두경부암 세기변조방사선치료 계획 시 선량율 변화가 이하선에 미치는 영향

홍주완,정윤주,원희수,장남준,최지훈,석진용,Hong, Joo-Wan,Jeong, Yun-Ju,Won, Hui-Su,Chang, Nam-Jun,Choi, Ji-Hun,Seok, Jin-Yong 대한방사선치료학회 2010 대한방사선치료학회지 Vol.22 No.2

Purpose: There are various beam parameter in intensity modulated radiation therapy (IMRT). The aim of this study is to investigate how various dose rate affect the parotid in treatment plan of IMRT. Materials and Methods: The study was performed on 10 nasopharyngeal carcinoma patients who have undergone IMRT. CT images were scanned 3 mm of thickness in the same condition and the treatment plan was performed by Eclipse (Ver.7.1, Varian, Palo Alto, USA). The parameters for planning used 6 MV energy and 8 beams under the same dose volume constraint. The variation of dose rates were used 300, 400, 500 MU/min. The mean dose of both parotid was accessed from the calculated planning among the 10 patients. The mean dose of parotid was verificated by 2D diode array (Mapcheck from Sun Nuclear Corporation, Melbourne, Florida). Also, Total monitor unit (MU) and beam-on time was analysed. Results: According to the dose rate, the mean dose of parotid was increased by 0.8%, 2.0% each, when dose rate was changed from 300 MU/min to 400, 500 MU/min, moreover Total MU was increased by 5.4% and 10.6% each. There was also a dose upward trend in the dose measurement of parotid by 2D diode array. However, beam - on time difference of 1~2 minutes was no signigicant in the dose rate increases. Conclusion: From this study, when the dose rates increase, there was a signigicant increase of Total MU and the parotid dose accordingly, however the shortened treatment time was not significant. Hence, it is considered that there is a significant decrease of late side effect in parotid radiation therapy, if the precise dose rate in IMRT is used.

방사선 흡수선량 보정위한 대기보정계수 산출 장치 개발

홍주완,박철수,안우상,서정민,최재혁,원희수 한국자기학회 2017 한국자기학회 학술연구발표회 논문개요집 Vol.2017 No.5

Constructing a Device for Calculating the Atmospheric Correction Factor for the Calibration the Radiation-Absorbed Dose in Radiotherapy

홍주완,이진혁,안재억,유동수,허영철 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.3

The purpose of this study was to measure the air temperature and the air pressure, develop an atmospheric correction factor calculation device (ACFCD), and utilize it. Because the radiation dose varies with the temperature, pressure, and humidity, is essential calibrating doses after calculating the atmospheric correction factor. In this study, we constructed an ACFCD by using a micro controller, an air thermometer, and an air pressure sensor. We measured the temperature and the air pressure in nine different spaces and confirmed the changes in the factors. We obtained the measured data as comma-separated-values files, and we created a Microsoft Excel macro for the analysis to calculate the average temperature, pressure, and atmospheric correction factor; we determined trends by using graphs. As a result of the performance evaluation, we confirmed that the space temperature and the air pressure measurement were the same (p > 0.05). In addition, we confirmed that the micro controller unit measured the heating, which we observed to be 3.9 ◦ C. The ACFCD that we developed in this study confirmed the possibility of replacing existing air thermometers and barometers and can contribute to improving work efficiency. In addition, in light of the basic concept of the ACFCD, we consider that the device will be useful for ensuring safe, accurate use of radiation once it is made more practical through additional studies.

