• Title/Summary/Keyword: TLD

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Application of Modified Mupit for the Recurrent Vulva Cancer in Brachytherapy

  • Kim, Jong-Sik;Jung, Chun-Young;Oh, Dong-Gyoon;Song, Ki-Won;Park, Young-Hwan
    • 대한방사선치료학회:학술대회논문집
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    • 2005.06a
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    • pp.23-26
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    • 2005
  • Introduction: To evaluate whether modified MUPIT applicator can effectively eradicate recurrent tumor in uterine cervix cancer and reduce rectal complication after complete radiation treatment. Methods and Materials: Modified MUPIT applicator basically consists of an acrylic cylinder with flexible brain applicator , an acrylic template with a predrilled array of holes that serve as guides for interstitial needles and interstitial needles. CT scan was performed to determine tumor volume and the position of interstitial needles. Modified MUPIT applicator was applied to patient in operation room and the accuracy for position of interstitial needles in tumor volume was confirmed by CTscan. Brachytherapy was delivered using modified MUPIT applicator and RALS (192-Ir HDR) after calculated computer planning by orthogonal film. The daily dose was 600cGy and the total dose was delivered 3000cGy in tumor volume by BID. Rectal dose was measured by TLD at 5 points so that evaluated the risk of rectal complication. Result: The application of modified MUPIT applicator improved dramatically dose distributions in tumor volume and follow-up of 3 month for this patient was clinically partial response without normal tissue complication, Rectal dose was measured 34.1cGy, 57.1cGy, 103.8cGy, 162.7cGy, 165.7cGy at each points, especially the rectal dose including previous EBRT and ICR was 34.1cGy, 57.1cGy Conclusion: Patients with locally recurrent tumor in uterine cervix cancer treated with modified MIUPIT applicator can expect reasonable rates of local control. The advantages of the system are the fixed geometry Provided by the template and cylinders, and improved dose distributions in irregular tumor volume without rectal complication

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Radon Measurement by Alpha Particle Track Method (Alpha 입자비적법(粒子飛跡法)에 의(依)한 Radon 측정(測定))

  • Kang, Yung-Ho;Park, Jang-Sick;Kim, Do-Sung
    • Journal of Radiation Protection and Research
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    • v.7 no.1
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    • pp.17-22
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    • 1982
  • Measurement of the radon concentration close to the ground surface can be used in search of environmental radiation for human safety, exploration for uranium, premonitory signals from earthquakes. We can detect radons in soil gas by alpha particle track method using the plastic track detectors, cellulose nitrate (LR115-Type 2 and CA80-15, Kodak $Path\'{e}$) and CR-39. For present works, radon cups having these detectors were made in our laboratory and their conversion factor was determined. A typical conversion factor was $1tr/cm^2{\cdot}30days=1.2{\times}10^{-2}pCi/l$. In the radon cups, some of $CaSO_4$ were used as desiccant for reducing the moisture effects on plastic track detectors. With these radon cups, underground radon concentrations of Kyungpook area were measured. Average radon concentration in Daegu from Jan. 1981 to Feb. 1982 was 39.7pCi/l. From Aug. 1981 to Feb. 1982, average radon concentrations of Daegu, Angang, Kyungju, Pohang, Chungha, and Andong were 31.8pCi/l, 124.5pCi/l, 127.0pCi/l, 79.1pCi/l, 144.4pCi/l, and 70.9pCi/l, respectively. The results were compared with the environmental radiation measured by TLD method.

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The absorbed doses from each exposure program of the Orthopos$\textregistered$ panoramic machine (Orthopos$\textregistered$ 파노라마방사선촬영기의 각종 프로그램에 따른 흡수선량)

  • Choi Soon-Chul;Lee Sul-Mi
    • Imaging Science in Dentistry
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    • v.31 no.4
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    • pp.215-219
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    • 2001
  • Purpose: The objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with 16 imaging programs available on the Orthopos/sup (R)/ panoramic machine. Materials and Methods: A Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor. the maxillary sinus, the brain, the mandibular body, the mandibular ramus. the 2nd cervical spine and the skin over TMJ area. Results : The overall absorbed doses with imaging programs available on the Orthopos/sup (R)/ panoramic machine were much less than that of standard program (program 1) except program 8, 11, and 16. Generally, the absorbed doses to the bone marrow of the mandibular ramus and the parotid gland were high, but the absorbed doses to the bone marrow in the mandibular body, brain, maxillary sinus, and, especially, the thyroid gland were very low. Conclusion : The modified imaging programs available on the Orthopos/sup (R)/ panoramic machine can be effectively used in aspect of radiation protection.

