTV와 OAR선량을 비교하였고, 총4회 Adaptive 치료에서 환자의 Beam ON(%)을 확인하여 복부가스용적이 치료시간에 미치는 영향을 확인해 보았다. 결 과: Initial plan에서의 Mean, Minimum, Maximum 선량과 AGC plan의 Mean, Minimum, Maximum 선량평균값을 비교하였을 시 OAR에서는 -7~0.1%의 선량차이를 보였으며 평균 0.16% 감소하였고, PTV에서는 4.5~5.5%의 선량이 감소하였으며 평균 5.1%의 선량이 감소하였다. Adaptive치료 시 복부가스용적이 증가할수록 Beam ON(%)이 감소하였다. 결 론: Initial plan과 Adaptive plan간 복부가스용적 변화는 Adaptive plan시 전자밀도매칭 오류로 이어질 수 있으며 이는 PTV와 주변OAR의 선량분포를 변화시키므로 Adaptive plan시 영상 fusion 과정에서 가스용적을 보정한 정확한 전자밀도매칭은 필수적인 요소이다. 또한 복부가스용적이 커질수록 Beam ON(%)이 감소하여 환자의 Motion error로 인한 치료시간이 증가될 수 있다. 따라서 MRgART시에는 전자밀도매칭을 확인하고 복부가스의 가변성을 최소화 하여야 한다. Purpose: The purpose of this study is to confirm the matching of the electron density between tissue and gas due to variation of abdominal gas volume in MRgART (Magnetic Resonance-guided Adaptive Radiation Therapy) for pancreatic cancer patients, and to confirm the effect on the dose change and treatment time. Materials and Methods: We compared the PTV and OAR doses of the initial plan and the AGC(Abdominal gas correction) plans to one pancreatic cancer patient who treated with MRgART using the ViewRay MRIdian System (Viewray, USA) at this clinic. In the 4fx AGC plans, Beam ON(%) according to the patient's motion error was checked to confirm the effect of abdominal gas volume on treatment time. Results: Comparing the Initial plan with the average value of AGC plan, the dose difference was -7 to 0.1% in OAR and decreased by 0.16% on average, and in PTV, the dose decreased by 4.5% to 5.5% and decreased by 5.1% on average. In Adaptive treatment, as the abdominal gas volume increased, the Beam ON(%) decreased. Conclusion: Abdominal gas volume variation causes dose change due to inaccurate electron density matching between tissue and gas. In addition, if the abdominal gas volume increases, the Beam ON(%) decreases, and the treatment time may increase due to the motion error of the patient. Therefore, in MRgART, it is necessary to check the electron density matching and minimize the variability of the abdominal gas.

호흡조절에 따른 위전도와 심박변이도 변화 연구

하성룡 ( Song-yong Haa ),박영배 ( Young-bae Park ),양동훈 ( Dong-hoon Yang ),박영재 ( Young-jae Park ),김민용 ( Min-yong Kim ) 대한한의진단학회 2007 大韓韓醫診斷學會誌 Vol.11 No.1

Background: The change in the respiratory pattern has an influence on the change in the autonomic nervous system, which in turn has an influence on the EGG to measure a gastric activity. However, the study on the influence on the EGG parameters by respiratory control and on the correlation between the HRV and EGG through respiratory control has not been perform yet. Objective: It is to perform a series of experiments to find out how the EGG parameters are influenced by the controlled respiration and what correlation there may exist between the EGG and HRV to measure the change in the autonomic nervous system after controlled respiration. Methods: 1st Experiment: During a 15minutes` voluntary respiration, HRV was measured, and it was measured again during another 15 minutes` controlled respiration. 2nd Experiment: After an eight hours` fast, EGG was measured for a period of 30 minutes, and then after another 15 minutes` voluntary respiration, a test-meal was offered for 10 minutes and again EGG was measured. The next day, after an 8 hour`s fast, EGG was measured for 30 minutes, and after a 15 minutes` controlled respiration and offered with a test-meal for 10 minutes and then EGG was measured again for 30 minutes. Results: 1. It was observed in all the channels that the power ratio increased more after controlled respiration than after voluntary respiration. No statistical significance, however, could be observed. 2. Through controlled respiration, the HP of HRV and the power ratio of EGG Channel 4 was negatively correlated, while the LF/HF of HRV and the power ratio of EGG channel 1 & 4 was positive correlated. Such correlations as mentioned above, however, could not be observed in HRV & EGG through voluntary respiration. Conclusions: 1. It was concluded that the increase in the power of gastric contractile after controlled respiration is bigger than the increase in the power of gastric contractile after voluntary respiration. 2. It was concluded that the gastric contractile power and sympathetic activity through controlled respiration was negatively correlated, while the gastric contractile power and parasympathetic activity through controlled respiration was positively correlated

