WorldWideScience

Sample records for curie dose evaluation

  1. A dose to curie conversion methodology

    International Nuclear Information System (INIS)

    Stowe, P.A.

    1987-01-01

    Development of the computer code RadCAT (Radioactive waste Classification And Tracking) has led to the development of a simple dose rate to curie content conversion methodology for containers with internally distributed radioactive material. It was determined early on that, if possible, the computerized dose rate to curie evaluation model employed in RadCAT should yield the same results as the hand method utilized and specified in plant procedures. A review of current industry practices indicated two distinct types of computational methodologies are presently in use. The most common methods are computer based calculations utilizing complex mathematical models specifically established for various containers geometries. This type of evaluation is tedious, however, and does not lend itself to repetition by hand. The second method of evaluation, therefore, is simplified expressions that sacrifice accuracy for ease of computation, and generally over estimate container curie content. To meet the aforementioned criterion current computer based models were deemed unacceptably complex and hand computational methods to be too inaccurate for serious consideration. The contact dose rate/curie content analysis methodology presented herein provides an equation that is easy to use in hand calculations yet provides accuracy equivalent to other computer based computations

  2. Marie Curie; Marie Curie

    Energy Technology Data Exchange (ETDEWEB)

    Trotereau, J.

    2011-07-01

    The legend has only retained from Marie Curie (1867-1934) the image of a hard and brilliant worker, pioneer in the radioactivity domain, and who awarded twice the Nobel Price. Behind the scientist, there is a women, Marya Salomea Sklodowska, the 'Polish', who was considered during some time as an 'alien', an 'atheistic intellectual', an 'emancipated women'. When she died alone in July 1934, after an exhausting life of labour, her funeral led to no official ceremony or speech. This small book summarizes the biography of the most famous female scientist in the world

  3. Long-term results of exclusive low-dose rate curie-therapy for a high-grade vaginal intraepithelial neoplasia

    International Nuclear Information System (INIS)

    Blanchard, P.; Monnier, L.; Dumas, I.; Azoury, F.; Mazeron, R.; Haie-Meder, C.

    2010-01-01

    The authors report the results of an exclusive low dose rate curie therapy for female patients treated for a grade 3 vaginal intraepithelial neoplasia. They reviewed the medical files of patients treated since 1983, i.e. 28 women. They analysed demographic characteristics, the clinic description of lesions, possible treatments which occurred before this high-grade vaginal intraepithelial neoplasia, possible previous history of cervical or endometrial cancer, curie therapy detailed data, presence of tumorous relapse. According to that, they conclude that a 60 Gy exclusive low- vaginal dose-rate curie-therapy is an efficient and well tolerated treatment for high-grade vaginal intraepithelial neoplasia. Short communication

  4. Madame Curie

    International Nuclear Information System (INIS)

    Curie, E.

    1988-02-01

    This biography of the scientist Maria Sklodovska-Curie in a very impressive manner tells the story of her life as a child, and later on as a young female scientist and as the wife and scientist companion of Pierre Curie. The discovery of the radium and the subsequent international reputation as a leading scientist are reported, referring in great detail to the scientific aspects and achievements. (DG) [de

  5. Pierre Curie

    International Nuclear Information System (INIS)

    Barbo, L.

    1999-01-01

    Already famous when he discovered the radioactivity with his wife Marie, Pierre Curie fell into oblivion afterward. This book describes the theoretical and experimental works of this man of genius and clears up some old stubborn legends about the man and its works. (J.S.)

  6. Clinical and dosimetric results of three-dimensional image-guided and pulsed dose rate curie-therapy in locally advanced cervical cancers

    International Nuclear Information System (INIS)

    Mazeron, R.; Gilmore, J.; Dumas, I.; Abrous-Anane, S.; Haberer, S.; Verstraet, R.; Champoudry, J.; Martinetti, F.; Morice, P.; Haie-Meller, C.

    2011-01-01

    The authors report a review of data obtained between 2004 and 2009 on 130 women who had been treated by optimized pulsed-rate curie-therapy for a locally advanced cervical cancer. Results are discussed in terms of cancer stage, treatment (with or without concomitant chemotherapy), planning method (MRI, scanography), delivered doses in the clinical target volumes, surgery, relapse occurrence and localizations, global survival probability, local control, undesirable side effects, occurrence of intestine or urinary toxicity. It appears that the association of a concomitant chemo-radiotherapy and optimized curie-therapy results in a good local-regional control and a low toxicity level. Short communication

  7. A new method of Curie depth evaluation from magnetic data: Theory

    Science.gov (United States)

    Won, I. J. (Principal Investigator)

    1981-01-01

    An approach to estimating the Curie point isotherm uses the classical Gauss method inverting a system of nonlinear equations. The method, slightly modified by a differential correction technique, directly inverts filtered Magsat data to calculate the crustal structure above the Curie depth, which is modeled as a magnetized layer of varying thickness and susceptibility. Since the depth below the layer is assumed to be nonmagnetic, the bottom of the layer is interpreted as the Curie depth. The method, once fully developed, tested, and compared with previous work by others, is to be applied to a portion of the eastern U.S. when sufficient Magsat data are accumulated for the region.

  8. Madame Curie

    CERN Document Server

    Eve, Curie

    1942-01-01

    Marie Curie is a women who changed the face of science for all time, not just because of her discovery of the radioactive element Radium and her work with it, but because of her incredible strides forward in a such a male dominated world as laboratory science at the turn of the 19th century. This is the Madame Curie many people know but here is a biography written by her daughter Eve that shows her human side, in a way that can only be viewed and admired from a family member describing her as a caring mother, devoted and passionate wife. Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce and increasingly expensive.

  9. Estimation of low-level neutron dose-equivalent rate by using extrapolation method for a curie level Am–Be neutron source

    International Nuclear Information System (INIS)

    Li, Gang; Xu, Jiayun; Zhang, Jie

    2015-01-01

    Neutron radiation protection is an important research area because of the strong radiation biological effect of neutron field. The radiation dose of neutron is closely related to the neutron energy, and the connected relationship is a complex function of energy. For the low-level neutron radiation field (e.g. the Am–Be source), the commonly used commercial neutron dosimeter cannot always reflect the low-level dose rate, which is restricted by its own sensitivity limit and measuring range. In this paper, the intensity distribution of neutron field caused by a curie level Am–Be neutron source was investigated by measuring the count rates obtained through a 3 He proportional counter at different locations around the source. The results indicate that the count rates outside of the source room are negligible compared with the count rates measured in the source room. In the source room, 3 He proportional counter and neutron dosimeter were used to measure the count rates and dose rates respectively at different distances to the source. The results indicate that both the count rates and dose rates decrease exponentially with the increasing distance, and the dose rates measured by a commercial dosimeter are in good agreement with the results calculated by the Geant4 simulation within the inherent errors recommended by ICRP and IEC. Further studies presented in this paper indicate that the low-level neutron dose equivalent rates in the source room increase exponentially with the increasing low-energy neutron count rates when the source is lifted from the shield with different radiation intensities. Based on this relationship as well as the count rates measured at larger distance to the source, the dose rates can be calculated approximately by the extrapolation method. This principle can be used to estimate the low level neutron dose values in the source room which cannot be measured directly by a commercial dosimeter. - Highlights: • The scope of the affected area for

  10. Marie Curie's heritage

    International Nuclear Information System (INIS)

    Pajot, Ph.; Schaeffer, A.; Barhelemy, P.

    2011-01-01

    This issue is almost entirely dedicated to Marie Curie. The first part gives the main steps of her life, an article draws a parallel with Lise Meitner's life, another describes the instruments Marie Curie used to measure radioactivity and a third one gives an idea of the network of scientists she integrated. The second part presents the scientific heritage of Marie Curie, first the curietherapy then medical imaging and radiocarbon dating. The third part presents other achievements and commitments of Marie Curie concerning the place of women in a modern society and the social changes trough scientific progress. (A.C.)

  11. Pierre Curie works. 2. ed.

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    One of the most important physicist of the 19th century end to the 20th century beginning, Pierre Curie has attached his name to some very important discoveries such as piezoelectricity, the Curie law, the Curie point, the Curie principle, and with Marie Curie: the discovery of radium. This re-edition of the book published two years after his death contains all the Pierre Curie publications. (A.B.)

  12. Application of the dose rate spectroscopy to the dose-to-curie conversion method using a NaI(Tl) detector

    International Nuclear Information System (INIS)

    JI, Young-Yong; Chung, Kun Ho; Kim, Chang-Jong; Kang, Mun Ja; Park, Sang Tae

    2015-01-01

    Dose rate spectroscopy is a very useful method to directly calculate the individual dose rate from the converted energy spectrum for the dose rate using the G-factor which is related to the used detector response function. A DTC conversion method for the estimation of the radioactivity based on the measured dose rate from the radioactive materials can then be modified into a simple equation using the dose rate spectroscopy. In order to make the method validation of the modified DTC conversion method, experimental verifications using a 3″φx3″ NaI(Tl) detector were conducted at the simple geometry of the point source located onto a detector and more complex geometries which mean the assay of the simulated radioactive material. In addition, the linearity about the results from the modified DTC conversion method was also estimated by increasing the distance between source positions and a detector to confirm the method validation in the energy, dose rate, and distance range of the gamma nuclides. - Highlights: • A modified DTC conversion method using the dose rate spectroscopy was established. • In-situ calibration factors were calculated from the MCNP simulation. • Radioactivities of the disk sources were accurately calculated using a modified DTC conversion method. • A modified DTC conversion method was applied to the assay of the radioactive material

  13. Marie Curie: scientific entrepreneur

    International Nuclear Information System (INIS)

    Boudia, S.

    1998-01-01

    Marie Curie is best known for her discovery of radium one hundred years ago this month, but she also worked closely with industry in developing methods to make and monitor radioactive material, as Soraya Boudia explains. One hundred years ago this month, on 28 December 1898, Pierre Curie, Marie Sklodowska-Curie and Gustave Bemont published a paper in Comptes-rendus - the journal of the French Academy of Sciences. In the paper they announced that they had discovered a new element with astonishing properties: radium. But for one of the authors, Marie Curie, the paper was more than just the result of outstanding work: it showed that a woman could succeed in what was then very much a male-dominated scientific world. Having arrived in Paris from Poland in 1891, Marie Curie became the first woman in France to obtain a PhD in physics, the first woman to win a Nobel prize and the first woman to teach at the Sorbonne. She also helped to found a new scientific discipline: the study of radioactivity. She became an icon and a role-model for other women to follow, someone who succeeded - despite many difficulties - in imposing herself on the world of science. Although Curie's life story is a familiar and well documented one, there is one side to her that is less well known: her interaction with industry. As well as training many nuclear physicists and radiochemists in her laboratory, she also became a scientific pioneer in industrial collaboration. In this article the author describes this side of Marie Curie. (UK)

  14. Marie Skoldowska Curie

    Indian Academy of Sciences (India)

    editors

    She found that for a given amount of active material, the current increased with the plate ... In the words of their daughter Eve Curie “they began ... Although it was similar to barium in its chemical properties, its chloride was less soluble in water.

  15. Population dose estimation from a hypothetical release of 2.4 x 106 curies of noble gases and 1 x 104 curies of 131I at the Three Mile Island Nuclear Station, Unit 2

    International Nuclear Information System (INIS)

    Berger, C.D.; Lane, B.H.; Cotter, S.J.; Miller, C.W.; Glandon, S.R.

    1981-09-01

    Beginning on March 28, 1979, a sequence of events occurred at the Three Mile Island Nuclear Station Unit 2 (TMINS-2) nuclear power reactor which resulted in the accidental release of approximately 2.4 x 10 6 Ci of noble gases and 13 to 15 Ci 131 I. A comprehensive study of this incident has been reported by the President's Commission on the Accident at Three Mile Island. As part of this study, the Technical Assessment Task Group for the Commission addressed a series of alternative event scenarios, including the potential for a higher release of 131 I. As a continuation of this task, this report presents the estimated collective dose to the population within 50 miles of TMINS-2 from a hypothetical release of 2.4 x 10 6 Ci of noble gases and 1 x 10 4 Ci 131 I by the methodology of atmospheric dispersion modeling and population dose estimation through the inhalation, ingestion and immersion exposure pathways

  16. Clinical and dosimetric results of three-dimensional image-guided and pulsed dose rate curie-therapy in locally advanced cervical cancers; Resultats cliniques et dosimetriques de la curietherapie de debit de dose pulse guidee par imagerie tridimensionnelle dans les cancers du col de l'uterus localement evolues

    Energy Technology Data Exchange (ETDEWEB)

    Mazeron, R.; Gilmore, J.; Dumas, I.; Abrous-Anane, S.; Haberer, S.; Verstraet, R.; Champoudry, J.; Martinetti, F.; Morice, P.; Haie-Meller, C. [Institut de cancerologie Gustave-Roussy, Villejuif (France)

    2011-10-15

    The authors report a review of data obtained between 2004 and 2009 on 130 women who had been treated by optimized pulsed-rate curie-therapy for a locally advanced cervical cancer. Results are discussed in terms of cancer stage, treatment (with or without concomitant chemotherapy), planning method (MRI, scanography), delivered doses in the clinical target volumes, surgery, relapse occurrence and localizations, global survival probability, local control, undesirable side effects, occurrence of intestine or urinary toxicity. It appears that the association of a concomitant chemo-radiotherapy and optimized curie-therapy results in a good local-regional control and a low toxicity level. Short communication

  17. Evolution of radon dose evaluation

    Directory of Open Access Journals (Sweden)

    Fujimoto Kenzo

    2004-01-01

    Full Text Available The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

  18. Curie Meitner Lamarr, indivisible

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    at CERN's Globe of Science and Innovation Directed by Sandra Schüddekopf, with Anita Zieher For over 20 years, CERN has made an effort to attract more women to scientific careers and enhance the gender balance of its workforce. In addition to structural measures, these efforts range from outreach activities for schoolgirls to participation in high-level panel discussions on the topic. Today, the CERN Diversity Office, in cooperation with the Education, Communication and Outreach group, is happy to announce a play celebrating the achievements of three exceptional women in the field of science and technology: double Nobel Prize laureate Marie Curie (1867-1934), who discovered radioactivity, Austrian-Swedish nuclear physicist Lise Meitner (1878-1968), and Viennese Hollywood actress Hedy Lamarr (1914-2000), the inventor of frequency hopping. The play &quo...

  19. Curie depth and geothermal gradient from spectral analysis of ...

    African Journals Online (AJOL)

    The resent (2009) aeromagnetic data covering lower part of Benue and upper part of Anambra basins was subjected to one dimensional spectral analysis with the aim of estimating the curie depth and subsequently evaluating both the geothermal gradient and heat flow for the area. Curie point depth estimate obtained were ...

  20. Dose gradient curve: A new tool for evaluating dose gradient.

    Science.gov (United States)

    Sung, KiHoon; Choi, Young Eun

    2018-01-01

    Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice.

  1. The light and brilliancy of Marie Curie

    International Nuclear Information System (INIS)

    Craig, P.

    1984-01-01

    The paper describes the life and work of Marie Curie, from her childhood to her death (at nearly 67 years), and including her marriage to Pierre Curie. The scientific work, by the Curies, leading to the discovery of polonium and radium is described, as well as the making of radium chloride. The importance of the Curies' work to theoretical science is briefly discussed, and the effects of radioactivity on the Curies is touched upon. (U.K.)

  2. Curie-therapy for the conservative treatment of 304 choroidal melanomas in the Catalonia Oncology Institute

    International Nuclear Information System (INIS)

    Riou, O.; Gutierrez, C.; Pera, J.; Martinez, E.; Caminal, J.M.; Modolell, I.; Navarro, V.; Guedea, F.

    2011-01-01

    The authors report an analysis of results obtained on 304 patients who have been treated by curie-therapy for a non-metastatic choroidal melanoma. They address the treatment (exclusive curie-therapy, local relapse, and adjuvant surgery), the treatment type (iodine-125 plate, ruthenium plate, and dose level), the survival, metastatic evolutions, toxicity occurrence, and vision quality. In most of the cases, curie-therapy results in ocular conservation and in an acceptable vision. Short communication

  3. Experimental evaluation of neutron dose in radiotherapy patients: Which dose?

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Expósito, M., E-mail: mariateresa.romero@uab.cat; Domingo, C.; Ortega-Gelabert, O.; Gallego, S. [Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193 (Spain); Sánchez-Doblado, F. [Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009 (Spain); Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41009 (Spain)

    2016-01-15

    Purpose: The evaluation of peripheral dose has become a relevant issue recently, in particular, the contribution of secondary neutrons. However, after the revision of the Recommendations of the International Commission on Radiological Protection, there has been a lack of experimental procedure for its evaluation. Specifically, the problem comes from the replacement of organ dose equivalent by the organ-equivalent dose, being the latter “immeasurable” by definition. Therefore, dose equivalent has to be still used although it needs the calculation of the radiation quality factor Q, which depends on the unrestricted linear energy transfer, for the specific neutron irradiation conditions. On the other hand, equivalent dose is computed through the radiation weighting factor w{sub R}, which can be easily calculated using the continuous function provided by the recommendations. The aim of the paper is to compare the dose equivalent evaluated following the definition, that is, using Q, with the values obtained by replacing the quality factor with w{sub R}. Methods: Dose equivalents were estimated in selected points inside a phantom. Two types of medical environments were chosen for the irradiations: a photon- and a proton-therapy facility. For the estimation of dose equivalent, a poly-allyl-diglicol-carbonate-based neutron dosimeter was used for neutron fluence measurements and, additionally, Monte Carlo simulations were performed to obtain the energy spectrum of the fluence in each point. Results: The main contribution to dose equivalent comes from neutrons with energy higher than 0.1 MeV, even when they represent the smallest contribution in fluence. For this range of energy, the radiation quality factor and the radiation weighting factor are approximately equal. Then, dose equivalents evaluated using both factors are compatible, with differences below 12%. Conclusions: Quality factor can be replaced by the radiation weighting factor in the evaluation of dose

  4. Marie Curie: the Curie Institute in Senegal to Nuclear Physics

    Science.gov (United States)

    Gueye, Paul

    Sub-Saharan Africa is not a place where one will look first when radioactivity or nuclear physics is mentioned. Conducting forefront research at the international stage at US national facilities such as the Thomas Jefferson National Accelerator Facility in Virginia or the National Superconducting Cyclotron Facility/Facility for Rare Isotope Beams in Michigan does not point to Historically Black Colleges either. The two are actually intrinsically connected as my personal journey from my early exposure to radiation at the Curie Institute at the LeDantec Hospital in Senegal lead me to Hampton University. The former, through one of my uncles, catapulted me into a nuclear physics PhD while the latter houses the only nuclear physics program at an HBCU to date that has established itself as one of the premier programs in the nation. This talk will review the impact of Marie Curie in my life as a nuclear physicist.

  5. A comparison of software programs to determine curie content

    International Nuclear Information System (INIS)

    Hansen, C.J.; Miller C.C.

    1995-01-01

    Commercial nuclear power plants have used various methods to determine the curie content of radwaste packages to comply with shipping and disposal regulations. Several computer software packages are available which can determine the curie content of a package based on the geometry of the package and the dose rate of the package provided a given source spectrum. This paper will compare three of the more commonly used software packages. A brief review of the selection and use of software programs at Diablo Canyon Power Plant for radwaste and radioactive material shipments will be provided. These software packages are the PAKRAD program by Bechtel (which utilizes EPRI DOSCON data), RAMSHP by WMG and MICROSHIELD by Grove Engineering. A comparison of the software packages in the calculation of curie content for a box of dry active waste and a cartridge filter will be presented. A summary of program limitations will also be provided

  6. Pozytywizm, racjonalizm i... romantyzm Marii Skłodowskiej-Curie

    Directory of Open Access Journals (Sweden)

    Barbara Petelenz

    2015-12-01

    Full Text Available The International Year of Chemistry (2011, intertwined with commemoration of the Nobel Prize in Chemistry awarded in 1911 to Marie Skłodowska-Curie, made me to ask about the philosophical background of this outstanding woman. The first factor which I could see was the positivism, launched by August Comte in France and developed a few decades later by his Polish followers. Another factor which seemed to me important was the interplay between the emotional (romantic and intellectual (positivistic attitudes among the Poles in the 19th century. In her research, Marie Skłodowska-Curie used the positivistic, rationalistic method. This has led her (jointly with her husband Pierre Curie to elucidation of the radiation phenomena discovered by Henri Becquerel in 1896. The research initiated by the Curies (rewarded by the half of the Nobel Prize in Physics 1903 caused a subversion of the 19th century’s views on the structure of Matter. The way to such spectacular results must have been paved not only by the positivistic intellectual discipline but also by a dose of romantic enchantment. In the applicative terms, Marie Skłodowska-Curie became a pioneer of the evidence-based medicine. In moral terms, she represented a rare example of the practical altruism, inspired indirectly by Christianity, and directly by the Comte’s “religion of Humanity”.

  7. A dose error evaluation study for 4D dose calculations

    Science.gov (United States)

    Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

    2014-10-01

    Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex

  8. Marie Curie: Physicist and Woman

    Science.gov (United States)

    Howes, Ruth

    Marie Sklodowska was born in Warsaw on November 7, 1867. Girls were not allowed to attend college in Poland, so Marie found a well-paying post as a governess in rural village which she held for three years while helping her older sister complete medical school in Paris. Then Marie moved to Paris and graduated first in her class at the Sorbonne with a master's degree in physics in 1893. In 1895, she married the talented young physicist, Pierre Curie. Marie decided to investigate the radioactive components of the mineral pitchblende for her dissertation. The work involved chemical analysis of a ton of material in an unheated shed. Pierre joined her and at the end of 1898, the Curies announced the discovery of radium and polonium. Through 1899, Marie labored to measure the atomic weight of radium. In 1903, Marie earned her doctorate, the first for a woman in France, and the Curies split the Nobel Prize in Physics with Henri Becquerel. They became widely known, besieged by the press and frequently invited to make presentations and be awarded honors. They hated fame and both suffered bad health. In April, 1906, Pierre Curie was struck by a wagon and killed instantly. Marie was left as a single mother with two young daughters. Fortunately, the Sorbonne hired her to fill Pierre's position. In 1911, she was rejected for membership in the French Academy of Science because she was a woman. Also in 1911, she was accused of having an affair with a married French physicist Paul Langevin. The resulting scandal hit the press and brought angry mobs to her home. In the middle of this hullaballoo, she was informed that she had won a second Nobel Prize, this time in Chemistry. When World War I broke out, Marie mounted x-ray units on cars and became a heroine. She visited the United States in 1921 where President Harding presented her with a gram of radium. She continued her scientific studies in spite of declining health until her death in 1934. Professor Emerita.

  9. [Evaluation of Organ Dose Estimation from Indices of CT Dose Using Dose Index Registry].

    Science.gov (United States)

    Iriuchijima, Akiko; Fukushima, Yasuhiro; Ogura, Akio

    Direct measurement of each patient organ dose from computed tomography (CT) is not possible. Most methods to estimate patient organ dose is using Monte Carlo simulation with dedicated software. However, dedicated software is too expensive for small scale hospitals. Not every hospital can estimate organ dose with dedicated software. The purpose of this study was to evaluate the simple method of organ dose estimation using some common indices of CT dose. The Monte Carlo simulation software Radimetrics (Bayer) was used for calculating organ dose and analysis relationship between indices of CT dose and organ dose. Multidetector CT scanners were compared with those from two manufactures (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). Using stored patient data from Radimetrics, the relationships between indices of CT dose and organ dose were indicated as each formula for estimating organ dose. The accuracy of estimation method of organ dose was compared with the results of Monte Carlo simulation using the Bland-Altman plots. In the results, SSDE was the feasible index for estimation organ dose in almost organs because it reflected each patient size. The differences of organ dose between estimation and simulation were within 23%. In conclusion, our estimation method of organ dose using indices of CT dose is convenient for clinical with accuracy.

  10. Magnons at the Curie temperature

    International Nuclear Information System (INIS)

    Poling, D.A.

    1982-01-01

    Random phase approximations (RPA) have very successfully treated spin wave excitations in Heisenberg ferromagnets at low temperatures. The role played by these magnons at the order-disorder transition, however, has been a topic which has eluded RPA theories to date. In light of recent data 1 , the idea of magnons at the Curie temperature and above has become more difficult to refute. This adds incentive to attempt to model interacting magnons at the Curie temperature. This work examines some attempts to formulate higher random phase approximations and discusses why they fail as they approach the transition temperature. A new interpretation of some work by Parmenter and author 2 is presented. The nature of the approximations made in that work is discussed, and an attempt is made to eliminate incorrect contributions from the energetically disfavored paramagnetic state to the correct magnon renormalization. A solution is presented which has the proper low temperature behavior as demonstrated by Dyson 3 restored and the reentrant behavior eliminated. An examination of how close this model comes to behaving correctly is performed, and a comparison is made to some recent work by Parmenter 4

  11. Superficial dose evaluation of four dose calculation algorithms

    Science.gov (United States)

    Cao, Ying; Yang, Xiaoyu; Yang, Zhen; Qiu, Xiaoping; Lv, Zhiping; Lei, Mingjun; Liu, Gui; Zhang, Zijian; Hu, Yongmei

    2017-08-01

    Accurate superficial dose calculation is of major importance because of the skin toxicity in radiotherapy, especially within the initial 2 mm depth being considered more clinically relevant. The aim of this study is to evaluate superficial dose calculation accuracy of four commonly used algorithms in commercially available treatment planning systems (TPS) by Monte Carlo (MC) simulation and film measurements. The superficial dose in a simple geometrical phantom with size of 30 cm×30 cm×30 cm was calculated by PBC (Pencil Beam Convolution), AAA (Analytical Anisotropic Algorithm), AXB (Acuros XB) in Eclipse system and CCC (Collapsed Cone Convolution) in Raystation system under the conditions of source to surface distance (SSD) of 100 cm and field size (FS) of 10×10 cm2. EGSnrc (BEAMnrc/DOSXYZnrc) program was performed to simulate the central axis dose distribution of Varian Trilogy accelerator, combined with measurements of superficial dose distribution by an extrapolation method of multilayer radiochromic films, to estimate the dose calculation accuracy of four algorithms in the superficial region which was recommended in detail by the ICRU (International Commission on Radiation Units and Measurement) and the ICRP (International Commission on Radiological Protection). In superficial region, good agreement was achieved between MC simulation and film extrapolation method, with the mean differences less than 1%, 2% and 5% for 0°, 30° and 60°, respectively. The relative skin dose errors were 0.84%, 1.88% and 3.90%; the mean dose discrepancies (0°, 30° and 60°) between each of four algorithms and MC simulation were (2.41±1.55%, 3.11±2.40%, and 1.53±1.05%), (3.09±3.00%, 3.10±3.01%, and 3.77±3.59%), (3.16±1.50%, 8.70±2.84%, and 18.20±4.10%) and (14.45±4.66%, 10.74±4.54%, and 3.34±3.26%) for AXB, CCC, AAA and PBC respectively. Monte Carlo simulation verified the feasibility of the superficial dose measurements by multilayer Gafchromic films. And the rank

  12. Intracavitary radiation treatment planning and dose evaluation

    International Nuclear Information System (INIS)

    Anderson, L.L.; Masterson, M.E.; Nori, D.

    1987-01-01

    Intracavitary radiation therapy with encapsulated radionuclide sources has generally involved, since the advent of afterloading techniques, inserting the sources in tubing previously positioned within a body cavity near the region to be treated. Because of the constraints on source locations relative to the target region, the functions of treatment planning and dose evaluation, usually clearly separable in interstitial brachytherapy, tend to merge in intracavitary therapy. Dose evaluation is typically performed for multiple source-strength configurations in the process of planning and thus may be regarded as complete when a particular configuration has been selected. The input data for each dose evaluation, of course, must include reliable dose distribution information for the source-applicator combinations used. Ultimately, the goal is to discover the source-strength configuration that results in the closest possible approach to the dose distribution desired

  13. Manual of dose evaluation from atmospheric releases

    Energy Technology Data Exchange (ETDEWEB)

    Shirvaikar, V V; Abrol, V [Health Physics Division, Bhabha Atomic Research Centre, Bombay (India)

    1978-07-01

    The problem of dose evaluation from atmospheric releases is reduced to simple arithmetic by giving tables of concentrations and time integrated concentrations for instantaneous plumes and long time (1 year), sector averaged plumes for distances upto 10 km, effective release heights of upto 200 m and the six Pasquill stability classes. Correction factors for decay, depletion due to deposition and rainout are also given. Inhalation doses, immersion doses and contamination levels can be obtained from these by using multiplicative factors tabulated for various isotopes of significance. Tables of external gamma doses from plume are given separately for various gamma energies. Tables are also given to evaluate external beta and gamma dose rates from contaminated surfaces. The manual also discusses the basic diffusion model relevant to the problem. (author)

  14. Dose evaluation of narrow-beam

    International Nuclear Information System (INIS)

    Goto, Shinichi

    1999-01-01

    Reliability of the dose from the narrow photon beam becomes more important since the single high-dose rate radiosurgery becoming popular. The dose evaluation for the optimal dose is difficult due to absence of lateral electronic equilibrium. Data necessary for treatment regimen are TMR (tissue maximum ratio), OCR (off center ratio) and S c,p (total scatter factor). The narrow-beam was 10 MV X-ray from Varian Clinac 2100C equipped with cylindrical Fischer collimator CBI system. Detection was performed by Kodak XV-2 film, a PTW natural diamond detector M60003, Scanditronics silicon detector EDD-5 or Fujitec micro-chamber FDC-9.4C. Phantoms were the water equivalent one (PTW, RW3), water one (PTW, MP3 system) and Wellhofer WP600 system. Factors above were actually measured to reveal that in the dose evaluation of narrow photon beam, TMR should be measured by micro-chamber, OCR, by film, and S c,p , by the two. The use of diamond detector was recommended for more precise measurement and evaluation of the dose. The importance of water phantom in the radiosurgery system was also shown. (K.H.)

  15. Evaluation of radiation doses from radioactive drugs

    International Nuclear Information System (INIS)

    Halperin, J.A.; Grove, G.R.

    1977-01-01

    Radioactive new drugs are regulated by the Food and Drug Administration (FDA) in the United States. Before a new drug can be marketed it must have an approved New Drug Application (NDA). Clinical investigations of a radioactive new drug are carried out under a Notice of Claimed Investigational Exemption for a New Drug (IND), submitted to the FDA. In the review of the IND, radiation doses are projected on the basis of experimental data from animal models and from calculations based upon radiation characteristics, predicted biodistribution of the drug in humans, and activity to be administered. FDA physicians review anticipated doses and prevent clinical investigations in humans when the potential risk of the use of a radioactive substance outweighs the prospect of achieving beneficial results from the administration of the drug. In the evaluation of an NDA, FDA staff attempt to assure that the intended diagnostic or therapeutic effect is achievable with the lowest practicable radiation dose. Radiation doses from radioactive new drugs are evaluated by physicians within the FDA. Important radioactive new drugs are also evaluated by the Radiopharmaceuticals Advisory Committee. FDA also supports the Center for Internal Radiation Dosimetry at Oak Ridge, to provide information regarding in vivo distribution and dosimetry to critical organs and the whole body from radioactive new drugs. The process for evaluation of radiation doses from radioactive new drugs for protection against use of unnecessary radiation exposure by patients in nuclear medicine procedures, a

  16. Some aspects of dose evaluation, 3

    International Nuclear Information System (INIS)

    Yoshida, Yoshikazu

    1979-01-01

    This paper describes methods of calculating the radioiodine releases and resultant doses in the ''Guide for calculation of doses to man from routine releases of effluents from light-water-cooled nuclear power plants for evaluating compliance with dose objectives around a site of LWRs'' by the Japan Nuclear Safety Commission. Examples of dose calculation in the design stage of plants and releases of radioiodine from operating plants are also given. The thyroid dose objective from radioiodine in reactor effluents was determined to be 15 mrem per year by the AEC of Japan in 1975. In the guide, models and parameters are given as most realistic on the basis of current knowledge and experience; in cases involving unknown factors these are on conservative side. Calculations of annual average releases of gaseous and liquid effluents are made using the models and parameters established through operational experiences of the LWR plants. Annual thyroid doses are calculated from inhalation and ingestion of leafy vegetable and cow's milk for gaseous effluents and ingestion of marine food for liquid effluents. In calculation of the thyroid dose, fw = 0.2 is used instead of = 0.3 in ICRP publ. 2 for ingestion of foods excluding seaweed and the specific activity method for ingestion of foods including seaweed. It is because Japanese take foods with much stable iodine. Calculated annual releases of 131 I in gaseous effluents of typical BWR (1100 MWe) and PWR (800 MWe) are about 2 Ci and 0.7 Ci per year per plant and the annual thyroid doses are about 4 mrem and 9 mrem per year, respectively. Actually, however, releases of 131 I in gaseous effluents from the operating LWR plants are about less than one tenth of the above figures. (author)

  17. [Evaluation of patient doses in interventional radiology].

    Science.gov (United States)

    Ropolo, R; Rampado, O; Isoardi, P; Gandini, G; Rabbia, C; Righi, D

    2001-01-01

    To verify the suitability of indicative quantities to evaluate the risk related to patient exposure, in abdominal and vascular interventional radiology, by the study of correlations between dosimetric quantities and other indicators. We performed in vivo measurements of entrance skin dose (ESD) and dose area product (DAP) during 48 procedures to evaluate the correlation among dosimetric quantities, and an estimation of spatial distribution of exposure and effective dose (E). To measure DAP we used a transmission ionization chamber and to evaluate ESD and its spatial distribution we used radiographic film packed in a single envelope and placed near the patient's skin. E was estimated by a calculation software using data from film digitalisation. From the data derived for measurements in 27 interventional procedures on 48 patients we obtained a DAP to E conversion factor of 0.15 mSv / Gy cm2, with an excellent correlation (r=.99). We also found a good correlation between DAP and exposure parameters such as fluoroscopy time and number of images. The greatest effective dose was evaluated for a multiple procedure in the hepatic region, with a DAP value of 425 Gy cm2. The greatest ESD was about 550 mGy. For groups of patients undergoing similar interventional procedures the correlation between ESD and DAP had conversion factors from 6 to 12 mGy Gy-1 cm-2. The evaluation of ESD and E by slow films represents a valid method for patient dosimetry in interventional radiology. The good correlation between DAP and fluoroscopy time and number of images confirm the suitability of these indicators as basic dosimetric information. All the ESD values found are lower than threshold doses for deterministic effects.

  18. Frederic Joliot-Curie, a tormented scientist

    International Nuclear Information System (INIS)

    Pinault, M.

    2000-01-01

    This article is a short biography of the French scientist Frederic Joliot-Curie. His fight for a peaceful use of atomic energy, his responsibilities as nuclear physicist and as the first director of the French atomic commission (CEA) have led him to face contradictions very difficult to manage. All along his career as a scientist and as a high ranked civil servant, F.Joliot-Curie tried to find an ethical way for scientists in modern societies. (A.C.)

  19. Evaluation of lens dose in medulloblastoma radiotherapy

    International Nuclear Information System (INIS)

    Oliveira, F.L.; Vilela, E.C.; Sousa, S.A; Lima, F.F. de

    2007-01-01

    The improvement of the applied radiotherapy techniques in the cranial-spinal therapy, which is used in the cases of medulloblastoma, aims the reduction of the risks of future damages in enclosed critical agencies in the irradiation fields. This work aims to evaluate the lens doses due two common techniques used in medulloblastoma radiotherapy. For this, thermoluminescent dosimeters, previously calibrated, were located in an anthropomorphic phantom (ALDERSON - RANDON Laboratory), in the tumor and lens positions. The employed techniques were as following: (1) angled fields technique and (2) half-beam block technique. The phantom was irradiated five times in each technique with two lateral opposed fields in the brain with a total prescribed dose of 1.5 Gy, followed of two posterior spinal fields with the same prescribed dose, using a 6MV accelerator. The results showed that the doses in the first technique were 0.10 +- 0,04 Gy and, in second one, 0.09 +- 0,02 Gy. It was observed that, independent of the employed technique, the lens doses practically are the same. (author)

  20. Evaluation of doses in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Canevaro, Lucia Viviana

    1995-04-01

    This work aims at the development of a methodology to measure radiation doses to patients and professionals (radiologists) in fluoroscopic gastrointestinal tract examinations. Also, it aims at the assessment of the performance of this type of medical x-ray equipment, from the radiation protection point of view at the Department of Radiology of the Hospital Universitario Clementino Fraga Filho (Universidade Federal de Rio de Janeiro). This work was developed in order to identify the actual status and to set base lines as a reference for a quality control program. The calibration procedures of thermoluminescent dosimeters for radiodiagnosis quality beams are discussed and described here as well as its application in dose measurements, for patients and radiologists. The performance of two types of x-ray equipment (fluorescent screen and image intensifier) usually used to perform this examinations was evaluated through appropriate tests. Radiation protection features are also considered. Dose to radiologists at unprotected regions and to patients at several sample points were measured. A comparison of the measured doses given by both types of equipment was made. After further analysis, the necessity to look for methods that reduce unnecessary doses became evident. The high values obtained in some procedures using fluorescent screen make the use of this type of equipment unacceptable. With these results, we consider that Health Care authorities have the responsibility of replacing all fluorescent screen equipment and of establishing standards, and raising awareness the responsible staff. (author)

  1. DOZIM - evaluation dose code for nuclear accident

    International Nuclear Information System (INIS)

    Oprea, I.; Musat, D.; Ionita, I.

    2008-01-01

    During a nuclear accident an environmentally significant fission products release can happen. In that case it is not possible to determine precisely the air fission products concentration and, consequently, the estimated doses will be affected by certain errors. The stringent requirement to cope with a nuclear accident, even minor, imposes creation of a computation method for emergency dosimetric evaluations needed to compare the measurement data to certain reference levels, previously established. These comparisons will allow a qualified option regarding the necessary actions to diminish the accident effects. DOZIM code estimates the soil contamination and the irradiation doses produced either by radioactive plume or by soil contamination. Irradiations either on whole body or on certain organs, as well as internal contamination doses produced by isotope inhalation during radioactive plume crossing are taken into account. The calculus does not consider neither the internal contamination produced by contaminated food consumption, or that produced by radioactive deposits resuspension. The code is recommended for dose computation on the wind direction, at distances from 10 2 to 2 x 10 4 m. The DOZIM code was utilized for three different cases: - In air TRIGA-SSR fuel bundle destruction with different input data for fission products fractions released into the environment; - Chernobyl-like accident doses estimation; - Intervention areas determination for a hypothetical severe accident at Cernavoda Nuclear Power Plant. For the first case input data and results (for a 60 m emission height without iodine retention on active coal filters) are presented. To summarize, the DOZIM code conception allows the dose estimation for any nuclear accident. Fission products inventory, released fractions, emission conditions, atmospherical and geographical parameters are the input data. Dosimetric factors are included in the program. The program is in FORTRAN IV language and was run on

  2. Dose evaluation from multiple detector outputs using convex optimisation

    International Nuclear Information System (INIS)

    Hashimoto, M.; Iimoto, T.; Kosako, T.

    2011-01-01

    A dose evaluation using multiple radiation detectors can be improved by the convex optimisation method. It enables flexible dose evaluation corresponding to the actual radiation energy spectrum. An application to the neutron ambient dose equivalent evaluation is investigated using a mixed-gas proportional counter. The convex derives the certain neutron ambient dose with certain width corresponding to the true neutron energy spectrum. The range of the evaluated dose is comparable to the error of conventional neutron dose measurement equipments. An application to the neutron individual dose equivalent measurement is also investigated. Convexes of particular dosemeter combinations evaluate the individual dose equivalent better than the dose evaluation of a single dosemeter. The combinations of dosemeters with high orthogonality of their response characteristics tend to provide a good suitability for dose evaluation. (authors)

  3. LUDEP: A Lung Dose Evaluation Program

    International Nuclear Information System (INIS)

    Birchall, A.; Bailey, M.R.; James, A.C.

    1990-06-01

    A Task Group of the ICRP is currently reviewing its dosimetric model for the respiratory tract with the aim of producing a more comprehensive and realistic model which can be used both for dosimetry and bioassay purposes. This in turn requires deposition, clearance, and dosimetry to be treated in a more detailed manner in than in the current model. In order to examine the practical application and radiological implications of the proposed model, a microcomputer program has been developed in a modular form so that changes can be easily included as the model develops. LUDEP (Lung Dose Evaluation Program) is a user-friendly menu-driven program which can be operated on any IBM-compatible PC. It enables the user to calculate (a) doses to each region of the respiratory tract and all other body organs, and (b) excretion rates and retention curves for bioassay purposes. 11 refs., 4 figs., 6 tabs

  4. Marie and Pierre Curie. Life in extremes

    International Nuclear Information System (INIS)

    Roethlein, Brigitte

    2008-01-01

    In Paris in 1894, two young physicists fall in love: Marie Sklodowska and Pierre Curie. They get married and make great contributions to science, research radioactivity and discover new chemical elements. The marriage of Marie and Pierre Curie is quite modern: They work together as equals, share their thoughts and pursue their plans together as partners. They share an absolute interest in science, a love of nature, and a sceptic attitude towards the sophisticated society of the Belle Epoque. They are together 24 hours a day with hardly ever any disagreement. Whenever one of them is ill - which is quite often because of the high level of radioactivity in their laboratory -, the other will nurse him or her. After only twelve years of mutual love, Pierre Curie dies. Marie raises their two daughters on her own and continues her research. In 1911, she will be the first scientist that ever gets a second Nobel Prize. (orig.) [de

  5. Marie Curie: In the laboratory and on the battlefield

    International Nuclear Information System (INIS)

    Badash, Lawrence

    2003-01-01

    This year is the centennial of the Nobel Prize in Physics shared by Henri Becquerel and the Curies for their pioneering work on radioactivity. But Marie Curie's contribution to the medical use of x rays is not widely known

  6. Dose evaluation in diagnostic for computerized tomography

    International Nuclear Information System (INIS)

    Flores, W.; Borges, J.C.; Mota, H.

    1998-01-01

    The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

  7. Marie Curie - science was her life

    International Nuclear Information System (INIS)

    Wolschendorf, K.

    1998-01-01

    In this paper a short survey of the life and the work of Marie Curie is presented. She was born in 1867 in Warsaw/Poland and went to Paris in 1891 to study physics, mathematics, and chemistry. In 1895 the married the physicist Pierre Curie, and together they began research work on radioactivity. For her doctorate she investigated various radiating substances and discovered the radioactive element Radium in 1898. She was awarded the Nobel Prize in Physics in 1903, and later on the Nobel Prize in Chemistry in 1911 for performing pioneering studies with radium and contributing profoundly to the understanding of radioactivity. In 1934 she died in a health resort due to leukemia. (orig.) [de

  8. Marie and Pierre Curie: joined in science

    International Nuclear Information System (INIS)

    Lehembre, B.

    1999-01-01

    This book relates the life and works of the most famous married couple of scientists. Their works have completely overturned the science of the 20. century and their discovery of radium was rewarded by the Nobel price in 1903. This marriage both in science and life ended three years later because of a banal accident: Pierre Curie is fatally knocked down by a horse carriage in Paris. (J.S.)

  9. Evaluation of effective dose and excess lifetime cancer risk from ...

    African Journals Online (AJOL)

    Evaluation of effective dose and excess lifetime cancer risk from indoor and outdoor gamma dose rate of university of Port Harcourt Teaching Hospital, Rivers State. ... Therefore, the management of University of Port Harcourt teaching hospital ...

  10. Fetal dose evaluation during breast cancer radiotherapy

    International Nuclear Information System (INIS)

    Antypas, Christos; Sandilos, Panagiotis; Kouvaris, John; Balafouta, Ersi; Karinou, Eleftheria; Kollaros, Nikos; Vlahos, Lambros

    1998-01-01

    Purpose: The aim of the work was to estimate the radiation dose delivered to the fetus in a pregnant patient irradiated for breast cancer. Methods and Materials: A 45-year woman was treated for left breast cancer using a 6 MV photon beam with two isocentric opposing tangential unwedged fields. Daily dose was 2.3 Gy at 95% isodose line given by two fields/day, 5 days/week. A total dose of 46 Gy was given in 20 fractions over a 4-week period. Pregnancy confirmed during the second therapeutic week. Treatment lasted between the second and sixth gestation week. Radiation dose to fetus was estimated from in vivo and phantom measurements using thermoluminescence dosimeters and an ionization chamber. In vivo measurements were performed by inserting either a catheter with TL dosimeters or ionization chamber into the patient's rectum. Phantom measurements were performed by simulating the treatment conditions on an anthropomorphic phantom. Results: TLD measurements (in vivo and phantom) revealed fetal dose to be 0.085% of the tumor dose, corresponding to a cumulative fetal dose of 3.9 cGy for the entire treatment of 46 Gy. Chamber measurements (in vivo and phantom) revealed a fetal dose less than the TLD result: 0.079 and 0.083% of the tumor dose corresponding to cumulative fetal dose of 3.6 cGy and 3.8 cGy for in vivo and phantom measurement, respectively. Conclusions: It was concluded that the cumulative dose delivered to the unshielded fetus was 3.9 cGy for a 46 Gy total tumor dose. The estimated fetal dose is low compared to the total tumor dose given due to the early stage of pregnancy, the large distance between fundus-radiation field, and the fact that no wedges and/or lead blocks were used. No deterministic biological effects of radiation on the live-born embryo are expected. The lifetime risk for radiation-induced fatal cancer is higher than the normal incidence, but is considered as inconsequential

  11. Dose evaluation and protection of cosmic radiation

    International Nuclear Information System (INIS)

    Iwai, Satoshi; Takagi, Toshiharu

    2004-01-01

    This paper explained the effects of cosmic radiation on aircraft crews and astronauts, as well as related regulations. International Commission on Radiological Protection (ICRP) recommends the practice of radiation exposure management for the handling/storage of radon and materials containing natural radioactive substances, as well as for boarding jet aircraft and space flight. Common aircraft crew members are not subject to radiation exposure management in the USA and Japan. In the EU, the limit value is 6 mSv per year, and for the crew group exceeding this value, it is recommended to keep records containing appropriate medical examination results. Pregnant female crewmembers are required to keep an abdominal surface dose within 1 mSv. For astronauts, ICRP is in the stage of thinking about exposure management. In the USA, National Council on Radiation Protection and Measurement has set dose limits for 30 days, 1 year, and lifetime, and recommends lifetime effective dose limits against carcinogenic risk for each gender and age group. This is the setting of the dose limits so that the risk of carcinogenesis, to which space radiation exposure is considered to contribute, will reach 3%. For cosmic radiation environments at spacecraft inside and aircraft altitude, radiation doses can be calculated for astronauts and crew members, using the calculation methods for effective dose and dose equivalent for tissue. (A.O.)

  12. Two wives in science service: Marie Curie and Irene Joliot-Curie

    International Nuclear Information System (INIS)

    Bordry, M.

    1996-01-01

    This paper relates the life and the scientific works of Marie Curie and of her daughter Irene Joliot-Curie in their historical context. Several details are given about their laboratory works, their relations with students, the creation of the Radium Institute and the role they played during the two world wars. The progress of their works towards their main scientific discoveries (polonium, radium, artificial radioactivity, transuranium compounds etc..) is illustrated with some extracts of their personal correspondence with relatives. The paper evokes also the Nobel prices received by Pierre and Marie Curie and by Irene and Frederic Joliot and the creation of the CEA by Frederic Joliot in 1946. (J.S.). 6 photos

  13. Prescribing and evaluating target dose in dose-painting treatment plans

    DEFF Research Database (Denmark)

    Håkansson, Katrin; Specht, Lena; Aznar, Marianne C

    2014-01-01

    BACKGROUND: Assessment of target dose conformity in multi-dose-level treatment plans is challenging due to inevitable over/underdosage at the border zone between dose levels. Here, we evaluate different target dose prescription planning aims and approaches to evaluate the relative merit of such p......-painting and multi-dose-level plans. The tool can be useful for quality assurance of multi-center trials, and for visualizing the development of treatment planning in routine clinical practice....... of such plans. A quality volume histogram (QVH) tool for history-based evaluation is proposed. MATERIAL AND METHODS: Twenty head and neck cancer dose-painting plans with five prescription levels were evaluated, as well as clinically delivered simultaneous integrated boost (SIB) plans from 2010 and 2012. The QVH...

  14. Marie and Pierre Curie. Life in extremes; Marie and Pierre Curie. Leben in Extremen

    Energy Technology Data Exchange (ETDEWEB)

    Roethlein, Brigitte

    2008-07-01

    In Paris in 1894, two young physicists fall in love: Marie Sklodowska and Pierre Curie. They get married and make great contributions to science, research radioactivity and discover new chemical elements. The marriage of Marie and Pierre Curie is quite modern: They work together as equals, share their thoughts and pursue their plans together as partners. They share an absolute interest in science, a love of nature, and a sceptic attitude towards the sophisticated society of the Belle Epoque. They are together 24 hours a day with hardly ever any disagreement. Whenever one of them is ill - which is quite often because of the high level of radioactivity in their laboratory -, the other will nurse him or her. After only twelve years of mutual love, Pierre Curie dies. Marie raises their two daughters on her own and continues her research. In 1911, she will be the first scientist that ever gets a second Nobel Prize. (orig.) [German] Im Paris des Jahres 1894 verlieben sich zwei junge Physiker: Marie Sklodowska und Pierre Curie. Sie heiraten und leisten gemeinsam Grosses fuer die Wissenschaft, erforschen die Radioaktivitaet und entdecken neue chemische Elemente. Zusammen erhalten sie den Nobelpreis. Marie und Pierre Curie fuehren eine Ehe, die ihrer Zeit weit voraus ist: Sie arbeiten gleichberechtigt miteinander, teilen ihre Gedanken und verfolgen ihre Plaene gemeinsam. Beiden eigen ist die absolute wissenschaftliche Neugier, die Liebe zur Natur und die Skepsis gegenueber der mondaenen Gesellschaft der Belle Epoque. Fast jeden Tag sind sie rund um die Uhr zusammen, dabei gibt es selten Spannungen. Wenn einer von beiden gesundheitliche Probleme hat - und das haben sie wegen der radioaktiven Belastung im Labor oft - ist der andere fuer ihn da und pflegt ihn. Nach nur zwoelf gemeinsamen Jahren der Liebe und Arbeit stirbt Pierre Curie. Marie zieht ihre beiden Toechter alleine gross und fuehrt die Forschungen weiter. 1911 erhaelt sie als erster Mensch zum zweiten Mal den

  15. Vancomycin Utilization Evaluation: Are We Dosing Appropriately?

    Directory of Open Access Journals (Sweden)

    Ladan Ayazkhoo

    2015-10-01

    Full Text Available Background: Inappropriate use of vancomycin not only increase health care costs but also contribute to the emergence of resistant organisms. Higher trough serum vancomycin concentrations (>10mg/L has been recommended for avoidance of development of resistance. We aim to compare the administered dose with recommended doses based on guideline-recommended weight-based dosing.Methods: In a cross sectional study, all patients who received vancomycin between July and October 2013, in infectious disease, internal medicine wards and emergency department of a teaching hospital in Tehran, Iran were entered to the study. Indication of vancomycin and necessary data for dose calculation including height and serum creatinine were recorded. Prescribed doses were compared with recommended doses in guidelines and calculated Glomerular filtration rate (GFR for each patient.Results: One hundred and four patients (45 females and 59 males recruited in the study. Our results indicated that, from all administered doses of vancomycin, 64.4% and 88.8% differs significantly (more than 20% based on American Pharmacist Association (AphA vancomycin monograph and guideline-recommended, weight-based vancomycin dosing (for adults, respectively.Conclusion: Underdosing of vancomycin is a major risk factor for developing resistance of gram positive organisms to this glycopeptide. Our results showed that more than half of patients receiving vancomycin are in the risk of low drug levels based on guidelines. So, having a comprehensive plan for the proper use of this drug especially designing effective internal guidelines can prevent emergence of resistance to vancomycin in future.

  16. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Alzimami, K.; Habeeballa, B.; Osman, H.; Abdelaziz, I.; Sassi, S.A.; Sam, A.K.

    2015-01-01

    This study intends to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (DHS) and (ii) Dynamic Cannula Screw (DCS) and to evaluate entrance surface Air kerma (ESAK) dose and organ doses and effective doses. Calibrated Thermoluminescence dosimeters (TLD-GR200A) were used. The mean patients’ doses were 0.46 mGy and 0.07 mGy for DHS and DCS procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean organ and effective dose for patients and staff were higher in DHS compared to DCS. Orthopedic surgeons were exposed to unnecessary radiation doses due to the lack of protection measures. The radiation dose per hip procedure is within the safety limit and less than the previous studies

  17. Correct statistical evaluation for total dose in rural settlement

    International Nuclear Information System (INIS)

    Vlasova, N.G.; Skryabin, A.M.

    2001-01-01

    Statistical evaluation of dose reduced to the determination of an average value and its error. If an average value of a total dose in general can be determined by simple summarizing of the averages of its external and internal components, the evaluation of an error can be received only from its distribution. Herewith, considering that both components of the dose are interdependent, to summarize their distributions, as a last ones of a random independent variables, is incorrect. It follows that an evaluation of the parameters of the total dose distribution, including an error, in general, cannot be received empirically, particularly, at the lack or absence of the data on one of the components of the last one, that constantly is happens in practice. If the evaluation of an average for total dose was defined somehow, as the best, as an average of a distribution of the values of individual total doses, as summarizing the individual external and internal doses by the random type, that an error of evaluation had not been produced. The methodical approach to evaluation of the total dose distribution at the lack of dosimetric information was designed. The essence of it is original way of an interpolation of an external dose distribution, using data on an internal dose

  18. In honour of Marie Sklodowska-Curie

    International Nuclear Information System (INIS)

    Karlik, Berta

    1967-01-01

    This year marks the hundredth anniversary of the birth in Poland of Marie Sklodowska-Curie, originator of the word 'radioactivity', whose early research in the subject has had far-reaching consequences for the nuclear sciences. The Government of Poland's arrangements for marking the occasion include an international symposium, restoration of her house in Warsaw, publications and films, and the Agency is happy to collaborate. This article, from a distinguished Austrian scientist, indicates how her work was carried out in an atmosphere of co-operation between scientists of many nations

  19. Symmetry, from Euclid to Pierre Curie

    International Nuclear Information System (INIS)

    Sivardiere, J.

    1997-01-01

    A historical review of the principles of symmetry is presented, starting with Egyptian pavements and Euclid regular polyhedrons, 2 and 3 dimensional paving studies with Kepler in the 17. century, modern crystallography with the constant angle law and the rational truncations law in the 18. century, the identification of the various crystal symmetries (19. century), the discovery of liquid crystals, the relations between the symmetry and the physical and optical properties of systems, molecules, etc.. Finally, P. Curie has determined the general principle of symmetry, linking symmetry and its effects

  20. Joliot-Curie nuclear physics school 1983

    International Nuclear Information System (INIS)

    The 1983 Joliot-Curie school was aimed at reviewing some outstanding aspects of current research in nuclear spectroscopy. The recent developments of high and very high spin states study are presented. The most important experimental methods and explaining concepts concerning the ground states and the first excited levels of nuclei far from beta stability are reviewed. Spin-isospin excitations are dealt with from a theoretical point of view and also for the most outstanding experimental results. At last, basic concepts and limits of the shell model nuclear description are outlined and illustrated [fr

  1. The life and legacy of Marie Curie.

    OpenAIRE

    Rockwell, Sara

    2003-01-01

    Marie Curie was a remarkable woman whose discoveries broke new ground in physics and chemistry and also opened the door for advances in engineering, biology, and medicine. She broke new ground for women in science: she was, for example, the first woman to receive a doctor of science degree in France, the first woman to win Nobel Prize, the first woman to lecture at the Sorbonne, the first person to win two Nobel Prizes, and the first Nobel Laureate whose child also won a Nobel Prize. Her life...

  2. Marie Curie's contribution to Medical Physics.

    Science.gov (United States)

    Jean-Claude, Rosenwald; Nüsslin, Fridtjof

    2013-09-01

    On occasion of its 50th anniversary, the International Organization for Medical Physics (IOMP) from now on is going to celebrate annually an International Day of Medical Physics for which the 7th November, the birthday of Marie Sklodowska Curie, a most exceptional character in science at all and a pioneer of medical physics, has been chosen. This article briefly outlines her outstanding personality, sketches her fundamental discovery of radioactivity and emphasizes the impact of her various achievements on the development of medical physics at large. © 2013 Published by Elsevier Ltd on behalf of Associazione Italiana di Fisica Medica.

  3. Evaluation of shipping doses and compositions for vitrified waste

    International Nuclear Information System (INIS)

    Shapiro, A.

    1996-01-01

    Shipments of radioactive materials must adhere to dose limits specified in the Code of Federal Regulations. This paper discusses methods for evaluating shipping doses of vitrified waste. A methodology was developed for evaluating the change in vitrification composition required to maintain shipping dose rates within limits. The point kernel codes QAD and Microshield were used to evaluate dose equivalent rates from specified waste forms and radioactivity measurements. The Origen code was utilized to provide the gamma-ray activity as a function of time from isotopic activity measurements. This gamma-ray activity served as source input for QAD. Microshield developed its own source from the given isotopic activities

  4. Measurement and evaluation of internal dose

    International Nuclear Information System (INIS)

    Lee, Tae Young; Chang, S. Y.; Lee, J. I.; Song, M. Y.

    2006-01-01

    This report describes the contents and results for implementation of internal radiation monitoring programme, measurement of uranium present in lung by lung counter and assessment of committed effective dose for radiation workers of the KNFC. The aim of radiation protection was achieved by implementing this activity

  5. Critical commentary on dose-rate evaluations

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Malenfant, R.E.; Plassmann, E.A.