고전압 전기 자극의 부종 감소 효과

홍주완,김연정,김철용,안덕현 한국전문물리치료학회 1994 한국전문물리치료학회지 Vol.1 No.1

왕거머리말의 인체 암세포에 대한 세포독성 효과

홍주완(Joo Wan Hong),정명은(Myung Eun Jung),이정임(Jung Im Lee),김호준(Hojun Kim),장재수(Jae-Soo Chang),서영완(Youngwan Seo) 한국생물공학회 2012 KSBB Journal Vol.27 No.4

Whole plants of Zostera asiatica were extracted twice with acetone/methylene chloride (A+M) and methanol (MeOH) in turn. The combined crude extracts were evaporated in vacuo and then the residue was partitioned between water and methylene chloride. The aqueous layer was fractionated into H2O and n-butanol and then the organic layer was also fractionated into 85% aq. MeOH and n-hexane, successively. The crude extracts and their solvent fractions were evaluated for their inhibitory effect on growth of human cancer cells AGS, HT-29, MCF-7, and HT-1080 cells by MTT reduction assay. Among samples tested, 85% aq. MeOH and n-hexane fractions showed strong cytotoxic effect against AGS, HT-29, and MCF-7 cells. On the other hand, for HT-1080 cell, 85% aq. MeOH fraction exhibited the strongest cytotoxic effect.

타각적 굴절검사값을 기반으로 최적의 안경처방 머신러닝 알고리즘 개발

이민지,홍주완,윤송희,임현성 대한시과학회 2023 대한시과학회지 Vol.25 No.3

목적 : 4차 산업혁명이 진행됨에 따라 타각적 굴절검사값, 수차 및 동공크기 등을 이용하여 최적의 안경처방값을 도출해주는 머신러닝(machine learning)을 개발하고자 하였다. 방법: 시력에 영향을 줄 수 있는 안질환 및 전신질환이 없고 안구 수술 이력이 없는 근시안(1,000안)을 대상으로진행하였다. I-Profilerplus(Zeiss, Berlin, Germany)를 사용하여 타각적 굴절이상도(objective-refraction) 및안구수차(ocular wavefront-aberration), 동공 크기를 측정하였고, 자각적 굴절이상도(subjective-refraction)는Visuphor500(Zeiss, Berlin, Germany)를 사용하여 구면 굴절력(S, Diopter), 원주 굴절력(C, Diopter), 난시축(Ax, °)을 측정하였다. 측정 후, 파이썬(Python, version 3.10)을 이용하여 머신러닝 모델 생성 및 예측 성능을확인하였다. 결과: 자각적 굴절이상도에서 구면 굴절력에 영향을 미치는 요인은 타각적 구면 굴절력, defocus aberration, spherical aberration, trefoil aberration 순으로 높았고, 원주 굴절력에 영향을 미치는 요인은 타각적 원주 굴절력, defocus aberration, coma aberration, trefoil aberration 순으로 높았으며, 난시 축은 타각적 난시축만영향을 미치는 것으로 나타났다. 구면 굴절력, 원주 굴절력, 난시 축의 자각적 굴절이상도와 머신러닝 예상값은차이가 없는 것으로 나타났다(p=0.976, 0.948, and 0.349, respectively). 결론 : 자각적 굴절이상도를 예측하는 머신러닝 모델을 생성하였고, 해당 모델의 예측된 값과 자각적 굴절이상도와 유의한 차이가 없는 것을 통해 예측 정확도를 확인하였으며 앞으로 개인 맞춤형 처방을 위한 정확한 안경처방값을 도출하는데 기초자료가 될 수 있을 것으로 생각된다. Purpose : As the Fourth Industrial Revolution progresses, to develop machine learning to draw subjective prescription values by using objective refraction, ocular aberrations, and pupil size. Methods : Myopic subjects (1000 eyes) with no ocular or systemic diseases that could affect vision and no history of ocular surgery were participated. I-Profilerplus (Zeiss, Berlin, Germany) was used to measure objective refraction, ocular wavefront-aberration, and pupil size. For subjective-refraction, spherical refraction (S, diopters), astigmatic refraction (C, diopters), and astigmatic axis (Ax, °) were measured using a Visuphor500 (Zeiss, Berlin, Germany). After the measurements, the machine learning model was developed using Python (version 3.10) and checked its prediction performance. Results : In the subjective refraction, the factors affecting the spherical refractive power were the highest in the order of objective spherical refractive errors, defocus aberration, spherical aberration, and trefoil aberration had the highest impact on spherical refractive power, while objective cylindrical refractive errors, defocus aberration, coma aberration, and trefoil aberration had the highest impact on cylindrical refractive power. However, the astigmatic axis was affected only by objective astigmatic axis. There was no difference between subjective refractive errors and machine learning predicted refractive errors for spherical refraction, cylindrical refraction, and astigmatic axis(p=0.976, 0.948, and 0.349, respectively). Conclusion : A machine learning model that predicts the subjective refractive errors was developed, and the prediction accuracy was confirmed through there was no significant difference between the predicted refractive errors and the subjective refractive errors. Therefore, it is thought that it can be used as basic data to derive accurate eyeglass prescription for personalized prescriptions in the future.

