• 제목/요약/키워드: Radiation Technique

검색결과 1,274건 처리시간 0.028초

An effective patient training for deep inspiration breath hold technique of left-sided breast on computed tomography simulation procedure at King Chulalongkorn Memorial Hospital

  • Oonsiri, Puntiwa;Wisetrinthong, Metinee;Chitnok, Manatchanok;Saksornchai, Kitwadee;Suriyapee, Sivalee
    • Radiation Oncology Journal
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    • 제37권3호
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    • pp.201-206
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    • 2019
  • Purpose: To observe the effectiveness of the practical instruction sheet and the educational video for left-sided breast treatment in a patient receiving deep inspiration breath hold (DIBH) technique. Two parameters, simulation time and patient satisfaction, were assessed through the questionnaire. Methods: Two different approaches, which were the instruction sheet and educational video, were combinedly used to assist patients during DIBH procedures. The guideline was assigned at least 1 week before the simulation date. On the simulation day, patients would fill the questionnaire regarding their satisfaction with the DIBH instruction. The questionnaire was categorized into five levels: extremely satisfied to dissatisfied, sequentially. The patients were divided into four groups: not DIBH technique, DIBH without instruction materials, the DIBH with instruction sheet or educational video, and DIBH with both of instruction sheet and educational video. Results: Total number of 112 cases of left-sided breast cancer were analyzed. The simulation time during DIBH procedure significantly reduced when patients followed the instruction. There was no significant difference in simulation time on the DIBH procedures between patient compliance via instruction sheet or educational video or even following both of them. The excellent level was found at 4.6 ± 0.1 and 4.5 ± 0.1, for patients coaching via instruction sheet as well as on the educational video, respectively. Conclusion: Patient coaching before simulation could potentially reduce the lengthy time in the simulation process for DIBH technique. Practicing the DIBH technique before treatment is strongly advised.

이하선암의 술후 방사선치료시 방사선치료 방법에 따른 치료 실패 양상 분석 (Patterns of Failure According to Radiation Treatment Technique in the Parotid Gland Cancer)

  • 이상욱;이창걸;금기창;박정수;최은창;신현수;추성실;이석;조광환;서창옥;김귀언
    • 대한두경부종양학회지
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    • 제16권2호
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    • pp.167-171
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    • 2000
  • Objectives: To compare the outcomes of treatment with a focus on the effectiveness of the two primary techniques of radiation used for treating parotid gland malignancies. Materials and Methods: A retrospective analysis of 70 patients with parotid gland cancer treated between 1981-1997. Radiation was delivered through an ipsilateral field of high energy electron and photon in 37 patients(52.9%). Two wedge paired photon was used to treat in 33 patients(47.1%). The median dose was 60 Gy, typically delivered at 1.8-2.0Gy per fraction. The median follow-up times for surviving patients was 60 months. Results: The overall and disease free 5 year survival rates were 71.6% and 69.5%, respectively. Wedge paired photon and photon-electron treatment disease tree 5 year survival rates were 61.1% and 80.5%, respectively. Overall local failure rate was 18.6%. Local failure rate of wedge paired photon technique was higher than that of mixed beam technique. Late complication rate was 37.1%, but most of them were mild grade. Conclusion: Techniques of radiation were associated with local control. The technique of using an ipsilateral field encompassing the parotid bed and treated with high energy electrons often mixed photons was effective with minimal severe late toxicity. To irradiate deep sited tumors, we consider 3-D conformal treatment plan for well encompassing the target volume.