    1984-01-01

    Survivors of Hiroshima and Nagasaki present a unique problem in dosimetry: the effects of radiation exposure may be inferred although the exposure itself is unknown. Experience with a replica of Little Boy demonstrates the difficulties of measuring dose rates, the problems of comparing measurements with calculations, and the inadequacy of the conventional standards that are used to calibrate dosimeters

  6. Evaluation of patient dose during computed tomography angiography

    International Nuclear Information System (INIS)

    Dafalla, Elamam Yagoob Taha

    2015-10-01

    Computed tomography (CT), is an x-ray procedure that generates high quality cross sectional images of the body, and by comparison to other radiological diagnosis, CT is responsible for higher doses to patients. The evaluation of patient dose from computed tomography for pulmonary examinations the CT is responsible for higher doses to patients. The radiation dose was measured in three hospitals in Khartoum State during March 2015-October 2015 using different CT modalities. The radiation dose was higher at Alzytouna hospital than Daralelaj hospital and Alatebaa hospital was lowest. In this study, the mean effective dose for first hospital was 23.83±3.93 mSv and the mean effective dose for second hospital was 8.94±1.64 mSv and the mean effective dose for third hospital was 2.96±0.79. (author)

  7. Small Column Ion Exchange Analysis for Removal of Cesium from SRS Low Curie Salt Solutions Using Crystalline Silicotitanate (CST) Resin

    International Nuclear Information System (INIS)

    ALEMAN, SEBASTIAN

    2004-01-01

    Savannah River Technology Center (SRTC) researchers modeled ion exchange removal of cesium from dissolved salt waste solutions. The results assist in evaluating proposed configurations for an ion exchange process to remove residual cesium from low curie waste streams. A process for polishing (i.e., removing small amounts) of cesium may prove useful should supernate draining fail to meet the Low Curie Salt (LCS) target limit of 0.1 Ci of Cs-137 per gallon of salt solution. Cesium loading isotherms and column breakthrough curves for Low Curie dissolved salt solutions were computed to provide performance predictions for various column designs

  8. Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

    International Nuclear Information System (INIS)

    Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

    2016-01-01

    In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

  9. Evaluations of gonad and fetal doses for diagnostic radiology.

    Science.gov (United States)

    Tung, C J; Tsai, H Y

    1999-07-01

    A national survey of patient doses for diagnostic radiology was planned in the Republic of China. We performed a pilot study for this survey to develop a protocol of the dose assessments. Entrance skin doses and organ (including ovary, testicle and uterus) doses were measured by thermoluminescent dosimeters and calculated by means of Monte Carlo simulations for several diagnostic procedures. We derived a formula and used the RadComp software for the computation of entrance skin doses. This formula involves several factors, such as kVp, mAs, the focus-to-skin-distance and aluminum filtration. RadComp software was applied to obtain free-air entrance exposures which were converted to entrance skin doses by considering the backscattering radiation from the body. Organ doses were measured using a RANDO phantom and calculated using a mathematical phantom for several diagnostic examinations. Genetically significant doses were calculated from ovary and testicle doses for the evaluation of hereditary effects. Embryo/fetal doses were determined from the uterine doses by considering the increase in uterus size with gestational age. We found that the patient doses studied in this work were all below the reference doses recommended by the National Radiological Protection Board of the U.K.

  10. An evaluation of high-dose jobs for ALARA improvement

    International Nuclear Information System (INIS)

    Mun, J. H.; Kim, H. S.

    1997-01-01

    It is well known that about 70 percent of occupational dose have incurred from maintenance jobs at outage period. To reduce occupational dose, first, the high-dose jobs at the outage period should be identified and evaluated. For this, the database program is used, which contains the ORE data of reference plants, Kori Units 3 and 4. As a result, it is found that the jobs related to steam generator are the highest dose jobs in terms of collective ORE dose. From the analysis of the job procedures of those jobs, the ALARA improvements are also derived

  11. Evaluation of the sterility of single-dose medications used in a multiple-dose fashion.

    Science.gov (United States)

    Martin, Elizabeth P; Mukherjee, Jean; Sharp, Claire R; Sinnott-Stutzman, Virginia B

    2017-11-01

    Bacterial proliferation was evaluated in single-dose medications used in a multi-dose fashion and when medications were intentionally inoculated with bacteria. Of 5 experimentally punctured medications, 1 of 75 vials (50% dextrose) became contaminated. When intentionally inoculated, hydroxyethyl starch and heparinized saline supported microbial growth. Based on these findings, it is recommended that hydroxyethyl starch and heparinized saline not be used in a multi-dose fashion.

  12. Curie temperature determination via thermogravimetric and continuous wavelet transformation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hasier, John; Nash, Philip [Thermal Processing Technology Center, IIT, Chicago, IL (United States); Riolo, Maria Annichia [University of Michigan, Center for the Study of Complex Systems, Ann Arbor, MI (United States)

    2017-12-15

    A cost effective method for conversion of a vertical tube thermogravimetric analysis system into a magnetic balance capable of measuring Curie Temperatures is presented. Reference and preliminary experimental data generated using this system is analyzed via a general-purpose wavelet based Curie point edge detection technique allowing for enhanced speed, ease and repeatability of magnetic balance data analysis. The Curie temperatures for a number of Heusler compounds are reported. (orig.)

  13. Multiple phase transitions in the generalized Curie-Weiss model

    International Nuclear Information System (INIS)

    Eisele, T.; Ellis, R.S.

    1988-01-01

    The generalized Curie-Weiss model is an extension of the classical Curie-Weiss model in which the quadratic interaction function of the mean spin value is replaced by a more general interaction function. It is shown that the generalized Curie-Weiss model can have a sequence of phase transitions at different critical temperatures. Both first-order and second-order phase transitions can occur, and explicit criteria for the two types are given. Three examples of generalized Curie-Weiss models are worked out in detail, including one example with infinitely many phase transitions. A number of results are derived using large-deviation techniques

  14. Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio

    International Nuclear Information System (INIS)

    MAjor, T.; Polgar, C.; Somogyi, A.; Nemeth, G.

    2000-01-01

    This study investigated the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and analyzed which implant parameters have influence on the DNR. Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined. Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR. In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but

  15. Evaluation of Patient Radiation Dose during Orthopedic Surgery

    International Nuclear Information System (INIS)

    Osman, H; Elzaki, A.; Sam, A.K.; Sulieman, A.

    2013-01-01

    The number of orthopedic procedures requiring the use of the fluoroscopic guidance has increased over the recent years. Consequently the patient exposed to un avoidable radiation doses. The aim of the current study was to evaluate patient radiation dose during these procedures.37 patients under went dynamic hip screw (DHS) and dynamic cannulated screw (DCS) were evaluated using calibrated Thermolumincent Dosimeters (TLDs), under carm fluoroscopic machines ,in three centers in Khartoum-Sudan. The mean Entrance Skin Dose (ESD) was 7.9 m Gy per procedure. The bone marrow and gonad organ exposed to significant doses. No correlation was found between ESD and Body Mass Index (BMI), or patient weight. Well correlation was found between kilo voltage applied and ESD. Orthopedic surgeries delivered lower radiation dose to patients than cardiac catheterization or hysterosalpingraphy (HSG) procedures. More study should be implemented to follow radiation dose before surgery and after surgery

  16. Evaluation of the absorbed dose in odontological computerized tomography

    International Nuclear Information System (INIS)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da; Khoury, Helen J.

    2011-01-01

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  17. Absorbed dose evaluations in retrospective dosimetry: Methodological developments using quartz

    DEFF Research Database (Denmark)

    Bailiff, I.K.; Bøtter-Jensen, L.; Correcher, V.

    2000-01-01

    Dose evaluation procedures based on luminescence techniques were applied to 50 quartz samples extracted from bricks that had been obtained from populated or partly populated settlements in Russia and Ukraine downwind of the Chernobyl NPP. Determinations of accrued dose in the range similar to 30...

  18. Marie Curie and the 'Science of Radioactivity'; Maria Curie y la 'Ciencia de la Radioactividad'

    Energy Technology Data Exchange (ETDEWEB)

    Mercader, Roberto C. [UNLP Universidad Nacional de La Plata, La Plata, Buenos Aires (Argentina); CONICET Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina)

    2009-07-01

    This article is about Maria Curie, nee Sklodowska, an outstanding mathematician and physicist who managed to counteract the oppressive rules in her Russian occupied Poland that prevented native Polish from taking advanced studies. She went to Paris to study physics and mathematics at the University at the end of the nineteenth century and, notwithstanding the harsh conditions she had to endure, she obtained honors degrees in both disciplines. After marrying her tutor, Pierre Curie, she and her husband were able to get to the core of the problem of {sup r}adioactivity{sup ,} term that she coined. They discovered two new elements, radium and polonium. Jointly with Becquerel, the Curies were awarded the Nobel Prize for physics in 1903. They kept on with their hard work together until the untimely dead of Pierre in 1906. Taking her husband's chair, she became the first female professor at La Sorbonne. In spite of the hostility toward her for sexist and xenophobic prejudices, she obtained a new Nobel Prize, this time for chemistry, in 1911. Her commitment to help the soldiers in the battlefields over the First World War was extraordinary. She developed portable X-ray machines and even drove herself the trucks that carried them to the field hospitals thus changing forever the way that war-inflicted wounds were treated. She founded the Institut du Radium where her daughter Irene obtained the Nobel Prize for physics in 1935 only months after her mother's dead of leukemia in 1934. (author)

  19. Radiation dose of CT coronary angiography in clinical practice: Objective evaluation of strategies for dose optimization

    International Nuclear Information System (INIS)

    Yerramasu, Ajay; Venuraju, Shreenidhi; Atwal, Satvir; Goodman, Dennis; Lipkin, David; Lahiri, Avijit

    2012-01-01

    Background: CT coronary angiography (CTCA) is an evolving modality for the diagnosis of coronary artery disease. Radiation burden associated with CTCA has been a major concern in the wider application of this technique. It is important to reduce the radiation dose without compromising the image quality. Objectives: To estimate the radiation dose of CTCA in clinical practice and evaluate the effect of dose-saving algorithms on radiation dose and image quality. Methods: Effective radiation dose was measured from the dose-length product in 616 consecutive patients (mean age 58 ± 12 years; 70% males) who underwent clinically indicated CTCA at our institution over 1 year. Image quality was assessed subjectively using a 4-point scale and objectively by measuring the signal- and contrast-to-noise ratios in the coronary arteries. Multivariate linear regression analysis was used to identify factors independently associated with radiation dose. Results: Mean effective radiation dose of CTCA was 6.6 ± 3.3 mSv. Radiation dose was significantly reduced by dose saving algorithms such as 100 kV imaging (−47%; 95% CI, −44% to −50%), prospective gating (−35%; 95% CI, −29% to −40%) and ECG controlled tube current modulation (−23%; 95% CI, −9% to −34%). None of the dose saving algorithms were associated with a significant reduction in mean image quality or the frequency of diagnostic scans (P = non-significant for all comparisons). Conclusion: Careful application of radiation-dose saving algorithms in appropriately selected patients can reduce the radiation burden of CTCA significantly, without compromising the image quality.

  20. Evaluation of worker's dose on a virtual dismantling environment

    International Nuclear Information System (INIS)

    Park, Hee Seong; Kim, Sung Hyun; Park, Byung Suk; Yoon, Ji Sup

    2007-01-01

    The motivation of this study is to provide a basis for a minimization of worker's dose during dismantling activities. In the present study, we proposed methods for identifying an existence of radioactivity which is contained in the dismantling objects and for evaluating a worker's dose under a virtual dismantling environment. To evaluate a worker's external dose, the shape of the exposure room in the KRR 2(Korean Research Reactor TRIGA MARK III) by 3D CAD was created and the radiation dose surrounding the facility by using MCNP- 4C(Monte Carlo N-Particle-4C) was calculated. The radiation field of the exposure room was visualized three dimensionally by using the radiation dose that was obtained by the code

  1. External contamination and skin dose. From ICRP and regulations to skin dose evaluation in practice

    International Nuclear Information System (INIS)

    Le Coulteulx, I.; Apretna, D.; Beaugerie, M.; Fenolland, J.; Frey, R.; Gonin, M.; Landry, B.; Laporte, E.; Le Guen, B.; Leval, D.

    2006-01-01

    Dose limitation to the skin is an objective of radiation protection. Our aim is to propose in case of skin contamination in EDF NPPs a simply, quickly and reproducible procedure for evaluating skin dose. French regulation admit an annual limit for skin dose over one square centimeter equal to 500 mSv. ICRP Publication 26 and 60 recommend that dose assessment be performed only if skin dose might be equal to or more than 50 mSv at basal cells. To respect this recommendation, an alert value (A) must be determined. This value is the lowest value of measurement from which dose assessment has to be made, based on the hypothesis that uninterrupted work time in controlled area is no more than four hours. This alert value (A) has been established for three external detection equipments, and for the ten radionuclides commonly detected. In case of external contamination, a first measurement is performed. If the value exceeds value (A), other measurements are instituted because skin dose evaluation needs to know other parameters as: - the radioactivity of the most contaminated square centimeter of the skin, - the identity of the radionuclides and their relative proportion. At the same time, we have to evaluate the length of the exposure. At last, we use different compiled results in a program developed from excel software which allow to calculate automatically the skin dose. This work has allowed us to publish an occupational health guideline about the assessment of skin dose in case of external contamination in EDF NPPs and to create an information booklet for workers. The authors propose to examine used methodology and to demonstrate the software. (authors)

  2. Dose evaluation for the public around the Tokai reprocessing plant

    International Nuclear Information System (INIS)

    Takeishi, Minoru; Furuta, Sadaaki; Miyabe, Kenjiro; Shinohara, Kunihiko

    2007-01-01

    The dose evaluations for the public around the Tokai Reprocessing Plant (TRP) have been carried out by using the mathematical models, because the effects on the environmental radiation due to the operation of the TRP are too small to separate from the background level. The models were developed by the site-specific investigations of the environment and reviewed in several times based on the latest scientific knowledge. The maximum annual effective dose through the whole period of the operation of the TRP was evaluated as 1.4 μSv with the data of the discharge monitoring and the meteorological observation in 1992. The evaluated doses revealed to be kept as far below the annual dose limit for the public as 1 mSv. (author)

  3. Using Population Dose to Evaluate Community-level Health Initiatives.

    Science.gov (United States)

    Harner, Lisa T; Kuo, Elena S; Cheadle, Allen; Rauzon, Suzanne; Schwartz, Pamela M; Parnell, Barbara; Kelly, Cheryl; Solomon, Loel

    2018-05-01

    Successful community-level health initiatives require implementing an effective portfolio of strategies and understanding their impact on population health. These factors are complicated by the heterogeneity of overlapping multicomponent strategies and availability of population-level data that align with the initiatives. To address these complexities, the population dose methodology was developed for planning and evaluating multicomponent community initiatives. Building on the population dose methodology previously developed, this paper operationalizes dose estimates of one initiative targeting youth physical activity as part of the Kaiser Permanente Community Health Initiative, a multicomponent community-level obesity prevention initiative. The technical details needed to operationalize the population dose method are explained, and the use of population dose as an interim proxy for population-level survey data is introduced. The alignment of the estimated impact from strategy-level data analysis using the dose methodology and the data from the population-level survey suggest that dose is useful for conducting real-time evaluation of multiple heterogeneous strategies, and as a viable proxy for existing population-level surveys when robust strategy-level evaluation data are collected. This article is part of a supplement entitled Building Thriving Communities Through Comprehensive Community Health Initiatives, which is sponsored by Kaiser Permanente, Community Health. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Problems arising in the evaluation of collective dose commitment

    International Nuclear Information System (INIS)

    Coulon, R.; Beau, P.

    1979-01-01

    In order to apply the concept of optimization it is necessary to evaluate the collective dose commitment for the population as a whole. This is found by summing the dose commitments for the different population groups involved, including persons occupationally exposed and members of the public both locally and globally. The average dose received by each of these groups can vary considerably: for occupational exposure it is about one order of magnitude below the limits, whereas for the general public it is far below, although certain local groups may be subjected to a much higher exposure than the overall average. The question arises, therefore, whether certain groups should not be weighted differently in order to take into account the heterogeneity of the distribution of exposure. As far as the validity of forecast evaluations is concerned, one may assume that for occupational exposure the dose commitment over the whole period of operation of a facility can be estimated fairly accurately. The overall collective dose commitment for the public is relatively insensitive to local variations in the environment and in the public itself but is strongly dependent on long-term developments which cannot at present be forecast. For the evaluation of dose equivalent to the critical group, local variations are of considerable importance and need to be foreseen, which is not always possible. By taking into account a period which includes the annual maximum collective dose equivalent one can make some of these difficulties less severe. (author)

  5. Maria Sklodowska-Curie - scientist, friend, manager

    Science.gov (United States)

    Slavchev, A.

    2009-01-01

    Great names in science represent an inexhaustible source and richness of inspiration, satisfaction and consolation, a moving and victorious force. Throughout her exemplifying life, Maria Sklodowska remained modest but with a keen sense of humor, of an outstanding style, a mine of knowledge and experience, of innovative ideas and a rich inner life. Full of love, of passion to give and to share, of natural optimism, mixed with a light melancholy, so typical for sages. She vehemently defended the love of scientific research, of the spirit of adventure and entrepreneurship and fought for international culture, for the protection of personality and talent. Maria Sklodowska left her passion to science, her dedication to work including education and training of young people, her passionate adherence to her family, her belief in her friends, her pure and profound humanity and warmth! The paper should be a homage to her, an appreciation of her work over the years, but not less a correspondence, a conversation with her! On the other hand, the present solemn occasion resuscitates the personalities of Maria and Pierre Curie and their work, in particular of Maria Sklodowska in her own native land! In this manner, it truly contributes to her immortality!

  6. Patient Doses and Risk Evaluation in Bone Mineral Densitometry

    International Nuclear Information System (INIS)

    Angelucci, M.; Borio, R.; Chiocchini, S.; Degli Esposti, P.; Dipilato, A.C.; Policani, G.

    1999-01-01

    The aim of this work was to evaluate the equipment dose to the organs and tissues and the effective dose of patients undergoing the most frequent examinations carried out in bone mineral densitometry (BMD): lumbar spine and femur. Experimental measurements of absorbed doses on a Rando phantom, allow comparison of the performances of three different photon emitter facilities. The comparison of the entrance and exit doses measured on a Rando phantom and on 50 female non-obese patients show that entrance doses on Rando can be used as 'diagnostic reference levels' for patients. A quantitative estimate of the stochastic risk due to BMD procedures was made: the results obtained show that the stochastic risk is very low and that the BMD is, at present, the most confirmed procedure for osteoporosis diagnosis and management. (author)

  7. Clinical implementation and evaluation of the Acuros dose calculation algorithm.

    Science.gov (United States)

    Yan, Chenyu; Combine, Anthony G; Bednarz, Greg; Lalonde, Ronald J; Hu, Bin; Dickens, Kathy; Wynn, Raymond; Pavord, Daniel C; Saiful Huq, M

    2017-09-01

    The main aim of this study is to validate the Acuros XB dose calculation algorithm for a Varian Clinac iX linac in our clinics, and subsequently compare it with the wildely used AAA algorithm. The source models for both Acuros XB and AAA were configured by importing the same measured beam data into Eclipse treatment planning system. Both algorithms were validated by comparing calculated dose with measured dose on a homogeneous water phantom for field sizes ranging from 6 cm × 6 cm to 40 cm × 40 cm. Central axis and off-axis points with different depths were chosen for the comparison. In addition, the accuracy of Acuros was evaluated for wedge fields with wedge angles from 15 to 60°. Similarly, variable field sizes for an inhomogeneous phantom were chosen to validate the Acuros algorithm. In addition, doses calculated by Acuros and AAA at the center of lung equivalent tissue from three different VMAT plans were compared to the ion chamber measured doses in QUASAR phantom, and the calculated dose distributions by the two algorithms and their differences on patients were compared. Computation time on VMAT plans was also evaluated for Acuros and AAA. Differences between dose-to-water (calculated by AAA and Acuros XB) and dose-to-medium (calculated by Acuros XB) on patient plans were compared and evaluated. For open 6 MV photon beams on the homogeneous water phantom, both Acuros XB and AAA calculations were within 1% of measurements. For 23 MV photon beams, the calculated doses were within 1.5% of measured doses for Acuros XB and 2% for AAA. Testing on the inhomogeneous phantom demonstrated that AAA overestimated doses by up to 8.96% at a point close to lung/solid water interface, while Acuros XB reduced that to 1.64%. The test on QUASAR phantom showed that Acuros achieved better agreement in lung equivalent tissue while AAA underestimated dose for all VMAT plans by up to 2.7%. Acuros XB computation time was about three times faster than AAA for VMAT plans, and

  8. Personal dosimetry statistics and specifics of low dose evaluation

    International Nuclear Information System (INIS)

    Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

    2015-01-01

    The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

  9. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography

    International Nuclear Information System (INIS)

    Lopes, Cintya Carolina Barbosa

    2006-04-01

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  10. Potential problems from shipment of high-curie content contact-handled transuranic (CH-TRU) waste to WIPP

    International Nuclear Information System (INIS)

    Neill, R.H.; Channell, J.K.

    1983-08-01

    There are about 1000 drums of contact-handled transuranic (CH-TRU) wastes containing more than 100 Ci/drum of Pu-238 that are stored at the Savannah River Plant and at the Los Alamos National Laboratory. Studies performed at DOE laboratories have shown that large quantities of gases are generated in stored drums containing 100 Ci of 238 Pu. Concentrations of hydrogen gas in the void space of the drums are often found to be high enough to be explosive. None of the analyses in the DOE WIPP Final Environmental Impact Statement, Safety Analysis Report, and Preliminary Transportation Analysis have considered the possibility that the generation of hydrogen gas by radiolysis may create an explosive or flammable hazard that could increase the frequency and severity of accidental releases of radionuclides during transportation or handling. These high 238 Pu concentration containers would also increase the estimated doses received by individuals and populations from transportation, WIPP site operations, and human intrusion scenarios even if the possibility of gas-enhanced releases is ignored. The WIPP Project Office has evaluated this effect on WIPP site operations and is suggesting a maximum limit of 140 239 Pu equivalent curies (P-Ci) per drum so that postulated accidental off-site doses will not be larger than those listed in the FEIS. The TRUPACT container, which is being designed for the transportation of CH-TRU wastes to WIPP, does not appear to meet the Nuclear Regulatory Commission regulations requiring double containment for the transportation of plutonium in quantities >20 Ci. A 20 alpha Ci/shipment limit would require about 200,000 shipments for the 4 million curies of alpha emitters slated for WIPP

  11. Measurement of spatial dose distribution for evaluation operator dose during nero-interventional procedures

    International Nuclear Information System (INIS)

    Han, Su Chul; Hong, Dong Hee

    2016-01-01

    The spatial dose distribution was measured with ionization chamber as preliminary study to evaluate operator dose and to study dose reduction during neuro-interventional procedures. The zone of operators was divided into four area (45, 135, 225, and 315 degree).We supposed that operator exist on the four area and indicated location of critical organs(eyes, breast, gonad). The spatial doses were measured depending on distance( 80, 100, 120, and 140 cm) and location of critical organs. The spatial doses of area of 225 degree were 114.5 mR/h (eyes location), 143.1 mR/h (breast location) and 147 mR/h (gonad location) in 80 cm. When changed location of x-ray generator, spatial dose increased in 18.1±10.5%, averagely. We certified spatial dose in the operator locations, Using the results of this study, It is feasible to protect operator from radiation in neuro-interventional procedures

  12. Measurement of spatial dose distribution for evaluation operator dose during nero-interventional procedures

    Energy Technology Data Exchange (ETDEWEB)

    Han, Su Chul [Division of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Hong, Dong Hee [Dept. of Radiology Science, Far East University, Eumseong (Korea, Republic of)

    2016-09-15

    The spatial dose distribution was measured with ionization chamber as preliminary study to evaluate operator dose and to study dose reduction during neuro-interventional procedures. The zone of operators was divided into four area (45, 135, 225, and 315 degree).We supposed that operator exist on the four area and indicated location of critical organs(eyes, breast, gonad). The spatial doses were measured depending on distance( 80, 100, 120, and 140 cm) and location of critical organs. The spatial doses of area of 225 degree were 114.5 mR/h (eyes location), 143.1 mR/h (breast location) and 147 mR/h (gonad location) in 80 cm. When changed location of x-ray generator, spatial dose increased in 18.1±10.5%, averagely. We certified spatial dose in the operator locations, Using the results of this study, It is feasible to protect operator from radiation in neuro-interventional procedures.

  13. Integral dose and evaluation of irradiated tissue volume

    International Nuclear Information System (INIS)

    Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

    1984-01-01

    Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

  14. Evaluation of radiation doses from MDCT-imaging in otolaryngology

    International Nuclear Information System (INIS)

    Yamauchi-Kawaura, C.; Fujii, K.; Aoyama, T.; Yamauchi, M.; Koyama, S.

    2009-01-01

    The purpose of this study was to clarify patient doses in the current otolaryngological multi-detector row computed tomography (MDCT) examinations. Patient doses were measured with an in-phantom dosimetry system which was composed of 48 photodiode dosemeters embedded within an anthropomorphic phantom. Organ and effective doses were evaluated according to the International Commission on Radiological Protection Publication 103. In neck CT, doses for salivary glands and for thyroid were high, 7.6-29.9 and 13.4-60.3 mGy, respectively. In sinus CT, brain and lens doses were high, 7.6-24.6 and 10.6-32.0 mGy, respectively, and in inner ear CT, lens dose was 8.0-35.3 mGy. Effective doses were 1.8-6.6 mSv in neck CT, 0.5-0.9 mSv in sinus CT and 0.3-0.6 mSv in inner ear CT. The present dose data would be used to estimate radiation risks for patients undergoing otolaryngological MDCT examinations. (authors)

  15. Evaluation of patient dose in some mammography centres in Iran

    International Nuclear Information System (INIS)

    Paknyat, A.; Samarin, E. R. P.; Jeshvaghane, N. A.; Paydar, R.; Fasaei, B.; Karamloo, A.; Khosravi, H. R.; Deevband, M. R.

    2011-01-01

    High diagnostic sensitivity and specificity while maintaining the least dose to the patient is the ideal mammography. The objective of this work was to evaluate patient dose and image quality of mammograms to propose corrective actions. The image quality for 1242 patient in 7 mammography facilities in Tehran city was evaluated based on selected image quality criteria using a three-point scale. Clinical image quality, the entrance surface air kerma, the average glandular dose and optical density of films for standard PMMA phantom of 4.5 cm thickness were evaluated. The results showed that up to 72 % of mammograms were in good condition to be diagnosed, and only about 3.4 % of the images were unacceptable or with suboptimal quality. The entrance surface air kerma values were in the range of 3.8-10.5 mGy, average glandular dose 0.5-1.8 mGy and optical density of films 0.74-2.03. The image quality evaluation after correction actions, periodic image quality evaluation and using the correct equipment certainly will improve patient dose. (authors)

  16. Magnetoresistance and Curie temperature of GaAs semiconductor doped with Mn ions

    International Nuclear Information System (INIS)

    Yalishev, V.Sh.

    2006-02-01

    Key words: diluted magnetic semiconductors, magnetoresistance, ferromagnetism, ionic implantation, molecular-beam epitaxy, magnetic clusters, Curie temperature. Subjects of the inquiry: Diluted magnetic semiconductor GaAs:Mn. Aim of the inquiry: determination of the possibility of the increase of Curie temperature in diluted magnetic semiconductors based on GaAs doped with Mn magnetic impurity. Method of inquiry: superconducting quantum interference device (SQUID), Hall effect, magnetoresistance, atomic and magnetic force microscopes. The results achieved and their novelty: 1. The effect of the additional doping of Ga 0,965 Mn 0,035 As magnetic epitaxial layers by nonmagnetic impurity of Be on on the Curie temperature was revealed. 2. The exchange interaction energy in the investigated Ga 0,965 Mn 0,035 As materials was determined by the means of the magnetic impurity dispersion model from the temperature dependence of the resistivity measurements. 3. The effect of magnetic clusters dimensions and illumination on the magnetoresistance of GaAs materials containing nano-dimensional magnetic clusters was studied for the first time. Practical value: Calculated energy of the exchange interaction between local electrons of magnetic ions and free holes in Ga 1-x Mn x As magnetic semiconductors permitted to evaluate the theoretical meaning of Curie temperature depending on concentration of free holes and to compare it with experimental data. Sphere of usage: micro- and nano-electronics, solid state physics, physics of semiconductors, magnetic materials physics, spin-polarized current sources. (author)

  17. Equivalent uniform dose concept evaluated by theoretical dose volume histograms for thoracic irradiation.

    Science.gov (United States)

    Dumas, J L; Lorchel, F; Perrot, Y; Aletti, P; Noel, A; Wolf, D; Courvoisier, P; Bosset, J F

    2007-03-01

    The goal of our study was to quantify the limits of the EUD models for use in score functions in inverse planning software, and for clinical application. We focused on oesophagus cancer irradiation. Our evaluation was based on theoretical dose volume histograms (DVH), and we analyzed them using volumetric and linear quadratic EUD models, average and maximum dose concepts, the linear quadratic model and the differential area between each DVH. We evaluated our models using theoretical and more complex DVHs for the above regions of interest. We studied three types of DVH for the target volume: the first followed the ICRU dose homogeneity recommendations; the second was built out of the first requirements and the same average dose was built in for all cases; the third was truncated by a small dose hole. We also built theoretical DVHs for the organs at risk, in order to evaluate the limits of, and the ways to use both EUD(1) and EUD/LQ models, comparing them to the traditional ways of scoring a treatment plan. For each volume of interest we built theoretical treatment plans with differences in the fractionation. We concluded that both volumetric and linear quadratic EUDs should be used. Volumetric EUD(1) takes into account neither hot-cold spot compensation nor the differences in fractionation, but it is more sensitive to the increase of the irradiated volume. With linear quadratic EUD/LQ, a volumetric analysis of fractionation variation effort can be performed.

  18. Dose evaluation for external exposure in radiation accidents

    International Nuclear Information System (INIS)

    Maruyama, Takashi

    1989-01-01

    Abnormal exposures including emergency and accidental are categorized into external exposure and internal contamination, although both of these may be associated with external contamination. From a point of view of lifesaving in the abnormal exposures, it is primarily important to evaluate radiation dose of exposed persons as soon as possible. This report reviews the status of early dosimetry in the accidental exposures and discusses the optimum methodology of the early dose determination for external exposures in abnormal exposures. Personal monitors generally give an indication of dose to an exposed person only at a single part of the body. The data obtained from the personal monitors should be interpreted with care and in the light of information about the circumstances of exposure. In most cases, the records of environmental monitors or the survey with area monitors provide valuable information on the radiation fields. In the some cases, the reconstruction of the abnormal exposure is required for the dose evaluation by means of phantom experiments. In the case of neutron exposures, activation products in the body or its components or personnel possession can be useful for the early dosimetry. If the dose received by the whole body is evaluated as being very high, clinical observations and biological investigations may be more important guide to initial medical treatment than the early dosimetry. For the dose evaluation of general public, depending on the size of abnormal exposure, information that could be valuable in the assessment of abnormal exposures will come from the early dose estimates with environmental monitors and radiation survey meters. (author)

  19. Evaluation of dose to cardiac structures during breast irradiation

    DEFF Research Database (Denmark)

    Aznar, M C; Korreman, S-S; Pedersen, A N

    2011-01-01

    delivered to the heart and the LAD in respiration-adapted radiotherapy of patients with left-sided breast cancer. METHODS: 24 patients referred for adjuvant radiotherapy after breast-conserving surgery for left-sided lymph node positive breast cancer were evaluated. The whole heart, the arch of the LAD...... and the whole LAD were contoured. The radiation doses to all three cardiac structures were evaluated. RESULTS: For 13 patients, the plans were acceptable based on the criteria set for all 3 contours. For seven patients, the volume of heart irradiated was well below the set clinical threshold whereas a high dose...

  20. A bust of Marie Sklodowska Curie at CERN

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The Polish Deputy Minister of Energy and Nuclear Power, J. Felicki, presented the Directors General with a bust of Mme Marie Sklodowska Curie on behalf of physicists of Poland (CERN Courier 19 (1979) 164).

  1. A jolly good call for Marie Curie Fellows

    CERN Multimedia

    2009-01-01

    A new funding opportunity to train young researchers has just been announced by the European Commission. One of the calls within FP7 Marie Curie Actions requests proposals for Initial Training Network (ITN) projects, with a deadline of 22 December 2009. Project proposals are strongly encouraged at CERN and authors can receive support and guidance from the Marie Curie Steering Group. Winnie Wong: "I wouldn’t have considered a PhD if I hadn’t been a Marie Curie fellow" Dan Savu: "It’s the best of both worlds: training plus working in an international organisation" ITN projects have one key aim: training. Academic and industrial partners work together to form a network to recruit and train Marie Curie Fellows. Fellows are young researchers (typically PhD-level) from any country who combine project-based research with tailor-made training programmes, ...

  2. Evaluation of the occupational dose in hemodynamic procedures

    International Nuclear Information System (INIS)

    Silva, Amanda J. da; Fernandes, Ivani M.; Sordi, Gian Maria A.A.; Carneiro, Janete C. Gaburo

    2010-01-01

    The purpose of this study was to evaluate the dose received by health professionals in a hemodynamic service. It was necessary to know the profile of these professional, to carry out a survey the occupational external doses during the years 2000 to 2009 and to evaluate the distribution of the effective dose from the special procedures guided by fluoroscopy. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account variables such as gender, age, individual monitoring time, number of jobs and tasks performed in the sector. In addition, it was performed an examination of the external individual monitoring doses from the records of the institution. The sample was composed of 35 professionals, 11 males and 24 females, with mean age of (43.0 +- 10.4) years. The average monitoring time of individuals analyzed within the institution was (11.3 +- 9.1) years, considering the period before the study. The minimum record dose level was 0.2 mSv and the maximum dose was 22.7 mSv. Doctors and nursing assistants were the professionals more exposed to radiation, due probably remaining closer to the examination table and X-ray tube during the interventional procedure. (author)

  3. Improvement of dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Onda, Takashi; Yoshida, Yoshitaka; Kudo, Seiichi; Nishimura, Kazuya

    2003-01-01

    It is expected that the selection of access routes for employees who engage in emergency work at a severe accident in a nuclear power plant makes a difference in their radiation dose values. In order to examine how much difference arises in the dose by the selection of the access routes, in the case of a severe accident in a pressurized water reactor plant, we improved the method to obtain the dose for employees and expanded the analyzing system. By the expansion of the system and the improvement of the method, we have realized the followings: (1) in the whole plant area, the dose evaluation is possible, (2) the efficiency of calculation is increased by the reduction of the number of radiation sources, etc, and (3) the function is improved by introduction of the sky shine calculation into the highest floor, etc. The improved system clarifies the followings: (1) the doses change by selected access routes, and this system can give the difference in the doses quantitatively, and (2) in order to suppress the dose, it is effective to choose the most adequate access route for the employees. (author)

  4. Properties of magnetocaloric materials with a distribution of Curie temperatures

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Bjørk, Rasmus; Smith, Anders

    2012-01-01

    The magnetocaloric properties of inhomogeneous ferromagnets that contain distributions of Curie temperatures are considered as a function of the width of such a distribution. Assuming a normal distribution of the Curie temperature, the average adiabatic temperature change, ΔTad, the isothermal...... of the distribution, explaining the observed mismatch of peak temperatures reported in experiments. Also, the field dependence of ΔTad and Δs is found to depend on the width of the distribution....

  5. From radioactivity to nuclear physics. Marie Curie and Lise Meitner

    International Nuclear Information System (INIS)

    Sime, R. L.

    1996-01-01

    In the first part of this century, at a time when few women obtained a higher education and even fewer entered the scientific professions, two exceptional women achieved great prominence in physics: Marie Curie in radioactivity and Lise Meitner in nuclear physics. In this article I outline the scientific work of meitner and Curie, in the context of their backgrounds and career paths that permitted them to overcome many of the obstacles faced by women in science. (author). 20 refs

  6. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Habiballah, B.; Abdelaziz, I.; Alzimami, K.; Osman, H.; Omer, H.; Sassi, S. A.

    2014-08-01

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  7. Evaluation of occupational and patient radiation doses in orthopedic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A. [Salman bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P.O. Box 422, Alkharj (Saudi Arabia); Habiballah, B.; Abdelaziz, I. [Sudan Univesity of Science and Technology, College of Medical Radiologic Sciences, P.O. Box 1908, Khartoum (Sudan); Alzimami, K. [King Saud University, College of Applied Medical Sciences, Radiological Sciences Department, P.O. Box 10219, 11433 Riyadh (Saudi Arabia); Osman, H. [Taif University, College of Applied Medical Science, Radiology Department, Taif (Saudi Arabia); Omer, H. [University of Dammam, Faculty of Medicine, Dammam (Saudi Arabia); Sassi, S. A., E-mail: Abdelmoneim_a@yahoo.com [Prince Sultan Medical City, Department of Medical Physics, Riyadh (Saudi Arabia)

    2014-08-15

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  8. Principles of protection: a formal approach for evaluating dose distributions

    International Nuclear Information System (INIS)

    Wikman-Svahn, Per; Peterson, Martin; Hansson, Sven Ove

    2006-01-01

    One of the central issues in radiation protection consists in determining what weight should be given to individual doses in relation to collective or aggregated doses. A mathematical framework is introduced in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. In addition to evaluation principles that are well known from radiation protection, a series of principles that are derived from parallel discussions in moral philosophy and welfare economics is investigated. A battery of formal properties is then used to investigate the evaluative principles. The results indicate that one of the new principles, bilinear prioritarianism, may be preferable to current practices, since it satisfies efficiency-related properties better without sacrificing other desirable properties

  9. Comparison of the dose evaluation methods for criticality accident

    International Nuclear Information System (INIS)

    Shimizu, Yoshio; Oka, Tsutomu

    2004-01-01

    The improvement of the dose evaluation method for criticality accidents is important to rationalize design of the nuclear fuel cycle facilities. The source spectrums of neutron and gamma ray of a criticality accident depend on the condition of the source, its materials, moderation, density and so on. The comparison of the dose evaluation methods for a criticality accident is made. Some methods, which are combination of criticality calculation and shielding calculation, are proposed. Prompt neutron and gamma ray doses from nuclear criticality of some uranium systems have been evaluated as the Nuclear Criticality Slide Rule. The uranium metal source (unmoderated system) and the uranyl nitrate solution source (moderated system) in the rule are evaluated by some calculation methods, which are combinations of code and cross section library, as follows: (a) SAS1X (ENDF/B-IV), (b) MCNP4C (ENDF/B-VI)-ANISN (DLC23E or JSD120), (c) MCNP4C-MCNP4C (ENDF/B-VI). They have consisted of criticality calculation and shielding calculation. These calculation methods are compared about the tissue absorbed dose and the spectrums at 2 m from the source. (author)

  10. Marie and Irene Curie. The first female Nobel Prize winners; Marie en IreneCurie. De eerste vrouwelijke Nobelprijswinnaars

    Energy Technology Data Exchange (ETDEWEB)

    Noordenbos, G. [Joke Smit Instituut voor Vrouwenstudies, Universiteit Leiden, Leiden (Netherlands)

    2003-07-01

    Marie Curie was awarded the Nobel Prize in 1903 and in 1911. Also her daughter, Irene Joliot-Curie, received a Nobel Prize for science in 1935. In this book an overview is given of the academic world at that time: limited access to universities for women, the carriers of both women in physics and their pioneering research and discoveries, the refusal of Marie Curie by the French Academy of Sciences, the awarding of the Nobel Prize and the assignment of Irene Joliot-Curie as the first female minister in France, the impact of the two World Wars, their married and private lives and the constant smear campaign of the press against both women. The lives and works of both women are hold against the light of the present position of women in physical sciences. [Dutch] In 1903, precies honderd jaar geleden, ontving Marie Curie als eerste vrouw de Nobelprijs voor de Wetenschap, gevolgd door een tweede Nobelprijs in 1911. Ook haar dochter Irene Joliot-Curie kreeg de Nobelprijs voor de wetenschap in 1935. Marie and Irene Curie schetst een breed beeld van de academische wereld waarin beide vrouwen zich bewogen: de beperkte toegang van vrouwen tot de universiteit, hun carrisres in de natuurkunde en baanbrekende ontdekkingen, de afwijzing van Marie door de Franse Academie des Sciences, de toekenning van de Nobelprijs en de benoeming van Irene als eerste vrouwelijke minister in Frankrijk, de invloed van de twee Wereldoorlogen, hun huwelijks- en priveleven en de niet aflatende hetze van de pers tegen beiden. In de door mannen gedomineerde wereld van de natuurwetenschappen liep de uitzonderingspositie van beide vrouwen als rode draad door hun curieuze levens. Het leven en werk van de Curies wordt geactualiseerd door deze tegen het licht te houden van de huidige positie van vrouwen in de natuurwetenschappen. Het bereiken van de top van de wetenschap door vrouwen blijkt nog steeds uitzonderlijk.

  11. Field study to evaluate radiation doses in dental practices

    International Nuclear Information System (INIS)

    Panzer, W.; Scheurer, C.

    1984-05-01

    An inexpensive and simple test device was developed and used in a field study to evaluate entrance dose, dose to an intra-oral film, filtration and field size under routine conditions in more than 150 dental practices. The test device consists of two films of different speed and a set of 5 thin copper filters for a filter analytical determination of the radiation quality. Dentists voluntarily participating in the study were asked to expose the test device like they usually do when examining a molar tooth. The main result was the evidence of a significant dose reduction compared to the findings of similar studies performed in 1970 and 1976. This reduction is due to a general shift to lower values and a complete disappearance of values above 45 mGy (5 R) which in 1970 were still more than 15%. In the same way the number of facilities showing insufficient filtration or collimation had decreased. Nevertheless, a large spread of dose values could still be observed, ranging from less than 0.45 mGy (50 mR) to more than 26 mGy (3 R), for the entrance dose. The most striking result, however, was that such an important parameter like the speed of the films used at the respective unit turned out to have no impact on the entrance dose. (orig./HP)

  12. The Curie Museum - The Curie family, Radioactivity in few dates, The struggle against cancer: the history of radiotherapy

    International Nuclear Information System (INIS)

    2015-01-01

    This publication first proposes a chronology of the main events of Marie Curie's and Pierre Curie's lives, describes how they met and started their research works, how she kept on working after Pierre's death, how she got a laboratory (the Radium Institute) built by the Paris University and Pasteur Institute, her work during the first Wold War. The second part briefly describes her life from her birth in Warsaw to her death in Paris. The third part addresses the lives of Irene and Frederic Joliot-Curie. It recalls how Frederic Joliot met Marie Curie and her daughter, and their common work. It notably recalls the discovery of artificial radioactivity, the issue of heavy water at the beginning of the war, the political commitment of Frederic Joliot, his role in the construction of the first French atomic pile. The fourth part indicates the chronology of the evolution of the Radium Institute which became the Curie Institute, until the creation of the Curie Museum. The fifth part indicates the key dates of the history of knowledge on radioactivity, from 1895 (discovery of X rays by Roentgen) to 1939 (demonstration of the possibility of a chain reaction). The sixth part addresses the first medical applications of radiations during almost the same period. Light is then shed on Claudius Regaud (1870-1940) who was a pioneer in radiotherapy and a founder of modern oncology: a chronology is given and a text reports his scientific life

  13. Joliot-Curie School of Nuclear Physics, 1997; Ecole Joliot-Curie de Physique Nucleaire, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, Y. [L`Institut National de Physique Nucleaire et de Physique des Particules du CNRS (India2P3), 75 - Paris (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    This document contains the lectures of the Joliot-Curie International School of Nuclear Physics held at Maubuisson, France on 8-13 September 1997. The following lectures of nuclear interest were given: The N-body problem (relativistic and non-relativistic approaches); The shell model (towards a unified of the nuclear structure); Pairing correlations in extreme conditions; Collective excitations in nuclei; Exotic nuclei (production, properties and specificities); Exotic nuclei (halos); Super and hyper deformation (from discrete to continuum, from EUROGAM to EUROBALL); and The spectroscopy of fission fragments. Important new facts are reported and discussed theoretically, concerning the nuclei in high excitation and high states and of the nuclei far off stability. Important technical achievements are reported among which the production of radioactive beams, sophisticated multi-detectors as well as significant advances in the nuclear theoretical methods. The double goal of training of young researchers and of permanent formation and information of the older ones seems to have been reached

  14. Joliot-Curie School of Nuclear Physics, 1997; Ecole Joliot-Curie de Physique Nucleaire, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, Y [L` Institut National de Physique Nucleaire et de Physique des Particules du CNRS (India2P3), 75 - Paris (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1999-12-31

    This document contains the lectures of the Joliot-Curie International School of Nuclear Physics held at Maubuisson, France on 8-13 September 1997. The following lectures of nuclear interest were given: The N-body problem (relativistic and non-relativistic approaches); The shell model (towards a unified of the nuclear structure); Pairing correlations in extreme conditions; Collective excitations in nuclei; Exotic nuclei (production, properties and specificities); Exotic nuclei (halos); Super and hyper deformation (from discrete to continuum, from EUROGAM to EUROBALL); and The spectroscopy of fission fragments. Important new facts are reported and discussed theoretically, concerning the nuclei in high excitation and high states and of the nuclei far off stability. Important technical achievements are reported among which the production of radioactive beams, sophisticated multi-detectors as well as significant advances in the nuclear theoretical methods. The double goal of training of young researchers and of permanent formation and information of the older ones seems to have been reached

  15. Two gamma dose evaluation methods for silicon semiconductor detector

    International Nuclear Information System (INIS)

    Chen Faguo; Jin Gen; Yang Yapeng; Xu Yuan

    2011-01-01

    Silicon PIN diodes have been widely used as personal and areal dosimeters because of their small volume, simplicity and real-time operation. However, because silicon is neither a tissue-equivalent nor an air-equivalent material, an intrinsic disadvantage for silicon dosimeters is that a significant over-response occurs at low-energy region, especially below 200 keV. Using a energy compensation filter to flatten the energy response is one method overcoming this disadvantage. But for dose compensation method, the estimated dose depends only on the number of the detector pulses. So a weight function method was introduced to evaluate gamma dose, which depends on pulse number as well as its amplitude. (authors)

  16. Evaluation of dose exposure in 64-slice CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M. [University Hospital Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany); Buchgeister, M.; Klabunde, M. [University of Tuebingen, Institute of Medical Physics, Tuebingen (Germany)

    2007-10-15

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

  17. Evaluation of dose exposure in 64-slice CT colonography

    International Nuclear Information System (INIS)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M.; Buchgeister, M.; Klabunde, M.

    2007-01-01

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

  18. Experimental evaluation of a MOSFET dosimeter for proton dose measurements

    International Nuclear Information System (INIS)

    Kohno, Ryosuke; Nishio, Teiji; Miyagishi, Tomoko; Hirano, Eriko; Hotta, Kenji; Kawashima, Mitsuhiko; Ogino, Takashi

    2006-01-01

    The metal oxide semiconductor field-effect transistor (MOSFET) dosimeter has been widely studied for use as a dosimeter for patient dose verification. The major advantage of this detector is its size, which acts as a point dosimeter, and also its ease of use. The commercially available TN502RD MOSFET dosimeter manufactured by Thomson and Nielsen has never been used for proton dosimetry. Therefore we used the MOSFET dosimeter for the first time in proton dose measurements. In this study, the MOSFET dosimeter was irradiated with 190 MeV therapeutic proton beams. We experimentally evaluated dose reproducibility, linearity, fading effect, beam intensity dependence and angular dependence for the proton beam. Furthermore, the Bragg curve and spread-out Bragg peak were also measured and the linear-energy transfer (LET) dependence of the MOSFET response was investigated. Many characteristics of the MOSFET response for proton beams were the same as those for photon beams reported in previous papers. However, the angular MOSFET responses at 45, 90, 135, 225, 270 and 315 degrees for proton beams were over-responses of about 15%, and moreover the MOSFET response depended strongly on the LET of the proton beam. This study showed that the angular dependence and LET dependence of the MOSFET response must be considered very carefully for quantitative proton dose evaluations

  19. Idaho National Engineering Laboratory historical dose evaluation: Volume 1

    International Nuclear Information System (INIS)

    Francis, S.J.

    1991-08-01

    The methodology and results are presented for an evaluation of potential radiation doses to a hypothetical individual who may have resided at an offsite location with the highest concentration of airborne radionuclides near the Idaho National Engineering Laboratory (INEL). Volume 1 contains a summary of methods and results. The years of INEL operations from 1952 to 1989 were evaluated. Radiation doses to an adult, child, and infant were estimated for both operational (annual) and episodic (short-term) airborne releases from INEL facilities. Atmospheric dispersion of operational releases was modeled using annual average meteorological conditions. Dispersion of episodic releases was generally modeled using actual hourly wind speed and direction data at the time of release. 50 refs., 23 figs., 10 tabs

  20. Evaluation of environmental radiation dose in Ibaraki Prefecture

    International Nuclear Information System (INIS)

    Koike, Ryoji

    1977-01-01

    In Ibaraki Prefecture, there is Environmental Radioactivity Surveillance Committee in order to ensure the safety around nuclear power facilities. Environmental radioactivity data are collected every three months, and the grasp of the present situation, the clarification of causes, the evaluation of dose and the publication of results are made. Two instances in particular are described: of contamination paddies due to 14 C contained in drainage; contamination of rivers due to U contained in drainage. (Mori, K.)

  1. CT-stereotactic interstitial Curie-therapy using iodine-125 seeds in inoperable brain tumours

    International Nuclear Information System (INIS)

    Mundinger, F.

    1985-01-01

    Iodine-125 seeds are a new radio-drug featuring favourable physical, biological and radiation protection characteristics and available for interstitial (local) irradiation (Curie-therapy) of non-resectable brain tumours as such (cerebral tumours) or of tumours of the interior of the neuro-cranium (extracerebral tumours). Emitters are inserted right into the tumour or tumour recurrence by means of computerized-tomography stereotaxy either permanently or temporarily with dose release being largely restricted to the tumour and the surrounding brain tissue being spared. (orig.) [de

  2. Frederic Joliot-Curie and the nuclear weapon

    International Nuclear Information System (INIS)

    Pinault, M.

    2000-01-01

    The author describes the attitude and action of Pierre Joliot-Curie after the explosion of the first nuclear bomb in Hiroshima and during the following years. He notably describes the creation of the French CEA (Commissariat a l'Energie Atomique), the commitment of Joliot-Curie for the creation of a scientist movement, the atomic negotiation within the United Nations, the creation and actions of the Mouvement de la Paix (from April 1949 until the Stockholm Appeal) within the Cold War context, the commitment of Joliot-Curie against weapons of mass destruction and its difficult relationship with his communists friends, his participation to the elaboration of the Einstein-Russel Appeal, and the Pugwash conference in 1957

  3. Maria Sklodowska Curie - the precursor of radiation sterilization methods

    Energy Technology Data Exchange (ETDEWEB)

    Gluszewski, Wojciech; Zagorski, Zbigniew P. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Tran, Quoc Khoi; Cortella, Laurent [CEA Grenoble, ARC-Nucleart, Atelier Regional de Conservation, Grenoble (France)

    2011-06-15

    A resolution of the 63rd Assembly of the United Nations proclaimed the year 2011 as the International Year of Chemistry. The coordinators of the event are UNESCO and the International Union of Pure and Applied Chemistry (IUPAC). The patroness of this event is Marie Curie, nee Sklodowska. Among women scientists, she was the first recipient of the Novel Prize, and among all scientists, she is the only one who has received this award in different scientific fields (in 1903 in the field of physics with Pierre Curie and Henri Becquerel, in 1911 in the field of chemistry). Considering the former Polish nationality of Marie Curie, the year 2011 has been proposed by the Polish Parliament as her year, using the name Maria Sklodowska Curie, under which she is known in Poland. Celebrating the International Year of Chemistry is a good opportunity to remember the importance of the work of Maria Sklodowska Curie for the emergence and development of many fields of science. This article is an attempt to present a view of science, as taught through modern applications of the radiation chemistry of polymetric materials and radiation sterilization. Although the real development of both ''cold'' sterilization and polymer technology occurred in the 1950's long after the death of Marie Curie Sklodowska, the original ideas go back to ther work performed in the 1920s. Sometimes, and that is the present case, a single scientist creates a new field, in spite of the fact that at the time of discovery there are no applications. The parallel development of other branches of science and technology helps the application of the original idea. (orig.)

  4. Maria Sklodowska Curie - the precursor of radiation sterilization methods

    International Nuclear Information System (INIS)

    Gluszewski, Wojciech; Zagorski, Zbigniew P.; Tran, Quoc Khoi; Cortella, Laurent

    2011-01-01

    A resolution of the 63rd Assembly of the United Nations proclaimed the year 2011 as the International Year of Chemistry. The coordinators of the event are UNESCO and the International Union of Pure and Applied Chemistry (IUPAC). The patroness of this event is Marie Curie, nee Sklodowska. Among women scientists, she was the first recipient of the Novel Prize, and among all scientists, she is the only one who has received this award in different scientific fields (in 1903 in the field of physics with Pierre Curie and Henri Becquerel, in 1911 in the field of chemistry). Considering the former Polish nationality of Marie Curie, the year 2011 has been proposed by the Polish Parliament as her year, using the name Maria Sklodowska Curie, under which she is known in Poland. Celebrating the International Year of Chemistry is a good opportunity to remember the importance of the work of Maria Sklodowska Curie for the emergence and development of many fields of science. This article is an attempt to present a view of science, as taught through modern applications of the radiation chemistry of polymetric materials and radiation sterilization. Although the real development of both ''cold'' sterilization and polymer technology occurred in the 1950's long after the death of Marie Curie Sklodowska, the original ideas go back to ther work performed in the 1920s. Sometimes, and that is the present case, a single scientist creates a new field, in spite of the fact that at the time of discovery there are no applications. The parallel development of other branches of science and technology helps the application of the original idea. (orig.)

  5. Mathematical model for evaluation of dose-rate effect on biological responses to low dose γ-radiation

    International Nuclear Information System (INIS)

    Ogata, H.; Kawakami, Y.; Magae, J.

    2003-01-01

    Full text: To evaluate quantitative dose-response relationship on the biological response to radiation, it is necessary to consider a model including cumulative dose, dose-rate and irradiation time. In this study, we measured micronucleus formation and [ 3 H] thymidine uptake in human cells as indices of biological response to gamma radiation, and analyzed mathematically and statistically the data for quantitative evaluation of radiation risk at low dose/low dose-rate. Effective dose (ED x ) was mathematically estimated by fitting a general function of logistic model to the dose-response relationship. Assuming that biological response depends on not only cumulative dose but also dose-rate and irradiation time, a multiple logistic function was applied to express the relationship of the three variables. Moreover, to estimate the effect of radiation at very low dose, we proposed a modified exponential model. From the results of fitting curves to the inhibition of [ 3 H] thymidine uptake and micronucleus formation, it was obvious that ED 50 in proportion of inhibition of [ 3 H] thymidine uptake increased with longer irradiation time. As for the micronuclei, ED 30 also increased with longer irradiation times. These results suggest that the biological response depends on not only total dose but also irradiation time. The estimated response surface using the three variables showed that the biological response declined sharply when the dose-rate was less than 0.01 Gy/h. These results suggest that the response does not depend on total cumulative dose at very low dose-rates. Further, to investigate the effect of dose-rate within a wider range, we analyzed the relationship between ED x and dose-rate. Fitted curves indicated that ED x increased sharply when dose-rate was less than 10 -2 Gy/h. The increase of ED x signifies the decline of the response or the risk and suggests that the risk approaches to 0 at infinitely low dose-rate

  6. Robust ray-tracing algorithms for interactive dose rate evaluation

    International Nuclear Information System (INIS)

    Perrotte, L.

    2011-01-01

    More than ever, it is essential today to develop simulation tools to rapidly evaluate the dose rate received by operators working on nuclear sites. In order to easily study numerous different scenarios of intervention, computation times of available softwares have to be all lowered. This mainly implies to accelerate the geometrical computations needed for the dose rate evaluation. These computations consist in finding and sorting the whole list of intersections between a big 3D scene and multiple groups of 'radiative' rays meeting at the point where the dose has to be measured. In order to perform all these computations in less than a second, we first propose a GPU algorithm that enables the efficient management of one big group of coherent rays. Then we present a modification of this algorithm that guarantees the robustness of the ray-triangle intersection tests through the elimination of the precision issues due to floating-point arithmetic. This modification does not require the definition of scene-dependent coefficients ('epsilon' style) and only implies a small loss of performance (less than 10%). Finally we propose an efficient strategy to handle multiple ray groups (corresponding to multiple radiative objects) which use the previous results.Thanks to these improvements, we are able to perform an interactive and robust dose rate evaluation on big 3D scenes: all of the intersections (more than 13 million) between 700 000 triangles and 12 groups of 100 000 rays each are found, sorted along each ray and transferred to the CPU in 470 milliseconds. (author) [fr

  7. Frederic Joliot-Curie and the nuclear weapon; Frederic Joliot-Curie et l'arme atomique

    Energy Technology Data Exchange (ETDEWEB)

    Pinault, M.

    2000-07-01

    The author describes the attitude and action of Pierre Joliot-Curie after the explosion of the first nuclear bomb in Hiroshima and during the following years. He notably describes the creation of the French CEA (Commissariat a l'Energie Atomique), the commitment of Joliot-Curie for the creation of a scientist movement, the atomic negotiation within the United Nations, the creation and actions of the Mouvement de la Paix (from April 1949 until the Stockholm Appeal) within the Cold War context, the commitment of Joliot-Curie against weapons of mass destruction and its difficult relationship with his communists friends, his participation to the elaboration of the Einstein-Russel Appeal, and the Pugwash conference in 1957

  8. Evaluating the maximum patient radiation dose in cardiac interventional procedures

    International Nuclear Information System (INIS)

    Kato, M.; Chida, K.; Sato, T.; Oosaka, H.; Tosa, T.; Kadowaki, K.

    2011-01-01

    Many of the X-ray systems that are used for cardiac interventional radiology provide no way to evaluate the patient maximum skin dose (MSD). The authors report a new method for evaluating the MSD by using the cumulative patient entrance skin dose (ESD), which includes a back-scatter factor and the number of cine-angiography frames during percutaneous coronary intervention (PCI). Four hundred consecutive PCI patients (315 men and 85 women) were studied. The correlation between the cumulative ESD and number of cine-angiography frames was investigated. The irradiation and overlapping fields were verified using dose-mapping software. A good correlation was found between the cumulative ESD and the number of cine-angiography frames. The MSD could be estimated using the proportion of cine-angiography frames used for the main angle of view relative to the total number of cine-angiography frames and multiplying this by the cumulative ESD. The average MSD (3.0±1.9 Gy) was lower than the average cumulative ESD (4.6±2.6 Gy). This method is an easy way to estimate the MSD during PCI. (authors)

  9. Evaluation of a low-dose neonatal chest radiographic system

    International Nuclear Information System (INIS)

    Burton, E.M.; Kirks, D.R.; Strife, J.L.; Henry, G.C.; Kereiakes, J.G.

    1988-01-01

    A new low-dose chest radiographic system for use in the neonatal nursery was evaluated. This test system, composed of a Du Pont Kevlar fiber-front cassette, Quanta fast-detail screen, Cronex 4L film (wide latitude), and additional yttrium filtration (0.1 mm), reduced the radiation dose in neonatal chest radiography by 69% (0.9 vs 2.9 mrad [0.009 vs 0.029 mGy]) as compared with a conventional system without added yttrium filtration; the thyroid dose was reduced by 76% (0.9 vs 3.7 mrad [0.009 vs 0.037 mGy]). The cumulative dose reduction was achieved through a combination of factors, including (1) beam hardening by the added yttrium filter, (2) increased X-ray transmission through the Kevlar cassette, and (3) a fast film-screen combination. Scatter radiation at distances of 1 and 6 ft. (0.3 and 1.8 m) was negligible for both systems. Image sharpness was compared for the conventional system with and without added yttrium filtration and for the Kevlar system with yttrium. Although sharpness of bony detail was unchanged by adding yttrium filtration to the conventional system, a decrease in sharpness was noted with the Kevlar system. Because image sharpness was affected in the test system, we are not using the Kevlar-Cronex 4L system for mobile chest radiography in the neonatal intensive care unit, despite dose reductions. However, further study is recommended to determine if there is a slower film-screen combination with yttrium filtration that will not degrade image sharpness

  10. Dose Evaluation and Quality Criteria in Dental Radiology

    International Nuclear Information System (INIS)

    Gori, C.; Rossi, F.; Stecco, A.; Villari, N.; Zatelli, G.