쇄골상부림프절을 포함한 유방암 방사선 치료 시 접합부 선량에 관한 고찰

정우현,홍주완,원희수,장남준,최병돈,Jung, Woo Hyun,Hong, Joo Wan,Won, Hui Su,Chang, Nam Jun,Choi, Byeong Don 대한방사선치료학회 2017 대한방사선치료학회지 Vol.29 No.2

목 적: 쇄골상부림프절(Supraclavicular Lymph Nodes, SCL)을 포함한 유방암 방사선 치료 시 조사야에 인접한 다엽 콜리메이터(Multileaf Collimator, MLC)가 접합부 선량에 미치는 영향을 평가하고자 한다. 대상 및 방법: 접선 조사 기법을 이용하여 SCL을 포함한 유방암 방사선 치료 환자 30명을 대상으로 120-leaf Millennium MLC가 장착된 21EX-S의 6 MV 광자선 에너지를 사용하였다. 치료계획은 유방조직과 SCL 조사야 접합부에 MLC가 모두 위치한 Plan1, 유방조직과 SCL 조사야에 MLC가 각각 위치한 Plan2, Plan3, 그리고 MLC를 모두 Retract 한 Plan4로 하였으며, SCL 조사야는 모든 계획에서 콜리메이터 각도를 $0^{\circ}$, $270^{\circ}$로 나누어 수립하였다. 치료계획에 대한 평가는 접합부 3 cm 깊이 선량(D3 cm)의 평균값으로 비교하였고, Map-CHECK을 이용하여 각 치료계획별 접합부 선량을 측정하였다. 결 과: 치료계획 비교 결과, D3cm의 평균값은 SCL 콜리메이터 $0^{\circ}$에서 4131.1, 4215.9, 4351.4, 4423.0 cGy였고, $270^{\circ}$에서 4044.3, 4246.7, 4291.1, 4441.2 cGy로 나타났다. 콜리메이터 각도에 따른 평균 선량 변화는 SCL 조사야에 MCL가 위치한 Plan1, Plan3 이 MLC가 Retract된 나머지에 비해 크게 나타났다. 그리고 접합부 선량 측정값 또한 치료계획과 같은 경향을 보였다. 결 론: 본 연구를 통해 SCL을 포함한 유방암 방사선 치료계획 시, MLC를 접합부로부터 5 mm Retract 시켜줌으로써 MLC가 접합부 선량에 미치는 영향을 줄일 수 있을 것으로 사료된다. Purpose: A purpose of this study was to compare dose of junction between breast and SCL fields in radiation therapy by MLC located at the junction. Materials and Methods: With 6 MV of 21EX-S equipped with 120-leaf Millennium MLC, treatment plans were designed with 30 patients who underwent radiation therapy using TFT. Plan 1 where the MLC was all used at the junction. In plan 2 and plan 3, MCLs were retracted 5 mm from breast and SCL, respectively. Plan 4 with all of MLC retracted at the junction were designed. In all of the plans, collimator angle for SCL field was divided into $0^{\circ}$ and $270^{\circ}$. To verify junction dose, the dose at 3cm depth of junction was compared with average value by MapCHECK. Results: In case of the SCL field with $0^{\circ}$ collimator angle, average value of D3cm was 4131.1, 4215.9, 4351.4, and 4423.0 cGy. In case of the SCL field with $270^{\circ}$ collimator angle, average value of D3cm was 4044.3, 4246.7, 4291.1, and 4441.2 cGy. In plan1 and 3, change in average dose depending on collimator angle was changed more significantly than paln2 and 4. Dose measured at 3cm depth of junction was similar to treatment plan. Conclusion: In radiation therapy plan for breast cancer with SCL, retracting MLCs from junction between breast and SCL fields will lead to decrease effect of dose of the junction.