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Geant4-DICOM Interface-based Monte Carlo Simulation to Assess Dose Distributions inside the Human Body during X-Ray Irradiation

  • Kim, Sang-Tae
    • International Journal of Contents
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    • v.8 no.2
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    • pp.52-59
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    • 2012
  • This study uses digital imaging and communications in medicine (DICOM) files acquired after CT scan to obtain the absorbed dose distribution inside the body by using the patient's actual anatomical data; uses geometry and tracking (Geant)4 as a way to obtain the accurate absorbed dose distribution inside the body. This method is easier to establish the radioprotection plan through estimating the absorbed dose distribution inside the body compared to the evaluation of absorbed dose using thermo-luminescence dosimeter (TLD) with inferior reliability and accuracy because many variables act on result values with respect to the evaluation of the patient's absorbed dose distribution in diagnostic imaging and the evaluation of absorbed dose using phantom; can contribute to improving reliability accuracy and reproducibility; it makes significance in that it can implement the actual patient's absorbed dose distribution, not just mere estimation using mathematical phantom or humanoid phantom. When comparing the absorbed dose in polymethly methacrylate (PMMA) phantom measured in metal oxide semiconductor field effect transistor (MOSFET) dosimeter for verification of Geant4 and the result of Geant4 simulation, there was $0.46{\pm}4.69%$ ($15{\times}15cm^2$), and $-0.75{\pm}5.19%$ ($20{\times}20cm^2$) difference according to the depth. This study, through the simulation by means of Geant4, suggests a new way to calculate the actual dose of radiation exposure of patients through DICOM interface.

Development of Moving Objects Recognition and Tracking System on 360 Degree Panorama (360도 영상에서 이동 물체 감지 및 추적 시스템의 개발)

  • Ko, Kwang-Man;Joo, Su-Chong
    • Journal of Korea Multimedia Society
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    • v.21 no.2
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    • pp.289-299
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    • 2018
  • The 360 degree panoramas are picture of a wide range of images on one screen, so we can see a fairly wide range at a time. In particular, cylinderical panoramas are the most widely used spherical image, and its left and right viewing angles reach 360 degree, so you can observe front, rear, left, and right at once. Using 360 degree panorama, all directions can be monitored at the same time, so all directions can be effectively monitored compared to other methods. In this paper, we develop a system to recognize and track the movement of moving objects on a 360 degree panorama, and then present and verify the experimental results. For this goals, first, we developed a system to recognize moving objects in 360 degree panorama using DoF(Difference of Frame) algorithm. Second, based on the TLD algorithm, we developed an application that can track a specific single moving object in a 360 degree panorama and presented the experimental results.

Dose Distribution in the Brain in Radiotherapy of Whole Brain (전뇌조사시(全腦照射時) 뇌(腦)에 있어서의 선량분포(線量分布))

  • Kang, Wee Saing;Ha, Sung Whan;Park, Charn Il
    • Radiation Oncology Journal
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    • v.1 no.1
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    • pp.37-40
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    • 1983
  • Whole brain irradiation is one mode in the treatment of brain cancer and brain metastasis, but it might cause brain injury such as brain necrosis. It has been studied whether the dose distribution could be a cause of brain injury. The dose distribution in whole brain irradiated by Co-60 beam has been measured by means of calibrated TLD chips inserted in the brain of Humanoid phantom. The following results were obtained. 1. Dose distribution on each transverse section of the brain was uniform. 2. On the midsagital plane of the brain, the dose was highest in upper portion and lowest in lower portion, varying 8 from 104% to 90%. 3. When the radiation field includes free space of 2cm or more width out of the head, the dose distribution in the whole brain is almost independent of the field width. 4. It is important to determine adequate shielding area and to set shielding block exactly in repetition of treatment.

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Analysis of Trip Length Distribution between Commodity-Based Model and Truck Trip-Based Model in Seoul Metropolitan Area (화물기반모형과 트럭통행기반모형의 통행거리분포 분석에 관한 연구)

