• Title, Summary, Keyword: indicator of radiation

Search Result 108, Processing Time 0.033 seconds

Development of a Qualitative Dose Indicator for Gamma Radiation Using Lyophilized Deinococcus

  • Lim, Sangyong;Song, Dusup;Joe, Minho;Kim, Dongho
    • Journal of Microbiology and Biotechnology
    • /
    • v.22 no.9
    • /
    • pp.1296-1300
    • /
    • 2012
  • The feasibility of using Deinococcus showing strong resistance to both desiccation and ionizing radiation as a dose indicator of gamma radiation exposure was evaluated. Three Deinococcus strains having different levels of radiation resistance, Deinococcus radiodurans (DRD), Deinococcus radiopugnans (DRP), and the DRD pprI mutant (DRM), were selected to develop an appropriate dose indicator for a broad range of exposures. DRD, DRP, and DRM cultures with different numbers of cells [${\sim}10^7$ to $10^3$ colony forming units (CFU)/$100{\mu}l$] were lyophilized and subjected to various doses of gamma radiation to determine a critical dose that inhibited bacterial growth completely. Finally, a combination of DRD at ${\sim}10^7$ and ${\sim}10^6$ CFU, DRP at ${\sim}10^5$ CFU, and DRM at ${\sim}10^4$ CFU successfully indicated exposure to 5, 10, 20, and 30 kGy of gamma radiation, respectively. This study shows the possibility of developing a qualitative indicator of radiation exposure using Deinococcus.

Daily check device manufacture and efficiency Evaluation for daily Q.A (일일 정도관리를 위한 Daily check device 의 제작 및 효율성 평가)

  • Kim Chan Yong;Je Yeong Wan;Lee Je Hui;Park Heung Deuk
    • 대한방사선치료학회:학술대회논문집
    • /
    • /
    • pp.19-22
    • /
    • 2005
  • Introduction: Daily Q.A is the important step which must be preceded in a radiation treatment. Specially, radiation output measurement and laser alignment, SSD indicator related to a patient set-up recurrence must be confirmed for a reasonable radiation treatment. Daily Q.A proceeds correctness and a prompt way, and needs an objective measurement basis. Manufacture of the device which can facilitate confirmation of output measurement and appliances check at one time was requested. Methods and Materials: Produced the phantom formal daily check device which can confirm a lot of appliances check (output measurement and laser alignment, field size, SSD indicator) with one time of set up at a time, and measurement observed a linear accelerator (4 machine) for four months and evaluated efficiency. Result: We were able to confirm an laser alignment, field size, SSD indicator check at the same time, and out put measurement was possible with the same set up, so daily Q.A time was reduced, and were able to confirm an objective basis about each item measurement. As a result of having measured for four months, output measurement within ${\pm}\;2\%$, and measured laser alignment, field size, SSD indicator in range within ${\pm}\;1mm$. Conclusion: We can enforce output measurement and appliances check conveniently and time was reduced and was able to raise efficiency of business. We were able to bring n cost reduction by substitution expensive commercialized equipment. Further It is necessary to makes a product as strong and slight materials, and improve convenience of use.

  • PDF

Advanced Treatment Planning Method for Gamma Knife Radiosurgery of Cerebral Arteriovenous Malformations (뇌동정맥기형의 감마나이프 방사선 수술 -치료 계획 방법의 개선을 중심으로-)

  • Jang Geon-Ho;Lim Young Jin;Hong Seong Eon;Leem Won
    • Radiation Oncology Journal
    • /
    • v.13 no.1
    • /
    • pp.87-94
    • /
    • 1995
  • Since March 1992, total 200 patients who visited our hospital as functional or organic lesions of central nervous system were treated by gamma knife stereotactic radiosurgery for 27 months. Thirty-nine patients of total cases was diagnosed as cerebral arteriovenous malformation. The rate of magnification on X-ray film was reduced by cutting fixation adaptor from 1.0 to below 1.45 times. In order to treat the deep- and lateral-seated cerebral arteriovenous malformation, we slightly modified the angiographic indicator, the commercial Leksell system, by cutting each inner sides about 5mm, We performed the more distinction of the scales by adapting 0.5mm or 1mm copper filter to angiographic indicator. The center point of indicator(X=100mm, Y=100mm, Z=100mm) is corrected by adjusting scales of X-, Y-, Z-axis to each inner 100 and outer 100 point within 1-2mm by repeated exposure of X-ray on films in trial-and-errors. We have developed the 'GKANGIO' programed as the Fortran-77 in Microvax - 3100, which can save treatment planning time and perform accurate pretreatment planning using the theoretical target metrix center. The theoretical description of the simplified method is presented for the reduction of experimental and numerical errors in treatment planning of radiosurgery.