    2000-01-01

    Radioprotection in dental radiology is of particular interest in the framework of the Revised Medical Exposure Directive for the great number of examinations involving the adult as well as the paediatric population (Article 9: Special Practice). The present study is intended to find the quality criteria of orthodontic imaging and for evaluating the dose absorbed within the dental and maxillary volume in connection with radiological examinations performed with either spiral CT, dental panoramic tomography or teleradiography. The X ray dose to organs sited in the body, neck, ocular and intracranial area was measured using lithium fluoride dosemeters, positioned in a Rando phantom. Quality criteria have been established by an expert radiologist considering the diagnostic information obtained in the images. The dosimetric data obtained were comparable with other authors', although with some differences due to technical characteristics. These result data are useful for choosing the patient's diagnostic path, considering the radiobiological risk associated with increasing orthodontic imaging. (author)

  11. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    International Nuclear Information System (INIS)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in μSv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  12. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-03-15

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in {mu}Sv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  13. Marie Sklodowska-Curie, polonium, radium and radiochemistry

    International Nuclear Information System (INIS)

    Guillaumont, R.

    2011-01-01

    In this work, the author describes how the methodology developed by Marie Curie in discovering polonium and radium has contributed to greater scientific discoveries and how these discoveries have played a great part in the development of science in general and have particularly enriched chemistry. (O.M.)

  14. Envisioning science : Marie Curie's journey from Poland to Paris

    International Nuclear Information System (INIS)

    Odlin, S.; Fleming, J.S.

    2011-01-01

    Marya Sklodovska (nicknamed Manya), born November 1867, was the fifth and youngest child in the Sklodovski family. Marie Curie epitomised the ability to be beautifully creative. Her pioneering spirit gave her the drive to become one of the first women to gain an education, and qualifications, in the sciences. 5 refs., 1 fig.

  15. Dynamics of quantum measurements employing two Curie-Weiss apparatuses

    Science.gov (United States)

    Perarnau-Llobet, Martí; Nieuwenhuizen, Theodorus Maria

    2017-10-01

    Two types of quantum measurements, measuring the spins of an entangled pair and attempting to measure a spin at either of two positions, are analysed dynamically by apparatuses of the Curie-Weiss type. The outcomes comply with the standard postulates. This article is part of the themed issue `Second quantum revolution: foundational questions'.

  16. Radiation dose evaluation in patients submitted to conventional radiological examinations

    International Nuclear Information System (INIS)

    Tilly Junior, Joao G.

    1997-01-01

    This work presents the results of the evaluation of radiation dose delivered to the patients undergoing conventional radiological procedures. Based in the realized measurement some indicators are settled to quantitative appraisal of the radiological protection conditions offered to the population. Data assessment was done in the county of Curitiba, in Parana State, Brazil, from 12/95 to 04/96, in ten rooms of three different institutions, under 101 patients, adults with 70 ± 10 kg, during real examinations of chest PA, chest LAT and abdomen AP. (author)

  17. [Evaluation of methods to calculate dialysis dose in daily hemodialysis].

    Science.gov (United States)

    Maduell, F; Gutiérrez, E; Navarro, V; Torregrosa, E; Martínez, A; Rius, A

    2003-01-01

    Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiological. Different methods have been described to calculate dialysis dose which take into consideration change in frequency. The aim of this study was to calculate all dialysis dose possibilities and evaluate the better and practical options. Eight patients, 6 males and 2 females, on standard 4 to 5 hours thrice weekly on-line hemodiafiltration (S-OL-HDF) were switched to daily on-line hemodiafiltration (D-OL-HDF) 2 to 2.5 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Time average concentration (TAC), time average deviation (TAD), normalized protein catabolic rate (nPCR), Kt/V, equilibrated Kt/V (eKt/V), equivalent renal urea clearance (EKR), standard Kt/V (stdKt/V), urea reduction ratio (URR), hemodialysis product and time off dialysis were measured. Daily on-line hemodiafiltration was well accepted and tolerated. Patients maintained the same TAC although TAD decreased from 9.7 +/- 2 in baseline to a 6.2 +/- 2 mg/dl after six months, p time off dialysis was reduced to half. Dialysis frequency is an important urea kinetic parameter which there are to take in consideration. It's necessary to use EKR, stdKt/V or weekly URR to calculate dialysis dose for an adequate comparison between different frequency dialysis schedules.

  18. Extracranial stereotactic radiotherapy: Evaluation of PTV coverage and dose conformity

    International Nuclear Information System (INIS)

    Haedinger, U.; Thiele, W.; Wulf, J.

    2002-01-01

    During the past few years the concept of cranial sterotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3%±2.3% (lung), 95.0%±4.5% (liver), and 92.1%±5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73±0.09 (lung), 0.77±0.10 (liver), and 0.70±0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields. (orig.) [de

  19. A study of different dose calculation methods and the impact on the dose evaluation protocol in lung stereotactic radiation therapy

    International Nuclear Information System (INIS)

    Takada, Takahiro; Furuya, Tomohisa; Ozawa, Shuichi; Ito, Kana; Kurokawa, Chie; Karasawa, Kumiko; Miura, Kohei

    2008-01-01

    AAA (analytical anisotropic algorithm) dose calculation, which shows a better performance for heterogeneity correction, was tested for lung stereotactic radiation therapy (SBRT) in comparison to conventional PBC (pencil beam convolution method) to evaluate its impact on tumor dose parameters. Eleven lung SBRT patients who were treated with photon 4 MV beams in our department between April 2003 and February 2007 were reviewed. Clinical target volume (CTV) was delineated including the spicula region on planning CT images. Planning target volume (PTV) was defined by adding the internal target volume (ITV) and set-up margin (SM) of 5 mm from CTV, and then an multileaf collimator (MLC) penumbra margin of another 5 mm was also added. Six-port non-coplanar beams were employed, and a total prescribed dose of 48 Gy was defined at the isocenter point with four fractions. The entire treatment for an individual patient was completed within 8 days. Under the same prescribed dose, calculated dose distribution, dose volume histogram (DVH), and tumor dose parameters were compared between two dose calculation methods. In addition, the fractionated prescription dose was repeatedly scaled until the monitor units (MUs) calculated by AAA reached a level of MUs nearly identical to those achieved by PBC. AAA resulted in significantly less D95 (irradiation dose that included 95% volume of PTV) and minimal dose in PTV compared to PBC. After rescaling of each MU for each beam in the AAA plan, there was no revision of the isocenter of the prescribed dose required. However, when the PTV volume was less than 20 cc, a 4% lower prescription resulted in nearly identical MUs between AAA and PBC. The prescribed dose in AAA should be the same as that in PBC, if the dose is administered at the isocenter point. However, planners should compare DVHs and dose distributions between AAA and PBC for a small lung tumor with a PTV volume less than approximately 20 cc. (author)

  20. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  1. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  2. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    International Nuclear Information System (INIS)

    Rampado, Osvaldo; Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto; Fiandra, Christian; Ragona, Riccardo

    2016-01-01

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution in an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K_a_i_r), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ doses

  3. Special Workshop of Marie Curie Fellows on Research and Training in Physics and Technology

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    Photo 0210004_1: Prof. Ugo Amaldi, University of Milano Bicocca and Tera Foundation, Italy. Addressing the Marie Curie Workshop held at CERN 3-4 October 2002. Title of this talk:"Research Developments on Medical Physics". Photo 0210004_2: Marie Curie Fellows at CERN. Participating in Marie Curie Workshop held at CERN 3-4 October 2002.

  4. Images of Marie Curie: How Reputational Entrepreneurs Shape Iconic Identities

    Directory of Open Access Journals (Sweden)

    Lisa Alaimo

    2018-03-01

    Full Text Available Marie Curie holds iconic status both within the scientific community and in the wider cultural imagination and collective memory. The first woman to be awarded a Nobel Prize and the only woman to achieve such an honor twice, Curie is widely celebrated as a female pioneer in the sciences and is held up as a model for all, but particularly women, to emulate. She is revered not only as a ground-breaking scientist, but also as a devoted wife and mother who fostered intellectual passion in her own children, one of whom became the second woman to be honored with the Nobel Prize in Science. Echoing Eva Hemmungs Wirten, we argue that the evolution of Curie’s status over time offers an opportunity to use meta-biography to understand the layered nature of her reputation. We draw on Gary Alan Fine’s theory of reputational entrepreneurship to understand her legacy as a product of collective historical memory. Curie’s legacy was not pre-determined by the fact that she was a successful scientist; in fact, she was shunned by the public in France in 1911 after it was revealed that she, a widow, had engaged in an affair with a fellow married scientist. A meta-biographical analysis reveals considerable effort was put into reputation building by her Curie herself, her commercial sponsor, and family members. To ignore the earlier iterations of her reputation is to underestimate the challenges she faced as a woman in male-dominated science and in a society that judged her by a sexual double standard. Meta-biography, in conjunction with theories of intellectual reputation building and collective memory, allows us to unearth the complicated layers of Curie’s story. It also tells us a great deal about the [sexist] society in which Curie and her supporters had to forge her reputation.

  5. Curie temperature trends in (III, Mn)V ferromagnetic semiconductors

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Tomáš; König, J.; Sinova, J.; Kučera, Jan; MacDonald, A. H.

    2002-01-01

    Roč. 66, č. 1 (2002), s. 012402-1-012402-4 ISSN 0163-1829 R&D Projects: GA MŠk OC P5.10; GA ČR GA202/02/0912 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * Curie temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.327, year: 2002

  6. Evaluation of radiological doses to the terrestrial plants around Trombay

    International Nuclear Information System (INIS)

    Ajay Kumar; Singhal, R.K.; Preetha, J.; Joshi, S.N.; Hegde, A.G.

    2005-01-01

    Existing policies for radiation protection do not provide explicit criteria for the protection of species other than humans, i.e. not for flora and fauna. Concern over this omission is now being widely expressed and moves are under way to evaluate the doses to terrestrial and aquatic biota. During the present work radiological doses (external and internal) to the terrestrial plants were evaluated by estimating the concentration of anthropogenic ( 137 Cs, 90 Sr) and natural radionuclides ( 238 U, 232 Th and 40 K) in the plant leaves and by measuring the external gamma radiation due to different radionuclide. The soil and vegetation sample were collected from fifteen sampling locations around the different locations at Trombay. The samples were processed as per IAEA (International Atomic Energy Agency) protocol for the estimation of naturally occurring and anthropogenic radionuclides in soil and terrestrial plants. The gamma emitting radionuclides were measured by high resolution gamma (HPGe) spectrometry system. Maximum exposure (external + internal) to the terrestrial plants was observed due to 232 Th while 238 U showed minimum exposure. The average value of radiation exposure to the terrestrial plants for 40 K, 137 Cs, 90 Sr, 238 U and 232 Th was 1555.2 ± 92.4, 691.2 ± 54.3, 2564.1 ± 534.9, 82.5 ±5.2, and 4419.6 ± 1165.5 μGy/y respectively. The radiation exposure (external + internal ) to the terrestrial plants due to all radionuclides was found within the permissible limits (i.e. 10 mGy/d) as per recommended by the United States, Department of Energy (DOE). (author)

  7. Exhibition: Life and Achievements of Maria Sklodowska-Curie

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The exhibition "Life and Achievements of Maria Sklodowska-Curie” will be held at CERN (Pas Perdus Corridor, 1st floor, building 61) from the 8 to 24 March.   It is organised under the auspices of the Ambassador R. Henczel, Permanent Representative of the Republic of Poland to the UN Office at Geneva to celebrate the 100th anniversary of the Nobel Prize in Chemistry given to Maria Sklodowska-Curie. The exhibition is also one of the events celebrating the 20th anniversary of Poland joining CERN as a Member State. Maria Sklodowska-Curie, Nobel Prize winner both in physics and chemistry, is one of the greatest scientists of Polish origin. The exhibition, consisting of 20 posters, presents her not only as a brilliant scientist, but also an exceptional woman of great heart, character and organizational talents, sensitive to contemporary problems. The authors are Mrs M. Sobieszczak-Marciniak, the director of the Maria Sklodowska-Curie Museum in Warsaw and Mrs H. Krajewska, the direct...

  8. Evaluation of radiation doses delivered in different chest CT protocols

    International Nuclear Information System (INIS)

    Gorycki, Tomasz; Lasek, Iwona; Kamiński, Kamil; Studniarek, Michał

    2014-01-01

    There are differences in the reference diagnostic levels for the computed tomography (CT) of the chest as cited in different literature sources. The doses are expressed either in weighted CT dose index (CTDI VOL ) used to express the dose per slice, dose-length product (DLP), and effective dose (E). The purpose of this study was to assess the radiation dose used in Low Dose Computer Tomography (LDCT) of the chest in comparison with routine chest CT examinations as well as to compare doses delivered in low dose chest CT with chest X-ray doses. CTDI VOL and DLP doses were taken to analysis from routine CT chest examinations (64 MDCT TK LIGHT SPEED GE Medical System) performed in 202 adult patients with FBP reconstruction: 51 low dose, 106 helical, 20 angio CT, and 25 high resolution CT protocols, as well as 19 helical protocols with iterative ASIR reconstruction. The analysis of chest X-ray doses was made on the basis of reports from 44 examinations. Mean values of CTDI VOL and DLP were, respectively: 2.1 mGy and 85.1 mGy·cm, for low dose, 9.7 mGy and 392.3 mGy·cm for helical, 18.2 mGy and 813.9 mGy·cm for angio CT, 2.3 mGy and 64.4 mGy·cm for high resolution CT, 8.9 mGy. and 317.6 mGy·cm for helical ASIR protocols. Significantly lower CTDI VOL and DLP values were observed for low dose and high resolution CT versus the remaining CT protocols; doses delivered in CT ASIR protocols were also lower (80–81%). The ratio between medial doses in low dose CT and chest X-ray was 11.56. Radiation dose in extended chest LDCT with parameters allowing for identification of mediastinal structures and adrenal glands is still much lower than that in standard CT protocols. Effective doses predicted for LDCT may exceed those used in chest X-ray examinations by a factor of 4 to 12, depending on LDCT scan parameters. Our results, as well as results from other authors, suggest a possibility of reducing the dose by means of iterative reconstruction. Efforts towards further dose

  9. Controls on sublithospheric small-scale convection on Curie depths

    Science.gov (United States)

    Likerman, Jeremias; Zlotnik, Sergio; Chun-Feng, Li

    2017-04-01

    As the ocean lithosphere cools and thickens, its bottom layer goes unstable leading to sub-lithospheric small-scale convection (SSC). Since SSC was originally proposed, there have been considerable efforts regarding the understanding of the physics that rules the thermal instabilities of the SSC (e.g. Dumoulin et al, 1999; Solomatov and Moresi, 2000). Over the last several years, it is understood that the interaction between the plate movement and the SSC tends to form longitudinal (LRs or also called 'Richter rolls') and transverse rolls (TRs), of which the axis is parallel and perpendicular to the plate motion, respectively. The geometry of these rolls have been been recently inferred by Li et al (2013) using Curie depths from the North Atlantic as proxies for plates temperatures. They showed that Curie depths have a large oscillating and heterogeneous patterns that could be related to SSC. In the North Atlantic transverse rolls seem predominant. In this work we analyze, by means of 3D dynamical numerical simulations, the influence of SSC on the Curie depths patterns observed in the North Atlantic and Pacific plates. We investigate the behaviour of the Curie isotherms trying to determine if SSC is able to reproduce the observed data, and the influence of several poorly constrained rheological parameters. Our numerical simulations show that: a) using realistic laboratory-constrained rheologies and temperature it is possible to modify temperatures as low as those at Curie depths; b) transverse rolls are generated as well as longitudinal rolls on those isotherms; c) the spreading rate is a first order control on the developing of transverse rolls. References Dumoulin, C., Doin, M. P., & Fleitout, L. (1999). Heat transport in stagnant lid convection with temperature-and pressure-dependent Newtonian or non-Newtonian rheology. Journal of Geophysical Research: Solid Earth, 104(B6), 12759-12777. Li, C. F., Wang, J., Lin, J., & Wang, T. (2013). Thermal evolution of the

  10. Evaluation of effective dose equivalent from environmental gamma rays

    International Nuclear Information System (INIS)

    Saito, K.; Tsutsumi, M.; Moriuchi, S.; Petoussi, N.; Zankl, M.; Veit, R.; Jacob, P.; Drexler, G.

    1991-01-01

    Organ doses and effective dose equivalents for environmental gamma rays were calculated using human phantoms and Monte Carlo methods accounting rigorously the environmental gamma ray fields. It was suggested that body weight is the dominant factor to determine organ doses. The weight function expressing organ doses was introduced. Using this function, the variation in organ doses due to several physical factors were investigated. A detector having gamma-ray response similar to that of human bodies has been developed using a NaI(Tl) scintillator. (author)

  11. Evaluation of 1cm dose equivalent rate using a NaI(Tl) scintilation spectrometer

    International Nuclear Information System (INIS)

    Matsuda, Hideharu

    1990-01-01

    A method for evaluating 1 cm dose equivalent rates from a pulse height distribution obtained by a 76.2mmφ spherical NaI(Tl) scintillation spectrometer was described. Weak leakage radiation from nuclear facilities were also measured and dose equivalent conversion factor and effective energy of leakage radiation were evaluated from 1 cm dose equivalent rate and exposure rate. (author)

  12. Evaluating adherence to ocular hypotensives using the Travatan dosing aid

    Directory of Open Access Journals (Sweden)

    O'Dell L

    2012-01-01

    Full Text Available Leslie O'Dell1, Amy L Hennessy2,3, Alan L Robin2–41May Eye Care Center, Hanover, PA, USA; 2Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; 3Glaucoma Specialists, Baltimore, MD, USA; 4Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USAPurpose: The Travatan™ Dosing Aid (TDA is the first commercially available device designed to aid in patients' adherence to their glaucoma therapies and to record patients' eyedrop administration, so that doctors can better assess adherence. No prior studies have objectively evaluated adherence to glaucoma medications and its relationship to the severity of glaucoma or the use of multiple systemic medications.Methods: We enrolled 100 consecutive subjects from a private glaucoma practice, all currently using topical travoprost 0.004%. Each subject was issued a TDA to record the time and date of each drop instilled. Informed consents were signed and the subjects were aware that their medication use was being monitored. Patients returned for follow-up 30–60 days after their initial exam.Results: 89 subjects completed the study: 44 were male, with a mean age of 67 years, and 69.7% were Caucasian. Overall, patient adherence was 74.8% (range 22%–100% improving to 85.4% on the day prior to follow-up. The mean number of missed doses per month was 6.24 ± 5.9. Only 7.9% of the study population never missed a dose and 23.6% ± 4.3% missed more than ten drops per month. No marked association was observed between the severity of glaucoma, race, or the number of systemic medications and adherence. A marked improvement in adherence was noted in patients using travoprost 0.004% as monocular therapy rather than binocular therapy, 84.0% ± 17.1% vs 67.4% ± 23.5% (P < 0.005.Conclusion: Patient adherence to glaucoma medical therapy is a major barrier in the management and treatment of glaucoma patients given the chronic nature and asymptomatic course of the disease. Until recently

  13. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Cintya Carolina Barbosa

    2006-04-15

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  14. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Cintya Carolina Barbosa

    2006-04-15

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  15. Organ doses in interventional radiology procedures: Evaluation of software

    International Nuclear Information System (INIS)

    Tort, I.; Ruiz-Cruces, R.; Perez-Martinez, M.; Carrera, F.; Ojeda, C.; Diez de los Rios, A.

    2001-01-01

    Interventional Radiology (IR) procedures require large fluoroscopy times and important number of radiological images, so the levels of radiation to patient are high, which leads us to calculate the organ doses. The objective of this work is to estimate and make a comparison of the results given by the different software that we have to do the calculation of organ doses in complex procedures of IR. To do this, 28 patients have been selected, distributed in the 3 procedures with highest doses. The determination of organ doses and effective doses has been made using the projections utilized and different software based on Monte Carlo Methods: Eff-dose, PCXMC and Diasoft. We have obtained very high dispersion in the average organ dose between the 3 programs. In many cases, it is higher than 25% and in some particular cases, it is greater than 100%. Dispersion obtained in effective doses is not so high, being under 20% in all cases. This shows that a better solution is needed to solve the problem of the organ doses calculation; a more accurate method is necessary that brings us to a trustworthy approach to reality, and, at the moment, that we do not dispose of it. (author)

  16. Evaluation of the Occupational Doses of Interventional Radiologists

    International Nuclear Information System (INIS)

    Kuipers, Gerritjan; Velders, Xandra L.; Winter, Robbert J. de; Reekers, Jim A.; Piek, Jan J.

    2008-01-01

    The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection (ICRP) recommends the use of a single dosimeter under the protective apron. To determine the exposure more accurately an additional dosimeter is recommended above the protective apron. The exposure of eight radiologists was monitored with two personal dosimeters during 3 consecutive years. To measure the doses uniformly the two dosimeters were worn in a special holder attached to the lead apron. The two personal dosimeters were replaced every 4 weeks on the same day. The doses above and under the protective aprons of seven radiologists did not differ significantly. A significant lower dose above and under the protective apron was measured for one of the radiologists. During a 4-week period the average dose measured above the lead apron was 3.44 mSv (median, 3.05 mSv), while that under the 0.25-mm lead apron was 0.12 mSv (median, 0.1 mSv). The coefficients of the regression line result in the equation Y = 0.036X - 0.004, with Y as the dose under the lead apron and X as the dose above the lead apron. The statistical analysis of the data established a linear relation between the doses above and those under the lead apron (R 2 = 0.59). Before the special holder was introduced it was not possible to derive a relation between the doses above and those under the lead apron, as the doses were measured at varying places above and under the lead apron. There is no evidence that the effective dose can be estimated more accurately when an additional dosimeter is used. The present study revealed a threshold before doses under the lead apron were measured. Due to the threshold it can be concluded that the doses under the lead apron will not be underestimated easily when doses above the

  17. Motor power calculation for driving conveyor chain in gamma irradiator BATAN 2x250 k curie

    International Nuclear Information System (INIS)

    Ari Satmoko; Syamsurrijal Ramdja; Sutomo Budihardjo

    2010-01-01

    Recently, an Irradiator BATAN 2X250 k Curie for agricultural product is under design. The installation is provided by the gamma source about 2x250 k Curie. Agricultural products are carried into carriers and these carriers are hanged on the conveyor chain. The chain moves into a radiation chamber following the trajectoire. The chain is drived by motor. For this reason, the calculation is performed to determine the motor power. After resolving the force equilibrium equation, the force and power of the motor needed to drive the chain are obtained. Numerical method by using V Basic language is used to resolve the equation. The calculation result shows the correlation between friction coefficient and motor power. From the evaluation, it is decided that the friction coefficient should be less than 0,015. By this friction, the motor power is about 3. 13 k Watt. From the evaluation, it is also obtained that the radius of the curve trajectory shall not be too small. Combination between high friction and small curve radius could lead to the locked condition in which high power motor are not be able to move the conveyor chain). (author)

  18. Analytical evaluation of dose measurement of critical accident at SILENE (Contract research)

    CERN Document Server

    Nakamura, T; Tonoike, K

    2003-01-01

    Institute for Radioprotection and Nuclear Safety (IRSN) and the OECD Nuclear Energy Agency (NEA) jointly organized SILENE Accident Dosimetry Intercomparison Exercise to intercompare the dose measurement systems of participating countries. Each participating country carried out dose measurements in the same irradiation field, and the measurement results were mutually compared. The participated in the exercise to measure the doses of gamma rays and neutron from SILENE by using thermoluminescence dosimeters (TLD's) and an alanine dosimeter. In this examination, the derived evaluation formulae for obtaining a tissue-absorbed dose from measured value (ambient dose equivalent) of TLD for neutron. We reported the tissue-absorbed dose computed using this evaluation formula to OECD/NEA. TLD's for neutron were irradiated in the TRACY facility to verify the evaluation formulae. The results of TLD's were compared with the calculations of MCNP and measurements with alanine dose meter. We found that the ratio of the dose b...

  19. Dose evaluation of TPS according to treatment sites in IMRT

    International Nuclear Information System (INIS)

    Kim, Jin Man; Kim, Jong Sik; Hong, Chae Seon; Park, Ju Young; Park, Su Yeon; Ju, Sang Gyu

    2013-01-01

    This study executed therapy plans on prostate cancer (homogeneous density area) and lung cancer (non-homogeneous density area) using radiation treatment planning systems such as Pinnacle 3 (version 9.2, Philips Medical Systems, USA) and Eclipse (version 10.0, Varian Medical Systems, USA) in order to quantify the difference between dose calculation according to density in IMRT. The subjects were prostate cancer patients (n=5) and lung cancer patients (n=5) who had therapies in our hospital. Identical constraints and optimization process according to the Protocol were administered on the subjects. For the therapy plan of prostate cancer patients, 10 MV and 7Beam were used and 2.5 Gy was prescribed in 28 fx to make 70 Gy in total. For lung cancer patients, 6 MV and 6Beam were used and 2 Gy was prescribed in 33 fx to make 66 Gy in total. Through two therapy planning systems, maximum dose, average dose, and minimum dose of OAR (Organ at Risk) of CTV, PTV and around tumor were investigated. In prostate cancer, both therapy planning systems showed within 2% change of dose of CTV and PTV and normal organs (Bladder, Both femur and Rectum out) near the tumor satisfied the dose constraints. In lung cancer, CTV and PTV showed less than 2% changes in dose and normal organs (Esophagus, Spinal cord and Both lungs) satisfied dose restrictions. However, the minimum dose of Eclipse therapy plan was 1.9% higher in CTV and 3.5% higher in PTV, and in case of both lungs there was 3.0% difference at V5 Gy. Each TPS according to the density satisfied dose limits of our hospital proving the clinical accuracy. It is considered more accurate and precise therapy plan can be made if studies on treatment planning for diverse parts and the application of such TPS are made

  20. Dose-to-medium vs. dose-to-water: Dosimetric evaluation of dose reporting modes in Acuros XB for prostate, lung and breast cancer

    Directory of Open Access Journals (Sweden)

    Suresh Rana

    2014-12-01

    Full Text Available Purpose: Acuros XB (AXB dose calculation algorithm is available for external beam photon dose calculations in Eclipse treatment planning system (TPS. The AXB can report the absorbed dose in two modes: dose-to-water (Dw and dose-to-medium (Dm. The main purpose of this study was to compare the dosimetric results of the AXB_Dm with that of AXB_Dw on real patient treatment plans. Methods: Four groups of patients (prostate cancer, stereotactic body radiation therapy (SBRT lung cancer, left breast cancer, and right breast cancer were selected for this study, and each group consisted of 5 cases. The treatment plans of all cases were generated in the Eclipse TPS. For each case, treatment plans were computed using AXB_Dw and AXB_Dm for identical beam arrangements. Dosimetric evaluation was done by comparing various dosimetric parameters in the AXB_Dw plans with that of AXB_Dm plans for the corresponding patient case. Results: For the prostate cancer, the mean planning target volume (PTV dose in the AXB_Dw plans was higher by up to 1.0%, but the mean PTV dose was within ±0.3% for the SBRT lung cancer. The analysis of organs at risk (OAR results in the prostate cancer showed that AXB_Dw plans consistently produced higher values for the bladder and femoral heads but not for the rectum. In the case of SBRT lung cancer, a clear trend was seen for the heart mean dose and spinal cord maximum dose, with AXB_Dw plans producing higher values than the AXB_Dm plans. However, the difference in the lung doses between the AXB_Dm and AXB_Dw plans did not always produce a clear trend, with difference ranged from -1.4% to 2.9%. For both the left and right breast cancer, the AXB_Dm plans produced higher maximum dose to the PTV for all cases. The evaluation of the maximum dose to the skin showed higher values in the AXB_Dm plans for all 5 left breast cancer cases, whereas only 2 cases had higher maximum dose to the skin in the AXB_Dm plans for the right breast cancer

  1. Evaluation of absorbed doses during irradiation of patients

    International Nuclear Information System (INIS)

    Denisenko, O.N.; Kozlov, V.A.

    1981-01-01

    Provided is an analysis of a general scheme for the method of control over the dose field realization in the patient's body using direct dose measurements in patients. On the basis of data from literature presented are error limits in the stages of preradiation preparation and irradiation of patients, and in the stage of dose measurement for different irradiation techniques and radiation types. The authors also provide scientific data of their own. It has been concluded that the main emphasis should be placed on the improvement of topometry facilities, field calculation, patients posture and visual control methods of the radiation beam position [ru

  2. Multicentre evaluation of a novel vaginal dose reporting method in 153 cervical cancer patients

    DEFF Research Database (Denmark)

    Westerveld, Henrike; de Leeuw, Astrid; Kirchheiner, Kathrin

    2016-01-01

    Background and purpose Recently, a vaginal dose reporting method for combined EBRT and BT in cervical cancer patients was proposed. The current study was to evaluate vaginal doses with this method in a multicentre setting, wherein different applicators, dose rates and protocols were used. Materia...

  3. Evaluation of accelerated test parameters for CMOS IC total dose hardness prediction

    International Nuclear Information System (INIS)

    Sogoyan, A.V.; Nikiforov, A.Y.; Chumakov, A.I.

    1999-01-01

    The approach to accelerated test parameters evaluation is presented in order to predict CMOS IC total dose behavior in variable dose-rate environment. The technique is based on the analytical model of MOSFET parameters total dose degradation. The simple way to estimate model parameter is proposed using IC's input-output MOSFET radiation test results. (authors)

  4. Current evaluation of dose rate calculation - analytical method

    International Nuclear Information System (INIS)

    Tello, Marcos; Vilhena, Marco Tulio

    1996-01-01

    The accuracy of the dose calculations based on pencil beam formulas such as Fokker-Plank equations and Fermi equations for charged particle transport are studied and a methodology to solve the Boltzmann transport equation is suggested

  5. Dose rate evaluation after accident in a PWR

    International Nuclear Information System (INIS)

    Cladel, C.; Duchemin, B.; Le Dieu de Ville, A.; Nimal, B.; Nimal, J.C.; Evrard, J.M.

    1983-05-01

    A calculation scheme for the gamma radiation dose rate after accident in a PWR is presented. These studies use a fine description of the geometry and of the fission product inventory. Some results are given and some improvements are planned

  6. Evaluation of occupational radiation dose of extremities on hysterosalpingography

    International Nuclear Information System (INIS)

    Filipov, D.; Kotowski, S.T.A.

    2017-01-01

    In the Hysterosalpingography (HSG) exam there is always a professional present with their hands very close to the radiation field. Based on CNEN, individuals occupationally exposed to radiation have equivalent dose limit values for the extremities (500 mSv / year). The objective of the study was to verify the equivalent dose in the hand region of an IOE (Occupationally Exposed Individual) that performs the HSG test and to compare it with the CNEN limit and with similar studies. A humanoid phantom was used to simulate the patient and an ionization chamber, which was placed in the place commonly occupied by the professional. The equivalent hand dose result (∼ 30 mSv / year) equals 6% of the CNEN annual dose limit, but is close to most studies using fluoroscopes. Therefore, the optimization of radiological protection is necessary to reduce these results

  7. Evaluation of radiation dose received in skull radiographic examination

    International Nuclear Information System (INIS)

    Omer, Noora Elshiekh

    2014-12-01

    Diagnostic X-ray examination play an important role in the health care of the population. These examinations may involve significant irradiation of the patient and probably represent the largest mam-made source of radiation exposure for the population. This study was performed in Khartoum Teaching Hospital in period of January to June 2014. This study was performed to assess the effective dose (ED) received in skull radiographic examination and to analyze effective dose distributions among radiological department under study. The study was performed in Khartoum Teaching Hospital, covering two x-ray units and a sample of 50 patients. The following parameters were recorded: age, weight, height, body mass index (BMI) derived from weight (kg) and (height (m)) and exposure factors. The dose was measured for skull x-ray examinations. For effective dose calculation, the entrance surface dose (ESD) values were estimated from the x-ray tube output parameters for skull AP and lateral examinations. The ED values were then calculated from the obtained ESD values using IAEA calculation methods. Effective doses were calculated from energy imparted using ED conversion factors proposed were within the normal range of exposure. The mean ED values calculated were 3.03±0.08 and 4.23±0.61 for skull AP and lateral examination, respectively. Further studies are recommended with more number of patients and using more than two modalities for comparison. (Author)

  8. Evaluation of experimental animal biological state at exposure to low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Rozanov, V.A.; Rejtarova, T.Je.; Chernyikov, G.B.; Timoshevs'ka, Je.V.; Kozozojeva, O.O.

    1997-01-01

    New approaches to quantitative evaluation of ionizing radiation absorbed dose within the low-dose range (up to 400 mGy) according to the degree of the organism biological response was developed. The purpose of the stage of the work published in Communication 1 is to evaluate the shifts in the animal behaviour and cellular composition of the blood at irradiation by the dose of 100,200 and 400 mGy. Distinct dose dependence of behaviour reactions and hematological indices within the dose range of 100-400 mGy was not noted

  9. Comparative in vitro evaluation of four corticosteroid metered dose inhalers : Consistency of delivered dose and particle size distribution

    NARCIS (Netherlands)

    de Vries, Tjalling W; Rottier, Bart L; Gjaltema, Doetie; Hagedoorn, Paul; Frijlink, Henderik W; de Boer, Anne H

    2009-01-01

    Introduction: Recent developments concerning pressurized metered dose inhalers (pMDIs) with inhaled corticosteroids (ICS) are the introduction of ciclesonide and the replacement of propellants. As the results of in vivo studies depend on pMDI performance, it is necessary to evaluate pMDIs in vitro

  10. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2001-01-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  11. Design study on dose evaluation method for employees at severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio [Institute of Nuclear Safety Systems Inc., Mihama, Fukui (Japan); Kudo, Seiichi [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Nishimura, Kazuya [Computer Software Development Co., Ltd., Tokyo (Japan)

    2001-09-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  12. Aspectos históricos da visita de Marie Sklodowska Curie a Belo Horizonte

    Directory of Open Access Journals (Sweden)

    Cássius Klay Nascimento

    2011-01-01

    Full Text Available In the year 2011 it is celebrated the Marie Sklodowska Curie Nobel Prize centenary and the International Year of Chemistry. However, it is not generally known that Marie Sklodowska Curie, one of the greatest scientists of all time, visited Belo Horizonte, state of Minas Gerais, Brazil. She arrived by train at Belo Horizonte city on 16 August 1926, coming from Rio de Janeiro and accompanied by her daughter Irène Joliot-Curie. The scientists visited the Institute of Radium of Belo Horizonte. The approach in this work emphasizes the presence of Marie Sklodowska Curie in Belo Horizonte, exploring the admiration and respect that people had for her.

  13. Treatment plan evaluation using dose-volume histogram (DVH) and spatial dose-volume histogram (zDVH)

    International Nuclear Information System (INIS)

    Cheng, C.-W.; Das, Indra J.

    1999-01-01

    Objective: The dose-volume histogram (DVH) has been accepted as a tool for treatment-plan evaluation. However, DVH lacks spatial information. A new concept, the z-dependent dose-volume histogram (zDVH), is presented as a supplement to the DVH in three-dimensional (3D) treatment planning to provide the spatial variation, as well as the size and magnitude of the different dose regions within a region of interest. Materials and Methods: Three-dimensional dose calculations were carried out with various plans for three disease sites: lung, breast, and prostate. DVHs were calculated for the entire volume. A zDVH is defined as a differential dose-volume histogram with respect to a computed tomographic (CT) slice position. In this study, zDVHs were calculated for each CT slice in the treatment field. DVHs and zDVHs were compared. Results: In the irradiation of lung, DVH calculation indicated that the treatment plan satisfied the dose-volume constraint placed on the lung and zDVH of the lung revealed that a sizable fraction of the lung centered about the central axis (CAX) received a significant dose, a situation that warranted a modification of the treatment plan due to the removal of one lung. In the irradiation of breast with tangential fields, the DVH showed that about 7% of the breast volume received at least 110% of the prescribed dose (PD) and about 11% of the breast received less than 98% PD. However, the zDVHs of the breast volume in each of seven planes showed the existence of high-dose regions of 34% and 15%, respectively, of the volume in the two caudal-most planes and cold spots of about 40% in the two cephalic planes. In the treatment planning of prostate, DVHs showed that about 15% of the bladder and 40% of the rectum received 102% PD, whereas about 30% of the bladder and 50% of the rectum received the full dose. Taking into account the hollow structure of both the bladder and the rectum, the dose-surface histograms (DSH) showed larger hot-spot volume, about

  14. Evaluation of doses delivered during CT examination by different scanners for purposes of intercomparison and dose optimization

    International Nuclear Information System (INIS)

    Bashiru, Adam

    2017-07-01

    This research study was aimed at performing dosimetry intercomparison on different CT scanners in the diagnostic radiology departments of Korle-Bu Teaching Hospital (KBTH), Sweden Ghana Medical Center (SGMC) and Global Medical and Imaging Center (GMIC). Using the standard body phantom and integrated ion chamber technique volume computed tomography dose index (CTDIvol) and Dose-Length Product (DLPs) within the phantom were evaluated. The ion chamber technique was applied to two 16 slice Siemens and one Toshiba Aquilion one CT scanners. CTDIvol and DLP values for the standard body polymethyl methacrylate (PMMA) phantom were estimated and comparison made with corresponding console displayed values for accuracy and also to deduce a suitable method for optimization of patients and occupationally exposed worker doses. Effective doses were also calculated. An intra and inter institutional comparison of measured doses and console displayed doses were performed. Chest protocol at Automatic Exposure Control (AEC) was applied during the scanning of the phantom. Estimated CTDIvol values (mGy) were 17mGy, 24mGy and 13.1mGy for SGMC, GMIC and KBTH respectively. These values deviated from the console displayed values by 24.1%, 22.9% and 31.3% respectively. Similarly, estimated DLP values (mGy.cm) were 675mGy.cm,944mGy.cm and 419mGy.cm for SGMC, GMIC and KBTH respectively deviating from the console displayed values by 24.1%, 24.2% and 29% respectively. In terms of effective doses (E), the calculated E (mSv) values were 9.45mSv, 13.2mSv and 5.87mSv estimated from the DLPs from SGMC, GMIC and KBTH respectively using K, the anatomy-specific dose coefficient expressing effective dose normalized to DLP in a standard CT dosimetry phantom of 0.014 mSv mGy-1 cm-1. The estimated doses were compared to other selected international Dose Reference Levels (DRLs) and were within range. (au)

  15. SU-G-BRC-08: Evaluation of Dose Mass Histogram as a More Representative Dose Description Method Than Dose Volume Histogram in Lung Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J; Eldib, A; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Lin, M [The University of Texas Southwestern Medical Ctr, Dallas, TX (United States); Li, J [Cyber Medical Inc, Xian, Shaanxi (China); Mora, G [Universidade de Lisboa, Codex, Lisboa (Portugal)

    2016-06-15

    Purpose: Dose-volume-histogram (DVH) is widely used for plan evaluation in radiation treatment. The concept of dose-mass-histogram (DMH) is expected to provide a more representative description as it accounts for heterogeneity in tissue density. This study is intended to assess the difference between DVH and DMH for evaluating treatment planning quality. Methods: 12 lung cancer treatment plans were exported from the treatment planning system. DVHs for the planning target volume (PTV), the normal lung and other structures of interest were calculated. DMHs were calculated in a similar way as DVHs expect that the voxel density converted from the CT number was used in tallying the dose histogram bins. The equivalent uniform dose (EUD) was calculated based on voxel volume and mass, respectively. The normal tissue complication probability (NTCP) in relation to the EUD was calculated for the normal lung to provide quantitative comparison of DVHs and DMHs for evaluating the radiobiological effect. Results: Large differences were observed between DVHs and DMHs for lungs and PTVs. For PTVs with dense tumor cores, DMHs are higher than DVHs due to larger mass weighing in the high dose conformal core regions. For the normal lungs, DMHs can either be higher or lower than DVHs depending on the target location within the lung. When the target is close to the lower lung, DMHs show higher values than DVHs because the lower lung has higher density than the central portion or the upper lung. DMHs are lower than DVHs for targets in the upper lung. The calculated NTCPs showed a large range of difference between DVHs and DMHs. Conclusion: The heterogeneity of lung can be well considered using DMH for evaluating target coverage and normal lung pneumonitis. Further studies are warranted to quantify the benefits of DMH over DVH for plan quality evaluation.

  16. Evaluation of the occupational doses of interventional radiologists

    NARCIS (Netherlands)

    Kuipers, Gerritjan; Velders, Xandra L.; de Winter, Robbert J.; Reekers, Jim A.; Piek, Jan J.

    2008-01-01

    The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection

  17. 4. Evaluation of the quality of fixed dose combination anti ...

    African Journals Online (AJOL)

    Esem

    Methodology: This was a cross sectional study whose objective was to determine the quality of 3 types of fixed dose combination (FDC) anti TB drugs namely 4FDC, 3FDC and 2FDC tablets available in Lusaka District by assessing the presence of active ingredients and the percentage content of these active ingredients ...

  18. Technical background for shallow (skin) dose equivalent evaluations

    International Nuclear Information System (INIS)

    Ashley, J.C.; Turner, J.E.; Crawford, O.H.; Hamm, R.N.; Reaves, K.L.; McMahan, K.L.

    1991-01-01

    Department of Energy Order 5480.11 describes procedures for radiation protection for occupational workers. The revisions dealing with non-uniform exposure to the skin are the subject of this report. We describe measurements and analysis required to assess shallow (skin) dose equivalent from skin contamination. 6 refs., 4 tabs

  19. Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    2007-01-01

    Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

  20. Six problems with the 6-day Curie and a solution

    International Nuclear Information System (INIS)

    Adi Paterson; Michael Druce; Elizabeth Killen

    2015-01-01

    In this review the major shortfalls of the unit of sale for the Mo-99 supply chain - the 6-day Curie - are identified and discussed. These include its status as an inconsistent, out-dated, non-SI unit, and its use causing propagation of inefficient logistics within the Mo-99 supply chain. An alternative Mo-99 unit of sale is proposed: Becquerels time-stamped at the Port of Despatch. Adoption of the new unit is proposed as a catalyst in the move away from the current economically unsustainable, Mo-99 supply chain in favour of simplicity, self-regulation, transparency, efficiency, and full-cost recovery in line with High-Level Group for the Security of Supply of Medical Radioisotopes recommendations. (author)

  1. Curie temperature rising by fluorination for Sm2Fe17

    Directory of Open Access Journals (Sweden)

    Matahiro Komuro

    2013-02-01

    Full Text Available Fluorine atoms can be introduced to Sm2Fe17 using XeF2 below 423 K. The resulting fluorinated Sm2Fe17 powders have ferromagnetic phases containing Sm2Fe17FY1(0Curie temperature from 403 K for Sm2Fe17 to 675 K. This increase can be explained by the magneto-volume effect.

  2. Joliot-Curie School of Nuclear Physics, 1997

    International Nuclear Information System (INIS)

    Abgrall, Y.

    1998-01-01

    This document contains the lectures of the Joliot-Curie International School of Nuclear Physics held at Maubuisson, France on 8-13 September 1997. The following lectures of nuclear interest were given: The N-body problem (relativistic and non-relativistic approaches); The shell model (towards a unified of the nuclear structure); Pairing correlations in extreme conditions; Collective excitations in nuclei; Exotic nuclei (production, properties and specificities); Exotic nuclei (halos); Super and hyper deformation (from discrete to continuum, from EUROGAM to EUROBALL); and The spectroscopy of fission fragments. Important new facts are reported and discussed theoretically, concerning the nuclei in high excitation and high states and of the nuclei far off stability. Important technical achievements are reported among which the production of radioactive beams, sophisticated multi-detectors as well as significant advances in the nuclear theoretical methods. The double goal of training of young researchers and of permanent formation and information of the older ones seems to have been reached

  3. Malleable Curie Temperatures of Natural Titanomagnetites: Occurrences, Modes, and Mechanisms

    Science.gov (United States)

    Jackson, Mike; Bowles, Julie

    2018-02-01

    Intermediate-composition titanomagnetites have Curie temperatures (Tc) that depend not only on composition but also on thermal history, with increases of 100°C or more in Tc produced by moderate-temperature (300-400°C) annealing in the laboratory or in slow natural cooling and comparable decreases produced by more rapid cooling ("quenching") from higher temperatures. New samples spanning a range of titanomagnetite compositions exhibit reversible changes in Tc comparable to those previously documented for pyroclastic samples from Mt. St. Helens and Novarupta. Additional high- and low-temperature measurements help to shed light on the nanoscale mechanisms responsible for the observed changes in Tc. High-T hysteresis measurements exhibit a peak in high-field slope khf(T) at the Curie temperature, and the peak magnitude decreases as Tc increases with annealing. Sharp changes in low-T magnetic behavior are also strongly affected by prior annealing or quenching, suggesting that these treatments affect the intrasite cation distributions. We have examined the effects of oxidation state and nonstoichiometry on the magnitude of Tc changes produced by quenching/annealing in different atmospheres. Treatments in air generally cause large changes (ΔTc > 100°). In an inert atmosphere, the changes are similar in many samples but strongly diminished in others. When the samples are embedded in a reducing material, ΔTc becomes insignificant. These results strongly suggest that cation vacancies play an essential role in the cation rearrangements responsible for the observed changes in Tc. Some form of octahedral-site chemical clustering or short-range ordering appears to be the best way to explain the large observed changes in Tc.

  4. Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

    1980-09-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

  5. Technology Development for Radiation Dose Measurement and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Hwan; Chang, S. Y.; Lee, T. Y. (and others)

    2007-06-15

    The correction factors essential for the operation of In-Vivo counting system were produced and implemented into a field operation for the improvement of accuracy in measurement of the radioactivity inside a human body. The BiDAS2007 code which calculate an internal dose was developed by upgrading the former code prepared in the previous stage of this project. The method of using the multibioassy data, the maximum likelihood function and the Bayesian statistics were established to an internal dose based on the measurement data of radioactivity, intakes and retention of radioactivity in a human body and it can improve the accuracy in estimation of the intakes of radioactivity and the committed effective dose equivalent. In order to solve the problem of low detection efficiency of the conventional Bonner Sphere (BS) to a high energy neutron, the extended BS's were manufactured and the technique for neutron field spectrometry was established. The fast neutron and gamma spectrometry system with a BC501A scintillation detector was also prepared. Several neutron fluence spectra at several nuclear facilities were measured and collected by using the extended BS. The spectrum weighted responses of some neutron monitoring instruments were also derived by using these spectra and the detector response functions. A high efficient TL material for the neutron personal dosimeter was developed. It solved the main problem of low thermal stability and high residual dose of the commercial TLDs and has the sensitivity to neutron and to gamma radiation with 40 and 10 times higher respectively than them.

  6. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    Energy Technology Data Exchange (ETDEWEB)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M., E-mail: diilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UFTPR), Curitiba, PR (Brazil); Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano, E-mail: ledesmajorgealberto@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

    2014-07-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  7. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    International Nuclear Information System (INIS)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M.; Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano

    2014-01-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  8. Identification and dose evaluation of irradiated beef containing bones

    International Nuclear Information System (INIS)

    Mangiacotti, M.; Alberti, A.; Fuochi, P.G.; Chiesa, L.M.

    2011-01-01

    Complete text of publication follows. Food irradiation is a well-established technique to extend the food shelf life and to reduce the food-related health hazards caused by pathogenic micro-organisms. At present, radiation treatment is permitted for various categories of food and food ingredients in many countries. At the European level, irradiation of food is regulated by the European Directives 1999/2/EC and 1999/3/EC. Community legislation states that any food or food ingredients, authorised in the European Union, must be labelled with the word 'irradiated' and that every year each Member State has to carry out checks at the product marketing stage to enforce correct labelling. The present work aimed at identifying irradiated beef meat by using a reliable and sensitive detection of DNA comets as screening biological method and performing an Electron Spin Resonance (ESR) spectrometry as confirmatory qualitative standard. The influence of storage conditions and time after irradiation on DNA degradation was also investigated. Furthermore the application of ESR technique as a quantitative method was successfully applied to beef bones, using the approach of calibration curve. Results, although the limited statistics, proved for reliability of the dose reconstruction method and blind tests were carried out resulting in very satisfactory difference between actual treatment dose and reconstructed dose.

  9. Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

    International Nuclear Information System (INIS)

    Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young

    2016-01-01

    The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety

  10. Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young [Dept. of Nuclear Engineering, Kyung Hee University, Yongin (Korea, Republic of)

    2016-11-15

    The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety.

  11. Realization of 3D evaluation algorithm in dose-guided radiotherapy

    International Nuclear Information System (INIS)

    Wang Yu; Li Gui; Wang Dong; Wu Yican; FDS Team

    2012-01-01

    3D evaluation algorithm instead of 2D evaluation method of clinical dose verification is highly needed for dose evaluation in Dose-guided Radiotherapy. 3D evaluation algorithm of three evaluation methods, including Dose Difference, Distance-To-Agreement and 7 Analysis, was realized by the tool of Visual C++ according to the formula. Two plans were designed to test the algorithm, plan 1 was radiation on equivalent water using square field for the verification of the algorithm's correctness; plan 2 was radiation on the emulation head phantom using conformal field for the verification of the algorithm's practicality. For plan 1, the dose difference, in the tolerance range has a pass rate of 100%, the Distance-To-Agreement and 7 analysis was of a pass rate of 100% in the tolerance range, and a pass rate of 99±1% at the boundary of range. For plan 2, the pass rate of algorithm were 88.35%, 100%, 95.07% for the three evaluation methods, respectively. It can be concluded that the 3D evaluation algorithm is feasible and could be used to evaluate 3D dose distributions in Dose-guided Radiotherapy. (authors)

  12. Evaluating correlation between geometrical relationship and dose difference caused by respiratory motion using statistical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Seok; Kim, Dong Su; Kim, Tae Ho; Kim, Kyeong Hyeon; Yoon, Do Kun; Suh, Tae Suk [The Catholic University of Korea, Seoul (Korea, Republic of); Kang, Seong Hee [Seoul National University Hospital, Seoul (Korea, Republic of); Cho, Min Seok [Asan Medical Center, Seoul (Korea, Republic of); Noh, Yu Yoon [Eulji University Hospital, Daejeon (Korea, Republic of)

    2017-04-15

    Three-dimensional dose (3D dose) can consider coverage of moving target, however it is difficult to provide dosimetric effect which occurs by respiratory motions. Four-dimensional dose (4D dose) which uses deformable image registration (DIR) algorithm from four-dimensional computed tomography (4DCT) images can consider dosimetric effect by respiratory motions. The dose difference between 3D dose and 4D dose can be varied according to the geometrical relationship between a planning target volume (PTV) and an organ at risk (OAR). The purpose of this study is to evaluate the correlation between the overlap volume histogram (OVH), which quantitatively shows the geometrical relationship between the PTV and OAR, and the dose differences. In conclusion, no significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value. No significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value.

  13. A global reference model of Curie-point depths based on EMAG2

    Science.gov (United States)

    Li, Chun-Feng; Lu, Yu; Wang, Jian

    2017-03-01

    In this paper, we use a robust inversion algorithm, which we have tested in many regional studies, to obtain the first global model of Curie-point depth (GCDM) from magnetic anomaly inversion based on fractal magnetization. Statistically, the oceanic Curie depth mean is smaller than the continental one, but continental Curie depths are almost bimodal, showing shallow Curie points in some old cratons. Oceanic Curie depths show modifications by hydrothermal circulations in young oceanic lithosphere and thermal perturbations in old oceanic lithosphere. Oceanic Curie depths also show strong dependence on the spreading rate along active spreading centers. Curie depths and heat flow are correlated, following optimal theoretical curves of average thermal conductivities K = ~2.0 W(m°C)-1 for the ocean and K = ~2.5 W(m°C)-1 for the continent. The calculated heat flow from Curie depths and large-interval gridding of measured heat flow all indicate that the global heat flow average is about 70.0 mW/m2, leading to a global heat loss ranging from ~34.6 to 36.6 TW.

  14. Special Workshop of Marie Curie Fellows on Research and Training in Physics and Technology

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    Photo 0210006_07a: Prof. L. Maiani, Director General of CERN. Addressing the Marie Curie Worshop held at CERN 3-4 October 2002. Title of this talk:"Function of Large-scale Facilities and Centres of Excellence". Photo 0210006_14a: Prof. L. Maiani, Director General of CERN. Addressing the Marie Curie Worshop held at CERN 3-4 October 2002. Title of this talk:"Function of Large-scale Facilities and Centres of Excellence". Photo 0210006_22: Dr. David Plane (CERN) introducing Dr. Theodore Papazoglou from the European Commission. Addressing the Marie Curie Worshop held at CERN 3-4 October 2002. Title of this talk:"Marie Curie Fellowships in the 6th Framework Programme". Photo 0210006_28a: Dr. Nora Brambilla, Vice-President of Marie Curie Fellow Association, INFN and Dept. of Physics, University of Milan. Addressing the Marie-Curie Worshop held at CERN 3-4 October 2002. Title of this talk:"Marie Curie Fellows Association". Photo 0210006_29a: Dr. Nora Brambilla, Vice-President of Marie Curie Fellow Association, INFN a...

  15. Dose and risk evaluation in digital mammography using computer modeling

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de; Silva, Humberto de Oliveira; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga

    2010-01-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  16. Dose and risk evaluation in digital mammography using computer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de, E-mail: scorrea@nuclear.ufrj.b, E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CCMAT/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Humberto de Oliveira, E-mail: hbetorj@gmail.co [Universidade Federal do Rio de Janeiro IF/UFRJ, RJ (Brazil). Inst. de Fisica; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b, E-mail: smagalhaes@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2010-07-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  17. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Froehlich, Georgina; Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor

    2010-01-01

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D min ) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D r ) and urethra (D u ), dose to volume of 2 cm 3 of the rectum (D 2ccm ), and 0.1 cm 3 and 1% of the urethra (D 0.1ccm and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V p ) was 27.1 cm 3 . The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D min was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D 2ccm = 49% for the rectum, D 0.1ccm = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D r , D 2ccm ) = 0.69, R(D u , D 0.1ccm ) = 0.64, R(D u , D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric

  18. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Georgina [Semmelweis Univ., Budapest (Hungary); Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary)

    2010-07-15

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D{sub min}) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D{sub r}) and urethra (D{sub u}), dose to volume of 2 cm{sup 3} of the rectum (D{sub 2ccm}), and 0.1 cm{sup 3} and 1% of the urethra (D{sub 0.1ccm} and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V{sub p}) was 27.1 cm{sup 3}. The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D{sub min} was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D{sub 2ccm} = 49% for the rectum, D{sub 0.1ccm} = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D{sub r}, D{sub 2ccm}) = 0.69, R(D{sub u}, D{sub 0.1ccm}) = 0.64, R(D{sub u}, D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose

  19. Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

    Science.gov (United States)

    Fröhlich, Georgina; Agoston, Péter; Lövey, József; Somogyi, András; Fodor, János; Polgár, Csaba; Major, Tibor

    2010-07-01

    To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

  20. Evaluation of a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Imae, Toshikazu; Takenaka, Shigeharu; Saotome, Naoya

    2016-01-01

    The purpose of this study was to evaluate a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy (SBRT) using volumetric modulated arc therapy (VMAT). VMAT is capable of acquiring respiratory signals derived from projection images and machine parameters based on machine logs during VMAT delivery. Dose distributions were reconstructed from the respiratory signals and machine parameters in the condition where respiratory signals were without division, divided into 4 and 10 phases. The dose distribution of each respiratory phase was calculated on the planned four-dimensional CT (4DCT). Summation of the dose distributions was carried out using deformable image registration (DIR), and cumulative dose distributions were compared with those of the corresponding plans. Without division, dose differences between cumulative distribution and plan were not significant. In the condition Where respiratory signals were divided, dose differences were observed over dose in cranial region and under dose in caudal region of planning target volume (PTV). Differences between 4 and 10 phases were not significant. The present method Was feasible for evaluating cumulative dose distribution in VMAT-SBRT using 4DCT and DIR. (author)

  1. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2002-01-01

    If a severe accident occurs in a pressurized water reactor plant, it is required to estimate dose values of operators engaged in emergency such as accident management, repair of failed parts. However, it might be difficult to measure radiation dose rate during the progress of an accident, because radiation monitors are not always installed in areas where the emergency activities are required. In this study, we analyzed the transport of radioactive materials in case of a severe accident, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system from this design study, and then evaluated its availability. As a result, we obtained the following: (1) A new dose evaluation method was established to predict the radiation dose rate at any point in the plant during a severe accident scenario. (2) This evaluation of total dose including access route and time for emergency activities is useful for estimating radiation dose limit for these employee actions. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  2. Antipsychotic treatment dosing profile in patients with schizophrenia evaluated with electronic monitoring (MEMS®).

    Science.gov (United States)

    Acosta, Francisco J; Ramallo-Fariña, Yolanda; Bosch, Esperanza; Mayans, Teresa; Rodríguez, Carlos J; Caravaca, Ana

    2013-05-01

    Although the Medication Event Monitoring System (MEMS®) device offers accurate information on treatment dosing profile, such profile has never been studied in patients with schizophrenia. Enhancing our knowledge on this issue would help in developing intervention strategies to improve adherence to antipsychotic treatment in these patients. 74 outpatients with schizophrenia were monitored with the MEMS device for a 3-month period, for evaluation of antipsychotic treatment dosing profile, possible influence of medication schedule-related variables, adherence to treatment--considering dose intake within prescribed timeframes--and possible Hawthorne's effect of using the MEMS device. Dose-omission gaps occurred in 18.7% of monitoring days, most frequently during weekends, almost significantly. Almost one-third of prescribed doses were taken out of prescribed time. Neither the prescribed number of daily doses nor the indicated time of the day for dose intake (breakfast, dinner), were associated with correct antipsychotic dosing. Excess-dose was rare in general, and more frequent out of prescribed dose timeframe. No Hawthorne's effect was found for the MEMS device. Adherence reached only 35% according to a definition that included dose intake within prescribed timeframes. Antipsychotic treatment dosing was considerably irregular among patients with schizophrenia. Strategies to reduce dose-omission gaps and increase dosing within prescribed timeframes seem to be necessary. Gaining knowledge on precise oral antipsychotic dosing profiles or the influence of schedule-related variables may be useful to design strategies towards enhancing adherence. There appears to be no Hawthorne's effect associated with the use of MEMS devices in outpatients with schizophrenia. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. X-ray absorbed doses evaluation on patients under radiological studies

    International Nuclear Information System (INIS)

    Medeiros, Regina Bitelli; Daros, Kellen A.C.

