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Sample records for absorbed fraction internal irradiation

  1. An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters

    Directory of Open Access Journals (Sweden)

    Ernesto Amato

    2014-03-01

    Full Text Available We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'generalized radius', calculated as 3V/S, where V is the ellipsoid volume and S its surface. Radiation-specific parametric functions were obtained in order to calculate the absorbed fraction of a given radiation in a generic ellipsoidal volume. The dose from a generic radionuclide can be calculated through a process of summation and integration over the whole radionuclide emission spectrum, profitably implemented in an electronic spreadsheet. We compared the results of our analytical calculation approach with those obtained from the OLINDA/EXM computer software, finding a good agreement in a wide range of sphere radii, for the high-energy pure beta emitter 90Y, the commonly employed beta-gamma emitter 131I, and the pure alpha emitter 213Po. The generality of our approach makes it useful an easy to implement in clinical dosimetry calculations as well as in radiation safety estimations when doses from internal radionuclide uptake are to be taken into account.

  2. An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters

    OpenAIRE

    Amato, Ernesto; Italiano, Antonio; Baldari, Sergio

    2014-01-01

    We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'general...

  3. Calculation of absorbed dose of anchorage-dependent cells from internal beta-rays irradiation

    International Nuclear Information System (INIS)

    Chen Jianwei; Huang Gang; Li Shijun

    2001-01-01

    Objective: To elicit the formula of internal dosimetry in anchorage-dependent cells by beta-emitting radionuclides from uniformly distributed volume sources. Methods: By means of the definition of absorbed dose and the MIRD (Medical International Radiation Dose) scheme the formula of internal dosimetry was reasonably deduced. Firstly, studying the systems of suspension culture cells. Then, taking account of the speciality of the systems of the anchorage-dependent cells and the directions of irradiation, the absorbed dose of anchorage -dependent cells was calculated by the accumulated radioactivity, beta-ray energy, and the volume of the cultured systems. Results: The formula of internal dosimetry of suspension culture cells and anchorage-dependent cells were achieved. At the same time, the formula of internal dosimetry of suspension culture cells was compared with that of MIRD and was confirmed accurate. Conclusion: The formula of internal dosimetry is concise, reliable and accurate

  4. Specific absorbed fractions of energy at various ages from internal photon sources: 7, Adult male

    International Nuclear Information System (INIS)

    Cristy, M.; Eckerman, K.F.

    1987-04-01

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for an adult male (70-kg Reference Man). These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  5. Specific absorbed fractions of energy at various ages from internal photon sources: 1, Methods

    International Nuclear Information System (INIS)

    Cristy, M.; Eckerman, K.F.

    1987-04-01

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. This volume outlines various methods used to compute the PHI-values and describes how the ''best'' estimates recommended by us are chosen. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods that Spiers and co-workers developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with the methods at photon energies below 200 keV. 41 refs., 25 figs., 23 tabs

  6. Specific absorbed fractions of energy at various ages from internal photon sources: 3, Five-year-old

    International Nuclear Information System (INIS)

    Cristy, M.; Eckerman, K.F.

    1987-04-01

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a five-year-old or 19-kg person. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  7. Computational modeling of the mathematical phantoms of the Brazilian woman to internal dosimetry calculations and for comparison of the absorbed fractions with specific reference women

    International Nuclear Information System (INIS)

    Ximenes, Edmir; Guimaraes, Maria Ines C. C.

    2008-01-01

    The theme of this work is the study of the concept of mathematical dummy - also called phantoms - used in internal dosimetry and radiation protection, from the perspective of computer simulations. In this work he developed the mathematical phantom of the Brazilian woman, to be used as the basis of calculations of Specific Absorbed Fractions (AEDs) in the body's organs and skeleton by virtue of goals with regarding the diagnosis or therapy in nuclear medicine. The phantom now developed is similar, in form, to Snyder phantom making it more realistic for the anthropomorphic conditions of Brazilian women. For so we used the Monte Carlo method of formalism, through computer modeling. As a contribution to the objectives of this study, it was developed and implemented the computer system cFAE - consultation Fraction Specific Absorbed, which makes it versatile for the user's query researcher

  8. Gamma dose rates to body organs from immersion in a semi-infinite radioactive cloud; an alternate approach using absorbed fraction data for internal radionuclides

    International Nuclear Information System (INIS)

    Gillespie, F.C.

    1982-01-01

    This note shows that reasonable estimates of absorbed γ-dose rates for specific organs arising from whole body immersion in semi-infinite radioactive clouds may be obtained very simply from well known data on absorbed fractions for mono-energetic γ-sources uniformly distributed in the whole body. (author)

  9. Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetry and ends of comparison of the fractions absorbed specific with the woman reference

    International Nuclear Information System (INIS)

    Ximenes, Edmir

    2006-01-01

    Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97 R computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF - consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several 'look-up' facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them. (author)

  10. Preparation of super absorbent by irradiation polymerization

    International Nuclear Information System (INIS)

    Hua Fengjun; Tan Chunhong; Qian Mengping

    1995-01-01

    A kind of absorbent is prepared by gamma-rays irradiated by reversed-phase suspension polymerization. Drying particles have 1400 (g/g) absorbency in de-ionic water. Effects of reactive conditions, e.g.: dose-rate, dose, monomer concentration, degree of monomer neutralization and crosslinking agents on absorbency in de-ionic water are discussed. The cause of absorbing de-ionic water by polymer is related to its network structure and ionic equilibrium in particle. Accordingly, a suit reactive condition is chosen for preparation of hydro gel spheres

  11. Pregnant woman mode for absorbed fraction calculations

    International Nuclear Information System (INIS)

    Cloutier, R.J.; Snyder, W.S.; Watson, E.E.

    1977-01-01

    The most radiation-sensitive segment of our population is the developing fetus. Until recently, methods available for calculating the dose to the fetus were inadequate because a model for the pregnant woman was not available. Instead, the Snyder and Fisher model of Reference Man, which includes a uterus, was frequently used to calculate absorbed fractions when the source was in various organs of the body and the nongravid uterus was the target. These values would be representative of the dose to the embryo during the early stages of pregnancy. Unfortunately, Reference Man is considerable larger than Reference Woman. The authors recently reported on the design of a Reference Woman phantom that has dimensions quite similar to the ICRP Reference Woman. This phantom was suitable for calculating the dose to the embryo during early stages of pregnancy (0 to 3 mo.), but was not suitable for the later stages of pregnancy because of the changing shape of the mother and the displacement of several abdominal organs brought about by the growth of the uterus and fetus. The models of Reference Woman that were subsequently developed for each month of pregnancy are described. The models take into account the growth of the uterus and fetus and the repositioning of the various abdominal organs. These models have been used to calculate absorbed fractions for the fetus as a target and the gastrointestinal tract as a source of radiation for twelve photon energies ranging from 10 keV to 4 MeV

  12. Absorbed fractions for alpha particles in ellipsoidal volumes

    International Nuclear Information System (INIS)

    Amato, Ernesto; Baldari, Sergio; Italiano, Antonio

    2013-01-01

    Internal dosimetry of alpha particles is gaining attention due to the increasing applications in cancer treatment and also for the assessment of environmental contamination from radionuclides. We developed a Monte Carlo simulation in GEANT4 in order to calculate the absorbed fractions for monoenergetic alpha particles in the energy interval between 0.1 and 10 MeV, uniformly distributed in ellipsoids made of soft tissue. For each volume, we simulated a spherical shape, three oblate and three prolate ellipsoids, and one scalene shape. For each energy and for every geometrical configuration, an analytical relationship between the absorbed fraction and a ‘generalized radius’ was found; and the dependence of the fit parameters on the alpha energy is discussed and fitted by parametric functions. With the proposed formulation, the absorbed fraction for alpha particles in the energy range explored can be calculated for volumes and for ellipsoidal shapes of practical interest. This method can be applied to the evaluation of absorbed fraction from alpha-emitting radionuclides. The contribution to the deposited energy coming from electron and photon emissions can be accounted for exploiting the specific formulations previously introduced. As an example of application, the dosimetry of 213 Bi and its decay chain in ellipsoids is reported. (paper)

  13. Absorbed dose modeled for a liquid circulating around a Co-60 irradiator

    International Nuclear Information System (INIS)

    Mangussi, J.

    2013-01-01

    A model for the distribution of the absorbed dose in a volume of liquid circulating into an active tank containing a Co-60 irradiator is presented. The absorbed dose, the stir process and the liquid recirculation into the active tank are modeled. The absorbed dose for different fractions of the volume is calculated. The necessary irradiation times for the achievement of the required absorbed dose are evaluated. (author)

  14. Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

    International Nuclear Information System (INIS)

    Wang Wen; Hu Liqin; Cheng Mengyun; Long Pengcheng

    2015-01-01

    The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females. (authors)

  15. Development of UV absorbing PET through Electron Irradiation

    International Nuclear Information System (INIS)

    Kim, Jung Woo; Lee, Na Eun; Lim, Hyung San; Park, Yang Jeong; Cho, Sung Oh

    2017-01-01

    Experiment to increase UV absorbance through electron beam irradiation on PET was performed. Moreover, surface hardness and roughness of each sample were observed to find the key factor increasing UV absorbance. PET sheets were irradiated with an electron beam at various fluences. The irradiated samples, as well as pristine sample, were subjected to UV-visible spectral study(UV-Vis), pencil hardness test, and scanning electron microscopy(SEM) experiment. In this study, PET samples irradiated at several conditions were analyzed through various measurements. UV absorbance-another meaning of transmittance in this study- of irradiated PET sample increased compared with pristine sample as fluence was increased in UV-Visible spectroscopy experiment.

  16. Self Absorbed Fraction for Electrons and Beta Particles in Small Spherical Volumes

    International Nuclear Information System (INIS)

    Grosev, D.

    2003-01-01

    Absorbed fraction and target organ mass are important parameters of internal dosimetry calculations that define the geometry of the system. Standard MIRD (Medical Internal Radiation Dosimetry) formalism assumes that the absorbed fraction for non-penetrating radiations (e.g., electrons, beta particles) is 1. This may not be correct in cases where dimensions of organs/tissues are comparable with the ranges of electrons/beta particles. Such is the case for example in radiodine ablation of thyroid remnant tissue. In this work the self-absorbed fraction (source and target volumes are the same) for monoenergetic electrons and beta particles is calculated for small spherical volumes of various sizes and unit density. Absorbed fraction can be expressed as an integral of the product of two quantities: (a) Scaled beta dose point kernel (mean absorbed dose rate per activity of the point source in infinite homogenous medium), F β ; (b) special geometrical reduction factor (GRF). F β is calculated using EGS4 Monte Carlo (MC) code for transport of electrons and photons. MC source code calculates the deposition of energy inside concentric spherical shells around the isotropic point source of electrons/beta particles in infinite medium (water). Shell thickness was δr=0.02·X 90 , where X 90 represents the radius of the sphere inside which 90% of the source energy is absorbed. Number of concentric spherical shells was 100, 10000 electron histories were started in each program run, and 10 runs were repeated for statistical reason. Numerical integration of the product of F β , calculated by MC program, and GRF for sphere was done using Simpson method. Absorbed fractions were calculated for spheres with mass from 0.01-20 g (r = 0.13 - 1.68 cm). Results are given for monoenergetic electrons with kinetic energy T=0.2, 0.4, 1.0 MeV, and for three beta emitters 1 31I , 3 2P , 9 0Y . For quantitative dosimetric protocols in radioiodine ablation therapy, results for 1 31I are of

  17. Recycling Pig Slurry Solid Fraction Compost as a Sound Absorber

    Directory of Open Access Journals (Sweden)

    Niccolò Pampuro

    2018-01-01

    Full Text Available The aim of this investigation was to determine the physical and acoustical properties of compacts made from composted pig slurry solid fraction (SF in order to assess the potential to recycle this agricultural waste as a sound absorber. The compacts were obtained by compression. The physical parameters investigated were bulk density, durability, and particle size distribution. The acoustical features of the compacts were studied with an impedance tube device in order to verify the acoustic absorption coefficient. Two composts were prepared: pig SF compost without a bulking agent (SSFC and pig SF compost with wood chips as a bulking agent (WCC. The study’s results indicated that compost particles dimension played a key role in the physical and acoustical properties of the compacts: the smaller the particles, the higher the physical and acoustical properties of the compacts. The densification process increased the bulk density of the investigated composts up to 690 kg m−3 for SSFC and 660 kg m−3 for WWC, with, respectively, medium (77.9% and low (66.5% durability. The addition of woody bulking agent significantly reduced the absorption coefficient: the best results, in terms of potential use as a sound absorber, were observed for compacts made from composted pig slurry solid fraction without the addition of wood chips.

  18. A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions

    International Nuclear Information System (INIS)

    Watson, E.E.; Stabin, M.G.

    1987-01-01

    Existing models which allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs.; 2 figs

  19. A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions

    International Nuclear Information System (INIS)

    Watson, E.E.; Stabin, M.G.

    1986-01-01

    Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six, and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs., 2 figs

  20. Absorbed Dose Distributions in Irradiated Plastic Tubing and Wire Insulation

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1979-01-01

    Plastic tubing and wire insulation were simulated by radiochromic dye dosimeter films having electron absorbing properties similar to the materials of interest (polyethylene and PVC). A 400-keV electron accelerator was used to irradiate from 1, 2, 3 and 4 sides simulating possible industrial...

  1. Fractionated irradiation and haematopoiesis. Pt. 3

    International Nuclear Information System (INIS)

    Ninkov, V.; Karanovic, D.; Savovski, K.

    1982-01-01

    The effect of total single fractionated irradiation with short time interval on heamatopoietic regeneration of the bone marrow and spleen was investigated. Also, the importance of first dose, when dose of 600 R was divided in two unequal fractions with time interval of 300 s was studied. The investigation was performed on 25 day old rats. The dose of 600 R (X-rays) was divided on: 500 + 100, 400 + 200, 300 + 300, 200 + 400 or 100 + 500 R with time interval of 150, 300 or 600 s. Ten days after irradiation the changes in blood, bone marrow and spleen were observed. After unequal fractionated dose with interval of 600 s slight effect was found. The results after intervals of 600 s and 300 s were significant, when the total dose was divided in two equal doses. The first dose has no promoting role in haematopoietic regeneration when total dose was unequally fractionated. (orig.) [de

  2. Fractionated irradiation and haematopiesis. Pt. 2

    International Nuclear Information System (INIS)

    Ninkov, V.; Piletic, O.; Karanovic, D.; Belgrade Univ.

    1980-01-01

    Haemoregeneration after the irradiation with 600 R was studied using two different fractions given before and after the transplantation of bone-marrow cells. The dose of 600 R was divided in two uneven fractions: 500 + 100 R, 400 + 200 R and 300 + 300 R. During the free interval between the two doses (5 min) transplantation of bone-marrow cells was performed. Recolonization of bone-marrow and spleen was analysed on the 10th day after treatment. For analysis, samples of blood, bone-marrow and spleen were used. Maximal effect was found in the experimental group of animals irradiated with 500 R before and with 100 R after marrow-cell transplantation. Minimal haematopoietic response was in the group irradiated with 300 R before and after transplantation. This points at the importance of the primary dose for acceptance of the transplants and their activation. (orig.) [de

  3. Specification of absorbed dose for reporting a therapeutic irradiation

    International Nuclear Information System (INIS)

    Wambersie, A.; Chassagne, D.

    1981-01-01

    The problem of dose specification in external beam therapy with photons and electrons has been dealt with in ICRU Report 29 (1978). This problem arises from the fact that the absorbed dose distribution is usually not uniform in the target volume and that for the purpose of treatment reporting a nominal absorbed dose - which will be called target absorbed dose - has to be selected. When comparing the clinical results obtained between radiotherapy centres, the differences in the reported target absorbed doses which can be introduced by differences in the methods of dose specification often are much larger than the differences related to the dosimetric procedures themselves. This shows the importance of the problem. In this paper, some definitions of terms and concepts currently used in radiotherapy are first recalled: tumour volume, target volume, treatment volume, etc. These definitions have been proposed in ICRU Report 29 for photon and electron beams; they can be extended to any kind of irradiation. For external beam therapy with photons and electrons, the target absorbed dose is defined as the absorbed dose at selected point(s) (specification point(s)) having a meaningful relation to the target volume and/or the irradiation beams. Examples are discussed for typical cases. As far as interstitial and intracavitary therapy is concerned, the problem is more complex and no recommendations have so far been made by the ICRU Commission. A major difficulty arises from the sharp dose gradient as a function of the distance to the sources. The particular case of the treatment of cervix carcinoma is considered and some possible methods of specification are discussed: (1) the indication of the sources (in adequate units) and the duration of the application, (2) the absorbed doses at selected reference points (bladder, rectum, bony structures) and (3) the description of the tissue volume (height, width, thickness) encompassed by a given isodose surface (60Gy). (author)

  4. Estimate of absorbed dose received by individuals irradiated with neutrons

    International Nuclear Information System (INIS)

    Fonseca, E.S. da; Mauricio, C.L.P.

    1995-01-01

    An innovating methodology is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the methodology here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μGy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author). 5 refs., 1 fig., 4 tabs

  5. Study the Characterization of Spectral Absorbance on Irradiated Milk Protein

    Science.gov (United States)

    Fohely, F.; Suardi, N.

    2018-04-01

    The milk has been adopted as a structural nature food for a long era since it is containing most of the growth factors, protective agents, and enzymes needed for the body. a few attempts have been conducted to treat the dairy products especially raw milk by the means of ionizing radiation. as its production has been an expanding industry for many years due to the high demands from the consumers worldwide, there is still some doubt about preserving these products by irradiation. In this work, a preliminary effort to describe the influences of ionizing radiation on raw milk’s protein will be devoted to measuring the spectral absorbance of the total protein (after subjected to varied radiation doses) by UV-VIS-NIR spectroscopy analysis. The absorbance spectrum then analyzed based on absorbance spectra of organic compounds. A comparison is made between the effects of different radiation doses to estimate the influence in milk’s structure.

  6. Effects of internal and external scatter on the build-up characteristics of Monte Carlo calculated absorbed dose for electron irradiation

    International Nuclear Information System (INIS)

    Lin, H.; Wu, DS.; Wu, AD.

    2005-01-01

    The effects of internal and external scatter on surface, build-up and depth dose characteristics simulated by Monte Carlo code EGSnrc for varying field size and SSD for a 10 MeV monoenergetic electron beam with and without an accelerator model are extensively studied in this paper. In particular, sub-millimetre surface PDD was investigated. The percentage depth doses affected significantly by the external scatter show a larger build-up dose. A forward shifted Dmax depth and a sharper fall-off region compared to PDDs with only internal scatter considered. The surface dose with both internal and external scatter shows a marked decrease at 110 cm SSD, and then slight further changes with the increasing SSD since few external scattered particles from accelerator model can reach the phantom for large SSDs. The sharp PDD increase for the 5 cm x 5 cm field compared to other fields seen when only internal scatter is considered is significantly less when external scatter is also present. The effect of external scatter on surface PDD is more pronounced for large fields than small fields (5 cm x 5 cm field)

  7. Hypericin photocytotoxicyty followed after fractionated light irradiation

    International Nuclear Information System (INIS)

    Sackova, V.; Kulikova, L.; Mikes, J.; Kleban, J.; Fedorocko, P.

    2006-01-01

    The present study demonstrates the in vitro effect of hypericin-mediated photodynamic therapy with fractionated light delivery. Cells were photosensitized with unequal light fractions separated by dark intervals (1 h, 6 h). The changes in survival, apoptosis and cell cycle were compared on HT-29 cells irradiated with a single light dose (12 J/cm 2 ) to the fractionated light delivery (1+11 J/cm 2 ) 24 h and 48 h after photodynamic treatment. It was found that a fractionated light regime with a longer dark period resulted in a decrease of hypericin photo-cytotoxicity. Cell survival was higher after light sensitization with a 6 h dark interval. DNA fragmentation occurred after a single light dose application, but in contrast no apoptotic DNA formation was detected with a 6 h dark pause. After fractionation the percentage of cells in G 1 phase of the cell cycle was increased, while the proportion of cells in the G 2 phase decreased as compared to a single light dose application i. e. both percentage of cells in G 1 and G 2 phase of cell cycle were near control levels. We presume that the longer dark interval after the irradiation of cells by first light dose makes them to resistant to the effect of the second illumination. These findings confirm that the light application scheme together with other photodynamic protocol components is crucial for the photo-cytotoxicity of hypericin. (authors)

  8. Changes of arterial blood pressure, heart rate, internal body temperature, and blood acido-basic balance in the unanaesthetized rabbit following whole-body gamma irradiation at a mean absorbed dose of 250 rads

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, R.; Court, L.

    1973-09-01

    The general effects of whole-body gamma -irradiation at a mean absorbed dose of 250 rads were studied simultaneously in the unanaesthetized rabbit for 48 hours. They occurred early, with the following characteristics: arterial blood pressure decreased steadily as early as the 2nd hour and reached its minimum value on the 5th hour with a decrease of about 14%; it remained low during the following two days. Heart rate increased during the first hour, was the highest by the end of the second hour, and resumed normal value on the 24th hour. Internal body temperature increased during the 1st hour and was maximum by the end of the 2nd hour, with a mean increase of 1.2 deg C; hyperthermia steadily decreased between the 4th and the 6th hours and had completely disappeared by the 24th hour. Respiratory alkalosis is shown in the acido-basic balance by a raise of pH, a decrease of PCO/sub 2/ and arterial blood bicarbonates. These various changes seem to indicate a double origin, both central and peripheral. (FR)

  9. Acute skin reaction after fractionated irradiation

    International Nuclear Information System (INIS)

    Kozubek, S.

    1983-01-01

    Experimental data on acute mouse and pig skin reaction after fractionated γ or X irradiation have been analysed in terms of a new cell tissue kinetic model. The exponential-quadratic and generalized Huggett formulae have been used for cell lethality description. Fairly better results could be demonstrated with generalized Huggett formula. The speed of repopulation has been determined for fractionated regimes as well as for some irregular schedules. The repopulation is slower in the case of fractionated treatment. On considering the normal cell loss factor in the tissue, minimum cell cycle time has been calculated. Its value differs for various strains (Tsub(d)=28.8 hours for SAS/TO mice and Tsub(d) < or approximately 17 hours for WHT/Ht mice) and does not differ for plucked skin. The repopulation has been shown to follow exponential dependence after some latent period. Other factors influencing the effectiveness of radiation treatment (the length of the latent period or the changes of the survival curve during fractionated irradiation) have been considered, too

  10. Patient absorbed radiation doses estimation related to irradiation anatomy

    International Nuclear Information System (INIS)

    Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes

    2014-01-01

    Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector

  11. International document on food irradiation

    International Nuclear Information System (INIS)

    1990-06-01

    This international document highlights the major issues related to the acceptance of irradiated food by consumers, governmental and intergovernmental activities, the control of the process, and trade. The conference recognized that: Food irradiation has the potential to reduce the incidence of foodborne diseases. It can reduce post-harvest food losses and make available a larger quantity and a wider variety of foodstuffs for consumers. Regulatory control by competent authorities is a necessary prerequisite for introduction of the process. International trade in irradiated foods would be facilitated by harmonization of national procedures based on internationally recognized standards for the control of food irradiation. Acceptance of irradiated food by the consumer is a vital factor in the successful commercialization of the irradiation process, and information dissemination can contribute to this acceptance

  12. Neutron Absorbing Ability Variation in Neutron Absorbing Material Caused by the Neutron Irradiation in Spent Fuel Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Hee Dong; Han, Seul Gi; Lee, Sang Dong; Kim, Ki Hong; Ryu, Eag Hyang; Park, Hwa Gyu [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

    2014-10-15

    In spent fuel storage facility like high density spent fuel storage racks and dry storage casks, spent fuels are stored with neutron absorbing materials installed as a part of those facilities, and they are used for absorbing neutrons emitted from spent fuels. Usually structural material with neutron absorbing material of racks and casks are located around spent fuels, so it is irradiated by neutrons for long time. Neutron absorbing ability could be changed by the variation of nuclide composition in neutron absorbing material caused by the irradiation of neutrons. So, neutron absorbing materials are continuously faced with spent fuels with boric acid solution or inert gas environment. Major nuclides in neutron absorbing material are Al{sup 27}, C{sup 12}, B{sup 11}, B{sup 10} and they are changed to numerous other ones as radioactive decay or neutron absorption reaction. The B{sup 10} content in neutron absorbing material dominates the neutron absorbing ability, so, the variation of nuclide composition including the decrease of B{sup 10} content is the critical factor on neutron absorbing ability. In this study, neutron flux in spent fuel, the activation of neutron absorbing material and the variation of nuclide composition are calculated. And, the minimum neutron flux causing the decrease of B{sup 10} content is calculated in spent fuel storage facility. Finally, the variation of neutron multiplication factor is identified according to the one of B{sup 10} content in neutron absorbing material. The minimum neutron flux to impact the neutron absorbing ability is 10{sup 10} order, however, usual neutron flux from spent fuel is 10{sup 8} order. Therefore, even though neutron absorbing material is irradiated for over 40 years, B{sup 10} content is little decreased, so, initial neutron absorbing ability could be kept continuously.

  13. International Developments of Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940`s: discovery of principles of food irradiation; 1950`s: initiation of research in advanced countries; 1960`s: research and development were intensified in some advanced and developing countries; 1970`s: proof of wholesomeness of irradiated foods; 1980`s: establishment of national regulations; 1990`s: commercialization and international trade. (Author)

  14. International Developments of Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P [Head, Food Preservation Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1998-12-31

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940`s: discovery of principles of food irradiation; 1950`s: initiation of research in advanced countries; 1960`s: research and development were intensified in some advanced and developing countries; 1970`s: proof of wholesomeness of irradiated foods; 1980`s: establishment of national regulations; 1990`s: commercialization and international trade. (Author)

  15. International Developments of Food Irradiation

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1997-01-01

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940's: discovery of principles of food irradiation; 1950's: initiation of research in advanced countries; 1960's: research and development were intensified in some advanced and developing countries; 1970's: proof of wholesomeness of irradiated foods; 1980's: establishment of national regulations; 1990's: commercialization and international trade. (Author)

  16. Food irradiation receives international acceptance

    Energy Technology Data Exchange (ETDEWEB)

    Beddoes, J M [Atomic Energy of Canada Ltd., Ottawa, Ontario. Commercial Products

    1982-04-01

    Irradiation has advantages as a method of preserving food, especially in the Third World. The author tabulates some examples of actual use of food irradiation with dates and tonnages, and tells the story of the gradual acceptance of food irradiation by the World Health Organization, other international bodies, and the U.S. Food and Drug Administration (USFDA). At present, the joint IAEA/FAO/WHO standard permits an energy level of up to 5 MeV for gamma rays, well above the 1.3 MeV energy level of /sup 60/Co. The USFDA permits irradiation of any food up to 10 krad, and minor constituents of a diet may be irradiated up to 5 Mrad. The final hurdle to be cleared, that of economic acceptance, depends on convincing the food processing industry that the process is technically and economically efficient.

  17. International status of food irradiation

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1982-09-01

    Recent international moves that are likely to result in an increasing acceptance of irradiated foods are reviewed. Particular attention is given to the activities of the FAO, WHO, Codex Alimentarius and to attitudes in the United States and the Asian-Pacific region. In 1979, the Codex Alimentarius Commission adopted a Recommended General Standard for Irradiated Food. A resume is given of a revised version of the standard that is presently under consideration. However, remaining barriers to trade in irradiated food are briefly discussed, such as legal and regulatory problems, labelling, public acceptance and economic viability

  18. Response functions for computing absorbed dose to skeletal tissues from photon irradiation-an update

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Perry B; Bahadori, Amir A [Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Eckerman, Keith F [Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Lee, Choonsik [Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892 (United States); Bolch, Wesley E, E-mail: wbolch@ufl.edu [Nuclear and Radiological/Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2011-04-21

    A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues-active and total shallow marrow-within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R{sup 2} = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

  19. International status of food irradiation

    International Nuclear Information System (INIS)

    Diehl, J.F.

    1983-01-01

    Radiation processing of foods has been studied for over 30 years. To a considerable extent this research was carried out in the framework of various international projects. After optimistic beginnings in the 1950s and long delays, caused by uncertainty about the health safety of foods so treated, food irradiation has now reached the stage of practical application in several countries. In order to prepare the way for world-wide accceptance of the new process, the Codex Alimentarius Commission has accepted an 'International General Standard for Irradiated Foods' and an 'International Code of Practice for the Operation of Irradiation Facilities Used for the Treatment of Foods'. Psychological barriers to a process associated with the word 'radiation' are still formidable; it appears, however, that acceptance by authorities, food industry and consumers continues to grow

  20. Absorbed fractions in a voxel-based phantom calculated with the MCNP-4B code.

    Science.gov (United States)

    Yoriyaz, H; dos Santos, A; Stabin, M G; Cabezas, R

    2000-07-01

    A new approach for calculating internal dose estimates was developed through the use of a more realistic computational model of the human body. The present technique shows the capability to build a patient-specific phantom with tomography data (a voxel-based phantom) for the simulation of radiation transport and energy deposition using Monte Carlo methods such as in the MCNP-4B code. MCNP-4B absorbed fractions for photons in the mathematical phantom of Snyder et al. agreed well with reference values. Results obtained through radiation transport simulation in the voxel-based phantom, in general, agreed well with reference values. Considerable discrepancies, however, were found in some cases due to two major causes: differences in the organ masses between the phantoms and the occurrence of organ overlap in the voxel-based phantom, which is not considered in the mathematical phantom.

  1. Fractionated proton beam irradiation of pituitary adenomas

    International Nuclear Information System (INIS)

    Ronson, Brian B.; Schulte, Reinhard W.; Han, Khanh P.; Loredo, Lilia N.; Slater, James M.; Slater, Jerry D.

    2006-01-01

    Purpose: Various radiation techniques and modalities have been used to treat pituitary adenomas. This report details our experience with proton treatment of these tumors. Methods and Materials: Forty-seven patients with pituitary adenomas treated with protons, who had at least 6 months of follow-up, were included in this analysis. Forty-two patients underwent a prior surgical resection; 5 were treated with primary radiation. Approximately half the tumors were functional. The median dose was 54 cobalt-gray equivalent. Results: Tumor stabilization occurred in all 41 patients available for follow-up imaging; 10 patients had no residual tumor, and 3 had greater than 50% reduction in tumor size. Seventeen patients with functional adenomas had normalized or decreased hormone levels; progression occurred in 3 patients. Six patients have died; 2 deaths were attributed to functional progression. Complications included temporal lobe necrosis in 1 patient, new significant visual deficits in 3 patients, and incident hypopituitarism in 11 patients. Conclusion: Fractionated conformal proton-beam irradiation achieved effective radiologic, endocrinological, and symptomatic control of pituitary adenomas. Significant morbidity was uncommon, with the exception of postradiation hypopituitarism, which we attribute in part to concomitant risk factors for hypopituitarism present in our patient population

  2. Radioprotective effect of exogenic hypoxia in fractionated irradiation

    International Nuclear Information System (INIS)

    Kazymbetov, P.; Yarmonenko, S.P.; Vajnson, A.A.

    1988-01-01

    During the experiments with mice it is established, that exogenic hypoxia protective effect (8%O 2 ), evaluated according to survival rate, decreases at the change from single to fractionated irradiation. Dose change factor (DCF) is equal to 1.55 and 1.22-1.31, respectively. Skin protection using exogenic hypoxia at the local fractionated irradiation is expressed more, than at the fractionated one. DCF is equal to 1.56 and 1.28, respectively. Exogenic hypoxia protection effect in the tumor is expressed rather weakly. DCF at single and fractionated irradiation constitutes 1.03 and 1.07-1.13, respectively. Due to skin preferential protection the therapeutic gain factor at irradiation under the exogenic hypoxia conditions constitutes 1.24 and 1.38-1.46, respectively, at single and fractionated irradiation

  3. Food irradiation receives international acceptance

    International Nuclear Information System (INIS)

    Beddoes, J.M.

    1982-01-01

    Irradition has advantages as a method of preserving food, especially in the Third World. The author tabulates some examples of actual use of food irradiation with dates and tonnages, and tells the story of the gradual acceptance of food irradiation by the World Health Organization, other international bodies, and the U.S. Food and Drug Administration (USFDA). At present, the joint IAEA/FAO/WHO standard permits an energy level of up to 5 MeV for gamma rays, well above the 1.3 MeV energy level of 60 Co. The USFDA permits irradiation of any food up to 10 krad, and minor constituents of a diet may be irradiated up to 5 Mrad. The final hurdle to be cleared, that of economic acceptance, depends on convincing the food processing industry that the process is technically and economically efficient

  4. Internal friction in irradiated textolite

    International Nuclear Information System (INIS)

    Zajkin, Yu.A.; Kozhamkulov, B.A.; Koztaeva, U.P.

    1996-01-01

    Structural relaxation in irradiated textolite of ST and ST-EhTF trade marks presenting pressed material got by method of impregnation of fibreglass by phenole and epoxytriphenole binders relatively. Measuring of temperature dependences of internal friction (TDIF) is carried out in torsional pendulum at oscillation frequency 0.6-1.0 Hz before and after irradiation by stopped gamma-quanta with energy 3 MeV on electron accelerator EhLU-4. α and β peaks, related with segments motion in base and side chains of macromolecular have being observed on TDIF of all textolite. Growth of peaks height after irradiation evident about increase of segments mobility in base chain and about de-freezing of segments in side chains and it could be considered as qualitative measure of radiation destruction rate. Comparison of temperature dependences of internal friction indicates on higher radiation stability of textolite of ST-EhTF trade mark

  5. Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN/MG), Belo Horizonte, MG (Brazil)], e-mail: gas@cdtn.br, e-mail: pls@cdtn.br, e-mail: fcp@cdtn.br, e-mail: lcmb@cdtn.br, e-mail: pabloag@cdtn.br

    2009-07-01

    The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

  6. Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

    International Nuclear Information System (INIS)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade

    2009-01-01

    The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

  7. Internal irradiation for cystic craniopharyngioma

    International Nuclear Information System (INIS)

    Kobayashi, Tatsuya; Kageyama, Naoki

    1979-01-01

    Internal irradiation with P-32 chromic phosphate and Au-198 colloid was used to treat cystic craniopharyngioma. A newly developed dosimetric formula, by which the radiation dose can be calculated simultaneously at the cyst wall and at a point far from the radioactive source and the untoward effect of irradiation on surrounding brain tissue can be eliminated, especially in cases in which the wall is thin and can be penetrated by beta emission, was used. Radioactive phosphate or gold was injected into eight craniopharyngioma cysts throught the Ommaya reservoir and a tube inserted at the first craniotomy. All cysts were effectively treated for 3 to 33 months, to eliminate fluid retention or collapse. A collapsed cyst was removed at the second craniotomy and irradiation was histologically shown to be effective. Oculomotor palsy, a side effect of irradiation, occurred 10 days after the injection of 5 mc of P-32 chromic phosphate only in a case of small cysts (5.0 ml) in the supra- and intracellular regions. The thickness of the cyst wall was less than 0.5 mm and the oculomotor nerves were thought to adhere to the wall. Not only the amount of wall dose but also the thickness of the wall and localization of the cyst are important factors in internal irradiation. Sufficient and safer doses which kill tumor cells in the wall and have no side effects, are 9,000 to 30,000 rad. Internal irradiation can be used to treat large cysts of more than 10 ml which are supposedly difficult to remove radically and or multiple cysts. It is effective not only for cystic craniopharyngioma but also for intracrania cystic tumors other than craniopharyngioma, if dosimetry is accurate. (J.P.N.)

  8. Internal irradiation for cystic craniopharyngioma

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kageyama, N.; Ohara, K.