한열성향에 따른 위전도 특성 연구

하성룡 ( Song-yong Haa ),김민용 ( Min-yong Kim ),박영재 ( Young-jae Park ),박영배 ( Young-bae Park ) 대한한의진단학회 2008 大韓韓醫診斷學會誌 Vol.12 No.1

Background : In relation to a diagnosis of Korean Medicine, heat-cold is one of the most important indicators for evaluation. In spite of this importance, there has not been the study that tries to examine the change of indicators in an electrogastrography (EGG) according to the heat-cold patternization. Objective: The objective of this study is to establish the correlation between the heat-cold patternization and indicators of EGG by means of Standardized Questionnaire for Heat-Cold Patternization. Method: To conduct this study, we used the method as follows: Before conducting EGG, subjects were requested to give answers to the questionnaire which was developed by Kim. Before EGG, subjects were demanded to fast for more than 8 hours and then eat the test meal. Before eating the test meal(test meal: two slices of bread, 4oz of apple juice), EGG signals were detected for 30 minutes, and then subjects could eat the test meal for 10 minutes. After eating the test meal, EGG signals were detected for 30 minutes. Results: 1. There was a negative correlation between heat score and the power ratio of channel 1 and channel 2 of EGG. There was a positive correlation between cold score and the power ratio of channel 1 of EGG. 2. There was a positive correlation between heat score and pre-prandial gastric arrhythmia in the channel 1, 2 and 4 of EGG. There was a negative correlation between cold score and post-prandial gastric arrhythmia in the channel 1, 2 and 3 of EGG. 3. There was a negative correlation between heat score and normal pre-prandial gastric slow wave in the channel 1, 2 and 4 of EGG. There was a positive correlation between cold score and normal post-prandial gastric slow wave in the channel 3 of EGG. Conclusions: From the results above, we could conclude as follows: Indicators of EGG and cold score presented a positive correlation, and heat score displayed a negative correlation. As a result, to apply EGG to a diagnosis of functional indigestion, the application of EGG to subjects who have heat patternization would increase the reliability of a diagnosis.

위전원(胃電圓) 검사(檢査)의 최근(最近) 연구(硏究) 동향(動向)에 관한 문헌적(文獻的) 고찰(考察) - 한의학적 활용을 위하여

하성룡 ( Song-yong Haa ),김민용 ( Min-yong Kim ),박영재 ( Young-jae Park ),박영배 ( Young-bae Park ) 대한한의진단학회 2006 大韓韓醫診斷學會誌 Vol.10 No.2

Objective: To review the method, parameters, system of electrogastrography and to study its oriental medical application. Method: We investigate the research results through internet search engines such as Pubmed, China National Knowledge Infrastructure. Conclusion: Electrogastrography is believed to be of great use to the verification of treatment effect of herbal medicine that is used in internal medicine and neuropsychiatry, along with the objectification and quantification of diagnosis of oriental medicine related to gastric peristalsis and balance of autonomic nervous system. I would therefore like to conclude that there should be continued study and active application of electrogastrography in the wide variety of oriental medicine.

