• Title/Summary/Keyword: Homogeneity Index

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Dosimetric Advantages of the Field-in-field Plan Compared with the Tangential Wedged Beams Plan for Whole-breast Irradiation (유방암 환자의 방사선치료에 있어서 순치료계획 세기변조방사선치료법과 쐐기접선조사기법의 선량측정 비교)

  • Kim, Suzy;Choi, Yunseok
    • Progress in Medical Physics
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    • v.25 no.4
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    • pp.199-204
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    • 2014
  • The purpose of this study is to evaluate the dosimetric outcome of the field-in-field (FIF) plans compared with tangential wedged beams (TWB) plans for whole breast irradiation of breast cancer patients. Twenty patients with right-sided breast cancer and 10 patients with left-sided breast cancer were retrospectively enrolled in this study. We generated a FIF plan and a TWB plan for each patient to compare dosimetric outcomes. The dose the homogeneity index (HI), the conformity index (CI) and the uniformity index (UI) were defined and used for comparison of the dosimetric outcome of the planning target volume (PTV). To compare the dosimetric outcome of the organs at risk, the mean dose ($D_{mean}$) and the percentage of volumes receiving more than 10, 20 and 30 Gy of the ipsilateral lung and heart were used. The FIF plans had significantly lower HI (p=0.002), higher UI (p=0.000) and CI (p=0.000) than those of the TWB plans, which means that the FIF plans were better than the TWB plans in the dosimetric comparisons of the PTV. The $V10_{lung}$ ($17.1{\pm}7.1$ vs. $18.6{\pm}6.6%$, p=0.020) and $V30_{lung}$ ($10.3{\pm}5.1%$ vs. $10.7{\pm}5.2%$, p=0.000) were lower with the FIF plans compared with those of the TWB plans, with statistical significance. For the left-sided breast cancer patients, $D_{mean}$ of the heart ($2.6{\pm}1.3$ vs. $3.2{\pm}1.4$ Gy, p=0.000), $V20_{heart}$ ($3.4{\pm}2.6$ vs. $3.6{\pm}2.8%$, p=0.005) and $V30_{heart}$ ($2.6{\pm}2.3%$ vs. $2.9{\pm}2.4%$, p=0.004) were significantly lower for the FIF plans in comparison with those of the TWB plans. The FIF plans increased the dose homogeneity, conformity and uniformity of the target volume for the whole-breast irradiation compared with the TWB plans. Moreover, FIF plans reduced the doses to the ipsilateral lung and heart.

The Effects of Gratitude Enhancement Program on Psycho-social and Physical Health of Chronic Schizophrenia (감사증진프로그램이 만성 조현병 환자의 심리사회적·신체적 건강에 미치는 효과)

  • Choo, Hyun-Sim;Kim, Joo Hyun
    • Journal of Korean Biological Nursing Science
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    • v.19 no.3
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    • pp.158-169
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    • 2017
  • Purpose: The purpose of this study was to identify the effects of the Gratitude Enhancement Program on self-esteem, interpersonal relationships, gratitude disposition, subjective happiness, stress index in patients with chronic schizophrenia. Methods: The research was designed for a nonequivalent control group before and after the test design. The subjects of this study were 29 patients in the experimental group and 28 patients in the control group. The Gratitude Enhancement Program was conducted three times a week for a total of nine sessions. Data were collected with questionnaires and measured with autonomic nervous system response (stress index) and was analyzed by t-test, chi-square test, Fisher's exact, and repeated measures ANOVA with the SPSS/WIN 23.0 program. Results: There are no significant differences in the homogeneity test of a dependent variable between groups. The experimental group showed significant higher scores of self-esteem, interpersonal relationships, gratitude disposition, and subjective happiness than the control group. There was no significant difference in the stress index between two groups. Conclusion: Based on the results of this study, this Gratitude Enhancement Program can be a good nursing intervention to improve self-esteem, interpersonal relationship, gratitude disposition, and subjective happiness for chronic schizophrenia patients.