진단용(의료용) X-선 장치 제작

도정호,홍주완,장호석,김연진,성은경 대한방사선사협회 2003 대한방사선사협회지 Vol.29 No.1

컴퓨터단층 혈관조영술에서 스텐트 사이즈의 정확한 측정을 위한 상대적 측정법의 기초연구

이승영,홍주완,강수미,김수빈,전상훈,허영철 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.5

The purpose of this study was to propose a new measurement method for accurate measurement of vessel diameter in computed tomography angiography(CTA). CTA test was performed after non-ionic iodine contrast agent was flowed at a constant rate to self-maded perfusion phantom. After obtaining raw data, images were reconstructed with multi-planar reconstruction(MPR) and maximal intensity projection(MIP). Diameters of vascular models were measured for each technique. Relative and conventional measurements were then compared. The mean diameter of the vascular model was closer to the actual measurement when relative measurement was used compared to that when conventional measurement was used both in MPR and MIP. Relative measurements of MPR and MIP were closer to actual measurement than those of conventional measurement (34% VS, 24%, p<0.05). The relative measurement method proposed in this study was closer to the actual measurement than the conventional measurement method. However, both test methods were still larger than actual results. Therefore, further study of relative measurement method is needed using this study as basic data. 본 연구의 목적은 컴퓨터단층 혈관조영술에서 혈관 직경을 정확하게 측정할 수 있는 새로운 측정 방법인 상대적 측정법의 기초연구 자료를 제공하고자 한다. 비이온성 요오드 조영제를 자체 제작한 관류 팬텀에 일정한 속도로 흐르게 한 후 컴퓨터단층 혈관조영술 검사를 시행하였다. 원시 데이터를 얻은 후 다중평면재구성 및 최대강도투사법으로 영상을 재구성하였고 장비 사에서 제공하는 거리측정 장치를 사용하여 팬텀의 직경을 측정하였다. 측정법은 고식적 측정법과 본 연구에서 제안하는 상대적 측정법을 사용하였다. 관류팬텀의 평균 직경은 다중평면재구성기법과 최대강도투사법 모두에서 상대적 측정법이 기존 측정법 보다 실측에 더 가깝게 나타났다(34% VS 24%, p<0.05). 하지만 두 가지 측정법 모두 실측보다 여전히 확대된 결과를 나타내고 있음을 확인하였다. 따라서 상대적 측정 방법에 대한 추가 연구가 필요한 실정이며, 이에 본 연구가 기초 자료를 제공할 수 있을 것이라 사료된다.

애기거머리말 추출물의 암세포 성장 억제효과

정명은,홍주완,이정임,공창숙,장재수,서영완 한국해양과학기술원 2012 Ocean and Polar Research Vol.34 No.4

In this study, crude extracts of the marine eelgrass Zostera japonica and their solvent-partitioned fractions were evaluated for their inhibitory effect against AGS, HT-1080 and MCF-7 human cancer cells using MTT assay. Each of the crude extracts (acetone/methylene, chloride, and methanol) of Z. japonica showed a significant inhibitory effect on the growth of human cancer cells. The combined crude extracts were partitioned between CH2Cl2 and water. The organic layer was further partitioned between 85% aq. MeOH and n-hexane, and the aqueous layer was then fractionated into n-BuOH and H2O, successively. Growth inhibition effects of solvent-partitioned fractions from Z. japonica on human cancer cells increased in a dose-dependent manner. Among these tested samples, the 85% aq. MeOH fraction revealed good inhibitory effects on the growth of AGS and HT-1080 human cancer cells, while the n-hexane fraction exhibited good inhibitory effects on the growth of AGS and MCF-7 human cancer cells. In addition, 85% aq. MeOH and n-hexane fractions enhanced mRNA expression of p53 gene. These results suggest that there is further scope for the isolation of active compounds from Z. japonica, which should show much stronger anticancer activity.