    1981-01-01

    The authors report the results of internal irradiation with labeled chromic phosphate (32P) and gold-198 (198Au) colloid in eight cases of cystic craniopharyngiomas. They used a newly developed dosimetric formula, by which the radiation dose at the cyst wall and at any point far from the radioactive source can be calculated. Ten courses of irradiation in eight patients were carried out by injection of either 32P or 198Au colloid into the cyst through an Ommaya drainage system that had been placed at craniotomy. Follow-up studies ranging from 13 to 156 months revealed that all cysts were effectively treated, with elimination of fluid or collapse of the cyst. This was confirmed by Conray cystography and/or computerized tomography. Not only the dose delivered to the wall but also the thickness of the cyst wall and the location of the cyst are important factors in planning internal irradiation. A safe and adequate dose to the cyst wall could range between 9000 to 30,000 rads for craniopharyngioma. This treatment is suitable for large cysts that are thought to be difficult to remove radically, recurrent cysts resistant to previous treatment, or multiple cysts. Internal irradiation may also be applicable in other cystic intracranial tumors if dosimetry is calculated accurately

  9. An international intercomparison of absorbed dose measurements for radiation therapy

    International Nuclear Information System (INIS)

    Taiman Kadni; Noriah Mod Ali

    2002-01-01

    Dose intercomparison on an international basis has become an important component of quality assurance measurement i.e. to check the performance of absorbed dose measurements in radiation therapy. The absorbed dose to water measurements for radiation therapy at the SSDL, MINT have been regularly compared through international intercomparison programmes organised by the IAEA Dosimetry Laboratory, Seibersdorf, Austria such as IAEA/WHO TLD postal dose quality audits and the Intercomparison of therapy level ionisation chamber calibration factors in terms of air kerma and absorbed dose to water calibration factors. The results of these intercomparison in terms of percentage deviations for Cobalt 60 gamma radiation and megavoltage x-ray from medical linear accelerators participated by the SSDL-MINT during the year 1985-2001 are within the acceptance limit. (Author)

  10. A mathematical model for the kidney and estimative of the specific absorbed fractions by Monte Carlo method

    International Nuclear Information System (INIS)

    Todo, A.S.

    1980-01-01

    Presently, the estimates of specific absorbed fractions in various organs of a heterogeneous phantom are based on Monte Carlo calculation for monoenergetic photons uniformly distributed in the organs of an adult phantom. But, it is known that the kidney and some other organs (for example the skeleton) do not retain the radionuclides in an uniform manner in its internal region. So, we developed a model for the kidney including the cortex, medulla and collecting region. This model was utilized to estimate the specific absorbed fractions, for monoenergetic photons or electrons, in various organs of a heterogeneous phantom, when sources were uniformly distributed in each region of the kidney. All results obtained in this work were compared with those using a homogeneous model for the kidney as presented in ORNL-5000. (Author) [pt

  11. Prolongation of experimental islet transplant survival by fractionated splenic irradiation

    International Nuclear Information System (INIS)

    Kolb, E.; Casanova, M.; Largiader, F.

    1980-01-01

    Experiments designed to delay the rejection of intrasplenic pancreatic fragment allotransplants in dogs showed increased transplant survival times from 3.1 days (controls) to 5.5 days with fractionated splenic irradiation and to 7.5 days with combined local irradiation and immunosuppressive chemotherapy. Drug treatment alone had no beneficial effect

  12. Fabrication and characterization of absorber pellets for FFTF irradiation testing

    International Nuclear Information System (INIS)

    Wilson, C.N.; Hollenberg, G.W.

    1981-01-01

    Methods used for characterization of B 4 C powder and fabricated pellets are summarized. Fabrication techniques used at HEDL for absorber test pellets are reviewed and selected powder and pellet characterization data are presented

  13. Assessment of specific absorbed fractions for photons and electrons using average adult Japanese female phantom

    International Nuclear Information System (INIS)

    Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

    2016-12-01

    In the 2007 Recommendations of the International Commission on Radiological Protection (ICRP), the procedure for calculating effective doses was modified as follows. Equivalent doses are evaluated using the male and female voxel phantoms on the basis of reference anatomical data of Caucasians, and effective doses are calculated using sex-averaged equivalent doses in applying tissue weighting factors. Specific absorbed fractions (SAFs), which are essential data for calculating internal doses, depend on the body weights, organ masses, and positional relations of organs of the phantoms. Then, the dose coefficients, which are committed effective doses per unit intake of radionuclides, developed by ICRP on the basis of the 2007 Recommendations reflect the physical characteristics of Caucasians and are averaged over the sexes. Meanwhile, the physiques of adult Japanese are generally smaller than those of adult Caucasians, and organ masses are also different from each other. Therefore, dose coefficients reflecting Japanese physical characteristics are different from those of ICRP. Knowledge of the influence of race differences on dose coefficients is important to apply the sex averaged dose coefficients of ICRP to the Japanese system of radiation protection. SAF data based on phantoms which have Japanese physical characteristics is essential for assessment of the dose coefficients reflecting Japanese physical characteristics. The Japan Atomic Energy Agency constructed average adult Japanese phantoms, JM-103 (male) and JF-103 (female), and is developing a dose estimation method for internal exposure using these phantoms. This report provides photon and electron SAFs of JF-103. The data of this report and the previously published data of JM-103 are applicable to evaluate sex-specific and sex-averaged dose coefficients reflecting the physical characteristics of the average adult Japanese for intakes of radionuclides emitting photons and electrons. Appendix as CD-ROM. (J.P.N.)

  14. Internal friction in irradiated silicon

    International Nuclear Information System (INIS)

    Kalanov, M.U.; Pajzullakhanov, M.S.; Khajdarov, T.; Ummatov, Kh.

    1999-01-01

    The submicroscopic heterogeneities in mono- and polycrystal silicon and the influence of X-ray radiation on them were investigated using the ultrasound resonance method. Disk-shaped samples of 27.5 mm in diameter and 4 mm in thickness, with the flat surface parallel to crystallographic plane (111), were irradiated by X-ray beam of 1 Wt/cm 2 (50 KeV, Mo K α ) during 10 hours. Relations of internal frictions (Q -1 ) of samples and their relative attitude (ψ) - Q -1 (ψ) show that there is a presence of double-humped configuration for monocrystal silicon with the peaks at ψ=900 and 270 degrees. The relations Q -1 (ψ) remain the same after the irradiation. However, the peak width becomes larger. This data show that the configuration and attitude of the heterogeneities remain the same after the irradiation. The double-humped configuration was not discovered for the relations Q -1 (ψ) of polycrystal silicon. It is explained by the fact that there is an isotropic distribution in the content of many blocks and granules

  15. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    International Nuclear Information System (INIS)

    Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji

    1999-01-01

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  16. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji [Kochi Medical School, Nankoku (Japan)

    1999-05-01

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  17. Thyroid tumours following fractionated irradiation in childhood

    International Nuclear Information System (INIS)

    Vathaire, F. de; Grimaud, E.; Diallo, I.; Shamsaldin, A.

    1997-01-01

    Results of a cohort study designed to evaluate the long term risk of thyroid tumours after fractioned high doses of external beam radiotherapy received by the thyroid are reported. In this cohort study, doses have been estimated for each child. (author)

  18. Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetry and ends of comparison of the fractions absorbed specific with the woman reference; Modelagem computacional do manequim matematico da mulher brasileira para calculos de dosimetria interna e para fins de comparacao das fracoes absorvidas especificas com a mulher referencia

    Energy Technology Data Exchange (ETDEWEB)

    Ximenes, Edmir

    2006-07-01

    Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97{sup R} computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF - consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several 'look-up' facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them. (author)

  19. Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetry and ends of comparison of the fractions absorbed specific with the woman reference; Modelagem computacional do manequim matematico da mulher brasileira para calculos de dosimetria interna e para fins de comparacao das fracoes absorvidas especificas com a mulher referencia

    Energy Technology Data Exchange (ETDEWEB)

    Ximenes, Edmir

    2006-07-01

    Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97{sup R} computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF - consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several 'look-up' facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them. (author)

  20. Estimating Solar Irradiation Absorbed by Photovoltaic Panels with Low Concentration Located in Craiova, Romania

    Directory of Open Access Journals (Sweden)

    Ionel L. Alboteanu

    2015-03-01

    Full Text Available Solar irradiation is one of the important parameters that should be taken into consideration for the design and utilization of a photovoltaic system. Usually, the input parameters of a photovoltaic system are solar irradiation, the ambient environment temperature and the wind speed, and as a consequence most photovoltaic systems are equipped with sensors for measuring these parameters. This paper presents several mathematical models for solar irradiation assessment. The starting point is represented by the mathematical model of extraterrestrial irradiation, and resulting finally in the model for solar irradiation, absorbed by a low concentration photovoltaic panel. These estimating models of solar irradiation have been particularized for the Craiova, Romania, and have been verified through numerical simulation. Regarding terrestrial solar irradiation, four mathematical models have been adopted, namely Adnot, Haurwitz, Kasten and Empirical (EIM. Of these, the most appropriate for the Craiova location were the models Adnot and Empirical. Consequently, for the calculation of the solar irradiation absorbed by the photovoltaic (PV panels with low concentration, these models have been taken into consideration. In this study, a comparative analysis was also carried out with respect to the solar irradiation absorbed by the PV panels without concentration and those with collectedness of the solar radiation. This analysis was based on the results of numerical simulation and experimental tests.

  1. Estimation of the absorbed dose in gamma irradiated food containing bone by electron spin resonance spectroscopy

    International Nuclear Information System (INIS)

    Basfar, A.A.; Abdel Rehim, F.

    1997-01-01

    The use of electron spin resonance (ESR) spectroscopy to accurately evaluate the absorbed dose to radiationprocessed bones (and thus meats) is examined. The exposure of foodstuffs containing bone to a dose of ionizing radiation results in the formation of long lived free radicals which give rise to characteristics ESR signals. The yield of radicals was found to be proportional to absorbed dose. Additive re-irradiation of previously irradiated bone was used to estimate the absorbed dose in the irradiated chicken bone. Simple non-linear rational equation was found to fit to the data and yields good dose estimates for irradiated bone in the range of doses (1.0 - 5.0 kGy). Decay of the ESR signal intensity was monitored at different dose levels (2.0 and 7.0 kGy) up to 22 days. The absorbed dose in irradiated chicken (2.Om 3.0 and 6.0 kGy) was assessed at 2, 6 and 12 days after irradiation. Relatively good results were obtained when measurements were made within the following days (up to 12 days) after irradiation. The ability of the dose additive method to provide accurate dose assessments is tested here

  2. Traversal of cells by radiation and absorbed fraction estimates for electrons and alpha particles

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Ryman, J.C.; Taner, A.C.; Kerr, G.D.

    1986-01-01

    Consideration of the pathlength which radiation traverses in a cell is central to algorithms for estimating energy deposition on a cellular level. Distinct pathlength distributions occur for radionuclides: (1) uniformly distributed in space about the cell (referred to as μ-randomness); (2) uniformly distributed on the surface of the cell (S-randomness); and (3) uniformly distributed within the cell volume (I-randomness). For a spherical cell of diameter d, the mean pathlengths are 2/3d, and 3/4d, respectively, for these distributions. Algorithms for simulating the path of radiation through a cell are presented and the absorbed fraction in the cell and its nucleus are tabulated for low energy electrons and alpha particles emitted on the surface of spherical cells. The algorithms and absorbed fraction data should be of interest to those concerned with the dosimetry of radionuclide-labeled monoclonal antibodies. 8 references, 3 figures, 2 tables

  3. Traversal of cells by radiation and absorbed fraction estimates for electrons and alpha particles

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Ryman, J.C.; Taner, A.C.; Kerr, G.D.

    1985-01-01

    Consideration of the pathlength which radiation traverses in a cell is central to algorithms for estimating energy deposition on a cellular level. Distinct pathlength distributions occur for radionuclides: (1) uniformly distributed in space about the cell (referred to as μ-randomness); (2) uniformly distributed on the surface of the cell (S-randomness); and (3) uniformly distributed within the cell volume (I-randomness). For a spherical cell of diameter d, the mean pathlengths are 2/3d, 1/2d, and 3/4d, respectively, for these distributions. Algorithms for simulating the path of radiation through a cell are presented and the absorbed fraction in the cell and its nucleus are tabulated for low energy electrons and alpha particles emitted on the surface of spherical cells. The algorithms and absorbed fraction data should be of interest to those concerned with the dosimetry of radionuclide-labeled monoclonal antibodies. 8 refs., 3 figs., 2 tabs

  4. Transformation method for the MIRD absorbed fractions as applied to various physiques

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi

    1978-01-01

    This study concerns with the transformation method of the MIRD absorbed fraction (AF) to the AF corresponding to an individual having the dimensions different from those of the MIRD standard man. The absorbed dose of a target organ T from a source organs S, received by the administration of a radiopharmaceutical agent is expressed with the equilibrium absorbed dose constant, the cumulative activity in the S, and the specific absorbed fraction (SAF). It is dealt only with how the MIRD SAF data can be modified for estimating individual SAF values. The SAF for individuals is given for penetrating and non-penetrating radiations. In case of the penetrating radiation, the SAF is given from the corresponding MIRD SAF by using a transformation coefficient for the MIRD SAF, when the MIRD standard man is transfigured to a corresponding phantom of an individual by the scale factors selected separately for the head section, trunk section and leg section of the MIRD standard man. The obtained results were compared with the ORNL results, and showed good agreement. (Kato, T.)

  5. 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

  6. Specific absorbed fractions for photons emitted in the walls of the GI tract

    International Nuclear Information System (INIS)

    Deus, S.F.; Provenzano, V.; Snyder, W.S.

    1978-01-01

    Although the sections of the gastrointestinal tract (GIT) are represented as source organs in MIRD Pamphlet No. 5, the wall and contents were not separated in the model. Thus, the absorbed fractions given in that publication are perhaps more representative of the contents than of the wall. A new model is given in ORNL-5000 where the contents and the wall defined separately but only absorbed fractions (or specific absorbed fractions) are given for the source in the contents. Specific absorbed fractions for the source uniformly distributed in the wall of each of the three sections of the tract, namely, stomach, upper large intestine and lower large intestine are given. The same 12 energies are used for the sources as in the other publications and data are given for all target organs included previously. Each computer run used a sample of 60,000 photons and all calculations were done at the IEA at Sao Paulo, Brazil. When the statistics of the estimate are poor, a value obtained by use of Berger s build-up factor is substituted. Thus, a complete table of values is obtained. Activity in the walls of the tract has been reported for gallium and a check on the dose values reported by Cloutier et al. (MIRD73) reveals that the comulated activity (μCi-days) in the contents overwhelms those from the tract and the total dose from the tract and the total dose values are not greatly affected. However, differences of a factor of 2 or 3 are present when considering the contribution from activity in the walls alone

  7. Electron beam dosimetry for a thin-layer absorber irradiated by 300-keV electrons

    International Nuclear Information System (INIS)

    Kijima, Toshiyuki; Nakase, Yoshiaki

    1993-01-01

    Depth-dose distributions in thin-layer absorbers were measured for 300-keV electrons from a scanning-type irradiation system, the electrons having penetrated through a Ti-window and an air gap. Irradiations of stacks of cellulose triacetate(CTA) film were carried out using either a conveyor (i.e. dynamic irradiation) or fixed (i.e. static) irradiation. The sample was irradiated using various angles of incidence of electrons, in order to examine the effect of obliqueness of electron incidence at low-energy representative of routine radiation curing of thin polymeric or resin layers. Dynamic irradiation gives broader and shallower depth-dose distributions than static irradiation. Greater obliqueness of incident electrons gives results that can be explained in terms of broader and shallower depth-dose distributions. The back-scattering of incident electrons by a metal(Sn) backing material enhances the absorbed dose in a polymeric layer and changes the overall distribution. It is suggested that any theoretical estimations of the absorbed dose in thin layers irradiated in electron beam curing must be accomplished and supported by experimental data such as that provided by this investigation. (Author)

  8. Research on temperature characteristics of laser energy meter absorber irradiated by ms magnitude long pulse laser

    Science.gov (United States)

    Li, Nan; Qiao, Chunhong; Fan, Chengyu; Zhang, Jinghui; Yang, Gaochao

    2017-10-01

    The research on temperature characteristics for large-energy laser energy meter absorber is about continuous wave (CW) laser before. For the measuring requirements of millisecond magnitude long pulse laser energy, the temperature characteristics for absorber are numerically calculated and analyzed. In calculation, the temperature field distributions are described by heat conduction equations, and the metal cylinder cavity is used for absorber model. The results show that, the temperature of absorber inwall appears periodic oscillation with pulse structure, the oscillation period and amplitude respectively relate to the pulse repetition frequency and single pulse energy. With the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and rises gradually with time. The factors to affect the temperature rise of absorber are single pulse energy, pulse width and repetition frequency. When the laser irradiation stops, the temperature between absorber inwall and outerwall will reach agreement rapidly. After special technology processing to enhance the capacity of resisting laser damage for absorber inwall, the ms magnitude long pulse laser energy can be obtained with the method of measuring the temperature of absorber outerwall. Meanwhile, by optimization design of absorber structure, when the repetition frequency of ms magnitude pulse laser is less than 10Hz, the energy of every pulse for low repetition frequency pulse sequence can be measured. The work offers valuable references for the design of ms magnitude large-energy pulse laser energy meter.

  9. Absorbed dose distribution analyses in irradiation with adjacent fields

    International Nuclear Information System (INIS)

    Cudalbu, C.; Onuc, C.; Andrada, S.

    2002-01-01

    Because the special irradiation technique with adjacent fields is the most used in the case of medulloblastoma treatment, we consider very important to specify some general information about medulloblastoma. This malignant disease has a large incidence in children with age between 5-7 years. This tumor usually originates in the cerebellum and is referred to as primitive undifferentiated tumor. It may spread contiguously to the cerebellar peduncle, floor of the fourth ventricle, into the cervical spine. In addition, it may spread via the cerebrospinal fluid intracranially and/or to the spinal cord. For this purpose it is necessary to perform a treatment technique with cranial tangential fields combined with adjacent fields for the entire spinal cord to achieve a perfect coverage of the zones with malignant cells. The treatment in this case is an association between surgery-radio-chemotherapy, where the radiotherapy has a very important roll and a curative purpose. This is due to the fact that the migration of malignant cells in the body can't be controlled by surgery. Because of this special irradiation technique used in medulloblastoma treatment, we chase to describe in this paper this complex type of irradiation where the implications of the beams divergence in doses distribution are essentials

  10. Acute skin reactions observed in fractionated proton irradiation

    International Nuclear Information System (INIS)

    Arimoto, Takuro; Maruhashi, Noboru; Takada, Yoshihisa; Hayakawa, Yoshinori; Inada, Tetsuo; Kitagawa, Toshio

    1989-01-01

    Between May 1985 and July 1987, 49 skin reactions of 43 patients treated by proton irradiation were observed at the Particle Radiation Medical Science Center (PARMS), the University of Tsukuba. Taking the peak skin score as an endpoint, the radiobiological effects [relative biological effectiveness (RBE) and time-dose relationship] of the proton beam in multi-fractionated treatments were estimated. Factors influencing the skin dose, such as the prescribed tumor dose, tumor site, and number of applied fields, were also analyzed. The following conclusions regarding acute skin reactions to the clinical use of proton irradiation were obtained: 1) the physical skin-sparing effect of proton irradiation in single-field irradiation, especially in superficial regions, is not large compared with that of high-energy photon irradiation; 2) multidirectional proton irradiation significantly reduced the skin dose and severity of acute reasons; 3) the radiobiological effects of the proton beam, RBE and the time factor, estimated in human skin in multi-fractional treatment were slightly smaller than those of X-rays, i.e., 0.92 and -0.25±0.09, respectively. (author)

  11. Mouse skin damages caused by fractionated irradiation with carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K; Chen, Y J; Ohira, C; Nojima, K; Ando, S; Kobayashi, N; Ohbuchi, T; Shimizu, W [Space and Particle Radiation Science Research Group, Chiba (Japan); Koike, S; Kanai, T [National Inst. of Radiological Sciences, Chiba (Japan). Div. of Accelerator Physics

    1997-09-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/{mu}m also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/{mu}m in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/{mu}m were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/{mu} steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  12. Mouse skin damages caused by fractionated irradiation with carbon ions

    International Nuclear Information System (INIS)

    Ando, K.; Chen, Y.J.; Ohira, C.; Nojima, K.; Ando, S.; Kobayashi, N.; Ohbuchi, T.; Shimizu, W.; Koike, S.; Kanai, T.

    1997-01-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/μm also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/μm in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/μm were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/μ steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  13. ESR spectroscopy for detecting gamma-irradiated dried vegetables and estimating absorbed doses

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joong-Ho; Chung, Hyung-Wook; Byun, Myung-Woo

    2000-03-01

    In view of an increasing demand for food irradiation technology, the development of a reliable means of detection for the control of irradiated foods has become necessary. Various vegetable food materials (dried cabbage, carrot, chunggyungchae, garlic, onion, and green onion), which can be legally irradiated in Korea, were subjected to a detection study using ESR spectroscopy. Correlation coefficients (R{sup 2}) between absorbed doses (2.5-15 kGy) and their corresponding ESR signals were identified from ESR signals. Pre-established threshold values were successfully applied to the detection of 54 coded unknown samples of dried clean vegetables (chunggyungchae, Brassica camestris var. chinensis), both non-irradiated and irradiated. The ESR signals of irradiated chunggyungchae decreased over a longer storage time, however, even after 6 months of ambient storage, these signals were still distinguishable from those of non-irradiated samples. The most successful estimates of absorbed dose (5 and 8 kGy) were obtained immediately after irradiation using a quadratic fit with average values of 4.85 and 8.65 kGy being calculated. (author)

  14. Hypo fractionated conformal irradiation of patients with malignant glioma

    International Nuclear Information System (INIS)

    Aboziada, M.A.; Abo-Kresha, A.E.

    2012-01-01

    Purpose: The aim of the study is to evaluate the effect of a conformal irradiation in short fractionation scheme of 49.5 Gy in 15 fractions in an overall time of 3 weeks, in terms of overall survival (OAS) and progression free survival (PFS) rates in brain glioma patients. Patients and methods: A prospective study was conducted on 54 brain glioma patients and was carried out in the Radiation Oncology Department, South Egypt Cancer Institute, Assiut University during the period from April 2006 till June 2009. Patients were treated by hypo fractionated conformal irradiation (49.5 Gy/15 fractions/3 weeks). Results: The median follow up was 23 months (range: 9-39 months). Two-year OAS and PFS rates were 68% and 60%, respectively. In univariate analysis, age > 50 years, poor performance status [Karnofasky score of >40- 50 years and glioblastoma pathology were the only independent prognostic factors that were associated with poor OAS (p = 0.003 and p = 0.004, respectively), and PFS (p = 0.027 and p = 0.011, respectively). Conclusion: Hypo fractionated conformal radiotherapy was as effective as the conventional radiotherapy, with time sparing for patients, and for radiation oncology centers. Hypo fractionated radiotherapy may be considered the radiotherapy regimen of choice in clinical practice for patients with gliomas

  15. Assessment of specific absorbed fractions for photons and electrons using average adult Japanese male phantom

    International Nuclear Information System (INIS)

    Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

    2014-10-01

    The International Commission on Radiological Protection (ICRP) is revising dose coefficients, which are effective and equivalent doses per unit intake of radionuclides, based on the 2007 Recommendations. Specific absorbed fractions (SAFs) of voxel phantoms having standard physiques and organ masses (physical characteristics) of Caucasian are used for calculation of the new dose coefficients. SAFs depend on physical characteristics of a phantom used for assessment of the SAFs. Therefore, the SAFs and the dose coefficients developed by ICRP reflect physical characteristics of Caucasian. On the other hand, physiques of adult Japanese are generally smaller than those of adult Caucasian, and organ masses are also different from each other. Consequently, it is expected that SAFs and dose coefficients with physical characteristics of adult Japanese are different from those of ICRP. It is important to understand the influence of the differences in physical characteristics between both races on SAFs and dose coefficients when using the SAFs and dose coefficients of ICRP for radiation protection for Japanese. In order to evaluate internal doses considering the physical characteristics of adult Japanese, the Japan Atomic Energy Agency plans to develop a comprehensive data set of SAFs for photons, electrons, alpha particles and neutrons using average adult Japanese male and female phantoms (male: JM-103, female: JF-103). This report presents a data set of photon and electron SAFs for JM-103. JM-103 was incorporated into the general purpose radiation transport code, MCNPX 2.6.0, and the SAFs were calculated by the MCNPX 2.6.0 for 25 energies from 10 keV to 10 MeV and for combinations of 67 source regions and 41 target organs. Influences of differences in physical characteristics between adult Japanese and Caucasian on SAFs was also examined by comparison between the calculated SAFs in this study and the SAFs of the reference adult male phantom of ICRP. The photon and electron

  16. Intestinal complications following accelerated fractionated X-irradiation

    International Nuclear Information System (INIS)

    Hauer-Jensen, M.; Poulakos, L.; Osborne, J.W.

    1990-01-01

    Due to paucity of suitable animal models, it has been difficult to study the development of long-term intestinal complications following fractionated irradiation. We recently developed a model which allows multiple radiation exposures of a short segment of rat ileum without the need for repeated surgery. In the present series, this model was used to study the influence of shortening the total treatment time (accelerated fractionation) on development of radiation enteropathy. Male rats were orchiectomized and a short segment of distal ileum was transposed to the scrotum. Starting 3 weeks after surgery, the scrotum containing the intestinal segment was X-irradiated with 20 fractions of 2.8 Gy (total dose 56 Gy). Two fractionation schedules were compared: one fraction per day (total treatment time 26 days) and 3 fractions per day (total treatment time 7 days). Actuarial survival curves were obtained, and the degree of radiation injury was assessed 2, 8 and 26 weeks after the last radiation exposure using a semiquantitative histopathologic scoring system. There was no mortality from acute radiation injury in either treatment group. All animals of the 1-fraction/day group survived the observation period (26 weeks). In the 3-fraction/day group, there was significant mortality due to intestinal obstruction, and cumulative mortality at 26 weeks was 100%. Radiation injury, as assessed by the histopathologic scoring system, was also more pronounced in this group than in the 1-fraction/day group. We conclude that shortening the total treatment time significantly increases the severity of late intestinal complications. Our data are suggestive of an association between acute mucosal damage and chronic radiation injury of the small intestine. (orig.)

  17. Ultrastructural morphometry of parotid acinar cells following fractionated irradiation

    International Nuclear Information System (INIS)

    Grehn, A.-L.; Gustafsson, H.; Franzen, L.; Thornell, L.-E.; Henriksson, R.

    1997-01-01

    The aim of this study was to evaluate the long term effects on the ultrastructure of parotid glands after fractionated irradiation. The method implemented involved 5 x 6 Gy and 5 x 8 Gy, Monday to Friday 6 MV photons. By unilateral irradiation, the contralateral parotid gland served as a control. Although irradiation diminished the acinar cell density in light microscopic sections from 75 to 32% after 5 x 8 Gy of irradiation, ultrastructural morphometry could not detect any statistically significant differences in acinar cell size, nuclear size, nuclear density, granule area, mean granule size, or granule density. In general, greater differences were seen between rats receiving 30 or 40 Gy, on both the irradiated and the control side, than between the irradiated side and the control side. This was interpreted as due to differences in the nutritional state of the animals. This analysis concluded that individual acinar cells that survive irradiation seem not to be damaged in the long term when evaluated at the ultrastructural level. The study further stresses the importance of adequate sampling sizes and the use of adequate controls. (author)

  18. Effects of genistein following fractionated lung irradiation in mice

    International Nuclear Information System (INIS)

    Para, Andrea E.; Bezjak, Andrea; Yeung, Ivan W.T.; Van Dyk, Jake; Hill, Richard P.

    2009-01-01

    Background and purpose: This study investigated protection of lung injury by genistein following fractionated doses of radiation and its effect on tumor response. Material and methods: C3H/HeJ mice were irradiated (100 kVp X-rays) with 9 fractions of 3.1 Gy over 30 days (approximately equivalent to 10 Gy single dose) and were maintained on a genistein diet (∼10 mg/kg). Damage was assessed over 28 weeks in lung cells by a cytokinesis block micronucleus (MN) assay and by changes in breathing rate and histology. Tumor protection was assessed using a colony assay to determine cell survival following in situ irradiation of small lung nodules (KHT fibrosarcoma). Results: Genistein caused about a 50% reduction in the MN damage observed during the fractionated radiation treatment and this damage continued to decrease at later times to background levels by 16 weeks. In mice not receiving Genistein MN levels remained well above background out to 28 weeks after irradiation. Genistein reduced macrophage accumulation by 22% and reduced collagen deposition by 28%. There was minimal protection against increases in breathing rate or severe morbidity during pneumonitis. No tumor protection by genistein treatment was observed. Conclusions: Genistein at the dose levels used in this study partially reduced the extent of fibrosis developing in mouse lung caused by irradiation but gave minimal protection against pneumonitis. There was no evidence that genistein caused protection of small tumors growing in the lung.

  19. International comparison of calibration standards for exposure and absorbed dose

    International Nuclear Information System (INIS)

    Horakova, I.; Wagner, R.

    1990-01-01

    A comparison was performed of the primary calibration standards for 60 Co gamma radiation dose from Czechoslovakia (UDZ CSAV, Prague), Austria (OEFZS/BEV Seibersdorf) and Hungary (OMH Budapest) using ND 1005 (absolute measurement) and V-415 (by means of N x ) graphite ionization chambers. BEV achieved agreement better than 0.1%, OMH 0.35%. Good agreement was also achieved for the values of exposure obtained in absolute values and those obtained via N x , this for the ND 1005/8105 chamber. The first ever international comparison involving Czechoslovakia was also performed of the unit of absorbed gamma radiation in a water and/or graphite phantom. The participants included Czechoslovakia (UDZ CSAV Prague), the USSR (VNIIFTRI Moscow) and Austria (OEFZS/BEV Seibersdorf). In all measurements, the agreement was better than 1%, which, in view of the differences in methodologies (VNIIFTRI, BEV: calorimetry, UDZ, UVVVR: ionometry) and the overall inaccuracies in determining the absorbed dose values, is a good result. (author)

  20. Prospects of international trade in irradiated foods

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1990-01-01

    Irradiation is gaining recognition as a physical process for reducing food losses, enhancing hygienic quality of food and facilitating food trade. At present, 36 countries have approved the use of irradiation for processing collectively over 40 food items either on an unconditional or restricted basis. Commercial use of irradiated foods and food ingredients is being carried out in 22 countries. Technology transfer on food irradiation is being intensified to local industry in different regions. Worldwide, a total of 40 commercial/demonstration irradiators available for treating foods have been or are being constructed. Acceptance and control of international trade in irradiated foods were discussed at the International Conference on the Acceptance, Control of and Trade in Irradiated Food, jointly convened by FAO, IAEA, WHO and ITC-UNCTAD/GATT in Geneva, Switzerland, 12-16 December 1988. An ''International Document on Food Irradiation'' was adopted by consensus at this Conference which will facilitate wider acceptance and control of international trade in irradiated foods. (author)

  1. Spatial distribution of absorbed dose onboard of International Space Station

    International Nuclear Information System (INIS)

    Jadrnickova, I.; Spumy, F.; Tateyama, R.; Yasuda, N.; Kawashima, H.; Kurano, M.; Uchihori, Y.; Kitamura, H.; Akatov, Yu.; Shurshakov, V.; Kobayashi, I.; Ohguchi, H.; Koguchi, Y.

    2009-01-01

    The passive detectors (LD and PNTD) were exposed onboard of Russian Service Module Qn the International Space Station (ISS) from August 2004 to October 2005 (425 days). The detectors were located at 6 different positions inside the Service Module and also in 32 pockets on the surface of the spherical tissue-equivalent phantom located in crew cabin. Distribution of absorbed doses and dose equivalents measured with passive detectors, as well as LET spectra of fluences of registered particles, are presented as the function of detectors' location. The variation of dose characteristics for different locations can be up to factor of 2. In some cases, data measured with passive detectors are also compared with the data obtained by means of active instruments. (authors)

  2. Therapeutic use of fractionated total body and subtotal body irradiation

    International Nuclear Information System (INIS)

    Loeffler, R.K.

    1981-01-01

    Ninety-one patients were treated using fractionated subtotal body (STBI) or total body irradiation (TBI). These patients had generalized lymphomas, Hodgkin's disease, leukemias, myelomas, seminomas, or oat-cell carcinomas. Subtotal body irradiation is delivered to the entire body, except for the skull and extremities. It was expected that a significantly higher radiation dose could be administered with STBI than with TBI. A five- to ten-fold increase in tolerance for STBI was demonstrated. Many of these patients have had long-term emissions. There is little or no treatment-induced symptomatology, and no sanctuary sites

  3. NOAA Climate Data Record (CDR) of Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), Version 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains gridded daily Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) derived from the NOAA Climate Data...

  4. Analytical formulae in fractionated irradiation of normal tissue

    International Nuclear Information System (INIS)

    Kozubek, S.

    1982-01-01

    The new conception of the modeling of the cell tissue kinetics after fractionated irradiation is proposed. The formulae given earlier are compared with experimental data on various normal tissues and further adjustments are considered. The tissues are shown to exhibit several general patterns of behaviour. The repopulation, if it takes place, seems to start after some time, independently of fractionation in first approximation and can be treated as simple autogenesis. The results are compared with the commonly used NSD conception and the well-known Cohen cell tissue kinetic model

  5. Immunosuppression by fractionated total lymphoid irradiation in collagen arthritis

    International Nuclear Information System (INIS)

    McCune, W.J.; Buckley, J.A.; Belli, J.A.; Trentham, D.E.

    1982-01-01

    Treatments with fractionated total lymphoid irradiation (TLI) and cyclophosphamide were evaluated for rats injected with type II collagen. Preadministration of TLI and repeated injections of cyclophosphamide suppressed the severity of arthritis and lowered antibody titers to collagen significantly. TLI initiated at the onset of collagen arthritis decreased humoral and cellular responses to collagen but did not affect the severity of arthritis. These data demonstrate that both TLi and cyclophosphamide are immunosuppressive in an experimentally inducible autoimmune disease

  6. Effects of carbogen plus fractionated irradiation on KHT tumor oxygenation

    International Nuclear Information System (INIS)

    Fenton, Bruce M.

    1997-01-01

    Background and purpose: Numerous studies have demonstrated improvements in the oxygenation of tumor cells following both irradiation and carbogen breathing. The current studies were initiated to measure the combined effects of carbogen inhalation plus single and multi-dose irradiation on tumor oxygen availability, to better define the underlying physiological relationships. Materials and methods: Using KHT murine sarcomas, radiation was delivered to the tumor-bearing legs of non-anesthetized mice. Tumors were quick-frozen prior to or following single or multifraction irradiation and carbogen breathing, and intravascular HbO 2 saturation profiles were determined cryospectrophotometrically. Results: HbO 2 levels for blood vessels located near the tumor surface initially decreased following 10 Gy irradiation, then increased and remained elevated. Interior HbO 2 levels remained unchanged. Following 2.5 Gy, HbO 2 changes were minimal. At 24 h following 10 Gy, HbO 2 levels were significantly increased compared to non-irradiated controls, and carbogen breathing produced no additional benefit. At 24 h following five fractions of 2 Gy, HbO 2 levels throughout the tumor volume were significantly higher in carbogen breathing animals than in air breathing controls. Conclusions: Although peripheral blood vessels demonstrated substantial improvements in oxygenation following irradiation, oxygen availability nearer the tumor center remained at very low levels. The utility of carbogen in enhancing tumor oxygen availability was maintained following five clinically relevant fractions. At higher doses, radiation-induced enhancements in HbO 2 levels overshadowed the carbogen effect. For either air or carbogen breathing, a decrease in the percentage of vessels with very low oxygen content did not appear to be a major factor in the reoxygenation of the KHT tumor

  7. Radiotherapy. Non-standard fractionated regimens improving cancer treatment. Part II. Response of normal tissues to fractionated irradiation

    International Nuclear Information System (INIS)

    Villar, A.; Hernandez, M.; Pera, J.; Cambray, M.; Villa, S.; Arnaiz, M.D.

    1988-01-01

    The phenomena participating in the response of tissues to fractionated irradiation are analyzed with special emphasis on the most relevant points influencing the design of non-standard fractionated regimens. (Author)

  8. Radioresistance and immunization effectiveness under internal irradiation

    International Nuclear Information System (INIS)

    Kal'nitskij, S.A.

