• 제목/요약/키워드: Dose Distribution

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Influence of Delayed Gastric Emptying in Radiotherapy after a Subtotal Gastrectomy (위부분절제술 후 방사선치료에서 음식물 배출지연에 따른 영향)

  • Kim, Dong-Hyun;Kim, Won-Taek;Lee, Mi-Ran;Ki, Yong-Gan;Nam, Ji-Ho;Park, Dal;Jeon, Ho-Sang;Jeon, Kye-Rok;Kim, Dong-Won
    • Radiation Oncology Journal
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    • v.27 no.4
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    • pp.194-200
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    • 2009
  • Purpose: This aim of this study was to evaluate changes in gastric volume and organ position as a result of delayed gastric emptying after a subtotal gastrectomy performed as part of the treatment of stomach cancer. Materials and Methods: The medical records of 32 patients who underwent concurrent chemoradiotherapy after a subtotal gastrectomy from March 2005 to December 2008 were reviewed. Of these, 5 patients that had more than 50 cc of residual gastric food detected at computed tomography (CT) simulation, were retrospectively enrolled in this study. Gastric volume and organ location was measured from CT images obtained before radiotherapy, twice weekly. In addition, authors evaluated the change of radiation dose distribution to planning the target volume and normal organ in a constant radiation therapy plan regardless of gastric volume variation. Results: A variation in the gastric volume was observed during the radiotherapy period (64.2~340.8 cc; mean, 188.2 cc). According to the change in gastric volume, the location of the left kidney was shifted up to 0.7 - 2.2 cm (mean, 1.2 cm) in the z-axis. Under-dose to planning target volume (V43, 79.5${\pm}$10.4%) and over-dose to left kidney (V20, 34.1${\pm}$12.1%; Mean dose, 23.5${\pm}$8.3 Gy) was expected, given that gastric volume change due to delayed gastric emptying wasn't taken into account. Conclusion: This study has shown that a great change in gastric volume and left kidney location may occur during the radiation therapy period following a subtotal gastrectomy, as a result of delayed gastric emptying. Detection of patients who experienced delayed gastric emptying and the application of gastric volume variation to radiation therapy planning will be very important.

The Comparison of DVH between Multiple arc FSRT and Conformal FSRT (Multiple arc FSRT와 Conformal FSRT의 DVH 비교)

  • Kim Ki-Hwan;Kim Jun-Sang;Jang JiYoung;Kim Jae-Sung;Kim Seong-Ho;Song Chang-Joon;Park Min-Kyu;Cho Moon-June
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.261-267
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    • 1999
  • Purpose : In FSRT (Fractionated stereotactic radiotherapy) planning, we studied the usefulness between multiple arc FSRT and conformal FSRT by comparing tumor shape and DVH (dose volume histogram). Materials and Methods In Chungnam Univ. hospital, we had treated the sixteen patients with FSRT from Aug. 1997 to Dec. 1998. In choosing multiple arc FSRT or conformal FSRT, we had considered If (irregular factor) after calculating tumor volume and surface area. We had considered multiple arc FSRT if tumor shape was similar to sphere or the value of If was less than 1.25, conformal FSRT if tumor shape was very irregular or If was more than 1.3. For evaluation of treatment planning, we had considered the appropriate DVH for tumor volume and for critical organs. Results : The errors between reference point and the coordinates point on AP, Lat radiography were less than 1 mm before treatment. We had planned $3\~$5 arcs for multiple arc FSRT, $5\~6$ports for conformal FSRT. The mean dose distribution of tumor volume of cumulative DVH between multiple arc FSRT and conformal FSRT was 90.6, 85%, respectively. The dose of critical organs irradiated was less than $5\%$ maximum dose of cumulative DVH. Conclusion : We had obtained the similar value between multiple arc FSRT and conformal FSRT, so that we had appropriate treatment planning of FSRT for multiple arc FSRT and conformal FSRT according to tumor shape and size.