  • PDF

Manufacture of Daily Check Device and Efficiency Evaluation for Daily Q.A (일일 정도관리를 위한 Daily Check Device의 제작 및 효율성 평가)

  • Kim Chan-Yong;Jae Young-Wan;Park Heung-Deuk;Lee Jae-Hee
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.17 no.2
    • /
    • pp.105-111
    • /
    • 2005
  • Purpose : Daily Q.A is the important step which must be preceded in a radiation treatment. Specially, radiation output measurement and laser alignment, SSD indicator related to a patient set-up recurrence must be confirmed for a reasonable radiation treatment. Daily Q.A proceeds correctness and a prompt way, and needs an objective measurement basis. Manufacture of the device which can facilitate confirmation of output measurement and appliances check at one time was requested. Materials and Methods : Produced the phantom formal daily check device which can confirm a lot of appliances check (output measurement and laser alignment. field size, SSD indicator) with one time of set up at a time, and measurement observed a linear accelerator (4 machine) for four months and evaluated efficiency. Results : We were able to confirm an laser alignment, field size, SSD indicator check at the same time, and out put measurement was possible with the same set up, so daily Q.A time was reduced, and we were able to confirm an objective basis about each item measurement. As a result of having measured for four months, output measurement within ${\pm}2%$, and measured laser alignment, field size, SSD indicator in range within ${\pm}1mm$. Conclusion : We can enforce output measurement and appliances check conveniently, and time was reduced and was able to raise efficiency of business. We were able to bring a cost reduction by substitution expensive commercialized equipment. Further It is necessary to makes a product as strong and slight materials, and improve convenience of use.

  • PDF

Basic Principles of CT Dose Index and Understanding of CT Parameter for Dose Reduction Technique (CT선량지표의 원리와 선량감소 방안에 관한 연구)

  • Kim, Jung-Su;Kwon, Soon-Mu;Kim, Jung-Min
    • Journal of radiological science and technology
    • /
    • v.38 no.1
    • /
    • pp.51-61
    • /
    • 2015
  • Computed tomography(CT) using radiation have potential risks. All medical radiographic examinations should require the justification of medical imaging examinations and optimization of the image quality and radiation exposure. The CT examination was higher radiation dose then general radiography. Especially pediatric CT examinations need to great caution of radiation risk. Because of pediatric patient was more sensitive of radiation exposure. Therefore, physician should consider the knowledge of CT radiation exposure indicator information for reduce a needless radiation exposure. This article was aim to understanding of CT exposure indicator, size-specific dose estimates by American Association of Physicists in Medicine (AAPM) report 204, XR 25 and understanding of CT dose reduction technique.

Economic Scale of Radiation Application in Japan

  • Kume, Tamikazu
    • Journal of Radiation Industry
    • /
    • v.5 no.3
    • /
    • pp.191-196
    • /
    • 2011
  • The economic scale of nuclear application is a good indicator to show how the radiation technology is useful and contribute to improve public welfare and living standard. Recent research in Japan shows that the economic scale of nuclear field was 4,112 B¥ for radiation application(46%) and 4,741 B¥ for nuclear energy (54%) playing a role of "two wheels of one cart" in nuclear field and the total 8,853 B¥ constitutes 1.8% of gross domestic products (GDP). The radiation application consisted of 2,295 B¥ (56%) in industry (semiconductor, sterilization, nondestructive testing, radiation processing of tires, etc.), 1,538 B¥ (37%) in medicine (therapy and diagnosis such as X-ray, nuclear medicine, computed tomography, etc.) and 279 B¥ (7%) in agriculture (mutation breeding, food irradiation, sterile insect technique, etc.). Radiation application by ${\gamma}$-ray, electron beam and ion beam is steadily increasing in Japan.

Bicyclic Derivatives of Aziridine - Materials for New Indicators of Radiation

  • Chebanov, V.A.;Zbruyev, A.I.;Desenko, S.M.;Doroshenko, A.O.;Vaschenko, V.V.
    • Journal of Radiation Protection and Research
    • /
    • v.30 no.1
    • /
    • pp.31-34
    • /
    • 2005
  • The article is devoted to the study of some hi-and tricyclic derivatives of aziridine as materials lot newindicators of ionizing radiation. To create high sensitive materials some aspects of photo induced ring opening processes in aziridine derivatives in ethanol solutions and in polymeric matrix were studied and two steps character of the processes investigated was established. Two types of radioindicators were suggested and preliminary tested. The new way of synthesis of radiochromic derivatives of aziridine was developed and series of target compounds synthesized.