Selection of radiation treatment plan technique at breast cancer operating technique (유방암 수술기법에 따른 방사선치료계획 기법의 선택)

  • Kim, Jeong-Ho;Bae, Seok-Hwan;Kim, Ki-Jin;Yoo, Se-Jong
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.125-130
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    • 2015
  • Techniques, using physical wedge filter and using dynamic wedge filter and FIF(Field in Field) and ISCT(Irregular Surface Compensating Technique), have been developed according to progress of radiation therapy of breast cancer. Measurement of dose was done to judge the usefulness of technique using three cases, non tissue loss after breast conserving operating and tissue loss after breast conserving operating and mastectomy. Dose indexes of breast tissue, CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage), dose index of skin, or dose indexes of lung, volume of 50 percent dose and 20 percent dose were estimated and compared. Using dynamic wedge filter is useful plan at non tissue loss allowing for high dose of lung. FIF and ISCT are useful plan at tissue loss. ISCT is useful plan at mastectomy. Henceforth, we need to apply to valid plan and body type and thorax size.

Comparison of plan dosimetry on multi-targeted lung radiotherapy: A phantom-based computational study using IMRT and VMAT

  • Khan, Muhammad Isa;Rehman, Jalil ur;Afzal, Muhammad;Chow, James C.L.
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3816-3823
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    • 2022
  • This work analyzed the dosimetric difference between the intensity modulated radiotherapy (IMRT), partial/single/double-arc volumetric modulated arc therapy (PA/SA/DA-VMAT) techniques in treatment planning for treating more than one target of lung cancer at different isocenters. IMRT and VMAT plans at different isocenters were created systematically using a Harold heterogeneous lung phantom. The conformity index (CI), homogeneity index (HI), gradient index (GI), dose-volume histogram and mean and maximum dose of the PTV were calculated and analyzed. Furthermore, the dose-volume histogram and mean and maximum doses of the OARs such as right lung, contralateral lung and non GTV were determined from the plans. The IMRT plans showed the superior target dose coverage, higher mean and maximum values than other VMAT techniques. PA-VMAT technique shows more lung sparing and DA-VMAT increases the V5/10/20 values of contralateral lung than other VMAT and IMRT techniques. The IMRT technique achieves highly conformal dose distribution to the target than other VMAT techniques. Comparing to the IMRT plans, the higher V5/10/20 and mean lung dose were observed in the contralateral lung in the DA-VMAT.

A Comparison of Field-in-Field Intensity Modulated Radiation Therapy Planning and Conventional Radiation Therapy Planning with Tangential Beam for Breast Cancer (유방암의 접선조사 시 Field-in-Field Intensity Modulated Radiation Therapy와 Conventional Radiation Therapy의 전산화 치료계획에 관한 고찰)

  • Yoo, Soon-Mi;Yeom, Mi-Suk;Kim, Dae-Sup;Back, Geum-Mun;Kwon, Kyeong-Tae
    • The Journal of Korean Society for Radiation Therapy
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    • v.22 no.1
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    • pp.41-46
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    • 2010
  • Purpose: To analyze differences in the dose uniformity for the computed breast radiation therapy planning with tangential beam between conventional RT using wedge filter and FiF-IMRT using multileaf collimator based onsizes and volumes of breasts. Materials and Methods: Thirty breast cancer patients were classified according to the sizes and volumes of the breasts using Eclipse treatment planning system ($Varian^{TM}$, USA, V8.0). Conformity Index and Homogeneity Index were computed along with Dose Volume Histogram. Results: No differencein CI (${\pm}1.2%$) was observed. However, lower mean HI (1.67%) in FiF-IMRT was observed compared to that of the conventional RT. Statically significant (P<0.01) correlation was identified between the values of ${\Delta}HI$ (%) and physical parameters such as breast volumes and separations. Conclusion: Increase in breast volume and separation improves the dose uniformities in computed radiation therapy planning for FiF-IMRT. Physical dimension of the breast should be considered to optimize the compured radiation therapy planning.