    1996-01-01

    The skin absorbed doses were evaluated on patient submitted to the following x-ray exams : chest, facial sinus, lumbar spine. Thermoluminescent dosimetry was used and a variety of irradiation techniques performed. The results shown considerable differences on the absorbed dose for the various alternative technical conditions

  4. Analytical evaluation of dose measurement of critical accident at SILENE (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Takemi; Tonoike, Kotaro; Miyoshi, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Institute for Radioprotection and Nuclear Safety (IRSN) and the OECD Nuclear Energy Agency (NEA) jointly organized SILENE Accident Dosimetry Intercomparison Exercise to intercompare the dose measurement systems of participating countries. Each participating country carried out dose measurements in the same irradiation field, and the measurement results were mutually compared. The authors participated in the exercise to measure the doses of gamma rays and neutron from SILENE by using thermoluminescence dosimeters (TLD's) and an alanine dosimeter. In this examination, the authors derived evaluation formulae for obtaining a tissue-absorbed dose from measured value (ambient dose equivalent) of TLD for neutron. We reported the tissue-absorbed dose computed using this evaluation formula to OECD/NEA. TLD's for neutron were irradiated in the TRACY facility to verify the evaluation formulae. The results of TLD's were compared with the calculations of MCNP and measurements with alanine dose meter. We found that the ratio of the dose by the evaluation formula to the measured value by the alanine dosimeter was 0.94 and the formula agreed within 6%. From examination of this TRACY, we can conclude that the value reported to OECD/NEA has equivalent accuracy. (author)

  5. Video dosimetry: evaluation of X-radiation dose by video fluoroscopic image

    International Nuclear Information System (INIS)

    Nova, Joao Luiz Leocadio da; Lopes, Ricardo Tadeu

    1996-01-01

    A new methodology to evaluate the entrance surface dose on patients under radiodiagnosis is presented. A phantom is used in video fluoroscopic procedures in on line video signal system. The images are obtained from a Siemens Polymat 50 and are digitalized. The results show that the entrance surface dose can be obtained in real time from video imaging

  6. Mathematical phantoms for evaluation of age-specific internal dose

    International Nuclear Information System (INIS)

    Cristy, M.

    1980-01-01

    A series of mathematical phantoms representing children has been developed for use with photon transport codes. These phantoms, patterned after the Fisher-Snyder adult phantom, consist of simple mathematical expressions for the boundaries of the major organs and body sections. The location and shape of the organs are consistent with drawings depicting developmental anatomy, with the organ volumes assigned such that the masses at the various ages conform closely with the data presented in Reference Man. The explicit mathematical expressions for the various ages overcome the potential misrepresentation of organ sizes that occurred in phantoms derived from simple mathematical transformations of the adult phantom. Female breast tissue has been added to the phantoms, including the adult, now allowing assessment of doses to this organ

  7. Radiation exposure and dose evaluation in intraoral dental radiology

    International Nuclear Information System (INIS)

    Poppe, B.; Looe, H. K.; Pfaffenberger, A.; Eenboom, F.; Chofor, N.; Sering, M.; Ruehmann, A.; Poplawski, A.; Willborn, K.

    2007-01-01

    In this study, dose area product measurements have been performed to propose diagnostic reference levels (DRLs) in intraoral dental radiology. Measurements were carried out at 60 X-ray units for all types of intraoral examinations performed in clinical routine. The third quartile values calculated range from 26.2 to 87.0 mGy cm 2 . The results showed that there exists a large difference between the patient exposures among different dental facilities. It was also observed that dentists working with faster film type or higher tube voltage are not always associated with lower exposure. The study demonstrated the necessity to have the DRLs laid out as guidelines in dental radiology. (authors)

  8. Evaluating the Application of Tissue-Specific Dose Kernels Instead of Water Dose Kernels in Internal Dosimetry : A Monte Carlo Study

    NARCIS (Netherlands)

    Moghadam, Maryam Khazaee; Asl, Alireza Kamali; Geramifar, Parham; Zaidi, Habib

    2016-01-01

    Purpose: The aim of this work is to evaluate the application of tissue-specific dose kernels instead of water dose kernels to improve the accuracy of patient-specific dosimetry by taking tissue heterogeneities into consideration. Materials and Methods: Tissue-specific dose point kernels (DPKs) and

  9. Evaluation of glandular dose in conventional and digital mammography systems

    International Nuclear Information System (INIS)

    Coutinho, Celia Maria Campos

    2009-01-01

    A survey was conducted to estimate the average glandular dose (D g ) for patients undergoing mammography and to report the distribution of incident air kerma (K i ), patient age, compressed breast thickness and glandular tissue content. From 1183 cranio caudal mammograms clinical data were collected and doses were measured. The survey data included mammograms from six mammography equipment: two screen/film units (SFM), two computed radiography units (CR) and two full-field digital (DR). Mean value for patient age and compressed breast thickness were 57 +-12 y and 5.4 +-1.4 cm, respectively. To investigate the importance of technical characteristics of three different mammography systems and breast glandularity, K i and D g were measured for individual breast of 392 patients from the original sample with compressed breast thickness in the range of 5.5 cm to 6.5 cm using tissue-equivalent phantoms of different glandularities manufactured in this study to mimic both the attenuation and the density of breast tissues. Mean K i value was 10.0 +-3.6 mGy for SFM systems, 12.0 +-3.6 mGy for CR systems and 4.9 +-1.3 mGy for DR systems. Mean D g value was 1.4 +-0.5 mGy for S/F systems, 1.7 +-0.5 mGy for CR systems and 0.9 +-0.2 mGy for D R systems. Statistical analysis for differences in mean values of K i and D g between mammography systems showed significant effect of their technical characteristics (p i and D g , it was observed statistically significant differences between the group of patients with 0 to 50% glandularity and the group of patients with 50 to 100% glandularity. (author)

  10. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study

    International Nuclear Information System (INIS)

    Vogl, T.J.; Friebe, C.E.; Balzer, T.; Mack, M.G.; Steiner, S.; Schedel, H.; Pegios, W.; Lanksch, W.; Banzer, D.; Felix, R.

    1995-01-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [de

  11. Curie point depth from spectral analysis of aeromagnetic data for geothermal reconnaissance in Afghanistan

    Science.gov (United States)

    Saibi, H.; Aboud, E.; Gottsmann, J.

    2015-11-01

    The geologic setting of Afghanistan has the potential to contain significant mineral, petroleum and geothermal resources. However, much of the country's potential remains unknown due to limited exploration surveys. Here, we present countrywide aeromagnetic data to estimate the Curie point depth (CPD) and to evaluate the geothermal exploration potential. CPD is an isothermal surface at which magnetic minerals lose their magnetization and as such outlines an isotherm of about 580 °C. We use spectral analysis on the aeromagnetic data to estimate the CPD spatial distribution and compare our findings with known geothermal fields in the western part of Afghanistan. The results outline four regions with geothermal potential: 1) regions of shallow Curie point depths (∼16-21 km) are located in the Helmand basin. 2) regions of intermediate depths (∼21-27 km) are located in the southern Helmand basin and the Baluchistan area. 3) Regions of great depths (∼25-35 km) are located in the Farad block. 4) Regions of greatest depths (∼35-40 km) are located in the western part of the northern Afghanistan platform. The deduced thermal structure in western Afghanistan relates to the collision of the Eurasian and Indian plates, while the shallow CPDs are related to crustal thinning. This study also shows that the geothermal systems are associated with complex magmatic and tectonic association of major intrusions and fault systems. Our results imply geothermal gradients ranging from 14 °C/km to 36 °C/km and heat-flow values ranging from 36 to 90 mW/m2 for the study area.

  12. Scoping calculation for components of the cow-milk dose pathway for evaluating the dose contribution from iodine-131

    International Nuclear Information System (INIS)

    Ikenberry, T.A.; Napier, B.A.

    1992-12-01

    A series of scoping calculations have been undertaken to evaluate The absolute and relative contribution of different exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford site. This scoping calculation (Calculation 001) examined the contributions of the various exposure pathways associated with environmental transport and accumulation of iodine-131 in the pasture-cow-milk pathway. Addressed in this calculation were the contributions to thyroid dose of infants and adult from (1) the ingestion by dairy cattle of various feedstuffs (pasturage, silage, alfalfa hay, and grass hay) in four different feeding regimes; (2) ingestion of soil by dairy cattle; (3) ingestion of stared feed on which airborne iodine-131 had been deposited; and (4) inhalation of airborne iodine-131 by dairy cows

  13. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    D' Oca, Maria Cristina, E-mail: mcristina.doca@unipa.it [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Bartolotta, Antonio [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy)

    2011-09-15

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  14. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    International Nuclear Information System (INIS)

    D'Oca, Maria Cristina; Bartolotta, Antonio

    2011-01-01

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  15. Percentage depth dose evaluation in heterogeneous media using thermoluminescent dosimetry

    Science.gov (United States)

    da Rosa, L.A.R.; Campos, L.T.; Alves, V.G.L.; Batista, D.V.S.; Facure, A.

    2010-01-01

    The purpose of this study is to investigate the influence of lung heterogeneity inside a soft tissue phantom on percentage depth dose (PDD). PDD curves were obtained experimentally using LiF:Mg,Ti (TLD‐100) thermoluminescent detectors and applying Eclipse treatment planning system algorithms Batho, modified Batho (M‐Batho or BMod), equivalent TAR (E‐TAR or EQTAR), and anisotropic analytical algorithm (AAA) for a 15 MV photon beam and field sizes of 1×1,2×2,5×5, and 10×10cm2. Monte Carlo simulations were performed using the DOSRZnrc user code of EGSnrc. The experimental results agree with Monte Carlo simulations for all irradiation field sizes. Comparisons with Monte Carlo calculations show that the AAA algorithm provides the best simulations of PDD curves for all field sizes investigated. However, even this algorithm cannot accurately predict PDD values in the lung for field sizes of 1×1 and 2×2cm2. An overdosage in the lung of about 40% and 20% is calculated by the AAA algorithm close to the interface soft tissue/lung for 1×1 and 2×2cm2 field sizes, respectively. It was demonstrated that differences of 100% between Monte Carlo results and the algorithms Batho, modified Batho, and equivalent TAR responses may exist inside the lung region for the 1×1cm2 field. PACS number: 87.55.kd

  16. Dose evaluation due to electron spin resonance method

    International Nuclear Information System (INIS)

    Nakajima, Toshiyuki

    1989-01-01

    Radiation dosimeter has been developed with free radical created in sucrose. Free radical was observed with using the electron spin resonance (ESR) equipment. The ESR absorption due to free radical in sucrose appeared at the magnetic field between the third and fourth ESR ones of Mn +2 standard sample. Sucrose as radiation dosimeter can linearly measure the dose from 5 x 10 -3 Gy to 10 5 Gy. If the new model of the ESR equipment is used and ESR observation is carried out at lower temperature such as liquid nitrogen or liquid helium temperature, the sucrose ESR dosimeter will be detectable about 5 x 10 -4 Gy or less. Fading of the free radicals in the irradiated sucrose was scarcely obtained about six months after irradiation and in the irradiated sucrose stored at 55deg C and 100deg C for one hour or more also scarcely observed. It is concluded from these radiation property that sucrose is useful for the accidental or emergency dosimeter for the inhabitants. (author)

  17. Guidance document for setting an Acute Reference Dose in Dutch national pesticide evaluations

    NARCIS (Netherlands)

    Raaij MTM van; CSR

    2001-01-01

    This report describes a proposal for the procedures for setting an Acute Reference Dose (ARfD) for pesticides evaluated in the Netherlands. This deals with both evaluations on the national level (on behalf of the Dutch Board for the Authorisation of Pesticides (CTB)) and evaluations at the European

  18. Evaluation of skyshine dose due to gamma-rays from a cobalt-60 irradiation facility

    International Nuclear Information System (INIS)

    Kanazawa, Tamotsu; Okamoto, Shinichi; Ohnishi, Tokuhiro; Tsujii, Yukio

    1991-01-01

    We attempted to evaluate skyshine dose due to gamma-rays from a cobalt-60 irradiation facility. As the first step, the results of measurements and calculations were compared of the skyshine dose due to gamma-rays from the cobalt-60 source of 1.45 PBq set in the No.4 irradiation room of our laboratory. Distances of measuring points from the cobalt source were in the range from 17 m to about 100 m in the site of our office. Calculation was carried out with simplified single scattering method. The calculated values of the skyshine dose were higher than the measured values. For more precise evaluation of the skyshine dose, the following factors are to be considered; the dose rate distribution on the roof above the source and the attenuation of gamma-rays by air. (author)

  19. Effective dose evaluation for BNCT treatment in the epithermal neutron beam at THOR

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.N. [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)] [Division of Health Physics, Institute of Nuclear Energy Research, No. 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan (China); Huang, C.K. [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Tsai, W.C. [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Liu, Y.H. [Nuclear Science and Technol. Develop. Center, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Jiang, S.H., E-mail: shjiang@mx.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)] [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)

    2011-12-15

    This paper aims to evaluate the effective dose as well as equivalent doses of several organs of an adult hermaphrodite mathematical phantom according to the definition of ICRP Publication 60 for BNCT treatments of brain tumors in the epithermal neutron beam at THOR. The MCNP5 Monte Carlo code was used for the calculation of the average absorbed dose of each organ. The effective doses for a typical brain tumor treatment with a tumor treatment dose of 20 Gy-eq were evaluated to be 0.59 and 0.35 Sv for the LLAT and TOP irradiation geometries, respectively. In addition to the stochastic effect, it was found that it is also likely to produce deterministic effects, such as cataracts and depression of haematopoiesis.

  20. Evaluation of dose delivered to critical organs during pituitary radiation therapy

    International Nuclear Information System (INIS)

    Awoda, Marwa Elrashied Mohammed

    2017-12-01

    The selection of an appropriate energy in radiation therapy for tumor and the delivery adequate dose to the tumors to be treated, is very important during the radiation treatment planning. Also the dose received to critical organs surrounding the tumor has be considered. In addition, validation of treatment plan quality is important, so the purpose of this study was to evaluate the effect of teletherapy cobalt and 6MV linac energies on dose distribution for the pituitary gland tumors and dose delivered to critical organs surrounding the tumor. 10 patients with pituitary adenocarcinomas were selected. For treatment plans with three field technique, verdes and two lateral fields, were used. For the therapeutic area, five organs left and right eye lens left and right optic never and chasms and brain stem, were considered as Organ at risk (OARS). Several physical indices for for planning target volume (PTV) and the organs at risk 9 (OARS) as means dose (MD). 95%, dose (D950), 5% dose (D5) and normal tissue dose (NTID), were calculated, and the homogeneity index and conformity index were also two other evaluation parameters have been taken into account. The comparative evaluation was based on dose volume histogram ( DVH) analysis for both energies plans. After performing the treatment planning with two different energies the dose received to critical organs and dose distribution in PTV were studied. Results showed that the difference between the integral dose received to OARs with Co-60 and 6-MV linac respectively, 2.16±1.48, 1.85±1.55 for Lt eye lens. 3.01±2.52, 1.89±2.09 for Rt eye lens, 18.5±10.97, 19.43±10.65 for Lt optic nerve and chasms, 15.86±11.30, 17.44±15.73 for Rt optic nerve and chasms and 24.03±13.68, 23.77±16.64 for Brain stem case showed higher integral dose for linac than Co-60 than due to using the 6-MV energy as an open field with no beam modifiers such MLCs or shielding blocks. Eventually, it found that using of 6-MV linac provides better

  1. A methodology for the evaluation of collective doses arising from radioactive discharges to the atmosphere

    International Nuclear Information System (INIS)

    Hallam, J.; Linsley, G.S.

    1980-01-01

    The ICRP recommend the use of optimisation as a means of ensuring that the total detriment from any practice is appropriately small in relation to the benefit resulting from its introduction. The calculation of total health detriment requires the evaluation of the complete dose distribution throughout the irradiated population from all isotopes via all pathways. This paper describes methods for the evaluation of collective dose, which may be used in the assessment of detriment. The stages in the assessment of collective dose from an atmospheric release can be summarised as follows: (1) An atmospheric dispersion model is used to evaluate the spatial distribution of activity and thereby the dose to an individual from inhalation and external irradiation at any position with respect to the discharge point. (2) The UK population distribution on a 1 x 1 km grid is then used for the evaluation of collective dose from these pathways. (3) Foodchain models are used to estimate the radioactivity per unit mass in a range of different foodstuffs per unit deposition rate or surface deposit. (4) The distribution of agricultural practices in the UK on a 5 x 5 km grid, taken together with the atmospheric dispersion model allows the estimation of the total activity reaching man via food, and hence the collective dose. This combination of models and data arrays allows assessments to be made of the collective dose due to atmospheric releases of radioactive materials at any geographical location in the United Kingdom. (author)

  2. Preliminary study of dose equivalent evaluation for residents in radioactivity contaminated rebar buildings

    International Nuclear Information System (INIS)

    Chen, W.L.; Liao, C.C.; Wang, M.T.; Chen, F. D.

    1998-01-01

    It has recently been found that several resident and office buildings in Taiwan were constructed with 60 Co-contaminated reinforcing steel bar (rebar). Both governmental officials and the residents of such buildings have been concerned about this finding. In order to respond to the situation, the government has adopted a number of remedial measures, including full-scale radiation survey, dose evaluation and physical examinations of residents. This article presents three methods for evaluating the dose equivalents of the residents living in the contaminated rebar buildings by means of γ-ray survey, necklace-type thermoluminescence dosimeters (TLDs) and the human lymphocyte chromosome aberration analyses. The results reveal that the dose evaluation by γ-ray survey is rather conservative. Generally for the residents whose annual dose equivalents are greater than 5 mSv (0.5 rem) by γ-ray survey, the dose equivalents from necklace-type TLDs are only within the range of 20 to 50% of the evaluated values mentioned above. For chromosome analyses, at least 500 lymphocyte cells were scored and analyzed for each resident. Most of the chromosome analysis data show that the dose equivalents received by residents are lower than the detection limit of the method (100 mSv) and quite different from the estimated dose obtained from either γ-ray survey or necklace-type TLD measurements

  3. Comprehensive analysis of Curie-point depths and lithospheric effective elastic thickness at Arctic Region

    Science.gov (United States)

    Lu, Y.; Li, C. F.

    2017-12-01

    Arctic Ocean remains at the forefront of geological exploration. Here we investigate its deep geological structures and geodynamics on the basis of gravity, magnetic and bathymetric data. We estimate Curie-point depth and lithospheric effective elastic thickness to understand deep geothermal structures and Arctic lithospheric evolution. A fractal exponent of 3.0 for the 3D magnetization model is used in the Curie-point depth inversion. The result shows that Curie-point depths are between 5 and 50 km. Curie depths are mostly small near the active mid-ocean ridges, corresponding well to high heat flow and active shallow volcanism. Large curie depths are distributed mainly at continental marginal seas around the Arctic Ocean. We present a map of effective elastic thickness (Te) of the lithosphere using a multitaper coherence technique, and Te are between 5 and 110 km. Te primarily depends on geothermal gradient and composition, as well as structures in the lithosphere. We find that Te and Curie-point depths are often correlated. Large Te are distributed mainly at continental region and small Te are distributed at oceanic region. The Alpha-Mendeleyev Ridge (AMR) and The Svalbard Archipelago (SA) are symmetrical with the mid-ocean ridge. AMR and SA were formed before an early stage of Eurasian basin spreading, and they are considered as conjugate large igneous provinces, which show small Te and Curie-point depths. Novaya Zemlya region has large Curie-point depths and small Te. We consider that fault and fracture near the Novaya Zemlya orogenic belt cause small Te. A series of transform faults connect Arctic mid-ocean ridge with North Atlantic mid-ocean ridge. We can see large Te near transform faults, but small Curie-point depths. We consider that although temperature near transform faults is high, but mechanically the lithosphere near transform faults are strengthened.

  4. Evaluation of fading factor and self-dose for glass dosimeter and thermoluminescence dosimeter

    International Nuclear Information System (INIS)

    Yamasaki, T.; Yamanishi, H.; Miyake, H.; Komura, K.

    2000-01-01

    The glass dosimeter (GD) and thermoluminescence dosimeter (TLD) are both passive radiation detectors. They are often used for measuring environmental radiation. In order to measure low dose rate preciously, it is important to evaluate decreased dose due to fading and self-dose during the exposure period. We evaluate the fading factor and self-dose of thee passive detectors, GD and TLD. We select Ogoya tunnel for the experiment. The tunnel is suitable field for measuring faded dose and self-dose because it is low cosmic radiation. At the center of the tunnel, the intensity of cosmic ray is reduced to about 1/177 than the outside of the funnel. We prepared two sets of dosimeters. One set consists of five GDs, five TLDs and some pre-irradiated GDs and TLDs that are exposed to standard radiation of 4 mGy by Cs-137. These dosimeters are put in the 10 cm thick lead box in order to shield the terrestrial gamma ray. One set is located at the center of the tunnel and the other is the outside of the funnel. The dosimeters were exposed for ten months, from May 1998 to March 1999. After the exposure, the readers of dosimeters are carried into the funnel to read out the signals promptly as soon as taking out the dosimeters. As a result of the measurement, four kinds of data are taken for GD and TLD respectively. Assumed that the self-dose and cosmic ray are constant during exposure, the four independent unknown quantities, a self-dose a dose due to cosmic ray and a fading coefficient at the center of the tunnel and at the outside, are considered. Therefore four simultaneous equations should be obtained. From these examinations, the faded dose of GD is less than 1%, but that of TLD is about 16% during ten months. The coefficient for compensation of fading of GD and TLD is given as the half of the each value. At the outside of the tunnel, the measured dose rate of cosmic ray that can pass through the 10 cm lead is evaluated to be about 16 nGy/h by both detectors. The self-dose

  5. Evaluation of effective dose from CT scans for overweight and obese adult patients using the VirtualDose software

    International Nuclear Information System (INIS)

    Liang, Baohui; Gao, Yiming; Chen, Zhi; Xu, X. George

    2017-01-01

    This paper evaluates effective dose (ED) of overweight and obese patients who undergo body computed tomography (CT) examinations. ED calculations were based on tissue weight factors in the International Commission on Radiological Protection Publication 103 (ICRP 103). ED per unit dose length product (DLP) are reported as a function of the tube voltage, body mass index (BMI) of patient. The VirtualDose software was used to calculate ED for male and female obese phantoms representing normal weight, overweight, obese 1, obese 2 and obese 3 patients. Five anatomic regions (chest, abdomen, pelvis, abdomen/pelvis and chest/abdomen/pelvis) were investigated for each phantom. The conversion factors were computed from the DLP, and then compared with data previously reported by other groups. It was observed that tube voltage and BMI are the major factors that influence conversion factors of obese patients, and that ED computed using ICRP 103 tissue weight factors were 24% higher for a CT chest examination and 21% lower for a CT pelvis examination than the ED using ICRP 60 factors. For body CT scans, increasing the tube voltage from 80 to 140 kVp would increase the conversion factors by as much as 19-54% depending on the patient's BMI. Conversion factor of female patients was ∼7% higher than the factors of male patients. DLP and conversion factors were used to estimate ED, where conversion factors depended on tube voltage, sex, BMI and tissue weight factors. With increasing number of obese individuals, using size-dependence conversion factors will improve accuracy, in estimating patient radiation dose. (authors)

  6. Evaluation of concave dose distributions created using an inverse planning system

    International Nuclear Information System (INIS)

    Hunt, Margie A.; Hsiung, C.-Y.; Spirou, Spirodon V.; Chui, C.-S.; Amols, Howard I.; Ling, Clifton C.

    2002-01-01

    Purpose: To evaluate and develop optimum inverse treatment planning strategies for the treatment of concave targets adjacent to normal tissue structures. Methods and Materials: Optimized dose distributions were designed using an idealized geometry consisting of a cylindrical phantom with a concave kidney-shaped target (PTV) and cylindrical normal tissues (NT) placed 5-13 mm from the target. Targets with radii of curvature from 1 to 2.75 cm were paired with normal tissues with radii between 0.5 and 2.25 cm. The target was constrained to a prescription dose of 100% and minimum and maximum doses of 95% and 105% with relative penalties of 25. Maximum dose constraint parameters for the NT varied from 10% to 70% with penalties from 10 to 1000. Plans were evaluated using the PTV uniformity index (PTV D max /PTV D 95 ) and maximum normal tissue doses (NT D max /PTV D 95 ). Results: In nearly all situations, the achievable PTV uniformity index and the maximum NT dose exceeded the corresponding constraints. This was particularly true for small PTV-NT separations (5-8 mm) or strict NT dose constraints (10%-30%), where the achievable doses differed from the requested by 30% or more. The same constraint parameters applied to different PTV-NT separations yielded different dose distributions. For most geometries, a range of constraints could be identified that would lead to acceptable plans. The optimization results were fairly independent of beam energy and radius of curvature, but improved as the number of beams increased, particularly for small PTV-NT separations or strict dose constraints. Conclusion: Optimized dose distributions are strongly affected by both the constraint parameters and target-normal tissue geometry. Standard site-specific constraint templates can serve as a starting point for optimization, but the final constraints must be determined iteratively for individual patients. A strategy whereby NT constraints and penalties are modified until the highest

  7. Curie Depth Analysis of the Salton Sea Region, Southern California

    Science.gov (United States)

    Mickus, Kevin; Hussein, Musa

    2016-02-01

    Aeromagnetic data were analyzed to determine the bottom of magnetic bodies that might be related to the Curie point depth (CPD) by 2D spectral and 3D inversion methods within the Salton Trough and the surrounding region in southern California. The bottom of the magnetic bodies for 55 × 55 km windows varied in depth between 11 and 23 km in depth using 2D spectral methods. Since the 55 × 55 km square window may include both shallow and deep source, a 3D inversion method was used to provide better resolution of the bottom of the magnetic bodies. The 3D models indicate the depth to the bottom of the magnetic bodies varied between 5 and 23 km. Even though both methods produced similar results, the 3D inversion method produced higher resolution of the CPD depths. The shallowest depths (5-8 km) occur along and west of the Brawley Seismic Zone and the southwestern portion of the Imperial Valley. The source of these shallow CPD values may be related to geothermal systems including hydrothermal circulation and/or partially molten material. Additionally, shallow CPD depths (7-12 km) were found in a northwest-trending zone in the center of the Salton Trough. These depths coincide with previous seismic analyses that indicated a lower crustal low velocity region which is believed to be caused by partially molten material. Lower velocity zones in several regions may be related to fracturing and/or hydrothermal fluids. If the majority of these shallow depths are related to temperature, they are likely associated with the CPD, and the partially molten material extends over a wider zone than previously known. Greater depths within the Salton Trough coincide with the base of basaltic material and/or regions of intense metamorphism intruded by mafic material in the middle/lower crust.

  8. The evaluation of dose of TSEI with TLD and diode detector of the uterine cervix cancer

    International Nuclear Information System (INIS)

    Je, Young Wan; Na, Keyung Su; Yoon, Il Kyu; Park, Heung Deuk

    2005-01-01

    To evaluate radiation dose and accuracy with TLD and diode detector when treat total skin with electron beam. Using Stanford Technique, we treated patient with Mycosis Fungoides. 6 MeV electron beam of LINAC was used and the SSD was 300 cm. Also, acrylic speller(0.8 cm) was used. The patient position was 6 types and the gantry angle was 64, 90 and 116 degree. The patient's skin dose and the output were detected 5 to 6 times with TLD and diode. The deviations of dose detected with TLD from tumor dose were CA + 6%, thigh + 8%, umbilicus + 4%, calf - 8%, vertex - 74.4%, deep axillae - 10.2%, anus and testis - 87%, sole - 86% and nails shielded with 4 mm lead + 4%. The deviations of dose detected with diode were - 4.5% ∼ + 5% at the patient center and - 1.1% ∼ + 1% at the speller. The deviation of total skin dose was + 8% ∼ - 8% and that deviation was within the acceptable range(±10%). The boost dose was irradiated for the low dose areas(vertex, anus, sole). The electron beam output detected at the sootier was stable. It is thought that the deviation of dose at patient center detected with diode was induced by detection point and patient position.

  9. Evaluation of dose distributions in gamma chamber using glass plate detector

    Directory of Open Access Journals (Sweden)

    Narayan Pradeep

    2008-01-01

    Full Text Available A commercial glass plate of thickness 1.75 mm has been utilized for evaluation of dose distributions inside the irradiation volume of gamma chamber using optical densitometry technique. The glass plate showed linear response in the dose range 0.10 Kilo Gray (kGy to 10 kGy of cobalt-60 gamma radiation with optical sensitivity 0.04 Optical Density (OD /kGy. The change in the optical density at each identified spatial dose matrix on the glass plate in relation to the position in the irradiation volume has been presented as dose distributions inside the gamma chamber. The optical density changes have been graphically plotted in the form of surface diagram of color washes for different percentage dose rate levels as isodose distributions in gamma chamber. The variation in dose distribution inside the gamma chamber unit, GC 900, BRIT India make, using this technique has been observed within ± 15%. This technique can be used for routine quality assurances and dose distribution validation of any gamma chamber during commissioning and source replacement. The application of commercial glass plate for dose mapping in gamma chambers has been found very promising due to its wider dose linearity, quick measurement, and lesser expertise requirement in application of the technique.

  10. Evaluation and comparison of absorbed dose for electron beams by LiF and diamond dosimeters

    International Nuclear Information System (INIS)

    Mosia, G.J.; Chamberlain, A.C.

    2007-01-01

    The absorbed dose response of LiF and diamond thermoluminescent dosimeters (TLDs), calibrated in 60 Co γ-rays, has been determined using the MCNP4B Monte Carlo code system in mono-energetic megavoltage electron beams from 5 to 20 MeV. Evaluation of the dose responses was done against the dose responses of published works by other investigators. Dose responses of both dosimeters were compared to establish if any relation exists between them. The dosimeters were irradiated in a water phantom with the centre of their top surfaces (0.32x0.32 cm 2 ), placed at d max perpendicular to the radiation beam on the central axis. For LiF TLD, dose responses ranged from 0.945±0.017 to 0.997±0.011. For the diamond TLD, the dose response ranged from 0.940±0.017 to 1.018±0.011. To correct for dose responses by both dosimeters, energy correction factors were generated from dose response results of both TLDs. For LiF TLD, these correction factors ranged from 1.003 up to 1.058 and for diamond TLD the factors ranged from 0.982 up to 1.064. The results show that diamond TLDs can be used in the place of the well-established LiF TLDs and that Monte Carlo code systems can be used in dose determinations for radiotherapy treatment planning

  11. Evaluation of occupational dose from the special procedures guided by fluoroscopy: cardiac catheterism

    International Nuclear Information System (INIS)

    Silva, Amanda Juliene da

    2011-01-01

    The purpose of this study was to evaluate the dose received by health professionals in the hemodynamic sector of a university hospital in Sao Paulo city. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account sociodemographic variables and variables related to the work with ionizing radiation. The assessment of occupational doses was performed by consulting of the individual dose records of the institution database from 2000 to 2009. A total of 240 records was evaluated, corresponding to 38 active professionals (2009), divided in different professional category: physician, nurses, radiologic technologists and nursing assistants. The annual doses were compared with the limits established by national regulatory authorities. Based on the effective doses received and recorded during the studied period, experimental measures were performed with TL dosimeters in five physicians to evaluate the equivalent dose, in the left hand, during hemodynamic procedures. In addition, the radioprotection measures adopted by health professionals were verified. This study allowed delineating the profile of medical staff that integrates the hemodynamic service as well as knowing the distribution of their doses in relation to limits over the years. (author)

  12. Evaluation of dose according to the volume and respiratory range during SBRT in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Deuk Hee [Dept. of Radiation Oncology, Busan Paik Hospital, Inje University, Busan (Korea, Republic of); Park, Eun Tae; Kim, Jung Hoon; Kang, Se Seik [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

    2016-09-15

    Stereotactic body radiotherapy is effective technic in radiotherapy for low stage lung cancer. But lung cancer is affected by respiratory so accurately concentrate high dose to the target is very difficult. In this study, evaluated the target volume according to how to take the image. And evaluated the dose by photoluminescence glass dosimeter according to how to contour the volume and respiratory range. As a result, evaluated the 4D CT volume was 10.4 cm{sup 3} which was closest value of real size target. And in dose case is internal target volume dose was 10.82, 16.88, 21.90 Gy when prescribed dose was 10, 15, 20 Gy and it was the highest dose. Respiratory gated radiotherapy dose was more higher than internal target volume. But it made little difference by respiratory range. Therefore, when moving cancer treatment, acquiring image by 4D CT, contouring internal target volume and respiratory gated radiotherapy technic would be the best way.

  13. Evaluation of dose according to the volume and respiratory range during SBRT in lung cancer

    International Nuclear Information System (INIS)

    Lee, Deuk Hee; Park, Eun Tae; Kim, Jung Hoon; Kang, Se Seik

    2016-01-01

    Stereotactic body radiotherapy is effective technic in radiotherapy for low stage lung cancer. But lung cancer is affected by respiratory so accurately concentrate high dose to the target is very difficult. In this study, evaluated the target volume according to how to take the image. And evaluated the dose by photoluminescence glass dosimeter according to how to contour the volume and respiratory range. As a result, evaluated the 4D CT volume was 10.4 cm 3 which was closest value of real size target. And in dose case is internal target volume dose was 10.82, 16.88, 21.90 Gy when prescribed dose was 10, 15, 20 Gy and it was the highest dose. Respiratory gated radiotherapy dose was more higher than internal target volume. But it made little difference by respiratory range. Therefore, when moving cancer treatment, acquiring image by 4D CT, contouring internal target volume and respiratory gated radiotherapy technic would be the best way

  14. Fetus absorbed dose evaluation in head and neck radiotherapy procedures of pregnant patients

    International Nuclear Information System (INIS)

    Camargo da C, E.; Ribeiro da R, L. A.; Santos B, D. V.

    2014-08-01

    Each year a considerable amount of pregnant women needs to be submitted to radiotherapeutic procedures to combat malignant tumors. Radiation therapy is often a treatment of choice for these patients. It is possible to use shielding and beam positioning such that the potential dose to the fetus can be minimized. In this work the head and neck cancer treatment of a pregnant patient was experimentally simulated. The patient was simulated by an anthropomorphic Alderson phantom and the absorbed dose to the fetus was evaluated using micro-rod TLD-100 detectors in two conditions, namely protecting the patients abdomen with a 7 cm lead layer and using no abdomen shielding. The aim of this experiment was to evaluate the efficiency of the abdomen protection in reducing the fetus absorbed dose. Irradiations were performed with a Trilogy linear accelerator using x-rays of 6 MV. A total dose of 50 Gy to the target volume was delivered. The fetus doses evaluated with and without the lead shielding were, respectively, 0.52±0.039 and (0.88±0.052) c Gy, corresponding to a dose reduction of 59%. The dose (0.52±0.039) c Gy is within the zone of biological tolerance for the fetus. (Author)

  15. Evaluation of mixed energy neutron doses using TLD NG-67 type

    International Nuclear Information System (INIS)

    Akhadi, Mukhlis; Thoyib Thamrin, M; Usmiyati Dewi, K.

    2000-01-01

    A research has been carried out to develop dose evaluation method of mixed neutron source with its neutron doses can be classified to two groups, I.e neutron doses with energy ≥ 0.5 eV and thermal neutron doses with energy less than 0.5 e V consist of epithermal and fast neutron, but in this research they were classified as fast neutron. Development of this dose evaluation method was carried out by sensitivity (S) intercomparison of TLD-600 to fast neutron, mixed energy neutron of nuclear rectors, and thermal neutron. From the experiment it was obtained that the value of Sfast : Sreactor : Sthermal = 0.005 : 0.010 : 1. Calibration factor (CF) of TLD is defined as 1/S. from the sensitivity data it can be obtained that the value of Cffast : Cfreactor : Cfthermal = 200 :100 : 1. The value of Cfreactor can be applied for mixed energy neutron doses evaluation of TLD-600. Key word : dosemeter, neutron dose, calibration factor, fast neutron, thermal neutron, nuclear reactor

  16. Fetus absorbed dose evaluation in head and neck radiotherapy procedures of pregnant patients

    Energy Technology Data Exchange (ETDEWEB)

    Camargo da C, E.; Ribeiro da R, L. A.; Santos B, D. V., E-mail: etieli@ird.gov.br [Instituto de Radioprotecao e Dosimetria / CNEN, Av. Salvador Allende s/n, Barra de Tijuca, 22783-127 Rio de Janeiro (Brazil)

    2014-08-15

    Each year a considerable amount of pregnant women needs to be submitted to radiotherapeutic procedures to combat malignant tumors. Radiation therapy is often a treatment of choice for these patients. It is possible to use shielding and beam positioning such that the potential dose to the fetus can be minimized. In this work the head and neck cancer treatment of a pregnant patient was experimentally simulated. The patient was simulated by an anthropomorphic Alderson phantom and the absorbed dose to the fetus was evaluated using micro-rod TLD-100 detectors in two conditions, namely protecting the patients abdomen with a 7 cm lead layer and using no abdomen shielding. The aim of this experiment was to evaluate the efficiency of the abdomen protection in reducing the fetus absorbed dose. Irradiations were performed with a Trilogy linear accelerator using x-rays of 6 MV. A total dose of 50 Gy to the target volume was delivered. The fetus doses evaluated with and without the lead shielding were, respectively, 0.52±0.039 and (0.88±0.052) c Gy, corresponding to a dose reduction of 59%. The dose (0.52±0.039) c Gy is within the zone of biological tolerance for the fetus. (Author)

  17. Bile duct evaluation of potential living liver donors with Gd-EOB-DTPA enhanced MR cholangiography: Single-dose, double dose or half-dose contrast enhanced imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kinner, Sonja, E-mail: Sonja.Kinner@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Steinweg, Verena [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Maderwald, Stefan [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Radtke, Arnold; Sotiropoulos, Georgios [Department of General Surgery, University Hospital Essen (Germany); Forsting, Michael; Schroeder, Tobias [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany)

    2014-05-15

    Introduction: Detailed knowledge of the biliary anatomy is essential to avoid complications in living donor liver transplantation. The aim of this study was to determine the optimal dosage of Gd-EOB-DTPA for contrast-enhanced magnetic resonance cholangiography (ce-MRC) with reference to contrast-enhanced CT cholangiography (ce-CTC). Materials and methods: 30 potential living liver donors (PLLD) underwent both ce-CTC and ce-MRC. Ten candidates each received single, double or half-dose Gd-EOB-DTPA. Ce-MRC images with and without inversion recovery pulses (T1w ± IR) were acquired 20–30 min after intravenous contrast injection. Image data was quantitatively and qualitatively reviewed by two radiologists based on a on a 5-point scale. Data sets were compared using a Mann–Whitney-U-test or Wilcoxon-rank-sum-test. Kappa values were also calculated. Results: All image series provided sufficient diagnostic information both showing normal biliary anatomy and variant bile ducts. Ce-CTC showed statistically significant better results compared to all ce-MRC data sets. T1w MRC with single dose Gd-EOB-DTPA proved to be superior to half and double dose in subjective and objective evaluation without a statistically significant difference. Conclusions: Ce-MRC is at any dosage inferior to ce-CTC. As far as preoperative planning of bile duct surgery is focused on the central biliary anatomy, ce-MRC can replace harmful ce-CTC strategies, anyway. Best results were seen with single dose GD-EOB-DTPA on T1w MRC+IR.

  18. Evaluation of dose equivalent rate distribution in JCO critical accident by radiation transport calculation

    CERN Document Server

    Sakamoto, Y

    2002-01-01

    In the prevention of nuclear disaster, there needs the information on the dose equivalent rate distribution inside and outside the site, and energy spectra. The three dimensional radiation transport calculation code is a useful tool for the site specific detailed analysis with the consideration of facility structures. It is important in the prediction of individual doses in the future countermeasure that the reliability of the evaluation methods of dose equivalent rate distribution and energy spectra by using of Monte Carlo radiation transport calculation code, and the factors which influence the dose equivalent rate distribution outside the site are confirmed. The reliability of radiation transport calculation code and the influence factors of dose equivalent rate distribution were examined through the analyses of critical accident at JCO's uranium processing plant occurred on September 30, 1999. The radiation transport calculations including the burn-up calculations were done by using of the structural info...

  19. Special Workshop of Marie Curie Fellows on Research and Training in Physics and Technology.

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    Photo 0210008_05a: Dr, Rolf Landua (CERN) explaining to participants of the Marie Curie Workshop (held at CERN 3-4 October 2002) the ATHENA experiment and the Antiproton Decelerator. Photo 0210008_06a: Dr, Rolf Landua (CERN) explaining to participants of the Marie Curie Workshop (held at CERN 3-4 October 2002) the ATHENA experiment and the Antiproton Decelerator. Photo 0210008_08a: Dr, Rolf Landua (CERN) explaining to participants of the Marie Curie Workshop (held at CERN 3-4 October 2002) the ATHENA experiment and the Antiproton Decelerator. Photo 0210008_09a: Dr, Rolf Landua (CERN) explaining to participants of the Marie Curie Workshop (held at CERN 3-4 October 2002) the ATHENA experiment and the Antiproton Decelerator.

  20. The medical applications of the discoveries of Marie Sklodowska-Curie

    International Nuclear Information System (INIS)

    Krawczyk, M.

    2011-01-01

    In this work, the author indicates what have been the applications of the discoveries of Marie Curie in the field of medicine and how these discoveries have contributed in particular to the development of oncologic radiotherapy. (O.M.)

  1. Novel Radiobiological Gamma Index for Evaluation of 3-Dimensional Predicted Dose Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Iori, E-mail: sumida@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Yamaguchi, Hajime; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yoshikawa, Nobuhiko; Yamada, Yuji [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Suzuki, Osamu; Seo, Yuji [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Isohashi, Fumiaki [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan)

    2015-07-15

    Purpose: To propose a gamma index-based dose evaluation index that integrates the radiobiological parameters of tumor control (TCP) and normal tissue complication probabilities (NTCP). Methods and Materials: Fifteen prostate and head and neck (H&N) cancer patients received intensity modulated radiation therapy. Before treatment, patient-specific quality assurance was conducted via beam-by-beam analysis, and beam-specific dose error distributions were generated. The predicted 3-dimensional (3D) dose distribution was calculated by back-projection of relative dose error distribution per beam. A 3D gamma analysis of different organs (prostate: clinical [CTV] and planned target volumes [PTV], rectum, bladder, femoral heads; H&N: gross tumor volume [GTV], CTV, spinal cord, brain stem, both parotids) was performed using predicted and planned dose distributions under 2%/2 mm tolerance and physical gamma passing rate was calculated. TCP and NTCP values were calculated for voxels with physical gamma indices (PGI) >1. We propose a new radiobiological gamma index (RGI) to quantify the radiobiological effects of TCP and NTCP and calculate radiobiological gamma passing rates. Results: The mean RGI gamma passing rates for prostate cases were significantly different compared with those of PGI (P<.03–.001). The mean RGI gamma passing rates for H&N cases (except for GTV) were significantly different compared with those of PGI (P<.001). Differences in gamma passing rates between PGI and RGI were due to dose differences between the planned and predicted dose distributions. Radiobiological gamma distribution was visualized to identify areas where the dose was radiobiologically important. Conclusions: RGI was proposed to integrate radiobiological effects into PGI. This index would assist physicians and medical physicists not only in physical evaluations of treatment delivery accuracy, but also in clinical evaluations of predicted dose distribution.

  2. Methods to verify absorbed dose of irradiated containers and evaluation of dosimeters

    International Nuclear Information System (INIS)

    Gao Meixu; Wang Chuanyao; Tang Zhangxong; Li Shurong

    2001-01-01

    The research on dose distribution in irradiated food containers and evaluation of several methods to verify absorbed dose were carried out. The minimum absorbed dose of treated five orange containers was in the top of the highest or in the bottom of lowest container. D max /D min in this study was 1.45 irradiated in a commercial 60 Co facility. The density of orange containers was about 0.391g/cm 3 . The evaluation of dosimeters showed that the PMMA-YL and clear PMMA dosimeters have linear relationship with dose response, and the word NOT in STERIN-125 and STERIN-300 indicators were covered completely at the dosage of 125 and 300 Gy respectively. (author)

  3. On the equivalence of dilute antiferromagnets and ferromagnets in random external fields: Curie-Weiss models

    International Nuclear Information System (INIS)

    Perez, J.F.; Pontin, L.F.; Segundo, J.A.B.

    1985-01-01

    Using a method proposed by van Hemmen the free energy of the Curie-Weiss version of the site-dilute antiferromagnetic Ising model is computed, in the presence of an uniform magnetic field. The solution displays an exact correspondence between this model and the Curie-Weiss version of the Ising model in the presence of a random magnetic field. The phase diagrams are discussed and a tricritical point is shown to exist. (Author) [pt

  4. Effect of Gd doping and O deficiency on the Curie temperature of EuO

    KAUST Repository

    Jutong, Nuttachai

    2015-01-27

    The effect of Gd doping and O deficiency on the electronic structure, exchange interaction, and Curie temperature of EuO in the cubic and tetragonal phases is studied by means of density functional theory. For both defects, the Curie temperature is found to exhibit a distinct maximum as a function of the defect concentration. The existence of optimal defect concentrations is explained by the interplay of the on-site, RKKY, and superexchange contributions to the magnetism.

  5. Effect of Gd doping and O deficiency on the Curie temperature of EuO

    KAUST Repository

    Jutong, Nuttachai; Eckern, Ulrich; Mairoser, Thomas; Schwingenschlö gl, Udo

    2015-01-01

    The effect of Gd doping and O deficiency on the electronic structure, exchange interaction, and Curie temperature of EuO in the cubic and tetragonal phases is studied by means of density functional theory. For both defects, the Curie temperature is found to exhibit a distinct maximum as a function of the defect concentration. The existence of optimal defect concentrations is explained by the interplay of the on-site, RKKY, and superexchange contributions to the magnetism.

  6. Two Japanese scientists and the Curie family, Nobuo Yamada and Toshiko Yuasa

    International Nuclear Information System (INIS)

    Kawashima, Keiko

    2012-01-01

    This article presents two Japanese scientists, a man and a woman, who worked with Pierre and Marie Curie, and with Irene and Pierre Joliot-Curie. Nobuo Yamada (1896-1927) was the first Japanese researcher at the French Radium Institute; he was a specialist of researches on helium. Toshiko Yuasa was the first Japanese scientist to obtain a permanent appointment in France. Her researches were a contribution to the investigation of the continuous spectrum of beta radiation emitted by artificial radioactive bodies

  7. Potential influence of new doses of A-bomb after re-evaluation of epidemiological research

    International Nuclear Information System (INIS)

    Maruyama, T.

    1983-01-01

    Since the peaceful use of atomic energy appears essential for future human existence, we must provide risk estimates from low-dose exposures to human beings. The largest body of human data has been derived from the studies of atomic bomb survivors in Hiroshima and Nagasaki. Recently, it was proposed by an Oak Ridge National Laboratory group that the current free-in-air doses of atomic bombs are significantly different from the doses recalculated on the basis of the new output spectra of neutrons and gamma rays from the atomic bombs which were declassified by the US Department of Energy in 1976. A joint commission on dose re-evaluation of the United States of America and Japan was established in 1981 to pursue the dose reassessment programme between US and Japanese research groups and to decide an agreed best estimate of organ or tissue doses in survivors as soon as possible. The paper reviews the physical concepts of the re-evaluation of atomic bomb doses and discusses the potential influence of new dosimetric parameters on the epidemiological studies of the atomic bomb survivors in future, although the re-assessment programme is still in progress. (author)

  8. Dose area product evaluations with Gafchromic XR-R films and a flat-bed scanner.

    Science.gov (United States)

    Rampado, O; Garelli, E; Deagostini, S; Ropolo, R

    2006-12-07

    Gafchromic XR-R films are a useful tool to evaluate entrance skin dose in interventional radiology. Another dosimetric quantity of interest in diagnostic and interventional radiology is the dose area product (DAP). In this study, a method to evaluate DAP using Gafchromic XR-R films and a flat-bed scanner was developed and tested. Film samples were exposed to an x-ray beam of 80 kVp over a dose range of 0-10 Gy. DAP measurements with films were obtained from the digitalization of a film sample positioned over the x-ray beam window during the exposure. DAP values obtained with this method were compared for 23 cardiological interventional procedures with DAP values displayed by the equipment. The overall one-sigma dose measurement uncertainty depended on the absorbed dose, with values below 6% for doses above 1 Gy. A maximum discrepancy of 16% was found, which is of the order of the differences in the DAP measurements that may occur with different calibration procedures. Based on the results presented, after an accurate calibration procedure and a thorough inspection of the relationship between the actual dose and the direct measured quantity (net optical density or net pixel value variation), Gafchromic XR-R films can be used to assess the DAP.

  9. Study on the evaluation method of radiation dose rate around spent fuel shipping casks

    International Nuclear Information System (INIS)

    Yamakoshi, Hisao

    1986-01-01

    This study aims at developing a simple calculation method which can evaluate radiation dose rate around casks with high accuracy in a short time. The method is based on a concept of the radiation shielding characteristics of cask walls. The concept was introduced to replace for ordinary radiation shielding calculation which requires a long calculation time and a large memory capacity of a computer in the matrix calculation. For the purpose of verifying the accuracy and reliability of the new method, it was applied to the analysis of the dose rate distribution around actual casks, which had been measured. The results of the analysis revealed that the newly proposed method was excellent for the forecast of radiation dose rate distribution around casks in view of the accuracy and calculation time. The short calculation time and high accuracy by the proposed method were attained by dividing the whole procedure of ordinary fine radiation shielding calculation into the calculation of radiation dose rate on a cask surface by the matrix expression of the characteristic function and the calculation of dose rate distribution using the simple analytical expression of dose rate distribution around casks. The effect of the heterogeneous array of spent fuel in different burnup state on dose rate distribution around casks was evaluated by this method. (Kako, I.)

  10. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    International Nuclear Information System (INIS)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won

    2011-01-01

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  11. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  12. Evaluation of glasses containing cadmium for high dose dosimetry by the thermoluminescence technique

    International Nuclear Information System (INIS)

    Carvalho, Gabriel Soares Marchiori de; Ferreira, Pamela Zati; Cunha, Diego Merigue da; Dantas, Noelio Oliveira; Silva, Anielle C.A.; Perini, Ana Paula; Neves, Lucio Pereira; Carrera, Betzabel Noemi Silva; Watanabe, Shigueo

    2016-01-01

    New glass matrices were evaluated for high dose dosimetry by the thermoluminescence technique. Their nominal composition are 20Li_2CO_3.10Al_2O_3.15CdO.55B_2O_3 and 20Li_2CO_3.10Al_2O_3.20CdO.50B_2O_3 (mol%). The glass matrices were irradiated with different doses: 50, 100, 200, 500, 700 and 900 Gy, and the thermoluminescence emission curves were obtained for each of these values. The results show a great potential of using these matrices in high dose dosimetry. (author)

  13. Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

    Science.gov (United States)

    Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

    2012-01-01

    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

  14. Internal dose evaluation of workers involved in radioisotopes and radiopharmaceuticals handling for medical use

    International Nuclear Information System (INIS)

    Cesar, R.B.P.; Mesquita, C.H. de

    1987-01-01

    The internal dose levels of IPEN workers, involved in the production of radioisotopes and radiopharmaceuticals for medical use are surveyed. In this production, the workers were splited in six group: research and development, routine production, quality control, packaging, radiological protection and maintenance. The internal dose was evaluated according to the models described by ICRP-30, from the results obtained in the whole body counters monitoring. (C.G.C.) [pt

  15. Final Technical Report. A critical evaluation of patent doses in screening mammography

    International Nuclear Information System (INIS)

    Hintenlang, David E.

    2004-01-01

    This project was designed to develop tools that would permit an accurate assessment of the patient doses that are received in screening mammography, and to subsequently demonstrate those tools to perform an objective evaluation of patient doses. The project also provides an educational component through the integration of multiple aspects of applied radiological engineering to provide students with realistic applications of many of the theoretical principles that are studied as part of their graduate curriculum

  16. Evaluation of functioning of high dose rate brachytherapy at the Instituto Nacional do Cancer

    International Nuclear Information System (INIS)

    Guedes, Laura M.A.; Barreto, Rodrigo V.; Silva, Penha M.; Macedo, Afranio A.; Borges, Solange C.; Martinez, Valeria P.O.

    2001-01-01

    Quality control tests are very useful tools to assure the quality of patient's treatment. A daily control of the high dose rate micro selectron was performed based on the security parameters of the equipment and on the quickness of performance. The purpose of this report is to evaluate and to discuss the errors found during the first three years with the high dose rate brachytherapy, at the Instituto Nacional de Cancer. (author)

  17. Evaluation of a new commercial Monte Carlo dose calculation algorithm for electron beams.

    Science.gov (United States)

    Vandervoort, Eric J; Tchistiakova, Ekaterina; La Russa, Daniel J; Cygler, Joanna E

    2014-02-01

    In this report the authors present the validation of a Monte Carlo dose calculation algorithm (XiO EMC from Elekta Software) for electron beams. Calculated and measured dose distributions were compared for homogeneous water phantoms and for a 3D heterogeneous phantom meant to approximate the geometry of a trachea and spine. Comparisons of measurements and calculated data were performed using 2D and 3D gamma index dose comparison metrics. Measured outputs agree with calculated values within estimated uncertainties for standard and extended SSDs for open applicators, and for cutouts, with the exception of the 17 MeV electron beam at extended SSD for cutout sizes smaller than 5 × 5 cm(2). Good agreement was obtained between calculated and experimental depth dose curves and dose profiles (minimum number of measurements that pass a 2%/2 mm agreement 2D gamma index criteria for any applicator or energy was 97%). Dose calculations in a heterogeneous phantom agree with radiochromic film measurements (>98% of pixels pass a 3 dimensional 3%/2 mm γ-criteria) provided that the steep dose gradient in the depth direction is considered. Clinically acceptable agreement (at the 2%/2 mm level) between the measurements and calculated data for measurements in water are obtained for this dose calculation algorithm. Radiochromic film is a useful tool to evaluate the accuracy of electron MC treatment planning systems in heterogeneous media.

  18. A prospective evaluation of hippocampal radiation dose volume effects and memory deficits following cranial irradiation.

    Science.gov (United States)

    Ma, Ting Martin; Grimm, Jimm; McIntyre, Riley; Anderson-Keightly, Heather; Kleinberg, Lawrence R; Hales, Russell K; Moore, Joseph; Vannorsdall, Tracy; Redmond, Kristin J

    2017-11-01

    To prospectively evaluate hippocampal radiation dose volume effects and memory decline following cranial irradiation. Effects of hippocampal radiation over a wide range of doses were investigated by combining data from three prospective studies. In one, adults with small cell lung cancer received hippocampal-avoidance prophylactic cranial irradiation. In the other two, adults with glioblastoma multiforme received neural progenitor cell sparing radiation or no sparing with extra dose delivered to subventricular zone. Memory was measured by the Hopkins Verbal Learning Test-Revised Delayed Recall (HVLT-R DR) at 6 months after radiation. Dose-volume histograms were generated and dose-response data were fitted to a nonlinear model. Of 60 patients enrolled, 30 were analyzable based on HVLT-R DR testing completion status, baseline HVLT-R DR and intracranial metastasis/recurrence or prior hippocampal resection status. We observed a dose-response of radiation to the hippocampus with regard to decline in HVLT-R DR. D50% of the bilateral hippocampi of 22.1 Gy is associated with 20% risk of decline. This prospective study demonstrates an association between hippocampal dose volume effects and memory decline measured by HVLT-R DR over a wide dose range. These data support a potential benefit of hippocampal sparing and encourage continued trial enrollment. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Evaluation of the image quality criteria and study of doses in a mammography department

    International Nuclear Information System (INIS)

    Alcantara, Marcela Costa

    2009-01-01

    The mammographic image quality criteria published by European Commission were implemented in three mammography equipment of a same radiology department in a hospital of Sao Paulo city. Among the mammography equipment, two use the screen-film system and one of them uses the indirect digital system. During the data collection, it was noted the need to conduct a study about image rejection in each mammography equipment. Therefore, this study was realized and, after that, the results in each mammography equipment of image rejection and image percentage that present each quality criterion it were compared. At the same time of this studies, it was realized other study about surface entrance dose and average glandular dose. These doses it was estimated based on different methods published by different groups of researcher, for all combinations anode filter available in the equipment. To estimate the surface entrance dose following the methodology published in Avenue's' guide and the average glandular dose following the Wu' methodology, it was developed a phantom, in different thicknesses of acrylic, to simulate a breast. Finally, the image quality it was associated with the dose received by patient. The digital equipment shows better results in the evaluation of quality criteria, lower rate of image rejection and lower values of average glandular dose and surface entrance dose in all methods studied. But it is not sufficient, because is not adequate for patients with great breast. (author)

  20. SU-E-T-67: Clinical Implementation and Evaluation of the Acuros Dose Calculation Algorithm

    International Nuclear Information System (INIS)

    Yan, C; Combine, T; Dickens, K; Wynn, R; Pavord, D; Huq, M

    2014-01-01

    Purpose: The main aim of the current study is to present a detailed description of the implementation of the Acuros XB Dose Calculation Algorithm, and subsequently evaluate its clinical impacts by comparing it with AAA algorithm. Methods: The source models for both Acuros XB and AAA were configured by importing the same measured beam data into Eclipse treatment planning system. Both algorithms were evaluated by comparing calculated dose with measured dose on a homogeneous water phantom for field sizes ranging from 6cm × 6cm to 40cm × 40cm. Central axis and off-axis points with different depths were chosen for the comparison. Similarly, wedge fields with wedge angles from 15 to 60 degree were used. In addition, variable field sizes for a heterogeneous phantom were used to evaluate the Acuros algorithm. Finally, both Acuros and AAA were tested on VMAT patient plans for various sites. Does distributions and calculation time were compared. Results: On average, computation time is reduced by at least 50% by Acuros XB compared with AAA on single fields and VMAT plans. When used for open 6MV photon beams on homogeneous water phantom, both Acuros XB and AAA calculated doses were within 1% of measurement. For 23 MV photon beams, the calculated doses were within 1.5% of measured doses for Acuros XB and 2% for AAA. When heterogeneous phantom was used, Acuros XB also improved on accuracy. Conclusion: Compared with AAA, Acuros XB can improve accuracy while significantly reduce computation time for VMAT plans

  1. Curie's hypotheses concerning radioactivity and the origin of the elements

    International Nuclear Information System (INIS)

    Kuroda, P.K.

    1999-01-01

    Pierre Curie gave two hypotheses at first; (1) It can be supposed that the radioactive substances borrow the energy, which they release, from an external radiation, and their radiation would then be a secondary radiation, (2) It can be supposed that the radioactive substances draw from themselves the energy which they release. The second hypothesis has shown the more fertile in explaining the properties of the radioactive substances. Consequently, the first hypothesis became more or less forgotten. It appears, however, the first hypothesis should play an important role in explaining the phenomena concerning the origin of the elements. The Oklo Phenomenon has demonstrated that a nuclear fire had once existed on our planet earth and formation of heavy elements was occurring in nature. The author pointed out that the difference in the isotopic compositions of xenon found in meteorites, lunar samples and in the earth's atmosphere can only be explained as due to the alterations of the isotropic compositions of xenon by combined effect of (a) mass-fractionation, (b) spallation, and (c) stellar temperature neutron-capture reactions. The strange xenon components are not isotopically pure substance. Instead, xenon-HL is a mixture of the 244 Pu fission xenon and the xenon whose isotopic compositions is severely altered by a combined effect of the processes (a), (b) and (c) mentioned above. These results also indicate that C1 carbonaceous chondrites, which is generally as the most primitive sample of the solar system material, began to retain its xenon 5.1 billion years ago, when the plutonium to uranium ratio in the solar system was as high as almost 0.6 (atom/atom), while the C2 carbonaceous chondrite began to retain their xenon about 150 million years later and the ordinary chondrites and achondrite about 500 to 600 million years later. This means that the birth of the solar system began soon after the last supernova exploded about 5.1 billion years ago, and the generally

  2. Relevance of a molecular tumour board (MTB) for patients' enrolment in clinical trials: experience of the Institut Curie.