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Evaluating the usefulness of BinkieRTTM (oral positioning stent) for Head and Neck Radiotherapy (두경부암 환자 방사선 치료 시 BinkieRTTM(구강용 고정장치)에 대한 유용성 평가)

  • GyeongJin Lee;SangJun Son;GyeongDal Lim;ChanYong Kim;JeHee Lee
    • The Journal of Korean Society for Radiation Therapy
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    • v.34
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    • pp.21-30
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    • 2022
  • Purpose: The purpose of this study is to evaluate the effectiveness of oral positioning stent, the BinkieRTTM in radiation treatment for head and neck cancer patients in terms of tongue positions reproducibility, tongue doses and material properties. Materials and Methods: 24 cases using BinkieRTTM during radiation treatments were enrolled. The tongue was contoured on planning CT and CBCT images taken every 3 days during treatment, and then the DSC and center of tongue shift values were analyzed to evaluate the reproducibility of the tongue. The tongue dose was compared in terms of dose distribution when using BinkieRTTM and different type of oral stents (mouthpiece, paraffin wax). Randomly selected respective 10 patients were measured tongue doses of initial treatment plan for nasal cavity and unilateral parotid cancer. Finally, In terms of material evaluation, HU and relative electron density were identified in RTPS. Results: As a result of DSC analysis, it was 0.8 ± 0.07, skewness -0.8, kurtosis 0.61, and 95% CI was 0.79~0.82. To analyze the deviation of the central tongue shift during the treatment period, a 95% confidence interval for shift in the LR, SI, and AP directions were indicated, and a one-sample t-test for 0, which is an ideal value in the deviation(n=144). As a result of the t-test, the mean and SD in the LR and SI directions were 0.01 ± 0.14 cm (p→.05), 0.03 ± 0.25 cm (p→.05), and -0.08 ± 0.25 cm (p ←.05) in the AP direction. In the case of unilateral parotid cancer patients, the Dmean to the tongue of patients using BinkieRTTM was 16.92% ± 3.58% compared to the prescribed dose, and 23.99% ± 10.86% of patients with Paraffin Wax, indicating that the tongue dose was relatively lower when using BinkieRTTM (p←.05). On the other hand, among nasal cavity cancer patients, the Dmean of tongue dose for patients who used BinkieRTTM was 4.4% ± 5.6%, and for those who used mouthpiece, 5.9% ± 6.8%, but it was not statistically significant (p→.05). The relative electron density of Paraffin Wax, BinkieRTTM and Putty is 0.94, 0.99, 1.26 and the mass density is 0.95, 0.99 and 1.32 (g/cc), Transmission Factor is 0.99, 0.98, 0.96 respectively. Conclusion: The result of the tongue DSC analysis over the treatment period was about 0.8 and Deviation of the center of tongue shifts were within 0.2 cm, the reproducibility was more likely excellent. In the case of unilateral head and neck cancer patients, it was found that the use of BinkieRTTM rather than Paraffin Wax or Putty can reduce the unnecessary dose irradiated to the tongue. This study might be useful to understand of BinkieRTTM's properties and advantages. And also it could be another considered option as oral stent to keep the reproducibility of tongue and reducing dose during head and neck radiation treatments.

IMRT 위한 MLC QA Device 제작

  • 심재구;주상규;박영환
    • The Journal of Korean Society for Radiation Therapy
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    • v.13 no.1
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    • pp.47-50
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    • 2001
  • Purpose : 체내에서 optimal한 dose distribution을 얻기 위해 도입된 IMRT를 시행할 때 사용하는 MLC는 기계특성상 장기적인 check와 교정을 요한다. 또한 MLC는 static하지 않고 dynamic하기 때문에 leaf position의 실제 위치가 매우 중요하다. MLC QA를 위해 QA 소요시간 및 노력이 많이 MLC position check 요구되는 불편이 있어, 삼성서울 병원에서 필름을 이용한 MLC position check device를 제작하여 간편하게 사용하고 그 우수성에 대해 결과를 보고하고자 한다. Materials and Method : MLC position을 check하기위해 사각형 의 device(acryl:$40{\times}40{\times}5cm$)를 제작하였다. position check device의 정확도를 위해 표면에 real scale 표시용으로 Pb marker를 2cm 간격으로 부착하였다. MLC QA film은 마주보는 (opposite) MLC leaf의 간격이 4mm로 set up한 상태에서 double exposure하여 marker를 이용하여 오차를 분석하였다. MLC position check device의 효율성을 평가하기위해 6MV photon으로 10번 반복 실험을 실시하여 MLC leaf의 평균오차를 조사하고 조사에 걸린 시간을 비교하여 유용성을 평가하였다. Results : 실험결과 MLC leaf의 평균오차를 조사하고 조사에 걸린 시간을 비교하여 유용성을 평가하였다. 범위는 1.45mm였고, 최소 오차는 0.34mm로 나타났다. 1회 조사에 걸린 시간은 평균적으로 약 30분 정도 소요되었다. MLC position check device의 효율성을 평가한 결과오차의 반복성은 관찰되지 않았다. Conclusion : MLC leaf position의 정기적인 check와 교정을 위해 본원에서는 주1회 정기 position error를 check하고 있으며, 평균 월1회 교정을 한다. 본 실험을 통해 MLC position check device를 사용하여 leaf 오차가 2mm이하의 만족할 만한 결과를 얻었다. 또한 MLC position check device를 사용하면 짧은 시간에 모든 leaf의 position error를 쉽게 측정할 수 있고 한 장의 필름으로 모든 결과를 평가할 수 있어 경제성 및 업무의 효율성도 높일 수 있었다.