    1978-01-01

    The effect of preliminary immunization on the radioresistance of mice to internal irradiation from incorporated 137 Cs or 90 Sr was studied, and it was found that a preliminary single immunization with bacterial vaccines had a favorable effect on the outcome of radiation injury. The present results suggested that vaccination had a very pronounced radioprotective effect and so may be used as a means of biologic protection from internal irradiation

  9. Absorbed dose to mice in prolonged irradiation by low-dose rate ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shiragai, Akihiro [National Inst. of Radiological Sciences, Chiba (Japan); Saitou, Mikio; Kudo, Iwao [and others

    2000-07-01

    In this paper, the dose absorbed by mice was evaluated as a preliminary study of the late effects of prolonged continuous irradiation of mice with low-dose rate ionizing radiation. Eight-week-old male and female SPF C3H/HeN mice in three irradiation rooms were exposed to irradiation at 8000, 400, and 20 mGy, respectively, using a {sup 137}Cs {gamma}-source. Nine racks were arranged in a circle approximately 2.5 m from the source in each room, and 10 cages were arranged on the 4 shelves of each rack. Dose distributions, such as in air at the source level, in the three rooms were estimated by using ionization chambers, and the absorbed dose distributions in the room and relative dose distributions in the cages in relation to the distance of the cage center were examined. The mean abdomen doses of the mice measured by TLD were compared with the absorbed doses in the cages. The absorbed dose distributions showed not only inverse-inverse-square-law behavior with distance from the source, but geometric symmetry in every room. The inherent scattering and absorption in each room are responsible for such behavior and asymmetry. Comparison of relative dose distributions revealed cage positions that are not suitable for experiments with high precision doses, but all positions can be used for prolonged continuous irradiation experiments if the position of the cages is rotated regularly. The mean abdomen doses of the mice were similar in each cage. The mean abdomen doses of the mice and the absorbed doses in a cage were almost the same in all cages. Except for errors concerning the positions of the racks and cages, the uncertainties in the exposure doses were estimated to be about {+-}12% for 8000 mGy group, 17% for 400 mGy group, and 35% for 20 mGy group. (K.H.)

  10. International Facility for Food Irradiation Technology

    International Nuclear Information System (INIS)

    Farkas, J.

    1982-01-01

    The International Facility for Food Irradiation Technology (IFFIT) was set up in November 1978 for a period of five years at the Pilot Plant for Food Irradiation, Wageningen, The Netherlands under an Agreement between the FAO, IAEA and the Ministry of Agriculture and Fisheries of the Government of the Netherlands. Under this Agreement, the irradiation facilities, office space and services of the Pilot Plant for Food Irradiation are put at IFFIT's disposal. Also the closely located Research Foundation, ITAL, provides certain facilities and laboratory services within the terms of the Agreement. The FAO and IAEA contribute US-Dollar 25,000. Annually for the duration of IFFIT. (orig.) [de

  11. International acceptance of irradiated food. Legal aspects

    International Nuclear Information System (INIS)

    1979-01-01

    The three international organizations competent in the field of irradiation processing for the preservation of food (FAO, WHO, IAEA), convened, at the end of 1977, an Advisory Group to revise and update the recommendations of a similar group which met in early 1972. The Advisory Group considered how national regulations could be harmonized so as to facilitate the international movement of irradiated food. This publication contains the Report of the Advisory Group, which summarizes the considerations of the Group on regulatory control over the irradiation plant and irradiation of foods, and on assurances for comparability of control (international labelling and documentation). Annexes 1 to 6 are included in order to complete the relevant information on the legal aspects of this subject. They include a Draft General Standard for Irradiated Foods, a Draft Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Foods, Recommendations of a Consultation Group on the Legal Aspects of Food Irradiation, a Listing of the Legislation on Food Irradiation Adopted in Member States (1971-1976), and Model Regulations for the Control of and Trade in Irradiated Food

  12. Tumor oxygenation in a transplanted rat rhabdomyosarcoma during fractionated irradiation

    International Nuclear Information System (INIS)

    Zywietz, Friedrich; Reeker, Wolfram; Kochs, Eberhard

    1995-01-01

    Purpose: To quantify the changes in tumor oxygenation in the course of a fractionated radiation treatment extending over 4 weeks. Methods and Materials: Rhabdomyosarcomas R1H of the rat were irradiated with 60 Co-γ-rays with a total dose of 60 Gy, given in 20 fractions over 4 weeks. Oxygen partial pressure (pO 2 ) in tumors was measured at weekly intervals using polarographic needle probes in combination with a microprocessor-controlled device (pO 2 -Histograph/KIMOC). The pO 2 measurements were carried out in anesthetized animals under mechanical ventilation and in respiratory and hemodynamic steady state. Tumor pO 2 values were correlated to the arterial oxygen pressure p a O 2 , arterial pCO 2 , and pH determined with a blood gas analyzer. Results: Tumor oxygenation did not change significantly during the 3 weeks of irradiation (up to 45 Gy), from a median pO 2 of 23 ± 2 mmHg in untreated controls to 19 ± 4 mmHg after the third week. The decrease of the number of pO 2 values between 0 and 5 mmHg indicated that an improved oxygenation in the tumors occurred. However, with increasing radiation dose (fourth week, 60 Gy) a significant decrease in tumor oxygenation to a median pO 2 of 8 ± 2 mmHg and a rapid increase in the frequency of pO 2 values (35 ± 4%) between 0 and 5 mmHg was found. Conclusion: Improved oxygenation in rhabdomyosarcomas R1H was only present in the early phase of the fractionated irradiation. Radiation doses above 45 Gy led to a considerable decrease of tumor oxygenation in the later phase of irradiation

  13. Response functions for computing absorbed dose to skeletal tissues from neutron irradiation

    Science.gov (United States)

    Bahadori, Amir A.; Johnson, Perry; Jokisch, Derek W.; Eckerman, Keith F.; Bolch, Wesley E.

    2011-11-01

    Spongiosa in the adult human skeleton consists of three tissues—active marrow (AM), inactive marrow (IM) and trabecularized mineral bone (TB). AM is considered to be the target tissue for assessment of both long-term leukemia risk and acute marrow toxicity following radiation exposure. The total shallow marrow (TM50), defined as all tissues lying within the first 50 µm of the bone surfaces, is considered to be the radiation target tissue of relevance for radiogenic bone cancer induction. For irradiation by sources external to the body, kerma to homogeneous spongiosa has been used as a surrogate for absorbed dose to both of these tissues, as direct dose calculations are not possible using computational phantoms with homogenized spongiosa. Recent micro-CT imaging of a 40 year old male cadaver has allowed for the accurate modeling of the fine microscopic structure of spongiosa in many regions of the adult skeleton (Hough et al 2011 Phys. Med. Biol. 56 2309-46). This microstructure, along with associated masses and tissue compositions, was used to compute specific absorbed fraction (SAF) values for protons originating in axial and appendicular bone sites (Jokisch et al 2011 Phys. Med. Biol. 56 6857-72). These proton SAFs, bone masses, tissue compositions and proton production cross sections, were subsequently used to construct neutron dose-response functions (DRFs) for both AM and TM50 targets in each bone of the reference adult male. Kerma conditions were assumed for other resultant charged particles. For comparison, AM, TM50 and spongiosa kerma coefficients were also calculated. At low incident neutron energies, AM kerma coefficients for neutrons correlate well with values of the AM DRF, while total marrow (TM) kerma coefficients correlate well with values of the TM50 DRF. At high incident neutron energies, all kerma coefficients and DRFs tend to converge as charged-particle equilibrium is established across the bone site. In the range of 10 eV to 100 Me

  14. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU

    2015-12-01

    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  15. 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)

  16. Effectiveness of perfluorochemical emulsions and carbogen breathing with fractionated irradiation

    International Nuclear Information System (INIS)

    Moulder, J.E.; Fish, B.L.

    1987-01-01

    Oxygen-carrying perfluorochemical emulsions have been shown to enhance the response of experimental tumors to large single doses of radiation. Clinically, however, perfluorochemical emulsions will be used with only some fractions of multiple fraction radiation courses. To test the efficacy of a perfluorochemical emulsion (Fluosol-DA 20%, supplied by Alpha Therapeutic Co) under these conditions, BA1112 rat sarcomas were treated with three fractions/week of 6.25 Gy/fraction. Once a week, animals were given Fluosol-DA at 15 ml/kg, and allowed to breathe 95% O/sub 2/:5% CO/sub 2/ (carbogen) for 30 min prior to and during irradiation. The tumor regression rate during treatment was significantly greater in the Fluosol arm than in the control arm. Preliminary data analysis shows a 50% tumor control dose of 86.0 Gy (95% cl:78.0 - 94.3 Gy) in the control arm compared to 69.1 Gy (95% cl:58.3 - 77.3 Gy) in the Fluosol arm. The dose modification factor for intermittent Fluosol and carbogen breathing is 1.26 (95% cl:1.08 - 1.50). In the same fractionated schedule 0.4 mg/kg misonidazole, given once per week, gave a sensitizer enhancement ratio of 1.15 (95% cl:1.03 - 1.33)

  17. Performance of compact TES arrays with integrated high-fill-fraction X-ray absorbers

    International Nuclear Information System (INIS)

    Lindeman, Mark A.; Bandler, Simon; Brekosky, Regis P.; Chervenak, James A.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Kelley, Richard L.; Saab, Tarek; Stahle, Caroline K.; Talley, D.J.

    2004-01-01

    We have recently produced and tested two-dimensional arrays of Mo/Au transition-edge-sensor (TES) calorimeters with Bi/Cu absorbers. The arrays represent a significant step towards meeting the specifications of NASA's Constellation-X mission. The calorimeters are compactly spaced within 5x5 arrays of 250 μm square pixels necessary for an angular resolution of 5 arcsec. Lithographically produced absorbers hang over the substrate and wiring between the TESs for high filling fraction and high quantum efficiency. We designed the calorimeters with heat capacities and thermal couplings such that X-rays produce pulses with fall times of approximately 300 μs to allow relatively high count rates with low dead time. We read out up to four of the pixels simultaneously. The arrays demonstrated very good energy resolution (5 eV at 1.5 keV and 7 eV at 6 keV) and little crosstalk between neighboring pixels

  18. New pallet irradiator for Gammaster International

    International Nuclear Information System (INIS)

    Moehlmann, J.H.F.

    1993-01-01

    State of the art technology offers many opportunities to improve production processes with ionizing radiation. Internal and external audits, in particular by regulatory bodies such as the FDA and DHSS/MCA, are necessary and commonplace requirements when operating in the healthcare and pharmaceutical sectors. Efficiency is a major requirement for industry and also for our radiation business. With all the above mentioned items in mind, Gammaster International B.V. has developed and built a new type Pallet Irradiator. For this irradiator Gammaster International designed and built a new process console, incorporating state of the art technology. (author)

  19. How to improve the irradiation conditions for the International Fusion Materials Irradiation Facility

    CERN Document Server

    Daum, E

    2000-01-01

    The accelerator-based intense D-Li neutron source International Fusion Materials Irradiation Facility (IFMIF) provides very suitable irradiation conditions for fusion materials development with the attractive option of accelerated irradiations. Investigations show that a neutron moderator made of tungsten and placed in the IFMIF test cell can further improve the irradiation conditions. The moderator softens the IFMIF neutron spectrum by enhancing the fraction of low energy neutrons. For displacement damage, the ratio of point defects to cascades is more DEMO relevant and for tritium production in Li-based breeding ceramic materials it leads to a preferred production via the sup 6 Li(n,t) sup 4 He channel as it occurs in a DEMO breeding blanket.

  20. Development of a toroidal shell-type shock absorber for an irradiated fuel shipping cask

    International Nuclear Information System (INIS)

    Sugita, Y.; Mochizuki, S.

    1983-01-01

    This study described the design method of a toroidal shell-type shock absorber and the dynamic responses of the cask body, the internal structure and water when this shock absorber was used. Conclusions are: the calculated results on the basis of the master curves of non-dimensionalized force-deflection relations by static compression tests show a close agreement with the experimental results; the internal structure moves together with the cask body in every position; and the maximum water pressure is larger by a factor of 1.2 than the static pressure multiplied by the maximum deceleration in every direction due to the low-frequency wave propagation

  1. The characteristics and mechanism of apoptosis induced by internal irradiation

    International Nuclear Information System (INIS)

    Hong Chengjiao; Zhang Junning; Zhu Shoupeng

    2001-01-01

    Apoptosis in tumor cells induced by radionuclides is likely the most effective way to cure cancer. In order to explore the possibility in clinic application, the characteristics and mechanism of apoptosis induced by internal irradiation were investigated. The apoptosis and expressions of bcl-2mRNA, bcl-2 and bax of K 562 cells following internal exposure with different accumulated absorbed doses of strontium-89 were studied. 6 h after irradiation, the characteristics of apoptosis and necrosis appeared in K 562 cells. The apoptosis and necrosis enhanced with the prolongation of internally contaminated time at 6 h, 9 h, 12 h, 24 h and 48 h. The expressions of bcl-2mRNA decreased at 12 h, most remarkably at 24 h. The expressions of bcl-2 decreased after irradiation whereas bax had no obvious changes. The results suggest that the apoptosis induced by internal exposure may be regulated by lower expressions of bcl-2mRNA and bcl-2, lower bcl-2/bax value

  2. The effect of fractionated irradiation on cell kinetics

    International Nuclear Information System (INIS)

    Laasonen, A.; Pyrhoenen, S.; Kouri, M.; Raety, J.; Holsti, L.R.

    1991-01-01

    The effects of single and split-dose irradiation were compared by in vitro experiments on HeLa cells. Changes in rate of cell proliferation were detected by flow cytometry, simultaneously determining the DNA content and the bromodeoxyuridine incorporation of individual cells. Cell cultures were irradiated with either a single dose of 1-6 Gy or with a corresponding dose divided into multiple fractions given at 1-6-h intervals. A dose-dependent accumulation of cells in G2/M phase was observed. The method was sensitive enough for the detection of G2/M block even after 1 Gy. The block disappeared completely within a 24-h follow-up time at dose levels up to 3 Gy. Interestingly, no differences in cell kinetics were observed between the single and split-dose regiments. This approach proves to be valuable in evaluating novel fractionation models and the effects of radiation on the cell kinetics of human tumor cells. (orig.)

  3. DNA damage induced by radionuclide internal irradiation

    International Nuclear Information System (INIS)

    Cui Fengmei; Zhao Jingyong; Hong Chengjiao; Lao Qinhua; Wang Liuyi; Yang Shuqin

    2004-01-01

    Objective: To study the DNA damage of peripheral blood mononuclear cell (PBMC) in rats exposed to radionuclide internal irradiation. Methods: The radionuclides were injected into the rats and single cell get electrophoresis (SCGE) was performed to detect the length of DNA migration in the rat PBMC. Results: DNA migration in the rat PBMC increased with accumulative dose or dose-rate. It showed good relationship of dose vs. response and of dose-rate vs. response, both relationship could be described as linear models. Conclusion: Radionuclide internal irradiation could cause DNA damage in rat PBMC. (authors)

  4. Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

    International Nuclear Information System (INIS)

    Turesson, I.

    1990-01-01

    The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

  5. Effects of low-dose fractionated external irradiation on metabolic and structural characteristics of rat thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Nadolnik, L.; Niatsetskaya, Z. [Institute of Biochemistry, National Academy of Sciences of Belarus, Grodno (Belarus)

    2006-07-01

    Full text of publication follows: The problem of thyroid radiosensitivity to the effect of low dose external ionizing irradiation presently seems to be the least studied, and the experimental findings - the most contradictory. The aim of the work was to study the effects of long-term low-dose fractionated irradiation on the iodide metabolism and structure of the thyroid. Female Wistar rats weighing 140-160 g were irradiated 20 times (5 times a week, for 4 weeks) using a 60 Co installation. The single absorbed doses were 0.1, 0.25 and 0.5 Gy and the total ones - 2.0, 5.0 and 10.0 Gy, respectively. The animals were decapitated after 1 day, 4 and 24 weeks following the last irradiation. The thyroid tissue was used to assay for thyro-peroxidase (T.P.O.) activity as well as total, protein -bound and free iodide concentrations. Microscopic and morphometric examination of histologic thyroid preparations was carried out. Blood was assayed for thyroxin (T4) and triiodothyronine (T3) concentrations. After a day following the irradiation, the thyroid showed a pronounced increase in the concentration of total iodide (30.0-54.4%) as well in that of free (32.1-60.8%) and protein-bound ones (24.4-37.4%). The most pronounced iodide concentration elevation was noted in the 0.1 -Gy animals, with thyroid T.P.O. activity being raised by 48.0%. Only the 0.5 Gy-group had 1.4-1.5-fold reduced thyroid hormone levels. Four weeks after the irradiation, studied parameters of irradiated rats were brought back to the control values, except for the 0.5 Gy-group. However, after 24-weeks, the 0.5-and 0.25- irradiated rats experienced a 12-20% thyroid weight elevation in comparison with the control. The thyroid of these animals demonstrated reduced contents of total and free iodide as well as T.P.O. activity by 24.5 and 34.8%. The 0.1 Gy-group had a 1.7-fold increased T.P.O. activity. The concentration of the thyroid hormones was maintained diminished only in the 0.5 Gy -irradiated group. However

  6. International standards and agreements in food irradiation

    International Nuclear Information System (INIS)

    Cetinkaya, N.

    2004-01-01

    Full text: The economies of both developed and developing countries have been effected by their exported food and agricultural products. Trading policies of food and agricultural products are governed by international agreement as well as national regulations. Trade in food and agricultural commodities may be affected by both principal Agreements within the overall World Trade Organization (WTO) Agreement, though neither specifically refers to irradiation or irradiated foods. The principal Agreements are the Technical Barriers to Trade (TBT) Agreement and the Sanitary and Phyto sanitary (SPS) Agreement. The SPS of the WTO requires governments to harmonize their sanitary and phyto sanitary measures on as wide basis as possible. Related standards, guidelines and recommendations of international standard setting bodies such as the Codex Alimentarius Commission (food safety); the International Plant Protection Convention (IPPC) (plant health and quarantine); and International Office of Epizootic (animal health and zoo noses) should be used in such a harmonization. International Standards for Phyto sanitary Measures (ISPM) no.18 was published under the IPPC by FAO (April 2003, Rome-Italy). ISPM standard provides technical guidance on the specific procedure for the application of ionizing radiation as a phyto sanitary treatment for regulated pests or articles. Moreover, Codex Alimentarius Commission, Codex General Standard for Irradiated Foods (Stand 106-1983) and Recommended International Code of Practice were first published in 1983 and revised in March 2003. Scope of this standard applies to foods processed by ionizing radiation that is used in conjunction with applicable hygienic codes, food standards and transportation codes. It does not apply to foods exposed to doses imparted by measuring instruments used for inspection purposes. Codex documents on Principles and Guidelines for the Import/Export Inspection and Certification of Foods have been prepared to guide

  7. International standards and agreements in food irradiation

    International Nuclear Information System (INIS)

    Cetinkaya, N.

    2004-01-01

    The economies of both developed and developing countries have been effected by their exported food and agricultural products. Trading policies of food and agricultural products are governed by international agreement as well as national regulations. Trade in food and agricultural commodities may be affected by both principal Agreements within the overall World Trade Organization (WTO) Agreement, though neither specifically refers to irradiation or irradiated foods. The principal Agreements are the Technical Barriers to Trade (TBT) Agreement and the Sanitary and Phyto sanitary (SPS) Agreement. The SPS of the WTO requires governments to harmonize their sanitary and phyto sanitary measures on as wide basis as possible. Related standards, guidelines and recommendations of international standard setting bodies such as the Codex Alimentarius Commission (food safety); the International Plant Protection Convention (IPPC) (plant health and quarantine); and International Office of Epizootic (animal health and zoo noses) should be used in such a harmonization. International Standards for Phyto sanitary Measures (ISPM) no.18 was published under the IPPC by FAO (April 2003, Rome-Italy). ISPM standard provides technical guidance on the specific procedure for the application of ionizing radiation as a phyto sanitary treatment for regulated pests or articles. Moreover, Codex Alimentarius Commission, Codex General Standard for Irradiated Foods (Stand 106-1983) and Recommended International Code of Practice were first published in 1983 and revised in March 2003. Scope of this standard applies to foods processed by ionizing radiation that is used in conjunction with applicable hygienic codes, food standards and transportation codes. It does not apply to foods exposed to doses imparted by measuring instruments used for inspection purposes. Codex documents on Principles and Guidelines for the Import/Export Inspection and Certification of Foods have been prepared to guide international

  8. New pallet irradiation for Gammaster International

    Science.gov (United States)

    Möhlmann, Mr. J. H. F.

    1993-07-01

    State of the art technology offers many opportunities to improve production process with ionizing radiation. Also the requirements to this process become more and more stringent; who was aware of the ISO-9000 Standards? Now it is a necessary concept? Internal and external audits, in particular by Regulatory Bodies such as the FDA and DHSS/MCA, are necessary and commonplace requirements when operating in the Healthcare and Pharmaceutical sectors. Efficiency is a major requirement for industry and also for our radiation business. With all the above mentioned items in mind, Gammaster International B.V. in close cooperation with Nordion International Inc. has developed and built a new type Pallet Irradiator. In this new concept, our 22 years experience in gamma processing and the expertise gained in 10 years of operation of pallet irradiators was incorporated. For this irradiator Gammaster International designed and built a new process control console, incorporating state of the art technology such as: - A well-balanced safety system - A control panel, with status indication for all essential operating and safety parameters - Advances warning for necessary maintenance work - Automatic timer-setting control in addition to an automatic timer setting modification - Clear indication of the position of the product inside the unit and its status - Fully automatic product information generated when the product leaves the irradiation unit - Visual process control with the help of a color monitor - Incremental dose-control - Fault identification

  9. Fraction of a dose absorbed estimation for structurally diverse low solubility compounds.

    Science.gov (United States)

    Sugano, Kiyohiko

    2011-02-28

    The purpose of the present study was to investigate the prediction accuracy of the fully mechanistic gastrointestinal unified theoretical (GUT) framework for in vivo oral absorption of low solubility drugs. Solubility in biorelevant media, molecular weight, logP(oct), pK(a), Caco-2 permeability, dose and particle size were used as the input parameters. To neglect the effect of the low stomach pH on dissolution of a drug, the fraction of a dose absorbed (Fa%) of undissociable and free acids were used. In addition, Fa% of free base drugs with the high pH stomach was also included to increase the number of model drugs. In total twenty nine structurally diverse compounds were used as the model drugs. Fa% data at several doses and particle sizes in humans and dogs were collated from the literature (total 110 Fa% data). In approximately 80% cases, the prediction error was within 2 fold, suggesting that the GUT framework has practical predictability for drug discovery, but not for drug development. The GUT framework appropriately captured the dose and particle size dependency of Fa% as the particle drifting effect was taken into account. It should be noted that the present validation results cannot be applied for salt form cases and other special formulations such as solid dispersions and emulsion formulations. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. 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)

  11. Combined effect of external and internal irradiation

    International Nuclear Information System (INIS)

    Kiradzhiev, G.

    1987-01-01

    Some of the general regularities of the combined effect of external irradiation and iodine 131 are discussed. Data are adduced showing that modification of the effects of these two radiation factors, when jointly applied, is also determined by the quantitative relations of the applied doses of external and internal irradiation, referred to a particular moment of the effects. It was shown that the effects of the radionuclides in these combined radiation injuries are basically realized by two mechanisms: 1. changes are found in the radionuclide kinetic parameters (nonspecific effects); 2. changes in their kinetic parameters are absent (specific effect). These two mechanisms underlie different approaches to therapy

  12. Postirradiation examination of JOYO MK-II control rod (CRM601). Irradiation performance of shroud type absorber pin

    International Nuclear Information System (INIS)

    Tanaka, Kosuke; Kikuchi, Shin; Katsuyama, Kozo; Nagamine, Tsuyoshi; Mitsugi, Takeshi; Uto, Manabu; Tatebe, Kazuaki; Onose, Shoji; Maruyama, Tadashi

    1998-10-01

    This paper describes the results of postirradiation examination and analysis by CORAL code for irradiation performance of CRM601 control rod, which was the 6th reloaded control rod with shroud type absorber pins for use in JOYO MK-II core. The detailed visual examination indicated that there was no cladding breach in absorber pins. However, sodium ingress from the vent tube was observed in four absorber pins among seven pins. While a remarkable oval deformation occurred in cladding tube of helium bonded absorber pins, a little or no diametral change was observed in the absorber pins in which sodium ingress took place. From metallurgical observations and the analysis by CORAL code, it was estimated that the shroud tube installed in helium bonded absorber pins were irradiated at 720degC, and those in sodium bonded absorber pins were irradiated at 420degC. It was confirmed that diametral change of cladding depended on the initial gap between shroud and cladding tube. The results of present investigation indicate that it is desirable to use the materials with low thermal expansion coefficient for shroud tubes, and that sodium bonded absorber pins were advantageous for obtaining long life control rods. (author)

  13. Relationship between α/β and radiosensitivity and biologic effect of fractional irradiation of tumor cells

    International Nuclear Information System (INIS)

    Guo Chuanling; Chinese Academy of Sciences, Beijing; Wang Jufang; Jin Xiaodong; Li Wenjian

    2006-01-01

    Five kinds of malignant human tumor cells, i.e. SMMC-7721, HeLa, A549, HT29 and PC3 cell lines, were irradiated by 60 Co γ-rays to 1-6 Gy in a single irradiation or two irradiations of half dose. The radiosensitivity was compared with the dose-survival curves and D 50 and D 10 values. Differences in the D 50 and D 10 between the single and fractional irradiation groups showed the effect of fractional irradiation. Except for PC3 cells, all the cell lines showed obvious relationship between radiosensitivity and biologic effect of fractional irradiation and the α/β value. A cell line with bigger α/β was more radiation sensitive, with less obvious effect of fractional irradiation. The results indicate that there were obvious differences in radiosensitivity, repair ability and biologic effect of fractional irradiation between tumor cells from different tissues. To some tumor cell lines, the relationship between radiosensitivity, biologic effect of fractional irradiation and repair ability was attested. The α/β value of single irradiation can be regarded as a parameter to investigate the radiosensitivity and biologic effect of fractional irradiation of tumor cells. (authors)

  14. The relationship between survival and mutagenesis in Escherichia coli after fractionated ultraviolet irradiation

    International Nuclear Information System (INIS)

    Dzidic, S.; Salaj-Smic, E.; Trgovcevic, Z.

    1986-01-01

    The relationship between survival and mutagenesis in Escherichia coli after fractionated ultraviolet (UV) irradiation was studied. The cells were incubated either in buffer or nutrient media. Regardless of incubation conditions, greater survival is observed after fractionated irradiation than after acute irradiation. When the cells are incubated in buffer, UV mutagenesis decreases with an increase in the number of dose fractions. However, when the cells are cultivated in nutrient media, the increased survival is coupled with the enhanced capacity for UV mutagenesis. The authors, therefore, assume that during incubation in nutrient media, fractionated irradiation leads to full and prolonged expression of all UV inducible (SOS) genes, including those required for mutagenesis. (Auth.)

  15. Side branch absorber for exhaust manifold of two-stroke internal combustion engine

    Science.gov (United States)

    Harris, Ralph E [San Antonio, TX; Broerman, III, Eugene L.; Bourn, Gary D [Laramie, WY

    2011-01-11

    A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

  16. Food Irradiation. Proceedings of the International Symposium on Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-11-15

    For some years research has been done in several countries, with the object of contributing to the world's food supplies, on the application of nuclear methods to food preservation and processing. The importance of food preservation is of particular relevance in certain regions of the world where up to thirty per cent of harvested foodstuffs are being lost because of damage by animal pests and microorganisms. A series of international meetings have been held on this subject; the first, held in 1958 at Harwell, was followed by further meetings in 1960 in Paris and in 1961 in Brussels. The International Symposium on Food Irradiation organized by the International Atomic Energy Agency and the Food and Agriculture Organization of the United Nations through their Joint Division of Atomic Energy in Agriculture, and held at the Karlsruhe Nuclear Research Centre, Karlsruhe, from 6 to 10 June 1966, at the generous invitation of the Government of the Federal Republic of Germany, is the most recent of this series of meetings. It was held for the purpose of exchanging the most up-to-date results of research, of contributing towards co-operative efforts between Member States, and of stimulating trade in the international exchange of irradiated products between nations. Papers describing research over the past fourteen years were given by outstanding authorities; the results point to a breakthrough having been achieved in the use of ionizing radiation in food preservation, notwithstanding some problems still to be solved, such as overcoming changes in colour, flavour, odour or texture. The Symposium was attended by over 200 scientists from 25 countries and four international organizations. Sixty-nine papers were presented. It was shown that a wide variety of foodstuffs exist for which radiation could be used for three different purposes: to produce indefinitely stable products, to rid food of organisms that constitute health hazards, and to extend the normal shelf or market life

  17. Food Irradiation. Proceedings of the International Symposium on Food Irradiation

    International Nuclear Information System (INIS)

    1966-01-01

    For some years research has been done in several countries, with the object of contributing to the world's food supplies, on the application of nuclear methods to food preservation and processing. The importance of food preservation is of particular relevance in certain regions of the world where up to thirty per cent of harvested foodstuffs are being lost because of damage by animal pests and microorganisms. A series of international meetings have been held on this subject; the first, held in 1958 at Harwell, was followed by further meetings in 1960 in Paris and in 1961 in Brussels. The International Symposium on Food Irradiation organized by the International Atomic Energy Agency and the Food and Agriculture Organization of the United Nations through their Joint Division of Atomic Energy in Agriculture, and held at the Karlsruhe Nuclear Research Centre, Karlsruhe, from 6 to 10 June 1966, at the generous invitation of the Government of the Federal Republic of Germany, is the most recent of this series of meetings. It was held for the purpose of exchanging the most up-to-date results of research, of contributing towards co-operative efforts between Member States, and of stimulating trade in the international exchange of irradiated products between nations. Papers describing research over the past fourteen years were given by outstanding authorities; the results point to a breakthrough having been achieved in the use of ionizing radiation in food preservation, notwithstanding some problems still to be solved, such as overcoming changes in colour, flavour, odour or texture. The Symposium was attended by over 200 scientists from 25 countries and four international organizations. Sixty-nine papers were presented. It was shown that a wide variety of foodstuffs exist for which radiation could be used for three different purposes: to produce indefinitely stable products, to rid food of organisms that constitute health hazards, and to extend the normal shelf or market life

  18. Proton and photon absorbed-dose conversion coefficients for embryo and foetus from top-down irradiation geometry

    International Nuclear Information System (INIS)

    Chen, J.

    2007-01-01

    Absorbed-dose conversion coefficients are calculated for the embryo of 8 weeks and the foetus of 3, 6 or 9 months when the mother's body is exposed to protons and photons from top-down (TOP) direction. It provides data sets in addition to other standard irradiation geometries published previously. The TOP-irradiation geometry is considered here, because high-energy particles are often peaked from the TOP direction onboard aircraft. The results show that absorbed-doses from high-energy particles could be underestimated significantly if isotropic (ISO) irradiation geometry is assumed. For protons of 100 GeV, absorbed-doses from TOP irradiation are ∼2.3-2.9 times higher than the doses from ISO irradiation for different foetal ages. For 10 GeV photons, foetal doses from TOP irradiation are ∼6.8-12 times higher than the doses from ISO irradiation. The coefficients from TOP-irradiation geometry are given in wide energy ranges, from 100 MeV to 100 GeV for protons and from 50 V to 10 GeV for photons. They can, therefore, be used in various applications whenever exposure from the TOP-irradiation direction is concerned. (authors)

  19. Development of fluorescent, oscillometric and photometric methods to determine absorbed dose in irradiated fruits and nuts

    International Nuclear Information System (INIS)

    Kovacs, A.; Foeldiak, G.; Hargittai, P.; Miller, S.D.

    2001-01-01

    To ensure suitable quality control at food irradiation technologies and for quarantine authorities, simple routine dosimetry methods are needed for absorbed dose control. Taking into account the requirements at quarantine locations these methods would require nondestructive analysis for repeated measurements. Different dosimetry systems with different analytical evaluation methods have been tested and/or developed for absorbed dose measurements in the dose range of 0.1-10 kGy. In order to use the well accepted ethanolmonochlorobenzene dosimeter solution and the recently developed aqueous alanine solution in small volume sealed vials, a new portable, digital, and programmable oscillometric reader was developed. To make use of the availability of the very sensitive fluorimetric evaluation method, liquid and solid inorganic and organic dosimetry systems were developed for dose control using a new routine, portable, and computer controlled fluorimeter. Absorption or transmission photometric methods were also applied for dose measurements of solid or liquid phase dosimeter systems containing radiochromic dye agents, which change colour upon irradiation. (author)

  20. Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

    International Nuclear Information System (INIS)

    Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

    1993-01-01

    The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

  1. Fractionated total body irradiation; the gastrointestinal toxicity versus the conditioning effect for bone marrow transplantation with different fractionation schedules

    International Nuclear Information System (INIS)

    Walma, E.P.; Klapwijk, W.M.; Miller, A.M.

    1982-01-01

    In most cases, bone marrow transplantation is preceded by a conditioning regimen employing irradiation and/or cytotoxic drugs. The authors are searching for better fractionation schedules in order to optimize the conditioning regimen prior to transplantation of stem-cell-enriched bone marrow. They have determined damage to the gastrointestinal tract in dogs and mice after total body irradiation in mice and dogs following a number of fractionation schedules, and these results are presented. The schedules were chosen such as to minimize the interval between irradiation and the bone marrow transplantation and to maximize clinical feasibility. (Auth./C.F.)

  2. Thermodynamic pathways to melting, ablation, and solidification in absorbing solids under pulsed laser irradiation

    International Nuclear Information System (INIS)

    Lorazo, Patrick; Lewis, Laurent J.; Meunier, Michel

    2006-01-01

    The thermodynamic pathways involved in laser irradiation of absorbing solids are investigated in silicon for pulse durations of 500 fs and 100 ps. This is achieved by accounting for carrier and atom dynamics within a combined Monte Carlo and molecular-dynamics scheme and simultaneously tracking the time evolution of the irradiated material in ρ-T-P space. Our simulations reveal thermal changes in long-range order and state of aggregation driven, in most cases, by nonequilibrium states of rapidly heated or promptly cooled matter. Under femtosecond irradiation near the ablation threshold, the system is originally pulled to a near-critical state following rapid ( -12 s) disordering of the mechanically unstable crystal and isochoric heating of the resulting metallic liquid. The latter is then adiabatically cooled to the liquid-vapor regime where phase explosion of the subcritical, superheated melt is initiated by a direct conversion of translational, mechanical energy into surface energy on a ∼10 -12 -10 -11 s time scale. At higher fluences, matter removal involves, instead, the fragmentation of an initially homogeneous fluid subjected to large strain rates upon rapid, supercritical expansion in vacuum. Under picosecond irradiation, homogeneous and, at later times, heterogeneous melting of the superheated solid are followed by nonisochoric heating of the molten metal. In this case, the subcritical liquid material is subsequently cooled onto the binodal by thermal conduction and explosive boiling does not take place; as a result, ablation is associated with a ''trivial'' fragmentation process, i.e., the relatively slow expansion and dissociation into liquid droplets of supercritical matter near thermodynamic equilibrium. This implies a liquid-vapor equilibration time of ∼10 -11 -10 -10 s and heating along the binodal under nanosecond irradiation. Solidification of the nonablated, supercooled molten material is eventually observed on a ∼10 -11 -10 -9 s time scale

  3. Radiobiological effect of different irradiation fractionated regimens in human brain glioma

    International Nuclear Information System (INIS)

    Gai Xue; Yang Weizhi; Gao Li; Jiang Heng; Wang Mianrong; Shi Huizhen

    2010-01-01

    Objective: To evaluate the radiobiological effect of different irradiation fractionated regimens in human glioma cells (BT 325 cell line). Methods: The xenografts in Balb/c-nude mice were irradiated with different single and fractionated regimens. The single fraction dose was 10, 20, 30, 40 and 60 Gy, respectively. The fractionated regimens were 2 Gy x 5 fractions ( irradiated every day), and 3 Gy x 3 fractions (irradiated every other day), 3 Gy x 5 fractions (irradiated every day) and 4 Gy x 3 fractions (irradiated every other day), with total doses of 125 Gy, 114 Gy, 126 Gy and 112 Gy, respectively. The growth curve was used to evaluate the tumor doubling time. clonogenic assays was performed to draw the cell survival curve and analyze the radiobiological parameters with doses of 1, 2, 4, 6, 8 and 10 Gy. T 1/2 was measured by comet assay. Results: Tumor regression were not observed by single fraction irradiation, 2 Gy x 5 fractions and 3 Gy x 3 fractions irradiation regimens. The tumor regress was more significant with the increas of fraction dose. The 4 Gy x 3 fractions inhibited tumor more though not curing tumor. The cell doubling time of the BT 325 cell was 30. 16 h and the tumor doubling time of the xenograft was 43 days.When fitted with L-Q model, α was 0. 36 Gy -1 and β was 0. 057 Gy -2 . When fitted with the single-hit multi target model, D 0 was 1. 394 Gy, Dq was 2. 127 Gy and SF 2 was 0.714, respectively. The T 1/2 was 9.999 min. Conclusions: Glioma is a radioresistant tumor. Increase of the fraction dose improves recent effect.Further study is needed to control the tumor stem cells. (authors)

  4. The influence of fractionation on cell survival and premature differentiation after carbon ion irradiation

    International Nuclear Information System (INIS)

    Wang Jufang; Li Renming; Guo Chuanling; Fournier, C.; K-Weyrather, W.

