• 제목/요약/키워드: Homogeneity Index

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Dosimetric Evaluation of Low-Dose Spillage Volumes for Head and Neck Cancer Using Intensity-Modulated Radiation Therapy and Volumetric Modulated Arc Therapy Treatment Techniques

  • Kumar, Gourav;Bhushan, Manindra;Kumar, Lalit;Kishore, Vimal;Raman, Kothanda;Kumar, Pawan;Barik, Soumitra;Purohit, Sandeep
    • 한국의학물리학회지:의학물리
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    • 제32권3호
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    • pp.70-81
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    • 2021
  • Purpose: This study was designed to investigate the dosimetric difference between intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in head and neck cancer (HNC). The study primarily focuses on low-dose spillage evaluation between these two techniques. Methods: This retrospective study involved 45 patients with HNC. The treatment plans were generated using the IMRT and VMAT techniques for all patients. Dosimetric comparisons were performed in terms of target coverage, organ-at-risk (OAR) sparing, and various parameters, including conformity index, uniformity index, homogeneity index, conformation number, low-dose volumes, and normal tissue integral dose (NTID). Results: No significant (P>0.05) difference in planning target volume coverage (D95%) was observed between IMRT and VMAT plans for supraglottic larynx, hard palate, and tongue cancers. A decrease in dose volumes ranging from 1 Gy to 30 Gy was observed for VMAT plans compared with those for IMRT plans, except for V1Gy and V30Gy for supraglottic larynx cancer and V1Gy for tongue cancer. Moreover, decreases (P<0.05) in NTID were observed for VMAT plans compared with that for IMRT plans in supraglottic larynx (4.50%), hard palate (12.80%), and tongue (7.76%) cancers. In contrast, a slight increase in monitor units for VMAT compared with those for IMRT in supraglottic larynx (0.46%), hard palate (2.54%), and tongue (7.56%) cancers. Conclusions: For advanced-stage HNC, both IMRT and VMAT offer satisfactory clinical plans. VMAT offers a conformal and homogeneous dose distribution with comparable OAR sparing and higher dose falloff outside the target volume than IMRT, which provides an edge to reduce the risk of secondary malignancies for HNC over IMRT.

손상위험장기에 인접한 표적 Coverage 개선을 위한 Planning Target Volume 중복 설정에 관한 연구 (Study of overlapping setting up of Planning Target Volume for Improving Target Coverage adjacent Organ At Risk)

  • 이정웅;김보겸;문준기;우헌;이양훈;전창우;이제희
    • 대한방사선치료학회지
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    • 제31권2호
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    • pp.33-41
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    • 2019
  • 목 적: 용적변조회전 방사선치료(Volumetric Modulated Arc Therapy, VMAT)시, Planning Target Volume(PTV)을 중복 설정하여 손상위험장기(Organ At Risk, OAR)에 인접한 PTV Coverage 감소를 개선하기 위한 연구이다. 대상 및 방법: 본원에서 전뇌(Whole Brain), 담낭(Gall Bladder), 직장(Rectum) 방사선치료를 받은 환자를 대상으로 하였으며, PTV 내 Coverage가 부족한 부분에 PTV를 중복 적용한 치료계획과 적용하지 않은 치료계획으로 구성하여 Coverage 변화와 최대선량, 선량균질지수(Homogeneity Index, H.I.), 처방선량지수(Conformity Index, C.I.)를 비교하였으며, 손상위험장기(Organ At Risk, OAR)의 최대선량과 평균선량의 변화 또한 비교하였다. 결 과: 중복하여 적용한 PTV의 Coverage는 모든 환자에게서 증가하였고, 이에 따른 영향으로 전체 Coverage 또한 4명의 환자에게서 증가하였다. PTV의 최대선량은 5명의 환자에게서 증가하였으며, 모든 환자의 선량균질지수와 처방선량지수는 큰 차이를 나타내지 않았다. 수정체의 최대선량은 최대 1.12배 증가하였으나, 뇌줄기의 경우 2명의 환자에게서 최대선량이 감소하였다. 안구의 평균선량은 최대 1.15배 증가하였으며, 양측 이하선의 경우 큰 차이를 나타내지 않았다. 담낭암 환자의 경우 간과 결장의 평균선량은 각각 0.95배, 0.94배 감소하였으며, 십이지장의 평균선량은 큰 차이가 없었다. 직장암 환자의 경우 OAR로 설정한 양측 대퇴골두와 방광 모두 평균선량은 감소하였으며, 전체 MU는 1명을 제외한 4명의 환자에게서 비슷한 수준으로 나타났다. 결 론: OAR의 선량제한을 고려해가면서 적절하게 사용한다면, PTV의 Coverage 개선에 유용한 방법이라 생각한다.

