• 한국의학물리학회지:의학물리
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• 제28권4호
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• pp.164-170
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• 2017

One of the methods to consider the effect of respiratory motion of a tumor target in radiotherapy is to establish a treatment plan with the internal target volume (ITV) created based on an accurate analysis of the target motion displacement. When this method is applied to intensity modulated radiotherapy (IMRT), it is expected to yield a different treatment dose distribution under the motion condition according to the IMRT method. In this study, we prepared ITV-based IMRT plans with conventional IMRT using fixed gantry angle beams, RapidArc using volumetric modulated arc therapy, and tomotherapy using helical therapy. Then, the variation in dose distribution caused by the target motion was analyzed by the dose measurement in the actual motion condition. A delivery quality assurance plan was prepared for the established IMRT plan and the dose distribution in the actual motion condition was measured and analyzed using a two-dimensional diode detector placed on a moving phantom capable of simulating breathing movements. The dose measurement was performed considering only a uniform target shape and motion in the superior-inferior (SI) direction. In this condition, it was confirmed that the error of the dose distribution due to the target motion is minimum in tomotherapy. This is thought to be due to the characteristic of tomotherapy that treats the target sequentially by dividing it into several slices. When the target shape is uniform and the main target motion direction is SI, it is considered that tomotherapy for the ITV-based IMRT method has a characteristic which can reduce the dose difference compared with the plan dose under the target motion condition.

• Journal of Multimedia Information System
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• 제6권4호
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• pp.293-302
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• 2019

In the past, there was a theory that influenza wasn't transmitted directly from birds but was infected to humans via swains. Recently, molecular level research has progressed, and it was confirmed that the avian influenza virus can directly infected to human lung and intestinal epithelial cells. Three pandemicsin the past 100 years were also infected to humans directly from birds. In view of such scientific background, we are developing a method for screening sick birds by monitoring the physiological characteristics of birds in a contactless manner with sensors. Here, the movement of respiratory muscles and abdominal muscles under autonomic innervation was monitored using a magnet and Hall sensor sewn on the thoracic wall, and other multimedia devices. This paper presents and discusses the results of experiments involving continuous periodic noise discovered during flight experiments with a data logger mounted on a Japanese pheasant from 2012 to 2015. A brief summary is given as the below: 1. Magnet and Hall sensor sewn to the left and right chest walls, bipolar electrocardiograms between the thoracic walls, posterior thoracic air sac pressure, angular velocity sensors sewn on the back and hips, and optical reflection of LEDs (blue and green) from the skin of the hips allow observation of periodic vibrations(fasciculations) in the waves. No such analysis has been reported before. 2. These fasciculations are presumed to be derived from muscle to maintain and control air sac pressure. 3. Since each muscle fiber is spatially Gaussian distributed from the sympathetic nerve, the envelope is assumed to plot a Gaussian curve. 4. Since avian trunk muscles contract periodically at all time, we assume that the sympathetic nerve dominates in their control. 5. The technique of sewing a magnet to the thoracic wall and measuring the strength of the magnetic field with a Hall sensor can be applied to screen for early stage of avian influenza, with a sensor attached to the chicken enclosure.

• 한국균학회지
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• 제28권1호
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• pp.26-31
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• 2000

팽이버섯의 자실체형성 과정에 특이적으로 발현하는 FVFD16과 FVFD30 유전자의 genomic 클론을 단리하여 염기서열을 분석하였다. FVFD16은 Open Reading Frame(ORF)내에 2개의 intron이 관찰되었고, FVFD30 유전자에서는 4개의 intron이 관찰되었다. 또한 intron의 특징적인 염기서열인 GT/AG의 rule과도 일치하고 있음이 밝혀졌다. FVFD16과 FVFD30의 두 유전자 모두에서 진핵생물의 promoter영역에서 자주 관찰되는 CAAT box와 유사한 배열과 TATA box가 존재했다. 또한, 전사개시점의 바로 앞에서 관찰되어지는 CT-rich의 영역이 존재하고 있었으며, 특히 FVFD30에서는 전사개시 시에 중요한 역할을 할 것으로 예상되는 CCACC의 서열이 관찰되었다. 한편 FVFD16 genomic클론의 염기서열 분석결과 cDNA클론과 80%의 상동성을 나타내는 gene family임이 밝혀졌다. 여러 가지 제한효소에 의한 genomic southern blot 분석결과 FVFD16과 FVFD30은 2번 이상의 반복배열 또는 gene family의 존재가 확인되었다.

• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.1-6
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• 2019

Purpose: This study conducts a comparative evaluation of the skin dose in CyberKnife (CK) and Helical Tomotherapy (HT) to predict the accurate dose of radiation and minimize skin burns in head-and-neck stereotactic body radiotherapy. Materials and Methods: Arbitrarily-defined planning target volume (PTV) close to the skin was drawn on the planning computed tomography acquired from a head-and-neck phantom with 19 optically stimulated luminescent dosimeters (OSLDs) attached to the surface (3 OSLDs were positioned at the skin close to PTV and 16 OSLDs were near sideburns and forehead, away from PTV). The calculation doses were obtained from the MultiPlan 5.1.2 treatment planning system using raytracing (RT), finite size pencil beam (FSPB), and Monte Carlo (MC) algorithms for CK. For HT, the skin dose was estimated via convolution superposition (CS) algorithm from the Tomotherapy planning station 5.0.2.5. The prescribed dose was 8 Gy for 95% coverage of the PTV. Results and Conclusions: The mean differences between calculation and measurement values were $-1.2{\pm}3.1%$, $2.5{\pm}7.9%$, $-2.8{\pm}3.8%$, $-6.6{\pm}8.8%$, and $-1.4{\pm}1.8%$ in CS, RT, RT with contour correction (CC), FSPB, and MC, respectively. FSPB showed a dose error comparable to RT. CS and RT with CC led to a small error as compared to FSPB and RT. Considering OSLDs close to PTV, MC minimized the uncertainty of skin dose as compared to other algorithms.

• 한국방사선학회논문지
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• 제16권6호
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• pp.709-718
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• 2022

본 연구의 목적은 토모테라피 방사선치료에서 고밀도 알루미늄, 티타늄, 강철 금속 삽입물에 대한 단층촬영(CT)을 평가하고 자 하였다. 다양한 밀도의 원통형 막대를 포함한 금속 삽입물과 함께 원통형 토모팬텀을 이용하여 영상을 얻었다. 총 세 가지의 CT 영상에 대해 평균 CT 값(number)와 표준 편차를 구하고, 치료계획 선량평가도 수행하였다. 고밀도 금속 삽입물이 CT값과 변화가 가장 컸다. 타겟에 대한 선량평가(적합성 지수, CI)에서 반복적 금속 인공물 감소 알고리즘(iMAR)이 적용된 영상이 그렇지 않은 영상에 비해 약 20% 좋았으나 유의한 차이는 없었다. iMAR은 표적 및 장기의 묘사에 도움을 주고 토모테라피를 이용한 3차원 입체조형 방사선치료기술(3D-CRT)에서 불확실성을 줄이는 데 도움이 될 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제37권1호
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• pp.37-47
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• 2014

본 연구는 토모테라피(Accuray Inc, Sunnyvale, CA, USA)의 자동영상정합 과정에서 조정인자에 따른 종축과 회전축의 오차를 분석하였다. 다섯그룹(두부, 경부, 흉부, 복부, 골반부)으로 구분된 총 50명의 치료가 종료된 환자를 대상으로 하였고, 총 500개의 megavoltage computed tomography (MVCT) 영상을 분석하였다. 모의치료에서 kilovoltage computed tomography (kVCT)영상을 얻었고, 치료계획을 위하여 토모테라피 Hi-Art II 치료계획시스템(Accuray Inc, Sunnyvale, CA, USA)을 사용하였다. 매 회 치료 전 자동영상정합 과정을 시행하였고, 종축과 회전축의 오차를 기록하였다. 종축과 회전축의 일치도(adjustments)에서 자동영상정합을 분석하기 위하여 총 아홉 가지 조정인자를 적용하였고, 각 그룹의 계통적(systematic, ${\Sigma}$)과 통계적(random, RMS) 오차에 대하여 종합적 평균오차(overall mean value, M)를 구했다. 각 그룹 간 회전축 일치도의 종합적 평균오차에서 밀도와 해상도에 따른 다양한 조정인자에 의한 차이를 보였다. 밀도와 해상도가 높아짐에 따라 회전축 일치도에서 편차가 작았다. 그러므로, 토모테라피에서 "full-image"모드와 "standard"해상도를 이용한 자동영상정합은 정확한 오차 확인이 가능하고, 환자 재위치잡이(repositionning) 및 보정(correcting)에 도움이 될 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제36권4호
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• pp.327-335
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• 2013