    2008-01-01

    To investigate the influence of fractionation on cell survival and radiation induced premature differentiation as markers for early and late effects after X-rays and carbon irradiation. Normal human fibroblasts NHDF, AG1522B and WI-38 were irradiated with 250 kV X-rays, or 266 MeV/u, 195 MeV/u and 11 MeV/u carbon ions. Cytotoxicity was measured by a clonogenic survival assay or by determination of the differentiation pattern. Experiments with high-energy carbon ions show that fractionation induced repair effects are similar to photon irradiation. The relative biological effective (RBE) 10 values for clonogenic survival are 1.3 and 1.6 for irradiation in one or two fractions for NHDF cells and around 1.2 for AG1522B cells regardless of the fractionation scheme. The RBE for a doubling of post mitotic fibroblasts (PMF) in the population is 1 for both single and two fractionated irradiation of NHDF cells. Using 11 MeV/u carbon ions, no repair effect can be seen in WI-38 cells. The RBE 10 for clonogenic survival is 3.2 for single irradiation and 4.9 for two fractionated irradiations. The RBE for a doubling of PMF is 3.1 and 5.0 for single and two fractionated irradiations, respectively. For both cell lines the effects of high-energy carbon ions representing the irradiation of the skin and the normal tissue in the entrance channel are similar to the effects of X-rays. The fractionation effects are maintained. For the lower energy, which is representative for the irradiation of the tumor region, RBE is enhanced for clonogenic survival as well as for premature terminal differentiation. Fractionation effects are not detectable. Consequently, the therapeutic ratio is significantly enhanced by fractionated irradiation with carbon ions. (author)

  5. A simple graphical method for deriving kinetics of repair from fractionated and protracted irradiations

    International Nuclear Information System (INIS)

    Scalliet, P.; Schueren, E. van der; Erfmann, R.K.L.; Landuyt, W.

    1988-01-01

    The authors present a method for the derivation of the time constant of repair from fractionated and protracted irradiations, using formulae based on those derived by Dale (1985) and Liversage (1969) establishing the correlation between the biological effects of low dose rate and acute fractionated irradiation. (UK)

  6. Understanding and predicting the behaviour of silver base neutron absorbers under irradiations

    International Nuclear Information System (INIS)

    Desgranges, C.

    1998-01-01

    The effect of neutron irradiation induced transmutations on the swelling of AgInCd (AIC) alloys used as neutron absorber in the control rods of Pressurized Water Reactors has been studied both experimentally and theoretically. Effective atomic volumes have been determined in synthetic AgCdInSn alloys with various compositions and containing fcc and hc phases, representative of irradiated AIC (Sn is a transmutation product). Swelling is shown to result first from the transmutation of Ag into Cd and of In into Sn, both with larger effective volume than the mother atom, and second from grain boundaries precipitation of s still less dense hc phase when solid solubility of transmuted products is exceeded. For both fcc and hc phases, we have determined profiles at the temperatures in the vicinity of the operating temperature. Unusual characteristics of second phase growth at grain boundaries induced by transmutations are identified on a simple binary alloy model: kinetics is controlled by irradiation temperature which scales diffusivities and flux which scales transmutation rates, as well as by the grain size in the underlying matrix. To address the AgInCdSn alloys, a novel technique is proposed to model diffusion in multicomponent alloys. It is based on a linearization of a simple atomistic model. With a single set of parameters, for each phase, our model well reproduces our interdiffusion measurements in quaternary alloys as well as existing interdiffusion experiments in binary alloys. Finally this diffusion model implemented with a moving interface algorithm is used to model the growth of the second phase induced by transmutation in the AIC under irradiation. (authors)

  7. Recovery from sublethal damage during fractionated irradiation of human FaDu SCC

    International Nuclear Information System (INIS)

    Petersen, Cordula; Zips, Daniel; Krause, Mechthild; Voelkel, Wolfram; Thames, Howard D.; Baumann, Michael

    2005-01-01

    Background and purpose: The present study addresses whether recovery of sublethal damage in tumours may change during fractionated irradiation in FaDu human squamous cell carcinoma and whether such an effect might contribute to the pronounced time factor of fractionated irradiation previously found in this tumour. Patients and methods: FaDu tumours were transplanted s.c. into the right hind leg of NMRI nu/nu mice. Single doses or 2, 4, and 8 equal fractions in 3.5 days were applied in previously unirradiated tumours and after priming with 18 fractions of 3 Gy in 18 or 36 days. All irradiations were given under clamp hypoxic conditions. Experimental endpoints were tumour control dose 50% (TCD 50 ) and α/β values without and after priming. Results: Without priming TCD 50 increased with increasing number of fractions from 38.8 Gy (95% CI 35;45) after single dose irradiation to 54.0 Gy (42;57) after 8 fractions. No increase in TCD 50 when given in 1, 2, 4, or 8 fractions in 3.5 days was found after priming with 18 3-Gy fractions in 18 and 36 days. After priming with 18 fractions in 18 days TCD 50 remained constant at 25 Gy and after priming with 18 fractions in 36 days at 42 Gy. The α/β ratio without priming was 68 Gy (42;127). After fractionated irradiation with 18 3-Gy fractions in 18 and 36 days the α/β ratio increased to 317 Gy (38;∞) and to infinite, respectively. Conclusions: Our results indicate that clonogenic cells in FaDu tumours lose entirely their capacity to recover from sublethal radiation damage during fractionated irradiation. Therefore, an increased repair capacity as an explanation for the pronounced time factor of fractionated irradiation in this tumour can be ruled out

  8. Measurement of absorbed radiation doses during whole body irradiation for bone marrow transplants using thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Giordani, Adelmo Jose; Segreto, Helena Cristina Comodo; Segreto, Roberto Araujo; Medeiros, Regina Bitelli; Oliveira, Jose Salvador R. de

    2004-01-01

    The objective was to evaluate the precision of the absorbed radiation doses in bone marrow transplant therapy during whole body irradiation. Two-hundred CaSO 4 :Dy + teflon tablets were calibrated in air and in 'phantom'. These tablets were randomly selected and divided in groups of five in the patients' body. The dosimetric readings were obtained using a Harshaw 4000A reader. Nine patients had their entire bodies irradiated in parallel and opposite laterals in a cobalt-60 Alcion II model, with a dose rate of 0.80 Gy/min at 80.5 cm, {(10 ? 10) cm 2 field. The dosimetry of this unit was performed using a Victoreen 500 dosimeter. For the determination of the mean dose at each point evaluated, the individual values of the tablets calibrated in air or 'phantom' were used, resulting in a build up of 2 mm to superficialize the dose at a distance of 300 cm. In 70% of the patients a variation of less than 5% in the dose was obtained. In 30% of the patients this variation was less than 10%, when values obtained were compared to the values calculated at each point. A mean absorption of 14% was seen in the head, and an increase of 2% of the administered dose was seen in the lungs. In patients with latero-lateral distance greater than 35 cm the variation between the calculated doses and the measured doses reached 30% of the desired dose, without the use of compensation filters. The measured values of the absorbed doses at the various anatomic points compared to the desired doses (theoretic) presented a tolerance of ± 10%, considering the existent anatomical differences and when using the individual calibration factors of the tablets. (author)

  9. Allograft tolerance in pigs after fractionated lymphoid irradiation. I. Skin grafts after partial lateral irradiation and bone marrow cell grafting

    International Nuclear Information System (INIS)

    Vaiman, M.; Daburon, F.; Remy, J.; Villiers, P.A.; de Riberolles, C.; Lecompte, Y.; Mahouy, G.; Fradelizi, D.

    1981-01-01

    Experiments with pigs have been performed to establish bone marrow chimerism and skin graft tolerance between SLA genotyped animals. Recipients were conditioned by means of fractionated partial irradiation from lateral cobalt sources (partial lateral irradiation (PLI)). The head, neck, and lungs were protected with lead, the rest of the body being irradiated including the thymus, the majority of lymphoid organs with spleen, and most of the bone marrow sites

  10. Functional activity of symphathetic-adrenal system under chronic and fractionated irradiation of rats

    International Nuclear Information System (INIS)

    Musagalieva, G.M.

    1975-01-01

    Chronic irradiation of rats at 5 R twice a week (total dose 400 R) significantly increased adrenaline concentration in the brain, liver and kidney and dophamine and DOPA concentration in liver tissue, adrenal glands and thymus. Fractionated irradiation (chronic irradiation at 400 R plus acute single irradiation at 400 R) increased the adrenaline level in the brain and heart muscle and led to a higher concentration of dophamine and DOPA in the liver, thymus and heart muscle [ru

  11. [Internal fixation treatment of multiple rib fractures with absorbable rib-connecting-pins under epidural anesthesia].

    Science.gov (United States)

    Liu, Jinliang; Li, Keyao; Ju, Zhenlong; Bai, Yan

    2011-03-01

    To study the indications, methods and experience of absorbable rib-connecting-pins fixation in the treatment of multiple rib fractures. 52 cases with multiple rib fractures were performed internal fixation with absorbable rib-connecting-pins under epidural anesthesia. All cases were followed up for 1 to 12 months, with an average of 5 months. All fractures were achieved healing in 3 to 6 months after the operation and were not found chest wall deformity. Absorbable rib-connecting-pins fixation is a simple and effective method and worthies recommending to perform operation for the appropriate cases with multiple rib fractures.

  12. Fractionation of gamma-emitting fission products absorbed by red kidney beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    D'Souza, T.J.; Mistry, K.B.

    1980-01-01

    The gamma-emitting fission product nuclides 106 Ru, 125 Sb, 137 Cs and 144 Ce that accumulated in the edible pods of bean (Phaseolus vulgaris L.) plants grown in nutrient culture were subjected to chemical fractionation. The results indicated that the largest fraction of 106 Ru, 125 Sb and 144 Ce was associated with ionic forms including salts of organic acids, phosphates, carbonates and some protein-bound forms extracted with dilute mineral acids (acid fraction). The association of these radionuclides with lipids including lipophyllic pigments, free amino acids and amino sugars (ethanol fraction) was next in significance. The association of 137 Cs was, however, greater with the ethanol fraction than with the acid fraction. Considerably reduced amounts of the fission products were present in the pectates, proteins, polysaccharides and nucleic acids. (U.K.)

  13. Sulfur transfer in the distillate fractions of Arabian crude oils under gamma-irradiation

    Science.gov (United States)

    Basfar, Ahmed A.; Soliman, Yasser S.; Alkhuraiji, Turki S.

    2017-05-01

    Desulfurization of light distillation fractions including gasoline, kerosene and diesel obtained from the four Arabian crude oils (heavy, medium, light and extra light) upon γ-rays irradiation to different doses was investigated. In addition, yields vol%, FTIR analysis, kinematic viscosity and density of all distillation fractions of irradiated crude oils were evaluated. Limited radiation-induced desulfurization of those fractions was observed up to an irradiation dose of 200 kGy. FTIR analysis of those fractions indicates the absence of oxidized sulfur compounds, represented by S=O of sulfone group, indicating that γ-irradiation of the Arabian crude oils at normal conditions does not induce an oxidative desulfurization in those distillation fractions. Radiation-induced sulfur transfer decreases by 28.56% and increases in total sulfur by 16.8% in Arabian extra light oil and Arabian medium crude oil respectively.

  14. Optimum combinations of visible and near-infrared reflectances for estimating the fraction of photosynthetically available radiation absorbed by plants

    Science.gov (United States)

    Podaire, Alain; Deschamps, Pierre-Yves; Frouin, R.; Asrar, Ghassem

    1991-01-01

    A useful parameter to estimate terrestrial primary productivity, that can be sensed from space, is the daily averaged fraction of Photosynthetically Available Radiation (PAR) absorbed by plants. To evaluate this parameter, investigators have relied on the fact that the relative amount of radiation reflected by a vegetated surface in the visible and near infrared depends on the fraction of the surface covered by the vegetation and therefore, correlates with absorbed PAR. They have used vegetation indices, namely normalized difference and simple ratio, to derive absorbed PAR. The problem with normalized difference and simple ratio is first, they are non linear functions of radiance or reflectance and therefore, cannot be readily applied to heterogeneous targets, second, they are used in generally nonlinear relationships, which make time integrals of the indices not proportional to primary productivity, and third, the relationships depend strongly on the type of canopy and background. To remove these limitations, linear combinations of visible and near infrared reflectances at optimum (one or two) viewing zenith angles are proposed.

  15. Spatiotemporal Fractionation Schemes for Irradiating Large Cerebral Arteriovenous Malformations

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Bussière, Marc R. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Chapman, Paul H. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Loeffler, Jay S.; Shih, Helen A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-07-01

    Purpose: To optimally exploit fractionation effects in the context of radiosurgery treatments of large cerebral arteriovenous malformations (AVMs). In current practice, fractionated treatments divide the dose evenly into several fractions, which generally leads to low obliteration rates. In this work, we investigate the potential benefit of delivering distinct dose distributions in different fractions. Methods and Materials: Five patients with large cerebral AVMs were reviewed and replanned for intensity modulated arc therapy delivered with conventional photon beams. Treatment plans allowing for different dose distributions in all fractions were obtained by performing treatment plan optimization based on the cumulative biologically effective dose delivered at the end of treatment. Results: We show that distinct treatment plans can be designed for different fractions, such that high single-fraction doses are delivered to complementary parts of the AVM. All plans create a similar dose bath in the surrounding normal brain and thereby exploit the fractionation effect. This partial hypofractionation in the AVM along with fractionation in normal brain achieves a net improvement of the therapeutic ratio. We show that a biological dose reduction of approximately 10% in the healthy brain can be achieved compared with reference treatment schedules that deliver the same dose distribution in all fractions. Conclusions: Boosting complementary parts of the target volume in different fractions may provide a therapeutic advantage in fractionated radiosurgery treatments of large cerebral AVMs. The strategy allows for a mean dose reduction in normal brain that may be valuable for a patient population with an otherwise normal life expectancy.

  16. International standards, Agreements and Policy of food Irradiation

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1997-01-01

    There are few internationally recognised standards and agreements related to irradiated foods. Codex Alimentarius has its General standard for Irradiated foods. This sets standards for the production of irradiated foods that are safe and nutritionally adequate. Guidelines for the proper processing of foods by irradiation are covered in the Codex Recommended International Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Food. For irradiation as a quarantine treatment for fruit, vegetables and other plants, the relevant international organization is the International Plant Protection Convention (IPPC), IPPC has no standards or guidelines for irradiation treatments. However, regional organizations within IPPC are moving towards recognition of irradiation as a technically viable and effective method of insect disinfestation. Especially notable are actions within the North American Plant Protection Organisation (NAPPO). NAPPO has endorsed a standard on the use of irradiation as a quarantine treatment. Other speakers have provided considerable detail on the Codex standard and on the situation with regard to quarantine issues. In this talk I will concentrate on irradiated foods as commodities that will be traded internationally in increasing amounts as we approach the next century. International trade is governed by bilateral arrangements. However, these arrangements should be consistent with the overarching multilateral agreements of the World trade Organization (WTO). The WTO Agreements do not refer directly to irradiation or irradiated foods. However, in this talk I will try to interpret the implications of the Agreements for trade in irradiated food. (Author)

  17. International standards, Agreements and Policy of food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, P.B. [Industrial and Biological Section. Institute of Geological and Nuclear Science. P.O. Box 31. Lower Hutt (New Zealand)

    1997-12-31

    There are few internationally recognised standards and agreements related to irradiated foods. Codex Alimentarius has its General standard for Irradiated foods. This sets standards for the production of irradiated foods that are safe and nutritionally adequate. Guidelines for the proper processing of foods by irradiation are covered in the Codex Recommended International Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Food. For irradiation as a quarantine treatment for fruit, vegetables and other plants, the relevant international organization is the International Plant Protection Convention (IPPC), IPPC has no standards or guidelines for irradiation treatments. However, regional organizations within IPPC are moving towards recognition of irradiation as a technically viable and effective method of insect disinfestation. Especially notable are actions within the North American Plant Protection Organisation (NAPPO). NAPPO has endorsed a standard on the use of irradiation as a quarantine treatment. Other speakers have provided considerable detail on the Codex standard and on the situation with regard to quarantine issues. In this talk I will concentrate on irradiated foods as commodities that will be traded internationally in increasing amounts as we approach the next century. International trade is governed by bilateral arrangements. However, these arrangements should be consistent with the overarching multilateral agreements of the World trade Organization (WTO). The WTO Agreements do not refer directly to irradiation or irradiated foods. However, in this talk I will try to interpret the implications of the Agreements for trade in irradiated food. (Author)

  18. Colon mucosal cells after high-dose fractional irradiation

    International Nuclear Information System (INIS)

    Zorc-Pleskovic, R.; Vraspir-Porenta, O.; Petrovic, D.; Zorc, M.; Pleskovic, L.

    2000-01-01

    The aim of this study was to investigate histological and stereological changes in cryptal enterocytes, mucosal lymphocytes and mast cells 10 days after irradiation. For experimental model, 24 Beagle dogs 1-2 years old were used. Twelve dogs were irradiated 20 days with 32 Gy over the whole pelvis and tail. Another 12 dogs represented a control group. For the detection of apoptosis, the TUNEL technique was used. Histological and stereological analyses were performed using a Wild sampling microscope M 1000. In the irradiated group, volume density (P < 0.01), numerical density (P < 0.05) and average volume of lymphocytes (P < 0.001) were significantly lower than in the nonirradiated group. Numerical areal density of mast cells in the irradiated group was also significantly lower (P < 0.05). Volume density (P < 0.001) and average volume of mast cells (P < 0.001) were significantly higher in the irradiated group. The results of our experiments show that irradiation causes injury and loss of lymphocytes and mast cells in the colon mucosa. Apoptosis was detected in enterocytes and lymphocytes in the irradiated group and in nonirradiated group in equal numbers (2.5 ± 0.3 vs. 2.3 ± 0.3; ns.), suggesting that 10 days after high-dose irradiation, the cell loss is not due to apoptosis. (author)

  19. Chromosome aberrations in human peripheral lymphocytes induced by single or fractionated X-irradiation

    International Nuclear Information System (INIS)

    Ivanov, B.; Leonard, A.; Deknyudt, G.

    1980-01-01

    Investigated is the effect of single (125 and 250 R) and fractionated (2x125 R) irradiation on the output of chromosome aberrations in lymphocytes of human peripheral blood kept between irradiations at the temperature of 5 deg C. The single irradiation is carried out immediately after vein-puncture. In the case of fractionated irradiation the first dose of 125R is given after vein-puncture, the second, in the interval of 2, 8 and 24 hours. Blood is cultivated immediately after two irradiations in order to prepare metaphase plates for cytogenic analysis. Repair processes in cell heritage structures are not realised in blood irradiated by fractions which is kept at 5 deg C between irradiations. On the contrary, chromosome fragments, interstitial deletions, aberrant cells and cell breaks are found in a large amount in blood irradiated by fractions. They have appeared with the authentically high statistic difference as compared with the cells irradiated one time with the same dose. This effect is probably attained due to blood preservation

  20. The kinetics of repair in mouse lung after fractionated irradiation

    International Nuclear Information System (INIS)

    Travis, E.L.; Thames, H.D.; Watkins, T.L.; Kiss, I.

    1987-01-01

    The kinetics of repair of sublethal damage in mouse lung was studied after fractionated doses of 137 Cs γ-rays. A wide range of doses per fraction (1.7-12 Gy) was given with interfraction intervals ranging from 0.5 to 24 h. Data were analysed by a direct method of analysis using the incomplete repair model. The half-time of repair (Tsub(1/2)) was 0.76 h for the pneumonitis phase of damage (up to 8 months) and 0.65 h for the later phase of damage up to 12 months. Rate of repair was dependent on fraction size for both phases of lung damage and was faster after large dose fractions than after small fractions. Tsub(1/2) was 0.6 h (95% c.1. 0.53, 0.69) for doses per fraction greater than 5 Gy and 0.83 h (95% c.1. 0.76, 0.92) for doses per fraction of 2 Gy. Repair was nearly complete by 6 h at least for the pneumonitis phase of damage. If extrapolated to humans, these results imply that treatments with multiple fractions per day involving the lung will not be limited by the necessity for interfraction intervals much longer than 6 h. (author)

  1. Development Manufacturing Method of Highly Functional Kapok Fiber Absorbent Using Irradiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jae Sung; Nho, Young Chang; Kang, Phil Hyun; Baek, Myung Hwa

    2006-01-01

    The hydrophobic characteristic of kapok fibers was changed to hydrophilic property after NaClO2, treatments which is able to break all phenolic units especially lignin. After NaClO2 treatment, NaIO4, applied to kapok fibers for opening hexagonal polysaccharide structure, this step led to produce carbonyl groups(>C=O) on kapok fibers. In the final step, NaClO2, treatments were performed again to provide carboxyl groups(-COOH) on kapok fibers. In addition, kapok fibers after all chemical treatments were retained hollow structure which was observed by scanning electron microscopy(SEM). Kapok fibers which were obtained after chemical treatments would be a good heavy metal absorbent when these fibers applied less than in 10 mg/L standard solution. Moreover, these fibers were not detached heavy metals even added physical forces and used kapok fibers are able to reuse after detached heavy metals under pH 2-3. The degree of grafting increased as the irradiation dose increased, and are in the range 32% to 250% when the concentration of glycidyl methacrylate monomer was 50 vol. %. Based on this result, various functional groups are possible to be attached on kapok fibers used by radiation grafting technique

  2. The proliferative response of mouse intestinal crypts during fractionated irradiation of carbon beams

    International Nuclear Information System (INIS)

    Abo, M.; Abe, Y.; Mariya, Y.; Ando, K.

    2000-01-01

    Clonogenic assay of jejunal crypt during carbon beam and X-ray irradiations was performed. Fractionation with top-up dose assay revealed carbon beam irradiations caused more damage than X-ray did. To clarify this problem is urgent. (author)

  3. Evaluation of cell regeneration of bone marrow after fractionated irradiation of mouse in toto

    International Nuclear Information System (INIS)

    Maisin, H.; Evercoren, A. van; Anckaert, M.A.; Coster, B.M. de

    1979-01-01

    We have studied the recovery for mice bone marrow cells after fractionated irradiation of the whole body. The additional dose (Dr) to obtain a given biological effect if the irradiation is split in two equal subfractions (2 Di) separated by a short interval of time (i) is 40 rad per day when the interval of time between the two irradiations is lenghtened of one day [fr

  4. Kantian fractionalization predicts the conflict propensity of the international system.

    Science.gov (United States)

    Cranmer, Skyler J; Menninga, Elizabeth J; Mucha, Peter J

    2015-09-22

    Network science has spurred a reexamination of relational phenomena in political science, including the study of international conflict. We introduce a new direction to the study of conflict by showing that the multiplex fractionalization of the international system along three key dimensions is a powerful predictor of the propensity for violent interstate conflict. Even after controlling for well-established conflict indicators, our new measure contributes more to model fit for interstate conflict than all of the previously established measures combined. Moreover, joint democracy plays little, if any, role in predicting system stability, thus challenging perhaps the major empirical finding of the international relations literature. Lastly, the temporal variability of our measure with conflict is consistent with a causal relationship. Our results have real-world policy implications as changes in our fractionalization measure substantially aid the prediction of conflict up to 10 years into the future, allowing it to serve as an early warning sign of international instability.

  5. Sulfur transfer in the distillate fractions of Arabian crude oils under gamma-irradiation

    International Nuclear Information System (INIS)

    Basfar, Ahmed A.; Soliman, Yasser S.; Alkhuraiji, Turki S.

    2017-01-01

    Desulfurization of light distillation fractions including gasoline, kerosene and diesel obtained from the four Arabian crude oils (heavy, medium, light and extra light) upon γ-rays irradiation to different doses was investigated. In addition, yields vol%, FTIR analysis, kinematic viscosity and density of all distillation fractions of irradiated crude oils were evaluated. Limited radiation-induced desulfurization of those fractions was observed up to an irradiation dose of 200 kGy. FTIR analysis of those fractions indicates the absence of oxidized sulfur compounds, represented by S=O of sulfone group, indicating that γ-irradiation of the Arabian crude oils at normal conditions does not induce an oxidative desulfurization in those distillation fractions. Radiation-induced sulfur transfer decreases by 28.56% and increases in total sulfur by 16.8% in Arabian extra light oil and Arabian medium crude oil respectively. - Highlights: • Limited desulfurization in the light distillate fraction of Arabian crude oils using γ-rays was observed. • FTIR analysis confirms limited unchanged in density, viscosity and yields of Arabian crude oils. • In absence of oxidizer, radiation-induced sulfur transfer was observed in gasoline and diesel fractions of Arabian crude oils. • Radiation-induced oxidative desulfuration of the light distillate fractions depends on its characteristics.

  6. Differential effects of fractionated X irradiation on mouse spermatogonial stem cells

    NARCIS (Netherlands)

    van der Meer, Y.; Huiskamp, R.; Davids, J. A.; de rooij, D. G.

    1993-01-01

    The response of spermatogonial stem cells to fractionated X irradiation was studied in the various stages of the spermatogenic cycle of the CBA mouse. Fractionated doses of 2 + 2, 1 + 3, and 3 + 1 Gy with a 24-h interval between the doses were compared with a single dose of 4 Gy. The numbers of

  7. Legal aspects and international implications of food irradiation

    International Nuclear Information System (INIS)

    Gerard, Alain.

    1977-11-01

    This paper reports on the status of work on food irradiation at international level, namely the IAEA/FAO/WHO Vienna recommendations, the proposed EEC directive, and the Codex alimentarius draft standards. It then deals with the legal aspects of the subject, in particular the problems concerning definitions, controls and instructions, and finally reviews the regulations for international trade in irradiated foodstuffs. (NEA) [fr

  8. Response of the skin of hamsters to fractionated irradiation with X rays or accelerated carbon ions

    International Nuclear Information System (INIS)

    Leith, J.T.; Powers-Risius, P.; Woodruff, K.H.; McDonald, M.; Howard, J.

    1981-01-01

    The ventral thoracic skin of hamsters was irradiated with either single, split (two fractions given in 24 hr), or multiple (five fractions given daily) exposures of X rays or accelerated carbon ions using a 4-cm spread Bragg peak. Animals were positioned in the heavy-ion beam so that the ventral thoracic skin surface was 1 cm distal to the proximal peak of the modified beam. Early skin reactions from 6 to 30 days postirradiation were assessed. Using the average skin reactions produced in this period, it was found that the relative biological effect (RBE) for single doses of carbon ions was about 1.6 (5-17 Gy per fraction), for two fractions about 1.8 (5-17 Gy perfraction), and for five fractions about 1.9 (2.4-7.2 Gy per fraction). The fractional amount of sublethal damage repaired after carbon ion irradiation was about 0.3 (at dose levels of 2.4-8.0 Gy per fraction) compared to a value of about 0.45 (at dose levels of 60-13.0 Gy per fraction) found for the fractionated X irradiations, indicting about a 33% decrease in the relative amount of sublethal damage repaired after carbon ion irradiation in this position in the spread Bragg curve. Also, data were interpreted using plots of the reciprocal total dose needed to produce a given level of skin damage versus the dose per fraction used in the multifraction experiments, and of the RBE versus dose per fraction obtained from a nonparametric analysis of the responses. These approaches allow estimation of RBE at dose levels relevant to the clinical situation. Also, estimation may be made of the maximum permissible RBE by using the zero dose intercept value from the linear reciprocal dose plot. With this approach, the RBE at a dose level of 2 Gy is about 2.5 and the maximum RBE value is about 2.7

  9. Tests of equal effect per fraction in microcolony assays of survival after fractionated irradiations

    International Nuclear Information System (INIS)

    Taylor, J.M.G.

    1985-01-01

    H.D Thames, Jr. and H.R. Withers propose a test of an equal effect per fraction in microcolony assays after fractionated radiation, in which the total effect is measured by counting microcolonies derived from surviving cells in a tissue. The factors considered to influence the cytocidal effect per fraction are incomplete repair, repopulation, and synchrony. The statistics used in the method are criticized and conditions are given under which the test should not be used. An alternative method of testing for an equal effect per fraction is proposed. The pros and cons of each test are discussed and compared using some mouse jejunal crypt cell survival data

  10. Influence of trichlorfon and fractionated irradiation on hydroproteolytic activity of pancreas and intestinal tissues of rats

    Energy Technology Data Exchange (ETDEWEB)

    Kocmierska-Grodzka, D [Akademia Medyczna, Bialystok (Poland). Zaklad Farmakologii

    1976-03-01

    Investigations were carried out of the hydroproteolytic activity of pancreas, small intestine and colon of rats after fractionated irradiation (5x150 R). Marked postirradiation enhancement of lipase activity was found in pancreas and duodenal part of intestine as well as an increase of B-glucuronidase and acid phosphatase activity in nearly all parts of the intestinal tissues. Fractionated irradiation resulted in an increase of pancreatic catheptic (proteolytic) activity, causing simultaneous decrease of proteolytic activity in intestine and colon. Preventive administation of Trichlorfon ten days before irradiation (10 mg or 30 mg/kg) evoked modification of hydroproteolytic activity in intestinal tissues of healthy and irradiated rats. 30mg/kg Trichlorfon exerted antilipolytic and anticatheptic effects in pancreas and intestinal tissues of irradiated rats.

  11. Accumulation of DNA Double-Strand Breaks in Normal Tissues After Fractionated Irradiation

    International Nuclear Information System (INIS)

    Ruebe, Claudia E.; Fricke, Andreas; Wendorf, Juliane; Stuetzel, Annika; Kuehne, Martin; Ong, Mei Fang; Lipp, Peter; Ruebe, Christian

    2010-01-01

    Purpose: There is increasing evidence that genetic factors regulating the recognition and/or repair of DNA double-strand breaks (DSBs) are responsible for differences in radiosensitivity among patients. Genetically defined DSB repair capacities are supposed to determine patients' individual susceptibility to develop adverse normal tissue reactions after radiotherapy. In a preclinical murine model, we analyzed the impact of different DSB repair capacities on the cumulative DNA damage in normal tissues during the course of fractionated irradiation. Material and Methods: Different strains of mice with defined genetic backgrounds (SCID -/- homozygous, ATM -/- homozygous, ATM +/- heterozygous, and ATM +/+ wild-type mice) were subjected to single (2 Gy) or fractionated irradiation (5 x 2 Gy). By enumerating γH2AX foci, the formation and rejoining of DSBs were analyzed in organs representative of both early-responding (small intestine) and late-responding tissues (lung, kidney, and heart). Results: In repair-deficient SCID -/- and ATM -/- homozygous mice, large proportions of radiation-induced DSBs remained unrepaired after each fraction, leading to the pronounced accumulation of residual DNA damage after fractionated irradiation, similarly visible in early- and late-responding tissues. The slight DSB repair impairment of ATM +/- heterozygous mice was not detectable after single-dose irradiation but resulted in a significant increase in unrepaired DSBs during the fractionated irradiation scheme. Conclusions: Radiation-induced DSBs accumulate similarly in acute- and late-responding tissues during fractionated irradiation, whereas the whole extent of residual DNA damage depends decisively on the underlying genetically defined DSB repair capacity. Moreover, our data indicate that even minor impairments in DSB repair lead to exceeding DNA damage accumulation during fractionated irradiation and thus may have a significant impact on normal tissue responses in clinical

  12. Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products

    International Nuclear Information System (INIS)

    Moriyama, Satoshi; Kurihara, Katsuhiko; Yokokawa, Nobuhiko; Satake, Masahiro; Juji, Takeo

    2001-01-01

    Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected. (author)

  13. Noninvasive photoacoustic measurement of absorption coefficient using internal light irradiation of cylindrical diffusing fiber

    Science.gov (United States)

    Peng, Dong-qing; Zhu, Li-li; Li, Zhi-fang; Li, Hui

    2017-09-01

    Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and internal light irradiation of cylindrical diffusing fiber (CDF) to quantify the target optical absorption coefficient. Absorption coefficients for ink absorbers are firstly determined through photoacoustic and spectrophotometric measurements at the same excitation, which demonstrates the feasibility of this method. Also, the optical absorption coefficients of ink absorbers with several concentrations are measured. Finally, the two-dimensional scanning photoacoustic image is obtained. Optical absorption coefficient measurement and simultaneous photoacoustic imaging of absorber non-invasively are the typical characteristics of the method. This method can play a significant role for non-invasive determination of blood oxygen saturation, the absorption-based imaging and therapy.

  14. Wholesomeness studies in the International Food Irradiation Project

    Energy Technology Data Exchange (ETDEWEB)

    Elias, P S [International Food Irradiation Project, Federal Research Centre for Nutrition

    1980-01-01

    Despite more than 25 years of history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and scientific investigations are required to provide reassurance as to the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subjects for the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans.

  15. Effect of absorbed dose and storage length on electron paramagnetic resonance (EPR) signal strength in irradiated alfalfa seeds

    International Nuclear Information System (INIS)

    Li Naining

    2006-01-01

    A kind of alfalfa seeds was irradiated by 1, 2, 3, 4 and 5 kGy at a dose rate of 6.288 kGy·h -1 in a self-shielded irradiator of 137 Cs gamma rays. The EPR spectra, which were measured subsequently between 0.3401 and 0.3501 T, showed that there was a direct proportional relationship between the EPR signal strength of free radicals produced by gamma irradiation in the alfalfa seeds and absorbed dose. The first derivative EPR spectra of the alfalfa seeds were very clear and easy to identify. However, the EPR signal strength of the peak-to-peak amplitude decreased rapidly and most of them decayed beyond 50% within 3 days after the seeds were irradiated. It tended to stabilize after half a month since the seeds were irradiated. the differences of the EPR signal strength between the irradiated and unirradiated alfalfa seeds still remained. All seeds were stored at ambient temperature for more than 3 months. Therefore, using EPR spectrometry technique to measure free radicals in alfalfa seeds as a means to determine whether the seeds have been irradiated or not is feasible, relatively fast and simple. (authors)

  16. Absorbant materials

    International Nuclear Information System (INIS)

    Quetier, Monique.

    1978-11-01

    Absorbants play a very important part in the nuclear industry. They serve for the control, shut-down and neutron shielding of reactors and increase the capacity of spent fuel storage pools and of special transport containers. This paper surveys the usual absorbant materials, means of obtainment, their essential characteristics relating to their use and their behaviour under neutron irradiation [fr

  17. Histological examination of the effect of differently fractionated irradiations in rat and mouse organs. Pt. 3

    International Nuclear Information System (INIS)

    Unger, E.