안와 주변 방사선 치료 시 수정체 피폭선량 감소를 위한 2차 차폐의 유용성 평가

곽용국,홍순기,하민용,박장필,유숙현,조웅,Kwak, Yong Kuk,Hong, Sun Gi,Ha, Min Yong,Park, Jang Pil,Yoo, Sook Hyun,Cho, Woong 대한방사선치료학회 2015 대한방사선치료학회지 Vol.27 No.1

목 적 : 안와 주변 방사선 치료 시 수정체 피폭선량감소를 위하여 사용된 2차 차폐 block의 유용성을 알아보고자 한다. 대상 및 방법 : Human phantom(Alderson Rando Phantom, The Phantom Laboratory, USA)을 사용하여 CT(Somatom Definition AS, Siemens, Germany) 모의촬영 후 전산화치료계획시스템(Pinnacle, PHILIPS, USA)을 통해 실제 치료와 유사한 IMRT치료계획을 실시하였다. 2차 차폐를 위하여 두께 3mm 지름 25 mm의 납판과 3 mm tungsten eye-shield block(Extra small size, Radiation Products Design, Inc, USA)를 사용하였으며, TPS(Treatment Planning System) 상의 lens dose와 모의치료 상의 lens dose를 OSLD로 측정 비교하였다. 또한, 5 cm 두께의 acrylic phantom에 동일한 조건의 2차 차폐물인 3 mm 납판과 tungsten eye-shield block을 사용하여 200 MU(6 MV, SPD(Source to Phantom Distance)=100 cm, $F{\cdot}S\;5{\times}5cm$)를 조사 및 측정하였으며, 조사야 밖의 누설선 및 투과방사선 영향을 제한시키고자 8 cm 납블럭(O.S.B: Outside Scatter Block)을 적용하여 위와 동일한 실험을 시행하였다. 조사야로부터 1 cm 이격하여 phantom 끝 옆면에 OSLD(Optically Stimulated Luminescence Dosimeter)를 부착하였고, eyelid의 두께에 해당하는 bolus 3 mm를 적용하였다. 결 과 : human phantom을 이용하여 IMRT 치료계획 상의 Lens dose와 실 측정치는 각각 315.9, 216.7 cGy가 측정되었고, 3 mm 납판과 tungsten eye-shield block으로 2차 차폐 후 각각 234.3, 224.1 cGy가 측정되었다. acrylic phantom을 이용한 실험 결과는 no block, 3 mm 납판, tungsten eye-shield block을 사용했을 때 5.24, 5.42, 5.39 cGy가 측정되었으며, 조사야 밖에 O.S.B를 적용하여 no block, 3 mm 납판, tungsten eye-shield block을 실험한 결과 각각 1.79, 2.00, 2.02 cGy가 측정되었다. 결 론 : 광자선 조사 시 critical organ을 보호하기 위하여 2차 차폐를 적용할 시에는 field 외부일지라도 헤드 누설방사선 및 collimator & MLC 투과방사선이 존재하므로 치료부위와 beam 방향에 따라 금속과 같은 높은 원자번호의 차폐물질이 critical organ근처에 있다면 선량 증가의 원인이 될 수 있다는 사실을 알 수 있었다. 따라서 피폭선량 감소를 위한 2차 차폐의 시도는 분명 의미가 있었으나 미 검증된 시도는 오히려 역효과를 가져올 수 있다는 사실을 인지하여 QA를 통해 목적에 부합하는 결과가 나오는지를 사전에 알아보아야 할 것이다. Purpose : This study presents the usefulness assessment of secondary shield for the lens exposure dose reduction during radiation treatment of peripheral orbit. Materials and Methods : We accomplished IMRT treatment plan similar with a real one through the computed treatment planning system after CT simulation using human phantom. For the secondary shield, we used Pb plate (thickness 3mm, diameter 25mm) and 3 mm tungsten eye-shield block. And we compared lens dose using OSLD between on TPS and on simulation. Also, we irradiated 200 MU(6 MV, SPD(Source to Phantom Distance)=100 cm, $F{\cdot}S\;5{\times}5cm$) on a 5cm acrylic phantom using the secondary shielding material of same condition, 3mm Pb and tungsten eye-shield block. And we carried out the same experiment using 8cm Pb block to limit effect of leakage & transmitted radiation out of irradiation field. We attached OSLD with a 1cm away from the field at the side of phantom and applied a 3mm bolus equivalent to the thickness of eyelid. Results : Using human phantom, the Lens dose on IMRT treatment plan is 315.9cGy and the real measurement value is 216.7cGy. And after secondary shield using 3mm Pb plate and tungsten eye-shield block, each lens dose is 234.3, 224.1 cGy. The result of a experiment using acrylic phantom, each value is 5.24, 5.42 and 5.39 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Applying O.S.B out of the field, each value is 1.79, 2.00 and 2.02 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Conclusion : When secondary shielding material is used to protect critical organ while irradiating photon, high atomic number material (like metal) that is near by critical organ can be cause of dose increase according to treatment region and beam direction because head leakage and collimator & MLC transmitted radiation are exist even if it's out of the field. The attempt of secondary shield for the decrease of exposure dose was meaningful, but untested attempt can have a reverse effect. So, a preliminary inspection through Q.A must be necessary.