    Science.gov (United States)

    Basse, Clémence; Morel, Claire; Alt, Marie; Sablin, Marie Paule; Franck, Coralie; Pierron, Gaëlle; Callens, Céline; Melaabi, Samia; Masliah-Planchon, Julien; Bataillon, Guillaume; Gardrat, Sophie; Lavigne, Marion; Bonsang, Benjamin; Vaflard, Pauline; Pons Tostivint, Elvire; Dubot, Coraline; Loirat, Delphine; Marous, Miguelle; Geiss, Romain; Clément, Nathalie; Schleiermacher, Gudrun; Kamoun, Choumouss; Girard, Elodie; Ardin, Maude; Benoist, Camille; Bernard, Virginie; Mariani, Odette; Rouzier, Roman; Tresca, Patricia; Servois, Vincent; Vincent-Salomon, Anne; Bieche, Ivan; Le Tourneau, Christophe; Kamal, Maud

    2018-01-01

    High throughput molecular screening techniques allow the identification of multiple molecular alterations, some of which are actionable and can be targeted by molecularly targeted agents (MTA). We aimed at evaluating the relevance of using this approach in the frame of Institut Curie Molecular Tumor Board (MTB) to guide patients with cancer to clinical trials with MTAs. We included all patients presented at Institut Curie MTB from 4 October 2014 to 31 October 2017. The following information was extracted from the chart: decision to perform tumour profiling, types of molecular analyses, samples used, molecular alterations identified and those which are actionable, and inclusion in a clinical trial with matched MTA. 736 patients were presented at the MTB. Molecular analyses were performed in 442 patients (60%). Techniques used included next-generation sequencing, comparative genomic hybridisation array and/or other techniques including immunohistochemistry in 78%, 51% and 58% of patients, respectively. Analyses were performed on a fresh frozen biopsy in 91 patients (21%), on archival tissue (fixed or frozen) in 326 patients (74%) and on both archival and fresh frozen biopsy in 25 patients (6%). At least one molecular alteration was identified in 280 analysed patients (63%). An actionable molecular alteration was identified in 207 analysed patients (47%). Forty-five analysed patients (10%) were enrolled in a clinical trial with matched MTA and 29 additional patients were oriented and included in a clinical trial based on a molecular alteration identified prior to the MTB analysis. Median time between date of specimen reception and molecular results was 28 days (range: 5-168). The implementation of an MTB at Institut Curie enabled the inclusion of 10% of patients into a clinical trial with matched therapy.

  3. Does iterative reconstruction lower CT radiation dose: evaluation of 15,000 examinations.

    Directory of Open Access Journals (Sweden)

    Peter B Noël

    Full Text Available PURPOSE: Evaluation of 15,000 computed tomography (CT examinations to investigate if iterative reconstruction (IR reduces sustainably radiation exposure. METHOD AND MATERIALS: Information from 15,000 CT examinations was collected, including all aspects of the exams such as scan parameter, patient information, and reconstruction instructions. The examinations were acquired between January 2010 and December 2012, while after 15 months a first generation IR algorithm was installed. To collect the necessary information from PACS, RIS, MPPS and structured reports a Dose Monitoring System was developed. To harvest all possible information an optical character recognition system was integrated, for example to collect information from the screenshot CT-dose report. The tool transfers all data to a database for further processing such as the calculation of effective dose and organ doses. To evaluate if IR provides a sustainable dose reduction, the effective dose values were statistically analyzed with respect to protocol type, diagnostic indication, and patient population. RESULTS: IR has the potential to reduce radiation dose significantly. Before clinical introduction of IR the average effective dose was 10.1±7.8mSv and with IR 8.9±7.1mSv (p*=0.01. Especially in CTA, with the possibility to use kV reduction protocols, such as in aortic CTAs (before IR: average14.2±7.8mSv; median11.4mSv /with IR:average9.9±7.4mSv; median7.4mSv, or pulmonary CTAs (before IR: average9.7±6.2mSV; median7.7mSv /with IR: average6.4±4.7mSv; median4.8mSv the dose reduction effect is significant(p*=0.01. On the contrary for unenhanced low-dose scans of the cranial (for example sinuses the reduction is not significant (before IR:average6.6±5.8mSv; median3.9mSv/with IR:average6.0±3.1mSV; median3.2mSv. CONCLUSION: The dose aspect remains a priority in CT research. Iterative reconstruction algorithms reduce sustainably and significantly radiation dose in the clinical routine

  4. Characteristics of 3D gamma evaluation according to phantom rotation error and dose gradient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Hyun; Kim, Dong Su; Kim, Tae Ho; Kang, Seong Hee; Shin, Dong Seok; Noh, Yu Yoon; Suh, Tae Seok [Dept. of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Medicine, the Catholic University of Korea, Seoul (Korea, Republic of); Cho, Min Seok [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2016-12-15

    In intensity modulated radiation therapy (IMRT) quality assurance (QA) using dosimetric phantom, a spatial uncertainty induced from phantom set-up inevitably occurs and gamma index that is used to evaluate IMRT plan quality can be affected differently by a combination of the spatial uncertainty and magnitude of dose gradient. In this study, we investigated the impacts of dose gradient and the phantom set-up error on 3D gamma evaluation. In this study, we investigated the characteristics of gamma evaluation according to dose gradient and phantom rotation axis. As a result, 3D gamma had better performance than 2D gamma. Therefore, it can be useful for IMRT QA analysis at clinical field.

  5. Air contamination measurements for the evaluation of internal dose to workers in nuclear medicine departments

    Science.gov (United States)

    De Massimi, B.; Bianchini, D.; Sarnelli, A.; D'Errico, V.; Marcocci, F.; Mezzenga, E.; Mostacci, D.

    2017-11-01

    Radionuclides handled in nuclear medicine departments are often characterized by high volatility and short half-life. It is generally difficult to monitor directly the intake of these short-lived radionuclides in hospital staff: this makes measuring air contamination of utmost interest. The aim of the present work is to provide a method for the evaluation of internal doses to workers in nuclear medicine, by means of an air activity sampling detector, to ensure that the limits prescribed by the relevant legislation are respected. A continuous air sampling system measures isotope concentration with a Nal(TI) detector. Energy efficiency of the system was assessed with GEANT4 and with known activities of 18F. Air is sampled in a number of areas of the nuclear medicine department of the IRST-IRCCS hospital (Meldola- Italy). To evaluate committed doses to hospital staff involved (doctors, technicians, nurses) different exposure situations (rooms, times, radionuclides etc) were considered. After estimating the intake, the committed effective dose has been evaluated, for the different radionuclides, using the dose coefficients mandated by the Italian legislation. Error propagation for the estimated intake and personal dose has been evaluated, starting from measurement statistics.

  6. Performance evaluation of domestic prototype dose area product meter SFT-1

    International Nuclear Information System (INIS)

    Lee, Ho Sun; Han, Seong Gyu; Roh, Young Roh; Lim, Hyun Jong; Kim, Jung Min; Kim, Jong Uk; Chae, Hyun Sik; Yoon, Yong Su

    2016-01-01

    The importance of radiation dose display of medical X-ray equipment was emphasized, while third edition of IEC(International Electrotechnical Commission) 60601 started to apply. The existing medical X-ray equipment selected a method for attaching the DAP(Dose Area Product) meter when the dose display. However, because the DAP meter was dependent on all of the income, And it did not yet produced in Korea. So, we received the support of Seoul R and BD Program(Grants No. C1152055) to produce DAP meter prototype of the Domestically technology. In this study, the performance of this prototype was evaluated by comparing the German company's product. Evaluation item was an electronic capture performance, radiation dose dependence, radiation quality dependence, energy transmittance, repeatability, light transmittance of 6 entries. And IEC 60580 was based on this evaluation. Evaluation results were electronic capture performance intrinsic error 9.5%, radiation dose dependence limits of variation 1%, repeatabilit y coefficient of variation 2%, energy transmittance 91% each assessment was passed. However radiation quality dependence limits of variation 29%, light transmittance 55% was less than acceptance criteria

  7. Evaluation of dose attenuation factor of armored car against radiation accidents

    International Nuclear Information System (INIS)

    Sato, Tatsuhiko; Fujii, Katsutoshi; Murayama, Takashi

    2002-03-01

    The Tokyo Fire Department developed an armored car against radiation accidents. The car is covered by lead shields for attenuating dose from gamma rays. Dose from neutrons also can be attenuated by pouring water into tanks attached to the surface of the car. However, dose attenuation factors of the radiation shields had been determined by an estimation of single-layer shield, and more precise evaluation of multi-layer shield was required. By request from the Tokyo Fire Department, a precise evaluation of the dose attenuation in multi-layer shield was carried out. The evaluation was made by a Monte Carlo radiation transport simulation code MCNP4B for the shields used in the front, side and back of the car. Three types of the radiation sources ( 252 Cf as a neutron source, 60 Co as a gamma ray source, and radiation source corresponding to the JCO criticality accident) were considered in the calculation. Benchmark experiments using neutron and gamma ray sources were also performed for ensuring the evaluation method. As a result, it was found out that doses of neutron and gamma ray were attenuated to approximately 10% and 25% by the thickest shield, respectively. These values were close to the ones which had already obtained by the estimation of single-layer shield. (author)

  8. Evaluation of patient radiation doses using DAP meter in interventional radiology procedures

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Sam [Dept. of Radiological Technology. Shingu University, Sungnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu Univeristy, Kyushu (Japan)

    2017-03-15

    The author investigated interventional radiology patient doses in several other countries, assessed accuracy of DAP meters embedded in intervention equipment in domestic country, conducted measurement of patient doses for 13 major interventional procedures with use of Dose Area Product(DAP) meters from 23 hospitals in Korea, and referred to 8,415 cases of domestic data related to interventional procedures by radiation exposure after evaluation the actual effective of dose reduction variables through phantom test. Finally, dose reference level for major interventional procedures was suggested. In this study, guidelines for patient doses were 237.7 Gy·cm{sup 2} in TACE, 17.3 Gy·cm{sup 2} in AVF, 114.1 Gy·cm{sup 2} in LE PTA and STENT, 188.5 Gy·cm{sup 2} in TFCA, 383.5 Gy·cm{sup 2} in Aneurysm Coil, 64.6 Gy·cm{sup 2} in PTBD, 64.6 Gy·cm{sup 2} in Biliary Stent, 22.4 Gy·cm{sup 2} in PCN, 4.3 Gy·cm{sup 2} in Hickman, 2.8 Gy·cm{sup 2} in Chemo-port, 4.4 Gy·cm{sup 2} in Perm-Cather, 17.1 Gy·cm{sup 2} in PCD, and 357.9 Gy·cm{sup 2} in Vis, EMB. Dose reference level acquired in this study is considered to be able to use as minimal guidelines for reducing patient dose in the interventional radiology procedures. For the changes and advances of materials and development of equipment and procedures in the interventional radiology procedures, further studies and monitoring are needed on dose reference level Korean DAP dose conversion factor for the domestic procedures.

  9. SU-E-J-07: IGRT Gently: Evaluating Imaging Dose in Phantoms of Different Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Morris, B; Duggar, W; Stanford, J; Yang, C [University of Mississippi Med. Center, Jackson, MS (United States)

    2015-06-15

    Purpose: IGRT imaging procedures have emerged as a common method of patient position verification in radiotherapy, though imaging dose is generally neglected in the treatment plan. Consequently, evaluating and optimizing the dose from these procedures is worthwhile. This process is especially important for children, who are more radiosensitive than adults. The aim of this work was to gain some understanding of the relative doses involved with various XVI-preset parameters for an “adult” and “child” phantom set, with the hopes that imaging dose for a child can be reduced. Methods: 32 and 16cm CTDI-phantoms were used as surrogates for adult and child torsos, respectively. Dose was measured in the central and peripheral chamber positions of the phantoms. CBCT scans were made for both phantoms using Elekta’s Chest-preset to establish a dose baseline. The child-phantom was then scanned using the Elekta Head and Neck (HN) preset. A modified HN-preset (named Peds Abd-pelvis) was also created with a doubled mAs to maintain a reduction in dose to the child-phantom (relative to the baseline), while providing clinically-usable image quality. Results: The baseline dose to the child-phantom from the Chest-preset was 310% that of the adult-phantom for the center chamber position and 150% at the periphery. An average dose reduction of 97% was obtained in the childphantom by switching from the Chest-preset to the HN-preset, while the Peds Abd-pelvis-preset similarly reduced the dose by an average of 92%. Conclusion: XVI-preset parameters significantly affect dose, and should be optimized to reduce dose, while ensuring clinically-usable image quality. Using a modified imaging preset (Peds Abd-pelvis-preset) greatly reduced the dose to the child-phantom compared to the dose for the Chest-preset for both the child and adult-phantoms. This outcome provides support for the development of child-specific protocols for IGRT imaging in pediatric patients.

  10. SU-E-J-07: IGRT Gently: Evaluating Imaging Dose in Phantoms of Different Sizes

    International Nuclear Information System (INIS)

    Morris, B; Duggar, W; Stanford, J; Yang, C

    2015-01-01

    Purpose: IGRT imaging procedures have emerged as a common method of patient position verification in radiotherapy, though imaging dose is generally neglected in the treatment plan. Consequently, evaluating and optimizing the dose from these procedures is worthwhile. This process is especially important for children, who are more radiosensitive than adults. The aim of this work was to gain some understanding of the relative doses involved with various XVI-preset parameters for an “adult” and “child” phantom set, with the hopes that imaging dose for a child can be reduced. Methods: 32 and 16cm CTDI-phantoms were used as surrogates for adult and child torsos, respectively. Dose was measured in the central and peripheral chamber positions of the phantoms. CBCT scans were made for both phantoms using Elekta’s Chest-preset to establish a dose baseline. The child-phantom was then scanned using the Elekta Head and Neck (HN) preset. A modified HN-preset (named Peds Abd-pelvis) was also created with a doubled mAs to maintain a reduction in dose to the child-phantom (relative to the baseline), while providing clinically-usable image quality. Results: The baseline dose to the child-phantom from the Chest-preset was 310% that of the adult-phantom for the center chamber position and 150% at the periphery. An average dose reduction of 97% was obtained in the childphantom by switching from the Chest-preset to the HN-preset, while the Peds Abd-pelvis-preset similarly reduced the dose by an average of 92%. Conclusion: XVI-preset parameters significantly affect dose, and should be optimized to reduce dose, while ensuring clinically-usable image quality. Using a modified imaging preset (Peds Abd-pelvis-preset) greatly reduced the dose to the child-phantom compared to the dose for the Chest-preset for both the child and adult-phantoms. This outcome provides support for the development of child-specific protocols for IGRT imaging in pediatric patients

  11. A γ dose distribution evaluation technique using the k-d tree for nearest neighbor searching

    International Nuclear Information System (INIS)

    Yuan Jiankui; Chen Weimin

    2010-01-01

    Purpose: The authors propose an algorithm based on the k-d tree for nearest neighbor searching to improve the γ calculation time for 2D and 3D dose distributions. Methods: The γ calculation method has been widely used for comparisons of dose distributions in clinical treatment plans and quality assurances. By specifying the acceptable dose and distance-to-agreement criteria, the method provides quantitative measurement of the agreement between the reference and evaluation dose distributions. The γ value indicates the acceptability. In regions where γ≤1, the predefined criterion is satisfied and thus the agreement is acceptable; otherwise, the agreement fails. Although the concept of the method is not complicated and a quick naieve implementation is straightforward, an efficient and robust implementation is not trivial. Recent algorithms based on exhaustive searching within a maximum radius, the geometric Euclidean distance, and the table lookup method have been proposed to improve the computational time for multidimensional dose distributions. Motivated by the fact that the least searching time for finding a nearest neighbor can be an O(log N) operation with a k-d tree, where N is the total number of the dose points, the authors propose an algorithm based on the k-d tree for the γ evaluation in this work. Results: In the experiment, the authors found that the average k-d tree construction time per reference point is O(log N), while the nearest neighbor searching time per evaluation point is proportional to O(N 1/k ), where k is between 2 and 3 for two-dimensional and three-dimensional dose distributions, respectively. Conclusions: Comparing with other algorithms such as exhaustive search and sorted list O(N), the k-d tree algorithm for γ evaluation is much more efficient.

  12. Controlled single-blind clinical evaluation of low-dose mammographic screen: film systems

    International Nuclear Information System (INIS)

    Sickles, E.A.; Genant, H.K.

    1979-01-01

    The ability of five low-dose mammographic screen-film systems to portray normal and abnormal breast structures was evaluated in parallel with a study of physical image properties. Single-blind evaluations of the visibility of normal breast architecture, mass lesions, and calcifications were made on the mammograms of 100 patients radiographed with each of the systems. There was increased noise and slightly poorer resolution of the faster recording systems, but there was no difference in final diagnostic impressions among the five systems. These results suggest that the faster systems will result in substantial dose reduction without sacrificing diagnostic accuracy

  13. Evaluation of the absorbed doses in conditions of external and internal contamination with radionuclides

    International Nuclear Information System (INIS)

    Milivojevic, K.; Stojanovic, D.; Markovic, P.

    1981-01-01

    In experimental conditions of contamination with radionuclides of the skin and skin injuries, an evaluation of the degree of local irradiation in decontamined region and doses absorbed in organs of selective accumulating was carried out by use of mathematical models and tissue-equivalent thermoluminescent dosemeters. The evaluation of the absorbed doses based on conception, that in adequate analyses of decontamination effect, as a most efficient medico-prophilactic measure from local and total irradiation, should be taken into account the total body burden of the penetrated radionuclide, selective accumulating in critical organs or tissues, as well as the residual radioactivity in decontaminated region. (author)

  14. A methodology for the evaluation of the collective dose from radioactivity in terrestrial food chains

    International Nuclear Information System (INIS)

    Simmonds, J.R.; Linsley, G.S.

    1980-02-01

    A methodology is described for the evaluation of the collective dose from radioactivity in the terrestrial food chains. It involves the use of an agricultural grid for Great Britain from which the geographical distribution of each of the main cereal, vegetable, fruit and animal products around any given point can be evaluated. A description is given of the procedure by which the grid was assembled. The use of the grid is demonstrated in an example in which the collective doses associated with the milk pathway to man following the routine discharge to air of iodine-131 are compared for two coastal sites in markedly different agricultural regions. (author)

  15. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    International Nuclear Information System (INIS)

    Han, Su Chul; Park, Seung Woo

    2017-01-01

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom

  16. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Han, Su Chul [Div. of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Seung Woo [Radilogcial and Medico-Oncological Sciences, University of Sciences and Technology, Daejeon (Korea, Republic of)

    2017-03-15

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom.

  17. Evaluation of doses in conventional radiology in the cities of Rio de Janeiro e Recife, Brazil

    International Nuclear Information System (INIS)

    Azevedo, Ana Cecilia P.; Osibote, Adelaja O.; Khoury, Helen J.

    2005-01-01

    This work is part of a program of evaluating doses in patients developed in several hospitals in the States of Rio de Janeiro and Pernambuco. We used the program DoseCal to evaluate the Input Skin Dose (DEP) and the Effective Dose (DE) in big public hospitals in the cities of Rio de Janeiro and Recife. It were included in the survey the doses of chest radiographs, cervical spine, lumbar spine, skull and pelvis in the projections AP, PA and LAT. To chest in PA the average value of DEP for the hospital A was 0.19 mGy. For to hospital B was 0.07 mGy. For the exam of the skull in PA the average value in A was 3.25 mGy and B of 0.49 mGy. With respect to radiological techniques might be noted that in most cases the hospital A used kilovoltage lower than in B and miliamperes higher. This can be one of the explanations for the difference of the values found for DEP and DE. The results showed significant discrepancies in values of doses as radiographic techniques when compared to the requirements established by the European Community for X-rays with image quality. This result is due to several factors: filtration, radiographic technique, professional technical experience and performance of radiographic equipment

  18. [Evaluation of an Experimental Production Wireless Dose Monitoring System for Radiation Exposure Management of Medical Staff].

    Science.gov (United States)

    Fujibuchi, Toshioh; Murazaki, Hiroo; Kuramoto, Taku; Umedzu, Yoshiyuki; Ishigaki, Yung

    2015-08-01

    Because of the more advanced and more complex procedures in interventional radiology, longer treatment times have become necessary. Therefore, it is important to determine the exposure doses received by operators and patients. The aim of our study was to evaluate an experimental production wireless dose monitoring system for pulse radiation in diagnostic X-ray. The energy, dose rate, and pulse fluoroscopy dependence were evaluated as the basic characteristics of this system for diagnostic X-ray using a fully digital fluoroscopy system. The error of 1 cm dose equivalent rate was less than 15% from 35.1 keV to 43.2 keV with energy correction using metal filter. It was possible to accurately measure the dose rate dependence of this system, which was highly linear until 100 μSv/h. This system showed a constant response to the pulse fluoroscopy. This system will become useful wireless dosimeter for the individual exposure management by improving the high dose rate and the energy characteristics.

  19. Radiation dose evaluation of dental cone beam computed tomography using an anthropomorphic adult head phantom

    Science.gov (United States)

    Wu, Jay; Shih, Cheng-Ting; Ho, Chang-hung; Liu, Yan-Lin; Chang, Yuan-Jen; Min Chao, Max; Hsu, Jui-Ting

    2014-11-01

    Dental cone beam computed tomography (CBCT) provides high-resolution tomographic images and has been gradually used in clinical practice. Thus, it is important to examine the amount of radiation dose resulting from dental CBCT examinations. In this study, we developed an in-house anthropomorphic adult head phantom to evaluate the level of effective dose. The anthropomorphic phantom was made of acrylic and filled with plaster to replace the bony tissue. The contour of the head was extracted from a set of adult computed tomography (CT) images. Different combinations of the scanning parameters of CBCT were applied. Thermoluminescent dosimeters (TLDs) were used to measure the absorbed doses at 19 locations in the head and neck regions. The effective doses measured using the proposed phantom at 65, 75, and 85 kVp in the D-mode were 72.23, 100.31, and 134.29 μSv, respectively. In the I-mode, the effective doses were 108.24, 190.99, and 246.48 μSv, respectively. The maximum percent error between the doses measured by the proposed phantom and the Rando phantom was l4.90%. Therefore, the proposed anthropomorphic adult head phantom is applicable for assessing the radiation dose resulting from clinical dental CBCT.

  20. Evaluation of radiation dose in pediatric head CT examination: a phantom study

    Science.gov (United States)

    Norhasrina Nik Din, Nik; Zainon, Rafidah; Rahman, Ahmad Taufek Abdul

    2018-01-01

    The aim of this study was to evaluate the radiation dose in pediatric head Computed Tomography examination. It was reported that decreasing tube voltage in CT examination can reduce the dose to patients significantly. A head phantom was scanned with dual-energy CT at 80 kV and 120 kV. The tube current was set using automatic exposure control mode and manual setting. The pitch was adjusted to 1.4, 1.45 and 1.5 while the slice thickness was set at 5 mm. The dose was measured based on CT Dose Index (CTDI). Results from this study have shown that the image noise increases substantially with low tube voltage. The average dose was 2.60 mGy at CT imaging parameters of 80 kV and 10 - 30 mAs. The dose increases up to 17.19 mGy when the CT tube voltage increases to 120 kV. With the reduction of tube voltage from 120 kV to 80 kV, the radiation dose can be reduced by 12.1% to 15.1% without degradation of contrast-to-noise ratio.

  1. Accuracy of neutron dose evaluation in the area monitoring for LHD experiments

    CERN Document Server

    Yamanishi, H; Uda, T; Tanahashi, S; Saitou, M; Handa, H

    2000-01-01

    The error in the evaluation of neutron dose during calculation of the neutron field around the large helical device (LHD) in D-D operation is discussed. The expected neutron dose at each monitoring point was derived from the dose conversion factor and neutron fluence data, which was calculated with the radiation transport code DOT-3.5. In contrast, the detected dose at the neutron counter was obtained from the fluence data and the detector response given by calculation with MCNP-4b. The neutron counter used in these calculations consisted of a helium-3 proportional counter with a cylindrical polyethylene moderator. According to the results of the calculations, the ratio of the detected dose to the expected dose was found to lie in the range 1.0-3.0 on the outdoor monitoring points. Since the response of a single neutron counter may lead to inconsistencies in the dose conversion factor, we attempted to minimize these inconsistencies by using a pair of counters with moderators of different thickness. The ratio ...

  2. Evaluation of GafChromic EBT prototype B for external beam dose verification

    International Nuclear Information System (INIS)

    Todorovic, M.; Fischer, M.; Cremers, F.; Thom, E.; Schmidt, R.

    2006-01-01

    The capability of the new GafChromic EBT prototype B for external beam dose verification is investigated in this paper. First the general characteristics of this film (dose response, postirradiation coloration, influence of calibration field size) were derived using a flat-bed scanner. In the dose range from 0.1 to 8 Gy, the sensitivity of the EBT prototype B film is ten times higher than the response of the GafChromic HS, which so far was the GafChromic film with the highest sensitivity. Compared with the Kodak EDR2 film, the response of the EBT is higher by a factor of 3 in the dose range from 0.1 to 8 Gy. The GafChromic EBT almost does not show a temporal growth of the optical density and there is no influence of the chosen calibration field size on the dose response curve obtained from this data. A MatLab program was written to evaluate the two-dimensional dose distributions from treatment planning systems and GafChromic EBT film measurements. Verification of external beam therapy (SRT, IMRT) using the above-mentioned approach resulted in very small differences between the planned and the applied dose. The GafChromic EBT prototype B together with the flat-bed scanner and MatLab is a successful approach for making the advantages of the GafChromic films applicable for verification of external beam therapy

  3. Radiological Evaluation of the effects of varied doses of Celecoxib on fracture healing in dogs

    Directory of Open Access Journals (Sweden)

    Edwin Aihanuwa Uwagie-Ero and Rapheal Chukwujekwu Kene

    2011-04-01

    Full Text Available To determine if Cyclooxygenase -2 (COX-2 functions in fracture healing, 10 dogs were treated with COX-2-selective nonsteroidal anti-inflammatory drugs (Celecoxib to reduce and stop COX-2-dependent prostaglandin production. Radiographic testing evaluation determined that fracture healing was not affected in dogs treated with a low dose of COX-2-selective NSAIDs (celecoxib and delayed union was observed in dogs treated with a high dose of COX-2-selective NSAIDs (celecoxib. Celecoxib dose of 5 mg/kg/day did not affect fracture callus formed in the study group and did not cause a significant increase in the proportion of delayed unions, however, at a dose of 10 mg/kg/day it reduced the rate of fracture callus formation and significantly increased the proportion of delayed unions for dogs in the group. [Veterinary World 2011; 4(2.000: 75-76

  4. Statistical evaluation of the dose-distribution charts of the National Computerized Irradiation Planning Network

    International Nuclear Information System (INIS)

    Varjas, Geza; Jozsef, Gabor; Gyenes, Gyoergy; Petranyi, Julia; Bozoky, Laszlo; Pataki, Gezane

    1985-01-01

    The establishment of the National Computerized Irradiation Planning Network allowed to perform the statistical evaluation presented in this report. During the first 5 years 13389 dose-distribution charts were calculated for the treatment of 5320 patients, i.e. in average, 2,5 dose-distribution chart-variants per patient. This number practically did not change in the last 4 years. The irradiation plan of certain tumour localizations was performed on the basis of the calculation of, in average, 1.6-3.0 dose-distribution charts. Recently, radiation procedures assuring optimal dose-distribution, such as the use of moving fields, and two- or three-irradiation fields, are gaining grounds. (author)

  5. Evaluation of the uncertainties in the TLD radiosurgery postal dose system

    Science.gov (United States)

    Campos, L. T.; Leite, S. P.; de Almeida, C. E. V.; Magalhães, L. A. G.

    2018-03-01

    Stereotactic radiosurgery is a single-fraction radiation therapy procedure for treating intracranial lesions using a stereotactic apparatus and multiple narrow beams delivered through noncoplanar isocentric arcs. To guarantee a high quality standard, a comprehensive Quality Assurance programme is extremely important to ensure that the measured dose is consistent with the tolerance considered to improve treatment quality. The Radiological Science Laboratory operates a postal audit programme in SRT and SRS. The purpose of the programme is to verify the target localization accuracy in known geometry and the dosimetric conditions of the TPS. The programme works in such a way those thermoluminescence dosimeters, consisting of LiF chips, are sent to the centre where they are to be irradiated to a certain dose. The TLD are then returned, where they are evaluated and the absorbed dose is obtained from TLDs readings. The aim of the present work is estimate the uncertainties in the process of dose determination, using experimental data.

  6. Evaluation of Patient Radiation Dose during Cardiac Interventional Procedures: What Is the Most Effective Method?

    International Nuclear Information System (INIS)

    Chida, K.; Saito, H.; Ishibashi, T.; Zuguchi, M.; Kagaya, Y.; Takahashi, S.

    2009-01-01

    Cardiac interventional radiology has lower risks than surgical procedures. This is despite the fact that radiation doses from cardiac intervention procedures are the highest of any commonly performed general X-ray examination. Maximum radiation skin doses (MSDs) should be determined to avoid radiation-associated skin injuries in patients undergoing cardiac intervention procedures. However, real-time evaluation of MSD is unavailable for many cardiac intervention procedures. This review describes methods of determining MSD during cardiac intervention procedures. Currently, in most cardiac intervention procedures, real-time measuring of MSD is not feasible. Thus, we recommend that physicians record the patient's total entrance skin dose, such as the dose at the interventional reference point when it can be monitored, in order to estimate MSD in intervention procedures

  7. Curie temperature and magnetic phase transition of nanostructured ultrathin Fe/GaAs (001). Size dependence and relevance of dipolar coupling

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Roland

    2009-07-01

    In the present work the impact of lateral patterning of ultrathin ferromagnetic films down to the nanometer range on the magnetic phase transition has been investigated. In this respect on the one hand a size effect on the Curie temperature and, referring to that, the relevance of dipolar coupling were a matter of particular interest. On the other hand the characteristics of the critical behavior itself, becoming apparent by the accurate evaluation of the curvature shape of the magnetization as a function of temperature at T{sub c}, were analyzed with regard to potential and expected size effects. The investigation of similar nanostructures with respect to an effect on Curie temperature respectively phase transition may draw up a correlation. Therefore more than hundred samples were fabricated for this work extensively by means of MBE (Molecular Beam Epitaxy) and ESL (Electron Beam Epitaxy) methods, measured by MOKE (Magneto-Optical Kerr Effect) technique and systematically evaluated. (orig.)

  8. Evaluation of six TPS algorithms in computing entrance and exit doses

    Science.gov (United States)

    Metwaly, Mohamed; Glegg, Martin; Baggarley, Shaun P.; Elliott, Alex

    2014-01-01

    Entrance and exit doses are commonly measured in in vivo dosimetry for comparison with expected values, usually generated by the treatment planning system (TPS), to verify accuracy of treatment delivery. This report aims to evaluate the accuracy of six TPS algorithms in computing entrance and exit doses for a 6 MV beam. The algorithms tested were: pencil beam convolution (Eclipse PBC), analytical anisotropic algorithm (Eclipse AAA), AcurosXB (Eclipse AXB), FFT convolution (XiO Convolution), multigrid superposition (XiO Superposition), and Monte Carlo photon (Monaco MC). Measurements with ionization chamber (IC) and diode detector in water phantoms were used as a reference. Comparisons were done in terms of central axis point dose, 1D relative profiles, and 2D absolute gamma analysis. Entrance doses computed by all TPS algorithms agreed to within 2% of the measured values. Exit doses computed by XiO Convolution, XiO Superposition, Eclipse AXB, and Monaco MC agreed with the IC measured doses to within 2%‐3%. Meanwhile, Eclipse PBC and Eclipse AAA computed exit doses were higher than the IC measured doses by up to 5.3% and 4.8%, respectively. Both algorithms assume that full backscatter exists even at the exit level, leading to an overestimation of exit doses. Despite good agreements at the central axis for Eclipse AXB and Monaco MC, 1D relative comparisons showed profiles mismatched at depths beyond 11.5 cm. Overall, the 2D absolute gamma (3%/3 mm) pass rates were better for Monaco MC, while Eclipse AXB failed mostly at the outer 20% of the field area. The findings of this study serve as a useful baseline for the implementation of entrance and exit in vivo dosimetry in clinical departments utilizing any of these six common TPS algorithms for reference comparison. PACS numbers: 87.55.‐x, 87.55.D‐, 87.55.N‐, 87.53.Bn PMID:24892349

  9. Evaluation of radiation dose to pediatric patients during certain special procedures

    International Nuclear Information System (INIS)

    Sulieman, A.; Alzimami, K.; Elhag, B.; Babikir, E.; Alsafi, K.

    2014-01-01

    This study was intended to measure pediatric entrance surface air kerma (ESAK) and effective dose during micturating cystourethrography (MCU), intravenous urography (IVU) and barium studies (barium meal, enema, and swallow) and to propose a local diagnostic reference level (DRL). ESAK was measured for patients using calibrated thermoluminescent dosimeters (TLDs, GR200A). Effective doses (E) were calculated using the National Radiological Protection Board (NRPB) software. A total of 236 special pediatric procedures were investigated. 21.7% of the sample comprised barium procedures, 18.6% were MCU procedures while 59.5% of the sample were IVU procedures. The mean ESAK measurements (mGy) were 2.1±0.8, 3.0±23 and 1.2±0.2 for barium meal, enema and swallow in the same order. The mean patient dose for IVU procedures was 12.4±8.7 mGy per procedure and the mean patient dose per MCU procedure was 5.8±7 mGy. Local DRLs were proposed for all procedures. The patient doses in this study are within the reported values, suggesting that pediatric patients are adequately protected. - Highlights: • Pediatric radiation dose has been evaluated for three of the most common fluoroscopic procedures. • Radiation doses were measured using calibrated TLD GR200A. • Pediatric patients of concern and ESAK doses showed large variations. • The patient doses in this study are within the reported studies suggesting that the pediatric patients are adequately protected

  10. The evaluation the magnitude radiation exposure dose rate in digital radiography room design

    Science.gov (United States)

    Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

    2017-12-01

    This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

  11. Measurement and evaluation of personal radiation dose during 18F-FDG PET imaging

    International Nuclear Information System (INIS)

    Lu Ning; Wang Jing; Qiao Hongqing; Deng Jinglan; Li Guoquan; Zhou Yi

    2004-01-01

    Objective: To measure and evaluate the personal radiation dose for medical staff and patient accompanying persons in PET imaging, in order to offer the reference data for clinical radiation protection. Methods: Analysis of γ-ray radiation dose rate was performed on 30 medical staff members by using radiation dose meter during each medical procedure in injection room and scanning room , and the instantaneous, 1 and 2 h dose rate at 0.1, 0.5, 1.0 and 2.0 m from the mid-thorax of the patient received injection of the isotope were also measured. Then the mean dose per medical procedure per person and the assuming annual dose at different working sites were all calculated. Results: The mean personal doses per procedure were: left hand (30.0 ± 8.0) μSv, right hand (6.0 ± 1.5) μSv, whole-body (0.5 ± 0.1) μSv for syringe preparation; hand (3.00 ± 0.75) μSv, whole-body (1.27 ± 0.20) μSv for injection; (9.9 ± 1.4) μSv for imaging operation; (310 ± 91) μSv for close contact accompanying persons. Annual dose for staff members working in different sites were: left hand (16.63 ± 4.41) mSv, right hand (6.45 ± 1.23) mSv, whole-body (1.18 ± 0.15) mSv in the injection room; whole-body (4.99 ± 0.70) mSv in the imaging room. Conclusion: Under the normal operational conditions, the dose received by staff members and accompanying persons do not exceed the annual limit for professional and non-professional persons that has published as GuoBiao safe standard (GBSS)

  12. Correction for FDG PET dose extravasations: Monte Carlo validation and quantitative evaluation of patient studies

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Rodríguez, Jesús, E-mail: jesus.silva.rodriguez@sergas.es; Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Santiago de Compostela, Galicia (Spain); Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Sánchez, Manuel; Mosquera, Javier; Luna-Vega, Víctor [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Cortés, Julia; Garrido, Miguel [Servicio de Medicina Nuclear, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia, Spain and Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Pombar, Miguel [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia (Spain); Ruibal, Álvaro [Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Fundación Tejerina, 28003, Madrid (Spain)

    2014-05-15

    Purpose: Current procedure guidelines for whole body [18F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) state that studies with visible dose extravasations should be rejected for quantification protocols. Our work is focused on the development and validation of methods for estimating extravasated doses in order to correct standard uptake value (SUV) values for this effect in clinical routine. Methods: One thousand three hundred sixty-seven consecutive whole body FDG-PET studies were visually inspected looking for extravasation cases. Two methods for estimating the extravasated dose were proposed and validated in different scenarios using Monte Carlo simulations. All visible extravasations were retrospectively evaluated using a manual ROI based method. In addition, the 50 patients with higher extravasated doses were also evaluated using a threshold-based method. Results: Simulation studies showed that the proposed methods for estimating extravasated doses allow us to compensate the impact of extravasations on SUV values with an error below 5%. The quantitative evaluation of patient studies revealed that paravenous injection is a relatively frequent effect (18%) with a small fraction of patients presenting considerable extravasations ranging from 1% to a maximum of 22% of the injected dose. A criterion based on the extravasated volume and maximum concentration was established in order to identify this fraction of patients that might be corrected for paravenous injection effect. Conclusions: The authors propose the use of a manual ROI based method for estimating the effectively administered FDG dose and then correct SUV quantification in those patients fulfilling the proposed criterion.

  13. Application of dose evaluation of the MCNP code for interim spent fuel cask storage facility

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Iimoto, Takeshi; Ishikawa, Satoshi; Tsuboi, Takafumi; Teramura, Masahiro; Okamura, Tomomi; Narumiya, Yoshiyuki

    2007-01-01

    The interim storage facility for spent fuel metallic cask is designed as a concrete building structure with air inlet and outlet for circulating the natural cooling. The feature of the interim storage facility is big capacity of spent fuel at several thousands MTU and restricted site usage. It is important to evaluate realistic dose rate in shielding design of the interim storage facility, therefore the three-dimensional continuous-energy Monte Carlo radiation transport code MCNP that exactly treating the complicated geometry was applied. The validation of dose evaluation for interim storage facility by MCNP code were performed by three kinds of neutron shielding benchmark experiments; cask shadow shielding experiment, duct streaming experiment and concrete deep penetration experiment. Dose rate distributions at each benchmark were measured and compared with the calculated results. The comparison showed a good consistency between calculation and experiment results. (author)

  14. Evaluation of the dose committed as based on direct measurements with the Whole Body Counter

    International Nuclear Information System (INIS)

    Meladani, C.; Castellani, C.M.; Battisti, P.; Tarroni, G.

    1989-01-01

    During normal working activities or in accidental situations, when the introduction of radioactive gamma emitters is non-negligible amount, accurate determination of effective committed dose equivalent based on direct measurements of the internal contamination cannot be avoided. Internal contamination measurements carried out by Whole Body Counter and the application of dosimetric and metabolic models as proposed by ICRP Publication 30 allow the intakes and committed dose equivalents to be evaluated. This paper presents the evaluation methodologies of committed dose equivalent both for istantaneous and extended contaminations. Furthermore, some advice about useful, opportune modes and time uncertainties due to the application of generalized models to particular situations, are also reported. On the basis of the Chernobyl experience, the general criteria for the chice and size of homogeneous groups of individuals to be measured, are finally submitted with a view to collecting the necessary radiation protection information concerning contamination of a part or a whole population

  15. A consideration on internal dose evaluation and intervention based on a surface contamination concept

    International Nuclear Information System (INIS)

    Yasuda, H.

    1997-01-01

    Long-term radiation doses received by the inhabitants after the Chernobyl accident have been evaluated according to the surface contamination levels on the ground surface. The health effects have also been discussed by comparison between the surface-contaminated area and the uncontaminated control area. Selected protective measures were carried out in accordance with the contamination level of surface soil. These have been based on the 'surface contamination concept' which assumes that the radiation risk to inhabitants is proportional to the level of ground-surface contamination. The observations collected in regions around Chernobyl, however, show that the internal radiation doses to the inhabitants poorly correlate with the surface contamination level. This fact poses a question on the suitability of dose evaluations and interventions based on this concept

  16. Four-dimensional dose evaluation using deformable image registration in radiotherapy for liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hoon Jung, Sang; Min Yoon, Sang; Ho Park, Sung; Cho, Byungchul; Won Park, Jae; Jung, Jinhong; Park, Jin-hong; Hoon Kim, Jong; Do Ahn, Seung [Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736 (Korea, Republic of)

    2013-01-15

    Purpose: In order to evaluate the dosimetric impact of respiratory motion on the dose delivered to the target volume and critical organs during free-breathing radiotherapy, a four-dimensional dose was evaluated using deformable image registration (DIR). Methods: Four-dimensional computed tomography (4DCT) images were acquired for 11 patients who were treated for liver cancer. Internal target volume-based treatment planning and dose calculation (3D dose) were performed using the end-exhalation phase images. The four-dimensional dose (4D dose) was calculated based on DIR of all phase images from 4DCT to the planned image. Dosimetric parameters from the 4D dose, were calculated and compared with those from the 3D dose. Results: There was no significant change of the dosimetric parameters for gross tumor volume (p > 0.05). The increase D{sub mean} and generalized equivalent uniform dose (gEUD) for liver were by 3.1%{+-} 3.3% (p= 0.003) and 2.8%{+-} 3.3% (p= 0.008), respectively, and for duodenum, they were decreased by 15.7%{+-} 11.2% (p= 0.003) and 15.1%{+-} 11.0% (p= 0.003), respectively. The D{sub max} and gEUD for stomach was decreased by 5.3%{+-} 5.8% (p= 0.003) and 9.7%{+-} 8.7% (p= 0.003), respectively. The D{sub max} and gEUD for right kidney was decreased by 11.2%{+-} 16.2% (p= 0.003) and 14.9%{+-} 16.8% (p= 0.005), respectively. For left kidney, D{sub max} and gEUD were decreased by 11.4%{+-} 11.0% (p= 0.003) and 12.8%{+-} 12.1% (p= 0.005), respectively. The NTCP values for duodenum and stomach were decreased by 8.4%{+-} 5.8% (p= 0.003) and 17.2%{+-} 13.7% (p= 0.003), respectively. Conclusions: The four-dimensional dose with a more realistic dose calculation accounting for respiratory motion revealed no significant difference in target coverage and potentially significant change in the physical and biological dosimetric parameters in normal organs during free-breathing treatment.

  17. The evaluation of lens absorbed dose according to the optimold for whole brain radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong Mo; Park, Byoung Suk; Ahn, Jong Ho; Song, Ki Won [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    In the current whole brain Radiation Therapy, Optimold was used to immobilize the head. However, skin dose was increased about 22% due to the scattering radiation by the Optimold. Since the minimum dose causing cataracts was 2 Gy, it could be seen that the effects were large especially on the lens. Therefore, in the whole brain Radiation Therapy, it was to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part. In order to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part, the Optimold mask was made up to 5 mm bolus on the part of the eye lens in the human model phantom (Anderson Rando Phantom, USA). In the practice treatment, to measure the lens dose, the simulation therapy was processed by placing the GafChromic EBT3 film under bolus, and after the treatment plan was set up through the treatment planning system (Pinnacle, PHILIPS, USA), the treatments were measured repeatedly three times in the same way. After removing the Optimold mask in the eyeball part, it was measured in the same way as above. After scanning the film and measuring the dose by using the Digital Flatbed Scanner (Expression 10000XL, EPSON, USA), the doses were compared and evaluated according to the presence of Optimold mask in the eyeball part. When there was the Optimold mask in the eyeball part, it was measured at 10.2cGy ± 1.5 in the simulation therapy, and at 24.8cGy ± 2.7 in the treatment, and when the Optimold mask was removed in the eye part, it was measured at 12.9cGy ± 2.2 in the simulation therapy, and at 17.6cGy ± 1.5 in the treatment. In case of removing the Optimold mask in the eyeball part, the dose was increased approximately 3cGy in the simulation therapy and was reduced approximately 7cGy in the treatment in comparison to the case that the Optimold mask was not removed. During the whole treatment, since the lens absorbed dose was reduced about 27%, the chance to cause

  18. The evaluation of lens absorbed dose according to the optimold for whole brain radiation therapy

    International Nuclear Information System (INIS)

    Yang, Yong Mo; Park, Byoung Suk; Ahn, Jong Ho; Song, Ki Won

    2014-01-01

    In the current whole brain Radiation Therapy, Optimold was used to immobilize the head. However, skin dose was increased about 22% due to the scattering radiation by the Optimold. Since the minimum dose causing cataracts was 2 Gy, it could be seen that the effects were large especially on the lens. Therefore, in the whole brain Radiation Therapy, it was to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part. In order to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part, the Optimold mask was made up to 5 mm bolus on the part of the eye lens in the human model phantom (Anderson Rando Phantom, USA). In the practice treatment, to measure the lens dose, the simulation therapy was processed by placing the GafChromic EBT3 film under bolus, and after the treatment plan was set up through the treatment planning system (Pinnacle, PHILIPS, USA), the treatments were measured repeatedly three times in the same way. After removing the Optimold mask in the eyeball part, it was measured in the same way as above. After scanning the film and measuring the dose by using the Digital Flatbed Scanner (Expression 10000XL, EPSON, USA), the doses were compared and evaluated according to the presence of Optimold mask in the eyeball part. When there was the Optimold mask in the eyeball part, it was measured at 10.2cGy ± 1.5 in the simulation therapy, and at 24.8cGy ± 2.7 in the treatment, and when the Optimold mask was removed in the eye part, it was measured at 12.9cGy ± 2.2 in the simulation therapy, and at 17.6cGy ± 1.5 in the treatment. In case of removing the Optimold mask in the eyeball part, the dose was increased approximately 3cGy in the simulation therapy and was reduced approximately 7cGy in the treatment in comparison to the case that the Optimold mask was not removed. During the whole treatment, since the lens absorbed dose was reduced about 27%, the chance to cause

  19. Aerosol particle size distribution in building and caves: impact to the radon-related dose evaluation

    International Nuclear Information System (INIS)

    Berka, Z.; Thinova, L.; Brandejsova, E.; Zdimal, V.; Fronka, A.; Milka, D.

    2004-01-01

    The results of evaluation of the aerosol particle size spectra observed in the Bozkov cave are presented and compared with the spectra observed in residential areas. The radon-to-dose conversion factor is discussed, as is the correction factor referred to as the cave factor. (P.A.)

  20. Statistics of meteorology for dose evaluation of crews of nuclear ship

    International Nuclear Information System (INIS)

    Imai, Kazuhiko; Chino, Masamichi

    1981-01-01

    For the purpose of the dose evaluation of crews of a nuclear ship, the statistics of wind speed and direction relative to the ship is discussed, using wind data which are reported from ships crusing sea around Japan Island. The analysis on the data shows that the occurrence frequency of wind speed can be fitted with the γ-distribution having parameter p around 3 and wind direction frequency can be treated as a uniform distribution. Using these distributions and taking the ship speed u 3 and the long-term mean speed of natural wind anti u as constant parameters, frequency distribution of wind speed and direction relative to the ship was calculated and statistical quantities necessary for dose evaluation were obtained in the way similar to the procedure for reactor sites on land. The 97% value of wind speed u 97 , which should be used in the dose evaluation for accidental releases may give conservative doses, if it is evaluated as follows, u 97 = 0.64 u sub(s) in the cases u sub(s) > anti u, and u 97 = 0.86 anti u in the cases u sub(s) < anti u including u sub(s) = 0. (author)

  1. Surface membrane based bladder registration for evaluation of accumulated dose during brachytherapy in cervical cancer

    DEFF Research Database (Denmark)

    Noe, Karsten Østergaard; Tanderup, Kari; Sørensen, Thomas Sangild

    2011-01-01

    of the fixed surface. Optional landmark based matches can be included in the suggested iterative solver. The technique is demonstrated for bladder registration in brachytherapy treatment evaluation of cervical cancer. It holds promise to better estimate the accumulated but unintentional dose delivered...

  2. Evaluation of doses received by pediatric and adult patients undergoing to CT exams

    International Nuclear Information System (INIS)

    Lavie, Maria F. Jimenez; Tejeda, Adalberto Machado; Otano, Anisia; Zuniga, Dora Maya; Perdomo, Jorge Hing; Rodriguez, Gustavo Guadarrama

    2013-01-01

    This paper aims to evaluated the dose to adult and pediatric patients due to the execution of tests CT scan of head, chest and abdomen, as well as establish a comparative analysis between these results and protocols involving employees to begin a process optimization in the practice

  3. Evaluation of dose to skin surface contamination in the factory Juzbado of fuel elements

    International Nuclear Information System (INIS)

    Ortiz Trujillo, D.; Agustin Perez Fonseca, A.; Alejandro Fuentes, A.

    2013-01-01

    The aim of this work is previously set a simple calculation methodology applicable to the boundary conditions surrounding the environment where skin contamination may have occurred so that you can evaluate in a simple and fast way the dose that the worker is receiving while enduring such pollution. (Author)

  4. Using the Concept of "Population Dose" in Planning and Evaluating Community-Level Obesity Prevention Initiatives

    Science.gov (United States)

    Cheadle, Allen; Schwartz, Pamela M.; Rauzon, Suzanne; Bourcier, Emily; Senter, Sandra; Spring, Rebecca; Beery, William L.

    2013-01-01

    When planning and evaluating community-level initiatives focused on policy and environment change, it is useful to have estimates of the impact on behavioral outcomes of particular strategies (e.g., building a new walking trail to promote physical activity). We have created a measure of estimated strategy-level impact--"population dose"--based on…

  5. Dosimetric evaluation of the OneDoseTM MOSFET for measuring kilovoltage imaging dose from image-guided radiotherapy procedures.

    Science.gov (United States)

    Ding, George X; Coffey, Charles W

    2010-09-01

    The purpose of this study is to investigate the feasibility of using a single-use dosimeter, OneDose MOSFET designed for in vivo patient dosimetry, for measuring the radiation dose from kilovoltage (kV) x rays resulting from image-guided procedures. The OneDose MOSFET dosimeters were precalibrated by the manufacturer using Co-60 beams. Their energy response and characteristics for kV x rays were investigated by using an ionization chamber, in which the air-kerma calibration factors were obtained from an Accredited Dosimetry Calibration Laboratory (ADCL). The dosimetric properties have been tested for typical kV beams used in image-guided radiation therapy (IGRT). The direct dose reading from the OneDose system needs to be multiplied by a correction factor ranging from 0.30 to 0.35 for kilovoltage x rays ranging from 50 to 125 kVp, respectively. In addition to energy response, the OneDose dosimeter has up to a 20% reduced sensitivity for beams (70-125 kVp) incident from the back of the OneDose detector. The uncertainty in measuring dose resulting from a kilovoltage beam used in IGRT is approximately 20%; this uncertainty is mainly due to the sensitivity dependence of the incident beam direction relative to the OneDose detector. The ease of use may allow the dosimeter to be suitable for estimating the dose resulting from image-guided procedures.

  6. A spatially encoded dose difference maximal intensity projection map for patient dose evaluation: A new first line patient quality assurance tool

    Energy Technology Data Exchange (ETDEWEB)

    Hu Weigang; Graff, Pierre; Boettger, Thomas; Pouliot, Jean [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California 94143 (United States); and others

    2011-04-15

    Purpose: To develop a spatially encoded dose difference maximal intensity projection (DD-MIP) as an online patient dose evaluation tool for visualizing the dose differences between the planning dose and dose on the treatment day. Methods: Megavoltage cone-beam CT (MVCBCT) images acquired on the treatment day are used for generating the dose difference index. Each index is represented by different colors for underdose, acceptable, and overdose regions. A maximal intensity projection (MIP) algorithm is developed to compress all the information of an arbitrary 3D dose difference index into a 2D DD-MIP image. In such an algorithm, a distance transformation is generated based on the planning CT. Then, two new volumes representing the overdose and underdose regions of the dose difference index are encoded with the distance transformation map. The distance-encoded indices of each volume are normalized using the skin distance obtained on the planning CT. After that, two MIPs are generated based on the underdose and overdose volumes with green-to-blue and green-to-red lookup tables, respectively. Finally, the two MIPs are merged with an appropriate transparency level and rendered in planning CT images. Results: The spatially encoded DD-MIP was implemented in a dose-guided radiotherapy prototype and tested on 33 MVCBCT images from six patients. The user can easily establish the threshold for the overdose and underdose. A 3% difference between the treatment and planning dose was used as the threshold in the study; hence, the DD-MIP shows red or blue color for the dose difference >3% or {<=}3%, respectively. With such a method, the overdose and underdose regions can be visualized and distinguished without being overshadowed by superficial dose differences. Conclusions: A DD-MIP algorithm was developed that compresses information from 3D into a single or two orthogonal projections while hinting the user whether the dose difference is on the skin surface or deeper.

  7. A spatially encoded dose difference maximal intensity projection map for patient dose evaluation: a new first line patient quality assurance tool.

    Science.gov (United States)

    Hu, Weigang; Graff, Pierre; Boettger, Thomas; Pouliot, Jean

    2011-04-01

    To develop a spatially encoded dose difference maximal intensity projection (DD-MIP) as an online patient dose evaluation tool for visualizing the dose differences between the planning dose and dose on the treatment day. Megavoltage cone-beam CT (MVCBCT) images acquired on the treatment day are used for generating the dose difference index. Each index is represented by different colors for underdose, acceptable, and overdose regions. A maximal intensity projection (MIP) algorithm is developed to compress all the information of an arbitrary 3D dose difference index into a 2D DD-MIP image. In such an algorithm, a distance transformation is generated based on the planning CT. Then, two new volumes representing the overdose and underdose regions of the dose difference index are encoded with the distance transformation map. The distance-encoded indices of each volume are normalized using the skin distance obtained on the planning CT. After that, two MIPs are generated based on the underdose and overdose volumes with green-to-blue and green-to-red lookup tables, respectively. Finally, the two MIPs are merged with an appropriate transparency level and rendered in planning CT images. The spatially encoded DD-MIP was implemented in a dose-guided radiotherapy prototype and tested on 33 MVCBCT images from six patients. The user can easily establish the threshold for the overdose and underdose. A 3% difference between the treatment and planning dose was used as the threshold in the study; hence, the DD-MIP shows red or blue color for the dose difference > 3% or < or = 3%, respectively. With such a method, the overdose and underdose regions can be visualized and distinguished without being overshadowed by superficial dose differences. A DD-MIP algorithm was developed that compresses information from 3D into a single or two orthogonal projections while hinting the user whether the dose difference is on the skin surface or deeper.

  8. Dose response evaluation of a low-density normoxic polymer gel dosimeter using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Haraldsson, P [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Department of Radiation Physics, Finsen Centre, Copenhagen University Hospital, DK-2100 Copenhagen (Denmark); Karlsson, A [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Wieslander, E [Medical Radiation Physics, Department of Clinical Sciences, Lund University Hospital, SE-221 85 Lund (Sweden); Gustavsson, H [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Baeck, S A J [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden)

    2006-02-21

    A low-density ({approx}0.6 g cm{sup -3}) normoxic polymer gel, containing the antioxidant tetrakis (hydroxymethyl) phosponium (THP), has been investigated with respect to basic absorbed dose response characteristics. The low density was obtained by mixing the gel with expanded polystyrene spheres. The depth dose data for 6 and 18 MV photons were compared with Monte Carlo calculations. A large volume phantom was irradiated in order to study the 3D dose distribution from a 6 MV field. Evaluation of the gel was carried out using magnetic resonance imaging. An approximately linear response was obtained for 1/T2 versus dose in the dose range of 2 to 8 Gy. A small decrease in the dose response was observed for increasing concentrations of THP. A good agreement between measured and Monte Carlo calculated data was obained, both for test tubes and the larger 3D phantom. It was shown that a normoxic polymer gel with a reduced density could be obtained by adding expanded polystyrene spheres. In order to get reliable results, it is very important to have a uniform distribution of the gel and expanded polystyrene spheres in the phantom volume.

  9. Dose response evaluation of a low-density normoxic polymer gel dosimeter using MRI

    Science.gov (United States)

    Haraldsson, P.; Karlsson, A.; Wieslander, E.; Gustavsson, H.; Bäck, S. Å. J.

    2006-02-01

    A low-density (~0.6 g cm-3) normoxic polymer gel, containing the antioxidant tetrakis (hydroxymethyl) phosponium (THP), has been investigated with respect to basic absorbed dose response characteristics. The low density was obtained by mixing the gel with expanded polystyrene spheres. The depth dose data for 6 and 18 MV photons were compared with Monte Carlo calculations. A large volume phantom was irradiated in order to study the 3D dose distribution from a 6 MV field. Evaluation of the gel was carried out using magnetic resonance imaging. An approximately linear response was obtained for 1/T2 versus dose in the dose range of 2 to 8 Gy. A small decrease in the dose response was observed for increasing concentrations of THP. A good agreement between measured and Monte Carlo calculated data was obained, both for test tubes and the larger 3D phantom. It was shown that a normoxic polymer gel with a reduced density could be obtained by adding expanded polystyrene spheres. In order to get reliable results, it is very important to have a uniform distribution of the gel and expanded polystyrene spheres in the phantom volume.