    1984-01-01

    The spleen of rats was irradiated with 50 Gy dose local X-rays in two different fractionation rhythms, i.e. twice a week given high and daily applied lower fractions of radiation. According to the results of 3 H-thymidine autoradiography made after the last irradiation 24 hours later both in the white and the red pulp the labelling index was less on the effect of twice in a week applied high radiation fractions than in case of daily given lower fractions. This indicate in correlation with the results of earlier analogous histological experiments that the damaging effect of rarely given higher fractions of radiation in the spleen is especially obvious. (orig.) [de

  18. Investigation of the bystander effect in MRC5 cells after acute and fractionated irradiation in vitro

    Directory of Open Access Journals (Sweden)

    Shokouhozaman Soleymanifard

    2014-01-01

    Full Text Available Radiation-induced bystander effect (RIBE has been defined as radiation responses observed in nonirradiated cells. It has been the focus of investigators worldwide due to the deleterious effects it induces in nonirradiated cells. The present study was performed to investigate whether acute or fractionated irradiation will evoke a differential bystander response in MRC5 cells. A normal human cell line (MRC5, and a human lung tumor cell line (QU-DB were exposed to 0, 1, 2, and 4Gy of single acute or fractionated irradiation of equal fractions with a gap of 6 h. The MRC5 cells were supplemented with the media of irradiated cells and their micronucleus frequency was determined. The micronucleus frequency after single and fractionated irradiation did not vary significantly in the MRC5 cells conditioned with autologous or QU-DB cell-irradiated media, except for 4Gy where the frequency of micronucleated cells was lower in those MRC5 cells cultured in the media of QU-DB-exposed with a single dose of 4Gy. Our study demonstrates that the radiation-induced bystander effect was almost similar after single acute and fractionated exposure in MRC5 cells.

  19. Investigation of the bystander effect in MRC5 cells after acute and fractionated irradiation in vitro

    International Nuclear Information System (INIS)

    Soleymanifard, Shokouhozaman; Toossi, Mohammad Taghi Bahreyni; Samani, Roghayeh Kamran; Mohebbi, Shokoufeh

    2014-01-01

    Radiation-induced bystander effect (RIBE) has been defined as radiation responses observed in nonirradiated cells. It has been the focus of investigators worldwide due to the deleterious effects it induces in nonirradiated cells. The present study was performed to investigate whether acute or fractionated irradiation will evoke a differential bystander response in MRC5 cells. A normal human cell line (MRC5), and a human lung tumor cell line (QU-DB) were exposed to 0, 1, 2, and 4Gy of single acute or fractionated irradiation of equal fractions with a gap of 6 h. The MRC5 cells were supplemented with the media of irradiated cells and their micronucleus frequency was determined. The micronucleus frequency after single and fractionated irradiation did not vary significantly in the MRC5 cells conditioned with autologous or QU-DB cell-irradiated media, except for 4Gy where the frequency of micronucleated cells was lower in those MRC5 cells cultured in the media of QU-DB-exposed with a single dose of 4Gy. Our study demonstrates that the radiation-induced bystander effect was almost similar after single acute and fractionated exposure in MRC5 cells. (author)

  20. Clinical and immunologic effects of fractionated total lymphoid irradiation in refractory rheumatoid arthritis

    International Nuclear Information System (INIS)

    Trentham, D.E.; Belli, J.A.; Anderson, R.J.; Buckley, J.A.; Goetzl, E.J.; David, J.R.; Austen, K.F.

    1981-01-01

    Ten patients with refractory rheumatoid arthritis were given 3000 rad of fractionated total lymphoid irradiation in an uncontrolled therapeutic trial. Total lymphoid irradiation was associated with objective evidence of considerable clinical improvement in eight patients and with reduced blood lymphocyte counts in all 10. On completion of irradiation, there was an abrogation of lymphocyte reactivity in vitro in the patients with clinical responses, but abnormal antibody activities characteristic of rheumatoid arthritis and normal components of humoral immunity were not suppressed. Partial recrudescence of arthritis occurred shortly after a year after the completion of irradiation and was paralleled by a restitution of lymphocyte concentrations and responsiveness to mitogens to levels similar to those observed before irradiation. These data provide further evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis and demonstrate that total lymphoid irradiation can induce temporary relief, but they do not ascertain whether the natural history of this disease was altered

  1. Clinical and immunologic effects of fractionated total lymphoid irradiation in refractory rheumatoid arthritis

    International Nuclear Information System (INIS)

    Trentham, D.E.; Belli, J.A.; Anderson, R.J.; Buckley, J.A.; Goetzl, E.J.; David, J.R.; Austen, K.F.

    1981-01-01

    Ten patients with refractory rheumatoid arthritis were given 3000 rad of fractionated total lymphoid irradiation in an uncontrolled therapeutic trial. Total lymphoid irradiation was associated with objective evidence of considerable clinical improvement in eight patients and with reduced blood lymphocyte counts in all 10. On completion of irradiation, there was an abrogation of lymphocyte reactivity in vitro in the patients with clinical responses, but abnormal antibody activities characteristic of rheumatoid arthritis and normal components of humoral immunity were not suppressed. Partial recrudescence of arthritis occurred shortly before a year after the completion of irradiation and was paralleled by a restitution of lymphocyte concentrations and responsiveness to mitogens to levels similar to those observed before irradiation. These data provide further evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis and demonstrate that total lymphoid irradiation can induce temporary relief, but they do not ascertain whether the natural history of this disease was altered

  2. Quantitative detection of absorbed dose of irradiated dried fruit by ESR spectroscopy method

    International Nuclear Information System (INIS)

    Li Weiming; Ha Yiming; Zhao Yongfu; Zhang Yanli

    2011-01-01

    Sunflower seeds, walnuts, pistachios, and hazelnuts were used as experimental materials which were irradiated at 1.0, 3.0, 5.0 and 10.0 kGy, respectively. The relationships and correlations between ESR signal intensity and irradiation dosages were studied. The results showed that ESR spectra of irradiated samples were obviously different from that of CK, and the ESR signal intensity was positively related with the irradiation dose. After irradiation, the ESR intensity and spectrum shapes all changed and all four samples were clearly identified irradiated or unirradiated. The appearances of the two weak satellite lines which situated left and right to the intense singlet line in walnuts and pistachios proved the existence of cellulose radical. The detection dose limit of irradiated walnut was 1 kGy, and the detection limits of the other three samples were lower than 1 kGy. In conclusion, the ESR method could be used to irradiated. (authors)

  3. Boll weevil: experimental sterilization of large numbers by fractionated irradiation

    International Nuclear Information System (INIS)

    Haynes, J.W.; Wright, J.E.; Davich, T.B.; Roberson, J.; Griffin, J.G.; Darden, E.

    1978-01-01

    Boll weevils, Anthonomus grandis grandis Boheman, 9 days after egg implantation in the larval diet were transported from the Boll Weevil Research Laboratory, Mississippi State, MS, to the Comparative Animal Research Laboratory, Oak Ridge, TN, and irradiated with 6.9 krad (test 1) or 7.2 krad (test 2) of 60 Co gamma rays delivered in 25 equal doses over 100 h. In test 1, from 600 individual pairs of T (treated) males x N (normal) females, only 114 eggs hatched from a sample of 950 eggs, and 47 adults emerged from a sample of 1042 eggs. Also, from 600 pairs of T females x N males, 6 eggs hatched of a sample of 6 eggs and 12 adults emerged from a sample of 20 eggs. In test 2, from 700 individual pairs of T males x N females, 54 eggs hatched from a sample of 1510, and 10 adults emerged from a sample of 1703 eggs. Also, in T females x N males matings, 1 egg hatched of a sample of 3, and no adults emerged from a sample of 4. Transportation and handling in the 2nd test reduced adult emergence an avg of 49%. Thus the 2 replicates in test 2 resulted in 3.4 x 10 5 and 4.3 x 10 5 irradiated weevils emerging/day for 7 days. Bacterial contamination of weevils was low

  4. Self-shielding and burn-out effects in the irradiation of strongly-neutron-absorbing material

    International Nuclear Information System (INIS)

    Sekine, T.; Baba, H.

    1978-01-01

    Self-shielding and burn-out effects are discussed in the evaluation of radioisotopes formed by neutron irradiation of a strongly-neutron-absorbing material. A method of the evaluation of such effects is developed both for thermal and epithermal neutrons. Gadolinium oxide uniformly mixed with graphite powder was irradiated by reactor-neutrons together with pieces of a Co-Al alloy wire (the content of Co being 0.475%) as the neutron flux monitor. The configuration of the samples and flux monitors in each of two irradiations is illustrated. The yields of activities produced in the irradiated samples were determined by the γ-spectrometry with a Ge(Li) detector of a relative detection efficiency of 8%. Activities at the end of irradiation were estimated by corrections due to pile-up, self-absorption, detection efficiency, branching ratio, and decay of the activity. Results of the calculation are discussed in comparison with the observed yields of 153 Gd, 160 Tb, and 161 Tb for the case of neutron irradiation of disc-shaped targets of gadolinium oxide. (T.G.)

  5. Effect of low molecular fraction of thymus humoral factor on blood formation processes of irradiated mice

    International Nuclear Information System (INIS)

    Stolyarova, T.V.; Skobel'tsyna, E.S.; Grinberg, S.M.; Kruglikov, I.L.; Korotaev, G.K.; Tepelina, O.M.; Il'ina, T.I.

    1982-01-01

    The effect of low-molecular fraction of thymus humoral factor on blood formation in mice irradiated at 4 Gy was studied. It is shown that injection of low-molecular fraction of thymus hymoral factor to irradiated animals affects proliferative processes in spleen and bone marrow, however the degree of the effect depends on the injection scheme of the preparation. Application of mathematical planning methods of the experiment enables to analyze various injection schemes of low-molecular fraction of thymus humoral factor on the investigated indices. The optimal scheme of preparation injection is determined: 1st injection with the dose of 10 mkg/kg following 4 hour after irradiation, 2d injection - with the same dose in 7-21 days

  6. The clinical research on fractionated irradiation treatment with X knife in patients of PD

    International Nuclear Information System (INIS)

    Wei Pengxiang; Chen Xu; Ai Quanshan; Xia Jiyong; Yang Jiongda; Chen Binghuan

    2003-01-01

    Objective: To explore X knife treatment methods and to seek a new effective way for PD therapy. Methods: Sixteen patients of PD were treated by performing VIM with 2 times of X knife fractionated irradiation (interval, 24 h) to a total dose of 140 Gy, and 8 patients of PD were treated by performing VIM with 3 times of X knife fractionated irradiation (interval, 24 h) to a total of dose of 165 Gy. Results: During 3-24 months follow-up after X knife treatment, tremor was stopped in 19 patients and was relived significantly in 5 patients. Rigidity and bradykinesia of PD were relieved slightly. No complications were observed. Conclusion: To perform VIM with X knife fractionated irradiation can be safely and effectively used to treat PD. The tremor of PD can be relieved slightly

  7. Histopathological changes in the irradiated normal organs of guinea pigs with conventional fractionation and hyperfractionation

    International Nuclear Information System (INIS)

    Inomata, Taisuke; Itoh, Satoshi; Tsuboi, Nobuaki

    1998-01-01

    Guinea pigs were divided into groups according to four irradiation schedules : 2 Gy/3 Gy x 1/day, five fractions/week, total 80 Gy/81 Gy (A/C group) and 1.0 Gy/1.5 Gy x 2/day, ten fractions/week, total 80 Gy/81 Gy (B/D group). The A group and the C group pathologically caused severe damage in the kidney six and three months after irradiation, respectively. In the B group pathological analysis suggested that only slight-to-moderate changes were occurred in the Bowman's capsule. The D group caused slight damage in the kidney six months after irradiation. Hyperfractionation (B/D group) used in this protocol can clearly reduce radiation damage in the kidney of guinea pigs as compared with conventional fractionation (A/C group). (author)

  8. Role of Rad52 in fractionated irradiation induced signaling in A549 lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Ghosh, Somnath; Krishna, Malini

    2012-01-01

    The effect of fractionated doses of γ-irradiation (2 Gy per fraction over 5 days), as delivered in cancer radiotherapy, was compared with acute doses of 10 and 2 Gy, in A549 cells. A549 cells were found to be relatively more radioresistant if the 10 Gy dose was delivered as a fractionated regimen. Microarray analysis showed upregulation of DNA repair and cell cycle arrest genes in the cells exposed to fractionated irradiation. There was intense activation of DNA repair pathway-associated genes (DNA-PK, ATM, Rad52, MLH1 and BRCA1), efficient DNA repair and phospho-p53 was found to be translocated to the nucleus of A549 cells exposed to fractionated irradiation. MCF-7 cells responded differently in fractionated regimen. Silencing of the Rad52 gene in fractionated group of A549 cells made the cells radiosensitive. The above result indicated increased radioresistance in A549 cells due to the activation of Rad52 gene.

  9. Fractional Absorption of Active Absorbable Algal Calcium (AAACa and Calcium Carbonate Measured by a Dual Stable-Isotope Method

    Directory of Open Access Journals (Sweden)

    Steven A. Abrams

    2010-07-01

    Full Text Available With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa, obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI, with that of calcium carbonate. In 10 postmenopausal women volunteers aged 59 to 77 years (mean ± S.D., 67 ± 5.3, the fractional calcium absorption of AAACa and CaCO3 was measured by a dual stable isotope method. 44Ca-enriched CaCO3 and AAACa were administered in all subjects one month apart. After a fixed-menu breakfast and pre-test urine collection (Urine 0, 42Ca-enriched CaCl2 was intravenously injected, followed by oral administration of 44Ca-enriched CaCO3 without carrier 15 minutes later, and complete urine collection for the next 24 hours (Urine 24. The fractional calcium absorption was calculated as the ratio of Augmentation of 44Ca from Urine 0 to Urine 24/ augmentation of 42Ca from Urine 0 to Urine 24. Differences and changes of 44Ca and 42Ca were corrected by comparing each with 43Ca. Fractional absorption of AAACa (mean ± S.D., 23.1 ± 6.4, was distinctly and significantly higher than that of CaCO3 (14.7 ± 6.4; p = 0.0060 by paired t-test. The mean fractional absorption was approximately 1.57-times higher for AAACa than for CaCO3. The serum 25(OH vitamin D level was low (mean ± S.D., 14.2 ± 4.95 ng/ml, as is common in this age group in Japan. Among the parameters of the bone and mineral metabolism measured, none displayed a significant correlation with the fractional absorption of CaCO3 and AAACa. Higher fractional absorption of AAACa compared with CaCO3 supports previous reports on the more beneficial effect of AAACa than CaCO3 for osteoporosis.

  10. Dietary enhancement of intestinal radioresistance during fractionated irradiation

    International Nuclear Information System (INIS)

    Pageau, R.; St-Pierre, C.

    1978-01-01

    Rats fed laboratory chow or elemental diet 3 were given fractions of 240 rads of 60 Co γ radiation abdominally (1200 rads/week) until all animals had died. Changes in appetite, body weight, and mortality were monitored as a function of the cumulative dose received. More radiation was needed in the diet-fed group to achieve both 0 and 100% mortality, a difference of 37% at the mean lethal dose level. Both groups developed similar progressive anorexia but the diet-fed animals lost weight more slowly. Data indicate that basic intestinal radioresistance is enhanced by feeding the elemental diet

  11. Monitoring PAI-1 and VEGF Levels in 6 Human Squamous Cell Carcinoma Xenografts During Fractionated Irradiation

    International Nuclear Information System (INIS)

    Bayer, Christine; Kielow, Achim; Schilling, Daniela; Maftei, Constantin-Alin; Zips, Daniel; Yaromina, Ala; Baumann, Michael; Molls, Michael; Multhoff, Gabriele

    2012-01-01

    Purpose: Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine in vivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. Methods and Materials: Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD 50 ). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. Results: Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. Conclusions: These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

  12. Evaluation of {sup 99}Mo/{sup 99m}Tc generator columns after irradiation with different absorbed doses

    Energy Technology Data Exchange (ETDEWEB)

    Fukumori, Neuza T.O.; Mengatti, Jair; Matsuda, Margareth M.N., E-mail: ntfukumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    The {sup 99}Mo/{sup 99m}Tc generator is widely used in nuclear medicine and it consists of a glass column containing Teflon® strips and alumina in which {sup 99}Mo produced by {sup 235}U fission is adsorbed. The {sup 99}mTcO4- eluate shall meet the sterile and pyrogen free conditions for injectable radiopharmaceuticals as determined by the Good Manufacturing Practices. The purpose of this study was to evaluate the feasibility of using gamma radiation in the sterilization of the {sup 99}Mo/{sup 99m}Tc generator column and the influence on the elution efficiency. Alumina-containing columns were irradiated with 10, 15, 25 and 50 kGy absorbed doses. Alumina samples and control (non-irradiated) were submitted to X-ray diffraction and the combined use of scanning electron microscopy and elemental analysis. Teflon® samples were evaluated by thermogravimetry (TGA) and differential scanning calorimetry (DSC). X-ray diffractograms and micrographies with elemental analysis showed no significant changes in the crystalline structure of the alumina because it was stable α-Al{sub 2}O{sub 3}. TGA demonstrated that higher doses showed changes in lower temperatures and times than the control material. For DSC the higher the absorbed dose, the greater the polymer chain breakage and crosslinking in the material. The generator system without radioactivity was set up with the irradiated columns and the eluates demonstrated to be sterile and pyrogen free. The effects of different absorbed doses on the generator column, although some reported changes in the materials, demonstrated that the sterilization of the columns by irradiation with gamma rays as an alternative to wet heat sterilization is feasible from a technical and financial point of view. (author)

  13. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

    Directory of Open Access Journals (Sweden)

    Ganesh Chandra Jagetia

    2015-01-01

    Full Text Available Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation.

  14. Effect-independent measures of tissue responses to fractionated irradiation

    International Nuclear Information System (INIS)

    Thames, H.D. Jr.

    1984-01-01

    Tissue repair factors measure the sparing that can be achieved from dose fractionation in the absence of proliferation. Four repair factors are analysed in these terms: Fsub(R),Fsub(rec), the ratio of linear-quadratic survival model parameters β/α and the half-time Tsub(1/2) for intracellular repair processes. Theoretically, Fsub(R) and Fsub(rec) are increasing functions of D 1 , and thus depend on level of effect. This is confirmed by analysis of skin reactions after multifractionated radiation. By contrast, β/α is effect-independent as a measure of repair capacity in skin, gut, and bone marrow, tissues for which it is reasonable to assume that survival of identifiable target cells is the primary determinant of the endpoint. For a functional endpoint not clearly connected with the depletion of a specific target-cell population (late fibrotic reactions in the kidney), there was an increase in β/α with increased levels of injury, but this was statistically insignificant. Tsub(1/2) is independent of fraction size in skin, gut, and spinal cord, and is longer (1.5 hours) in the late-reacting tissues (lung and spinal cord) than in those that react acutely (Tsub(1/2) less than 1 hour), with skin as the exception (Tsub(1/2) approx. 1.3 hours). (author)

  15. Mathematical models and specific absorbed fractions of photon energy in the nonpregnant adult female and at the end of each trimester of pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Stabin, M.G.; Watson, E.E.; Cristy, M.; Ryman, J.C.; Eckerman, K.F. [Oak Ridge National Lab., TN (United States); Davis, J.L. [Tennessee Univ., Chattanooga, TN (United States); Marshall, D. [Florida Univ., Gainesville, FL (United States). Dept. of Nuclear Engineering; Gehlen, M.K. [San Diego State Univ., CA (United States)

    1995-05-08

    Mathematical phantoms representing the adult female at three, six, and nine months of gestation are described. They are modifications of the 15-year-old male/adult female phantom (15-AF phantom) of Cristy and Eckerman (1987). The model of uterine contents includes the fetus, fetal skeleton, and placenta. The model is suitable for dose calculations for the fetus as a whole; individual organs within the fetus (other than the skeleton) are not modeled. A new model for the nonpregnant adult female is also described, comprising (1) the 15-AF phantom; (2) an adjustment to specific absorbed fractions for organ self-dose from photons to better match Reference Woman masses; and (3) computation of specific absorbed fractions with Reference Woman masses from ICRP Publication 23 for both penetrating and nonpenetrating radiations. Specific absorbed fractions for photons emitted from various source regions are tabulated for the new non;pregnant adult female model and the three pregnancy models.

  16. Application of average adult Japanese voxel phantoms to evaluation of photon specific absorbed fractions

    International Nuclear Information System (INIS)

    Sato, Kaoru; Manabe, Kentaro; Endo, Akira

    2012-01-01

    Average adult Japanese male (JM-103) and female (JF-103) voxel (volume pixel) phantoms newly constructed at the Japan Atomic Energy Agency (JAEA) have average characteristics of body sizes and organ masses in adult Japanese. In JM-103 and JF-103, several organs and tissues were newly modeled for dose assessments based on tissue weighting factors of the 2007 Recommendations of the International Commission on Radiological Protection(ICRP). In this study, SAFs for thyroid, stomach, lungs and lymphatic nodes of JM-103 and JF-103 phantoms were calculated, and were compared with those of other adult Japanese phantoms based on individual medical images. In most cases, differences in SAFs between JM-103, JF-103 and other phantoms were about several tens percent, and was mainly attributed to mass differences of organs, tissues and contents. Therefore, it was concluded that SAFs of JM-103 and JF-103 represent those of average adult Japanese and that the two phantoms are applied to dose assessment for average adult Japanese on the basis of the 2007 Recommendations. (author)

  17. Long-term survival of skin allografts in mice treated with fractionated total lymphoid irradiation

    International Nuclear Information System (INIS)

    Slavin, S.; Strober, S.; Fuks, Z.; Kaplan, H.S.

    1976-01-01

    Treatment of recipient Balb/c mice with fractionated, high-dose total lymphoid irradiation, a procedure commonly used in the therapy of human malignant lymphomas, resulted in fivefold prolongation of the survival of C57BL/Ka skin allografts despite major histocompatibility differences between the strains (H-2/sup d/ and H-2/sup b/, respectively). Infusion of 10 7 (C57BL/Ka x Balb/c)F 1 bone marrow cells after total lymphoid irradiation further prolonged C57BL/Ka skin graft survival to more than 120 days. Total lymphoid irradiation may eventually prove useful in clinical organ transplantation

  18. Patient absorbed radiation doses estimation related to irradiation anatomy; Estimativa de dose absorvida pelo paciente relacionada a anatomia irradiada

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes, E-mail: prof.flavio@gmail.com, E-mail: amanda-a-soares@hotmail.com, E-mail: gabriellygkahl@gmail.com [Instituto Federal de Eduacao, Ciencia e Tecnologia de Santa Catarina (IFSC), Florianopolis, SC (Brazil)

    2014-07-01

    Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector.

  19. Performance of super-absorbent polymer as an internal curing agent for self-compacting concrete

    Directory of Open Access Journals (Sweden)

    Al-Hubboubi Suhair

    2018-01-01

    Full Text Available Internal curing agent by using super-absorbent polymer was present in this study, its effect on the properties of self-compacting concrete was evaluated .The SAP content in the concrete mix was 0.5 % by weight of cement. Three procedures for curing were adopted; curing in water, curing in water and air and curing in polyethylene sealed bags. Fresh concrete tests conducted to assess the self-compactability of the produced concrete. Moreover, compressive and splitting strength tests were carried out. The testing program had been extended to the age of 90 days.The use of super-absorbent polymer did not affect the fresh state characteristics of the studied SCC and achieved an increase in both compressive and tensile strengths as compared to the reference concrete mix.

  20. EXPERIMENTAL INVESTIGATION OF IRRADIATION-DRIVEN HYDROGEN ISOTOPE FRACTIONATION IN ANALOGS OF PROTOPLANETARY HYDROUS SILICATE DUST

    Energy Technology Data Exchange (ETDEWEB)

    Roskosz, Mathieu; Remusat, Laurent [IMPMC, CNRS UMR 7590, Sorbonne Universités, Université Pierre et Marie Curie, IRD, Muséum National d’Histoire Naturelle, CP 52, 57 rue Cuvier, Paris F-75231 (France); Laurent, Boris; Leroux, Hugues, E-mail: mathieu.roskosz@mnhn.fr [Unité Matériaux et Transformations, Université Lille 1, CNRS UMR 8207, Bâtiment C6, F-59655 Villeneuve d’Ascq (France)

    2016-11-20

    The origin of hydrogen in chondritic components is poorly understood. Their isotopic composition is heavier than the solar nebula gas. In addition, in most meteorites, hydrous silicates are found to be lighter than the coexisting organic matter. Ionizing irradiation recently emerged as an efficient hydrogen fractionating process in organics, but its effect on H-bearing silicates remains essentially unknown. We report the evolution of the D/H of hydrous silicates experimentally irradiated by electrons. Thin films of amorphous silica, amorphous “serpentine,” and pellets of crystalline muscovite were irradiated at 4 and 30 keV. For all samples, irradiation leads to a large hydrogen loss correlated with a moderate deuterium enrichment of the solid residue. The entire data set can be described by a Rayleigh distillation. The calculated fractionation factor is consistent with a kinetically controlled fractionation during the loss of hydrogen. Furthermore, for a given ionizing condition, the deuteration of the silicate residues is much lower than the deuteration measured on irradiated organic macromolecules. These results provide firm evidence of the limitations of ionizing irradiation as a driving mechanism for D-enrichment of silicate materials. The isotopic composition of the silicate dust cannot rise from a protosolar to a chondritic signature during solar irradiations. More importantly, these results imply that irradiation of the disk naturally induces a strong decoupling of the isotopic signatures of coexisting organics and silicates. This decoupling is consistent with the systematic difference observed between the heavy organic matter and the lighter water typically associated with minerals in the matrix of most carbonaceous chondrites.

  1. Prooxidate - antioxidate homeostasis in guinea pigs after fractional low-dose irradiation

    International Nuclear Information System (INIS)

    Baraboj, V.A.; Olyijnik, S.A.; Khmelevs'kij, Yi.V.

    1993-01-01

    We studied the influence of fractional total irradiation in the total dose of 1 Gy on the amount of lipids peroxide oxidation (LPO) products and ascorbic acid in the spleen, intestine and brain of guinea-pigs. The obtained date suggest that it is advisable to use ascorbic acid to correct postirradiation changes in the organism exposed to small doses of ionizing radiation

  2. Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma

    International Nuclear Information System (INIS)

    Sakamoto, Touru; Shirato, Hiroki; Takeichi, Norihito; Aoyama, Hidefumi; Fukuda, Satoshi; Miyasaka, Kazuo

    2001-01-01

    Purpose: The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment. Methods and materials: In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months)x12)]. Results: The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6±10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9±14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st, 2nd, 3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P=0.025) and 3rd year (P=0.018) were significantly slower than the rate before irradiation. Conclusions: The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss

  3. Histologic alterations of the normal bladder wall following to variably fractionated irradiation - an experimentation on animals

    International Nuclear Information System (INIS)

    Fueller, J.; Fritzsche, V.; Kob, D.; Arndt, J.; Kriester, A.; Friedrich-Schiller-Universitaet, Jena

    1986-01-01

    The histopathologic alterations of the bladder wall were investigated in 180 rabbits irradiated with different fractionations and total focal doses. Animals sacrified one week after the end of irradiation showed alterations of the urothelium (desquamation, increased polymorphism of nuclei vacuolizations) as well as oedematous and hyperemic reactions in submucosa and muscularis. These alterations became stronger when the single and total focal dose and the ret values were increased. Animals sacrified three to six months after the end of irradiation showed dystrophic-sclerotic processes as well as vascular obliterations in the submucosa and muscularis. The alterations were only clearly visible in case of a total focal dose of at least 30 Gy. With regard to a minimization of histopathologic alterations of the bladder wall, a fractionation of 1.5 Gy per day has to be considered as favorable in radiotherapy of the carcinoma of the urinary bladder. (orig.) [de

  4. A non-invasive method for fractionated steriotactic irradiation of brain tumors with linear accelerator

    International Nuclear Information System (INIS)

    Hariz, M.I.; Laitinen, L.V.; Henriksson, R.; Saeterborg, N.-E.; Loefroth, P.-O.

    1990-01-01

    A new technique for fractionated stereotactic irradiation of intracranial lesions is described. The treatment is based on a versatile, non-invasive interface for stereotactic localization of the brain target imaged by computed tomography (CT), angiography or magnetic resonance tomography (MRT), and subsequent repetitive stereotactic irradiation of the target using a linear accelerator. The fractionation of the stereotactic irradiation was intended to meet the requirements of the basic principles of radiobiology. The radiophysical evaluation using phantoms, and the clinical results in a small number of patients, demonstrated a good reproducibilit between repeated positionings of the target in the isocenter of the accelerator, and a high degree of accuracy in the treatment of brain lesions. (authors). 28 refs.; 11 figs.; 1 tab

  5. Chromosomal aberrations in Cynomolgus peripheral lymphocytes during and after fractionated whole-body γ-irradiation

    International Nuclear Information System (INIS)

    Guedeney, G.; Malarbet, J.L.; Doloy, M.T.

    1989-01-01

    Cynomolgus monkeys (Macaca fascicularis) were exposed to fractionated whole-body γ-irradiation at high and low dose rates for 4 or 5 weeks. The time-dependence of chromosomal aberrations was studied in relation to the number of lymphocytes during irradiation and after exposure for periods of up to about 600 days for chromosomal aberrations and 200 days for lymphocyte counts. Additivity of the daily effects on the number of chromosomal aberrations was observed during the exposures. Immediately after the end of the exposures the number of chromosomal aberrations decreased to reach low values. The disappearance of chromosomal aberrations seemed to be related to recovery of the lymphocyte counts. The data presented here emphasize the different kinetic patterns of chromosomal aberrations after fractionated and acute irradiation. (author)

  6. Model of the absorbed dose on a small sphere into a gamma irradiation field

    International Nuclear Information System (INIS)

    Mangussi, J.

    2009-01-01

    Several models of the absorbed dose calculated as the energy deposited by the secondary electrons on a small volume sphere are presented. The calculations use the Compton scattering of a uniform photon beam in water, the photon attenuation and the electron stopping power are included. The sphere total absorbed dose is due to the stopping of the electrons generated in three regions: into the sphere volume, ahead and behind the sphere volume. Calculations are performed for spheres of different radius and placed at various depth of the vacuum - water interface. (author)

  7. In-vivo evaluation of standard man model absorbed fractions using /sup 99m/Tc-sulfur colloid

    International Nuclear Information System (INIS)

    Jones, J.P.; Wagner, J.; Brill, A.B.

    1976-01-01

    Results are reported from a study performed to check how well the calculated absorbed radiation dose fraction data (S-factors) given in MIRD Pamphlet No. 5 and related reports apply to living patients administered radionuclides. An external target region was defined on the skin of the Snyder-Fisher phantom, anterior to and overlaying the center of the liver. This target was a 5 cm square by 0.089 cm thick slab of LiF, and the S-factors were computed for this target and uniform distributions of /sup 99m/Tc in the liver and spleen. Experimentally, this target was represented by placing thirteen LiF TLD's of the same thickness in a correspondingly positioned 5 cm square area. An experiment performed with the Mr. Adam phantom showed good agreement between the measured (TLD) and calculated (S-factor) doses. In the patient studies, the group of thirteen TLD's was correspondingly positioned, and the measured TLD dose compared to that calculated from the patient cumulated activity and the Snyder-Fisher phantom S-factors. In most cases, these doses agreed to within 30 percent, although larger discrepancies were observed with non-standard sized patients. Based upon these results, it is desirable to make further investigations of this type, especially with lower energy gamma emitters, and the methods of dose and activity measurement used in this study should be useful unless the photon energy is too low, or the source activity changes rapidly with time

  8. Absorbed dose determination in external beam radiotherapy. An international code of practice for dosimetry based on standards of absorbed dose to water

    International Nuclear Information System (INIS)

    2000-01-01

    The International Atomic Energy Agency published in 1987 an International Code of Practice entitled 'Absorbed Dose Determination in Photon and Electron Beams' (IAEA Technical Reports Series No. 277 (TRS-277)), recommending procedures to obtain the absorbed dose in water from measurements made with an ionization chamber in external beam radiotherapy. A second edition of TRS-277 was published in 1997 updating the dosimetry of photon beams, mainly kilovoltage X rays. Another International Code of Practice for radiotherapy dosimetry entitled 'The Use of Plane-Parallel Ionization Chambers in High Energy Electron and Photon Beams' (IAEA Technical Reports Series No. 381 (TRS-381)) was published in 1997 to further update TRS-277 and complement it with respect to the area of parallel-plate ionization chambers. Both codes have proven extremely valuable for users involved in the dosimetry of the radiation beams used in radiotherapy. In TRS-277 the calibration of the ionization chambers was based on primary standards of air kerma; this procedure was also used in TRS-381, but the new trend of calibrating ionization chambers directly in a water phantom in terms of absorbed dose to water was introduced. The development of primary standards of absorbed dose to water for high energy photon and electron beams, and improvements in radiation dosimetry concepts, offer the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. The dosimetry of kilovoltage X rays, as well as that of proton and heavy ion beams, interest in which has grown considerably in recent years, can also be based on these standards. Thus a coherent dosimetry system based on standards of absorbed dose to water is possible for practically all radiotherapy beams. Many Primary Standard Dosimetry Laboratories (PSDLs) already provide calibrations in terms of absorbed dose to water at the radiation quality of 60 Co gamma rays. Some laboratories have extended calibrations to high energy photon and

  9. Changes in the fraction of total hypoxia and hypoxia subtypes in human squamous cell carcinomas upon fractionated irradiation: Evaluation using pattern recognition in microcirculatory supply units

    International Nuclear Information System (INIS)

    Maftei, Constantin-Alin; Bayer, Christine; Shi, Kuangyu; Astner, Sabrina T.; Vaupel, Peter

    2011-01-01

    Background and purpose: Evaluate changes in total hypoxia and hypoxia subtypes in vital tumor tissue of human head and neck squamous cell carcinomas (hHNSCC) upon fractionated irradiation. Materials and methods: Xenograft tumors were generated from 5 hHNSCC cell lines (UT-SCC-15, FaDu, SAS, UT-SCC-5 and UT-SCC-14). Hypoxia subtypes were quantified in cryosections based on (immuno-)fluorescent marker distribution patterns of Hoechst 33342 (perfusion), pimonidazole (hypoxia) and CD31 (endothelium) in microcirculatory supply units (MCSUs). Tumors were irradiated with 5 or 10 fractions of 2 Gy, 5×/week. Results: Upon irradiation with 10 fractions, the overall fraction of hypoxic MCSUs decreased in UT-SCC-15, FaDu and SAS, remained the same in UT-SCC-5 and increased in UT-SCC-14. Decreases were observed in the proportion of chronically hypoxic MCSUs in UT-SCC-15, in the fraction of acutely hypoxic MCSUs in UT-SCC-15 and SAS, and in the percentage of hypoxemically hypoxic MCSUs in SAS tumors. After irradiation with 5 fractions, there were no significant changes in hypoxia subtypes. Changes in the overall fraction of hypoxic MCSUs were comparable to corresponding alterations in the proportions of acutely hypoxic MCSUs. There was no correlation between radiation resistance (TCD 50 ) and any of the investigated hypoxic fractions upon fractionated irradiation. Conclusions: This study shows that there are large alterations in the fractions of hypoxia subtypes upon irradiation that can differ from changes in the overall fraction of hypoxic MCSUs.

  10. Repair of skin damage during fractionated irradiation with gamma rays and low-LET carbon ions

    International Nuclear Information System (INIS)

    Ando, Koichi; Koike, Sachiko; Uzawa, Akiko; Takai, Nobuhiko; Fukawa, Takeshi; Furusawa, Yoshiya; Aoki, Mizuho; Hirayama, Ryoichi

    2006-01-01

    In clinical use of carbon-ion beams, a deep-seated tumor is irradiated with a Spread-Out Bragg peak (SOBP) with a high-linear energy transfer (LET) feature, whereas surface skin is irradiated with an entrance plateau, the LET of which is lower than that of the peak. The repair kinetics of murine skin damage caused by an entrance plateau of carbon ions was compared with that caused by photons using a scheme of daily fractionated doses followed by a top-up dose. Right hind legs received local irradiations with either 20 keV/μm carbon ions or γ rays. The skin reaction of the irradiated legs was scored every other day up to Day 35 using a scoring scale that consisted of 10 steps, ranging from 0.5 to 5.0. An isoeffect dose to produce a skin reaction score of 3.0 was used to obtain a total dose and a top-up dose for each fractionation. Dependence on a preceding dose and on the time interval of a top-up dose was examined using γ rays. For fractionated γ rays, the total dose linearly increased while the top-up dose linearly decreased with an increase in the number of fractions. The magnitude of damage repair depended on the size of dose per fraction, and was larger for 5.2 Gy than 12.5 Gy. The total dose of carbon ions with 5.2 Gy per fraction did not change till 2 fractions, but abruptly increased at the 3rd fraction. Factors such as rapid repopulation, induced repair and cell cycle synchronization are possible explanations for the abrupt increase. As an abrupt increase/decrease of normal tissue damage could be caused by changing the number of fractions in carbon-ion radiotherapy, we conclude that, unlike photon therapy, skin damage should be carefully studied when the number of fractions is changed in new clinical trials. (author)

  11. Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

    International Nuclear Information System (INIS)

    Luka, S.; Marks, J.E.