건강아파트 주민지도자 대상 지역사회역량강화 교육의 효과 (Effects of a Community-based Empowerment Program for Resident Leaders Participating in the Healthy Apartment Project)

  • 최인희;이정미;조인숙;강서영;김윤경
    • 근관절건강학회지
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    • 제25권1호
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    • pp.21-29
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    • 2018
  • Purpose: The purpose of this study was to investigate the effects of a community-based empowerment program for resident leaders participating in the Healthy Apartment project. Methods: The design of this study was a single group pre-post test design. This program was consisted of 4-hour sessions. The total participants were 22 leaders. Results: The participants showed significant changes in social support (Z=-2.33, p=.020), collective action (Z=-3.91, p<.001), conflict and homogeneity (Z=-2.03, p=.042), and community perception index (Z=-3.97, p<.001) as sub factors of the individual level of SC-IQ (Integrated Questionnaire for the Measurement of Social Capital). They also showed significant changes in necessity of the resident organization (Z=-4.13, p<.001), resident participation (Z=-3.84, p<.001), convergence of resident opinion (Z=-3.94, p<.001) and the role of community leaders (Z=-3.94, p<.001) as sub factors of the perception and confidence of resident leaders (Z=-3.85, p<.001). Conclusion: Results indicate that the community-based empowerment program is effective in perceptions of social capital on the individual level and improvement of recognition as resident leaders and confidence for resident leaders.

건강증진행위 설명요인에 대한 메타분석 (A Meta-Analysis of Explanatory Variables of Health Promotion Behavior)

  • 박영주;이숙자;박은숙;유호신;이재원;장성옥
    • 대한간호학회지
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    • 제30권4호
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    • pp.836-846
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    • 2000
  • This Meta-Analysis of 18 studies was conducted to determine the magnitude of th relationship between health promotion behavior and each of explanatory variables. The studies were measured using Health Promoting Life Style(HPLP) developed by Walker and others based on Pender's definiton of health promoting behavior. The sample was collected by searching for The Journal of Korean Academy Nursing Society, The Journal of Korean Women's Health Nursing Academic Society,The Journal of Korean Academic Society of Adult Nursing, Journal of Korean Community Nursing, The Journal of Fundamentals of Nursing, The Journal of Korean Nursing Administration Academic Society, The Korean Journal of Child Health Nursing, The Journal of Korean Psychiatric Academic Society, the dissertations for mater degree or doctoral dissertations for the period from 1980 to 1998. The explanatory variables measured more than 2 times in studies were self-efficacy, perceived health status, self-esteem, internal, powerful-others and chance dimensions of health locus of control, perceived benefits, hardiness, wellbeing and clinical demensions of health concepts, and quality of life(life satisfaction). Effect sizes were calculated by unweighted mean r, weighted mean r by sample size and weighted mean r by quality index score after homogeneity test. The mean r effect size indicator range of each predictor variable were as follows; quality of life (0.50- 0.52), self-efficacy (0.46-0.47), hardiness (0.42-0.44), self-esteem(0.41-0.43), health locus of control- internal(0.32-0.34), health locus of control- powerful others (0.25-0.31), perceived health status(0.18-0.19) and clinical dimensions of health concepts (0.16-0.17).

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전립선암 영상유도방사선치료 시 pCT와 CBCT에 따른 치료계획별 체적선량의 변화 (Changes in Volume Dose by Treatment Plan According to pCT and CBCT in Image-guided Radiation Therapy for Prostate Cancer)

  • 원영진;김정훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제41권3호
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    • pp.209-214
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    • 2018
  • The results of CBCT was obtained using image guided radiation therapy for radiation therapy in 5 prostate cancer patients. Using these results, we compared and evaluated the dose changes according to the treatment plan depending on the volume and position of bladder, rectum, and prostate. The 28 images of CBCT were acquired using On-Board Imaging device before radiotherapy. After the outline of bladder, rectum, and PTV, pCT images and CBCT images for radiotherapy were treated respectively. The volume of the bladder was increased by 105.6% and decreased by 45.2%. The volume of the rectum was increased by 30.5% and decreased by 20.3%. Prostate volume was increased by 6.3% and decreased by 12.3%. The mean dose of the rectum was higher in the CBCT than in the pCT, and V40 (equivalent to 40 Gy) of the bladder showed a reduction in all treatment regimens in the CBCT than in the pCT. Conformity treatment and homogeneity index of PTV showed better results in all treatment regimens using pCT than CBCT. It was found that the dose distribution of the pelvic internal organs varied greatly according to the patient 's condition and pretreatment.