  10. Overview of internal dose evaluation in the radiopharmaceutical production plant at IPEN

    International Nuclear Information System (INIS)

    Todo, Alberto S.; Gerulis, Eduardo; Cardoso, Joaquim C.S.; Rodrigues Junior, Orlando

    2015-01-01

    The internal dosimetry program at the Instituto de Pesquisas Energeticas e Nucleares, IPEN, is accomplished in two steps: the activity measurements are performed at the In Vivo Monitoring Laboratory and subsequently the data analysis and the dose evaluation are carried out by the Dose Calculation Group according to the ICRP models. The objective of this study is to take the whole body and thyroid monitoring results recorded from 2005 to 2015 to see whether the internal contamination control procedure for workers were suitable even with the increase in the radiopharmaceutical production. The study were based in a research called “Search of Variables” for the operations carried out in the restricted areas of radiopharmaceutical production plant, taking into account the dose distribution data for all the tasks recorded by the radioprotection service. This methodology aims to identify and determine the principal variables that impact on the worker's dose. The results were presented for the following variables: individual occupationally exposed, operation variable, area/cell, type of task of operation, which depend on the variable dose. In spite of growth rate in the production of radiopharmaceutical, this study has shown that the improvements in the plant have contributed to the dose reduction of the workers. (author)

  11. Comparison between evaluating methods about the protocols of different dose distributions in radiotherapy

    International Nuclear Information System (INIS)

    Ju Yongjian; Chen Meihua; Sun Fuyin; Zhang Liang'an; Lei Chengzhi

    2004-01-01

    Objective: To study the relationship between tumor control probability (TCP) or equivalent uniform dose (EUD) and the heterogeneity degree of the dose changes with variable biological parameter values of the tumor. Methods: According to the definitions of TCP and EUD, calculating equations were derived. The dose distributions in the tumor were assumed to be Gaussian ones. The volume of the tumor was divided into several voxels, and the absorbed doses of these voxels were simulated by Monte Carlo methods. Then with the different values of radiosensitivity (α) and potential doubling time of the clonogens (T p ), the relationships between TCP or EUD and the standard deviation of dose (S d ) were evaluated. Results: The TCP-S d curves were influenced by the variable α and T p values, but the EUD-S d curves showed little variation. Conclusion: When the radiotherapy protocols with different dose distributions are compared, if the biological parameter values of the tumor have been known exactly, it's better to use the TCP, otherwise the EUD will be preferred

  12. Field evaluations of the VDmax approach for substantiation of a 25 kGy sterilization dose and its application to other preselected doses

    International Nuclear Information System (INIS)

    Kowalski, John B.; Herring, Craig; Baryschpolec, Lisa; Reger, John; Patel, Jay; Feeney, Mary; Tallentire, Alan

    2002-01-01

    The International and European standards for radiation sterilization require evidence of the effectiveness of a minimum sterilization dose of 25 kGy but do not provide detailed guidance on how this evidence can be generated. An approach, designated VD max , has recently been described and computer evaluated to provide safe and unambiguous substantiation of a 25 kGy sterilization dose. The approach has been further developed into a practical method, which has been subjected to field evaluations at three manufacturing facilities which produce different types of medical devices. The three facilities each used a different overall evaluation strategy: Facility A used VD max for quarterly dose audits; Facility B compared VD max and Method 1 in side-by-side parallel experiments; and Facility C, a new facility at start-up, used VD max for initial substantiation of 25 kGy and subsequent quarterly dose audits. A common element at all three facilities was the use of 10 product units for irradiation in the verification dose experiment. The field evaluations of the VD max method were successful at all three facilities; they included many different types of medical devices/product families with a wide range of average bioburden and sample item portion values used in the verification dose experiments. Overall, around 500 verification dose experiments were performed and no failures were observed. In the side-by-side parallel experiments, the outcomes of the VD max experiments were consistent with the outcomes observed with Method 1. The VD max approach has been extended to sterilization doses >25 and max method for doses other than 25 kGy must await controlled field evaluations and the development of appropriate specifications/standards

  13. Use of thermoluminescence dosimetry for evaluation of internal beta dose-rate in archaeological dating

    Energy Technology Data Exchange (ETDEWEB)

    Bailiff, I K; Aitken, M J [Oxford Univ. (UK). Research Lab. for Archaeology

    1980-07-01

    An experimental technique is described for the absolute determination of beta dose-rate in pottery. The calibrated system utilizes thermoluminescent dosimeters (natural calcium fluoride) which are located external to the pottery sample. These measurements give an evaluation of the dose-rate at the centre of the pottery that is effectively independent of the relative importance of the thorium, uranium and potassium content (typically 12 ppm Th, 3 ppm U and 1% K/sub 2/O in pottery). This has been checked using analysed uranium, thorium and potassium materials. A dose-rate evaluation may be made after 10-14 d with an accuracy of +-5%, where the dose-rate to the dosimeter is of the order of 0.3 mrad d/sup -1/. Although the background dose-rate due to cosmic radiation and that arising from radioactive impurities in the calcium fluoride is significant (one third), measurements have shown that it may be accurately established. The technique described is to be preferred to other systems used in pottery dating because of its independence of relative radioisotope concentration.

  14. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose (MTD) in Future Studies.

    Science.gov (United States)

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2015-07-01

    High doses in Tg.rasH2 carcinogenicity studies are usually set at the maximum tolerated dose (MTD), although this dose selection strategy has not been critically evaluated. We analyzed the body weight gains (BWGs), mortality, and tumor response in control and treated groups of 29 Tg.rasH2 studies conducted at BioReliance. Based on our analysis, it is evident that the MTD was exceeded at the high and/or mid-doses in several studies. The incidence of tumors in high doses was lower when compared to the low and mid-doses of both sexes. Thus, we recommend that the high dose in male mice should not exceed one-half of the estimated MTD (EMTD), as it is currently chosen, and the next dose should be one-fourth of the EMTD. Because females were less sensitive to decrements in BWG, the high dose in female mice should not exceed two-third of EMTD and the next dose group should be one-third of EMTD. If needed, a third dose group should be set at one-eighth EMTD in males and one-sixth EMTD in females. In addition, for compounds that do not show toxicity in the range finding studies, a limit dose should be applied for the 26-week carcinogenicity studies. © 2014 by The Author(s).

  15. Evaluation of patient absorbed dose in a PET-CT test

    International Nuclear Information System (INIS)

    Guerra P, F.; Mourao F, A. P.; Santana, P. C.

    2017-10-01

    Images of PET-CT has important diagnostic applications, especially in oncology. This equipment allows overlapping of functional images obtained from the administration of radionuclides and anatomical, generated by X-rays. The PET-CT technique may generate higher doses in patients due to the fact that two diagnostic modalities are used in a single examination. A whole body CT scan is performed and in sequence, a capture of the signal generated by the photons emitted is done. In this study, the absorbed and effective doses generated by the CT scan and incorporated by the administration of the radionuclide were evaluated in 19 organs. To evaluate the CT dose, 32 radiochromic film strips were correctly positioned into the anthropomorphic male phantom. The CT protocol performed was whole-body scanning and a high-resolution lung scan. This protocol is currently used in most services. The calculation of the effective dose from the injected activity in the patient was performed using the ICRP 106 Biokinetic model (ICRP 106, 2008). The activity to be injected may vary according to the patients body mass and with the sensitivity of the detector. The mass of the simulator used is 73.5 kg, then the simulation with and injected activity of 244.76 MBq was used. It was observed that 87.4% of the effective dose in examination PET/CT comes from the CT scans, being 63.8% of the whole body scan and 23.6% of high resolution lung scan. Using activity of 0.09 mCi x kg 18 F-FDG radiopharmaceutical contributes only 12.6% of the final effective dose. As a conclusion, it was observed that the dose in patients submitted to the 18 F-FDG PET-CT examination is high, being of great value efforts for its reduction, such as the use of appropriate image acquisition techniques and promoting the application of the principle of optimization of practice. (Author)

  16. Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

    International Nuclear Information System (INIS)

    Souza, Edmilson M.; Lima, Marco A.F.; Kelecom, Alphonse; Correa, Samanda C.A.; Silva, Ademir X.; Brito, Alan

    2008-01-01

    Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intraoral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

  17. SU-E-T-161: Evaluation of Dose Calculation Based On Cone-Beam CT

    International Nuclear Information System (INIS)

    Abe, T; Nakazawa, T; Saitou, Y; Nakata, A; Yano, M; Tateoka, K; Fujimoto, K; Sakata, K

    2014-01-01

    Purpose: The purpose of this study is to convert pixel values in cone-beam CT (CBCT) using histograms of pixel values in the simulation CT (sim-CT) and the CBCT images and to evaluate the accuracy of dose calculation based on the CBCT. Methods: The sim-CT and CBCT images immediately before the treatment of 10 prostate cancer patients were acquired. Because of insufficient calibration of the pixel values in the CBCT, it is difficult to be directly used for dose calculation. The pixel values in the CBCT images were converted using an in-house program. A 7 fields treatment plans (original plan) created on the sim-CT images were applied to the CBCT images and the dose distributions were re-calculated with same monitor units (MUs). These prescription doses were compared with those of original plans. Results: In the results of the pixel values conversion in the CBCT images,the mean differences of pixel values for the prostate,subcutaneous adipose, muscle and right-femur were −10.78±34.60, 11.78±41.06, 29.49±36.99 and 0.14±31.15 respectively. In the results of the calculated doses, the mean differences of prescription doses for 7 fields were 4.13±0.95%, 0.34±0.86%, −0.05±0.55%, 1.35±0.98%, 1.77±0.56%, 0.89±0.69% and 1.69±0.71% respectively and as a whole, the difference of prescription dose was 1.54±0.4%. Conclusion: The dose calculation on the CBCT images achieve an accuracy of <2% by using this pixel values conversion program. This may enable implementation of efficient adaptive radiotherapy

  18. Evaluation of the 'dose of the day' for IMRT prostate cancer patients derived from portal dose measurements and cone-beam CT

    International Nuclear Information System (INIS)

    Zijtveld, Mathilda van; Dirkx, Maarten; Breuers, Marcel; Kuipers, Ruud; Heijmen, Ben

    2010-01-01

    Purpose: High geometrical and dosimetrical accuracies are required for radiotherapy treatments where IMRT is applied in combination with narrow treatment margins in order to minimize dose delivery to normal tissues. As an overall check, we implemented a method for reconstruction of the actually delivered 3D dose distribution to the patient during a treatment fraction, i.e., the 'dose of the day'. In this article results on the clinical evaluation of this concept for a group of IMRT prostate cancer patients are presented. Materials and methods: The actual IMRT fluence maps delivered to a patient were derived from measured EPID-images acquired during treatment using a previously described iterative method. In addition, the patient geometry was obtained from in-room acquired cone-beam CT images. For dose calculation, a mapping of the Hounsfield Units from the planning CT was applied. With the fluence maps and the modified cone-beam CT the 'dose of the day' was calculated. The method was validated using phantom measurements and evaluated clinically for 10 prostate cancer patients in 4 or 5 fractions. Results: The phantom measurements showed that the delivered dose could be reconstructed within 3%/3 mm accuracy. For prostate cancer patients, the isocenter dose agreed within -0.4 ± 1.0% (1 SD) with the planned value, while for on average 98.1% of the pixels within the 50% isodose surface the actually delivered dose agreed within 3% or 3 mm with the planned dose. For most fractions, the dose coverage of the prostate volume was slightly deteriorated which was caused by small prostate rotations and small inaccuracies in fluence delivery. The dose that was delivered to the rectum remained within the constraints used during planning. However, for two patients a large degrading of the dose delivery was observed in two fractions. For one patient this was related to changes in rectum filling with respect to the planning CT and for the other to large intra-fraction motion during

  19. Evaluation of an electron Monte Carlo dose calculation algorithm for treatment planning.

    Science.gov (United States)

    Chamberland, Eve; Beaulieu, Luc; Lachance, Bernard

    2015-05-08

    The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system's behavior in simple geometries and in configurations encountered in clinical practice. The first series of tests were executed in a homogeneous water phantom, where experimental measurements and eMC-calculated dose distributions were compared for various combinations of energy and applicator. More specifically, we compared beam profiles and depth-dose curves at different source-to-surface distances (SSDs) and gantry angles, by using dose difference and distance to agreement. Also, we compared output factors, we studied the effects of algorithm input parameters, which are the random number generator seed, as well as the calculation grid size, and we performed a calculation time evaluation. Three different inhomogeneous solid phantoms were built, using high- and low-density materials inserts, to clinically simulate relevant heterogeneity conditions: a small air cylinder within a homogeneous phantom, a lung phantom, and a chest wall phantom. We also used an anthropomorphic phantom to perform comparison of eMC calculations to measurements. Finally, we proceeded with an evaluation of the eMC algorithm on a clinical case of nose cancer. In all mentioned cases, measurements, carried out by means of XV-2 films, radiographic films or EBT2 Gafchromic films. were used to compare eMC calculations with dose distributions obtained from an electron pencil beam algorithm. eMC calculations in the water phantom were accurate. Discrepancies for depth-dose curves and beam profiles were under 2.5% and 2 mm. Dose calculations with eMC for the small air cylinder and the lung phantom agreed within 2% and 4%, respectively. eMC calculations for the chest wall phantom and the anthropomorphic phantom also

  20. A model to incorporate organ deformation in the evaluation of dose/volume relationship

    International Nuclear Information System (INIS)

    Yan, D.; Jaffray, D.; Wong, J.; Brabbins, D.; Martinez, A. A.

    1997-01-01

    Purpose: Measurements of internal organ motion have demonstrated that daily organ deformation exists during the course of radiation treatment. However, a model to evaluate the resultant dose delivered to a daily deformed organ remains a difficult challenge. Current methods which model such organ deformation as rigid body motion in the dose calculation for treatment planning evaluation are incorrect and misleading. In this study, a new model for treatment planning evaluation is introduced which incorporates patient specific information of daily organ deformation and setup variation. The model was also used to retrospectively analyze the actual treatment data measured using daily CT scans for 5 patients with prostate treatment. Methods and Materials: The model assumes that for each patient, the organ of interest can be measured during the first few treatment days. First, the volume of each organ is delineated from each of the daily measurements and cumulated in a 3D bit-map. A tissue occupancy distribution is then constructed with the 50% isodensity representing the mean, or effective, organ volume. During the course of treatment, each voxel in the effective organ volume is assumed to move inside a local 3D neighborhood with a specific distribution function. The neighborhood and the distribution function are deduced from the positions and shapes of the organ in the first few measurements using the biomechanics model of viscoelastic body. For each voxel, the local distribution function is then convolved with the spatial dose distribution. The latter includes also the variation in dose due to daily setup error. As a result, the cumulative dose to the voxel incorporates the effects of daily setup variation and organ deformation. A ''variation adjusted'' dose volume histogram, aDVH, for the effective organ volume can then be constructed for the purpose of treatment evaluation and optimization. Up to 20 daily CT scans and daily portal images for 5 patients with prostate

  1. Environmental radioactivity and dose evaluation in Taiwan after the Chernobyl accident

    International Nuclear Information System (INIS)

    Chung, C.E.

    1989-01-01

    A substantial increase in fission product activity was observed in various environmental samples taken in Taiwan after the Chernobyl accident. The concentration of long-lived fission products in air above ground, precipitation, grass, vegetation and milk were monitored in the next 7 wk. The individual effective dose equivalent committed by the first year of exposure and intake following the accident were evaluated. Average individual doses for the population in Taiwan are estimated at 0.9 microSv due to global fallout from the Chernobyl accident. This value is lower than that reported in neighboring countries in the Far East and poses no increased health impact to the public in Taiwan

  2. Significance of the evaluation of radiation dose at the site boundary

    International Nuclear Information System (INIS)

    Takitani, Koichi

    2013-01-01

    Nuclear Regulation Authority, Japan, is drawing up new regulation standards for the light water reactors. The focal point of the new regulation drawing is how 'the safeguard against the release of radioactive materials at possible severe accident' should be shaped up. Checking the radiation dose rate at the site boundary is indispensable for the evaluation of the efficiency of measures against the severe accident. 'Avoiding radiation hazard on habitants' should be included in the regulation. The critical dose may be 100mSv for whole body and 1000mSv for the children's thyroid gland. (J.P.N.)

  3. Evaluation of effective dose in an anthropomorphic phantom in radiological emergencies situations

    International Nuclear Information System (INIS)

    Silva, Livia K. da; Ribeiro, Rosane M.; Santos, Denison de S.

    2013-01-01

    This work aims to implement the code of Monte Carlo Geant4 in a male and female phantom, ADAM and EVA, to be able to evaluate the dose in individuals who have been exposed externally to ionizing radiation sources so that in the future be made a review within the limits of validity of the terms contained in TECDOC-1162, published by the International Atomic Energy Agency (IAEA), which recommends formulas for the effective dose assessment in individuals who have been exposed to external radiation sources in various geometric configurations and for various radionuclides

  4. Evaluation of subject contrast and normalized average glandular dose by semi-analytical models

    International Nuclear Information System (INIS)

    Tomal, A.; Poletti, M.E.; Caldas, L.V.E.

    2010-01-01

    In this work, two semi-analytical models are described to evaluate the subject contrast of nodules and the normalized average glandular dose in mammography. Both models were used to study the influence of some parameters, such as breast characteristics (thickness and composition) and incident spectra (kVp and target-filter combination) on the subject contrast of a nodule and on the normalized average glandular dose. From the subject contrast results, detection limits of nodules were also determined. Our results are in good agreement with those reported by other authors, who had used Monte Carlo simulation, showing the robustness of our semi-analytical method.

  5. Evaluation of the low dose cardiac CT imaging using ASIR technique

    Science.gov (United States)

    Fan, Jiahua; Hsieh, Jiang; Deubig, Amy; Sainath, Paavana; Crandall, Peter

    2010-04-01

    Today Cardiac imaging is one of the key driving forces for the research and development activities of Computed Tomography (CT) imaging. It requires high spatial and temporal resolution and is often associated with high radiation dose. The newly introduced ASIR technique presents an efficient method that offers the dose reduction benefits while maintaining image quality and providing fast reconstruction speed. This paper discusses the study of image quality of the ASIR technique for Cardiac CT imaging. Phantoms as well as clinical data have been evaluated to demonstrate the effectiveness of ASIR technique for Cardiac CT applications.

  6. Compendium of cost-effectiveness evaluations of modifications for dose reduction at nuclear power plants

    International Nuclear Information System (INIS)

    Baum, J.W.; Matthews, G.R.

    1985-12-01

    This report summarizes available information on cost effectiveness of engineering modifications potentially valuable for dose reduction at nuclear power plants. Data were gathered from several US utilities, published literature, equipment and service suppliers, and recent technical meetings. Five simplified econometric models were employed to evaluate data and arrive at a value for cost effectiveness expressed in either (a) dollars/rem, or (b) total dollar savings calculated using a nominal value of $1000/rem. Models employed were: a basic model with no consideration given to the time value of money; two models in which discounting was used to evaluate costs and savings in terms of present values; and two models in which income taxes and revenue requirements were considered. Results from different models varied by as much as a factor of 10, and were generally lowest for the basic model and highest for the before-tax revenue requirements model. Results for 151 evaluations employing different assumptions concerning number of plants per site and outage impacts were tabulated in order of decreasing cost effectiveness. Twenty-five evaluations were identified as exceptionally cost effective since both costs and dose were saved. Forty evaluations indicated highly cost-effective changes based on costs below $1000/rem saved using results of the present-worth model that included discounting of future dose savings

  7. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions

    International Nuclear Information System (INIS)

    Podesta, Mark; Persoon, Lucas CGG; Verhaegen, Frank

    2014-01-01

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors. The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation

  8. A new method for determining the Curie temperature using a dilatometer

    International Nuclear Information System (INIS)

    Verma, A; Sundararaman, M; Singh, J B; Nalawade, S A

    2010-01-01

    Dilatometry is a tool used for the study of dimensional changes in materials as a function of temperature and also to identify phase transformations including magnetic transformations. In this paper, we describe two new methods that can be employed in an inductively heated dilatometer to determine the Curie temperature in metallic ferromagnetic materials. These methods are based on the fundamental magnetic properties of materials such as hysteresis loss and anomalous thermal conductivity changes near the Curie point. These methods have been used to determine the Curie point in nickel, iron and Co–5 at% Ni alloy. The values obtained match well with those reported in the literature. The effects of the geometry of the specimen and of the push-rod material on the measurement sensitivity of the transition temperature have been discussed

  9. Evaluation of reduced-dose CT for acute non-traumatic abdominal pain: evaluation of diagnostic accuracy in comparison to standard-dose CT.

    Science.gov (United States)

    Othman, Ahmed E; Bongers, Malte Niklas; Zinsser, Dominik; Schabel, Christoph; Wichmann, Julian L; Arshid, Rami; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

    2018-01-01

    Background Patients with acute non-traumatic abdominal pain often undergo abdominal computed tomography (CT). However, abdominal CT is associated with high radiation exposure. Purpose To evaluate diagnostic performance of a reduced-dose 100 kVp CT protocol with advanced modeled iterative reconstruction as compared to a linearly blended 120 kVp protocol for assessment of acute, non-traumatic abdominal pain. Material and Methods Two radiologists assessed 100 kVp and linearly blended 120 kVp series of 112 consecutive patients with acute non-traumatic pain (onset diagnostic confidence. Both 100 kVp and linearly blended 120 kVp series were quantitatively evaluated regarding radiation dose and image noise. Comparative statistics and diagnostic accuracy was calculated using receiver operating curve (ROC) statistics, with final clinical diagnosis/clinical follow-up as reference standard. Results Image quality was high for both series without detectable significant differences ( P = 0.157). Image noise and artifacts were rated low for both series but significantly higher for 100 kVp ( P ≤ 0.021). Diagnostic accuracy was high for both series (120 kVp: area under the curve [AUC] = 0.950, sensitivity = 0.958, specificity = 0.941; 100 kVp: AUC ≥ 0.910, sensitivity ≥ 0.937, specificity = 0.882; P ≥ 0.516) with almost perfect inter-rater agreement (Kappa = 0.939). Diagnostic confidence was high for both dose levels without significant differences (100 kVp 5, range 4-5; 120 kVp 5, range 3-5; P = 0.134). The 100 kVp series yielded 26.1% lower radiation dose compared with the 120 kVp series (5.72 ± 2.23 mSv versus 7.75 ± 3.02 mSv, P diagnostic accuracy for the assessment of acute non-traumatic abdominal pain.

  10. Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

    International Nuclear Information System (INIS)

    Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

    2014-01-01

    With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

  11. Effective dose evaluation of NORM-added consumer products using Monte Carlo simulations and the ICRP computational human phantoms

    International Nuclear Information System (INIS)

    Lee, Hyun Cheol; Yoo, Do Hyeon; Testa, Mauro; Shin, Wook-Geun; Choi, Hyun Joon; Ha, Wi-Ho; Yoo, Jaeryong; Yoon, Seokwon; Min, Chul Hee

    2016-01-01

    The aim of this study is to evaluate the potential hazard of naturally occurring radioactive material (NORM) added consumer products. Using the Monte Carlo method, the radioactive products were simulated with ICRP reference phantom and the organ doses were calculated with the usage scenario. Finally, the annual effective doses were evaluated as lower than the public dose limit of 1 mSv y"−"1 for 44 products. It was demonstrated that NORM-added consumer products could be quantitatively assessed for the safety regulation. - Highlights: • Consumer products considered that NORM would be included should be regulated. • 44 products were collected and its gamma activities were measured with HPGe detector. • Through Monte Carlo simulation, organ equivalent doses and effective doses on human phantom were calculated. • All annual effective doses for the products were evaluated as lower than dose limit for the public.

  12. Evaluation of indoor radon equilibrium factor using CFD modeling and resulting annual effective dose

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2018-04-01

    The equilibrium factor is an important parameter for reasonably estimating the population dose from radon. However, the equilibrium factor value depended mainly on the ventilation rate and the meteorological factors. Therefore, this study focuses on investigating numerically the influence of the ventilation rate, temperature and humidity on equilibrium factor between radon and its progeny. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on indoor equilibrium factor. The variations of equilibrium factor with the ventilation, temperature and relative humidity are discussed. Moreover, the committed equivalent doses due to 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of indoor air. The annual effective dose due to radon short lived progeny from the inhalation of indoor air by the members of the public was investigated.

  13. Dose Evaluation of Neutron within Containment Building of a CE type Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Wook; Han, Jae Mun; Kim, Kyung Doek; Yun, Cheol Whan; Suh, Jang Soo; Kim, Young Jae [Nuclear Environment Technology Institute, Daejeon (Korea, Republic of)

    2005-03-15

    From measured results of the neutron fields at some principal places within the containment building in a CE type nuclear power plant in operation, the radiation exposure of a worker to the neutron at there was evaluated and the equivalent dose reflecting new recommendation (ICRP 60) was compared with that doing the old one (ICRP 26). The measured neutron field was also compared with calibration neutron field. From the analysis, the following conclusion was obtained: the average neutron radiation weighting factor according to new recommendation is 2.41 to 2.71 times higher than the old one. The average neutron radiation weighting factor at the measured place was similar to that at calibration neutron field. The average neutron energy at measured place was between 42 and 158 keV and higher than that of calibration field of 500 keV. So, the measured equivalent dose in nuclear power plant could be overestimated compared to the real equivalent dose.

  14. Evaluation of the breast absorbed dose distribution using the Fricke Xylenol Gel

    International Nuclear Information System (INIS)

    Czelusniak, C; Del Lama, L S; Moreira, M V; De Almeida, A

    2010-01-01

    During a breast cancer radiotherapy treatment, several issues have to be taken into account, among them, hot spots, gradient of doses delivered over the breast, as well as in the lungs and the heart. The present work aims to apply the Fricke Xylenol Gel (FXG) dosimeter in the study of these issues, using a CCD camera to analyse the dose deposited distribution. Thus, the CCD was used to capture the images of different cuvettes that were filled with FXG and irradiated considering analogous setups employed in breast cancer radiotherapy treatments. Thereafter, these pictures where processed in a MatLab routine and the spatial dose distributions could be evaluated. These distributions were compared with the ones that were obtained from dedicated treatment planning's softwares. According to the results obtained, the FXG, allied with the CCD system, has shown to be a complementary tool in dosimetry, helping to prevent possible complications during breast cancer treatments.

  15. Radiation dose evaluation for hypothetical accident with transport package containing Iridium-192 source

    International Nuclear Information System (INIS)

    Trontl, K.; Bace, M.; Pevec, D.

    2002-01-01

    The aim of this paper is to evaluate dose rates for a hypothetical accident with transport package containing Iridium-192 source and to design additional shielding necessary for the safe unloading of the container, assuming that during the unloading process the whole contents of a radioactive source is unshielded and that the operation is going to take place at the site where a working area exists in the vicinity of the unloading location. Based on the calculated radiation dose rates, a single arrangement of the additional concrete shields necessary for reduction of the gamma dose rates to the permitted level is proposed. The proposed solution is optimal considering safety on one hand and costs on the other.(author)

  16. An evaluation of the impact of digital imaging on radiographic practice and patient doses

    Science.gov (United States)

    Horrocks, J.; Violaki, K.

    2015-09-01

    Direct digital imaging technology was implemented in all areas in general and mobile radiology at Barts and the Royal London Hospitals in 2012. Evidence from recent radiation incident investigations indicates optimum exposure factors are not consistently selected, with the greater dynamic range of the digital detectors allowing sub-optimal practice. To investigate further patient dose data were extracted from the Radiology Information System for adult chest X-ray examinations in 2014, covering over 50,000 studies in the Trust. Chest X-ray examinations were selected as they are low dose but frequent examinations. The patient dose data were evaluated taking into account X-ray system type and detector performance measurements, and individual cases studies were used to highlight where practice can be improved.

  17. Social-demographic profile and dose evaluation of the radiopharmaceutical facility workers

    International Nuclear Information System (INIS)

    Sanches, Matias P.; Carneiro, Janete C. Gaburo; Sordi, Gian Maria A.A.

    2009-01-01

    The main aims of this work are to identify the social-demographic profile of the workers based on stratification variables such as gender, age, and tasks performed by the workers, and to evaluate the annual collective doses of workers with potential risk of ionizing radiation exposure at the workplace during the years 2004 to 2008. In this context, the knowledge of the workforce composition in the facility responsible for the radioisotope production and its distribution was used. The individual monitoring programme has been carried out by individual dosimeters, TLDs, and internal contamination monitoring (in vivo method). The reported doses, in the period studied, suggest that the external exposure was the main source of occupational exposure in radioisotope production and distribution areas. The internal exposure was not included in the doses estimated, because it was negligible. This study has an important exploratory character, in order to analyze possible correlations related to adverse health effects, aiming to provide directions for occupational epidemiology research. (author)

  18. Evaluation of glasses containing cadmium for high dose dosimetry by the thermoluminescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Gabriel Soares Marchiori de; Ferreira, Pamela Zati; Cunha, Diego Merigue da; Dantas, Noelio Oliveira; Silva, Anielle C.A.; Perini, Ana Paula; Neves, Lucio Pereira, E-mail: lucio.neves@ufu.br [Universidade Federal de Uberlandia (INFIS/UFU), MG (Brazil). Instituto de Fisica; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Carrera, Betzabel Noemi Silva; Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), SP (Brazil). Instituto de Fisica

    2016-07-01

    New glass matrices were evaluated for high dose dosimetry by the thermoluminescence technique. Their nominal composition are 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.15CdO.55B{sub 2}O{sub 3} and 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.20CdO.50B{sub 2}O{sub 3} (mol%). The glass matrices were irradiated with different doses: 50, 100, 200, 500, 700 and 900 Gy, and the thermoluminescence emission curves were obtained for each of these values. The results show a great potential of using these matrices in high dose dosimetry. (author)

  19. Evaluation of the breast absorbed dose distribution using the Fricke Xylenol Gel

    Energy Technology Data Exchange (ETDEWEB)

    Czelusniak, C; Del Lama, L S; Moreira, M V; De Almeida, A, E-mail: dalmeida@ffclrp.usp.b

    2010-11-01

    During a breast cancer radiotherapy treatment, several issues have to be taken into account, among them, hot spots, gradient of doses delivered over the breast, as well as in the lungs and the heart. The present work aims to apply the Fricke Xylenol Gel (FXG) dosimeter in the study of these issues, using a CCD camera to analyse the dose deposited distribution. Thus, the CCD was used to capture the images of different cuvettes that were filled with FXG and irradiated considering analogous setups employed in breast cancer radiotherapy treatments. Thereafter, these pictures where processed in a MatLab routine and the spatial dose distributions could be evaluated. These distributions were compared with the ones that were obtained from dedicated treatment planning's softwares. According to the results obtained, the FXG, allied with the CCD system, has shown to be a complementary tool in dosimetry, helping to prevent possible complications during breast cancer treatments.

  20. Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b₁.

    Science.gov (United States)

    Direito, Glória M; Almeida, Adriana P; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

    2009-01-01

    The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

  1. Social-demographic profile and dose evaluation of the radiopharmaceutical facility workers

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Matias P.; Carneiro, Janete C. Gaburo; Sordi, Gian Maria A.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: msanches@ipen.br

    2009-07-01

    The main aims of this work are to identify the social-demographic profile of the workers based on stratification variables such as gender, age, and tasks performed by the workers, and to evaluate the annual collective doses of workers with potential risk of ionizing radiation exposure at the workplace during the years 2004 to 2008. In this context, the knowledge of the workforce composition in the facility responsible for the radioisotope production and its distribution was used. The individual monitoring programme has been carried out by individual dosimeters, TLDs, and internal contamination monitoring (in vivo method). The reported doses, in the period studied, suggest that the external exposure was the main source of occupational exposure in radioisotope production and distribution areas. The internal exposure was not included in the doses estimated, because it was negligible. This study has an important exploratory character, in order to analyze possible correlations related to adverse health effects, aiming to provide directions for occupational epidemiology research. (author)

  2. A method to evaluate the dose increase in CT with iodinated contrast medium

    International Nuclear Information System (INIS)

    Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio

    2010-01-01

    Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical protocols

  3. A method to evaluate the dose increase in CT with iodinated contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio [Department of Radiological Sciences, University of Messina, Messina 98125 (Italy); Department of Physics, University of Messina, Messina 98166 (Italy); University Hospital ' ' G. Martino' ' , Messina 98125 (Italy); Department of Radiological Sciences, University of Messina, Messina 98125 (Italy) and University Hospital ' ' G. Martino' ' , Messina 98125 (Italy)

    2010-08-15

    Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical

  4. Study on the curie transition of P(VDF-TrFE) copolymer

    Science.gov (United States)

    Eka Septiyani Arifin, Devi; Ruan, J. J.

    2018-01-01

    A systematic study was carried out to decipher the mechanism of Curie transition of piezoelectric crystals of poly(vinylidene fluoride trifluoroethylene) P(VDF-TrFE). The unique polarity of P(VDF-TrFE) crystalline phase below curie transition temperature is attributed to the lattice packing of all-trans molecular chains, which allocates all the substituted fluorine atoms on one side of molecular chains and hydrogen atoms on the other side. Therefore, a net dipole moment is created across the lateral packing of molecular chains. Nevertheless, due to the mutual repulsion among fluorene atoms, this all-trans conformation is not stable, and ready to change above Curie temperature, where thermal kinetic energy is sufficient to cause segmental rotation. As being illustrated by in-situ recorded X-ray diffraction and thermal analysis, the concerned curie transition is deciphered as a one-step process which is involved two process and this is different from conventional one-step solid-solid transitions. Accompanied with this one-step process during heating, the occurrence of lamellar bending is inferred for elucidating the decline of stacking regularity of crystalline lamellae, which reversibly recover during subsequent cooling. However, as the crystalline lamellae of P(VDF-TrFE) are confined in between the stacking of crystalline lamellae of PVDF, lamellar bending is restricted accordingly. As a result, a certain fraction of the piezoelectric crystalline lamellae was found to survive through the Curie transition. Thus, in addition to the suggestion of a one-step process as a new concept for understanding the Curie transition, the relationship between the lamellar stacking and transition of molecular packing is unveiled as well in this research.

  5. Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT: comparison of commercially available Monte Carlo dose calculation with other algorithms

    Directory of Open Access Journals (Sweden)

    Takahashi Wataru

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC calculations, in actual computed tomography (CT scans for use in stereotactic radiotherapy (SRT of small lung cancers. Methods Slow CT scan of 20 patients was performed and the internal target volume (ITV was delineated on Pinnacle3. All plans were first calculated with a scatter homogeneous mode (SHM which is compatible with Clarkson algorithm using Pinnacle3 treatment planning system (TPS. The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs. Collapsed cone convolution (CCC from Pinnacle3, superposition (SP from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs were compared with each other. Results The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC doses and the minimal dose received by 95% of the PTV (PTV95 compared to XVMC. The differences in mean doses were 2.96 Gy (6.17% for IC and 5.02 Gy (11.18% for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17, and -2.67% (p = 0.0036, respectively. Conclusions Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.

  6. SU-F-T-474: Evaluation of Dose Perturbation, Temperature and Sensitivity Variation With Accumulated Dose of MOSFET Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, B; Prakasarao, A; Singaravelu, G [Anna University, Chennai, TamilNadu (India); Palraj, T; Rai, R [Dr. Rai Memorial Cancer Institute, Chennai, TamilNadu (India)

    2016-06-15

    Purpose: The use of mega voltage gamma and x-ray sources with their skin sparring qualities in radiation therapy has been a boon in relieving patient discomfort and allowing high tumor doses to be given with fewer restrictions due to radiation effects in the skin. However, high doses given to deep tumors may require careful consideration of dose distribution in the buildup region in order to avoid irreparable damage to the skin. Methods: To measure the perturbation of MOSFET detector in Co60,6MV and 15MV the detector was placed on the surface of the phantom covered with the brass build up cap. To measure the effect of temperature the MOSFET detector was kept on the surface of hot water polythene container and the radiation was delivere. In order to measure the sensitivity variation with accumulated dose Measurements were taken by delivering the dose of 200 cGy to MOSFET until the MOSFET absorbed dose comes to 20,000 cGy Results: the Measurement was performed by positioning the bare MOSFET and MOSFET with brass build up cap on the top surface of the solid water phantom for various field sizes in order to find whether there is any attenuation caused in the dose distribution. The response of MOSFET was monitored for temperature ranging from 42 degree C to 22 degree C. The integrated dose dependence of MOSFET dosimeter sensitivity over different energy is not well characterized. This work investigates the dual-bias MOSFET dosimeter sensitivity response to 6 MV and 15 MV beams. Conclusion: From this study it is observed that unlike diode, bare MOSFET does not perturb the radiation field.. It is observed that the build-up influences the temperature dependency of MOSFET and causes some uncertainty in the readings. In the case of sensitivity variation with accumulated dose MOSFET showed higher sensitivity with dose accumulation for both the energies.

  7. SU-F-T-474: Evaluation of Dose Perturbation, Temperature and Sensitivity Variation With Accumulated Dose of MOSFET Detector

    International Nuclear Information System (INIS)

    Ganesan, B; Prakasarao, A; Singaravelu, G; Palraj, T; Rai, R

    2016-01-01

    Purpose: The use of mega voltage gamma and x-ray sources with their skin sparring qualities in radiation therapy has been a boon in relieving patient discomfort and allowing high tumor doses to be given with fewer restrictions due to radiation effects in the skin. However, high doses given to deep tumors may require careful consideration of dose distribution in the buildup region in order to avoid irreparable damage to the skin. Methods: To measure the perturbation of MOSFET detector in Co60,6MV and 15MV the detector was placed on the surface of the phantom covered with the brass build up cap. To measure the effect of temperature the MOSFET detector was kept on the surface of hot water polythene container and the radiation was delivere. In order to measure the sensitivity variation with accumulated dose Measurements were taken by delivering the dose of 200 cGy to MOSFET until the MOSFET absorbed dose comes to 20,000 cGy Results: the Measurement was performed by positioning the bare MOSFET and MOSFET with brass build up cap on the top surface of the solid water phantom for various field sizes in order to find whether there is any attenuation caused in the dose distribution. The response of MOSFET was monitored for temperature ranging from 42 degree C to 22 degree C. The integrated dose dependence of MOSFET dosimeter sensitivity over different energy is not well characterized. This work investigates the dual-bias MOSFET dosimeter sensitivity response to 6 MV and 15 MV beams. Conclusion: From this study it is observed that unlike diode, bare MOSFET does not perturb the radiation field.. It is observed that the build-up influences the temperature dependency of MOSFET and causes some uncertainty in the readings. In the case of sensitivity variation with accumulated dose MOSFET showed higher sensitivity with dose accumulation for both the energies.

  8. A study on the evaluation of radiation doses in dental radiography

    International Nuclear Information System (INIS)

    Sugimoto, Koju

    1980-01-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital. (J.P.N.)

  9. Why haven't either Bothe or Joliot-Curie discovered the neutron

    International Nuclear Information System (INIS)

    Six, J.

    1987-03-01

    Papers on neutron discovery often leave obscure questions on W. Bothe and F. Joliot and I. Curie works. Those points are analysed. Bothe realized an experiment sensitive almost only to gamma radiation and it was difficult, in these conditions, to find the neutron. Conversely, it has been forgotten that he was a pioneer in discovery of a gamma radiation induced by nuclear transmutations. A careful analysis of Joliot-Curie work leads to a new explanation of their non-discovery of the neutron. The principal reason is shown to be probably the contemporary idea influence on possibilities of energy non-conservation in nuclear processes [fr

  10. Studies of magnetic properties of thin microwires with low Curie temperature

    International Nuclear Information System (INIS)

    Zhukova, V.; Ipatov, M.; Zhukov, A.; Varga, R.; Torcunov, A.; Gonzalez, J.; Blanco, J.M.

    2006-01-01

    In this paper we report novel results on the fabrication and magnetic characterization of microwires with compositions Co 100- x -Fe-Ni x -Si-B and Co-Fe-Cr-Si-B fabricated by Taylor-Ulitovsky. Additions of Ni or Cr resulted in decreasing of the Curie temperature, T C . Few samples with low T C possessing also high GMI effect are obtained. Concrete temperature sensors applications based on the drastic change of magnetic properties in the vicinity of Curie temperature are shown

  11. Science har fundet løsning på CURIS-registrering

    DEFF Research Database (Denmark)

    Mørch, Frede

    2012-01-01

    Fakultetsbibliotekar Frede Mørch fortæller her om den løsning, som Science har indført for at sikre at alle forskningspublikationer bliver registreret i databasen, CURIS, uden at forskerne skal spilde tid på det.......Fakultetsbibliotekar Frede Mørch fortæller her om den løsning, som Science har indført for at sikre at alle forskningspublikationer bliver registreret i databasen, CURIS, uden at forskerne skal spilde tid på det....

  12. Modification of beta dose evaluation algorithm for better accuracy in personnel monitoring

    International Nuclear Information System (INIS)

    Rakesh, R.B.; Kumar, Munish; Sneha, C.; Ratna, P.; Datta, D.

    2016-01-01

    Dose due to beta radiations is the main contributor to the skin dose. Assessment of individual dose (whole body, skin, extremity) in India is based on CaSO 4 :Dy based Teflon embedded TLD badge used for personnel monitoring. The design of the dosemeter enables identification of radiation type which, in turn, allows use of radiation specific algorithm for dose evaluation. The difference of response of three discs of the TLD badge to beta radiation in beta/beta-gamma fields is due to the presence of different filters corresponding to the three discs. The response of disc under metal filter (D 1 ) to beta being negligible while that of open disc (D 3 ) is the maximum. The ratio of response of open disc to that under Perspex (D 3 /D 2 ) to beta is highly dependent on its energy and angle of incidence. Therefore estimation of dose due to beta is based on response of open disc corrected for the energy of beta using D 3 /D 2

  13. Usefulness evaluation of low-dose for emphysema: Compared with high-resolution CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jeong [Dept. of Radiological Technology, Daejeon Health Institute of Technology, Daejeon (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluate the usefulness of low-dose CT (LDCT) for emphysema compared with high-resolution CT (HRCT). Measurements of radiation dose and noise were repeated 3 times in same exposure condition which was similar with obtaining HRCT and LDCT images. We analysed reading results of 146 subjects. Six images per participants selected for emphysema grading. Emphysema was graded for all 6 zones on the left and right sides of the lungs by the consensus reading of two chest radiologists using a 4-point scale. Between the HRCT and LDCT images, diagnostic differences and agreements for emphysema were analyzed by McNemar's and unweighted kappa tests, and radiation doses and noise by a Mann-Whitney U-test, using the SPSS 19.0 program. Radiation dose from HRCT was significantly higher than that of LDCT, but the noise was significantly lower in HRCT than in LDCT. Diagnostic agreement for emphysema between HRCT and LDCT images was excellent (k-value=0.88). Emphysema grading scores were not significantly different between HRCT and LDCT images for all six lung zones. Emphysema grading scores from LDCT images were significantly correlated with increased scores on HRCT images (r=0.599, p < 0.001). Considering the tradeoff between radiation dose and image noise, LDCT could be used as the gold standard method instead of HRCT for emphysema detection and grading.

  14. Evaluation of homogeneity and dose conformity in IMRT planning in prostate radiotherapy

    International Nuclear Information System (INIS)

    Lopes, Juliane S.; Leidens, Matheus; Estacio, Daniela R.; Razera, Ricardo A.Z.; Streck, Elaine E.; Silva, Ana M.M. da

    2015-01-01

    The goal of this study was to evaluate the dose distribution homogeneity and conformity of radiation therapy plans of prostate cancer using IMRT. Data from 34 treatment plans of Hospital Sao Lucas of PUCRS, where those plans were executed, were retrospectively analyzed. All of them were done with 6MV X-rays from a linear accelerator CLINAC IX, and the prescription doses varied between 60 and 74 Gy. Analyses showing the homogeneity and conformity indices for the dose distribution of those plans were made. During these analyses, some comparisons with the traditional radiation therapy planning technic, the 3D-CRT, were discussed. The results showed that there is no correlation between the prescribed dose and the homogeneity and conformity indices, indicating that IMRT works very well even for higher doses. Furthermore, a comparison between the results obtained and the recommendations of ICRU 83 was carried out. It has also been observed that the indices were really close to the ideal values. 82.4% of the cases showed a difference below 5% of the ideal value for the index of conformity, and 88.2% showed a difference below 10% for the homogeneity index. Concluding, it is possible to confirm the quality of the analyzed radiation therapy plans of prostate cancer using IMRT. (author)

  15. Dose evaluation for digital X-ray imaging of premature neonates

    International Nuclear Information System (INIS)

    Minkels, T.J.M.; Jeukens, C.R.L.P.N.; Andriessen, P.; Van der Linden, A.N.; Dam, A.J.; Van Straaten, H.L.M.; Cottaar, E.J.E.; Van Pul, C.

    2017-01-01

    X-ray radiography is a commonly used diagnostic method for premature neonates. However, because of higher radiosensitivity and young age, premature neonates are more sensitive to the detrimental effects of ionising radiation. Therefore, it is important to monitor and optimise radiation doses at the neonatal intensive care unit (NICU). The number of X-ray examinations, dose area product (DAP) and effective doses are evaluated for three Dutch NICUs using digital flat panel detectors. Thorax, thorax abdomen and abdomen protocols are included in this study. Median number of examinations is equal to 1 for all three hospitals. Median DAP ranges between 0.05 and 1.02 μGy m2 for different examination types and different weight categories. These examinations result in mean effective doses between 4 ± 4 and 30 ± 10 μSv per examination. Substantial differences in protocols and doses can be observed between hospitals. This emphasises the need for up-to-date reference levels formulated specifically for premature neonates. (authors)

  16. Evaluation of the dose assessment models for routine radioactive releases to the environment

    International Nuclear Information System (INIS)

    Rossi, J.

    1998-05-01

    The aim of the work was to evaluate the needs of development concerning the dose calculation models for routine releases and application of the models for exceptional release situations at the NPP plants operated by Imatran Voima Ltd. and Teollisuuden Voima Ltd. in Finland. First, the differences of the calculation models concerning input data, models themselves and output are considered. Subsequently some single features like importance of nuclides in exposure pathways due to change of the release composition, dose calculation for children and importance of time period of particle releases are considered. The existing dose calculation model used by the radiation safety authorities is aimed at a tool for checking the results from calculations of doses arising from routine releases by the power companies. Characteristics of an independent, foreign model and its suitability for safety authorities for dose calculations of releases in normal operation is also assessed. The needs of improvements in the existing calculation models and characteristics of a comprehensive model for safety authorities are discussed as well

  17. Evaluation of occupational radiation dose in nuclear medicine: radiopharmaceutical administration to scintiscanning exams of myocardial perfusion

    International Nuclear Information System (INIS)

    Komatsu, Cassio V.; Michelin, Charlie A.; Jakubiak, Rosangela R.; Lemes, Alyne O.; Silva, Juliana L.M.

    2013-01-01

    In nuclear medicine, workers directly involved in exams are constantly exposed to ionizing radiation. The procedure for administration of the radiopharmaceutical to the patient is one of the most critical times of exposure. In tests of myocardial perfusion scintigraphy (MPS) administration of radiopharmaceutical repeats the steps of rest and cardiac stress. In this study, we used a Geiger -Mueller detector for measuring occupational radiation doses for during the administration of technetium- 99m - sestamibi in MPS tests. In the evaluation, discriminated the stages of examination and related professional experience time to doses measures at home. It were followed 110 procedures at home (55 conducted by professionals with over 5 years experience and 55 conducted by professionals with less than 1 year of experience) and 55 effort procedures. The results showed that the rest of the procedure time and dose are related to the experience of the worker. More experienced workers were faster (mean: 43 ± 16 vs 67 ± 25 seconds / procedure), and therefore received lower doses (mean 0.57 ± 0.16 versus 0.80 ± 0.24 μSv / procedure), both with statistical significance (p <0.001). In step effort, there were procedures lasting longer (mean: 19 ± 2 minutes / procedure), which resulted in higher doses (mean 3.0 ± 0.6 μSv / procedure)

  18. Evaluation of organ doses and specific k effective dose of 64-slice CT thorax examination using an adult anthropomorphic phantom

    International Nuclear Information System (INIS)

    Hashim, S.; Karim, M.K.A.; Bakar, K.A.; Sabarudin, A.; Chin, A.W; Saripan, M.I.; Bradley, D.A.

    2016-01-01

    The magnitude of radiation dose in computed tomography (CT) depends on the scan acquisition parameters, investigated herein using an anthropomorphic phantom (RANDO®) and thermoluminescence dosimeters (TLD). Specific interest was in the organ doses resulting from CT thorax examination, the specific k coefficient for effective dose estimation for particular protocols also being determined. For measurement of doses representing five main organs (thyroid, lung, liver, esophagus and skin), TLD-100 (LiF:Mg, Ti) were inserted into selected holes in a phantom slab. Five CT thorax protocols were investigated, one routine (R1) and four that were modified protocols (R2 to R5). Organ doses were ranked from greatest to least, found to lie in the order: thyroid>skin>lung>liver>breast. The greatest dose, for thyroid at 25 mGy, was that in use of R1 while the lowest, at 8.8 mGy, was in breast tissue using R3. Effective dose (E) was estimated using three standard methods: the International Commission on Radiological Protection (ICRP)-103 recommendation (E103), the computational phantom CT-EXPO (E(CTEXPO)) method, and the dose-length product (DLP) based approach. E103 k factors were constant for all protocols, ~8% less than that of the universal k factor. Due to inconsistency in tube potential and pitch factor the k factors from CTEXPO were found to vary between 0.015 and 0.010 for protocols R3 and R5. With considerable variation between scan acquisition parameters and organ doses, optimization of practice is necessary in order to reduce patient organ dose. - Highlights: • Using TLD-100 dosimeters and a RANDO phantom 5 CT thorax protocol organ doses were assessed. • The specific k coefficient for effective dose estimation of protocols differed with approach. • Organ dose was observed to decrease in the order: thyroid>skin>lung>liver>breast. • E103 k factors were constant for all protocols, lower by ~8% compared to the universal k factor.

  19. Method for the evaluation of a average glandular dose in mammography

    International Nuclear Information System (INIS)

    Okunade, Akintunde Akangbe

    2006-01-01

    This paper concerns a method for accurate evaluation of average glandular dose (AGD) in mammography. At different energies, the interactions of photons with tissue are not uniform. Thus, optimal accuracy in the estimation of AGD is achievable when the evaluation is carried out using the normalized glandular dose values, g(x,E), that are determined for each (monoenergetic) x-ray photon energy, E, compressed breast thickness (CBT), x, breast glandular composition, and data on photon energy distribution of the exact x-ray beam used in breast imaging. A generalized model for the values of g(x,E) that is for any arbitrary CBT ranging from 2 to 9 cm (with values that are not whole numbers inclusive, say, 4.2 cm) was developed. Along with other dosimetry formulations, this was integrated into a computer software program, GDOSE.FOR, that was developed for the evaluation of AGD received from any x-ray tube/equipment (irrespective of target-filter combination) of up to 50 kVp. Results are presented which show that the implementation of GDOSE.FOR yields values of normalized glandular dose that are in good agreement with values obtained from methodologies reported earlier in the literature. With the availability of a portable device for real-time acquisition of spectra, the model and computer software reported in this work provide for the routine evaluation of AGD received by a specific woman of known age and CBT

  20. Evaluation of the population dose due to the gaseous emission of a radioisotopes production unit

    International Nuclear Information System (INIS)

    Gordon, A.M.P.L.; Jacomino, V.M.F.; Sordi, G.-M.A.A.

    1990-05-01

    In order to control the emission of gaseous radioactive iodine from the unit responsible for the production of radioisotopes of IPEN-CNEN/SP, a discharge monitoring is carried out. In 1988 an activity of 65 GBq of I-131 was discharged to the environment. Based upon this value and the site analysis, the effective equivalent dose in the general public was evaluated for normal operation and for an incidental discharge. The evaluation was carried out by using a diffusion atmospheric model, 500 to 7000 m away from the discharge point and using 8 different wind direction sectors. The critical group was identified as being the people who lives 3000 m far from the discharge point, in the diffusion sector NW. The dose evaluated at this point is 10 9 times lower than the annual dose limit for individual of the public, according to Radiological Protection Standards. The derived limit for discharge of iodine was also evaluated and it was concluded that the IPEN-CNEN/SP can increase their production up to a level which results in an annual discharge of 1,5 x 10 12 of I-131. (author) [pt

  1. First impressions of 3D visual tools and dose volume histograms for plan evaluation

    International Nuclear Information System (INIS)

    Rattray, G.; Simitcioglu, A.; Parkinson, M.; Biggs, J.

    1999-01-01

    Converting from 2D to 3D treatment planning offers numerous challenges. The practices that have evolved in the 2D environment may not be applicable when translated into the 3D environment. One such practice is the methods used to evaluate a plan. In 2D planning a plane by plane comparison method is generally practiced. This type of evaluation method would not be appropriate for plans produced by a 3D planning system. To this end 3D dose displays and Dose Volume Histograms (DVHs) have been developed to facilitate the evaluation of such plans. A survey was conducted to determine the impressions of Radiation Therapists as they used these tools for the first time. The survey involved comparing a number of plans for a small group of patients and selecting the best plan for each patient. Three evaluation methods were assessed. These included the traditional plane by plane, 3D dose display, and DVHs. Those surveyed found the DVH to be the easiest of the three methods to use, with the 3D display being the next easiest. Copyright (1999) Blackwell Science Pty Ltd

  2. Patient radiation exposure dose evaluation of whole spine scanography due to exposure direction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su; Seo, Deok Nam [Dept. of Bio-convergence Engineering, Graduate School of Korea University, Seoul (Korea, Republic of); Kwon, Soon Mu [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of)

    2015-04-15

    Whole spine scanography (WSS) is a radiological examination that exposes the whole body of the individual being examined to x-ray radiation. WSS is often repeated during the treatment period, which results in a much greater radiation exposure than that in routine x-ray examinations. The aims of the current study were to evaluate the patient dose of WSS using computer simulation, image magnification and angulation of phantom image using different patient position. We evaluated the effective dose(ED) of 23 consecutive patients (M : F = 13:10) who underwent WSS, based on the automatic image pasting method for multiple exposure digital radiography. The Anterior-Posterior position(AP) and Posterior-Anterior position( PA) projection EDs were evaluated based on the PC based Monte Carlo simulation. We measured spine transverse process distance and angulation using DICOM measurement. For all patient, the average ED was 0.069 mSv for AP position and 0.0361 mSv for PA position. AP position calculated double exposure then PA position. For male patient, the average ED was 0.089 mSv(AP) and 0.050 mSv(PA). For female patient, the average ED was 0.0431 mSv(AP) and 0.026 mSv(PA). The transverse process of PA spine image measured 5% higher than AP but angulation of transverse process was no significant differences. In clinical practice, just by change the patient position was conformed to reduce the ED of patient. Therefore we need to redefine of protocol for digital radiography such as WSS, whole spine scanography, effective dose, patient exposure dose, exposure direction, protocol optimization.

  3. Dosimetry in computerized tomography and evaluation of doses in organs in thorax scanning

    International Nuclear Information System (INIS)

    Alonso, Thêssa Cristina

    2016-01-01

    Computed tomography has promoted improvement of the diagnostic process by producing anatomical cut images with high quality and contrast between soft tissues which have very similar absorption of the X-ray beams. The objective of this study is to evaluate the technological park of CT in Brazil correlated with the wide world, and carry out studies of experimental dosimetry to understand the dose distribution feature using phantoms and different methods of measurement of kerma index, as well as perform measures of local doses in sensitive organs. To study the scanner geographic distribution and supply of computed tomography tests in Brazil, a comparison has been made with results found with the specified reference by Brazilian law (Ordinance GM / MS No. 1101, 2002; Resolution RE nº1016, 2006). For dosimetry studies, It was used a standard chest phantom and the anthropomorphic phantom. For image quality evaluation, it was used the CATPHAN-600 phantom. Scans were performed in a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using a pencil ionization chamber, thermoluminescent dosimeters and radiochromic film strips. Sensitive organ shielding devices were evaluated in order to verify their efficiency in organ dose reduction and its influence in the quality of image. Considering Brazilian population, the scanner park showed a greater amount than the minimum parameter recommended by Brazilian law. Dose measurements using three different methods showed the correct procedure of metrological reliability of the measurement system. The findings and conclusions of this study may contribute to the improvement of local practices in Computed Tomography tests, inserted in context of radiological protection in order to define reference levels for optimized diagnosis, and image quality control. (author)

  4. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations

    International Nuclear Information System (INIS)

    Khoury, Helen Jamil; Silveira, Marcia Maria Fonseca da; Couto, Geraldo Bosco Lindoso; Brasileiro, Izabela Vanderley

    2005-01-01

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  5. Evaluation of dose prediction errors and optimization convergence errors of deliverable-based head-and-neck IMRT plans computed with a superposition/convolution dose algorithm

    International Nuclear Information System (INIS)

    Mihaylov, I. B.; Siebers, J. V.

    2008-01-01

    The purpose of this study is to evaluate dose prediction errors (DPEs) and optimization convergence errors (OCEs) resulting from use of a superposition/convolution dose calculation algorithm in deliverable intensity-modulated radiation therapy (IMRT) optimization for head-and-neck (HN) patients. Thirteen HN IMRT patient plans were retrospectively reoptimized. The IMRT optimization was performed in three sequential steps: (1) fast optimization in which an initial nondeliverable IMRT solution was achieved and then converted to multileaf collimator (MLC) leaf sequences; (2) mixed deliverable optimization that used a Monte Carlo (MC) algorithm to account for the incident photon fluence modulation by the MLC, whereas a superposition/convolution (SC) dose calculation algorithm was utilized for the patient dose calculations; and (3) MC deliverable-based optimization in which both fluence and patient dose calculations were performed with a MC algorithm. DPEs of the mixed method were quantified by evaluating the differences between the mixed optimization SC dose result and a MC dose recalculation of the mixed optimization solution. OCEs of the mixed method were quantified by evaluating the differences between the MC recalculation of the mixed optimization solution and the final MC optimization solution. The results were analyzed through dose volume indices derived from the cumulative dose-volume histograms for selected anatomic structures. Statistical equivalence tests were used to determine the significance of the DPEs and the OCEs. Furthermore, a correlation analysis between DPEs and OCEs was performed. The evaluated DPEs were within ±2.8% while the OCEs were within 5.5%, indicating that OCEs can be clinically significant even when DPEs are clinically insignificant. The full MC-dose-based optimization reduced normal tissue dose by as much as 8.5% compared with the mixed-method optimization results. The DPEs and the OCEs in the targets had correlation coefficients greater

  6. Performance evaluation of iterative reconstruction algorithms for achieving CT radiation dose reduction — a phantom study

    Science.gov (United States)

    Dodge, Cristina T.; Tamm, Eric P.; Cody, Dianna D.; Liu, Xinming; Jensen, Corey T.; Wei, Wei; Kundra, Vikas

    2016-01-01

    The purpose of this study was to characterize image quality and dose performance with GE CT iterative reconstruction techniques, adaptive statistical iterative reconstruction (ASiR), and model‐based iterative reconstruction (MBIR), over a range of typical to low‐dose intervals using the Catphan 600 and the anthropomorphic Kyoto Kagaku abdomen phantoms. The scope of the project was to quantitatively describe the advantages and limitations of these approaches. The Catphan 600 phantom, supplemented with a fat‐equivalent oval ring, was scanned using a GE Discovery HD750 scanner at 120 kVp, 0.8 s rotation time, and pitch factors of 0.516, 0.984, and 1.375. The mA was selected for each pitch factor to achieve CTDIvol values of 24, 18, 12, 6, 3, 2, and 1 mGy. Images were reconstructed at 2.5 mm thickness with filtered back‐projection (FBP); 20%, 40%, and 70% ASiR; and MBIR. The potential for dose reduction and low‐contrast detectability were evaluated from noise and contrast‐to‐noise ratio (CNR) measurements in the CTP 404 module of the Catphan. Hounsfield units (HUs) of several materials were evaluated from the cylinder inserts in the CTP 404 module, and the modulation transfer function (MTF) was calculated from the air insert. The results were confirmed in the anthropomorphic Kyoto Kagaku abdomen phantom at 6, 3, 2, and 1 mGy. MBIR reduced noise levels five‐fold and increased CNR by a factor of five compared to FBP below 6 mGy CTDIvol, resulting in a substantial improvement in image quality. Compared to ASiR and FBP, HU in images reconstructed with MBIR were consistently lower, and this discrepancy was reversed by higher pitch factors in some materials. MBIR improved the conspicuity of the high‐contrast spatial resolution bar pattern, and MTF quantification confirmed the superior spatial resolution performance of MBIR versus FBP and ASiR at higher dose levels. While ASiR and FBP were relatively insensitive to changes in dose and pitch, the spatial

  7. Effective dose evaluation for workers assisting new-borns in nuclear medicine procedures

    International Nuclear Information System (INIS)

    Falivene, A.; Gori, C.; Mazzocchi, S.; Targetti, S.; Zatelli, G.