    2015-01-01

    The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

  12. Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Luka, S.; Marks, J.E.

    2015-01-15

    The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

  13. Altered fractionation of hemithorax irradiation for pleural mesothelioma and failure patterns after treatment

    Energy Technology Data Exchange (ETDEWEB)

    Holsti, L.R. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Pyrhoenen, S. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Kajanti, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Maentylae, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Mattson, K. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Maasilta, P. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Kivisaari, L. [Dept. of Diagnostic Radiology, Helsinki University Central Hospital (Finland)

    1997-09-01

    Malignant pleural mesothelioma is a rare malignancy with a bleak prognosis. The role of radiotherapy has not yet been clarified. Our aim was to study the effect of altered fractionation on mesothelioma. We have treated 57 patients, 41 males and 16 females, with hemithorax irradiation with six different fractionation schedules. All the patients have been included in a combined modality program consisting of surgery followed by chemotherapy and finally by hemithorax irradiation. The radiotherapy schedules used were: I. Conventional fractionation of 20 Gy in 10 fractions over 12 days. II, Split-course radiotherapy 55 Gy in 25 fractions of 2.2 Gy over 7 weeks (a two weeks rest halfways) followed by a boost dose of 15 Gy over 8 days to the major tumour area. III. Hyperfractionation of 70 Gy over 7 weeks, 1.25 Gy BID with a 6-h interval and a 10-day rest halfways. IV. Combined hyperfractionation and hypofractionation, 35 Gy hyperfractionation in 28 fractions (1.25 Gy BID with a 6-h interval) over three weeks followed by 36 Gy hypofractionation 9 fractions of 4 Gy given every other day over 3 weeks to the major tumour areas only. V. Hypofractionation of 38.5 Gy over 15 days (9x3.5 Gy). VI. Combined conventional radiotherapy and hypofractionation with 20 Gy given conventionally in 10 fractions followed by 10 fractions of 3 Gy over two weeks, overall time 4 weeks. The 2-year survival rate of all patients was 21% and the 5-year survival rate 9%. Two patients are still alive more than 6 and 9 years after radiotherapy. Progression occurred after surgery in four patients, during and after chemotherapy in 22 patients and after completed radiotherapy in 29 patients. The pattern of progression was similar in each treatment group. (orig.).

  14. Analysis of electrophoretic soil humic acids fractions by reversed-phase high performance liquid chromatography with on-line absorbance and fluorescence detection.

    Science.gov (United States)

    Trubetskoj, Oleg A; Richard, Claire; Guyot, Ghislain; Voyard, Guillaume; Trubetskaya, Olga E

    2012-06-22

    A combination of reversed-phase high performance liquid chromatography (RP HPLC) with on-line absorbance and fluorescence detection was used for analysis of chernozem soil humic acids (HAs) and their fractions A, B and C+D with different electrophoretic mobility (EM) and molecular size (MS). Samples were injected onto the column at the identical volume and absorbance. All chromatograms exhibit the resolution of seven peaks. The estimation of relative recovery of HAs and fractions from the reverse-phase column has been done. High MS fraction A, which possesses the low EM, is essentially more hydrophobic (73% of the fraction amount remained adsorbed on the column) and aliphatic than medium MS and EM fraction B (33% of the fraction amount remained adsorbed on the column). The most hydrophilic and aromatic properties belong to low MS fraction C+D, which possess the highest EM and practically was not adsorbed on the column. The hydrophobicity of the bulk HAs lies within the range of fractions hydrophobicity. The absorption spectra of bulk HAs, electrophoretic fractions A, B, C+D and corresponding RP HPLC peaks were featureless but had differences in the values of absorbance ratio at 300 and 400 nm (A3/A4). For fractions A and B this ratio gradually decreased from peak 1 to 7 (from 3.05 to 2.80 and 3.00 to 2.40, respectively). This trend was less pronounced in HAs and practically absent in fraction C+D, where ratio A3/A4 varied within a small range. The strong relationship between fluorescence properties, EM, MS, polarity and aliphaticity/aromaticity of HAs fractions was found. Humic and protein-like fluorescence had different polarity nature. The protein-like fluorescence is located in humic material which irreversibly adsorbed on the reverse-phase column and not subjected to RP HPLC characterization. The humic-like fluorescence at Ex/Em 270/450 nm is mostly located in the hydrophilic peak of low MS fraction C+D. Taking into account that high MS fraction A consisted

  15. Fractionated homogenous total-body irradiation prior to bone marrow transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Duehmke, E; Brix, F; Hebbinghaus, D; Jensen, M; Wendhausen, H; Schmitz, N

    1985-03-01

    At the University of Kiel, myeloid and acute lymphatic leukemia is treated since 1983 by total-body irradiation applied prior to bone marrow transplantation. Dose deviations in the midplane caused by the irregular surface and tissue inhomogeneities of the patient are reduced down to +-3.5% compared to the central ray, with the help of CT-based individual compensators. This method prevents above all an excessive dose to the lungs. The radiobiologic advantages of fractionated irradiation have been employed for all patients treated hitherto (n = 9). At present, a total body dose of 12 Gy in six fractions is applied within three days. There were no undesired acute radiogenic reactions except a mild acute mucositis found in all patients. Chronic side effects, especially in the lungs, were not demonstrated, too. However, the average follow-up time of 149 days has been rather short. One patient died from relapse of leukemia after a total dose of 10 Gy, another patient died because the transplanted bone marrow was rejected, and a third died from catheter sepsis. Six out of nine patients are in complete remission with a maximum index of Karnofsky. The limited experiences gained hitherto show that the homogeneous accelerated-fractionated total-body irradiation offers essential advantages compared to non-compensated single dose irradiation with respect to the prevention of undesired radiogenic effects in sound tissues and that its therapeutic efficacy is at least the same.

  16. Combined treatment of the immunoconjugate bivatuzumab mertansine and fractionated irradiation improves local tumour control in vivo

    International Nuclear Information System (INIS)

    Gurtner, Kristin; Hessel, Franziska; Eicheler, Wolfgang; Dörfler, Annegret; Zips, Daniel; Heider, Karl-Heinz; Krause, Mechthild; Baumann, Michael

    2012-01-01

    Background and purpose: To test whether BIWI 1 (bivatuzumab mertansine), an immunoconjugate of the humanized anti-CD44v6 monoclonal antibody BIWA 4 and the maytansinoid DM1, given simultaneously to fractionated irradiation improves local tumour control in vivo compared with irradiation alone. Material and methods: For growth delay, FaDu tumours were treated with 5 intravenous injections (daily) of phosphate buffered saline (PBS, control), BIWA 4 (monoclonal antibody against CD44v6) or BIWI 1 (bivatuzumab mertansine) at two different dose levels (50 μg/kg DM1 and 100 μg/kg DM1). For local tumour control, FaDu tumours received fractionated irradiation (5f/5d) with simultaneous PBS, BIWA 4 or BIWI 1 (two dose levels). Results: BIWI 1 significantly improved local tumour control after irradiation with 5 fractions already in the lower concentration. The dose modifying factor of 1.9 is substantial compared to the majority of other modifiers of radiation response. Conclusion: Because of the magnitude of the curative effect, this approach is highly promising and should be further evaluated using similar combinations with improved tumour-specificity.

  17. The effects of single and fractionated irradiation of the trunk in rats

    International Nuclear Information System (INIS)

    Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

    1985-01-01

    The effect of whole trunk irradiation on the development of functional damage was investigated in rats. Rats were restrained without anesthesia such that only the trunk (from clavicle to pelvic girdle) was irradiated with a Cs-137 irradiator at a dose rate of 8.5 Gy/min. Rats received single doses of 9.4, 11.7, 14.1, or 16.4 Gy; or total doses of 11.7, 14.1, 16.4, 18.8, or 21.1 Gy in two equal fractions separated by 4-6 hr. Except for the highest dose in both schedules, there was no lethality; 16.4 Gy reduced survival to 45% and 21.1 Gy in two fractions reduced survival to 77% by day 150. From day 10 to day 150 there was a dose-dependent reduction in weight for both schedules, with the two-dose response displaced from the single dose response by ≅ 6 Gy. A whole-body plethysmograph was used to measure respiration frequency. There was no increase in respiration frequency compared to control animals, except for the highest single dose - 16.4 Gy producing an increase that was manifested from 10 to 150 days. The authors conclude that, in this rat trunk irradiation model, fractionation into two equal doses separated by 4-6 hr produces a sparing effect of ≅ 6 Gy as measured by delay in weight gain (presumably a result of irradiation of the abdomen); and ≥ 6 Gy as measured by survival and increased respiration frequency (a result of irradiation of the thorax)

  18. Audiological assessment before and after fractionated stereotactic irradiation for vestibular schwannoma

    International Nuclear Information System (INIS)

    Sakamoto, T.; Sato, N.; Inuyama, Y.; Shirato, H.; Kagei, K.; Fukuda, S.; Miyasaka, K.; Sawamura, Y.; Suzuki, K.; Takizawa, H.; Hokunan, K.; Isu, T.

    1998-01-01

    Purpose: To find the audiological outcome after LINAC-based fractionated stereotactic irradiation (STI). Materials and methods: Twenty-four patients with vestibular schwannoma treated by fractionated STI between 1991 and 1997 had measurable hearing before STI and were followed audiologically for more than 6 months. The pure tone average (PTA) was measured by averaging the air-conduction threshold for five main frequencies (250-4000 Hz) before and periodically after STI in the 24 patients. Several possible prognostic factors for hearing preservation (defined as a PTA change at the last follow-up of less than 10 dB) were investigated. The median follow-up time was 22 months, ranging from 5 to 69 months. The irradiation schedule was 36 Gy in 20 fractions in 5 weeks to 44 Gy in 22 fractions in 6 weeks followed by 4 Gy/1 fraction boost. Results: The pure tone average before STI was distributed from 7 to 73 dB. Fifty percent of patients showed a change in PTA of less than 10 dB, 79.2% of patients showed a change in PTA of less than 20 dB and 20.8% of patients showed a change in PTA of more than 21 dB at the last follow-up. Only one patient (4%) became deaf. Cases with a sudden loss of hearing were more likely to experience hearing preservation than those with gradual loss of hearing (P<0.05). The mean age was younger in patients whose hearing was preserved (P<0.05). Poor pretreatment PTA appeared to linearly correspond to the changes in PTA (regression coefficient 0.78). The size of the tumor was not related to the change in PTA. No relationship was observed between the maximum or peripheral dose and the PTA change. The real benefit of stereotactic boost after small-field fractionated irradiation was not certain. Conclusion: Fractionated STI produced a hearing preservation rate compatible with meticulously collimated multi-spots single fraction irradiation. Further follow-up is required to confirm the long-term benefits of fractionation. (Copyright (c) 1998 Elsevier

  19. Radioresistance of immunized animals in internal irradiation

    International Nuclear Information System (INIS)

    Kal'nitskij, S.A.; Ponomareva, T.V.; Shubik, V.M.

    1981-01-01

    The influence of an immunization with bacterial vaccines and antimeasles-gamma-globulin on the radioresistance of raceless white mice was studied. In the vaccinated animals a higher survival rate and duration of life, a better general condition and a better curve of weight and stronger physical stamina were stated compared to the merely irradiated mice. The higher radioresistance is ascribed to the stimulation of cellular and humoral factors of the unspecific protection against infection, to the repair of the lymphoid tissue of the immunized animals and to the decrease in autosensibilization. (author)

  20. Wholesomeness studies in the International Food Irradiation Project

    International Nuclear Information System (INIS)

    Elias, P.S.

    1980-01-01

    Despite more than 25 years history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and it is required to carry out scientific investigations to reassure the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subject to the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans. (Kitajima, A.)

  1. Effect of intra-peritoneal fludarabine on rat spinal cord tolerance to fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, V; Ruifrok, A C.C.; Price, R E; Brock, W A; Hittelman, W N; Plunkett, W K; Ang, K K

    1995-07-01

    The effect of fludarabine (9-{beta}-d-arabinosyl-2-fluoroadenine-5'-monophosphate), an adenine nucleoside analogue, on the tolerance of the spinal cord to fractionated irradiation was studied in a rat model. Anesthesized female Fisher 344 rats received irradiation to 2 cm of the cervical spine with a telecobalt unit (dose rate 1.14 Gy/min). Radiation was administered in two, four or eight fractions spread over a 48-h period with or without fludarabine. Animals assigned to combined therapy received two daily intraperitoneal injections of fludarabine (150 mg/kg) given 3 h prior to the first daily radiation fraction. It was found that fludarabine reduced the iso-effect dose required to induce leg paresis at 9 months after irradiation for all fractionation schedules. Dose modification factors of 1.23, 1.29 and greater than 1.27 were obtained for two, four and eight fractions, respectively. Fitting the data with the direct analysis method of Thames et al. with an incomplete repair model [18] showed that the potentiating effect of fludarabine may be mediated through reduction in the number of 'tissue-rescuing units' (lnK). Alpha and {beta} values were slightly but not significantly decreased, whereas the ({alpha}({beta})) ratio was unchanged. These features suggest that fludarabine did not significantly inhibit cellular repair processes but rather reduced the spinal cord tolerance by a fixed additive toxic effect on the same target cells. In rodent models, the combination of fludarabine and fractionated radiation has previously been found to yield a therapeutic gain, i.e., the drug enhanced tumor response to a greater extent than it reduced normal tissue tolerance. However, given our results, caution should be exercised in extrapolating these findings to the clinic. Normal tissue reactions will have to be monitored rigorously in phase I clinical studies.

  2. Calculation of absorbed fractions to human skeletal tissues due to alpha particles using the Monte Carlo and 3-d chord-based transport techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, J.G. [Institute of Radiation Protection and Dosimetry, Av. Salvador Allende s/n, Recreio, Rio de Janeiro, CEP 22780-160 (Brazil); Watchman, C.J. [Department of Radiation Oncology, University of Arizona, Tucson, AZ, 85721 (United States); Bolch, W.E. [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL, 32611 (United States); Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2007-07-01

    Absorbed fraction (AF) calculations to the human skeletal tissues due to alpha particles are of interest to the internal dosimetry of occupationally exposed workers and members of the public. The transport of alpha particles through the skeletal tissue is complicated by the detailed and complex microscopic histology of the skeleton. In this study, both Monte Carlo and chord-based techniques were applied to the transport of alpha particles through 3-D micro-CT images of the skeletal microstructure of trabecular spongiosa. The Monte Carlo program used was 'Visual Monte Carlo-VMC'. VMC simulates the emission of the alpha particles and their subsequent energy deposition track. The second method applied to alpha transport is the chord-based technique, which randomly generates chord lengths across bone trabeculae and the marrow cavities via alternate and uniform sampling of their cumulative density functions. This paper compares the AF of energy to two radiosensitive skeletal tissues, active marrow and shallow active marrow, obtained with these two techniques. (authors)

  3. Physical models, cross sections, and numerical approximations used in MCNP and GEANT4 Monte Carlo codes for photon and electron absorbed fraction calculation.

    Science.gov (United States)

    Yoriyaz, Hélio; Moralles, Maurício; Siqueira, Paulo de Tarso Dalledone; Guimarães, Carla da Costa; Cintra, Felipe Belonsi; dos Santos, Adimir

    2009-11-01

    Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most of them used Monte Carlo radiation transport codes. Despite the widespread use of these codes due to the variety of resources and potentials they offered to carry out dose calculations, several aspects like physical models, cross sections, and numerical approximations used in the simulations still remain an object of study. Accurate dose estimate depends on the correct selection of a set of simulation options that should be carefully chosen. This article presents an analysis of several simulation options provided by two of the most used codes worldwide: MCNP and GEANT4. For this purpose, comparisons of absorbed fraction estimates obtained with different physical models, cross sections, and numerical approximations are presented for spheres of several sizes and composed as five different biological tissues. Considerable discrepancies have been found in some cases not only between the different codes but also between different cross sections and algorithms in the same code. Maximum differences found between the two codes are 5.0% and 10%, respectively, for photons and electrons. Even for simple problems as spheres and uniform radiation sources, the set of parameters chosen by any Monte Carlo code significantly affects the final results of a simulation, demonstrating the importance of the correct choice of parameters in the simulation.

  4. Short-term irradiation of the glioblastoma with high-dosed fractions

    International Nuclear Information System (INIS)

    Hinkelbein, W.; Bruggmoser, G.; Schmidt, M.; Wannenmacher, M.

    1984-01-01

    Compared to surgery alone, postoperative radiotherapy leads with glioblastomas (grade IV gliomas) to a significant improvement of the therapeutic results. The prolongation of survival time, however, is to a large extent compensated by the therapy itself (it normally implicates hospitalisation). Therefore, we tested the efficiency of rapid course irradiation with high fractions. 70 patients were treated daily with individual fractions of 3.5 Gy, 4 to 6 fractions per week. The entire dose amounted to 31.5 to 38.5 Gy. The average survival time was 33.5 weeks corresponding to the survival time known from the combined surgical and radiotherapeutical treatment of glioblastomas. An effective increase in therapy-free survival time seems possible, especially when the entire focal dose does not exceed 35 Gy. It is remarkable that the patients with the maximum exposure did not have the longest survival times and rates. Living conditions for the patients were similar to those with conventional fractioning, or even better. Rapid course irradiation with high fractions and a limited total dose (35 Gy) presently is - apart from the accelerated superfractioning - a successful measure to prolong the therapyfree survival time for patients with grade IV gliomas. (orig.) [de

  5. Retrieval of Leaf Area Index (LAI and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR from VIIRS Time-Series Data

    Directory of Open Access Journals (Sweden)

    Zhiqiang Xiao

    2016-04-01

    Full Text Available Long-term high-quality global leaf area index (LAI and fraction of absorbed photosynthetically active radiation (FAPAR products are urgently needed for the study of global change, climate modeling, and many other problems. As the successor of the Moderate Resolution Imaging Spectroradiometer (MODIS sensor, the Visible Infrared Imaging Radiometer Suite (VIIRS will continue to provide global environmental measurements. This paper aims to generate longer time series Global LAnd Surface Satellite (GLASS LAI and FAPAR products after the era of the MODIS sensor. To ensure spatial and temporal consistencies between GLASS LAI/FAPAR values retrieved from different satellite observations, the GLASS LAI/FAPAR retrieval algorithms were adapted in this study to retrieve LAI and FAPAR values from VIIRS surface reflectance time-series data. After reprocessing of the VIIRS surface reflectance to remove remaining effects of cloud contamination and other factors, a database generated from the GLASS LAI product and the reprocessed VIIRS surface reflectance for all Benchmark Land Multisite Analysis and Intercomparison of Products (BELMANIP sites was used to train general regression neural networks (GRNNs. The reprocessed VIIRS surface reflectance data from an entire year were entered into the trained GRNNs to estimate the one-year LAI values, which were then used to calculate FAPAR values. A cross-comparison indicates that the LAI and FAPAR values retrieved from VIIRS surface reflectance were generally consistent with the GLASS, MODIS and Geoland2/BioPar version 1 (GEOV1 LAI/FAPAR values in their spatial patterns. The LAI/FAPAR values retrieved from VIIRS surface reflectance achieved good agreement with the GLASS LAI/FAPAR values (R2 = 0.8972 and RMSE = 0.3054; and R2 = 0.9067 and RMSE = 0.0529, respectively. However, validation of the LAI and FAPAR values derived from VIIRS reflectance data is now limited by the scarcity of LAI/FAPAR ground measurements.

  6. Understanding and predicting the behaviour of silver base neutron absorbers under irradiations; Comprehension et prediction du comportement sous irradiation neutronique d`alliages absorbants a base d`argent

    Energy Technology Data Exchange (ETDEWEB)

    Desgranges, C

    1998-12-31

    The effect of neutron irradiation induced transmutations on the swelling of AgInCd (AIC) alloys used as neutron absorber in the control rods of Pressurized Water Reactors has been studied both experimentally and theoretically. Effective atomic volumes have been determined in synthetic AgCdInSn alloys with various compositions and containing fcc and hc phases, representative of irradiated AIC (Sn is a transmutation product). Swelling is shown to result first from the transmutation of Ag into Cd and of In into Sn, both with larger effective volume than the mother atom, and second from grain boundaries precipitation of s still less dense hc phase when solid solubility of transmuted products is exceeded. For both fcc and hc phases, we have determined profiles at the temperatures in the vicinity of the operating temperature. Unusual characteristics of second phase growth at grain boundaries induced by transmutations are identified on a simple binary alloy model: kinetics is controlled by irradiation temperature which scales diffusivities and flux which scales transmutation rates, as well as by the grain size in the underlying matrix. To address the AgInCdSn alloys, a novel technique is proposed to model diffusion in multicomponent alloys. It is based on a linearization of a simple atomistic model. With a single set of parameters, for each phase, our model well reproduces our interdiffusion measurements in quaternary alloys as well as existing interdiffusion experiments in binary alloys. Finally this diffusion model implemented with a moving interface algorithm is used to model the growth of the second phase induced by transmutation in the AIC under irradiation. (authors) 74 refs.

  7. Evaluation of neutron irradiation fields for BNCT by using absorbed dose in a phantom

    International Nuclear Information System (INIS)

    Aizawa, O.

    1993-01-01

    In a previous paper, the author defined the open-quotes irradiation timeclose quotes as the time of irradiation in which the maximum open-quotes total background doseclose quotes becomes 2,500 RBE-cGy. In this paper, he has modified the definition a little as the time of irradiation in which the maximum open-quotes lμg/g B-10 doseclose quotes becomes 3,000 RBE-cGy, because he assumed that normal tissue contained 1μg/g B-10. Moreover, he has modified the dose criteria for BNCT as follows: The open-quotes eye doseclose quotes, open-quotes total body doseclose quotes and open-quotes except-head doseclose quotes should be less that 200, 100 and 50 RBE-cGy, respectively. He has added one more criterion for BNCT that the thermal neutron fluence at the tumor position should be over 2.5x10 12 n/cm 2 at the open-quotes irradiation timeclose quotes. The distance from the core side to the irradiation port in the open-quotes old configurationclose quotes of the Musashi reactor (TRIGA-II, 100kW) was 160 cm. He is now planning to design an eccentric core and to move the reactor core nearer to the irradiation port, distance between the core side and the irradiation port to be 140, 130 and 120cm. The other assumptions used in this paper are as follows: (1) The B-10 concentrations in tumor are 30 and/or 10μg/g. (2) The depth of the tumor is 5.0 cm to 5.5 cm from the surface. (3) The RBE values used are 1.0 for all gamma rays and 2.3 for B 10 (n,α) reaction products. (4) The RBE values for neutrons are the following three cases: the first case is using 1.6 for all neutrons; the second one is using 3.2 for non-thermal neutrons and 1.6 for thermal neutrons; the third case is using 4.8 for fast neutrons, 3.2 for faster epithermal and epithermal neutrons, and 1.6 for thermal neutrons

  8. Evaluation of the analgesic activity and safety of ketorolac in whole body fractionated gamma irradiated animals

    Directory of Open Access Journals (Sweden)

    Sara Aly

    2015-06-01

    Full Text Available This study was performed to evaluate the analgesic activity and the toxicity of ketorolac in normal and fractionated (1.5 Gy/day/4 days γ-irradiated animals. Determination of brain serotonin content and serum prostaglandin level were also undertaken. The analgesic activity was tested using formalin test, at three dose levels (15, 30 and 60 mg/kg after 1 and 7 days post radiation exposure. LD50 determinations and assessment of liver and kidney function tests were performed. Our results indicated marked analgesic effects on the early and late phases of nociception. Double treatment with ketorolac and irradiation increased brain serotonin content. The acute LD50 of ketorolac was decreased in irradiated animals as compared to the LD50 of normal animals. Double treatment with ketorolac and irradiation induced an elevation of gastric mucin content, urea and BUN levels on the 1st day post irradiation, whereas, albumin level was lowered and globulin level was elevated after 7 days post irradiation. Depending on this study the dose of ketorolac used for treating cancer patients addressed to radiotherapy should be reduced, however, this requires further clinical confirmation.

  9. Effective dose as an irritating influence during fractionated γ-irradiation

    International Nuclear Information System (INIS)

    Karpov, V.N.; Ushakov, I.B.; Davydov, B.I.

    1990-01-01

    The study of early neurological disturbances (END) in rats after fractionated γ-irradiation with doses of 37.5-225 Gy at dose rate of 30.11 Gy/min has demonstrated that the initial response of animals to pulse ionizing radiation is a function of the electric charge induced by ionizing radiation. A change in the probability of occurrence of each of the END symptoms, with the increased intervals between exposures, is merely an indirect indication of the eliminating mechanisms and is intricately connected with the irritating charge value. The proposed empiric relationships permit to correlate the probability of END symptom occurrence with the continuous quantitative parameter of fractionated irradiation, that is, with an effective dose as an analogue of the irritating effect

  10. Sterilization of boll weevil pupae with fractionated doses of gamma irradiation

    International Nuclear Information System (INIS)

    Haynes, J.W.; Mitlin, N.; Davich, T.B.; Dawson, J.R.; McGovern, W.L.; McKibben, G.H.

    1977-01-01

    Fractionated doses of 6,250-8,000 rads of gamma irradiation administered to pupae of the boll weevil, Anthonomus grandis Boh., sexually sterilized both sexes. Mortality of males thus treated with 6,250 and 8,000 rads via fractionation was 14% and 27% respectively, by 5 days posttreatment compared with 46% mortality when an equivalent acute dose was administered to newly emerged adults. Pheromone production of males irradiated at 6,250 rads was one-third that of the control for the first 4 days, but equal that of the control during 5-11 days posttreatment. This procedure lends itself to the large-scale sterilization of weevils needed in an eradication program. This technique is applicable to other insects that are highly susceptible to acute doses

  11. Large effect of irradiance on hydrogen isotope fractionation of alkenones in Emiliania huxleyi

    Science.gov (United States)

    van der Meer, Marcel T. J.; Benthien, Albert; French, Katherine L.; Epping, Eric; Zondervan, Ingrid; Reichart, Gert-Jan; Bijma, Jelle; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2015-07-01

    The hydrogen isotopic (δD) composition of long-chain alkenones produced by certain haptophyte algae has been suggested as a potential proxy for reconstructing paleo sea surface salinity. However, environmental parameters other than salinity may also affect the δD of alkenones. We investigated the impact of the level of irradiance on hydrogen isotopic fractionation of alkenones versus growth water by cultivating two strains of the cosmopolitan haptophyte Emiliania huxleyi at different light intensities. The hydrogen isotope fractionation decreased by approximately 40‰ when irradiance was increased from 15 to 200 μmol photons m-2 s-1 above which it was relatively constant. The response is likely a direct effect of photosystem I and II activity as the relationship of the fractionation factor α versus light intensity can be described by an Eilers-Peeters photosynthesis model. This irradiance effect is in agreement with published δD data of alkenones derived from suspended particulate matter collected from different depths in the photic zone of the Gulf of California and the eastern tropical North Pacific. However, haptophyte algae tend to bloom at relatively high light intensities (>500 μmol photons m-2 s-1) occurring at the sea surface, at which hydrogen isotope fractionation is relatively constant and not affected by changes in light intensity. Alkenones accumulating in the sediment are likely mostly derived from these surface water haptophyte blooms, when the largest amount of biomass is produced. Therefore, the observed irradiance effect is unlikely to affect the applicability of the hydrogen isotopic composition of sedimentary long chain alkenones as a proxy for paleosalinity.

  12. A study of the effect of fractional gamma irradiation of leptospirae

    International Nuclear Information System (INIS)

    Vasilevska, M.; Khristova, M.; Yankova, N.; Pandev, I.

    1977-01-01

    In view of the theoretical and practical interest in obtaining antigens from killed leptospirae for immune or diagnostic serums, a two hour leptospiral culture from the pathogenic strain Pomona (Calapica) was fractionally gamma-irradiated with a total dose of 2 Mrad. Changes were observed in the size, motility and survival duration of the leptospiral strains. The results are interpreted and compared with those of single administration of the same dose, studied in a previous work. (author)

  13. Sound attenuation of a finite length dissipative flow duct silencer with internal mean flow in the absorbent

    Science.gov (United States)

    Cummings, A.; Chang, I.-J.

    1988-11-01

    Internal mean flow within the pores of a bulk-reacting porous acoustic absorbent, driven by mean static pressure gradients, is shown here to be an important feature of the acoustics of dissipative silencers in flow ducts, particularly in the case of internal combustion engine exhaust silencers. Theoretical treatments are presented here, both to describe the effect of internal flow on the bulk acoustic perties of the porous medium and to find the effect of the absorbent in situ, in the form of the sound transmission loss of the silencer. The measured transmission loss of an experimental silencer is compared to predicted data and good agreement between the two is obtained. The effects of mean fluid flow in the central passage and internal flow in the absorbent are separately demonstrated.

  14. Impact of drug permeability of blood-brain barrier after whole brain conventional fractionation irradiation

    International Nuclear Information System (INIS)

    Zhang Longzhen; Cao Yuandong; Chen Yong; Yu Changzhou; Zhuang Ming

    2006-01-01

    Objective: To explore the effect of drug permeability in rat blood-brain barrier(BBB) after different doses of whole brain conventional fractionation irradiation in rats and provide the experimental basis for the optimum time of clinical chemotherapy. Methods: According to different irradiation doses, 100 adult Sprague-Dowley rats were divided randomly into 5 groups: the normal control group(0 Gy); 10 Gy; 20 Gy; 30 Gy; and 40 Gy group. All rats were exposed to conventional fractionation(2 Gy/d, 5 d/w) with 60 Co γ-ray. MTX(25 mg/kg) was injected through the tail mainline 16 hours after whole brain irradiation. Cerebrospinal fluid(CSF) and blood were collected 2 hours later. Those samples were used to assay MTX concentration using RP-HPLC. Results: MTX mean concentrations in CSF was 0.07, 0.08, 0.12, 0.24, 0.23 mg/L in the control, 10 Gy, 20 Gy, 30 Gy, 40 Gy groups, respectively. All the data was analyzed with rank test of transform. MTX concentration of CSF was significantly different except the control and 10 Gy, 30 Gy and 40 Gy group. MTX concentration of blood was not significantly different in all groups (P>0.05). Conclusions: Irradiation can directly damage the function of BBB. BBB would be opened gradually following the increase of irradiation dose. It could be considered as the optimum time of chemotherapy when the whole brain irradiation ranges from 20 Gy to 30 Gy. (authors)

  15. Treatment results by uneven fractionated irradiation, low-dose rate telecobalt therapy as a boost, and intraoperative irradiation for malignant glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Shogo; Takai, Yoshihiro; Nemoto, Kenji; Ogawa, Yoshihiro; Kakuto, Yoshihisa; Hoshi, Akihiko; Sakamoto, Kiyohiko; Kayama, Takamasa; Yoshimoto, Takashi (Tohoku Univ., Sendai (Japan). School of Medicine)

    1992-08-01

    The prognosis of malignant glioma is extremely poor. We applied conventionally fractionated irradiation combined with 1-(4-aminio-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), uneven fractionated irradiation with ACNU, low dose rate telecobalt therapy as a boost, and intraoperative irradiation against 110 malignant gliomas to investigate the efficacy of these methods as alternative treatments for malignant glioma. Although local tumor control by uneven fractionated irradiation was better than that by the other methods, no significant improvement was obtained in survival rates. As a result of multiple regression analysis, age and histology were major factors for survival rates, and the difference of treatment methods was not important. Both low-dose rate telecobalt therapy as a boost and intraoperative irradiation showed little advantage because of the high risk of brain necrosis associated with them. (author).

  16. Changes in some blood lipid fractions in whole-body irradiated rats as influenced by some radioprotectors

    International Nuclear Information System (INIS)

    Yousri, R.M.; Roushdy, H.; Gawish, M.A.M.

    1991-01-01

    The effect of sublethal and lethal total body gamma irradiation on some serum lipid fractions in male rats was investigated. The protective efficacy of estradiol and/or α-tocopherol was also studied. The results of this study demonstrate that the lethally irradiated rats showed significant alteration in serum triglycerides, cholesterol, total lipids and phospholipids level. Estradiol exerted a benefical effect on lipid fractions after one and two days post lethal α-irradiation (8 Gy). No consistent radioprotective effect of tocopherol could be detected on the levels of serum lipid fractions. This finding was also observed when both radioprotectors were used. (orig.) [de

  17. Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

    International Nuclear Information System (INIS)

    Doerr, W.; Kummermehr, J.

    1990-01-01

    Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

  18. Content of DNA in cancerous tumours of the breast before and after large-fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shiukashvili, N N

    1976-07-01

    The article presents the results of microspectrophotometric investigation of DNA in different cancerous tumors of the breast gland before and after large-fractionated irradiation. The study of quantitative content of DNA in the non-irradiated tumors of the breast of different histological structure showed that parenchymatous cells are characterized by a definite variety in the DNA content with a different level of their polyploidy. This points to the fact that different histological forms of the breast cancer are distinguished by the character of the components differentiation. The comparative assessment of the ploidity of the cancerous cells of irradiated and non-irradiated tumors revealed that under the changed conditions of co-existence in all histological forms of cancer new modal classes of the cells develop and general quantity of the DNA content decreases. This testifies to the fact that the histological forms of the breast cancer are not equal sensitive tumors. A microspectrophotometric study of the breast tumors makes it possible to reveal the injury of the malignant tumor cells in the initial period of irradiation, when it is difficult to discover clear-cut dystrophical changes during histological investigation.

  19. The international fusion materials irradiation facility

    International Nuclear Information System (INIS)

    Shannon, T.E.; Cozzani, F.; Crandall, D.H.; Wiffen, F.W.; Katsuta, H.; Kondo, T.; Teplyakov, V.; Zavialsky, L.

    1994-01-01

    It is widely agreed that the development of materials for fusion systems requires a high flux, 14 MeV neutron source. The European Union, Japan, Russia and the US have initiated the conceptual design of such a facility. This activity, under the International Energy Agency (IEA) Fusion Materials Agreement, will develop the design for an accelerator-based D-Li system. The first organizational meeting was held in June 1994. This paper describes the system to be studied and the approach to be followed to complete the conceptual design by early 1997

  20. Simultaneous PLK1 inhibition improves local tumour control after fractionated irradiation

    International Nuclear Information System (INIS)

    Krause, Mechthild; Kummer, Berit; Deparade, Andre; Eicheler, Wolfgang; Pfitzmann, Dorothee; Yaromina, Ala; Kunz-Schughart, Leoni A.

    2013-01-01

    Purpose: Polo-like kinase 1 (PLK1) plays an important role in mitotic progression, is frequently overexpressed and associated with a poor prognosis of cancer patients, thus providing a promising target in anticancer treatment. Aim of the current project was to evaluate the effect of the novel PLK1 inhibitor BI 6727 in combination with irradiation. Material and methods: In vitro proliferation and radiation cell survival assays as well as in vivo local tumour control assays after single treatment and combined radiation and drug application were carried out using the squamous cell carcinoma models A431 and FaDu. In addition, cell cycle phases were monitored in vitro and in vivo. Results: BI 6727 showed a dose-dependent antiproliferative effect and an increase in the mitotic fraction. BI 6727 alone reduced clonogenic cell survival, while radiosensitivity in vitro (SF2) and in vivo (single-dose TCD 50 under clamped hypoxia) was not affected. In contrast, local tumour control was significantly improved after application of BI 6727 simultaneously to fractionated irradiation (A431: TCD 50 = 60.5 Gy [95% C.I. 57; 63] after IR alone and <30 Gy after combined treatment; FaDu: 49.5 Gy [43; 56 Gy] versus 32.9 Gy [26; 40]). Conclusions: Despite the lack of direct cellular radiosensitisation, PLK1 inhibition with BI 6727 during fractionated irradiation significantly improves local tumour control when compared to irradiation alone. This result is likely explained by a considerable effect on cell cycle and an independent cytotoxic potential of BI 6727

  1. Standardized methods to verify absorbed dose in irradiated food for insect control. Proceedings of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    2001-03-01

    Irradiation to control insect infestation of food is increasingly accepted and applied, especially as a phytosanitary treatment of food as an alternative to fumigation. However, unlike other processes for insect control, irradiation does not always result in immediate insect death. Thus, it is conceivable that fresh and dried fruits and tree nuts, which have been correctly irradiated to meet insect disinfestation/quarantine requirements, may still contain live insects at the time of importation. There is, however, a movement by plant quarantine authorities away from inspecting to ensure the absence of live insects in imported consignments towards examining through administrative procedures that a treatment required by law has been given. Nevertheless, there is a need to provide plant quarantine inspectors with a reliable objective method to verify that a minimum absorbed dose of radiation was given to supplement administrative procedures. Such an objective method is expected to bolster the confidence of the inspectors in clearing the consignment without delay and to facilitate trade in irradiated commodities. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture initiated a co-ordinated research project (CRP) in 1994 to generate data on the verification of absorbed dose of irradiation in fresh, dried fruits and tree nuts for insect disinfestation/quarantine purposes. A standardized label dose indicator available commercially was used to verify the minimum/maximum absorbed dose of the irradiated commodities for these purposes as required by regulations in certain countries. It appears that such a label dose indicator with certain modifications could be made available to assist national authorities and the food industry to verify the absorbed dose of irradiation to facilitate trade in such irradiated commodities. This TECDOC reports on the accomplishments of this co-ordinated research project and includes the papers presented by the participants

  2. Single-dose and fractionated irradiation of four human lung cancer cell lines in vitro

    International Nuclear Information System (INIS)

    Brodin, O.; Lennartsson, L.; Nilsson, S.