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Preliminary study of artificial intelligence-based fuel-rod pattern analysis of low-quality tomographic image of fuel assembly

  • Seong, Saerom;Choi, Sehwan;Ahn, Jae Joon;Choi, Hyung-joo;Chung, Yong Hyun;You, Sei Hwan;Yeom, Yeon Soo;Choi, Hyun Joon;Min, Chul Hee
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3943-3948
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    • 2022
  • Single-photon emission computed tomography is one of the reliable pin-by-pin verification techniques for spent-fuel assemblies. One of the challenges with this technique is to increase the total fuel assembly verification speed while maintaining high verification accuracy. The aim of the present study, therefore, was to develop an artificial intelligence (AI) algorithm-based tomographic image analysis technique for partial-defect verification of fuel assemblies. With the Monte Carlo (MC) simulation technique, a tomographic image dataset consisting of 511 fuel-rod patterns of a 3 × 3 fuel assembly was generated, and with these images, the VGG16, GoogLeNet, and ResNet models were trained. According to an evaluation of these models for different training dataset sizes, the ResNet model showed 100% pattern estimation accuracy. And, based on the different tomographic image qualities, all of the models showed almost 100% pattern estimation accuracy, even for low-quality images with unrecognizable fuel patterns. This study verified that an AI model can be effectively employed for accurate and fast partial-defect verification of fuel assemblies.

X-Rays through the Looking Glass: Mobile Imaging Dosimetry and Image Quality of Suspected COVID-19 Patients

  • Schelleman, Alexandra;Boyd, Chris
    • Journal of Radiation Protection and Research
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    • 제46권3호
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    • pp.120-126
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    • 2021
  • Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks. Materials and Methods: Two exposure levels were examined, a "typical" mobile exposure of 100 kVp/1.6 mAs and a "high" exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility. Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 µGy to 67.82 µGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings. Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.

발전된 방사선 치료에 관한 고찰 (A Study for Advanced Radiation Therapy)

  • 장은성;백성민;고성진;강세식
    • 대한방사선치료학회지
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    • 제20권2호
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    • pp.115-122
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    • 2008
  • 목 적: 암 치료를 위한 방사선치료 기술은 끊임없이 발전되어 왔으며 특히, 컴퓨터와 전자기 공학의 발달과 더불어 급속하게 방사선 치료분야에서 많은 발전을 하게 되었다. 따라서 본 연구에서는 발전된 치료기술에 대한 치료 원리와 방법들을 중심으로 그 특징들을 고찰하려고 한다. 대상 및 방법: 발전된 치료기술에 관한 이론적인 고찰을 위하여 관련된 문헌조사를 실시하였으며 임상에서의 자료를 광범위하게 조사 연구하였다. 결 과: 방사선을 이용한 암에 대한 치료는 눈부신 발전을 거듭하고 있다. 과거에는 2차원적인 방법으로 방사선치료를 하였으나 현재는 3차원적인 입체조형치료, 세기변조방사선치료를 병행한 4차원적인 치료기술이 도입되었으며 이는 과거 방사선치료의 난제였던 정상조직보호와 방사선에 의한 합병증 해결을 가능하게 하였다. 결 론: 발전된 방사선치료인 3, 4차원적 현대적 치료는 방사선치료의 목적에 부합되고 있으며 정상조직의 보호가 거의 완벽하게 이루어지고 있으며 방사선을 이용한 암 치료에 대한 평가도 다시 되어야 한다고 사료된다.

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Field-in-Field Technique을 이용한 두경부암의 접합부위 선량개선에 관한 고찰 (Field-in-Field Technique to Improve Dose Distribution in the Junction of the Field with Head & Neck Cancer)