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A study on the BAC pilot plant in the Duk-san water works (덕산(德山) 정수장(淨水場)에서의 BAC Pilot plant에 관한 연구(硏究))

  • Lee, Sang-Bong;Kim, Dong-Youn;Lim, Jung-A;Lee, Won-Gwon
    • Journal of Korean Society of Water and Wastewater
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    • v.9 no.2
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    • pp.97-107
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    • 1995
  • Today a conventional water treatment system has many problems. The ozone/GAC process, sometimes termed Biological Activated Carbon(BAC), appeared to be effective for the removal of soluble organic matters in the drinking water. The water quality of Nak-dong river in Pusan, generally shows BDOC 30-40% and NBDOC 60-70%. The pilot plant installed at the Duk-san water works that was been largest treatability(1,650,000ton/day) in Pusan. A experimental water in the pilot plant made use of the water after sand-filteration. Following results are drawn from this study. Initial adsorption velocity($DOC/DOC_o/T$) in the pure adsorption of GAG had a 0.0225, it's velocity changed to 0.006 after ozone added and the optimum ozone dose ranged of $1.4-2.0mgO_3/L$. A experimental water in the pilot plant composed with humic material(78%). Humic material composed with humic acid(20%) and fulvic acid(56%), and it's rate changed to 18 and 50% respectively after ozone added. DOC constantly decreased in the EBCTs and removal efficieny in the 15min of EBCT was 45-50%. It showed the largest removal rate of BDOC in the EBCT 5 and among the season, characteristics of removal varied. The HPC distributed over $10^6-10^7CFU/cm^3$ in the bed depth and among the season, distribution of HPC were differential.

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Remote Visualization of Radiation Information based on small Semiconductor Sensor Modules (소형 반도체 센서모듈 기반 방사선정보 원격 가시화기술 연구)

  • Lee, Nam-Ho;Hwang, Young-Gwan;Heu, Yong-Suk
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.876-879
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    • 2012
  • In this paper we studied the radiation detection technology which described the radiation level distribution in high radiation area with remotely and safely. The designed radiation mapping system was composed of radiation nodes and radiation station. The radiation nodes could sense the radiation dose values with pMOSFET radiation sensors and transmit them to the radiation station. At the radiation station the received radiation values were merged with a geometric information and visualized at the virtual graphic location. For the functional verification of the above system, we attached the radiation nodes to each corner in our laboratory, executed the mapping tests, and confirmed the designed functions finally.

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A Study on Radiation Risk Recognition Aided System Visualizing Risk Information by CG

  • Katagiri, M.;Tuzuki, Y.;Sawamura, S.;Aoki, Y.
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.425-428
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    • 2002
  • The technology of Computer Graphics (CG) has been in great progress for almost 20 years and has proven to be a valuable tool for a broad variety of fields, including nuclear engineering. To work in any hazardous environment for example radiation field is particularly challenging because the danger is not always visually apparent. In this study as the application of CG to nuclear engineering field, we proposed to develop a radiation risk recognition aided system in which various radiation information; radiation risks, radiation distribution, hazard information and so on, were visualized by CG. The system used the server and client system. In the server there were two parts; one (main-server) was the database part having various data and the other (sub-server) was the visualization part visualizing the human phantom by POV-Ray. In the client there was the input and output part. The outputs from the system were various radiation information represented by coloring, circle graph and line graph intuitionally. The system is useful for a broad range of activities including radiation protection, radiation management, dose minimization, and demonstration to the public.