    1991-01-01

    Four established human lung cancer cell lines were exposed to single-dose irradiation. The survival curves of 2 small cell lung carcinomas (SCLC) were characterized by a limited capacity for repair with small and moderate shoulders with extrapolation numbers (n) of 1.05 and 1.60 respectively. Two non-small cell lung carcinoma (NSCLC) cell lines, one squamous cell (SQCLC) and one large cell (LCLC) had large shoulders with n-values of 73 and 15 respectively. The radiosensitivity when measured as D 0 did not, however, differ as much from cell line to cell line, with values from 1.22 to 1.65. The surviving fraction after 2 Gy (SF2) was 0.24 and 0.42 respectively in the SCLC cell lines and 0.90 and 0.88 respectively in the NSCLC cell lines. Fractionated irradiation delivered according to 3 different schedules was also investigated. All the schedules delivered a total dose of 10 Gy in 5 days and were applied in 1, 2 and 5 Gy dose fractions respectively. Survival followed the pattern found after single-dose irradiation; it was lowest in the SCLC cell line with the lowest SF and highest in the two NSCLC cell lines. In the SCLC cell lines all schedules were approximately equally efficient. In the LCLC and in the SQCLC cell lines, the 5 Gy schedule killed more cells than the 1 and 2 Gy schedules. The results indicate that the size of the shoulder of the survival curve is essential when choosing the most tumoricidal fractionation schedule. (orig.)

  3. Repopulation capacity during fractionated irradiation of squamous cell carcinomas and glioblastomas in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Budach, Wilfried; Gioioso, Danielle; Taghian, Alphonse; Stuschke, Martin; Suit, Herman D

    1997-10-01

    Purpose: Determination of clonogenic cell proliferation of three highly malignant squamous cell carcinomas (SCC) and two glioblastoma cell lines during a 20-day course of fractionated irradiation under in vitro conditions. Methods and Materials: Tumor cells in exponential growth phase were plated in 24-well plastic flasks and irradiated 24 h after plating with 250 kV x-rays at room temperature. Six fractions with single doses between 0.6 and 9 Gy were administered in 1.67, 5, 10, 15, and 20 days. Colony growth was monitored for at least 60 days after completion of irradiation. Wells with confluent colonies were considered as 'recurrences' and wells without colonies as 'controlled'. The dose required to control 50% of irradiated wells (WCD{sub 50}) was estimated by a logistic regression for the different overall treatment times. The effective doubling time of clonogenic cells (T{sub eff}) was determined by a direct fit using the maximum likelihood method. Results: The increase of WCD{sub 50} within 18.3 days was highly significant for all tumor cell lines accounting for 7.9 and 12.0 Gy in the two glioblastoma cell lines and for 12.7, 14.0, and 21.7 Gy in the three SCC cell lines. The corresponding T{sub eff}s were 4.4 and 2.0 days for glioblastoma cell lines and 2.4, 4.2, and 1.8 days for SCC cell lines. Population doubling times (PDT) of untreated tumor cells ranged from 1.0 to 1.9 days, showing no correlation with T{sub eff}s. T{sub eff} was significantly longer than PDT in three of five tumor cell lines. No significant differences were observed comparing glioblastomas and SCC. Increase of WCD{sub 50} with time did not correlate with T{sub eff} but with T{sub eff}* InSF2 (surviving fraction at 2 Gy). Conclusion: The intrinsic ability of SCC and glioblastoma cells to repopulate during fractionated irradiation could be demonstrated. Repopulation induced dose loss per day depends on T{sub eff} and intrinsic radiation sensitivity. Proliferation during treatment was

  4. [Internal fixation treatment of multiple rib fractures with absorbable rib-connecting-pins].

    Science.gov (United States)

    Liu, Jinliang; Li, Keyao; He, Jianning

    2011-01-01

    To study the indications, methods, and therapeutic effect of absorbable rib-connecting-pins fixation in the treatment of multiple rib fractures. Between March 2007 and September 2009, 40 patients with multiple rib fractures received internal fixation with absorbable rib-connecting-pins, including 8 one-side flail chest and 1 two-side flail chest. There were 32 males and 8 females with an average age of 39.8 years (range, 25-72 years). The injury was caused by traffic accident in 32 cases, falling from height in 6 cases, and blunt hitting in 2 cases. Preoperatively, imaging data of the chest X-ray or spiral CT three-dimensional (3D) examination showed that all patients had multiple ribs fractures and displacement. The number of fractured ribs was 4-10 (median, 6), and the fracture location ranged from the 2nd to the 10th ribs. Of them, 28 cases were accompanied by hemathorax, pneumothorax or hemopneumothorax; 5 cases by thoracic organ injury; and 10 cases by other part trauma. The time from injury to hospitalization was less than 1 day in 26 cases, 1-3 days in 12 cases, and 3-6 days in 2 cases, and the time from hospitalization to operation was 3 hours to 3 days (mean, 1.2 days). The median fixation rib number was 5 (range, 3-8). The mean operative time, the time in bed, and hospitalization days were 32 minutes (range, 15-50 minutes), 4.5 days (range, 2-7 days), and 11.2 days (range, 5-18 days), respectively. All incisions healed by first intention. No pulmonary infection, pulmonary atelectasis, intrathoracic infection or other complications occurred. All cases were followed up 6-12 months (mean, 8 months). PaO2 [(86.6 +/- 2.2) mmHg (1 mm Hg = 0.133 kPa)] and SpO2 (97.2% +/- 0.6%) at 2 hours after operation were obviously improved when compared with preoperative ones (PaO2 (53.6 + 4.7) mm Hg and SpO2 (86.2% + 1.8%)], showing significant differences (t = 2.971, P = 0.005; t = 2.426, P = 0.020). The chest X-ray films or spiral CT 3D indicated that fracture of rib

  5. Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun-Jung, E-mail: forejs2@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jun Won, E-mail: JUNWON@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Yoo, Hyun, E-mail: gochunghee@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kwak, Woori, E-mail: asleo02@snu.ac.kr [Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-747 (Korea, Republic of); Choi, Won Hoon, E-mail: wonhoon@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Cho, Seoae, E-mail: seoae@cnkgenomics.com [C& K Genomics, Seoul National University Mt.4-2, Main Bldg. #514, SNU Research Park, NakSeoungDae, Gwanakgu, Seoul 151-919 (Korea, Republic of); Choi, Yu Jeong, E-mail: yunk9275@daum.net [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Yoon-Jin, E-mail: yjlee8@kirams.re.kr [Division of Radiation Effects, Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul 139-760 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

    2015-08-14

    We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm{sup 2} fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL

  6. Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

    International Nuclear Information System (INIS)

    Lee, Eun-Jung; Kim, Jun Won; Yoo, Hyun; Kwak, Woori; Choi, Won Hoon; Cho, Seoae; Choi, Yu Jeong; Lee, Yoon-Jin; Cho, Jaeho

    2015-01-01

    We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm 2 fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL-33

  7. Pathologic changes in the hearts of beagles irradiated with fractionated fast neutrons or photons

    International Nuclear Information System (INIS)

    Zook, B.C.; Bradley, E.W.; Casarett, G.W.; Rogers, C.C.

    1981-01-01

    Thirty-nine adult male purebred beagles received either fast-neutron or photon irradiation to the right thorax to determine the effects on pulmonary tissue. The right atrium, a small portion of the right ventricle, and the right anterior abdomen were included in the field. Twenty-four dogs (six/group) received fast neutrons with a mean energy of 15 MeV to doses of 1000, 1500, 2250, or 3375 rad in four fractions per week for 6 weeks. Fifteen dogs received 3000, 4500, or 6750 rad of photons (five/group) in an identical fractionation pattern. Fourteen dogs died or were euthanatized in extremis between 47 and 708 days after radiation because of radiation damage to digestive organs. Six other dogs died of anesthetic accidents between 196 and 1144 days after radiation; these deaths were probably related to hepatic dysfunction. Two neutron-irradiated dogs developed cardiac neoplasms after 396 and 1624 days. One dog died of a myocardial infarct and one died of an unrelated infection. The major atrial lesions were hemorrhage and necrosis of myocardial cells in dogs that died 47-109 days postirradiation. Myocardial and endocardial fibrosis were most extensive in dogs that died 84 or more days following irradiation. All beagles had degenerative and occlusive vascular changes associated with atrial lesions. The relative biological effectiveness of fast neutrons for pathologic injury of the heart was estimated to be between 4 and 5

  8. Reemergence of apoptotic cells between fractionated doses in irradiated murine tumors

    International Nuclear Information System (INIS)

    Meyn, R.E.; Hunter, N.R.; Milas, L.

    1994-01-01

    The purpose of this investigation was to follow up our previous studies on the development of apoptosis in irradiated murine tumors by testing whether an apoptotic subpopulation of cells reemerges between fractionated exposures. Mice bearing a murine ovarian carcinoma, OCa-I, were treated in vivo with two fractionation protocols: two doses of 12.5 Gy separated by various times out to 5 days and multiple daily fractions of 2.5 Gy. Animals were killed 4 h after the last dose in each protocol, and the percent apoptosis was scored from stained histological sections made from the irradiated tumors according to the specific features characteristic of this mode of cell death. The 12.5+12.5 Gy protocol yielded a net total percent apoptosis of about 45% when the two doses were separated by 5 days (total dose = 25 Gy), whereas the 2.5 Gy per day protocol yielded about 50% net apoptotic cells when given for 5 days (total dose = 12.5 Gy). These values are to be compared to the value of 36% apoptotic cells that is yielded by large single doses (> 25 Gy). Thus, these results indicate that an apoptotic subpopulation of cells reemerged between the fractions in both protocols, but the kinetics appeared to be delayed in the 12.5+12.5 Gy vs. the multiple 2.5 Gy protocol. This reemergence of cells with the propensity for radiation-induced apoptosis between fractionated exposures is consistent with a role for this mode of cell death in the response of tumors to radiotherapy and may represent the priming of a new subpopulation of tumor cells for apoptosis as part of normal tumor homeostasis to counterbalance cell division. 25 refs., 3 figs., 1 tab

  9. Single fraction prophylactic cranial irradiation for small cell carcinoma of the lung

    International Nuclear Information System (INIS)

    Brewster, A.E.; Hopwood, P.; Stout, R.; Burt, P.A.; Thatcher, N.

    1995-01-01

    The effectiveness of a single 8-Gy fraction prophylactic cranial irradiation regime was assessed in 106 patients with small-cell carcinoma of the lung. All patients had limited stage disease and received combination chemotherapy consisting of either cisplatin or carboplatin with ifosfamide, etoposide, and vincristine (VICE). Cranial irradiation was administered 48 h after the first cycle of chemotherapy and was well tolerated. Actual 2-year survival was 35% and cranial relapse occurred in 22% of those patients who achieved complete remission. This compares favourably with a cranial relapse rate of 45% incomplete remitters previously reported with the same chemotherapy regime after a minimum follow-up of 2 years where PCI was not used. Formal psychometric testing was performed retrospectively on a series of 25 long-term survivors of whom 14 were taken from this reported series. Whilst 75% of patients were impaired on at least one test with 68% performing badly in the most complex task, this was not associated with clinically detectable neurological damage and the patients did not complain of memory or concentration difficulties. In conclusion, single fraction PCI, when used with platinum based combination chemotherapy, appears to be equally effective but may be less neurotoxic than the more standard fractionated regimes

  10. Hippocampal Neuron Number Is Unchanged 1 Year After Fractionated Whole-Brain Irradiation at Middle Age

    International Nuclear Information System (INIS)

    Shi Lei; Molina, Doris P.; Robbins, Michael E.; Wheeler, Kenneth T.; Brunso-Bechtold, Judy K.

    2008-01-01

    Purpose: To determine whether hippocampal neurons are lost 12 months after middle-aged rats received a fractionated course of whole-brain irradiation (WBI) that is expected to be biologically equivalent to the regimens used clinically in the treatment of brain tumors. Methods and Materials: Twelve-month-old Fischer 344 X Brown Norway male rats were divided into WBI and control (CON) groups (n = 6 per group). Anesthetized WBI rats received 45 Gy of 137 Cs γ rays delivered as 9 5-Gy fractions twice per week for 4.5 weeks. Control rats were anesthetized but not irradiated. Twelve months after WBI completion, all rats were anesthetized and perfused with paraformaldehyde, and hippocampal sections were immunostained with the neuron-specific antibody NeuN. Using unbiased stereology, total neuron number and the volume of the neuronal and neuropil layers were determined in the dentate gyrus, CA3, and CA1 subregions of hippocampus. Results: No differences in tissue integrity or neuron distribution were observed between the WBI and CON groups. Moreover, quantitative analysis demonstrated that neither total neuron number nor the volume of neuronal or neuropil layers differed between the two groups for any subregion. Conclusions: Impairment on a hippocampal-dependent learning and memory test occurs 1 year after fractionated WBI at middle age. The same WBI regimen, however, does not lead to a loss of neurons or a reduction in the volume of hippocampus

  11. Chromosome aberrations of the peripheral lymphocytes in rabbits exposed to single and fractionated whole-body x-irradiations

    International Nuclear Information System (INIS)

    Tamura, Hiroaki; Sakurai, Masaharu; Sugahara, Tsutomu.

    1978-01-01

    The changes in the frequency of peripheral lymphocytes with chromosome aberrations were observed during or after irradiation of rabbits exposed to fractionated or single whole-body irradiations. In rabbits given daily fractionated whole-body irradiations the incidence of the aberrations showed a linear increase in the first week; however, the incidence decreased thereafter though exposures were repeated. The lymphocyte count tended to decrease as the number of irradiations increased. In rabbits exposed to a single dose of 250 R or 500 R the incidence of aberrations rapidly decreased over a period of 10 days following irradiation, and then showed a little change thereafter. The lymphocyte count in the peripheral blood reached a nadir 2 - 5 days after irradiation, and then started to increase gradually. It was speculated that there are two types of lymphocytes, long-lived and short-lived, in the peripheral blood of rabbits, both of which are PHA-committed. (auth.)

  12. Nd:YAG laser irradiation on temporary teeth carious tissue using 12% diamine silver fluoride as a photo-absorber - a morphological study

    International Nuclear Information System (INIS)

    Calmon, Andrea de Avillez

    2001-01-01

    Since Nd:YAG laser radiation was first introduced in Dentistry various photo-absorbers were employed with the intent of improving its efficacy when used on dental carious tissue. The purpose of the present study was to analyze the influence of this radiation using Scanning and Optical microscopy over carious tissue of primary teeth using two photo-absorbers. 15 primary human teeth were used and, in each one, 3 cavity preparations were performed. Specimens were then submitted to an in vitro demineralizing environment during 18 days. Two of the cavities of each specimen were laser irradiated using the Nd:YAG laser with 60 mJ of energy per pulse, 10 Hz and average power of 0,6 W. The 12% diamine silver fluoride or the mineral coal were used as photo-absorbers. The third cavity of the specimens was used as a control and received no laser irradiation. Samples were transversally cut and the section analyzed by SEM and OM. Results showed that the 12% diamine silver fluoride is an efficient photo-absorber and, when used it the Nd:YAG laser, leading to melting and resolidification of the carious tissue. It can be concluded that the 12% diammine silver fluoride presents advantages over the mineral coal as a photo absorber when used in primary teeth as it promotes and improves the efficacy of laser irradiation. This substance also works as a barrier on the carie progression in deeper areas such as the infected and necrotic zones. (author)

  13. Electron absorbed fractions of energy and S-values in an adult human skeleton based on {mu}CT images of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, R; Cassola, V F; Khoury, H J; De O Lira, C A B [Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife (Brazil); Richardson, R B [Radiation Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Vieira, J W [Federal Institute of Education, Science and Technology of Pernambuco, Recife (Brazil); Brown, K Robson, E-mail: rkramer@uol.com.br [Imaging Laboratory, Department of Archaeology and Anthropology, University of Bristol, Bristol (United Kingdom)

    2011-03-21

    When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on {mu}CT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 {mu}m thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters {sup 14}C, {sup 59}Fe, {sup 131}I, {sup 89}Sr, {sup 32}P and {sup 90}Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 {mu}m endosteum and the previously recommended 10 {mu}m endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by {approx}20% when the beta emitters are in marrow.

  14. Effect of single and fractionated x-irradiation on maze learning ability of mice

    International Nuclear Information System (INIS)

    Aoyama, Takashi; Norimura, Toshiyuki; Nakamura, Takeshi; Yoshikawa, Isao

    1976-01-01

    Fifty-six-day-old male ddk mice at the starting of the investigation were used as subjects through the experiment for 64 weeks. After 15 days' preliminary training, and 16 times of weekly trial training using complete maze, 15 mice received a single 224 rads of x-rays (S group), another 15 mice received two 112 rads spaced two weeks apart (F group) and another 15 mice were sham-irradiated (Control group). Then those mice were tested on the multiple T-maze with nine-choice points and change of performance was observed in terms of errorchoices by giving one test trial a week. We introduced the concept of ''confusional trials'' as an index for surmising to what extent mice failed to exhibit good maze learning habits. In the results, the F group showed significantly worse performance than the two other groups at early stages, opposite to it the S group exhibited the same, but at late stages after irradiation. The worse performance of F group should be considered to be due to the psychological after-effect to fractionated irradiation and that for S group could be assumed to be due to the acceleration of aging by the irradiation. (auth.)

  15. On kinetic study of blood cells and bone marrow under fractionated irradiation

    International Nuclear Information System (INIS)

    Teterina, V.I.

    1977-01-01

    To study the changes in the cellular composition of bone marrow during irradiation experiments on the guinea pigs have been carried out. Animals were subjected to fractionated irradiation; daily dose of 12 rad, total doses of 250, 500, 750, 1000 and 1500 rad, total duration of radiation of 1,2,3,4 and 6 monts. Experiments have shown that with small levels of total doses of the ionizing radiation haemopoiesis in the bone marrow reached its maximum. This led to suppression of anaemia and profound leukaemia in the peripheral blood. With the increase of total doses phase of insufficient compensation of harmful effects of radiation has been reached, which with continuing radiation may lead to the exhaustion of reserve possibilities of bone marrow and to the development of pancytopenia

  16. Food Preservation by Irradiation. Vol. II. Proceedings of an International Symposium on Food Preservation by Irradiation

    International Nuclear Information System (INIS)

    1978-01-01

    In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method of food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction of food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution of which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion of information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness studies

  17. Food Preservation by Irradiation. Vol. I. Proceedings of an International Symposium on Food Preservation by Irradiation

    International Nuclear Information System (INIS)

    1978-01-01

    In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method o f food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction o f food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution o f which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion o f information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness

  18. Changes in tumor oxygenation during a combined treatment with fractionated irradiation and hyperthermia: an experimental study.

    Science.gov (United States)

    Zywietz, F; Reeker, W; Kochs, E

    1997-01-01

    To determine the influence of adjuvant hyperthermia on the oxygenation status of fractionated irradiated tumors. Oxygen partial pressure (pO2) in rat rhabdomyosarcomas (R1H) was measured sequentially at weekly intervals during a fractionated irradiation with 60Co-gamma-rays (60 Gy/20f/4 weeks) in combination with local hyperthermia (8 f(HT) at 43 degrees C, 1 h/4 weeks). Tumors were heated twice weekly with a 2450 MHz microwave device at 43 degrees C, 1 h starting 10 min after irradiation. The pO2 measurements (pO2-histograph, Eppendorf, Germany) were performed in anesthetized animals during mechanical ventilation and in hemodynamic steady state. All tumor pO2 measurements were correlated to measurements of the arterial oxygen partial pressure (paO2) determined by a blood gas analyzer. The oxygenation status of R1H tumors decreased continuously from the start of the combined treatment, with increasing radiation dose and number of heat fractions. In untreated controls a median tumor pO2 of 23 +/- 2 mmHg (mean +/- SEM) was measured. Tumor pO2 decreased to 11 +/- 2 mmHg after 30 Gy + 4 HT (2 weeks), and to 6 +/- 2 mmHg after 60 Gy + 8HT (4 weeks). The increase in the frequency of pO2-values below 5 mmHg and the decrease in the range of the pO2 histograms [delta p(10/90)] further indicated that tumor hypoxia increased relatively rapidly from the start of combined treatment. After 60 Gy + 8HT 48 +/- 5% (mean +/- SEM) of the pO2-values recorded were below 5 mmHg. These findings suggest that adjuvant hyperthermia to radiotherapy induces greater changes in tumor oxygenation than radiation alone [cf. (39)]. This might be of importance for the temporary application of hyperthermia in the course of a conventional radiation treatment.

  19. Cytogenetic studies on recipients of allogeneic bone marrow transplants after fractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, N; Goedde-Salz, E; Loeffler, H [Christian-Albrechts-Univ., Kiel (Germany, F.R.)

    1985-06-01

    Cytogenetic findings from the bone marrow (BM) and the peripheral blood (PB) of nine consecutive patients after allogeneic bone marrow transplantation (BMT) for acute or chronic myelogenous leukaemia are reported. After a conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (TBI) given in five or six fractions of 2 Gy, persistence of host cells was detected in four out of seven cases with permanent engraftment. While one of these patients relapsed 4 months after host cells had been found in BM and PB, the other patients stayed relapse-free 124, 257 and 347 d after grafting. Before transplantation, the leukaemic cells in all three cases carried unique cytogenetic abnormalities giving the opportunity to distinguish the leukaemic population from chromosomally non-aberrant cells thought to represent residual normal host cells. As the persisting host cells after BMT lacked any cytogenetic abnormalities, it is suggested that they were members of residual normal clones not involved in the leukaemic process.

  20. Volumetrical and morphological responses of human laryngeal squamous cell carcinoma xenografts treated with fractionated irradiation

    International Nuclear Information System (INIS)

    Hoogenhout, J.; Gasteren, H. van; Jerusalem, C.R.; Kal, H.B.

    1988-01-01

    Xenografts of both primary human laryngeal squamous cell carcinoma and its metastases were irradiated with five daily fractions of 5.0 Gy. Tumor volume changes, morphology, mitotic index and mitotic figures were studied. Primary xenografts disappeared within 17±3 days. Grafts of metastases showed complete regression within 26±5 days, or regrowth after a delay period. Mitotic activity was higher in the grafts of metastases. The number of mitotic figures decreased and ceased within 14 days in the primary tumor, while some were still occasionally noted in the grafts of metastases. Telophase stages were practically absent after the first fraction. This study suggests that the response of metastases to radiation therapy is lower than the response of the primary tumor. (orig.) [de

  1. Cytogenetic studies on recipients of allogeneic bone marrow transplants after fractionated total body irradiation

    International Nuclear Information System (INIS)

    Schmitz, N.; Goedde-Salz, E.; Loeffler, H.

    1985-01-01

    Cytogenetic findings from the bone marrow (BM) and the peripheral blood (PB) of nine consecutive patients after allogeneic bone marrow transplantation (BMT) for acute or chronic myelogenous leukaemia are reported. After a conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (TBI) given in five or six fractions of 2 Gy, persistence of host cells was detected in four out of seven cases with permanent engraftment. While one of these patients relapsed 4 months after host cells had been found in BM and PB, the other patients stayed relapse-free 124, 257 and 347 d after grafting. Before transplantation, the leukaemic cells in all three cases carried unique cytogenetic abnormalities giving the opportunity to distinguish the leukaemic population from chromosomally non-aberrant cells thought to represent residual normal host cells. As the persisting host cells after BMT lacked any cytogenetic abnormalities, it is suggested that they were members of residual normal clones not involved in the leukaemic process. (author)

  2. Dose rate and dose fractionation studies in total body irradiation of dogs

    International Nuclear Information System (INIS)

    Kolb, H.J.; Netzel, B.; Schaffer, E.; Kolb, H.

    1979-01-01

    Total body irradiation (TBI) with 800-900 rads and allogeneic bone marrow transplantation according to the regimen designated by the Seattle group has induced remissions in patients with otherwise refractory acute leukemias. Relapse of leukemia after bone marrow transplantation remains the major problem, when the Seattle set up of two opposing 60 Co-sources and a low dose rate is used in TBI. Studies in dogs with TBI at various dose rates confirmed observations in mice that gastrointestinal toxicity is unlike toxicity against hemopoietic stem cells and possibly also leukemic stem cells depending on the dose rate. However, following very high single doses (2400 R) and marrow infusion acute gastrointestinal toxicity was not prevented by the lowest dose rate studied (0.5 R/min). Fractionated TBI with fractions of 600 R in addition to 1200 R (1000 rads) permitted the application of total doses up to 300 R followed by marrow infusion without irreversible toxicity. 26 dogs given 2400-3000 R have been observed for presently up to 2 years with regard to delayed radiation toxicity. This toxicity was mild in dogs given single doses at a low dose rate or fractionated TBI. Fractionated TBI is presently evaluated with allogeneic transplants in the dog before being applied to leukemic patients

  3. Total body irradiation in bone marrow transplantation: the influence of fractionation and delay of marrow infusion

    International Nuclear Information System (INIS)

    Lichter, A.S.; Tracy, D.; Lam, W.C.; Order, S.E.

    1980-01-01

    Bone marrow transplantation (BMT) after total body irradiation (TBI) and cyclophosphamide is being employed increasingly in the therapy of end stage leukemia. Interstitial pneumonitis (IP) represents a major acute toxicity after allogeneic transplantation. A more rapid reconstitution of lymphoid organs and bone marrow post transplant may result in increased immune competence and hence fewer opportunistic pulmonary infections and IP. By delaying the infusion of marrow to 72 hr after TBI (1250 rad at 7.5 rad/min) instead of the customary 24 hr, we can demonstrate an increase in initial repopulation of thymus, spleen and bone marrow, with syngeneic transplants in Lewis rats. Interstitial pneumonitis may also be caused, in part, by the pulmonary toxicity of large single exposures of TBI. Clinical and laboratory data suggest that fractionated TBI may be less toxic to the lung. When fractionated TBI (625 rad x 2, 7.5 rad/min) is compared to single dose TBI (1250 rad, 7.5 rad/min), and increased initial repopulation of lymphoid organs is observed when fractionated therapy is employed. Delay in marrow infusion and fractionation of TBI exposure may have clinical advantages in patients who receive BMT

  4. International standardization of instruments for neutron irradiation tests

    International Nuclear Information System (INIS)

    Tanimoto, Masataka; Shibata, Akira; Nakamura, Jinichi; Tsuchiya, Kunihiko; Cho, M.; Lee, C.; Park, S.; Choo, K.

    2012-01-01

    The JMTR in JAEA and HANARO in KAERI are the foremost testing/research reactors in the world and these are expected to contribute to many nuclear fields. As a part of instrument development in irradiation field, information exchange of instruments started from 2010 under the cooperation agreements between KAERI and JAEA. The instruments developed in JMTR and HANARO are introduced and cooperation experiments as future plan are discussed for international standardization. (author)

  5. Development of standardized methods to verify absorbed dose of irradiated fresh and dried fruits, tree nuts in trade

    International Nuclear Information System (INIS)

    Siddiqui, A.K.; Amin, M.R.; Chowdhury, N.A.; Begum, F.; Mollah, A.S.; Mollah, R.A.; Chowdhury, A.H.

    2001-01-01

    Investigations were carried out on standardization of desired process control parameters such as dose distribution in trade containers, container standardization and development of 'label' dosimeters. A prototype 'label' dose indicators Sterins for threshold doses of 125 Gy and 300 Gy was studied. Dose distribution was studied using fresh fruits and tree nuts in trade and standardized containers with varying product densities. The distribution of absorbed doses was measured by Fricke, Gammachrome YR, clear Polymethylmethacrylate (PMMA), EthanolChlorobenzene (ECB) and Sterin 300. These values are given as Dmax/Dmin ratios in relation to product bulk densities. It was observed that bulk densities varied greatly among different products depending on the types of fruits, containers and pattern of loading which also affected dose distribution. Dmax/Dmin obtained by proper dose mapping could be kept low by arranging proper irradiation conditions which ensured uniform dose distribution. Prototype 'label' dose indicators like Sterins and clear PMMA were used for dose mapping along with the standard primary and secondary dosimeters. Sterins and clear PMMA were also studied for their dosimetric properties, particularly for use in label dosimetry. Sterins 125 and 300 evaluated visually showed their integrity at their threshold doses. The word NOT on Sterin 125 eclipsed after 115 Gy and on Sterin 300 after 270 Gy dose. Clear PMMA samples of 410 mm thickness irradiated at 200-1000 Gy showed linear response and had postirradiation stability for over a month storage at normal temperatures (21-35 deg. C) and humidities. These could be investigated further for developing as 'label' dosimeters in insect control quarantine treatment. Other low dose indicators studied such as coloured perspex, dye solutions were not found useful at quarantine dose levels. Further investigations are required for developing a 'label' dosimeter for commercial use. (author)

  6. Kinetics of EGFR expression during fractionated irradiation varies between different human squamous cell carcinoma lines in nude mice

    International Nuclear Information System (INIS)

    Eicheler, Wolfgang; Krause, Mechthild; Hessel, Franziska; Zips, Daniel; Baumann, Michael

    2005-01-01

    Background and purpose: Preclinical and clinical data indicate that high pretherapeutic EGFR expression is associated with poor local tumour control, possibly caused by a high repopulation rate of clonogenic cells during radiotherapy in these tumours. Previous data reported from our laboratory showed a correlation between EGFR expression and acceleration of repopulation in poorly differentiated FaDu human squamous cell carcinoma (SCC) during fractionated irradiation. To test whether this is a general phenomenon, two further SCC were investigated in the present study. Patients and methods: GL and UT-SCC-14, two moderately well differentiated and keratinising hSCC, were grown as xenografts in nude mice. Functional data on the repopulation kinetics during fractionated irradiation for these tumour models have been previously determined. The expression of EGFR during fractionation was analysed by immunohistochemistry. Endpoints were the membrane-staining score and the proportion of EGFR-positive cells (EGFR labelling index). Results: Different kinetics of EGFR expression during fractionated RT were found. In UT-SCC-14, EGFR staining score and labelling index increased significantly during radiotherapy. In GL SCC, the EGFR expression was unchanged. Both tumours are characterized by a small but significant repopulation rate during radiotherapy. Conclusions: The expression of EGFR may change significantly during fractionated irradiation. No clear correlation between EGFR expression and the repopulation kinetics of clonogenic tumour cells during fractionated irradiation was found. The changes in EGFR expression during irradiation warrant further investigation on their prognostic implications and on their importance for therapeutic interventions

  7. Skin toxicity during hypo fractionated breast irradiation in patient with early breast cancer

    International Nuclear Information System (INIS)

    Petrova, Deva; Smichkoska, Snezhana

    2013-01-01

    Radiotherapy is an important component in the treatment of breast cancer. (1) Many women with an early stage of breast cancer are candidates for a breast conservation therapy, which combines both conservative surgery and radiotherapy. (2) According to the data from some series, an estimated 90% of the patients treated with radiotherapy for breast cancer will develop a degree of radiation-induced dermatitis. (3) The severity of the skin reactions during and following the breast irradiation is influenced by both treatment-related and patient-related factors. The treatment - related factors include the fraction size (the dose delivered with each treatment), the total dose delivered, the volume of tissue treated, the type of radiation (4) and the addition of chemotherapy. (5) The patient-related factors include breast size, smoking, axillary lymphocele drainage before treatment, age, and infection of the surgical wound. (6) A hypo fractionation radiotherapy is alternative for a standard fractionation radiotherapy for women with early stage of breast cancer after conservative surgery. The aim of the study was to analyse the acute skin reactions during a hypo fractionated radiotherapy in patients with early breast cancer at our institution. Materials and methods: Twenty patients with early stage of breast cancer (Stadium I and II) and conservative surgery (quadrantectomy of breast with ipsilateral axillary dissection) were analysed. The patients were treated with 6MV x rays on LINAC, using tangential fields with 2.65Gy per fraction and the total dose prescribed to target volume was 42,4 Gy. These patients were observed for acute skin toxicity during the second week and at the end of the treatment. We evaluated dryness, epilation, pigmentation, changes and eritema, dry desquamation (clinically characterized by scaling and pruritus) and moist desquamation (characterized by serious oozing and exposure of the dermis). By using the radiation therapy oncology group’s (RTOG

  8. The effect of fractional CO2 laser irradiation on remineralization of enamel white spot lesions.

    Science.gov (United States)

    Poosti, Maryam; Ahrari, Farzaneh; Moosavi, Horieh; Najjaran, Hoda

    2014-07-01

    This study investigated the combined effect of fractional CO(2) laser irradiation and fluoride on treatment of enamel caries. Sixty intact premolars were randomly assigned into four groups and then stored in a demineralizing solution to induce white spot lesions. Tooth color was determined at baseline (T1) and after demineralization (T2). Afterwards, the teeth in group 1 remained untreated (control), while group 2 was exposed to an acidulated phosphate fluoride (APF) gel for 4 min. In groups 3 and 4, a fractional CO(2) laser was applied (10 mJ, 200 Hz, 10 s) either before (group 3) or through (group 4) the APF gel. The teeth were then immersed in artificial saliva for 90 days while subjected to daily fluoride mouthrinse and weekly brushing. Color examinations were repeated after topical fluoride application (T3) and 90 days later (T4). Finally, the teeth were sectioned, and microhardness was measured at the enamel surface and at 30 and 60 μ from the surface. In both lased groups, the color change between T1 and T4 stages (∆E(T1-T4)) was significantly lower than those of the other groups (p Laser irradiation followed by fluoride application (group 3) caused a significant increase in surface microhardness compared to APF alone and control groups (p laser before fluoride therapy is suggested for recovering the color and rehardening of demineralized enamel.

  9. In vivo induction of apoptosis in human lymphocytes by therapeutic fractionated total body irradiation

    International Nuclear Information System (INIS)

    Delic, J.; Magdelenat, H.; Barbaroux, C.; Chaillet, M.-P.; Dubray, B.; Fourquet, A.; Cosset, J.-M.; Gluckman, E.; Girinsky, T.

    1995-01-01

    Ionizing radiations have been reported as an in vitro apoptosis initiating stimulus in human lymphocytes. As the cytotoxicity of ionizing radiations and chemotherapeutic agents appears to be dependent on the efficacy of cell death induction, the manipulation of apoptosis initiation might be used as a means to suppress some pathological process. In the present study the in vivo induction of γ-ray mediated programmed cell death in humans is reported. The in vivo induction of apoptosis in peripheral blood lymphocytes (PBL) by ionizing radiations was investigated in 33 patients after each of two sessions (2 Gy and 4 Gy) of fractionated total body irradiation (FTBI) as part of their conditioning regimen before bone marrow transplantation. PBL committed to apoptosis were scored before irradiation (S1), 4 h (S2) and 24 h after 2 Gy (S3, 14-17 h after the second 2 Gy fraction). Nuclear morphology and chromatin-DNA were analysed by fluorescence microscopy immediately after blood sample withdrawal (I) and after 24 h in cell culture medium (II). (author)

  10. Combined effect of carcinogenic n-nitrosodimethylamine precursors and fractioned γ-irradiation on tumor development in rats

    International Nuclear Information System (INIS)

    Galenko, P.M.; Nedopitanskaya, N.N.