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The Study on Application of Regional Frequency Analysis using Kernel Density Function (핵밀도 함수를 이용한 지역빈도해석의 적용에 관한 연구)

  • Oh, Tae-Suk;Kim, Jong-Suk;Moon, Young-Il;Yoo, Seung-Yeon
    • Journal of Korea Water Resources Association
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    • v.39 no.10 s.171
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    • pp.891-904
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    • 2006
  • The estimation of the probability precipitation is essential for the design of hydrologic projects. The techniques to calculate the probability precipitation can be determined by the point frequency analysis and the regional frequency analysis. The regional frequency analysis includes index-flood technique and L-moment technique. In the regional frequency analysis, even if the rainfall data passed homogeneity, suitable distributions can be different at each point. However, the regional frequency analysis can supplement the lacking precipitation data. Therefore, the regional frequency analysis has weaknesses compared to parametric point frequency analysis because of suppositions about probability distributions. Therefore, this paper applies kernel density function to precipitation data so that homogeneity is defined. In this paper, The data from 16 rainfall observatories were collected and managed by the Korea Meteorological Administration to achieve the point frequency analysis and the regional frequency analysis. The point frequency analysis applies parametric technique and nonparametric technique, and the regional frequency analysis applies index-flood techniques and L-moment techniques. Also, the probability precipitation was calculated by the regional frequency analysis using variable kernel density function.

Influence of Couch and Collimator on Dose Distribution of RapidArc Treatment Planning for Prostate Cancer in Radiation Therapy (치료테이블과 콜리메이터가 전립선암 래피드아크 치료계획의 선량분포에 미치는 영향)

  • Kim, Hyung-Dong;Kim, Byung-Young;Kim, Sung-Jin;Yun, Sang-Mo;Kim, Sung-Kyu
    • Progress in Medical Physics
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    • v.23 no.2
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    • pp.99-105
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    • 2012
  • We investigated the influence of photon energy, couch and collimator angle differences between arcs on dose distribution of RapidArc treatment planning for prostate cancer. RapidArc plans were created for 6 MV and 10 MV photons using 2 arcs coplanar and noncoplanar fields. The collimator angle differences between two arcs were $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$ and $90^{\circ}$. The plans were optimized using same dose constrains for target and OAR (organ at risk). To evaluate the dose distribution, plans were analyzed using CI (conformity index), HI (homogeneity index), QOC (quality of coverage), etc. Photon energy, couch and collimator angle differences between arcs had a little influence on the target and OAR. The difference of dosimetric indices was less than 3.6% in the target and OAR. However, there was significant increase in the region exposed to low dose. The increase of V15% in the femur was 6.4% (left) and 5.5% (right) for the 6 MV treatment plan and 23.4% (left), 24.1% (right) for the noncoplanar plan. The increase of V10% in the Far Region distant from target was 54.2 cc for the 6 MV photon energy, 343.4 cc for the noncoplanar and 457.8 cc for the no collimator rotation between arcs.

Carotid sparing intensity modulated radiotherapy on early glottic cancer: preliminary study

  • Choi, Hoon Sik;Jeong, Bae Kwon;Jeong, Hojin;Song, Jin Ho;Kim, Jin Pyeong;Park, Jung Je;Woo, Seung Hoon;Kang, Ki Mun
    • Radiation Oncology Journal
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    • v.34 no.1
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    • pp.26-33
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    • 2016
  • Purpose: To compare the dose distribution between carotid sparing intensity modulated radiotherapy (IMRT) and opposed lateral field technique (LAFT), and to determine the effects of carotid sparing IMRT in early glottic cancer patients who have risk factors for atherosclerosis. Materials and Methods: Ten early glottic cancer patients were treated with carotid sparing IMRT. For each patient, the conventional LAFT plan was developed for comparison. IMRT and LAFT plans were compared in terms of planning target volume (PTV) coverage, conformity index, homogeneity index, and the doses to planning organ at risk volume (PRV) for carotid arteries, spinal cord and pharyngeal constrictor muscle. Results: Recurrence was not observed in any patients during the follow-up period. $V_{95%}$ for PTV showed no significant difference between IMRT and LAFT plans, while $V_{100%}$ was significantly higher in the IMRT plan (95.5% vs. 94.6%, p = 0.005). The homogeneity index (11.6%) and conformity index (1.4) in the IMRT plan were significantly better than those in the LAFT plans (8.5% and 5.1, respectively) (p = 0.005). The median $V_{5Gy}$ (90.0%), $V_{25Gy}$ (13.5%), and $V_{50Gy}$ (0%) for carotid artery PRV in the IMRT plan were significantly lower than those in the LAFT plan (99.1%, 89.0%, and 77.3%, respectively) (p = 0.005). Conclusion: Our study suggests that carotid sparing IMRT can significantly decrease the dose to carotid arteries compared to LAFT, and it would be considered for early glottic cancer patient with high risk of atherosclerosis.