소득 분포의 양극화 추이 (Bi-Polarization of the Income Distribution In Korea: 1997-2003)

  • 신동균;전병유
    • 노동경제논집
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    • 제28권3호
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    • pp.77-109
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    • 2005
  • 한 사회가 가지고 있는 내재적 갈등의 정도는 전통적인 소득불평등이라기보다는 양극화지수로 보다 잘 표현될 수 있다. 현 연구에서는 Esteban-Ray류의 '집단내 동질성-집단간 이질성' 접근법에 근거하여 양극화 개념을 소개하고 그들이 개발한 지수를 이용하여 외환 위기 직전인 1997년도 이래 소득분포의 양극화가 어떻게 진행되어 왔는가를 분석하였다. 주요 발견 내용을 다음과 같다. 첫째, 총가구소득을 이용하여 분석할 경우, 지니 계수로 표현되는 전통적인 소득불평등 지수와 비교하여 양극화 지수는 훨씬 빠른 속도로 증가해왔다. 이는 소득을 기준으로 볼 때 한국 사회에 잠재해 있는 사회 갈등 수준이 지니 계수로 표현되는 것보다 훨씬 심각한 속도로 증가해 왔음을 의미한다. 둘째, 최근의 외환위기 이전과 비교하여 이후에 양극화 지수의 값이 전반적으로 증가해온 것은 일차적으로 저소득층과 고소득층 사이의 소득격차가 증가해왔기 때문이지만 집단 내 (특히 저소득 집단 내) 소득격차가 줄어들었기 때문이기도 하다. 셋째, 총가구소득의 양극화는 근로소득이라기보다는 주로 비근로소득의 양극화에 의해 주도되어왔다.

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불법목재의 교역 제한 조치가 국내 목재 시장에 미치는 영향 분석 (Analysis of the Influences on Domestic Wood Market by Prohibiting Illegal Wood Products Trade)

  • 김동현;박현;이호상
    • 한국산림과학회지
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    • 제107권3호
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    • pp.305-315
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    • 2018
  • 이 연구의 목적은 "목재의 지속가능한 이용에 관한 법률"에 근거하여 불법목재의 교역을 제한하는 제도 시행에 앞서 국내 목재시장에 미치는 영향을 분석하기 위하여 수행하였다. 시나리오 작성을 위해 부패인식지수를 활용하였고 이를 바탕으로 균형대체방정식 모형을 이용하여 정책실험을 수행하였다. 원목의 균형가격 변화율은 0.066%~0.071% 범위에서 상승할 것으로 분석되었다. 원목가격의 상승은 파생수요의 관계에 있는 제재목의 생산비에 반영되어 제재목의 공급량을 감소시킨다. 상품유형별로 대체효과에 의한 국산재 수요 확대와 국내 가격상승에 의한 공급량 확대를 감안하여 분석한 결과, 국산 제재목 가격 변화율의 범위는 0.885%~4.179%에서 증가하는 것으로 분석되었으며 이에 따라 국산 제재목의 공급량은 적어도 5.367% 증가될 것으로 나타났다.

요양병원 환자분류체계 개발 (Development of Patient Classification System in Long-term Care Hospitals)

  • 이지윤;윤주영;김정회;송성희;주지수;김은경
    • 간호행정학회지
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    • 제14권3호
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    • pp.229-240
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    • 2008
  • Purpose: To develop the patient classification system based on the resource utilization for reimbursement of long-term care hospitals in Korea. Method: Health Insurance Review & Assessment Service (HIRA) conducted a survey in July 2006 that included 2,899 patients from 35 long-term care hospitals. To calculate resource utilization, we measured care time of direct care staff (physicians, nursing personnel, physical and occupational therapists, social workers). The survey of patient characteristics included ADL, cognitive and behavioral status, diseases and treatments. Major category criteria was developed by modified delphi method from 9 experts. Each category was divided into 2-3 groups by ADL using tree regression. Relative resource use was expressed as a case mix index (CMI) calculated as a proportion of mean resource use. Result: This patient classification system composed of 6 major categories (ultra high medical care, high medical care, medium medical care, behavioral problem, impaired cognition and reduced physical function) and 11 subgroups by ADL score. The differences of CMI between groups were statistically significant (p<.0001). Homogeneity of groups was examined by total coefficient of variation (CV) of CMI. The range of CV was 29.68-40.77%. Conclusions: This patient classification system is feasible for reimbursement of long-term care hospitals.