FeRh2X4(X=O, Se, S, Te)의 자기적 성질에 관한 연구

金哲聖,沈仁輔,河敏容, 朴宰潤 국민대학교 1991 기초과학연구소 논문집 Vol.9 No.-

불균질부 방사선치료 시 계획 선량의 정확성 평가

김찬용,이제희,곽용국,하민용,Kim, Chan Yong,Lee, Jae Hee,Kwak, Yong Kook,Ha, Min Yong 대한방사선치료학회 2013 대한방사선치료학회지 Vol.25 No.2

목 적: 불균질부를 포함하고 있는 치료부위의 치료계획 시 불균질 경계면에서의 TPS상 선량분포와 phantom을 이용하여 측정된 실제 선량분포를 비교하여 그 차이를 알아보고자 한다. 대상 및 방법: 4 cm 두께의 solid water phantom 사이에 폐와 유사한 밀도를 가진 8 cm 두께의 cork (density: 0.23 $g/cm^2$)를 위치시켜 phantom을 제작하여 CT 영상을 획득하였으며, 본원에서 사용하고 있는 Pinnacle 치료계획 시스템의 Collapsed-cone(CC) convolution 선량계산 알고리즘을 이용하여 6/15 MV 광자선으로 치료 계획된 선량분포와 실제 phantom에 EBT2 필름을 삽입해 측정한 선량을 비교 평가하였다. 또한 실제 폐암 환자와 유사한 치료계획을 비교하기 위해 Phantom 내부에 치료하고자 하는 종양부위(target volume)로 가정한 파라핀($3{\times}3{\times}3$ cm)을 Location "A" (일반조직과 떨어져있는 가상의 종양: 섬모델)와 Location "B" (일반조직과 붙어있는 가상의 종양: 반도모델)에 삽입하여 CT scan 후 치료계획을 시행하였다. 선량계획과 동일한 조건으로 Phantom을 set-up 후 Phantom의 paraffin target volume 경계면 A (Ant방향), B (Rt방향), C (Post 방향) point에 필름을 삽입하고 방사선을 조사하여 측정된 선량을 TPS선량과 비교평가 하였다. 결 과: 불균질 phantom을 이용한 계획선량과 측정선량과의 차이는 solid water와 cork 경계면을 제외한 부분에서 선량차이가 크지 않았지만 밀도가 급격히 변화하는 첫 번째 구간과 두 번째 구간에서 -5.4%~-12.6%의 선량감소를 보였다. 또한 paraffin target을 삽입한 실험에서는 Location "A"의 경우 실제 측정선량이 A, B, C point에서 각각 -2.5~-4.7%, -2.3~-2.8%, -4.5~-8.8%의 낮은 선량을 나타냈으며, Location "B"의 경우에도 A, B, C point에서 각각 0.08~5.27%, -3.17~-4.74%, -7.86~-11.56%의 선량 차이를 나타내었다. 결 론: 이번 연구의 결과 불균질부 내에서의 치료계획 시스템의 계획된 선량과 실제 측정된 선량에 오차의 가능성이 확인되었다. 급속도로 발전하고 있는 방사선 치료기술과 그만큼 정밀함을 요하는 치료계획 시 이러한 가능성에 대해 인지하고 선량검증에 대한 여러 방법들을 연구하고 개발하는 것이 치료의 발전과 필수적으로 동반되어야 할 것이며 본원에서도 이번 연구를 통해 치료계획 시 발생할 수 있는 변수에 대해서 더 주의 깊게 판단하고 적용할 수 있을 것으로 사료된다. Purpose: We are to find out the difference of calculated dose of treatment planning system (TPS) and measured dose in case of inhomogeneous organ structure. Materials and Methods: Inhomogeneous phantom is made with solid water phantom and cork plate. CT image of inhomogeneous phantom is acquired. Treatment plan is made with TPS (Pinnacle3 9.2. Royal Philips Electronics, Netherlands) and calculated dose of point of interest is acquired. Treatment plan was delivered in the inhomogeneous phantom by ARTISTE (Siemens AG, Germany) measured dose of each point of interest is obtained with Gafchromic EBT2 film (International Specialty Products, US) in the gap between solid water phantom or cork plate. To simulate lung cancer radiation treatment, artificial tumor target of paraffin is inserted in the cork volume of inhomogeneous phantom. Calculated dose and measured dose are acquired as above. Results: In case of inhomogeneous phantom experiment, dose difference of calculated dose and measured dose is about -8.5% at solid water phantom-cork gap and about -7% lower in measured dose at cork-solid water phantom gap. In case of inhomogeneous phantom inserted paraffin target experiment, dose difference is about 5% lower in measured dose at cork-paraffin gap. There is no significant difference at same material gap in both experiments. Conclusion: Radiation dose at the gap between two organs with different electron density is significantly lower than calculated dose with TPS. Therefore, we must be aware of dose calculation error in TPS and great care is suggested in case of radiation treatment planning on inhomogeneous organ structure.

酸化鐵의 磁氣的 性質에 관한 硏究

金哲聖,沈仁輔,金大榮, 河敏容, 조철구 國民大學校 기초과학연구소 1990 기초과학논총 Vol.8 No.1

Zn-Ge Ferrite의 자기적 성질에 관한 연구

김철성,이무안,고흥문, 이운화, 하민용 국민대학교 1992 기초과학연구소 논문집 Vol.10 No.-

Mossbauer Study of Co0.3Fe0.7Cr₂S₄

김철성(C. S. Kim),하민용(M. Y. Ha),이운화(W. H. Lee),윤성로(S. R. Yoon),서정철(J. C. Sur) 한국자기학회 1992 韓國磁氣學會誌 Vol.2 No.3

Co_(0.3)Fe_(0.7)Cr₂S₄ has been studied by Mossbauer spectroscopy and X-ray diffraction, The crystal structure is found to be a cubic spinel with the lattice parameter α。=9.967 Å. Mossbauer spectra have been collected over the temperature range 12 K ~ 300 K. The absence of quadrupole splitting above the Neel temperature T_N indicates that iron ions occupy only the tetrahedral (A) sites, The isomer shift indicates that the charge state of a Fe ion is ferrous in character. It is notable that as the temperature decreases below T_N=184 K, both quadrupole splitting and asymmetrical line broadening appear and increase with decreasing temperature, suggesting the appearence of a dynamic Jahn-Teller distortion. The magnetic hyperfine field and quadrupole splitting at 12 K are found to be 193 kOe and 1.10 ㎜/s, respectively, Debye temperature is found to be 218 K.