New methods for optical distance indicator and gantry angle quality control tests in medical linear accelerators: image processing by using a 3D phantom

  • Shandiz, Mahdi Heravian;Layen, Ghorban Safaeian;Anvari, Kazem;Khalilzadeh, Mohammadmahdi
    • Radiation Oncology Journal
    • /
    • v.33 no.1
    • /
    • pp.42-49
    • /
    • 2015
  • Purpose: In order to keep the acceptable level of the radiation oncology linear accelerators, it is necessary to apply a reliable quality assurance (QA) program. Materials and Methods: The QA protocols, published by authoritative organizations, such as the American Association of Physicists in Medicine (AAPM), determine the quality control (QC) tests which should be performed on the medical linear accelerators and the threshold levels for each test. The purpose of this study is to increase the accuracy and precision of the selected QC tests in order to increase the quality of treatment and also increase the speed of the tests to convince the crowded centers to start a reliable QA program. A new method has been developed for two of the QC tests; optical distance indicator (ODI) QC test as a daily test and gantry angle QC test as a monthly test. This method uses an image processing approach utilizing the snapshots taken by the CCD camera to measure the source to surface distance (SSD) and gantry angle. Results: The new method of ODI QC test has an accuracy of 99.95% with a standard deviation of 0.061 cm and the new method for gantry angle QC has a precision of $0.43^{\circ}$. The automated proposed method which is used for both ODI and gantry angle QC tests, contains highly accurate and precise results which are objective and the human-caused errors have no effect on the results. Conclusion: The results show that they are in the acceptable range for both of the QC tests, according to AAPM task group 142.

The Non-Enzymatic Browning Reaction Occurred by Gamma Irradiation in Sugar-Lysine Aqueous Model Solution (당-Lysine 모델 수용액을 이용한 감마선 조사에 의한 비효소적 갈변반응 연구)

  • Lee, Ju-Woon;Oh, Sang-Hee;Kim, Jae-Hun;Byun, Eui-Hong;Kim, Mee-Ree;Kim, Kwan-Soo;Lee, Hyeon-Ja;Byun, Myung-Woo
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.35 no.5
    • /
    • pp.583-587
    • /
    • 2006
  • Aqueous solutions of sugar alone or in the presence of lysine were gamma irradiated at 0, 5, 10, 20 and 30 kGy at room temperature. Absorbances at 284 nm as an indicator of intermediate stage of non -enzymatic browning reaction increased with irradiation dose in both the solution of sugar or lysine alone and sugar-lysine mixed solution. Absorbances at 420 nm as indicator of browning increased in the irradiated sugar-lysine mixed solutions although no browning was observed in the irradiated solution of sugar or lysine alone. The degree of browning of the irradiated sugar-lysine mixed solution increased with irradiation dose and was dependent on the type of sugar. For sugar-lysine mixed solution irradiated at 30 kGy, the browning had the following order of intensity: sucrose>fructose>arabinose>xylose>glucose. However, the sugar loss of irradiated sugar lysine mixed solution had a following order of intensity: glucose>fructose>sucrose>xylose>arabinose. The reducing power of the non-reducing sugar, sucrose, was produced by gamma irradiation. The present results indicated that gamma irradiation leads to a non-enzymatic browning reaction (carbonyl-amine reaction) in an aqueous system.

Combined Effects of Radiation and Ultrasound on Embryonic Development in Mice (ICR 마우스의 태아(胎兒)에 대(對)한 방사선(放射線)과 초음파(超音波)의 공동효과(共同效果)에 관한 실험적(實驗的) 검토(檢討))

  • Gu, Yeun-Hwa
    • Journal of radiological science and technology
    • /
    • v.14 no.2
    • /
    • pp.37-44
    • /
    • 1991
  • The combined effect of radiation and ultrasound has been studied in mouse embryos. Radiation and/or ultrasound were adminstered to ICR mice on day 8 of gestation. Intrauterine death, gross malformation, and fetal body weight were selected as indicators of effects. Does of whole-body ${\gamma}-irradiation$ were 0.5 to 2.5 Gy and those of ultrasound were $0.5\;W/cm^2$ to $3\;W/cm^2$. Intrautrine mortality increased with increasing radiation dose ; this trend was more remarkable in combination with ultrasound. Gross malformations such as exencephaly and anophthalmia/microphthalmia appeared frequently in the fetuses treated with both radiation and ultrasound. Decreased fetal weight was observed even in mice treated with 1.5 Gy of radiation or $1\;W/cm^2$ of ultrasound. There was a linear relationship between dose and reduction of fetal weight. The fetal weight was sensitive, precise and easy-to-handle indicator for the effects of growth retardation. Intrauterine mortality and frequencies of exencephaly and anophthalmia/microphthalmia were higher than the sum of those induced by radiation and by ultrasound. The results indicatied that the combined action of radiation and ultrasound on intrauterine death and malformations was synergistic.

  • PDF