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생화학적 유전표지인자에 의한 한국재래닭의 유전특성 분석 (Analysis of Genetic Characteristics by Biochemical Genetic Markers in Korean Native Chicken)

  • 이학교;정호영;한재용;정의룡
    • 한국가금학회지
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    • 제23권3호
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    • pp.135-144
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    • 1996
  • This study was carried out to clarify the genetic constitution of biochemical polymorphic loci controlling blood protein and enzymes as genetic rnarkers in Korean native chicken(KNG) population Blood samples were collected from 230 KNG representing three colored-lines(reddish-, yellowish- and blackish- brown) raised in Daejeon branch of National Livestock Research Institute. Eight blood marker loci, transferrin(Tf), post-albumin(Pas), albumin(Alb), amylase-1(Arny-1), es-terase-1(Es-1), alkaline phosphatase(Akp), catalase(Cat) and hemoglobin(Hh) were analyzed by using starch, agarose and polyacrylamide gel electrophoresis. Based on the gene frequencies of polymorphic marker loci, the genetic characteristics of KNF population was analyzed, and the genetic ariability within population was quantified. The genetic relationships between KNC and other native fowls or improved breeds were also estimated. The gene frequencies of Tf, Pas and AIb loci were similar to those of improved breeds among the seven biochemical polymorphic loci, while gene frequencies of Cat and Es-i loci were remarkably different between KNC and improved breeds. Gene frequencies of amy-i and Akp loci were similar to those of New Hampshire and Rhode Island Red and White Leghorn, respectively. However in comparison with other improved breeds, great differences were observed in gene frequencies of these loci The average heterozygosity, effective number of alleles and homogeneity index for the seven loci combined were estimated to be .334, 1.639 and .373, respectively. Based on the dendrogram and genetic distances, the KNC was genetically closer to New Hampshire, Plymouth Rock and Rhode Island Red breeds than to the White Leghorn breed.

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Effect of Charge Carrier Lipid on Skin Penetration, Retention, and Hair Growth of Topically Applied Finasteride-Containing Liposomes

  • Lee, Sang-Im;Nagayya-Sriraman, Santhosh-Kumar;Shanmugam, Srinivasan;Baskaran, Rengarajan;Yong, Chul-Soon;Yoon, Sang-Kwon;Choi, Han-Gon;Yoo, Bong-Kyu
    • Biomolecules & Therapeutics
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    • 제19권2호
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    • pp.231-236
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    • 2011
  • The aim of this study was to investigate the effect of charge carrier lipid on the skin penetration, retention, and hair growth of topically applied finasteride-containing liposomes. Finasteride-containing liposomes were prepared by traditional thin film hydration method using Phospholipon$^{(R)}$ 85 G and cholesterol with or without charge carrier lipid (1,2 dimyristoyl-sn-glycero-3-phosphate or 1,2-dioleoyl-trimethylammonium-propane for anionic and cationic charge, respectively). Freshly prepared finasteride-containing liposome suspension was applied on the hairless mouse skin, and skin penetration and retention were measured using Keshary-Chien diffusion cell. Non-liposomal formulation (ethanol 10% solution containing 0.5 mg/ml of FNS) was also used as a control. The amount of finasteride in the diffusion cell and mouse skin was measured by HPLC. The hair growth was evaluated using depilated male C57BL/6N mice. Mean particle size of all finasteride-containing liposomes was less than a micron, and polydispersity index revealed size homogeneity. Skin penetration and retention studies showed that significantly less amount of finasteride was penetrated when applied as anionic liposome while more amount of the drug was retained. Specifically, in liposome prepared with 10% anionic charge carrier lipid, penetration was 12.99 ${\mu}g/cm^2$ while retention was 79.23 ${\mu}g/cm^2$ after 24 h of application. In hair growth study, finasteride-containing anionic liposomes showed moderate efficacy, but the efficacy was not found when applied as cationic liposomes. In conclusion, topical application of finasteride using anionic liposome formulation appears to be useful option for the treatment of androgenetic alopecia to avoid systemic side effects of the drug.