  • 권혁구;김건영;임홍상;강경우
    • Journal of Korean Society of Transportation
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    • v.20 no.2
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    • pp.125-134
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    • 2002
  • 도시화물수요예측모형에는 화물기반모형과 트럭통행기반모형이 있는데 화물기반모형은 화물체계가 기본적으로 화물운송과 관계가 있다는 개념에 기초를 두고 있으며, 차량이 아닌 화물의 움직임을 주요 분석대상으로 삼고 있다. 반면에, 트럭통행기반모형은 집합화된 독립변수를 이용하여 각 죤(Zone)에 유·출입하는 트럭의 통행을 분석하는 것이다. 본 연구의 목적은 트럭통행기반모형의 O-D 추정시 화물통행과 트럭통행 사이의 관계식을 산출하고 이를 설명할 수 있는 통행거리분포함수(Trip Length Distribution : TLD)를 추정함에 있다. 본 연구의 자료는 교통개발연구원에서 수행한 '서울시 물류조사 및 물류종합계획수립구상(1998)'의 화물 물동량 조사 자료를 이용하였으며, 이를 통해 통행거리분포에 따르는 화물 및 차량의 비율을 함수로서 나타내었다. 본 연구를 통하여 트럭통행기반모형에서 트럭통행거리분포를 이용하여 화물기반모형에서 도출할 수 있는 화물의 통행거리분포를 추정할 수 있었으며, 또한 각각의 통행거리분포는 감마분포를 이용하여 함수식으로 도출하고 상기한 두 가지 분포모형을 하나의 관계식을 통해 재산정할 수 있는 이론적인 틀을 제공하였다는 데 의의가 있다고 하겠다. 트럭통행거리분포, 화물통행거리분포 모두 통계적인 검증을 통해 적합한 것으로 분석되었으며, 전체화물의 통행거리분포와 매개함수를 통해 재산정된 모형의 결과 값 또한 통계적으로 유의하였다. 품목별 적용에서는 잡공업품과 화학공업품은 본 연구의 매개함수식을 통해 화물거리분포 모형이 적합하였으나 금속공업 품과 경공업품은 다소 차이가 있는 것으로 분석되었다.

A Study on the Dose Analysis of Pottery Shards by Thermoluminescence Dating Method (TL 연대측정법을 이용한 토기 시편의 선량 분석)

  • Shin, Hyun-Sang
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.558-564
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    • 1999
  • A method for measuring archaeological dose of Packjae pottery shards using thermoluminescence dosimetry(TLD) has been studied. TL measurement has been achieved using quartz crystals in the size range of 90 to $125{\mu}m$ diameter extracted from the pottery shards. The stable temperature region of the TL glow curve which is devoid of anomalous fading components was identified by the plateau test and found to exist from 265 to $300^{\circ}C$. The archaeological dose of the pottery shards was estimated to be 7.43 Gy using the dose calibration curves obtained from sequential irradiation of $^{137}Cs$ gamma source to the samples and TL measurement of natural samples.

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A Trial of 6 MV Linear Accelerator Radiation Therapy (RT) for Breast Cancer (6 MV 선형가속기를 사용한 유방암 치료)

  • Lee Guy Won;Park Ju Seon;Kim Geol;Yoon Sei Chul
    • The Journal of Korean Society for Radiation Therapy
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    • v.1 no.1
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    • pp.37-42
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    • 1985
  • Radiation Therapy(RT) has been used in the treatment of breast cancer for over 80 years. Technically, it should include a part or all of such areas as chest wall or breast, axilla, internal mammary nodes(IM) and supraclavicular nodes (SCL). Authors tried three-field technique for the treatment of breast cancer using 6 MV linear accelerator, exclusively the department of Radiology, Kang-Nam St. Mary's Hospital, at Catholic Medical College. The field junction was checked by a phantom study and radiation doses measured by film densitometry and TLD. The 3 fields we used in this study were two isocentric opposing tangential fields encompassing the breast, chest wall and occasionally IM and one single anterior field encompassing the axilla and SCL. Using appropriate beam blocks and blouses, we were able to avoid unwanted intrinsic divergency of photon beam. Blocking also enabled us to set-up precise radiation field with ease.

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The Retrieval of Abnormal TL Glow Curves Using Modified Glow Curve Analysis Method

  • Lee, Sang-Yoon;Lee, Kun-Jai;Kim, Jang-Lyul;Chang, Si-Young
    • Nuclear Engineering and Technology
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    • v.29 no.5
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    • pp.385-392
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    • 1997
  • The shape of TL glow curve is a useful indicator for assurance of correct reading of the personal dosimeter. Since the reading procedure of TLD is irreversible, however, an analytic remedy should be considered to procure reliable dosimetric information for the readings with irregular glow con shape. In this study, kinetic trapping parameters of CaSO$_4$ : Dy Teflon personal dosimeter(Teledyne PB-6A) were analyzed by Halperin and Braner's model for general-order kinetics. From these kinetic tapping parameters, we also developed a simple procedure to retrieve the dosimetric information from abnormally distorted glow curves. The computerized glow curve deconvolution(CGCD) fitting of the reference glow curve with kinetic parameters from this study yields relative errors of about 5% from the expected integral. It was also found that the glow curve remedial procedure developed could retrieve the distorted TL glow curves within ewer ranges of 1575. With the glow curve retrieval techniques, doses incurred by gamma radiation can now be successfully re-constructed for the CaSO$_4$ : Dy Teflon dosimeter resulting abnormal glow curves.

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