    2002-01-01

    Renal scintigraphy is a very frequent nuclear medicine procedure for new-borns when deemed necessary after prenatal ultrasounds investigation. The procedure requires the physical proximity of workers to the patient, particularly during the examination of new-borns, in order to keep the young patients still. The irradiation of nurses during kidney examination of new-borns has been measured by simulating the examination procedure with an Alderson Rando phantom stuffed with thermoluminescent detectors, positioned near a radioactive source obtained with a tank filled with a 9 9mT c solution. Measurements have been carried out both with and without radiation protection devices positioned on the Rando phantom. Different organ doses have been evaluated. The aim of this analysis is to evaluate the amount of dose reduction that can be achieved by utilising lead aprons, glasses and thyroid collars

  8. Evaluation of the dose distribution for prostate implants using various 125I and 103Pd sources

    International Nuclear Information System (INIS)

    Meigooni, Ali S.; Luerman, Christine M.; Sowards, Keith T.

    2009-01-01

    Recently, several different models of 125 I and 103 Pd brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG-43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of 125 I and 103 Pd sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for 125 I and the Theragenics model 200 seed for 103 Pd using the same implant scheme.

  9. Evaluation of exposure in mammography: limitations of average glandular dose and proposal of a new quantity

    International Nuclear Information System (INIS)

    Geeraert, N.; Bosmans, H.; Klausz, R.; Muller, S.; Bloch, I.

    2015-01-01

    The radiation risk in mammography is traditionally evaluated using the average glandular dose. This quantity for the average breast has proven to be useful for population statistics and to compare exposure techniques and systems. However it is not indicating the individual radiation risk based on the individual glandular amount and distribution. Simulations of exposures were performed for six appropriate virtual phantoms with varying glandular amount and distribution. The individualised average glandular dose (iAGD), i.e. the individual glandular absorbed energy divided by the mass of the gland, and the glandular imparted energy (GIE), i.e. the glandular absorbed energy, were computed. Both quantities were evaluated for their capability to take into account the glandular amount and distribution. As expected, the results have demonstrated that iAGD reflects only the distribution, while GIE reflects both the glandular amount and distribution. Therefore GIE is a good candidate for individual radiation risk assessment. (authors)

  10. Evaluation of ovary dose for woman of childbearing age woman with breast cancer in tomotherapy

    International Nuclear Information System (INIS)

    Lee, Soo Hyeong; Park, Soo Yeon; Choi, Ji Min; Park, Ju Young; Kim, Jong Suk

    2014-01-01

    The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of 64.94±0.84 mGy and 37.64±1.20 mGy in left ovary part and average of 64.38±1.85 mGy and 32.96±1.11 mGy in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required

  11. Evaluation of ovary dose for woman of childbearing age woman with breast cancer in tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hyeong; Park, Soo Yeon; Choi, Ji Min; Park, Ju Young; Kim, Jong Suk [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2014-12-15

    The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of 64.94±0.84 mGy and 37.64±1.20 mGy in left ovary part and average of 64.38±1.85 mGy and 32.96±1.11 mGy in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

  12. Megavoltage cone beam computed tomography: commissioning and evaluation of patient dose

    International Nuclear Information System (INIS)

    Abou-elenein, Hassan S.; Attalla, Ehab M.; Ammar, H.; Eldesoky, Ismail; Farouk, Mohamed; Zaghloul, Mohamed S.

    2011-01-01

    The improvement in conformal radiotherapy techniques enables us to achieve steep dose gradients around the target which allows the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. One of the reasons for this improvement was the implementation of intensity-modulated radio therapy (IMRT) by using linear accelerators fitted with multi-leaf collimator (MLC), Tomo therapy and Rapid arc. In this situation, verification of patient set-up and evaluation of internal organ motion just prior to radiation delivery become important. To this end, several volumetric image-guided techniques have been developed for patient localization, such as Siemens OPTIVUE/MVCB and MVision megavoltage cone beam CT (MV-CBCT) system. Quality assurance for MV-CBCT is important to insure that the performance of the Electronic portal image device (EPID) and MV-CBCT is suitable for the required treatment accuracy. In this work, the commissioning and clinical implementation of the OPTIVUE/MVCB system was presented. The geometry and gain calibration procedures for the system were described. The image quality characteristics of the OPTIVUE/MVCB system were measured and assessed qualitatively and quantitatively, including the image noise and uniformity, low-contrast resolution, and spatial resolution. The image reconstruction and registration software were evaluated. Dose at isocenter from CBCT and the EPID were evaluated using ionization chamber and thermo-luminescent dosimeters; then compared with that calculated by the treatment planning system (TPS- XiO 4.4). The results showed that there are no offsets greater than 1 mm in the flat panel alignment in the lateral and longitudinal direction over 18 months of the study. The image quality tests showed that the image noise and uniformity were within the acceptable range, and that a 2 cm large object with 1% electron density contrast can be detected with the OPTIVUE/MVCB system with 5 monitor units (MU

  13. Evaluation of medium-dose UVA1 phototherapy in localized scleroderma with the cutometer and fast Fourier transform method

    NARCIS (Netherlands)

    de Rie, M. A.; Enomoto, D. N. H.; de Vries, H. J. C.; Bos, J. D.

    2003-01-01

    Purpose: To evaluate the efficacy of medium-dose UVA1 phototherapy in patients with localized scleroderma. Method: A controlled pilot study with medium-dose UVA1 (48 J/cm(2)) was performed. The results were evaluated by means of a skin score and two objective methods for quantifying sclerosis

  14. Evaluation of fluence to dose equivalent conversion factors for high energy radiations, (1)

    International Nuclear Information System (INIS)

    Sato, Osamu; Uehara, Takashi; Yoshizawa, Nobuaki; Iwai, Satoshi; Tanaka, Shun-ichi.

    1992-09-01

    Computer code system and basic data have been investigated for evaluating fluence to dose equivalent conversion factors for photons and neutrons up to 10 GeV. The present work suggested that the conversion factors would be obtained by incorporating effective quality factors of charged particles into the HERMES (High Energy Radiation Monte Carlo Elaborate System) code system. The effective quality factors for charged particles were calculated on the basis of the Q-L relationships specified in the ICRP Publication-60. (author)

  15. Evaluation of low dose ionizing radiation effect on some blood components in animal model

    OpenAIRE

    El-Shanshoury, H.; El-Shanshoury, G.; Abaza, A.

    2016-01-01

    Exposure to ionizing radiation is known to have lethal effects in blood cells. It is predicted that an individual may spend days, weeks or even months in a radiation field without becoming alarmed. The study aimed to discuss the evaluation of low dose ionizing radiation (IR) effect on some blood components in animal model. Hematological parameters were determined for 110 animal rats (divided into 8 groups) pre- and post-irradiation. An attempt to explain the blood changes resulting from both ...

  16. Sensory evaluation of Regina freestone peaches treated with low doses of gamma radiation

    International Nuclear Information System (INIS)

    O'Mahony, M.; Wong, S.Y.; Odbert, N.

    1985-01-01

    Sensory appraisal of low post-harvest gamma irradiation dosing (65-75 Krad) of a single batch of peaches revealed significant differences in aroma and in taste components not associated with sweetness, but only slight differences in firmness and appearance. A panel of practiced judges evaluated irradiated and non-irradiated peaches using a technique of minimal cross-sensory inference. The significant differences in aroma and taste also were detected by untrained judges

  17. A development of computer code for evaluating internal radiation dose through ingestion and inhalation pathways

    International Nuclear Information System (INIS)

    Lee, Jeong Ho; Lee, Chang Woo; Choi, Yong Ho; Chun, Ki Jung; Kim, Kook Chan; Kim, Sang Bok; Kim, Jin Kyu

    1991-07-01

    The computer codes were developed to evaluate internal radiation dose when radioactive isotopes released from nuclear facilities are taken through ingestion and inhalation pathways. Food chain models and relevant data base representing the agricultural and social environment of Korea are set up. An equilibrium model-KFOOD, which can deal with routine releases from a nuclear facility and a dynamic model-ECOREA, which is suitable for the description of acute radioactivity release following nuclear accident. (Author)

  18. Evaluation of internal dose of handlers of radioisotopes and radiopharmaceuticals for medical use

    International Nuclear Information System (INIS)

    Cesar, R.B.P.; Mesquita, C.H. de

    1987-01-01

    The internal dose of workers from IPEN/CNEN-SP (Brazil) is evaluated according to models described by the ICPR-30 (International Comission on Radiological Protection). The workers, monitored by a whole-body counter, are divided into six groups: research and development, routine production, quality control, packaging, radiological protection and maintenance. The results of 970 counting, done in three years, are presented. (M.C.A.) [pt

  19. Quick evaluation of the neutron dose following a criticality accident by measurement of sodium 24 activity

    International Nuclear Information System (INIS)

    Tabardel, R.; Ricourt, A.; Parmentier, N.

    1984-07-01

    In order to quickly sort out the irradiated individuals following a criticality accident, the neutron dose can be evaluated quickly by measuring the sodium-24 activity induced in the human body. The report supplies the information necessary for this evaluation from the response of various detectors of current use in radiation protection. The first part describes the method of evaluation of sodium-24 activity (A) given by the reading (M) of each instrument. The second part describes the method of kerma evaluation from the measured sodium-24 activity. The third part is an experimental application of the method of kerma evaluation from the sodium-24 activity measured in a phantom irradiated in the SILENE reactor flux. The results given by radiation protection instruments are in good agreement with the calculated values for a front exposure and demonstrate the usefulness of measuring the induced sodium-24 activity by radiation protection instruments of current use [fr

  20. Evaluation of the Entrance Surface Dose (ESD and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

    Directory of Open Access Journals (Sweden)

    Vahid Karami

    2017-06-01

    Full Text Available Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patients of both genders referred to anteroposterior (AP projection of pelvic radiography. The radiation dose was directly measured using high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD-GR200. Two TLDs were placed at the center point of the radiation field to measure the ESD of pelvis. Moreover for each patient, 2 TLDs were placed upon each eyelid, 2 TLDs upon each breast, 2 TLDs upon the surface anatomical position of the thyroid gland and finally 2 TLDs at the surface anatomical position of the gonads to measure the received dose. Results The ESD ± standard deviation for AP pelvic radiography was obtained 591.7±76 µGy. Statistically significant difference was obtained between organs located outside and inside of the radiation field with respect to dose received (P

  1. Evaluation on organ dose and image quality of lumber spine radiography using glass dosimeter

    International Nuclear Information System (INIS)

    Kim, Jae Kyeom; Kim, Jeong Koo

    2016-01-01

    The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from 8″×17″ to 14″×17″ by 1″ in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1″ in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1″. Organ dose difference for internal and external of collimator measured 549.8 μGy in the liver and 264.6 μGy in the stomach. There were no significant changes organ dose difference that measured 1,135.1 μG in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than 9″×17″ on AP projection and 10″×17″ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography

  2. SU-F-T-122: 4Dand 5D Proton Dose Evaluation with Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Titt, U; Mirkovic, D; Yepes, P; Liu, A; Peeler, C; Randenyia, S; Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: We evaluated uncertainties in therapeutic proton doses of a lung treatment, taking into account intra-fractional geometry changes, such as breathing, and inter-fractional changes, such as tumor shrinkage and weight loss. Methods: A Monte Carlo study was performed using four dimensional CT image sets (4DCTs) and weekly repeat imaging (5DCTs) to compute fixed RBE (1.1) and variable RBE weighted dose in an actual lung treatment geometry. The MC2 Monte Carlo system was employed to simulate proton energy deposition and LET distributions according to a thoracic cancer treatment plan developed with a 3D-CT in a commercial treatment planning system, as well as in each of the phases of 4DCT sets which were recorded weekly throughout the course of the treatment. A cumulative dose distribution in relevant structures was computed and compared to the predictions of the treatment planning system. Results: Using the Monte Carlo method, dose deposition estimates with the lowest possible uncertainties were produced. Comparison with treatment planning predictions indicates that significant uncertainties may be associated with therapeutic lung dose prediction from treatment planning systems, depending on the magnitude of inter- and intra-fractional geometry changes. Conclusion: As this is just a case study, a more systematic investigation accounting for a cohort of patients is warranted; however, this is less practical because Monte Carlo simulations of such cases require enormous computational resources. Hence our study and any future case studies may serve as validation/benchmarking data for faster dose prediction engines, such as the track repeating algorithm, FDC.

  3. Evaluation of occupational exposure in intraoral radiography; Avaliacao da dose ocupacional em radiografia intraoral

    Energy Technology Data Exchange (ETDEWEB)

    Miguel, Cristiano; Barros, Frieda S.; Rocha, Anna S.P.S.; Godoi, Walmor C., E-mail: miguel_cristianoch@yahoo.com.br, E-mail: saicla@utfpr.edu.br, E-mail: annarocha@yahoo.com, E-mail: walmor.godoi@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Tilly Junior, Joao G., E-mail: joao.tilly@derax.com.br [Universidade Federal do Parana (HC/UFPR), Curitiba, PR (Brazil). Hospital das Clinicas

    2014-07-01

    The intraoral radiography is widely performed in the dental office due to low cost and agility. The doses in intraoral radiology are considered low, however it is known that doses below the threshold for deterministic radiation has the potential to induce stochastic effects. An intraoral radiography has a risk of inducing fatal cancer or serious in order of 1:10,000,000. Besides the patient, the dentist may also be being exposed to radiation during the work with the radiographics practices. The bibliographies demonstrates the lack of information on radiation protection of dentists, however, the occupational dose reduction was observed in radiology over the past 14 years. This work aims to evaluate the effective dose of radiation to which workers can be exposed dentists in dental offices to perform intraoral radiographs. In this context, a study was be conducted between June 2013 and May 2014 with 44 professionals in Curitiba city. For each dentist was given a personal dosimeter to be used for 30 days. During this period, the number of radiographies and the length of the cable triggers of the X-ray equipment was registered and, the dosimeter´s dose was read. It was observed that the cables triggers meet regulatory standards and allow dentists to get the mean minimum distance of two meters from the radiation source in 93% of cases. Through analysis of the doses, it was concluded that occupational exposures of these workers are within the recommended threshold by regulatory 453/1998 of the Ministry of Health from Brazil. (author)

  4. Preparation and the Biopharmaceutical Evaluation for the Metered Dose Transdermal Spray of Dexketoprofen

    Science.gov (United States)

    Luo, Huafei; Zhu, Zhuangzhi; Wu, Yubo; Luo, Jing; Wang, Hao

    2014-01-01

    The objective of the present work was to develop a metered dose transdermal spray (MDTS) formulation for transdermal delivery of dexketoprofen (DE). DE release from a series of formulations was assessed in vitro. Various qualitative and quantitative parameters like spray pattern, pump seal efficiency test, average weight per metered dose, and dose uniformity were evaluated. The optimized formulation with good skin permeation and an appropriate drug concentration and permeation enhancer (PE) content was developed incorporating 7% (w/w, %) DE, 7% (v/v, %) isopropyl myristate (IPM), and 93% (v/v, %) ethanol. In vivo pharmacokinetic study indicated that the optimized formulation showed a more sustainable plasma-concentration profile compared with the Fenli group. The antiinflammatory effect of DE MDTS was evaluated by experiments involving egg-albumin-induced paw edema in rats and xylene-induced ear swelling in mice. Acetic acid-induced abdominal constriction was used to evaluate the anti-nociceptive actions of DE MDTS. Pharmacodynamic studies indicated that the DE MDTS has good anti-inflammatory and anti-nociceptive activities. Besides, skin irritation studies were performed using rat as an animal model. The results obtained show that the MDTS can be a promising and innovative therapeutic system used in transdermal drug delivery for DE. PMID:24660066

  5. Preparation and the Biopharmaceutical Evaluation for the Metered Dose Transdermal Spray of Dexketoprofen

    Directory of Open Access Journals (Sweden)

    Wangding Lu

    2014-01-01

    Full Text Available The objective of the present work was to develop a metered dose transdermal spray (MDTS formulation for transdermal delivery of dexketoprofen (DE. DE release from a series of formulations was assessed in vitro. Various qualitative and quantitative parameters like spray pattern, pump seal efficiency test, average weight per metered dose, and dose uniformity were evaluated. The optimized formulation with good skin permeation and an appropriate drug concentration and permeation enhancer (PE content was developed incorporating 7% (w/w, % DE, 7% (v/v, % isopropyl myristate (IPM, and 93% (v/v, % ethanol. In vivo pharmacokinetic study indicated that the optimized formulation showed a more sustainable plasma-concentration profile compared with the Fenli group. The antiinflammatory effect of DE MDTS was evaluated by experiments involving egg-albumin-induced paw edema in rats and xylene-induced ear swelling in mice. Acetic acid-induced abdominal constriction was used to evaluate the anti-nociceptive actions of DE MDTS. Pharmacodynamic studies indicated that the DE MDTS has good anti-inflammatory and anti-nociceptive activities. Besides, skin irritation studies were performed using rat as an animal model. The results obtained show that the MDTS can be a promising and innovative therapeutic system used in transdermal drug delivery for DE.

  6. Evaluation of doses given to foetus in diagnostic radiology in Israel

    International Nuclear Information System (INIS)

    Schlesinger, T.; Donagi, A.; Karpinovitz, A.

    1975-01-01

    Among the various groups exposed to diagnostic radiation, pregnant women, during the first months of pregnancy, require special attention, because of the high sensitivity of the developing foetus to ionizing radiation. In light of this sensitivity, special limitations were adopted in different countries, concerning female X-ray technicians in the reproductive age. However, it frequently happens that a pregnant woman is irradiated during the first months of pregnancy, due to the fact that neither she nor the attending physician is aware that she is pregnant. Many times, after this fact is realized, physicists are asked to ''reconstruct'' the radiographs in order to evaluate the foetus dose. The purpose of this ''reconstruction'' is to determine whether an abortion is to be performed. The present work constitutes the first stage of a research desianed to provide the radiologist with typical Israeli data, which he could use for evaluating the order of magnitude of the foetus dose. The purpose of this ''preliminary evaluation'' carried out by the radiologist is to determine whether the foetus dose is of such a magnitude justifying the performance of a specific ''reconstruction test'' or not. (B.G.)

  7. Evaluation of the absorbed dose to the lungs due to Xe133 and Tc99m (MAA)

    International Nuclear Information System (INIS)

    Vazquez A, M.; Murillo C, F.; Castillo D, C.; Sifuentes D, Y.; Sanchez S, P.; Rojas P, E.; Marquez P, F.

    2015-10-01

    The absorbed dose in lungs of an adult patient has been evaluated using the biokinetics of radiopharmaceuticals containing Xe 133 or Tc 99m (MAA). The absorbed dose was calculated using the MIRD formalism, and the Cristy-and Eckerman lungs model. The absorbed dose in the lungs due to 133 Xe is 0.00104 mGy/MBq. Here, the absorbed dose due to remaining tissue, included in the 133 Xe biokinetics is not significant. The absorbed dose in the lungs, due Tc 99m (MAA), is 0.065 mGy/MBq. Approximately, 4.6% of the absorbed dose is due to organs like liver, kidneys, bladder, and the rest of tissues, included in the Tc 99m biokinetics. Here, the absorbed dose is very significant to be overlooked. The dose contribution is mainly due to photons emitted by the liver. (Author)

  8. Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach

    International Nuclear Information System (INIS)

    Sarrabay, A.; Hilmi, C.; Tinwell, H.; Schorsch, F.; Pallardy, M.; Bars, R.; Rouquié, D.

    2015-01-01

    ABSTRACT: The dose–response characterization of endocrine mediated toxicity is an on-going debate which is controversial when exploring the nature of the dose–response curve and the effect at the low-end of the curve. To contribute to this debate we have assessed the effects of a wide range of dose levels of the antiandrogen flutamide (FLU) on 7-week male Wistar rats. FLU was administered by oral gavage at doses of 0, 0.001, 0.01, 0.1, 1 and 10 mg/kg/day for 28 days. To evaluate the reproducibility, the study was performed 3 times. The molecular initiating event (MIE; AR antagonism), the key events (LH increase, Leydig cell proliferation and hyperplasia increases) and associated events involved in the mode of action (MOA) of FLU induced testicular toxicity were characterized to address the dose response concordance. Results showed no effects at low doses (< 0.1 mg/kg/day) for the different key events studied. The histopathological changes (Leydig cell hyperplasia) observed at 1 and 10 mg/kg/day were associated with an increase in steroidogenesis gene expression in the testis from 1 mg/kg/day, as well as an increase in testosterone blood level at 10 mg/kg/day. Each key event dose–response was in good concordance with the MOA of FLU on the testis. From the available results, only monotonic dose–response curves were observed for the MIE, the key events, associated events and in effects observed in other sex related tissues. All the results, so far, show that the reference endocrine disruptor FLU induces threshold effects in a standard 28-day toxicity study on adult male rats. - Highlights: • Dose–response characterization of endocrine mediated toxicity is an on-going debate. • A wide range of dose levels of flutamide was evaluated on young adult male rats. • Flutamide induces threshold effects using on standard and molecular tools.

  9. Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach

    Energy Technology Data Exchange (ETDEWEB)

    Sarrabay, A. [INSERM, Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry (France); UniverSud, INSERM, UMR-996 “Inflammation, Chemokines and Immunopathology”, Châtenay-Malabry (France); Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Hilmi, C.; Tinwell, H.; Schorsch, F. [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Pallardy, M. [INSERM, Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry (France); UniverSud, INSERM, UMR-996 “Inflammation, Chemokines and Immunopathology”, Châtenay-Malabry (France); Bars, R. [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Rouquié, D., E-mail: david.rouquie@bayer.com [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France)

    2015-12-15

    ABSTRACT: The dose–response characterization of endocrine mediated toxicity is an on-going debate which is controversial when exploring the nature of the dose–response curve and the effect at the low-end of the curve. To contribute to this debate we have assessed the effects of a wide range of dose levels of the antiandrogen flutamide (FLU) on 7-week male Wistar rats. FLU was administered by oral gavage at doses of 0, 0.001, 0.01, 0.1, 1 and 10 mg/kg/day for 28 days. To evaluate the reproducibility, the study was performed 3 times. The molecular initiating event (MIE; AR antagonism), the key events (LH increase, Leydig cell proliferation and hyperplasia increases) and associated events involved in the mode of action (MOA) of FLU induced testicular toxicity were characterized to address the dose response concordance. Results showed no effects at low doses (< 0.1 mg/kg/day) for the different key events studied. The histopathological changes (Leydig cell hyperplasia) observed at 1 and 10 mg/kg/day were associated with an increase in steroidogenesis gene expression in the testis from 1 mg/kg/day, as well as an increase in testosterone blood level at 10 mg/kg/day. Each key event dose–response was in good concordance with the MOA of FLU on the testis. From the available results, only monotonic dose–response curves were observed for the MIE, the key events, associated events and in effects observed in other sex related tissues. All the results, so far, show that the reference endocrine disruptor FLU induces threshold effects in a standard 28-day toxicity study on adult male rats. - Highlights: • Dose–response characterization of endocrine mediated toxicity is an on-going debate. • A wide range of dose levels of flutamide was evaluated on young adult male rats. • Flutamide induces threshold effects using on standard and molecular tools.

  10. Evaluation of patient dose in imaging using a cone-beam CT dosimetry by X-ray films for radiotherapeutic dose

    International Nuclear Information System (INIS)

    Yoshida, Yuri; Morita, Yasuhiko; Honda, Eiichi; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2008-01-01

    A limited cone-beam X-ray CT (3DX multi-image micro CT; 3DX-FPD) is widely used in dentistry because it provides a lower cost, smaller size, and higher spatial resolution than a CT for medicine. Our recent research suggested that the patient dose of 3DX-FPD was less than 7/10 of that of CT, and it was several to 10 times more than that of dental or panoramic radiography. The purpose of this study was to evaluate the spatial dose distribution from 3DX-FPD and to estimate the influence of dose by positioning of the region of interest. Dosimetry of the organs and the tissues was performed using an anthropomorphic Alderson Rando phantom and X-ray films for measurement of radiotherapeutic dose. Measurements of dose distribution were performed using a cylinder-type tank of water made of acrylic resin imitating the head and X-ray films. The results are summarized as follows: The dose was higher as the ratio of the air region included in the region of interest increased. The dose distribution was not homogeneous and the dose was highest in the skin region. The dose was higher for several seconds after the beginning of exposure. It was concluded that patient positioning, as well as exposure conditions including the size of the exposure field and tube current, could greatly influence the patient dose in 3DX-FPD. In addition, it is necessary to consider the influence of image quality for the treatment of dental implants. (author)

  11. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    Science.gov (United States)

    Anderson, Danielle; Siegbahn, E. Albert; Fallone, B. Gino; Serduc, Raphael; Warkentin, Brad

    2012-05-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm2 microbeam array in each phantom, as well as a 16 × 16 mm2 array in the 8 cm cat head, and a 32 × 32 mm2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2-49 (mouse) and 2-46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2-87% and 33-96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this study

  12. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Anderson, Danielle; Fallone, B Gino; Warkentin, Brad; Siegbahn, E Albert; Serduc, Raphael

    2012-01-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm 2 microbeam array in each phantom, as well as a 16 × 16 mm 2 array in the 8 cm cat head, and a 32 × 32 mm 2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2–49 (mouse) and 2–46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2–87% and 33–96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this

  13. Scattering factor evaluation for internal dose assessment due to 60Co

    International Nuclear Information System (INIS)

    Gautam, Y.P.; Kumar, A.; Sharma, S.; Sharma, A.K.; Dube, B.; Hegde, A.G.

    2008-01-01

    Guidelines for the assessment of internal doses from monitoring suggest default measurement of uncertainties (i.e. lognormal scattering factor, SF) to be used for different types of monitoring data. In this paper, SF values have been evaluated for internal contamination due to 60 Co in two cases using whole body counting data. SF values of 1.04 and 1.03 were obtained for case I and II respectively while SF value of 1.03 was obtained using bioassay data for case I. SF evaluated is in good agreement with the default values given by IDEAS guidelines. (author)

  14. Evaluation of mammography equipment performance, dose and image quality in five Latin American countries

    Science.gov (United States)

    Brandan, M.-E.; Ruiz-Trejo, C.; Caspani, C. E. M.; Fleitas, I.; de-la-Mora, R.; Miranda, A. A.; Plazas, M.-C.; Betancourt, C.-M.; Borras, C.

    2001-10-01

    Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin American countries. Its aim is to correlate quality indicators of radiology services with the accuracy of the radiological interpretation as determined by a panel of radiology experts. We present preliminary results from mammographic imaging facilities. Evaluation of the equipment performance and dose measurements in 21 mammographic units show that, on the average, 75% of the units comply with recommendations issued by various organizations. An independent evaluation of the quality of the clinical images show strong variations among the different radiological services.

  15. Evaluation of mammography equipment performance, dose and image quality in five Latin American countries

    International Nuclear Information System (INIS)

    Brandan, M.-E.; Ruiz-Trejo, C.; Caspani, C. E. M.; Fleitas, I.; Mora, R. de la; Miranda, A. A.; Plazas, M.-C.; Betancourt, C.-M.; Borras, C.

    2001-01-01

    Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin American countries. Its aim is to correlate quality indicators of radiology services with the accuracy of the radiological interpretation as determined by a panel of radiology experts. We present preliminary results from mammographic imaging facilities. Evaluation of the equipment performance and dose measurements in 21 mammographic units show that, on the average, 75% of the units comply with recommendations issued by various organizations. An independent evaluation of the quality of the clinical images show strong variations among the different radiological services

  16. Difficulties in teaching electromagnetism: an eight year experience at Pierre and Marie Curie University

    Directory of Open Access Journals (Sweden)

    H. Roussel

    2012-07-01

    Full Text Available We will begin by outlining the details of how electromagnetics are taught in the  electrical engineering program offered at Pierre and Marie Curie University (a French example from the undergraduate to the Masters degree levels.  We will also discuss how our methods are and should be adapted to teach waves propagation without discouraging students.

  17. The Marie Curie Actions at CERN – reaching out beyond particle physics and Europe

    CERN Document Server

    EU Projects Office

    2014-01-01

    The European Commission’s Marie Curie Actions have been a pillar of the EU Framework Programmes for several decades as a means of promoting career development and enhancing mobility of researchers in Europe. This corresponds nicely to one of CERN’s main missions: to train the next generation of scientists and engineers.   The European Commissioner for Education, Culture, Multilingualism, Sport, Media and Youth, Androulla Vassiliou (centre) met the Marie Curie Fellows on her visit to CERN in April 2013. CERN has been pleased to be a major player in the Marie Curie Actions under the Sixth and Seventh Framework Programmes (FP6 from 2002 to 2006 and FP7 from 2007 to 2013), being one of the most successful participants in Europe. Under FP7, CERN was ranked first in Switzerland and fifth in Europe against stiff competition in terms of overall funding. Participation was in all of the Marie Curie Actions: Initial Training Networks, Industry-Academia Partnership Pathways, IRSES, CO...

  18. Going to School with Madame Curie and Mr. Einstein: Gender Roles in Children's Science Biographies

    Science.gov (United States)

    Owens, Trevor

    2009-01-01

    One of the first places children encounter science and scientists is children's literature. Children's books about science and scientists have, however, received limited scholarly attention. By exploring the history of children's biographies of Marie Curie and Albert Einstein, the two most written about scientist in children's literature, this…

  19. Marie Curie, les femmes et la science, d'hier à aujourd'hui - English

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Marie Curie, les femmes et la science, d'hier à aujourd'hui Conférence par Hélène Langevin-Joliot Avec la participation de l'Echo du Reculet de Thoiry. L'enregistrement et la liste d'attente sont déjà complets... Mais il n'est pas rare que des personnes réservent et ne viennent pas. Nous réassignerons les places libérées selon la règle "premier arrivé, premier inscrit". Nous envisageons la possibilité de faire un webcast de la conférence. Plus d'information bientôt. Hélène Langevin-Joliot, directrice de recherche émérite en physique nucléaire fondamentale au CNRS à Orsay, est aussi la fille de Frédéric et Irène Joliot-Curie (prix Nobel de chimie en 1935) et la petite-fille de Pierre Curie (prix Nobel de physique en 1903) et de Marie Curie (prix Nobel de physique en 1903 et prix Nobel de chimie en 1911). Hélène Langevin-Joliot nous parlera de sa vie scientifique, de l’histoire extraordinaire de sa famille et en particulier du rôle des ...

  20. Marie Curie, les femmes et la science, d'hier à aujourd'hui

    CERN Multimedia

    CERN. Geneva; Mariotti, Chiara; Vicinanza, Domenico

    2017-01-01

    Marie Curie, les femmes et la science, d'hier à aujourd'hui Conférence par Hélène Langevin-Joliot Avec la participation de l'Echo du Reculet de Thoiry. L'enregistrement et la liste d'attente sont déjà complets... Mais il n'est pas rare que des personnes réservent et ne viennent pas. Nous réassignerons les places libérées selon la règle "premier arrivé, premier inscrit". Au vu de la forte demande, la conférence sera également disponible en vidéoconférence : lien d'accès "webcast" disponible en bas de cette page. Hélène Langevin-Joliot, directrice de recherche émérite en physique nucléaire fondamentale au CNRS à Orsay, est aussi la fille de Frédéric et Irène Joliot-Curie (prix Nobel de chimie en 1935) et la petite-fille de Pierre Curie (prix Nobel de physique en 1903) et de Marie Curie (prix Nobel de physique en 1903 et prix Nobel de chimie en 1911). Hélène Langevin-Joliot nous parlera de sa vie scientifique, de l’histoire extraordinai...

  1. Pressure dependence of Curie temperature and resisitvity in complex Heusler alloys

    Czech Academy of Sciences Publication Activity Database

    Bose, S. K.; Kudrnovský, Josef; Drchal, Václav; Turek, I.

    2011-01-01

    Roč. 84, č. 17 (2011), 174422/1-174422/8 ISSN 1098-0121 R&D Projects: GA ČR GA202/09/0775 Institutional research plan: CEZ:AV0Z10100520 Keywords : Curie temperature * resistivity * Heusler alloys * hydrostatic pressure * first-principles Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  2. Near-Curie magnetic anomaly at the Ni/C interface observed by Electron Holography

    DEFF Research Database (Denmark)

    Ferrari, Loris; Matteucci, Giorgio; Schofield, Marvin A

    2010-01-01

    We analyze with electron holography carried out in a transmission electron microscope the near-Curie behavior of magnetism at the edge of a Nickel thin film coated with Carbon. In-situ experiments with finely controlled variations of the sample temperature reveal an anomaly in the ferromagnetic...

  3. Computational and human observer image quality evaluation of low dose, knowledge-based CT iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Eck, Brendan L.; Fahmi, Rachid; Miao, Jun [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Brown, Kevin M.; Zabic, Stanislav; Raihani, Nilgoun [Philips Healthcare, Cleveland, Ohio 44143 (United States); Wilson, David L., E-mail: dlw@case.edu [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and Department of Radiology, Case Western Reserve University, Cleveland, Ohio 44106 (United States)

    2015-10-15

    Purpose: Aims in this study are to (1) develop a computational model observer which reliably tracks the detectability of human observers in low dose computed tomography (CT) images reconstructed with knowledge-based iterative reconstruction (IMR™, Philips Healthcare) and filtered back projection (FBP) across a range of independent variables, (2) use the model to evaluate detectability trends across reconstructions and make predictions of human observer detectability, and (3) perform human observer studies based on model predictions to demonstrate applications of the model in CT imaging. Methods: Detectability (d′) was evaluated in phantom studies across a range of conditions. Images were generated using a numerical CT simulator. Trained observers performed 4-alternative forced choice (4-AFC) experiments across dose (1.3, 2.7, 4.0 mGy), pin size (4, 6, 8 mm), contrast (0.3%, 0.5%, 1.0%), and reconstruction (FBP, IMR), at fixed display window. A five-channel Laguerre–Gauss channelized Hotelling observer (CHO) was developed with internal noise added to the decision variable and/or to channel outputs, creating six different internal noise models. Semianalytic internal noise computation was tested against Monte Carlo and used to accelerate internal noise parameter optimization. Model parameters were estimated from all experiments at once using maximum likelihood on the probability correct, P{sub C}. Akaike information criterion (AIC) was used to compare models of different orders. The best model was selected according to AIC and used to predict detectability in blended FBP-IMR images, analyze trends in IMR detectability improvements, and predict dose savings with IMR. Predicted dose savings were compared against 4-AFC study results using physical CT phantom images. Results: Detection in IMR was greater than FBP in all tested conditions. The CHO with internal noise proportional to channel output standard deviations, Model-k4, showed the best trade-off between fit

  4. Evaluation of patient absorbed dose in a PET-CT test

    Energy Technology Data Exchange (ETDEWEB)

    Guerra P, F.; Mourao F, A. P. [Federal University of Minas Gerais, Department of Nuclear Engineering, Av. Antonio Carlos 6627, CEP 31270-901, Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P. C., E-mail: fgpaiva92@gmail.com [Federal University of Minas Gerais, Medical School, Av. Prof. Alfredo Balena 190, CEP 30123970, Santa Efigenia, Belo Horizonte, Minas Gerais (Brazil)

    2017-10-15

    Images of PET-CT has important diagnostic applications, especially in oncology. This equipment allows overlapping of functional images obtained from the administration of radionuclides and anatomical, generated by X-rays. The PET-CT technique may generate higher doses in patients due to the fact that two diagnostic modalities are used in a single examination. A whole body CT scan is performed and in sequence, a capture of the signal generated by the photons emitted is done. In this study, the absorbed and effective doses generated by the CT scan and incorporated by the administration of the radionuclide were evaluated in 19 organs. To evaluate the CT dose, 32 radiochromic film strips were correctly positioned into the anthropomorphic male phantom. The CT protocol performed was whole-body scanning and a high-resolution lung scan. This protocol is currently used in most services. The calculation of the effective dose from the injected activity in the patient was performed using the ICRP 106 Biokinetic model (ICRP 106, 2008). The activity to be injected may vary according to the patients body mass and with the sensitivity of the detector. The mass of the simulator used is 73.5 kg, then the simulation with and injected activity of 244.76 MBq was used. It was observed that 87.4% of the effective dose in examination PET/CT comes from the CT scans, being 63.8% of the whole body scan and 23.6% of high resolution lung scan. Using activity of 0.09 mCi x kg {sup 18}F-FDG radiopharmaceutical contributes only 12.6% of the final effective dose. As a conclusion, it was observed that the dose in patients submitted to the {sup 18}F-FDG PET-CT examination is high, being of great value efforts for its reduction, such as the use of appropriate image acquisition techniques and promoting the application of the principle of optimization of practice. (Author)

  5. Evaluation of axillary dose coverage following whole breast radiotherapy: Variation with the breast volume and shape

    International Nuclear Information System (INIS)

    Aguiar, Artur; Gomes Pereira, Helena; Azevedo, Isabel; Gomes, Luciano

    2015-01-01

    Objective: To evaluate the axillary dose coverage in patients treated with tridimensional whole breast radiotherapy (3D-WBRT), according to the breast volume and shape in treatment position. Background: Several studies have demonstrated an insufficient dose contribution to the axillary levels, using 3D-WBRT, remaining unclear whether the breast volume and shape can influence it. Materials and methods: We retrospectively delineated the axillary levels on planning CT-images of 100 patients, treated with 3D-WBRT along 2012 in our institution. To estimate the shape we established an anatomic CT-based interval, defined as the Thoracic Extent (TE). The breast volume matched its CTV. Mean dose levels and V95 (volume receiving at least 95% of the prescribed dose) were evaluated. Results: Mean axillary level I (A1), II (A2) and III (A3) volume was 56.1 cc, 16.5 cc and 18.9 cc, respectively, and mean doses were 43.9 Gy, 38.6 Gy and 19.5 Gy. For breast volumes of <800 cc, 800–999 cc, 1000–1199 cc and >1200 cc, mean A1 V95 was 38%, 51%, 61.2% and 57.2% whereas median A2 V95 was 8.3%, 13.4%, 19.4% and 28% respectively. Regarding shape, where the breast relative position to the TE was categorized in intervals between 31% and 40%, 41% and 50%, 51% and 60%, and 61% and 70%, mean A1 V95 was 38.7%, 43.1%, 51.1% and 77.3% whereas mean A2 V95 was 6.1%, 11.2%, 17.1% and 37% respectively. Conclusions: We observed inadequate dose coverage to all axillary levels, even after applying a sub-analysis accounting for different breast volumes and shapes. Although higher doses were associated with the more voluminous and pendulous breasts, axillary coverage with 3D-WBRT seems to be inefficient, regardless of the breast morphology

  6. Evaluation of dose-volume histograms after prostate seed implantation. 4-year experience

    International Nuclear Information System (INIS)

    Hoinkis, C.; Lehmann, D.; Winkler, C.; Herrmann, T.; Hakenberg, O.W.; Wirth, M.P.

    2004-01-01

    Background and purpose: permanent interstitial brachytherapy by seed implantation is a treatment alternative for low-volume low-risk prostate cancer and a complex interdisciplinary treatment with a learning curve. Dose-volume histograms are used to assess postimplant quality. The authors evaluated their learning curve based on dose-volume histograms and analyzed factors influencing implantation quality. Patients and methods: since 1999, 38 patients with a minimum follow-up of 6 months were treated at the authors' institution with seed implantation using palladium-103 or iodine-125, initially using the preplan method and later real-time planning. Postimplant CT was performed after 4 weeks. The dose-volume indices D90, V100, V150, the D max of pre- and postplans, and the size and position of the volume receiving the prescribed dose (high-dose volume) of the postplans were evaluated. In six patients, postplan imaging both by CT and MRI was used and prostate volumes were compared with preimplant transrectal ultrasound volumes. The first five patients were treated under external supervision. Results: patients were divided into three consecutive groups for analysis of the learning curve (group 1: n = 5 patients treated under external supervision; group 2: n = 13 patients; group 3: n = 20 patients). D90 post for the three groups were 79.3%, 74.2%, and 99.9%, the V100 post were 78.6%, 73.5%, and 88.2%, respectively. The relationship between high-dose volume and prostate volume showed a similar increase as the D90, while the relationship between high-dose volume lying outside the prostate and prostate volume remained constant. The ratio between prostate volumes from transrectal ultrasound and CT imaging decreased with increasing D90 post , while the preplanning D90 and V100 remained constant. The different isotopes used, the method of planning, and the implanted activity per prostate volume did not influence results. Conclusion: a learning curve characterized by an increase

  7. Evaluation of Skin Dose and Image Quality on Cone Beam Computed Tomography

    International Nuclear Information System (INIS)

    Ahn, Jong Ho; Hong, Chae Seon; Kim, Jin Man; Jang, Jun Young

    2008-01-01

    Cone-beam CT using linear accelerator attached to on-board imager is a image guided therapy equipment. Because it is to check the patient's set-up error, correction, organ and target movement. But imaging dose should be cause of the secondary cancer when taking a image. The aim of this study is investigation of appropriate cone beam CT scan mode to compare and estimate the image quality and skin dose. Measurement by Thermoluminescence dosimeter (TLD-100, Harshaw) with using the Rando phantom are placed on each eight sites in separately H and N, thoracic, abdominal section. each 4 methods of scan modes of are measured the for skin dose in three time. Subsequently, obtained average value. Following image quality QA protocol of equipment manufacturers using the catphan 504 phantom, image quality of each scan mode is compared and analyzed. The results of the measured skin dose are described in here. The skin dose of Head and Neck are measured mode A: 8.96 cGy, mode B: 4.59 cGy, mode C: 3.46 cGy mode D: 1.76 cGy and thoracic mode A: 9.42 cGy, mode B: 4.58 cGy, mode C: 3.65 cGy, mode D: 1.85 cGy, and abdominal mode A: 9.97 cGy, mode B: 5.12 cGy, mode C: 4.03 cGy, mode D: 2.21 cGy. Approximately, dose of mode B are reduced 50%, mode C are reduced 60%, mode D are reduced 80% a point of reference dose of mode A. the results of analyzed HU reproducibility, low contrast resolution, spatial resolution (high contrast resolution), HU uniformity in evaluation item of image quality are within the tolerance value by recommended equipment manufacturer in all scan mode. Maintaining the image quality as well as reducing the image dose are very important in cone beam CT. In the result of this study, we are considered when to take mode A when interested in soft tissue. And we are considered to take mode D when interested in bone scan and we are considered to take mode B, C when standard scan. Increasing secondary cancer risk due to cone beam CT scan should be reduced by low m

  8. The accuracy evaluation according to dose delivery interruption and restart for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hyung; Bae, Sun Myung; Kwak, Jung Won; Kang, Tae Young; Bck, Geum Mun [Dept. of Radiation Oncology, Asan Medical Center, Seoul(Korea, Republic of)

    2013-03-15

    The accurate movement of gantry rotation, collimator and correct application of dose rate are very important to approach the successful performance of Volumetric Modulated Arc Therapy (VMAT), because it is tightly interlocked with a complex treatment plan. The interruption and restart of dose delivery, however, are able to occur on treatment by various factors of a treatment machine and treatment plan. If unexpected problems of a treat machine or a patient interrupt the VMAT, the movement of treatment machine for delivering the remaining dose will be restarted at the start point. In this investigation, We would like to know the effect of interruptions and restart regarding dose delivery at VMAT. Treatment plans of 10 patients who had been treated at our center were used to measure and compare the dose distribution of each VMAT after converting to a form of digital image and communications in Medicine (DICOM) with treatment planning system (Eclipse V 10.0, Varian, USA). We selected the 6 MV photon energy of Trilogy (Varian, USA) and used OmniPro I'mRT system (V 1.7b, IBA dosimetry, Germany) to analyze the data that were acquired through this measurement with two types of interruptions four times for each case. The door interlock and the beam-off were used to stop and then to restart the dose delivery of VMAT. The gamma index in OmniPro I'mRT system and T-test in Microsoft Excel 2007 were used to evaluate the result of this investigation. The deviations of average gamma index in cases with door interlock, beam-off and without interruption on VMAT are 0.141, 0.128 and 0.1. The standard deviations of acquired gamma values are 0.099, 0.091, 0.071 and The maximum gamma value in each case is 0.413, 0.379, 0.286, respectively. This analysis has a 95-percent confidence level and the P-value of T-test is under 0.05. Gamma pass rate (3%, 3 mm) is acceptable in all of measurements. As a result, We could make sure that the interruption of this investgation are not

  9. New technology development for radiation dose measurement and evaluation based on the operational quantity

    International Nuclear Information System (INIS)

    Kim, Jang Lyul; Kim, B. H.; Lee, J. I.; Lim, K. S.; Song, M. Y.; Joo, G. S.; Kim, S. I.; Chang, I. S.

    2012-04-01

    · Development of optically stimulated luminescence (OSL) technique for multi-purpose radiation dosimetry - Development of a semi-automatic type OSL measurement system · Number of sample holders: 10 ea · Development of a built-in type reference radiation irradiation system using 50 kV-1 mA X-rays of the maximum dose rate of 230 mGy/s - Development of an automatic diameter control system and crystal growth system for making a new OSL material: LiMgF 3 : X, LiAlO 2 : C - Development of a procedure of retrospective accident dosimetry · Establishment of Practical Technology for Internal Dose Assessment - Development of the technology to the internal dose assessment for an injection of radionuclides and intercomparison on the evaluation results of the committed effective dose between the estimators of Korea · Construction of workplace monitoring technique by quantification of neutron fields - Preparation of the neutron spectra DB of various neutron fields and production of those dosimetric data: 29 kinds of neutron fields using a thermal neutron irradiator, a proton accelerator and a neutron generator - Neutron monitoring procedure at workplace using neutron fluence spectra

  10. Evaluation of patients radiation dose from computed tomography during lower peripheral angiography procedure

    International Nuclear Information System (INIS)

    Khlafallah, Leena Ahmed Ali

    2015-09-01

    The purpose of this study was to evaluate patient radiation doses in lower peripheral angiography CT examinations in Sudan. Survey was conducted in four major hospitals which almost carry out lower peripheral angiography procedures in Sudan at the time of study. All hospitals were equipped with 64 slices multi detectors CT from Toshiba (Japan). The total number of patients was 74. Information on patient's genders and ages, exposure technique factors and radiation dose were collected. The procedures performed in multi phases, up to five phases covering part of the abdomen region, which can make patients exposure reasonably high. CTDI values in the different phases ranged between (13-30) mGy. The total DLP in the four hospitals were 6888.75, 5065.05, 6608.88 and 5754.9 mGy.cm. This study provided first survey for patient dose during lower peripheral angiography procedures in Sudan. Taking into account that the CT machines were similar: the variation between patient's DLP and CTDI values in the different hospitals indicated the need of optimization of radiation protection. Staff training and awareness on factors affecting patient dose are essential.(Author)

  11. Dosimetric evaluation of photon dose calculation under jaw and MLC shielding

    International Nuclear Information System (INIS)

    Fogliata, A.; Clivio, A.; Vanetti, E.; Nicolini, G.; Belosi, M. F.; Cozzi, L.

    2013-01-01

    Purpose: The accuracy of photon dose calculation algorithms in out-of-field regions is often neglected, despite its importance for organs at risk and peripheral dose evaluation. The present work has assessed this for the anisotropic analytical algorithm (AAA) and the Acuros-XB algorithms implemented in the Eclipse treatment planning system. Specifically, the regions shielded by the jaw, or the MLC, or both MLC and jaw for flattened and unflattened beams have been studied.Methods: The accuracy in out-of-field dose under different conditions was studied for two different algorithms. Measured depth doses out of the field, for different field sizes and various distances from the beam edge were compared with the corresponding AAA and Acuros-XB calculations in water. Four volumetric modulated arc therapy plans (in the RapidArc form) were optimized in a water equivalent phantom, PTW Octavius, to obtain a region always shielded by the MLC (or MLC and jaw) during the delivery. Doses to different points located in the shielded region and in a target-like structure were measured with an ion chamber, and results were compared with the AAA and Acuros-XB calculations. Photon beams of 6 and 10 MV, flattened and unflattened were used for the tests.Results: Good agreement between calculated and measured depth doses was found using both algorithms for all points measured at depth greater than 3 cm. The mean dose differences (±1SD) were −8%± 16%, −3%± 15%, −16%± 18%, and −9%± 16% for measurements vs AAA calculations and −10%± 14%, −5%± 12%, −19%± 17%, and −13%± 14% for Acuros-XB, for 6X, 6 flattening-filter free (FFF), 10X, and 10FFF beams, respectively. The same figures for dose differences relative to the open beam central axis dose were: −0.1%± 0.3%, 0.0%± 0.4%, −0.3%± 0.3%, and −0.1%± 0.3% for AAA and −0.2%± 0.4%, −0.1%± 0.4%, −0.5%± 0.5%, and −0.3%± 0.4% for Acuros-XB. Buildup dose was overestimated with AAA, while Acuros-XB gave

  12. Evaluation of radiation dose during the percutaneous angioplasty for arteriovenous shunt assembling

    International Nuclear Information System (INIS)

    Ting, Chien-Yi; Wu, Wen-Shiann; Tang, Kuo-Ting; Wang, Hsin-Ell; Lin, Chun-Chih

    2017-01-01

    radiation exposure to the patient during the PTA for the arteriovenous shunt assembling, which is suggested should be applied to the current cardiac catheterization. - Highlights: • Dose reduction in patient and operator during PTA was evaluated with a RADPAD drape. • Dose at patient's hands apparently reduced after shielded with the RADPAD in PTA. • A RADPAD shield apparently reduced patient's dose in PTA.

  13. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    Energy Technology Data Exchange (ETDEWEB)

    Rawl, Richard R [ORNL; Scofield, Patricia A [ORNL; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low

  14. Evaluation of the effect of patient dose from cone beam computed tomography on prostate IMRT using Monte Carlo simulation.

    Science.gov (United States)

    Chow, James C L; Leung, Michael K K; Islam, Mohammad K; Norrlinger, Bernhard D; Jaffray, David A

    2008-01-01

    The aim of this study is to evaluate the impact of the patient dose due to the kilovoltage cone beam computed tomography (kV-CBCT) in a prostate intensity-modulated radiation therapy (IMRT). The dose distributions for the five prostate IMRTs were calculated using the Pinnacle treatment planning system. To calculate the patient dose from CBCT, phase-space beams of a CBCT head based on the ELEKTA x-ray volume imaging system were generated using the Monte Carlo BEAMnr code for 100, 120, 130, and 140 kVp energies. An in-house graphical user interface called DOSCTP (DOSXYZnrc-based) developed using MATLAB was used to calculate the dose distributions due to a 360 degrees photon arc from the CBCT beam with the same patient CT image sets as used in Pinnacle. The two calculated dose distributions were added together by setting the CBCT doses equal to 1%, 1.5%, 2%, and 2.5% of the prescription dose of the prostate IMRT. The prostate plan and the summed dose distributions were then processed in the CERR platform to determine the dose-volume histograms (DVHs) of the regions of interest. Moreover, dose profiles along the x- and y-axes crossing the isocenter with and without addition of the CBCT dose were determined. It was found that the added doses due to CBCT are most significant at the femur heads. Higher doses were found at the bones for a relatively low energy CBCT beam such as 100 kVp. Apart from the bones, the CBCT dose was observed to be most concentrated on the anterior and posterior side of the patient anatomy. Analysis of the DVHs for the prostate and other critical tissues showed that they vary only slightly with the added CBCT dose at different beam energies. On the other hand, the changes of the DVHs for the femur heads due to the CBCT dose and beam energy were more significant than those of rectal and bladder wall. By analyzing the vertical and horizontal dose profiles crossing the femur heads and isocenter, with and without the CBCT dose equal to 2% of the

  15. Evaluation of the effect of patient dose from cone beam computed tomography on prostate IMRT using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Chow, James C. L.; Leung, Michael K. K.; Islam, Mohammad K.; Norrlinger, Bernhard D.; Jaffray, David A.

    2008-01-01

    The aim of this study is to evaluate the impact of the patient dose due to the kilovoltage cone beam computed tomography (kV-CBCT) in a prostate intensity-modulated radiation therapy (IMRT). The dose distributions for the five prostate IMRTs were calculated using the Pinnacle3 treatment planning system. To calculate the patient dose from CBCT, phase-space beams of a CBCT head based on the ELEKTA x-ray volume imaging system were generated using the Monte Carlo BEAMnrc code for 100, 120, 130, and 140 kVp energies. An in-house graphical user interface called DOSCTP (DOSXYZnrc-based) developed using MATLAB was used to calculate the dose distributions due to a 360 deg. photon arc from the CBCT beam with the same patient CT image sets as used in Pinnacle3. The two calculated dose distributions were added together by setting the CBCT doses equal to 1%, 1.5%, 2%, and 2.5% of the prescription dose of the prostate IMRT. The prostate plan and the summed dose distributions were then processed in the CERR platform to determine the dose-volume histograms (DVHs) of the regions of interest. Moreover, dose profiles along the x- and y-axes crossing the isocenter with and without addition of the CBCT dose were determined. It was found that the added doses due to CBCT are most significant at the femur heads. Higher doses were found at the bones for a relatively low energy CBCT beam such as 100 kVp. Apart from the bones, the CBCT dose was observed to be most concentrated on the anterior and posterior side of the patient anatomy. Analysis of the DVHs for the prostate and other critical tissues showed that they vary only slightly with the added CBCT dose at different beam energies. On the other hand, the changes of the DVHs for the femur heads due to the CBCT dose and beam energy were more significant than those of rectal and bladder wall. By analyzing the vertical and horizontal dose profiles crossing the femur heads and isocenter, with and without the CBCT dose equal to 2% of the

  16. Measurement of radioactive aerosol behavior during dismantling and reflection to the exposure dose evaluation - 16107

    International Nuclear Information System (INIS)

    Iguchi, Yukihiro; Kato, Masami

    2009-01-01

    Radioactive aerosol disperses slightly via contamination prevention systems such as control enclosures and filters when the nuclear installation is dismantled, and it might impact the environment. Therefore, when decommissioning is planned, it is necessary to assess the safety such as exposure dose evaluation to the public. For the radioactive aerosol, it is possible that the dispersion ratio is different according to the contamination condition, the dismantlement method of the material, nuclides (elements), etc. The radiation exposure evaluation for the decommissioning plan has been executed by operators in Japan based on a number of experiments (mostly cold tests) and overseas results. The decommissioning is now being carried out at the Tokai Power Station (GCR) and Fugen Decommissioning Engineering Center in Japan. In this study, the results data is acquired at the decommissioning sites, and the methodology and data for the exposure dose evaluation are verified and confirmed. These examination results will lead to the upgrading and improvement of the exposure evaluation methodology. In particular, the dismantlement work of connected piping of the heat exchanger (steam generator) was executed in the Tokai Power Station in 2008. In this study, we paid attention to the radionuclides of Co-60 and Cs-137 that adhered to piping, and the dispersion behavior of aerosol was measured and contamination prevention effect was assured. As a result, the data show that the cesium concentrates about four times higher than cobalt. Moreover, the effects of the prevention measures of contamination were confirmed and the behavior of the radioactive aerosol became clear and the effective findings about the dose evaluation of the dismantling were collected. (authors)

  17. Curie-type paramagnetic NMR relaxation in the aqueous solution of Ni(II).

    Science.gov (United States)

    Mareš, Jiří; Hanni, Matti; Lantto, Perttu; Lounila, Juhani; Vaara, Juha

    2014-04-21

    Ni(2+)(aq) has been used for many decades as a model system for paramagnetic nuclear magnetic resonance (pNMR) relaxation studies. More recently, its magnetic properties and also nuclear magnetic relaxation rates have been studied computationally. We have calculated electron paramagnetic resonance and NMR parameters using quantum-mechanical (QM) computation of molecular dynamics snapshots, obtained using a polarizable empirical force field. Statistical averages of hyperfine coupling, g- and zero-field splitting tensors, as well as the pNMR shielding terms, are compared to the available experimental and computational data. In accordance with our previous work, the isotropic hyperfine coupling as well as nuclear shielding values agree well with experimental measurements for the (17)O nuclei of water molecules in the first solvation shell of the nickel ion, whereas larger deviations are found for (1)H centers. We report, for the first time, the Curie-type contribution to the pNMR relaxation rate using QM calculations together with Redfield relaxation theory. The Curie relaxation mechanism is analogous to chemical shift anisotropy relaxation, well-known in diamagnetic NMR. Due to the predominance of other types of paramagnetic relaxation mechanisms for this system, it is possible to extract the Curie term only computationally. The Curie mechanism alone would result in around 16 and 20 s(-1) of relaxation rates (R1 and R2 respectively) for the (1)H nuclei of water molecules bonded to the Ni(2+) center, in a magnetic field of 11.7 T. The corresponding (17)O relaxation rates are around 33 and 38 s(-1). We also report the Curie contribution to the relaxation rate for molecules beyond the first solvation shell in a 1 M solution of Ni(2+) in water.

  18. Evaluation of dose conversion coefficients for external exposure using Taiwanese reference man and woman

    International Nuclear Information System (INIS)

    Chang, S.J.; Hung, S.Y.; Liu, Y.L.; Jiang, S.H.; Wu, J.