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Improvement of Quality Stability of Red Ginseng by Gamma Irradiation (홍삼의 품질안정성 향상을 위한 감마선의 이용)

  • 권중호;변명우;장석도;이광승
    • Food Science and Preservation
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    • v.6 no.1
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    • pp.23-28
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    • 1999
  • Commercial red ginseng, which was manufactured for the past 6 years, showed a microbial level of 2.0${\times}$10\ulcorner to 7.2${\times}$10\ulcorner CFU/g of total aerobic bacteria and molds. The moisture content of commercial products was ranged from 13.54 to 17.26%, which were higher than that of the product standard, 14%. Irradiation of red ginseng at 2.5 kGy resulted in the reduction of microorganisms contaminated to below the detectable level. Irradiation prevented mold growth on red ginseng during storage at RH 90% and 25$^{\circ}C$; molds were found at the 72nd day after storage in 2.5 kGy-irradiated sample, while 41st day in the nonirradiated control. At this point of time, irradiated samples showed an increased level of moisture content required for mold growth, 22.2% in 2.5 kGy group and 21.5% in control group. Based on the above results, microbiological qualities of red ginseng could be effectively improved by the optimum dose of irradiation, which was expected to secure the quality stability of red ginseng during distribution under the high-moistured conditions.

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Effect of Administration of Sodium Carboxymethylcellulose and Dextran on Prevention of Adhesion Formation on Uterus and Embryo Collection in Rabbits (Sodium Carboxymethylcellulose 및 Dextran의 투여가 토끼 자궁의 유착방지와 수정란에 미치는 영향)

  • 이효종;강태영;윤희준;최민철
    • Journal of Veterinary Clinics
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    • v.13 no.2
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    • pp.144-148
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    • 1996
  • The effectiveness of sodium carboxymethylcellulose (SCMC) and deztran in the prevention of adhesion formation on the uterus and embryo collection in rabbits was elucidated. Following induction of adhesion on uterus and uterine horns by abrasion and retrograde flushing of embryos in gonadotropins primed rabbits, the solutions of saline (for control), 1% SCMC, 10% dextran and a synthetic solution of 1% SCNC and 10% dextran in saline were infused in the abdominal cavity at the dose of 5 ml/kg of body weight. The average percentage of adhesion was 11.1, 28.6, 41.7 and 73.3% in the rabbits infused with the synthetic, 1% SCMC, 10% dextran and saline solutions, respectively. The synthetic solution was more effective than other solutions in the rabbits. The average number and recovery rate of embryos were significantly (P<0.01) higher in the synthetic solution group than 1% SCMC, 10% dextran or saline solution groups. Among the collected embryos in the groups, the distribution of the normal embryos was higher in the synthetic solution group (99%) and the 10% dextran solution group (95.7%) than the 1% SCMC solution group (78.4%) and saline (66.2%). Theretore, a synthetic solution which is combined with 1% SCMC and 10% deztran in saline can be effectively used for the prevention of adhesion formation after uterine surgery and embryo collection.

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Cheonggi-san Inhibits Atopy Dermatitis in NC/Nga Mouse through Regulation of iNOS mRNA Expresssion & NO production (청기산(淸肌散)의 iNOS 발현과 NO 생성 억제가 NC/Nga 생쥐의 아토피 피부염에 미치는 영향)

  • Ahn, Sang-Hyun;Kim, Ho-Hyun;Kim, Jin-Taek
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.5
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    • pp.1092-1098
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    • 2007
  • Inducible nitric oxide synthase (iNOS) are important inflammation enzyme and severe up-nitric oxide (NO) production by this enzyme has been intricate with pathogenesis of atopy dermatitis. The present study was designed in order to determine whether Cheonggi-san could inhibit atopy dermatitis through modulation of iNOS mRNA expression and NO production. We found that iNOS mRNA expression and NO production in RAW 264.7 macrophages stimulated with lipopolysaccharide dose-dependantly decreased by Cheonggi-san extract treatment (0.5 - 2.0 mg/ml). The distribution of iNOS positive reacted cell in NC/Nga mice with atopy dermatitis were decreased by Cheonggi-san extract treatment (2.5 ml/kg/day) and apoptosis were increased. These data likely indicate that Cheonggi-san may act as inflammatory regulator for atopy dermatitis and may be possible to develop useful agent for chemoprevention of NO intricate inflammatory diseases.