토모테라피를 이용한 3D-CRT의 임상적 적용 사례를 Helical mode와 Direct mode로 구분하여 치료목적에 따라 주 치료목적 및 보조적 치료 목적으로 적용된 사례에 대해 선량학적 평가를 시행하였고 기존의 라이낙을 이용한 기법과 종양의 발생 부위별 선량학적 분포의 차이를 비교, 분석하였다. 선량 분석은 육종, 뇌척수조사, 유방, 뇌, 췌장, 척추 전이, 상대정맥 증후군, 식도에 토모테라피를 이용한 3차원 입체조형 방사선치료로 치료받는 환자 8명을 대상으로 Helical mode와 Direct mode, 라이낙 기반 치료 기법 사이의 치료 계획 간 비교하였으며, 선량분석은 선량 체적 히스토그램과 등선량 곡선을 이용했다. Direct mode로 치료한 육종, 뇌척수 조사 환자의 경우 체적 길이에 대한 영향을 받지 않아 Junction effect 없는 선량적 결과를 보여주었고, 유방 환자는 D 99%와 D 95%의 선량에서 $49.2{\pm}0.4$ Gy와 $49.9{\pm}0.4$ Gy, V 105%와 V 110%에서 0%로 나타났다. Helical mode로 치료한 뇌, 췌장, 척추 전이 환자에서 dosimetric block을 이용해 정상조직의 선량을 효과적으로 줄일 수 있었고, 상대정맥 증후군 환자는 선량 제한(dose limitation)을 통해 방사선 치료를 재 실시해도 척수선량을 38 Gy이하로 효과적으로 제한할 수 있었다. 식도 환자에서는 기존에 다른 기법과 함께 추가조사 목적으로 사용하여 총 척수선량을 45 Gy 이하로 하고 폐의 V 20%을 20% 이하로 제한할 수 있었다. 토모테라피를 이용한 3차원 입체조형치료는 기존 선형가속기를 이용한 3차원 입체조형 방사선치료에 비해 선량적으로 제한되는 부분을 개선해주고 임상적으로 적절한 선량분포를 구현하는데 효과적인 방법 중의 하나라고 사료된다.

• 한국의학물리학회지:의학물리
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• 제26권1호
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• pp.6-11
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• 2015

본 연구의 목적은 토모다이렉트 3D-CRT (TD 3D-CRT)을 이용한 유방암 방사선치료에서 회전축(roll, pitch, and yaw) 오차를 분석하고 자 하였다. TD-3DCRT로 치료가 종료된 유방암 환자 총 20명을 선정하였고, 총 80회의 MVCT 영상을 바탕으로 시스템(systematic), 임의(random) 오류를 포함한 환자위치잡이 오차(patient setup errors)와 치료 여백(treatment margin, mm)을 후향적으로 분석하였다. 또한, 각 환자에 대한 회전축 오차 분석은 자동영상정합(automatic image registration)을 이용하였다. X, Y, Z 방향에 대한 치료여백은 각각 4.2 mm, 6.2 mm, 6.4 mm였다. 회전축 오차에 대한 평균 각도(degree)는 roll, pitch, yaw가 각각 0.3도, 0.5도, 0.1도였고, 시스템과 임의 오류는 모두 1도 이내였다. 전반적으로 환자 위치잡이 오차는 Y와 Z방향에서 X에 비하여 높게 나타났다. 본 연구에서 회전축 오차 각도가 2도 이내는 roll, pitch, yaw에서 각각 95.1%, 98.8%, 97.5% 분포였다. 그러나, 치료영역의 길이가 길어짐에 따라 치료 중심지점을 기준으로 상부와 하부의 가장자리(Edge)가 틀어지게(Twisted)될 가능성이 높아질 수 있다. 따라서 치료의 정확성과 재현성을 위하여 각 환자의 특성을 고려하고, 회전축 오차를 주기적으로 확인할 필요가 있다.