    2015-01-01

    Reference man has been widely used for external and internal dose evaluation of radiation protection. The parameters of the mathematical model of organs suggested by the International Commission of Radiological Protection (ICRP) are adopted from the average data of Caucasians. However, the organ masses of Asians are significantly different from the data of Caucasians, leading to potentially dosimetric errors. In this study, a total of 40 volunteers whose heights and weights corresponded to the statistical average of Taiwanese adults were recruited. Magnetic resonance imaging was performed, and T2-weighted images were acquired. The Taiwanese reference man and woman were constructed according to the measured organ masses. The dose conversion coefficients (DCFs) for anterior-posterior (AP), posterior-anterior (PA), right lateral (RLAT) and left lateral (LLAT) irradiation geometries were simulated. For the Taiwanese reference man, the average differences of the DCFs compared with the results of ICRP-74 were 7.6, 5.1 and 11.1 % for 0.1, 1 and 10 MeV photons irradiated in the AP direction. The maximum difference reached 51.7 % for the testes irradiated by 10 MeV photons. The size of the trunk, the volume and the geometric position of organs can cause a significant impact on the DCFs for external exposure of radiation. The constructed Taiwanese reference man and woman can be used in radiation protection to increase the accuracy of dose evaluation for the Taiwanese population. (authors)

  19. Dose evaluation model for radionuclides released from the spent nuclear fuel reprocessing plant in Rokkasho

    International Nuclear Information System (INIS)

    Hisamatsu, Shun'ichi; Iyogi, Takashi; Inaba, Jiro; Chiang, Jing-Hsien; Suwa, Hiroji; Koide, Mitsuo

    2007-01-01

    A dose evaluation model was developed for radionuclides released from the spent nuclear fuel reprocessing plant which is located in Rokkasho, Aomori Prefecture, and now undergoing test operation. The dose evaluation model suitable for medium- and long-term dose assessments for both prolonged and short-term releases of radionuclides to the atmosphere was developed on the PC. The ARAC-2, a particle tracing type dispersion model coupled with 3-D wind field calculation by a mass conservative model, was adopted as the atmospheric dispersion model. The terrestrial transfer model included movement in soil and groundwater as well as an agricultural and livestock farming system. The available site-specific social and environmental characteristics were incorporated in the model. Growing of the crops was also introduced and radionuclides absorbed were calculated from weight increase from the start of deposition to harvest, and transfer factors. Most of the computer code system of the models was completed by 2005, and this paper reports the results of the development. (author)

  20. The evaluation of radioprotection with low dose CT scanning in normal rabbits brain

    International Nuclear Information System (INIS)

    Zhang Shuqing; Gong Shenchu; Wang Tianle; Shen Yunxia; Cui Lei

    2008-01-01

    Objective: To determine wheather a lower radiation dose technique and various pitch could be used in CT of the rabbits' brain without jeopardizing the diagnostic accuracy of the images, and determine the evaluation of radioprotection with low dose CT scanning. Methods: Fifteen rabbits underwent CT using 200 mAs, 110 mAs or 70 mAs,and pitch 1.0 or 1.5. Anatomy details and the confidence level in reaching a diagnosis were evaluated by two radiologists in a double-blinded manner using a 4-point scoring system. The CTDI w of every group were compared. Results: For both reader there was no statistically significant difference between 6 group total score of 1-6 anatomical detail and each of 6 anatomical detail although score for each of 6 anatomical detail. The CTDI w of 70 mAs, in pitch 1.5 group decreased about 76.7%. Conclusion: Radiation dose reduction in brain CT is feasible in clinical use, and quality of images can be re- served. It plays an important role in radiation protection. (authors)

  1. Systems engineering approach for the reuse of metallic waste from NPP decommissioning and dose evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyung Woo; Kim, Chang Lak [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2017-03-15

    The oldest commercial reactor in South Korea, Kori-1 Nuclear Power Plant (NPP), will be shut down in 2017. Proper treatment for decommissioning wastes is one of the key factors to decommission a plant successfully. Particularly important is the recycling of clearance level or very low level radioactively contaminated metallic wastes, which contributes to waste minimization and the reduction of disposal volume. The aim of this study is to introduce a conceptual design of a recycle system and to evaluate the doses incurred through defined work flows. The various architecture diagrams were organized to define operational procedures and tasks. Potential exposure scenarios were selected in accordance with the recycle system, and the doses were evaluated with the RESRAD-RECYCLE computer code. By using this tool, the important scenarios and radionuclides as well as impacts of radionuclide characteristics and partitioning factors are analyzed. Moreover, dose analysis can be used to provide information on the necessary decontamination, radiation protection process, and allowable concentration limits for exposure scenarios.

  2. In pediatric leukemia, dose evaluation according to the type of compensators in total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Yeon [Dongnam Inst. of Radiological and Medical science, Busan (Korea, Republic of); Kim, Chang Soo; Kim, Jung Hoon [Dept. of Radiological Science, College of Health Science, Catholic University of Busan, Busan (Korea, Republic of)

    2015-04-15

    Total body irradiation (TBI) and chemotherapy are the pre-treatment method of a stem cell transplantations of the childhood leukemia. in this study, we evaluate the Quantitative human body dose prior to the treatment. The MCNPX simulation program evaluated by changing the material of the tissue compensators with imitation material of pediatric exposure in a virtual space. As a result, first, the average skin dose with the material of the tissue compensators of Plexiglass tissue compensators is 74.60 mGy/min, Al is 73.96 mGy/min, Cu is 72.26 mGy/min and Pb 67.90 mGy/min respectively. Second, regardless of the tissue compensators material that organ dose were thyroid, gentile, digestive system, brain, lungs, kidneys higher in order. Finally, the ideal distance between body compensator and the patient were 50 cm aparting each other. In conclusion, tissue compensators Al, Cu, Pb are able to replace of the currently used in Plexiglass materials.

  3. Using ferromagnetic nanoparticles with low Curie temperature for magnetic resonance imaging-guided thermoablation

    Directory of Open Access Journals (Sweden)

    Herynek V

    2016-08-01

    Full Text Available Vít Herynek,1 Karolína Turnovcová,2 Pavel Veverka,3 Tereza Dědourková,4,5 Pavel Žvátora,6 Pavla Jendelová,2 Andrea Gálisová,1 Lucie Kosinová,7 Klára Jiráková,2 Eva Syková2 1MR-Unit, Radiodiagnostic and Interventional Radiology Department, Institute for Clinical and Experimental Medicine, Prague, 2Department of Neuroscience, Institute of Experimental Medicine, 3Department of Magnetics and Superconductors, Institute of Physics, Czech Academy of Sciences, Prague, 4Department of Inorganic Technology, Faculty of Chemical Technology, University of Pardubice, 5SYNPO, akciová společnost, Pardubice, 6Department of Analytical Chemistry, Institute of Chemical Technology, 7Diabetes Center, Institute for Clinical and Experimental Medicine, Prague, Czech Republic Introduction: Magnetic nanoparticles (NPs represent a tool for use in magnetic resonance imaging (MRI-guided thermoablation of tumors using an external high-frequency (HF magnetic field. To avoid local overheating, perovskite NPs with a lower Curie temperature (Tc were proposed for use in thermotherapy. However, deposited power decreases when approaching the Curie temperature and consequently may not be sufficient for effective ablation. The goal of the study was to test this hypothesis. Methods: Perovskite NPs (Tc =66°C–74°C were characterized and tested both in vitro and in vivo. In vitro, the cells suspended with NPs were exposed to a HF magnetic field together with control samples. In vivo, a NP suspension was injected into a induced tumor in rats. Distribution was checked by MRI and the rats were exposed to a HF field together with control animals. Apoptosis in the tissue was evaluated. Results and discussion: In vitro, the high concentration of suspended NPs caused an increase of the temperature in the cell sample, leading to cell death. In vivo, MRI confirmed distribution of the NPs in the tumor. The temperature in the tumor with injected NPs did not increase

  4. Improvement of dose evaluation system for employees at severe accident in a nuclear power plant. Introduction of the dose rate conversion coefficient and addition of the access route edit function

    International Nuclear Information System (INIS)

    Sasaki, Yasuhiro; Minami, Noritoshi; Yoshida, Yoshitaka

    2006-01-01

    Institute of Nuclear Safety System, Inc. had developed the dose evaluation system to evaluate the radiation dose of employees at severe accident in a nuclear power plant. This system has features, which are (1) the dose rate of any evaluation point can be evaluated, (2) the dose rate at any time can be evaluated in consideration of the change in the radioactive source, (3) the dose rate map in the plant can be displayed (4) the dose along the access route when moving can be evaluated, and it is possible to use it for examination of the accident management guideline on the dose side etc.. To upgrade the dose evaluation function of this system, the improvements had been done which were introduction of the dose rate conversion coefficient and addition of the access route edit function. By introducing the dose rate conversion coefficient, the calculation time of the dose rate map in the plant was shortened at about 20 seconds, and a new function to evaluate time-dependent dose rate of any evaluation point was added. By adding the access route edit function, it became possible to re-calculate the dose easily at the route change. (author)

  5. Evaluation of inhaled and cutaneous doses of imidacloprid during stapling ornamental plants in tunnels or greenhouses.

    Science.gov (United States)

    Aprea, Cristina; Lunghini, Liana; Banchi, Bruno; Peruzzi, Antonio; Centi, Letizia; Coppi, Luana; Bogi, Mirella; Marianelli, Enrico; Fantacci, Mariella; Catalano, Pietro; Benvenuti, Alessandra; Miligi, Lucia; Sciarra, Gianfranco

    2009-09-01

    The aim of this research was to assess dermal and respiratory exposure of workers to imidacloprid during manual operations with ornamental plants previously treated in greenhouses or tunnels. A total of 10 female workers, 5 in greenhouses and 5 in tunnels, were monitored for 3 or 5 consecutive days. Actual skin contamination, excluding hands, was evaluated using nine filter paper pads placed directly on the skin. To evaluate the efficacy of protective clothing in reducing occupational exposure we also placed four pads on top of the outer clothing. Hand contamination was evaluated by washing with 95% ethanol. Respiratory exposure was evaluated by personal air sampling. Respiratory dose was calculated on the basis of a lung ventilation of 15 l/min. Absorbed doses were calculated assuming a skin penetration of 10% and a respiratory retention of 100%. Dislodgeable foliar residues (DFRs) were determined during the days of re-entry in order to determine the dermal transfer factor. From the dependence of dermal exposure of hands from DFRs, a mean transfer factor was estimated to be 36.4 cm(2)/h. Imidacloprid was determined by liquid chromatography with selective mass detection and electrospray interface in all matrices analysed. Respiratory dose was 4.1+/-4.0 (0.1-14.3)% and 3.0+/-2.0 (0.6-6.9)% (mean+/-SD (range)) of the total real dose during work in tunnels and greenhouses, respectively. The estimated absorbed doses, 0.29+/-0.45 microg/kg (0.06-2.25 microg/kg) body weight and 0.32+/-0.18 microg/kg (0.07-0.66 microg/kg) body weight (mean+/-SD (range)) in tunnels and in greenhouses, respectively, were less than the acceptable operator exposure level of 0.15 mg/kg body weight and than the acceptable daily intake of 0.05 mg/kg body weight. The hands and exposed skin of all workers were found to be contaminated, indicating that greater precautions, such as daily changing of gloves and clothing, are necessary to reduce skin exposure.

  6. Development of evaluation method of collective dose of general public considering the daily life activity and time use

    International Nuclear Information System (INIS)

    Nagaoka, Toshi; Saito, Kimiaki; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Moriuchi, Shigeru

    1994-11-01

    A code for evaluation of collective dose of general public to natural radiation has been developed, in which the variation of dose rate due to place of stay is taken into consideration. Only external exposure to natural radiation is subject to discussion in this report. Strict manner of dose evaluation requires the dose rate and the time period of stay for each place and for each person. It is possible to know (measure) them all, but not practicable. In this code, dose rate information was obtained from actually measured data by the authors and estimation based on the environmental conditions. Information on the time period of stay was obtained from a Survey Data on Time Use and Leisure Activities by Management and Coordination Agency, and from Statistical Yearbook of Tokyo with some realistic assumptions. By using them, collective dose was evaluated taking both the daily life style and dose rate varying place by place into consideration. In this report, the dose evaluation code and the results about doses for Tokyo citizens are mentioned. (author)

  7. Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

    International Nuclear Information System (INIS)

    Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

    2001-01-01

    The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

  8. [Evaluation of Dose Reduction of the Active Collimator in Multi Detector Row CT].

    Science.gov (United States)

    Ueno, Hiroyuki; Matsubara, Kosuke

    The purpose of this study was to evaluate the performance of active collimator by changing acquisition parameters and obtaining dose profiles in z-axis direction. Dose profiles along z-axis were obtained using XRQA2 Gafchromic film. As a result, the active collimator reduced overranging about 55% compared to that without the active collimator. In addition, by changing the combination of X-ray beam width (32 mm, 40 mm), pitch factor (1.4, 0.6), and the X-ray tube rotation time (0.5 s/rot, 1.0 s/rot), the overranging changed from 19.4 to 34.9 mm. Although the active collimator is effective for reducing overranging, it is necessary to adjust acquisition parameters by taking the properties of the active collimator for acquisition parameters, especially setting beam width, into consideration.

  9. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    International Nuclear Information System (INIS)

    Koike, Amanda C.R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C.H.

    2012-01-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  10. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    Science.gov (United States)

    Koike, Amanda C. R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C. H.

    2012-08-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  11. Technical Report: Evaluation of peripheral dose for flattening filter free photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Covington, E. L.; Moran, J. M.; Owrangi, A. M.; Prisciandaro, J. I., E-mail: joannp@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Ritter, T. A. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 and Department of Radiation Oncology, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan 48105 (United States)

    2016-08-15

    Purpose: To develop a comprehensive peripheral dose (PD) dataset for the two unflattened beams of nominal energy 6 and 10 MV for use in clinical care. Methods: Measurements were made in a 40 × 120 × 20 cm{sup 3} (width × length × depth) stack of solid water using an ionization chamber at varying depths (dmax, 5, and 10 cm), field sizes (3 × 3 to 30 × 30 cm{sup 2}), and distances from the field edge (5–40 cm). The effects of the multileaf collimator (MLC) and collimator rotation were also evaluated for a 10 × 10 cm{sup 2} field. Using the same phantom geometry, the accuracy of the analytic anisotropic algorithm (AAA) and Acuros dose calculation algorithm was assessed and compared to the measured values. Results: The PDs for both the 6 flattening filter free (FFF) and 10 FFF photon beams were found to decrease with increasing distance from the radiation field edge and the decreasing field size. The measured PD was observed to be higher for the 6 FFF than for the 10 FFF for all field sizes and depths. The impact of collimator rotation was not found to be clinically significant when used in conjunction with MLCs. AAA and Acuros algorithms both underestimated the PD with average errors of −13.6% and −7.8%, respectively, for all field sizes and depths at distances of 5 and 10 cm from the field edge, but the average error was found to increase to nearly −69% at greater distances. Conclusions: Given the known inaccuracies of peripheral dose calculations, this comprehensive dataset can be used to estimate the out-of-field dose to regions of interest such as organs at risk, electronic implantable devices, and a fetus. While the impact of collimator rotation was not found to significantly decrease PD when used in conjunction with MLCs, results are expected to be machine model and beam energy dependent. It is not recommended to use a treatment planning system to estimate PD due to the underestimation of the out-of-field dose and the inability to calculate dose

  12. Dose evaluation and establishment of reference levels in activity for nuclear medicine

    International Nuclear Information System (INIS)

    Ribeiro, Julio Cesar de Souza

    2017-01-01

    The International Commission on Radiation Protection (ICRP) has emphasized the importance of accurately determining the mean dose levels, or administered activity, received by the patients for each medical procedure that uses ionizing radiation. However, the number of bibliographic references addressing the need to know and optimize these levels is insufficient, or rather limited, which may lead to non-standardizes techniques, a lack of exposures control, and also the increase of associated radiological risks of these procedures. In this context, a software in Visual Basic® of Microsoft© language was developed whose function is to elaborate a method of obtaining the Reference Levels in Activity (RLA) for nuclear medicine patients by determining the third quartile of the examinations carried out. The program also allows obtaining absorbed dose values in critical organs based on patient specificities as age, sex and Body Mass Index (BMI) in order to evaluate the risk involved in each procedure. The main nuclear medicine diagnostic procedures were evaluated through the database of two public hospitals and a private clinic, obtaining the NRAs of each facility, where the software was validated by comparison with the traditionally accepted calculation methods. Due to the results obtained in each installation, in addition to NRA determination, gaps in treatment capacities and unjustified dose variations for the same procedure were identified, indicating the need for optimization. Thus, the developed program is able to provide the estimated values of effective and absorbed doses involved in each procedure, for each patient, providing reference values for nuclear medicine field, not available in the national scenario so far. (author)

  13. Study of consequences of a ionizing radiation exposure on the health of persons having stay at the Marie Curie school of Nogent-sur-Marne (Val-de-Marne); Etude des consequences d'une exposition aux rayonnements ionisants sur la sante des personnes ayant sejourne a l'ecole Marie Curie de Nogent-sur-Marne (Val-de-Marne)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    This study follows two other ones about the same subject. No one could bring elements to the question of the exposure impact on the population having stayed in the school. The old pupils and personnel have been exposed to radiation doses higher to the limit values of public exposure especially before 1987. The scientific knowledge suggest that the eventual sanitary consequences are in the area of low risks. The lack of exhaustiveness in the inquiry realisation and the lack of statistical power did not allow to measure the sanitary impact of ionizing radiation exposure among the former pupils of the Marie Curie school of Nogent sur Marne. (N.C.)

  14. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM)

    International Nuclear Information System (INIS)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier

    2013-01-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption

  15. Evaluation of energy responses for neutron dose-equivalent meters made in Japan

    International Nuclear Information System (INIS)

    Saegusa, J.; Yoshizawa, M.; Tanimura, Y.; Yoshida, M.; Yamano, T.; Nakaoka, H.

    2004-01-01

    Energy responses of three types of Japanese neutron dose-equivalent (DE) meters were evaluated by Monte Carlo simulations and measurements. The energy responses were evaluated for thermal neutrons, monoenergetic neutrons with energies up to 15.2 MeV, and also for neutrons from such radionuclide sources as 252 Cf and 241 Am-Be. The calculated results were corroborated with the measured ones. The angular dependence of the response and the DE response were also evaluated. As a result, reliable energy responses were obtained by careful simulations of the proportional counter, moderator and absorber of the DE meters. Furthermore, the relationship between pressure of counting gas and response of the DE meter was discussed. By using the obtained responses, relations between predicted readings of the DE meters and true DE values were studied for various workplace spectra

  16. Thermal structure of east and Southeast Asia. Comparison of results of Curie point depth analysis and heat flow data; Totonan Asia chiiki no ondo kozo. Curie ten shindo kaiseki kekka to chikaku netsu ryuryo tono hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, A; Okubo, Y; Matsubayashi, O [Geological Survey of Japan, Tsukuba (Japan)

    1997-10-22

    This paper describes the distribution of Curie point depth and its characteristics determined from the spectral analysis of magnetic anomaly data in East and Southeast Asia. It also describes relationships between the Curie point depth and the other geophysical information such as topography, heat flow data and tectonics. The Curie point depths are shallower than about 10 km at volcanic and geothermal areas, between 15 and 25 km at island arcs and back arc rifts, deeper than 20 km at continents, and deeper than 30 km at trenches. The Curie point depth (Dc) estimated from the heat flow data can be expressed by Dc=k{theta}c/q where k is thermal conductivity, q is heat flow, and {theta}c is Curie point. Based on the Curie point depths obtained from Curie point depth analysis in the cross section of northeast Japan and the averaged values of heat flow at individual points, they are distributed along a line of k{theta}c=1500[Wm{sup -1}]. Values of k{theta}c are small near the axis of Japan trench and large in the northeast Japan. It is considered that local anomalies can not be grasped from the spectral analysis. 21 refs., 3 figs.

  17. The Evaluation of Minimal Erythema Dose For Narrowband UVB in Patients Receiving Isotretinoin Treatment

    Directory of Open Access Journals (Sweden)

    Tuba Çetiner

    2012-09-01

    Full Text Available Background and Design: Although photosensitivity is considered as one of the side effects of retinoids, there is no consensus on this issue. In this study, we aimed to evaluate the minimal erythema dose (MED for narrowband ultraviolet B in patients receiving isotretinoin treatmentMaterial and Method: Phototesting was done by narrowband ultraviolet B irradiation on fifty patients for whom isotretinoin treatment was planned. MED values were calculated before treatment (MED1 and during treatment after reaching half of the target dose (kgx120 mg (MED2, and it was evaluated whether there was statistically significant difference between the two MED values. In addition, the patients were assessed according to their skin phototypes in this respect. Results: When the mean values of MED1 and MED2 were compared in all patients who were treated with 0.5-0.7 mg/kg/day isotretinoin, the mean of MED2 values was found to be lower than the mean of MED1 values. Clinically, sunburn erythema was seen in only 3 (6% patients during the treatment. When the patients were evaluated according to their skin phototypes, significant difference between the means of MED 1 and MED 2 values was not determined. Conclusion: Although isotretinoin treatment does not cause clinically sunburn erythema, it was associated with decrease in MED values.

  18. Three-dimensional portal image-based dose reconstruction in a virtual phantom for rapid evaluation of IMRT plans

    International Nuclear Information System (INIS)

    Ansbacher, W.

    2006-01-01

    A new method for rapid evaluation of intensity modulated radiation therapy (IMRT) plans has been developed, using portal images for reconstruction of the dose delivered to a virtual three-dimensional (3D) phantom. This technique can replace an array of less complete but more time-consuming measurements. A reference dose calculation is first created by transferring an IMRT plan to a cylindrical phantom, retaining the treatment gantry angles. The isocenter of the fields is placed on or near the phantom axis. This geometry preserves the relative locations of high and low dose regions and has the required symmetry for the dose reconstruction. An electronic portal image (EPI) is acquired for each field, representing the dose in the midplane of a virtual phantom. The image is convolved with a kernel to correct for the lack of scatter, replicating the effect of the cylindrical phantom surrounding the dose plane. This avoids the need to calculate fluence. Images are calibrated to a reference field that delivers a known dose to the isocenter of this phantom. The 3D dose matrix is reconstructed by attenuation and divergence corrections and summed to create a dose matrix (PI-dose) on the same grid spacing as the reference calculation. Comparison of the two distributions is performed with a gradient-weighted 3D dose difference based on dose and position tolerances. Because of its inherent simplicity, the technique is optimally suited for detecting clinically significant variances from a planned dose distribution, rather than for use in the validation of IMRT algorithms. An analysis of differences between PI-dose and calculation, δ PI , compared to differences between conventional quality assurance (QA) and calculation, δ CQ , was performed retrospectively for 20 clinical IMRT cases. PI-dose differences at the isocenter were in good agreement with ionization chamber differences (mean δ PI =-0.8%, standard deviation σ=1.5%, against δ CQ =0.3%, σ=1.0%, respectively). PI-dose

  19. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    International Nuclear Information System (INIS)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M

    2015-01-01

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations

  20. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M [Univ Florida, Jacksonville Beach, FL (United States)

    2015-06-15

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations.

  1. Radiobiological equivalent of low/high dose rate brachytherapy and evaluation of tumor and normal responses to the dose.

    Science.gov (United States)

    Manimaran, S

    2007-06-01

    The aim of this study was to compare the biological equivalent of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy in terms of the more recent linear quadratic (LQ) model, which leads to theoretical estimation of biological equivalence. One of the key features of the LQ model is that it allows a more systematic radiobiological comparison between different types of treatment because the main parameters alpha/beta and micro are tissue-specific. Such comparisons also allow assessment of the likely change in the therapeutic ratio when switching between LDR and HDR treatments. The main application of LQ methodology, which focuses on by increasing the availability of remote afterloading units, has been to design fractionated HDR treatments that can replace existing LDR techniques. In this study, with LDR treatments (39 Gy in 48 h) equivalent to 11 fractions of HDR irradiation at the experimental level, there are increasing reports of reproducible animal models that may be used to investigate the biological basis of brachytherapy and to help confirm theoretical predictions. This is a timely development owing to the nonavailability of sufficient retrospective patient data analysis. It appears that HDR brachytherapy is likely to be a viable alternative to LDR only if it is delivered without a prohibitively large number of fractions (e.g., fewer than 11). With increased scientific understanding and technological capability, the prospect of a dose equivalent to HDR brachytherapy will allow greater utilization of the concepts discussed in this article.

  2. An evaluation about the tools of doses calculation and future needs

    International Nuclear Information System (INIS)

    Thomassin, A.; Merle-Szeremeta, A.

    1999-01-01

    The purpose of this communication is to give an image of the situation in tools for doses calculation, and to look to the future. The Institute of Protection and Nuclear Safety, with its mission of dosimetric impact evaluation of any radioactive release or radioactive contamination is led to use numerous calculation tools. It appeared useful to take the stock of the situation on tools used at the I.P.S.N. but also out of the I.P.S.N.. (N.C.)

  3. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Alonso, Thessa C.; Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z.; Silva, Teogenes A. da

    2014-01-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  4. Exposure dose evaluation of worker at radioactive waste incineration facility on KAERI

    International Nuclear Information System (INIS)

    Park, Sang Kyu; Jeon, Jong Seon; Kim, Youn Hwa; Lee, Jae Min; Lee, Gi Won

    2011-01-01

    An incineration treatment of inflammable radioactive wastes leads to have a reduction effect of disposal cost and also to contribute an enhancement of safety at a disposal site by taking the advantage of stabilization of the wastes which is accomplished by converting organic materials into inorganic materials. As it was required for an incineration technology, KAERI (Korea Atomic Energy Research Institute) has developed a pilot incineration process and then constructed a demonstration incineration facility having based on the operating experiences of the pilot process. In this study, worker exposure doses were evaluated to confirm safety of workers before the demonstration incineration facility will commence a commercial. (author)

  5. Evaluation of absorbed radiation dose rate in a didactic X-ray equipment

    International Nuclear Information System (INIS)

    Costa, Phelipe Amaral Ferreira; Perini, Ana Paula; Neves, Lucio Pereira

    2016-01-01

    This work was performed in order to create a new didactic experiment in the X-ray apparatus of PHYWE, where the saturation current was obtained through a free air ionization chamber. The values of saturation currents were obtained in two ways. Initially, the anodic DDP was kept constant and the anodic current was varied. In the second way, the anodic current was kept constant while the anodic DDP was varied. Therefore, we were able to evaluate the dependence of the absolved dose rate in relation to the DDP and the tube current. (author)

  6. Evaluation of Radioactivity Concentration in Tilapia Nilotica and Radiation Dose to Egyptian Population

    Science.gov (United States)

    Amer, Hannan H.; El-Khawas, Enas H.

    2013-03-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate, and safe food. The study was carried out to evaluate the Uranium (238U) and thorium (232Th) concentration in the Bolti (Tilapia nilotica) fish collected from Nasser Lake by using two different types of detectors CR-39 SSNTDs and gamma spectroscopy. The annual intake of Bolti fish was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diet.

  7. Severe accident modeling and offsite dose consequence evaluations for nuclear power plant emergency planning

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.H.; Feng, T.S.; Huang, K.C. [National Tsing-Hua Univ., Hsinchu, Taiwan (China); Wang, J.R. [Inst. of Nuclear Energy Research, Longtan, Taiwan (China); Cheng, Y.H. [Industrial Tech. Res. Inst., Hsinchu, Taiwan (China); Shih, C., E-mail: ckshih@ess.nthu.edu.tw [National Tsing-Hua Univ., Hsinchu, Taiwan (China)

    2011-07-01

    We have investigated the roles of Firewater Addition System and Passive Flooder in ABWR severe accidents, such as LOCA and SBO. The results are apparent that Firewater System is vital in the highly unlikely situation where all AC are lost. Also in this paper, we present EPZDose, an effective and faster-than-real time code for offsite dose consequences predictions and evaluations. Illustrations with the release from our severe accident scenario show friendly and informative user's interface for supporting decision makings in nuclear emergency situations. (author)

  8. Evaluation of Radioactivity Concentration In Tilapia Nilotica and Radiation Dose to Egyptian Population

    International Nuclear Information System (INIS)

    Amer, H.H.; Khawas, E.H.; Nabil, G.M.

    2011-01-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate and safe food. The study was carried out to evaluate the uranium ( 238 U) and thorium ( 232 Th) concentrations in the Bolti fish (Tilapia nilotica) collected from Naser Lake by using two different types of detectors CR-39 SSNTD and gamma spectroscopy. The annual intake of Bolti fish was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diet

  9. Evaluation of the collective effective dose equivalent of atmospheric discharges in the Rhone valley

    International Nuclear Information System (INIS)

    Le Grand, J.; Despres, A.; Robeau, D.; Bouville, A.

    1982-01-01

    Two models were used to evaluate the integrated atmospheric concentrations: - TALD, a long-range atmospheric transport model which takes account of the actual trajectories of the discharged matter; - a Gaussian plume model which assumes straight-line trajectories defined by the wind at the point of emission. In order to bring out the differences due to the use of the two models the dose equivalents are presented as a function of wind direction at the point of emission and the contributions of the near zone and the further zone are compared. (author)

  10. Evaluation for committed effective dose due to dietary foods by the intake for Japanese adults

    International Nuclear Information System (INIS)

    Ota, Tomoko; Sanada, Tetsuya; Kashiwara, Yoko; Morimoto, Takao; Sato, Kaneaki

    2009-01-01

    Radioactivity levels in 137 foods commonly consumed daily in Japan were evaluated to determine the committed effective dose in the Japanese adults. The levels of radioactivity for 238 U, 232 Th, 226 Ra, 210 Pb, 210 Po, 90 Sr, 137 Cs and 239+240 Pu were ND-5.2 Bq/kg fresh weight, ND-0.18 Bq/kg fresh weight, ND-3.9 Bq/kg fresh weight, ND-45 Bq/kg fresh weight, ND-120 Bq/kg fresh weight, ND-9.9 Bq/kg fresh weight, ND-19 Bq/kg fresh weight and ND-0.010 Bq/kg fresh weight, respectively. The committed effective dose was estimated to be 0.80 mSv from the intake of the foods. The effective dose was greater than the world mean value for adults of 0.12 mSv by natural radioactive elements in the uranium and thorium series from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 because of the large contribution from 210 Po in seafood. (author)

  11. Evaluation of absorbed doses at the interface solid surfaces - tritiated water solutions

    International Nuclear Information System (INIS)

    Postolache, Cristian; Matei, Lidia

    2003-01-01

    Studies concerning the isotopic exchange H/D/T in the system elemental hydrogen -- water and in the presence of platinum metals on hydrophobic supports as catalysts were carried out at ICSI (Institute of Cryogenics and Isotope Separations) - Rm. Valcea, Romania. Due to the very low energy of β-radiation emitted by tritium, the direct measurements of dose absorbed by the isotopic exchange catalyst using classical methods is practically impossible. For this purpose an evaluation model was developed. The volume of tritiated water which can irradiate the catalyst was represented by a hemisphere with the radius equal to the maximal rate of β-radiation emitted by tritium. The catalyst surface is represented by a circle with a 0.2 μm radius and the same centre as the circle of the hemisphere secant plane. Flow rate of absorbed dose is calculated with the relation: d (1/100)(Φ·E m /m), where d = dose flow rate, in rad/s, Φ total radiation flux interacting with the catalyst surface, expressed in erg and m = catalyst weight, in grams. Total flux of available radiation, Φ, was determined as a function of three parameters: a) total flow of tritium β-radiation emitted in the hemisphere of tritiated water, dependent on the volume and radioactive concentration; b) emission coefficient in the direction of the catalyst surface; c) attenuation coefficient (due to self-absorption) of the tritium β-radiation in the tritiated water body. (authors)

  12. Computational fluid dynamics (CFD) assisted performance evaluation of the Twincer (TM) disposable high-dose dry powder inhaler

    NARCIS (Netherlands)

    de Boer, Anne H.; Hagedoorn, Paul; Woolhouse, Robert; Wynn, Ed

    Objectives To use computational fluid dynamics (CFD) for evaluating and understanding the performance of the high-dose disposable Twincer (TM) dry powder inhaler, as well as to learn the effect of design modifications on dose entrainment, powder dispersion and retention behaviour. Methods Comparison

  13. Evaluation of the appropriateness of imipenem/cilastatin prescription and dosing in a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Kabbara WK

    2015-03-01

    Full Text Available Wissam K Kabbara, George T Nawas, Wijdan H RamadanDepartment of Pharmacy Practice, School of Pharmacy, Lebanese American University, Byblos, Lebanon Background: Imipenem/cilastatin is an antibacterial agent of the carbapenem class of β-lactams that is known to have an extremely wide spectrum of activity against Gram-positive, Gram-negative, aerobic, anaerobic, and even multidrug-resistant strains. The objective of this study was to evaluate the appropriate use of imipenem/cilastatin in a local tertiary care hospital. The study assessed the indication both empirically and after the culture results were available, the dose and dose adjustment in renal failure, as well as the incidence of seizure in hospitalized patients receiving imipenem/cilastatin. Methods: This observational study was conducted in a tertiary care hospital over a 3-month period. The treatment of 100 patients with imipenem/cilastatin was evaluated both empirically and after culture results were available. Analysis of the appropriateness of imipenem/cilastatin indication, dose, and monitoring of seizure frequency was based on the package insert, updated published guidelines, and clinical judgment. Results: Patients from internal medicine and intensive care units comprised approximately 50% of the population in the study. The patients received imipenem/cilastatin mainly for urinary tract infections (27% or for sepsis of an unknown focus (22%. The use of imipenem/cilastatin empirically was appropriate in 97.2% (n=69/71 of the cases, and its use postculture in 86% of the cases. There were 29% of the patients who were not started on imipenem/cilastatin empirically. Four patients out of the 29 patients (13.8% who were not started on imipenem/cilastatin empirically inappropriately received imipenem/cilastatin post-culture results. Thirty-three patients (33% were not dosed appropriately, 30 of whom had renal impairment and creatinine clearance fluctuations. Only one patient developed a

  14. Individual dose burden evaluation in the residents of the vicinity of Semipalatinsk nuclear test site

    International Nuclear Information System (INIS)

    Lipikhina, A.V.; Valivach, M.N.; Kurakina, N.N.; Kosatov, V.G.; Federbush, E.G.; Bugembayeva, M.D.

    2003-01-01

    Full text: The evaluation of individual dose burden can be make by an estimation method based on the following parameters: - dose rate in the concrete settlement after concrete explosion; - time of stay of an individual under a cloud; - behavior of the individual in the subsequent time; - diet. The archive and published materials available today have these input parameters. At the same time, these materials have significant gaps, and are very contradictory. For example, the available published data on the explosion made on 24.09.1951 (the main dose forming explosion in Kainar) have the following data ranges: - gamma-radiation dose rate at 24 hours after explosion (71.3-304) mR/h; out-door time in an adult man - (6-16) h/day in the summer, (3-16) h/day in the winter; - consumption of milk by an adult man - (0.2-1) l/day. The time of stay of an individual under a cloud depends on the distance from epicenter to settlement and on wind velocity at the time of explosion. For explosion 24.09.1951 the following data have been published: distance from epicenter to settlement Kainar- (139-150) km; wind velocity-(15.0-26.4) km/h. Based on these ranges of data we can obtain, for example, the effective external gamma exposure dose estimates in an adult man (office worker), which range from 2.6 to 23.4 cSv. To verify these input data, we have determined: the distance from epicenter to settlement Kainar. This was made using electronic maps of Kazakhstan (SN ISBN 5-94552-085-x), and also the data of geographic coordinates database of the Russian Ministry of Emergency Situations. The distance is 142.1 km; the wind velocity based on the archive data of the Kazakh Regional State Weather Center, which was 15 km /h; - the out-door time in an adult man (office worker) was determined based on the results of an interview of Kainar residents. The out-door time in the adult was 6.859 h/day in the summer and 4.598 h/day in the winter. Based on these verified data the effective external gamma

  15. Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

    International Nuclear Information System (INIS)

    Yang, Lin; Liang, Changhong; Zhuang, Jian; Huang, Meiping; Liu, Hui

    2017-01-01

    Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose"4 and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose"4 levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose"4-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose"4 level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose"4 level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose"4 level 4 was optimal for both the full- and half-dose groups. Protocols with iDose"4 level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

  16. Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Liang, Changhong [Southern Medical University, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Zhuang, Jian [Guangdong Academy of Medical Sciences, Dept. of Cardiac Surgery, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Huang, Meiping [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Catheterization Lab, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Liu, Hui [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China)

    2017-01-15

    Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose{sup 4} and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose{sup 4} levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose{sup 4}-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose{sup 4} level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose{sup 4} level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose{sup 4} level 4 was optimal for both the full- and half-dose groups. Protocols with iDose{sup 4} level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

  17. Evaluation of radiation doses received by the staff in nuclear medicine department of Rick

    International Nuclear Information System (INIS)

    Ali, Naemat Abdalla Mohamed

    2001-01-01

    Environmental monitoring in nuclear medicine rooms at Radiation and Isotopes Center Khartoum RICK were carried out using survey meter and thermoluminescent dosimetry. Staff bodies and hands doses measurements are being conducted using thermoluminescent dosimetry. The purpose of the study is to evaluate the radiation received by the staff work in the nuclear medicine department at RICK. Survey meter (RDS-120) and TLD clips of LiF. (Mg.Ti) were used to measure the environment leading of the staff. The associated annual doses have been determined to the staff bodies and hands. It was found that the dose-equivalent rates from bodies and hands of the staff obtained through this work using TLD clips are: nuclear medicine technologist body reading 6.75 mSv per year, physicist body reading 7.89 mSv per year, chemist body reading 6.1 mSv per year, and nurse body reading 8.1 mSv per year. On the other hand the nuclear medicine technologist hands reading 24.19 mSv per year, physicist hands reading 19.15 mSv per year, chemist hands reading 14.616 mSv per year, and nurse hands reading 277.96 mSv per year. All the staff reading in this study agree with the national regulations and international recommendations. It is clear that the dose of nurse hands is the highest one, this is because when they inject the patient with the Tc-99 m they use to spend relatively long time. (Author)

  18. Dose evaluation by radon dispersion in the uranium mining tailings of Malargue

    International Nuclear Information System (INIS)

    Baron, J.; Bastianelli, B.; Ferrer, F.; Munoz, G.

    1996-01-01

    The objective of this work is the environmental impact evaluation of the uranium mining tailings actually sited in Malargue, due to atmospheric dispersion of radon gas and its inhalation by inhabitants of the vicinity Malargue factory complex is located at the south of Mendoza-Argentina. the complex was an industrial installation to treat uranium mineral, which started operation in 1954 and was operable until December 1986. As a by-product of this industrial process approximately 700 thousand tons of tailings were generated. They actually cover about 9 Ha in four piles with a ∼6 m height above the ground. their final disposal is at present under discussion, and in this frame the present work is performed. In the work a Gaussian-plume dispersion model was developed, using local meteorological data, with specific correlations to consider the different stability classes, according to the Pasquill-Gifford concept. The model is fed with the meteorological information provided by two towers mounted by the Atomic Energy Commission, that bring information each half hour. This information for 211 full days is available. The model considers the wind induced[dispersion, the corrections for emission period (discretized in half hour intervals), the stability class (automatically chosen as a function of day time and wind speed) and radioactive decay. The model calculates the inhalation dose with a non-equilibrium factor which depends on the time since release. Finally the model integrates the dose in time, and provides yearly doses in any coordinates point. Special attention was devoted to the fact that the source is extended, and several source discretization were performed until reliable results were obtained. the model allows for comparative calculations. As the work result the yearly doses were obtained, for four 'critical groups' of interest. They correspond to three nearby houses, and downtown Malargue. (authors). 6 refs., 3 tabs

  19. Evaluation of therapeutic effect of low dose naltrexone in experimentally-induced Crohn's disease in rats.

    Science.gov (United States)

    Tawfik, Dina Ibrahim; Osman, Afaf Sayed; Tolba, Hedayat Mahmoud; Khattab, Aida; Abdel-Salam, Lubna O; Kamel, Mahmoud M

    2016-10-01

    Crohn's disease is a relapsing inflammatory condition afflicting the digestive tract. Drugs used for treatment of Crohn's disease may be associated with serious side effects. Endogenous opioid peptides modulate inflammatory cytokine production. Opioid antagonists have been shown to play a role in healing and repair of tissues. This work was designed to detect the possible beneficial effects of opioid antagonist naltrexone in indomethacin-induced Crohn's disease in rats. Enteritis was induced in male albino rats by two subcutaneous injection of indomethacin in a dose of 7.5mg/kg 24h apart started on day one. Salfasalazine, naltrexone and their combination were administered orally from day one of induction of enteritis to day 10. Disease activity index, serum levels of C-reactive protein and tumor necrosis factor-α, macroscopic and microscopic pathological scores and in vitro motility studies were evaluated. Induction of enteritis resulted in significant increase of disease activity index, significant elevation of serum levels of C-reactive protein and tumor necrosis factor-α, significant deterioration of pathological scores and significant increase in the mean contractility response of the isolated ileal segments compared with normal untreated rats. Treatment with sulfasalazine, low dose of natrexone or their combination resulted in significant improvement of all measured parameters compared with enteritis group. The current finding could provide new interesting opportunity for developing new therapeutic approaches for treatment of Crohn's disease. Use of naltrexone, especially in small dose, has little side effects making it of interest for treatment of Crohn's disease. Also, it provides the possibility of reduced doses of other drugs if it is used as combined therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Evaluation of annual effective dose from indoor radon concentration in Eastern Province, Dammam, Saudi Arabia

    Science.gov (United States)

    Abuelhia, E.

    2017-11-01

    The aim of this study is to determine the indoor radon concentration and to evaluate the annual effective dose received by the inhabitants in Dammam, Al-Khobar, and compare it with new premises built at university of dammam. The research has been carried out by using active detection method; Electronic Radon Detector (RAD-7) a solid state α-detector with its special accessories. The indoor radon concentration measured varies from 10.2 Bqm-3 to 25.8 Bqm-3 with an average value of 18.8 Bqm-3 and 19.7 Bqm-3 to 23.5 Bqm-3 with an average value of 21.7 Bqm-3, in Dammam and Al-khobar dwellings, respectively. In university of dammam the radon concentration varies from 7.4 Bqm-3 to 15.8 Bqm-3 with an average value of 9.02 Bqm-3. The values of annual effective doses were found to be 0.47mSv/y, 0.55mSv/y, and 0.23mSv/y, in Dammam, Al-khobar and university new premises, respectively. The average radon concentration in the old dwellings was two times compared to that in the new premises and it was 25.4 Bqm-3 lower than the world average value of 40 Bqm-3 reported by the UNSCEAR. The annual effective doses in the old dwellings was found to be (0.55mSv/y) two times the doses received at the new premises, and below the world wide average of 1.15mSv/y reported by ICRP (2010). The indoor radon concentration in the study region is safe as far as health hazard is concerned.

  1. The Evaluation of the 0.07 and 3 mm Dose Equivalent with a Portable Beta Spectrometer

    Science.gov (United States)

    Hoshi, Katsuya; Yoshida, Tadayoshi; Tsujimura, Norio; Okada, Kazuhiko

    Beta spectra of various nuclide species were measured using a commercially available compact spectrometer. The shape of the spectra obtained via the spectrometer was almost similar to that of the theoretical spectra. The beta dose equivalent at any depth was obtained as a product of the measured pulse height spectra and the appropriate conversion coefficients of ICRP Publication 74. The dose rates evaluated from the spectra were comparable with the reference dose rates of standard beta calibration sources. In addition, we were able to determine the dose equivalents with a relative error of indication of 10% without the need for complicated correction.

  2. The evaluation of the 0.07 mm and 3 mm dose equivalent with a portable beta spectrometer

    International Nuclear Information System (INIS)

    Hoshi, Katsuya; Yoshida, Tadayoshi; Tsujimura, Norio; Okada, Kazuhiko

    2016-01-01

    Beta spectra of various nuclide species were measured using a commercially available compact spectrometer. The shape of the spectra obtained via the spectrometer was almost similar to that of the theoretical spectra. The beta dose equivalent at any depth was obtained as a product of the measured pulse height spectra and the appropriate conversion coefficients of ICRP Publication 74. The dose rates evaluated from the spectra were comparable with the reference dose rates of standard beta calibration sources. In addition, we were able to determine the dose equivalents with a relative error of indication of 10% without the need for complicated correction. (author)

  3. Evaluation of X ray radiation doses in pediatric examinations of cranial computerized tomography based on optimization studies

    International Nuclear Information System (INIS)

    Daros, Kellen Adriana Curci

    2005-01-01

    This paper identifies the technical conditions for CT examination which offers lowest absorbed dose and to attend the manufacturer recommendations as far the spatial resolution is concerned. The paper evaluates the absorbed dose during cranial CT in up to 6 years children satisfying the technical condition recommended by the manufacturer and routine clinical conditions. The paper also established a quantitative relationship among the absorbed dose and its distribution in the cranial regions of pediatric patients up to 6 years old in a way to estimate the doses subject to optimized conditions

  4. A generic high-dose rate {sup 192}Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo, E-mail: Facundo.Ballester@uv.es [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Carlsson Tedgren, Åsa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden and Department of Medical Physics, Karolinska University Hospital, Stockholm SE-171 76 (Sweden); Granero, Domingo [Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia E-46014 (Spain); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Institute of Technology, Melbourne, Victoria 3000 (Australia); Mourtada, Firas [Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, Delaware 19713 (United States); Fonseca, Gabriel Paiva [Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Zourari, Kyveli; Papagiannis, Panagiotis [Medical Physics Laboratory, Medical School, University of Athens, 75 MikrasAsias, Athens 115 27 (Greece); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Siebert, Frank-André [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel 24105 (Germany); Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); and others

    2015-06-15

    Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) {sup 192}Ir source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR {sup 192}Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic {sup 192}Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra{sup ®} Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS{sup TM}]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201){sup 3} voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR {sup 192}Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by

  5. High pressure and doping effects on the Curie temperature in chromium telluride

    International Nuclear Information System (INIS)

    Grazhdankina, N.P.; Bersenev, Yu.S.

    1976-01-01

    Results of an experimental investigation of the effect of hydrostatic pressure (up to 12 kbars) on the Curie temperature Tsub(c) of solid CrTsub(1-x)Xsub(x) solutions (X=Se, Sb) are presented for x concentration values up to 0.5. The baric coefficients γ=Tsub(c)sup(-1)(dTsub(c)/dP) for all alloys investigated are negative. However the γ(x) dependence is determined by the X alloy component and correspondingly by the nature of the compression which may be either isotropic (X=Se) or anisotropic (X=Sb). Possible mechanisms of exchange spin coupling in the alloys investigated are discussed on the basis of the data obtained. It is concluded that two types of exchange interactions coexist in chromium telluride: indirect exchange of localized electrons via the anion and interaction between collectivized electrons in the narrow 3d band energy determines the Curie temperature

  6. Theory of group extension, Shubnikov-Curie principle and phase transformations

    International Nuclear Information System (INIS)

    Koptsik, V.A.; Talis, A.L.

    1983-01-01

    It is shown, that the generalized Curie principle (GCP) is the principle of nondecreasing abstract symmetry under structural transformations in (quasi) isolated physical systems. Asymmetry of such systems at any structural level is compensated by their symmetrization at another one, transformation of the old and appearance of qualitatively new symmetries. A corresponding situation is preserved also at the description level (mathematical simulation) of physical systems. Structural levels of substance arrangement and forms of connection between them, reflected by the Shubnikov-Curie (SCP) and GCP are inexhaustible. With the discovery of new structural levels and new forms of relations between them can be discovered and new forms of SCP, which can not be exhausted in the given work

  7. Frederic Joliot-Curie the history of a civic-minded scientist

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The year 2000 marks the hundredth anniversary of the birth of Frederic Joliot-Curie, who can be safely termed as one of the most prominent figures of the twentieth century. The scientist and his wife Irene discovered artificial radioactivity at the Radium Institute; in 1935, they received the Nobel Chemistry Prize for their discovery. At the College de France four years later, Frederic Joliot-Curie uncovered the conditions required for a chain reaction in uranium. He gave meaning to the word civic-minded citizen. His many deeds were a statement that a scientist should offer more than his research and its possible applications to society; that he should not shrink from committing to political and social struggles. That is why this exceptional man is a model of a committed scientist. (author)

  8. Comparison of dose evaluation index by pencil beam convolution and anisotropic analytical algorithm in stereotactic radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Tachibana, Masayuki; Noguchi, Yoshitaka; Fukunaga, Jyunichi; Hirano, Naomi; Yoshidome, Satoshi; Hirose, Takaaki

    2009-01-01

    We previously studied dose distributions of stereotactic radiotherapy (SRT) for lung cancer. Our aim is to compare in combination pencil beam convolution with the inhomogeneity correction algorithm of Batho power low [PBC (BPL)] to the anisotropic analytical algorithm (AAA) by using the dose evaluation indexes. There were significant differences in D95, planning target volume (PTV) mean dose, homogeneity index, and conformity index, V10, and V5. The dose distributions inside the PTV calculated by PBC (BPL) were more uniform than those of AAA. There were no significant differences in V20 and mean dose of total lung. There was no large difference for the whole lung. However, the surrounding high-dose region of PTV became smaller in AAA. The difference in dose evaluation indexes extended between PBC (BPL) and AAA that as many as low CT value of lung. When the dose calculation algorithm is changed, it is necessary to consider difference dose distributions compared with those of established practice. (author)

  9. Patient dose evaluations from medical X-ray exposure in Italy: an analysis of next data

    International Nuclear Information System (INIS)

    Marchetti, A.; Paganini, F.M.; Susanna, A.

    1980-01-01

    NEXT (Nationwide Evaluation of X-ray Trends) is a program for the evaluation of patient exposure in X-ray diagnostic tests. The program is aimed at reducing patient exposure by pin-pointing poor radiological techniques and improving them. CNEN (Comitato Nazionale per l'Energia Nucleare) and ISS (Istituto Superiore di Sanita) have been developing such a program in Italy since 1976. Up to now two regional administrations applied the method and regional operators collected the needed data in all the medical institutions in their areas. The results show a wide spread of values for all the parameters studied in the 12 X-ray projections selected. Gonad dose and skin entrance exposure were found to be spread over a range up to about two orders of magnitude. (H.K.)

  10. Ambient dose evaluation at mammographic installations through the spectrum of barrier transmitted beams

    International Nuclear Information System (INIS)

    Silva, Marcia C.; Costa, Paulo R.; Herdade, Silvio B.; Furquim, Tania A.C.; Terini, Ricardo A.

    2001-01-01

    National regulations (Ministerial Rule 453, 1998) state that ambient dose equivalent (ADE) must be the operational quantity to verify the conformance with dose constraint levels in area surveys. It's difficulty to evaluate ADE's through conventional radiometric measurements performed in the neighbor areas of examination room because of the low energy levels utilized by mammographic equipment. Therefore, it is necessary to know the radiation spectrum incident in the area. Spectra of X-rays scattered by a breast tissue equivalent phantom have been measured in a controlled area adjacent to a mammography room, using a portable high resolution spectrometer, and taking into account typical workload distributions. The raw spectra was corrected for changes of detector efficiency with photon energy and converted to fluence units (photons/keV.m 2 ). After, air kerma values (in mGy/m As) was calculated for each corrected spectrum. The ADE's (in mSv/year) was obtained by two ways: firstly using the constant conversion factor 1.14 Sv/Gy, adopted by the Ministerial Rule 453 and used in ionization chambers; secondly, through the conversion factor (Sv/Gy) versus energy curve. Results show clearly that the ADE values are overestimated when adopting the usual methodology and that the proposed method furnishes more realistic data for the evaluation of protective shielding. (author)

  11. Evaluation of the directional dose equivalent H,(0.07) for ring dosemeters

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Tovar M, V.M.

    2006-01-01

    The personnel dosimetry laboratory (LDP) of the Metrology department received an user's of radiation beta application that incidentally had irradiated 14 couples of ring dosemeters for extremities of the type TLD-100 given by the LDP. This sample of 14 couples of rings tentatively it was irradiated in the months of July-August of the year 2004, and he requested in an expedite way the evaluation of the received dose equivalent. The LSCD builds two calibration curves in terms of the directional dose equivalent H'(0.07) using two sources patterns of 90 Sr- 90 Y for beta radiation: one of 74 MBq and another of 1850 MBq with traceability to the PTB. The first curve in the interval of 0 to 5 mSv, the second in the range of 5 to 50 mSv, taking into account effects by positioned of the rings in the phantom. Both calibration curves were validated by adjustment lack, symmetry of residuals and normality of the same ones. It is evaluated and analyzing the H'(0.007) for these 14 couples of rings using the Tukey test of media of a single road. It was found that the H , its could be classified in 4 groups, and that the probability that its has irradiated in a random way it was smaller to the level at α = 0.05. (Author)

  12. Evaluation of a flat panel digital radiographic system for low-dose portable imaging of neonates

    International Nuclear Information System (INIS)

    Samei, Ehsan; Hill, Jeanne G.; Frey, G. Donald; Southgate, W. Michael; Mah, Eugene; Delong, David

    2003-01-01

    The purpose of this study was to evaluate the clinical utility of an investigational flat-panel digital radiography system for low-dose portable neonatal imaging. Thirty image-pairs from neonatal intensive care unit patients were acquired with a commercial Computed Radiography system (Agfa, ADC 70), and with the investigational system (Varian, Paxscan 2520) at one-quarter of the exposure. The images were evaluated for conspicuity and localization of the endings of ancillary catheters and tubes in two observer performance experiments with three pediatric radiologists and three neonatologists serving as observers. The results indicated no statistically significant difference in diagnostic quality between the images from the investigational system and from CR. Given the investigational system's superior resolution and noise characteristics, observer results suggest that the high detective quantum efficiency of flat-panel digital radiography systems can be utilized to decrease the radiation dose/exposure to neonatal patients, although post-processing of the images remains to be optimized. The rapid availability of flat-panel images in portable imaging was found to be an added advantage for timely clinical decision-making

  13. Dose-ranging evaluation of intravitreal siRNA PF-04523655 for diabetic macular edema (the DEGAS study)

    DEFF Research Database (Denmark)

    Nguyen, Quan Dong; Schachar, Ronald A; Nduaka, Chudy I

    2012-01-01

    To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation.......To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation....

  14. Calculating the Curie temperature reliably in diluted III-V ferromagnetic semiconductors

    Czech Academy of Sciences Publication Activity Database

    Bouzerar, G.; Ziman, T.; Kudrnovský, Josef

    2005-01-01

    Roč. 69, č. 5 (2005), s. 812-818 ISSN 0295-5075 R&D Projects: GA AV ČR(CZ) IAA1010203; GA ČR(CZ) GA202/04/0583 Institutional research plan: CEZ:AV0Z10100520 Keywords : local RPA * Curie temperaure * ab-initio * Heisenberg model * magnetic percolation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.237, year: 2005

  15. Curie-therapy of prostate cancer assisted by three-dimensional echography and robot

    International Nuclear Information System (INIS)

    Bolla, M.; Giraud, J.Y.; Descotes, J.L.; Long, J.A.; Hungr, N.; Baumann, M.; Troccaz, J.

    2011-01-01

    The author present and report the first assessments of the Prosper system which is based on the use of a robot coupled to methods of automatic tracking of prostate by three-dimensional ultrasonic imagery. This system aims at solving some difficulties met by curie-therapy. System accuracy has been assessed on a deformable anatomic phantom: a needle can be positioned with accuracy smaller that 2 mm, despite deformations and movements of the prostate embedded in the phantom. Short communication

  16. Curie temperatures of fcc and bcc Nickel and Permalloy: Supercell and Green's function methods

    Czech Academy of Sciences Publication Activity Database

    Yu, P.; Jin, X.F.; Kudrnovský, Josef; Wang, D. S.; Bruno, P.

    2008-01-01

    Roč. 77, č. 5 (2008), 054431/1-054431/8 ISSN 1098-0121 R&D Projects: GA MŠk OC 150; GA AV ČR IAA100100616 Institutional research plan: CEZ:AV0Z10100520 Keywords : fcc - and bcc-Ni * Permalloy * magnetic moments * Curie temperatures Subject RIV: BE - Theoretical Physics Impact factor: 3.322, year: 2008

  17. Experimental determination of the Curie temperature for Ga(Mn)As

    Czech Academy of Sciences Publication Activity Database

    Vašek, Petr; Svoboda, Pavel; Novák, Vít; Výborný, Zdeněk; Jurka, Vlastimil; Smrčka, Ludvík

    2011-01-01

    Roč. 24, 1-2 (2011), s. 805-808 ISSN 1557-1939 R&D Projects: GA MŠk MEB020928; GA AV ČR KAN400100652 Institutional research plan: CEZ:AV0Z10100521 Keywords : Ga(Mn)As * Hall effect * magnetoresistance * Curie temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.650, year: 2011

  18. Building of a facility for the handling of kilo-curie amounts of gamma emitters

    International Nuclear Information System (INIS)

    Germond, Ph.

    1960-01-01

    A hot cell designed to handle up to 1000 curies of cobalt-60 has been built in a preexisting shielded room, in order to make optimum use of available space. Heavy containers can be rolled in or out of the cell. Handling performed with two manipulators designed and made by French manufacturers, one of them is pneumatically operated and the other one is mechanical. The general shape of the facility is that of an L. (author) [fr

  19. Evaluation of homogeneity and dose conformity in IMRT planning in prostate radiotherapy; Avaliacao da homogeneidade e conformidade de dose em planejamentos de IMRT de prostata em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Juliane S.; Leidens, Matheus; Estacio, Daniela R., E-mail: juliane.lopes@pucrs.br [Hospital Sao Lucas (PUC-RS), Porto Alegre, RS (Brazil). Servico de Radioterapia; Razera, Ricardo A.Z.; Streck, Elaine E.; Silva, Ana M.M. da [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Fisica

    2015-12-15

    The goal of this study was to evaluate the dose distribution homogeneity and conformity of radiation therapy plans of prostate cancer using IMRT. Data from 34 treatment plans of Hospital Sao Lucas of PUCRS, where those plans were executed, were retrospectively analyzed. All of them were done with 6MV X-rays from a linear accelerator CLINAC IX, and the prescription doses varied between 60 and 74 Gy. Analyses showing the homogeneity and conformity indices for the dose distribution of those plans were made. During these analyses, some comparisons with the traditional radiation therapy planning technic, the 3D-CRT, were discussed. The results showed that there is no correlation between the prescribed dose and the homogeneity and conformity indices, indicating that IMRT works very well even for higher doses. Furthermore, a comparison between the results obtained and the recommendations of ICRU 83 was carried out. It has also been observed that the indices were really close to the ideal values. 82.4% of the cases showed a difference below 5% of the ideal value for the index of conformity, and 88.2% showed a difference below 10% for the homogeneity index. Concluding, it is possible to confirm the quality of the analyzed radiation therapy plans of prostate cancer using IMRT. (author)

  20. Evaluation of patient doses from upper gastrointestinal tract examinations based on the dosimetry in an anthropomorphic phantom

    International Nuclear Information System (INIS)

    Hirofuji, Yoshiaki; Aoyama, Takahiko; Koyama, Shuji; Kawaura, Chiyo

    2005-01-01

    The objective of this study was to evaluate organ dose and effective dose to patients from examinations of the upper gastrointestinal (GI) tract. Absorbed doses of various tissues and organs were measured using novel photodiode dosimeters installed in an anthropomorphic phantom representing a standard Japanese adult body. The organ dose and the effective dose were assessed from the absorbed doses according to the definitions seen in the publications of the International Commission on Radiological Protection. Dose measurements were performed for each projection of the upper GI tract examination in seven procedures at four hospitals and in a mobile coach, and organ and effective doses were assessed for each procedure. Organ doses obtained in the observation areas such as the stomach, esophagus and colon were in the order of several to more than 60 mGy, though they decreased to less than 1 mGy for tissues and organs distant from the observation areas. Organ doses and effective doses differed largely according to tube voltage, filtration and tube current or mAs value of the x-ray generator used, and by examination protocol, number of images, fluoroscopy time, and imaging units such as screen/film, computed radiography, digital radiography and flat panel detector. The number of images and the fluoroscopy time were 7 and 1.5 min for the examination in the mobile coach, and 18-22 and 2-6 min in the hospitals. Evaluated effective dose for the examination in the mobile coach was 2.9 mSv, and that in the hospitals ranged from 4.0-13.4 mSv at a ratio of more than three. (author)