  • 김선명;이영철;정덕양;김영범
    • 대한방사선치료학회지
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    • 제21권1호
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    • pp.17-23
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    • 2009
  • 목 적: 두경부암의 치료에 있어 상부 두경부의 양측면조사면과 하경부의 전방조사면의 접합부위에 균등한 선량을 조사하는 것은 매우 중요하다. 접합부위의 선량분포개선을 위하여 하경부 전방조사면의 치료시 Field-in-Field technique을 이용하여 부족선량(under dose)과 초과선량(over dose)으로 인한 선량불균등을 개선하고 일반치료와의 비교를 통하여 두경부암치료에 적용하고자 한다. 대상 및 방법: 상부 두경부의 양측면 조사시 빔의 확산으로 일어나는 입사점과 출사점의 선량차이를 알아보기 위하여 인체모형팬톰을 이용하였다. 인체모형팬톰을 전산화단층촬영하고 전산화치료계획에서 관심점의 선량비교를 시행하였고, 하경부 접합부위의 선량비율을 계산하여 이를 보정하였다. 조사면 접합부위의 선량분포를 알아보기 위하여 하경부의 접합부위에 저감도 필름을 놓고 일반적인 치료인 상부 두경부의 양측면조사와 하경부의 전방조사시 선량분포를 측정하였다. 또한, 상부 두경부 양측면 조사에 따른 빔의 확산을 고려한 Field-in-Field technique을 이용하여 하경부 전방조사를 할 때의 접합부위의 선량분포 차이를 측정하여 비교하였다. 접합부위의 관심점 선량을 알아보기 위하여 열형광선량계를 이용하여 인체모형팬톰내의 관심점에서의 선량변화를 비교, 분석하였다. 결 과: 전산화치료계획에서 하경부의 접합부위에 Field-in-Field technique을 적용하여 치료계획시 상부 두경부 양측면 조사와 선량합성을 한 경우 부족선량 영역의 선량이 4.7~8.65% 이상 증가하였다. 초과선량 영역의 선량도 2.75~10.45% 감소하였다. 또한, 저감도 필름을 이용한 측정에서는 부족선량영역에서 11.3% 증가, 초과선량영역에서 5.3% 감소한 것으로 나타났다. 열형광선량계를 이용한 관심점선량측정에서도 Field-in-Field technique 적용시 부족선량을 최소 7.5%에서 최대 17.6%까지 보정해주는 것으로 나타나 불균등한 선량분포를 개선할 수 있었다. 결 론: 전산화치료계획시 빔의 확산을 고려한 Field-in-Field technique을 적용하면 접합부위의 선량보정을 통해 냉점(cold spot)과 온점(hot spot)을 줄일 수 있었으며 특히, 빔의 확산에 따른 입사점의 부족선량을 보정할 수 있었다. 본 실험을 통해 Field-in-Field technique의 임상적용시 경부임파절의 저선량으로 인한 임파절전이에 대한 위험도를 감소시킬 수 있을 것으로 사료된다.

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Estimation of Earth Outgoing Longwave Radiation from Satellite Observation

  • Oh, Sung-Nam
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 1992년도 한국우주과학회보 제1권1호
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    • pp.12-12
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    • 1992
  • Results from the Earth Radiation Budget Experiment (ERBE) will help interpret the data from the operational satellite system. However, a major problem exists because a follow-on experiment to ERBE is not planned until the late 1990`s. Meanwhile, it will be necessary to provide OLR estimates from the operational satellite system. Since 1973the outgoing long wave radiation(OLR) data have been obtained by the 10#m window radiance(AVHRR) estimation technique from he observation NOAA operational satellites. However, those data have not been universall if accepted because they are estimated from the radiance in but one narrow spectral regiou. However , this type of technique has not been exploited for use with data from the ]fIRS multispectral radiometer. Since the radiance data measured by HIRS contains more: information on atmospheric variables than the AVHRR, it is a potentially better instrument for operational estimates of the OLR In this study, results from model are better flux estimates than the AVHRR, The technique is then tested by comparing simultalleous AVHRR and HIRS OLR estimations with a radiation model flux calculation froml homogeneous atmospheric scenes at the regions of desert and subtropic ocean.

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방사선 방어의 최적화 절차론 개발에 관한 연구 (A Study on the Development of Optimization Procedure for Radiological Protection)

  • 송종순
    • Journal of Radiation Protection and Research
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    • 제19권1호
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    • pp.1-11
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    • 1994
  • 방사선 방어의 최적화 수행에는 적용의 다양함 등을 고려할 때, 절차론이 반드시 필요하게 된다. 본 연구에서는 발전소 설계 단계에서의 최적화 절차론을 제시하고, 이를 피폭 저감대안의 선정 문제에 적용하였다. 의사결정 보조기법으로는 다기준 기법을 사용하였으며, 그 결과 대안의 우선순위를 결정하고, 최적화의 결과를 실제 적용하는 문제를 분석하였다. 이러한 최적화 절차론은 발전소 이외에 방사성 폐기물 관리나 방사선의 의학적 이용 둥의 분야에도 적용될 수 있다.

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