• Radiation Oncology Journal
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• 제37권4호
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• pp.271-278
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• 2019

Purpose: To investigate the differences in treatment outcomes between two radiation techniques, intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT). Materials and Methods: We retrospectively analyzed 160 (IMRT = 23, 3DCRT = 137) patients with stage I glottic cancer treated from January 2005 through December 2016. The IMRT was performed with TomoTherapy (16 patients), volumetric-modulated arc therapy (6 patients), and step-and-shoot technique (1 patient), respectively. The 3DCRT was performed with bilateral parallel opposing fields. The median follow-up duration was 30 months (range, 31 to 42 months) in the IMRT group and 65 months (range, 20 to 143 months) in the 3DCRT group. Results: The 5-year overall survival and 3-year local control rates of the 160 patients were 95.7% and 91.4%, respectively. There was no significant difference in 3-year local control rates between the IMRT and 3DCRT groups (94.4% vs. 91.0%; p = 0.587). Thirteen of 137 patients in the 3DCRT group had recurrences. In the IMRT group, one patient had a recurrence at the true vocal cord. Patients treated with IMRT had less grade 2 skin reaction than the 3DCRT group, but this had no statistical significance (4.3% vs. 21.2%; p = 0.080). Conclusion: IMRT had comparable outcomes with 3DCRT, and a trend of less acute skin reaction in stage I glottic cancer patients.

• Architectural research
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• 제8권1호
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• pp.1-7
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• 2006

Various housing measures are needed for the rapidly aging society of Korea. In particular, the welfare policy for the elderly has changed towards the community care. Taking this fact into consideration, it is necessary to have the establishment of a system that offers the elderly appropriate welfare services at their appropriate residence (ageing in place) for the effectiveness of the community care. In this aspect, there are a number of implications to Korea to study merits and demerits of the Health Facilities for the Aged (HFA) in Japan. The society of Japan has been rapidly aging since 1970, and Korea is to face the same situation. As for the data of this study, a total of 2,393 facilities (as of November 1999) mentioned in the annual report of the Japanese Ministry of Health, Labor and Welfare were classified based on types of their establishment: (1) free-standing structures (603 facilities); (2) annexes to hospitals (981 facilities); (3) annexes to welfare facilities (511 facilities); and (4) annexes to clinics (298 facilities). Next, 239 facilities were selected through taking a sample of 10 percent from each type of the HFA mentioned above. This was done through the random sampling method with the computer program of MS EXCEL. The Implications of the results of analyses are as follows. First, most of the health facilities were planned with the scale that was larger than the scale of standard special nursing homes in terms of the total floor area. Precise equations that were to obtain precise results of the scale of the HFA and the appropriate number of residents were obtained through the method of the regression analysis. Korea and Japan have similarities in terms of culture, society and family relations; however, the two countries also have differences in terms of the application of laws on the establishment of houses, hospitals, and welfare facilities. As for planning the scale of the HFA, the realities of Korea should be considered. Second, as for the functional aspect of the HFA with a condition of returning home, the place before and after the HFA showed the pattern of 'from a residential place to a residential place' and 'from a hospital to a hospital.' This reveals a close correlation with the types of the HFAs and operational ways of the facilities. Its cause is considered to be the aspect of the operation and management of the HFA rather than the aspect of its function of providing services in association with medical and health facilities. Therefore, when intermediate welfare facilities are considered in Korea, it is strongly advised to consider the problem of annexes to other facilities and efficiency of sharing of the facilities in terms of its operation and management.