The Effect of Inter Dental Brush Education on the Dental Plaque Index and the Degree of Halitosis for Elementary School Students (치간 칫솔 교육이 초등학생의 치면 세균막 지수와 구취 정도에 미치는 효과)

  • Lee, Ha Na;Kim, Joo Hyun
    • Journal of Korean Biological Nursing Science
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    • v.16 no.1
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    • pp.8-16
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    • 2014
  • Purpose: This study determined the effect of inter dental brush education on the dental plaque index, and the degree of halitosis for elementary school students. Methods: The study was performed on a non-equivalent control group, with a pre-test and post-test design. The study was intended for a total of 50 students. They were divided into two groups; an experimental group of 25 students and a control group of 25 students. The experimental group participated in inter dental brush education. The education took about 20 minutes, and was provided once a week, for a total of three weeks. To quantify the effect, the two groups were compared in terms of the dental plaque index and the degree of halitosis. Results: Without inter dental brush education, or a test for homogeneity, in the sense of exact equivalence of the dental plaque index and the degree of halitosis between the experimental and the control group, was supported. (p>.799, p>.876). 1) The first hypothesis, "The experimental group, who participated in inter dental brush education, would reveal a lower dental plaque indices than the control group", was supported (t=5.78, p<.001). 2) The second hypothesis, "The experimental group, who participated in inter dental brush education, would reveal a lower degrees of halitosis than the control group", was supported (t=4.49, p<.001). Conclusion: The proposed inter dental brush education is effective in improving the dental plaque index and the degree of halitosis for elementary school students.

The Representative Body Type of Lower Body of Chinese Males in Their 20s (중국(中國) 20대(代) 남성(男性)의 하반신(下半身) 대표체형(代表體型) 연구(硏究))

  • Lee, So-Young;Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.11 no.2
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    • pp.58-75
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    • 2007
  • This study held human measurement for 200 male subjects in their twenties in full age living in Ningbo City, Zhejiang Province in China. Their lower body types were classified and grouped according to shapes and sizes. Consequently, representative body type reflecting shapes, sizes, and characteristics were chosen and presented with their measurement values to be used as the basic data for slacks pattern making and fitness evaluation. The following are the results of the analysis: 1. Homogeneity analysis was given to determine the correspondence relationships among index types, indirect types, and size types. Index Type 1 (H-Round), Indirect Type 2 (Adjacent Straight Legs & Slight Slant of Lateral Lower Body), and Size Type 1 (Medium-Thick) were correlated; Index Type 2 (A-Trapezoid), Indirect Type 1 (Bow Legs & Slight Slant of Lateral Lower Body), and Size Type 3 (Small-Slim) were corresponded; Index Type 3 (A-Balance), Indirect Type 3 (Balance Legs & Large Slant of Lateral Lower Body), and Size Type 2 (Tall-Normal) were mutually related. 2. Mahalanobis distance based on each shape factor (index or indirect) and size factor (absolute) was obtained, while an index-absolute representative body type group (47 people, 24.4%) and an indirect-absolute representative body type group (45 people, 23.7%) were chosen, each reflecting shapes, sizes, and characteristics. 3. The representative body type group of lower body shapes of Chinese males in their 20s had average measurement values, such as 169.15cm (stature), 73.32cm (waist circumference), 75.76cm (omphalion waist circumference), 91.08cm (hip circumference), 106.02cm (outside leg length), 53.96cm (thigh circumference), and 74.42cm (crotch length).