    1996-01-01

    The influence of combined action of N-nitrosodimethylamine (NDMA) and fractioned γ-irradiation on tumor development in rats was investigated. Both the tumor frequency and tumor plurality coefficient have been studied for two types of treatment: precursors of NDMA (amidopyrine and/or sodium nitrite (SN)) alone and the combination 'precursors plus radiation'. Tumor frequency decreased by about 11% after combination of γ-irradiation and precursors in comparison with precursors alone. Nevertheless, treatment with SN and γ-irradiation did not change tumor frequency in comparison with SN alone. Irradiation of rats treated with precursors led to an increased tumor plurality coefficient

  11. Test of equal effect per fraction and estimation of initial clonogen number in microcolony assays of survival after fractionated irradiation

    International Nuclear Information System (INIS)

    Thames, H.D.; Withers, H.R.

    1980-01-01

    In the use of multifraction microcolony assays to infer the low-dose response of in situ renewal systems such as intestinal crypts, the assumption of equal effect per dose fraction is required. Moreover, the construction of a cell-survival curve requires knowledge of the initial count of cells capable of repopulating each renewal structure. We describe a method of designing fractionation protocols which provides a regression estimate of the initial number of clonogens per renewal structure and a test of the hypothesis of equal effect per fraction. The essential factor in the experimental design is the use of common dose fractions (use of the same dose per fraction in series with different numbers of fractions). Applications of the method to data for which the assumption of equal effect per fraction holds (four-hour fractionation interval murine testis study) and does not hold (one-hour fractionation interval murine jejunal crypt study) are presented. (author)

  12. Early neuro-vegetative responses to head irradiation of the rabbit at mean absorbed doses of 1000 and 150 rads

    International Nuclear Information System (INIS)

    Dufour, Raymond.

    1977-10-01

    Head irradiation was studied in order to back up a previous assumption on the kinetics of vegetative responses to whole-body exposure: the earliest response might have a central origin and explain the slight increase of blood pressure, tachycardia, hyperthermia and hyperventilation. Following head exposure at a mean absorbed dose of 1000 rads, blood pressure increased on the 15 th min, reaching 0.8 - 1 cm Hg on the 30th min and during 7 - 8 hours. The increase of heart rate occured as early and was about 40% and lasted for 24 hours. Body temperature increased as early as the end of exposure, was highest within 2 - 2.30 hours and decreased on the 6th hour. Arterial blood showed a respiratory alkalosis on the 1st hour, lasting after the 6th hour and disappeared within 24 hours. At a dose of 150 rads, the changes were lasting but of lower importance and duration. The results show that early changes following whole-body exposure also occur after head exposure and are magnified. The kinetics involved are discussed [fr

  13. Determination of absorbed dose in crystalline and thyroid gland with irradiation protocols applied in orthopantomography equipment for dental examination

    International Nuclear Information System (INIS)

    Munoz A, A. A.; Ramirez A, L. M.; Sosa A, M. A.; Azorin V, J. C.; Vallejo H, M. A.

    2016-10-01

    Ionizing radiations are very useful in the medical field for the diagnostic use of different pathologies. Currently there are different technologies for diagnostic imaging using conventional X-ray, computed tomography, mammography, angiography, dental panoramic X-ray, among others. However, it should be noted that exposure to radiation in this type of diagnostic tests has increased considerably in recent years, because radiological examinations are not always carried out according to the actual clinical needs of each patient, increasing the risk to develop cancer. In this paper, the absorbed dose in the lens and thyroid gland was measured with the help of TLD-100 dosimeters located in a PMMA phantom adapted for orthopantomography (dental panoramic X-ray) equipment in 5 hospitals; using the parameters pre-configured for normal adult for irradiation. A Harshaw 3500 equipment was used to read the dosimeters, obtaining a value of 1.324 ± Sd 0.01 mGy for crystalline and 1.044 ± Sd 0.03 mGy values which are intended to be validated under other conditions and protocols. (Author)

  14. Effects of low-dose continuously fractionated X-ray irradiation on murine peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Xie Yi; Zhang Hong; Dang Bingrong; Hao Jifang; Guo Hongyun; Wang Xiaohu

    2007-01-01

    For estimating biological risks from low doses continual irradiation, we investigated the effects of exposure to continuously fractionated X-rays on murine immune system. The BALB/c mice were irradiated with 0.07Gy at the first day and 0.08 Gy/d in the following 12 days at a dose rate of 0.2 Gy/min. The peripheral blood lymphocyte cycle and death were determined by flow cytometry at the cumulative doses of 0, 0.07, 0.23, 0.39, 0.55, 0.71, 0.87 and 1.03 Gy respectively. The results showed that the cycle of peripheral blood lymphocyte was arrested in G 0 /G 1 at cumulative doses of 0.07, 0.23, 0.71 and 0.87 Gy, and in G 2 /M at cumulative doses of 0.39 and 1.03 Gy; the percentage of death of peripheral blood lymphocyte was ascended with dose increasing, and reached the death peak at cumulative doses of 0.71 Gy. The results suggested that low doses continual X-rays total-body irradiated could result in changes of cellular cycle and death, and some damages to immunocytes, which accorded to linear square model. (authors)

  15. Radiogenic responses of normal cells induced by fractionated irradiation -a simulation study. Pt. 2. Late responses

    International Nuclear Information System (INIS)

    Duechting, W.; Ulmer, W.; Ginsberg, T.; Kikhounga-N'Got, O.; Saile, C.

    1995-01-01

    Based on controlled theory, a computed simulation model has been constructed which describes the time course of slowly responding normal cells after irradiation exposure. Subsequently, different clinical irradiation schemes are compared in regard to their delayed radiogenic responses referred to as late effects in radiological terminology. A cybernetic model of a paraenchymal tissue consisting of dominantly resting functional cells has been developed and transferred into a computer model. The radiation effects are considered by characteristic cell parameters as well as by the linear-quadratic model. Three kinds of tissue (brain and lung parenchym of the mouse, liver parenchym of rat) have been irradiated in the model according to standard-, super-, hyperfractionation and a single high dose per week. The simulation studies indicate that the late reaction of brain parenchym to hyperfractionation (3 x 1.5 Gy per day) and of lung parenchym tissue with regard to all fractionation schemes applied is particularly severe. The behavior of liver parenchym is not unique. A comparison of the simulation results basing to the survival of cell numbers with clinical experience and practice shows that the clinical reality can qualitatively be represented by the model. This opens the door for connecting side effects to normal tissue with the corresponding tumor efficacy (discussed in previous papers). The model is open to further refinement and to discussions referring to the phenomenon of late effects. (orig.) [de

  16. Effect of gamma background on the dose absorbed by human embryon and foetus

    International Nuclear Information System (INIS)

    Miloslavov, V.; Doncheva, B.

    1989-01-01

    A method is proposed for calculation of absorbed radiation dose in different stages of human foetus development under normal or increased gamma background. On the base of ICRP-data for critical organ's mass (foetus, placenta, blood, uterus) a formula is given for absorbed dose evaluation of gonads. It is concluded that increased gamma background is insignificant compared to internal irradiation from absorbed radionuclides

  17. Experimental study on the ionizing radiation field in absorbers irradiated by the 0.8 GeV and 1.2 GeV electrons

    International Nuclear Information System (INIS)

    Ambrosimov, V.K.; Kalmykov, N.N.; Kovalenko, G.D.

    1987-01-01

    The measurement results of spatial distribution of aluminium detector energy release and radioactivity in absorbers irradiated by 0.8 and 1.2 GeV electrons are given. Absorbers are made of aluminium, iron and lead, 30x30 cm size across the thickness is about 18 radiation length units. Thermoluminescence dosimeters LiF and radiochromium film dosimeters have been used to measure energy release. Induced activity of 18 F and 24 Na nuclides is determined in aluminium detectors. The experimental data are compared with the results of calculation carried out by the Monte-Carlo method

  18. Preparation and characterization of super absorbent polymer from sugarcane bagasse

    International Nuclear Information System (INIS)

    Wiwien Andriyanti; Suyanti; Ngasifudin

    2012-01-01

    Sugarcane bagasse is a source of biomass which large enough numbers and has not been fully exploited. At this time has developed a super absorbent polymer material of sugarcane bagasse that can absorb water up to several times of its own weight and keep this water. Super absorbent polymers can be used as a soil conditioner that can be used as an absorber and storage of ground water, the giver of nutrients for plants, and can improve soil properties. The purpose of this study is to make and characterization of super absorbent polymer (PCS) from sugarcane bagasse. Preparation of super absorbent polymers (PCS) has been done by grafting method using ionizing radiation from Electron Beam Engineering (MBE) 350 mA keV/10. Irradiation process carried out with a dose variation of 20, 35, and 50 kGy. Increasing doses of radiation will increase the percentage fraction of transplantation (grafting) and the fraction of water absorption ability (swelling ratio). (author)

  19. Simvastatin Ameliorates Radiation Enteropathy Development After Localized, Fractionated Irradiation by a Protein C-Independent Mechanism

    International Nuclear Information System (INIS)

    Wang Junru; Boerma, Marjan; Fu Qiang; Kulkarni, Ashwini; Fink, Louis M.; Hauer-Jensen, Martin

    2007-01-01

    Purpose: Microvascular injury plays a key role in normal tissue radiation responses. Statins, in addition to their lipid-lowering effects, have vasculoprotective properties that may counteract some effects of radiation on normal tissues. We examined whether administration of simvastatin ameliorates intestinal radiation injury, and whether the effect depends on protein C activation. Methods and Materials: Rats received localized, fractionated small bowel irradiation. The animals were fed either regular chow or chow containing simvastatin from 2 weeks before irradiation until termination of the experiment. Groups of rats were euthanized at 2 weeks and 26 weeks for assessment of early and delayed radiation injury by quantitative histology, morphometry, and quantitative immunohistochemistry. Dependency on protein C activation was examined in thrombomodulin (TM) mutant mice with deficient ability to activate protein C. Results: Simvastatin administration was associated with lower radiation injury scores (p < 0.0001), improved mucosal preservation (p = 0.0009), and reduced thickening of the intestinal wall and subserosa (p = 0.008 and p = 0.004), neutrophil infiltration (p = 0.04), and accumulation of collagen I (p = 0.0003). The effect of simvastatin was consistently more pronounced for delayed than for early injury. Surprisingly, simvastatin reduced intestinal radiation injury in TM mutant mice, indicating that the enteroprotective effect of simvastatin after localized irradiation is unrelated to protein C activation. Conclusions: Simvastatin ameliorates the intestinal radiation response. The radioprotective effect of simvastatin after localized small bowel irradiation does not appear to be related to protein C activation. Statins should undergo clinical testing as a strategy to minimize side effects of radiation on the intestine and other normal tissues

  20. A theoretical study on the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells

    International Nuclear Information System (INIS)

    Wen Xiaoqiong; Li Qiang; Zhou Guangming; Li Wenjian; Wang Jufang; Wei Zengquan

    2001-01-01

    In order to provide theoretical basis for the homogeneity request of heavy-ion irradiation field, the most important design parameter of the heavy-ion radiotherapy facility planned in IMP (Institute of Modern Physics), the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells was investigated theoretically. A formula for survival fraction of cells irradiated by the un-uniform heavy-ion irradiation field was deduced to estimate the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells. The results show that the survival fraction of cells irradiation by the un-uniform irradiation field is larger than that of cells irradiated by the uniform irradiation field, and the survival fraction of cells increases as the homogeneity of heavy-ion irradiation field decreasing. Practically, the heavy-ion irradiation field can be treated as uniform irradiation field when its homogeneity is better than 95%. According to these results, design request for the homogeneity of heavy-ion irradiation field should be better than 95%. The present results also show that the agreement of homogeneity of heavy-ion irradiation field must be checked while comparing the survival fraction curves obtained by different laboratory

  1. Fractionated total lymphoid irradiation as preparative immunosuppression in high risk renal transplantation

    International Nuclear Information System (INIS)

    Najarian, J.S.; Ferguson, R.M.; Sutherland, D.E.; Slavin, S.; Kim, T.; Kersey, J.; Simmons, R.L.

    1982-01-01

    Twenty-two patients at high risk to reject renal allografts have been treated with fractionated total lymphoid irradiation (FTLI) prior to transplantation of primary (2), secondary (16) or tertiary (4) renal allografts. All patients undergoing retransplantation had rapidly rejected previous grafts. At 24 months following transplantation, 72% of grafts were functioning in the TLI group compared with a 38% graft function in an historical control group of recipients receiving secondary or tertiary grafts and treated with conventional immunosuppression. Important variables in determining success of transplantation following fractionated TLI include the dose of TLI, the interval from radiation to transplantation, and maintenance post-transplant immunosuppressive therapy. Optimal results were achieved with 2500 rads delivered in 100 rad fractions followed by transplantation within two weeks, and a tapering prednisone schedule and maintenance azathioprine post-transplantation. Seventeen patients had significant complications of the radiation treatment and there was one death, prior to transplantation, associated with pneumonitis. In vitro assessment of immune function demonstrated marked peripheral T cell depletion and loss of in vitro responsiveness to mitogen and allogeneic stimulation following FTLI. The administration of donor bone marrow at the time of transplantation did not produce chimerism. The results suggest that when properly utilized FTLI can produce effective adjunctive immunosuppression for clinical transplantation

  2. Fractionated half body irradiation for palliation of multiple symptomatic bone metastases from solid tumors

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Kenji; Hayashi, Shinya; Sunagawa, Yoshimitsu; Sougawa, Mitsuharu; Nakazawa, Masanori; Yamashita, Takashi (Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital)

    1992-06-01

    This was a phase I-II nonrandomized study that explored the toxicity and response of fractionated half-body irradiation (F-HBI) in patients with multiple symptomatic osseous metastases. The patients had no premedication and received 10 Gy in 5 fractions with a dose rate of 15 cGy/min. At the Cancer Institute Hospital, 9 patients were treated by this technique (1 upper and lower F-HBI, 6 upper F-HBI, 2 lower F-HBI). All patients were female and had adenocarcinomas (8 breast and 1 lung). Adverse effects were myelosuppression, vomiting and partial alopecia. But hematologic toxicity was treated with blood transfusion or G-CSF. All toxicity was transient, and no pneumonitis nor radiation-related deaths occurred. When given as palliation, F-HBI was found to relieve pain in 80% of the patients. In 10% of the patients the pain relief was complete. The mean time to achieve pain relief in responders after F-HBI was 9 days. The pain relief was long-lasting and continued without need of reirradiation for 40% of the remaining patient's life. This treatment modality appears to be well tolerated and effective in patients with multiple symptomatic osseous metastases. The optimal indications, dose and fractionation for F-HBI should be further explored in randomized trials. (author).

  3. Enhancing hair follicle regeneration by nonablative fractional laser: Assessment of irradiation parameters and tissue response.

    Science.gov (United States)

    Wu, Yueh-Feng; Wang, Shiou-Han; Wu, Pei-Shan; Fan, Sabrina Mai-Yi; Chiu, Hsien-Yi; Tsai, Tsung-Hua; Lin, Sung-Jan

    2015-04-01

    Identification of methods to enhance anagen entry can be helpful for alopecia. Recently, nonablative laser has been proposed as a potential treatment for alopecia. However, how the laser parameters affect stem cell activity, hair cycles and the associated side effects have not been well characterized. Here we examine the effects of irradiation parameters of 1,550-nm fractional laser on hair cycles. The dorsal skin of eight-week-old female C57BL/6 mice with hair follicles in synchronized telogen was shaved and irradiated with a 1,550-nm fractional erbium-glass laser (Fraxel RE:STORE (SR1500) Laser System, Solta Medical, U.S.A.) with varied beam energies (5-35 mJ) and beam densities (500-3500 microthermal zones/cm(2) ). The cutaneous changes were evaluated both grossly and histologically. Hair follicle stem cell activity was detected by BrdU incorporation and changes in gene expression were quantified by real-time PCR. Direct thermal injury to hair follicles could be observed early after irradiation, especially at higher beam energy. Anagen induction in the irradiated skin showed an all-or-non change. Anagen induction and ulcer formation were affected by the combination of beam energy and density. The lowest beam energy of 5 mJ failed to promote anagen entry at all beam densities tested. As beam energy increased from 10 mJ to 35 mJ, we found a decreasing trend of beam density that could induce anagen entry within 7-9 days with activation of hair follicle stem cells. Beam density above the pro-regeneration density could lead to ulcers and scarring followed by anagen entry in adjacent skin. Analysis of inflammatory cytokines, including TNF-α, IL-1β, and IL-6, revealed that transient moderate inflammation was associated with anagen induction and intense prolonged inflammation preceded ulcer formation. To avoid side effects of hair follicle injury and scarring, appropriate combination of beam energy and density is required. Parameters outside the therapeutic

  4. Kinetics and capacity of repair of sublethal damage in mouse lip mucosa during fractionated irradiations

    International Nuclear Information System (INIS)

    Ang, K.K.; Xu, F.X.; Landuyt, W.; van der Schueren, E.

    1985-01-01

    The kinetics and capacity of repair of sublethal damage in mouse lip mucosa have been investigated. To assess the rate of repair 2 and 5 irradiations have been given with intervals ranging from 1 to 24 hours. It was found that the sublethal damage induced by a dose of approximately 10 Gy was fully recovered in approximately 4 hr. After a dose of 5-6 Gy, cellular repair was completed within 3 hr. The half time of repair (T1/2) was estimated to be approximately 72 min for 10 Gy and approximately 54 min for 5-6 Gy. Although these results suggest that the rate of repair is dependent on the fraction size, the possible influence of the amount of repair of sublethal radiation damage with the various fraction sizes used can not be ruled out. To evaluate the capacity of repair, a single dose, 2, 4 and 10 fractions have been given in a maximal overall time of 3 days in order to minimize the influence of repopulation. The slope of the isoeffective curve was 0.32 and the alpha/beta ratio was 8.5 Gy. This indicates that the capacity of cellular repair of lip mucosa is similar to those of other rapidly proliferating tissues but smaller than those of late responding tissues. The results of the present and other studies demonstrate that there are considerable differences in the repair characteristics between acutely and late responding tissues. These features have to be dealt with when fractionation schedules are markedly altered

  5. Considerations on absorbed dose estimates based on different β-dose point kernels in internal dosimetry

    International Nuclear Information System (INIS)

    Uchida, Isao; Yamada, Yasuhiko; Yamashita, Takashi; Okigaki, Shigeyasu; Oyamada, Hiyoshimaru; Ito, Akira.

    1995-01-01

    In radiotherapy with radiopharmaceuticals, more accurate estimates of the three-dimensional (3-D) distribution of absorbed dose is important in specifying the activity to be administered to patients to deliver a prescribed absorbed dose to target volumes without exceeding the toxicity limit of normal tissues in the body. A calculation algorithm for the purpose has already been developed by the authors. An accurate 3-D distribution of absorbed dose based on the algorithm is given by convolution of the 3-D dose matrix for a unit cubic voxel containing unit cumulated activity, which is obtained by transforming a dose point kernel into a 3-D cubic dose matrix, with the 3-D cumulated activity distribution given by the same voxel size. However, beta-dose point kernels affecting accurate estimates of the 3-D absorbed dose distribution have been different among the investigators. The purpose of this study is to elucidate how different beta-dose point kernels in water influence on the estimates of the absorbed dose distribution due to the dose point kernel convolution method by the authors. Computer simulations were performed using the MIRD thyroid and lung phantoms under assumption of uniform activity distribution of 32 P. Using beta-dose point kernels derived from Monte Carlo simulations (EGS-4 or ACCEPT computer code), the differences among their point kernels gave little differences for the mean and maximum absorbed dose estimates for the MIRD phantoms used. In the estimates of mean and maximum absorbed doses calculated using different cubic voxel sizes (4x4x4 mm and 8x8x8 mm) for the MIRD thyroid phantom, the maximum absorbed doses for the 4x4x4 mm-voxel were estimated approximately 7% greater than the cases of the 8x8x8 mm-voxel. They were found in every beta-dose point kernel used in this study. On the other hand, the percentage difference of the mean absorbed doses in the both voxel sizes for each beta-dose point kernel was less than approximately 0.6%. (author)

  6. Haemopoiesis-enhancing effects of repeatedly administered carboxymethylglucan in mice exposed to fractionated irradiation

    International Nuclear Information System (INIS)

    Hofer, M.; Pospisil, M.; Pipalova, I.; Hola, J.

    1995-01-01

    Carboxymethylglucan (CMG), a water-soluble glucan derivative, enhanced the number of granulocytes in the peripheral blood as well as other indices of haemopoietic recovery (total cellularity and the number of granulocyte-macrophage progenitor cells in femoral marrow, spleen weight) investigated after fractionated gamma-irradiation of mice (five doses of 2 Gy each, or three, four and five doses of 3 Gy each given at 24 hours' intervals). An increased liver weight and a more pronounced anaemia found in the CMG-treated mice suggested that also inflammatory side effects were evoked by repeated CMG administration. On the other hand, the development of tolerance, i.e., a decreased effectiveness of CMG treatment on repeated administration did not seem to play a major role under the experimental conditions studied because the protective effects of CMG increased with the increasing number of CMG injections. (author) 2 figs., 16 refs

  7. Total proteins and protein fractions levels in pregnant rats subjected to whole-body gamma irradiation

    International Nuclear Information System (INIS)

    Mansour, M.A.; Roushdy, H.M.; Mazhar, F.M.; Abu-Gabal, H.A.

    1986-01-01

    A total number of 180 mature rats (120 females and 60 males) weighing from 120-140 g were used to study the effect of two doses (2 and 4 Gy) whole-body gamma irradiation on the level of total protein and protein fractions in serum of pregnant rats during the period of organogenesis. It was found that the levels of total protein, albumin and gamma globulins significantly decreased according to the doses of exposure. The levels of alpha and beta globulins significantly increased more in the serum of rats exposed to 2 Gy than in rats exposed to 4 Gy. The level of A/G ratio significantly decreased more in the serum of rats exposed to 2Gy than in those exposed to 4 Gy

  8. Fractionated vs acute irradiation: the effects of treating adult boll weevils (Coleoptera: Curculionidae) at different ages

    International Nuclear Information System (INIS)

    Haynes, J.W.; Wright, J.E.; Mattix, E.

    1979-01-01

    When 6-7 days old mass-reared ebony boll weevils, Anthonomus grandis Boheman, were given 25 doses of γ-irradiation totaling 6625 rads, mortality was 14%-15% less 1 week later than when young weevils (1-2 day-old) were similarly treated. However, giving older weevils an acute dose of 6625 rads did not reduce mortality. Seven-day-old weevils receiving the acute treatment mated 10% more than weevils that were 3 days old at the time of treatment. Seven-day-old male weevils exposed to the fractionated treatment transferred sperm to 12% more females than 7-day-old males exposed to the acute treatment. (Auth.)

  9. Allogeneic bone marrow transplantation in adults after fractionated body irradiation and high dose cyclophosphamide

    International Nuclear Information System (INIS)

    Brinch, L.; Evensen, S.A.; Albrechtsen, D.; Egeland, T.; Solheim, B.G.; Rollag, H.; Naalsund, A.; Jacobsen, A.B.

    1991-01-01

    The authors present short and long-term results of allogeneic bone marrow transplantation after hyper-fractionated total body irradiation and high dose cyclophosphamide in ten patients treated for leukaemia during th period 1985-89. Three patients died from complications connected to the transplantation, while seven are living free from leukaemia 18 to 59 months after transplantation. Two patients need treatment for chronic graft versus host disease. Allogeneic bone marrow transplantation is expensive and risky. Close cooperation between clinicians and laboratory specialists is essential. The treatment increases long term survival and probably cures certain patients with leukaemia. Some of the patients will need treatment for chronic graft versus host disease and other late sequelae. 19 refs., 2 tabs

  10. SU-F-J-56: The Connection Between Cherenkov Light Emission and Radiation Absorbed Dose in Proton Irradiated Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Darafsheh, A; Kassaee, A; Finlay, J [University of Pennsylvania, Philadelphia, PA (United States); Taleei, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: Range verification in proton therapy is of great importance. Cherenkov light follows the photon and electron energy deposition in water phantom. The purpose of this study is to investigate the connection between Cherenkov light generation and radiation absorbed dose in a water phantom irradiated with proton beams. Methods: Monte Carlo simulation was performed by employing FLUKA Monte Carlo code to stochastically simulate radiation transport, ionizing radiation dose deposition, and Cherenkov radiation in water phantoms. The simulations were performed for proton beams with energies in the range 50–600 MeV to cover a wide range of proton energies. Results: The mechanism of Cherenkov light production depends on the initial energy of protons. For proton energy with 50–400 MeV energy that is below the threshold (∼483 MeV in water) for Cherenkov light production directly from incident protons, Cherenkov light is produced mainly from the secondary electrons liberated as a result of columbic interactions with the incident protons. For proton beams with energy above 500 MeV, in the initial depth that incident protons have higher energy than the Cherenkov light production threshold, the light has higher intensity. As the slowing down process results in lower energy protons in larger depths in the water phantom, there is a knee point in the Cherenkov light curve vs. depth due to switching the Cherenkov light production mechanism from primary protons to secondary electrons. At the end of the depth dose curve the Cherenkov light intensity does not follow the dose peak because of the lack of high energy protons to produce Cherenkov light either directly or through secondary electrons. Conclusion: In contrast to photon and electron beams, Cherenkov light generation induced by proton beams does not follow the proton energy deposition specially close to the end of the proton range near the Bragg peak.

  11. Proliferation and clonal survival of human lung cancer cells treated with fractionated irradiation in combination with paclitaxel

    International Nuclear Information System (INIS)

    Rijn, Johannes van; Berg, Jaap van den; Meijer, Otto W.M.

    1995-01-01

    Purpose: This study was performed to determine the effects of a continuous exposure to paclitaxel (taxol) in combination with fractionated irradiation on cell proliferation and survival. Methods and Materials: Human lung carcinoma cells (SW1573) were given a daily treatment with 3 Gy of x-rays during 5 days in the continuous presence of 5 nM taxol. The surviving fraction and the total number of cells were determined every 24 h before and immediately after irradiation. Results: Irradiation with 5 x 3 Gy and 5 nM taxol cause approximately the same inhibition of cell proliferation. In combination these treatments have an additional effect and the cell population increases no further after the first 24 h. Whereas the cells become more resistant to taxol after the first 24 h with a minimum survival of 42%, taxol progressively reduces the population of surviving cells in combination with x-rays when the number of fractions increases, up to 25-fold relative to irradiation alone. The enhancement effect of 5 nM taxol is likely to be attributed to an inhibition of the repopulation during fractionated irradiation and not to an increased radiosensitivity. Only after treatment with 10 or 100 nM taxol for 24 h, which is attended with a high cytotoxicity, is moderate radiosensitization observed. Conclusion: Taxol, continuously present at a low concentration with little cytotoxicity, causes a progressive reduction of the surviving cell population in combination with fractionated irradiation, mainly by an inhibition of the repopulation of surviving cells between the dose fractions

  12. First experiences with super fractionated skin irradiations using large afterloading molds

    International Nuclear Information System (INIS)

    Fritz, Peter; Hensley, Frank W.; Berns, Christiane; Schraube, Peter; Wannenmacher, Michael

    1996-01-01

    Purpose: Radiotherapy of cutaneous metastases of breast cancer requires large radiation fields and high doses. This report examines the effectiveness and sequelae of super fractionated irradiation of cutaneous metastases of breast cancer with afterloading molds on preirradiated and nonirradiated skin. Methods and Materials: A flexible reusable skin mold was developed for use with a pulsed (PDR) after loader. An array of 18 parallel catheters was sewn between two foam rubber slabs 5 mm in thickness to provide a defined constant distance to the skin. By selection of appropriate dwell positions, arbitrarily shaped skin areas can be irradiated up to a maximal field size of 17 x 23.5 cm 2 . Irradiations are performed with a nominal 37 GBq 192 Ir stepping source in pulses of 1 Gy/h at the skin surface. The dose distribution is geometrically optimized. The 80 and 50% dose levels lie 5 and 27 mm below the skin surface. Sixteen patients suffering from metastases at the thoracic wall were treated with 18 fields (78-798 cm 2 ) and total doses of 40-50 Gy applying two PDR split courses with a pause of 4-6 weeks. Eleven of the fields had been previously irradiated with external beam therapy to doses of 50-60 Gy at 7-22 months in advance. Results: For preirradiated fields (n = 10) the results were as follows: follow-up 4.5-28.5 months (median 17); local control (LC): 8 of 10; acute skin reactions: Grade 2 (moist desquamation) 2 of 10; intermediate/late skin reactions after minimum follow-up of 3 months: Grade 1 (atrophy/pigmentation): 2 of 10, Grade 2-3a (minimal/marked telangiectasia): 7 of 10, Grade 4 (ulcer): 1 of 10; recurrencies: 2 of 10. For newly irradiated fields (n = 7) results were: follow-up: 2-20 months (median 5); LC: 6 of 7; acute reactions: Grade 1:4 of 7, Grade 2:3 of 7; intermediate/late skin reactions after minimum follow-up of 3 months (n = 5): Grade 2-3a: 2 of 5; recurrencies: 0 of 7. Local control could be achieved in 82% of the mold fields. Geometric

  13. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W. Sr.

    1992-01-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system use relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, Monte Carlo calculations were performed using the code Electron Gamma Shower (EGS4). Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessel sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was or cross fire between blood vessels was assumed. Results are useful in assessing the doses to blood and blood vessel walls for different nuclear medicine procedures

  14. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W.

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was assumed nor cross fire between vessel was assumed. Results are useful in assessing the dose in blood and blood vessel walls for different nuclear medicine procedures. 6 refs., 6 figs., 5 tabs

  15. Pathologic changes in the lung following single and multi-fraction irradiation

    International Nuclear Information System (INIS)

    Travis, E.L.; Harley, R.A.; Fenn, J.O.; Klobukowski, C.J.; Hargrove, H.B.

    1977-01-01

    The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of x-radiation, to 10 x 200 rad, or to 5 x 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the multi-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 x 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed

  16. Tirapazamine vs carbogen and nicotinamide with fractionated irradiation. What is the optimum time of giving tirapazamine during the course of irradiation?

    International Nuclear Information System (INIS)

    Elsaid, A.A.; Menke, D.; Dorie, M.J.; Brown, J.M.

    1996-01-01

    Purpose: 1) To compare in a fractionated regimen, with clinically relevant radiation doses, using human tumor xenografts, two radiation response modifiers that function by different mechanisms: A) Tirapazamine (TPZ), a bioreductive drug of the benzotriazine-di-N-oxide class which shows a highly selective cytotoxicity for hypoxic cells. B) Nicotinamide (NAM), an amide of vitamin B 3 , with Carbogen breathing (CBG), a combination that has been shown to reduce both acute (perfusion-limited) hypoxia and chronic (diffusion-limited) hypoxia. 2) To determine the optimum time of giving TPZ during the course of irradiation (XRT). Materials and Methods: Cell survival assays were used to examine the response of two different human tumor xenografts: FaDu, a carcinoma of the head and neck, and HT29, a colon carcinoma, in SCID mice. Growth delay studies were performed with the FaDu tumor to compare the following treatments: TPZ with XRT, NAM + CBG with XRT, and TPZ + NAM + CBG with XRT. Clinical phase I studies of TPZ have been completed and suggest that a fractionated course of 3 fractions/week of TPZ is tolerable at an effective cytotoxic dose. However, if hypoxic cells are present in the tumor on the days that TPZ is not given (i.e. rehypoxiation has occurred) then this will reduce the effectiveness of the drug-radiation combination. To investigate this we have given CBG and NAM on the days TPZ is not given with fractionated irradiation. The fractionated irradiation schedule consisted of 2.0 or 2.5 Gy once or twice daily for one or two weeks with and without drug pre treatment. TPZ was given i.p. at 0.08 mmol/kg 30 min before irradiation for the whole course, or for 3 fractions per week alone, or with 2 fractions per week of NAM and CBG. NAM was given i.p. at 1000 mg/kg, 1 hr prior to irradiation, with CBG exposure 5 min. prior to and during the irradiation. Another growth delay study is being performed to investigate which schedule produces the most enhancement: TPZ during

  17. Mathematical models in Slowpoke reactor internal irradiation site

    International Nuclear Information System (INIS)

    Raza, J.

    2007-01-01

    The main objective is to build representative mathematical models of neutron activation analysis in a Slowpoke internal irradiation site. Another significant objective is to correct various elements neutron activation analysis measured mass using these models. The neutron flux perturbation is responsible for the measured under-estimation of real masses. We supposed that neutron flux perturbation measurements taken during the Ecole Polytechnique de Montreal Slowpoke reactor first fuel loading were still valid after the second fuelling. .We also supposed that the thermal neutrons spatial and kinetic energies distributions as well as the absorption microscopic cross section dependence on the neutrons kinetic energies were important factors to satisfactorily represent neutron activation analysis results. In addition, we assumed that the neutron flux is isotropic in the laboratory system. We used experimental results from the Slowpoke reactor internal irradiation sites, in order to validate our mathematical models. Our models results are in close agreement with these experimental results..We established an accurate global mathematical correlation of the neutron flux perturbation in function of samples volumes and macroscopic neutron absorption cross sections. It is applicable to sample volumes ranging from 0,1 to 1,3 ml and macroscopic neutron absorption cross section up to 5 moles-b for seven (7) elements with atomic numbers (Z) ranging from 5 to 79. We first came up with a heuristic neutron transport mathematical semi-analytical model, in order to better understand neutrons behaviour in presence of one of several different nuclei samples volumes and mass. In order to well represent the neutron flux perturbation, we combined a neutron transport solution obtained from the spherical harmonics method of a finite cylinder and a mathematical expression combining two cylindrical harmonic functions..With the help of this model and the least squares method, we made extensive

  18. Study by internal friction of curing low temperature irradiation defects in graphite

    International Nuclear Information System (INIS)

    Rouby, Dominique.

    1974-01-01

    Micromechanical properties and anelastic effects of neutrons irradiated graphites at 300 and 77 0 K are investigated by internal friction analysis and elasticity modulus variations. Defects created by irradiation are studied and evolution versus dose and annealing is followed [fr

  19. Study about internal friction in deformed - and irradiated pure titanium

    International Nuclear Information System (INIS)

    Miyada, L.T.

    1979-01-01

    Internal friction and modulus are measured in pure Ti at low temperature using an inverted torsion-pendulum at about 1 Hz. The presence of four relaxation peaks P' sub(d)(-140 0 C), P sub(d)(-101 0 C), P' sub(α)(-75 0 C) and P sub(α)(-50 0 C) has been found, and effects of plastic deformation, heat treatment and neutron irradiation on these peaks are investigated in detail. Activation energies and frequency factors of P sub(d) and Pα peaks are consistent with the data in higher frequency range reproted by other workers. The P sub(d) and P' sub(d) peaks grow after deformation and tend to decay after annealing at high temperatures or after neutron irradiation. Both peaks are resonably interpreted in terms of dislocation relaxation mechanisms (Bordoni type) arising from thermally activated motion of dislocations in different slip planes of h.c.f. structure. Peierls stress of dislocations giving rise to each peak have calculated based on Seeger's theory, and found to be consistent with that of f.c.c. metals. On the other hand, P sub(α) and P' sub(α) peaks grow significantly at the expense of P sub(d) and P' sub(d) peaks after neutron irradiation in deformed samples. The behaviour of these peaks as a function of irradiation dose and annealing temperatures strongly indicated that they are due to relaxations resulting from dislocations-point defects interactions (Hasiguti type). It is tentatively suggested that P sub(α) and P' sub(α) peaks are related with interactions of dislocations with divacancies and single vacancies, respectively. Application of Schiller's model showed a consistent result with regard to the P' sub(α) peak experimentally observed. (Author) [pt

  20. Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Murai, Taro; Sato, Kengo; Iwabuchi, Michio; Manabe, Yoshihiko; Ogino, Hiroyuki; Iwata, Hiromitsu; Tatewaki, Koshi; Yokota, Naoki; Ohta, Seiji; Shibamoto, Yuta

    2016-03-01

    Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed. Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion. FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose-response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed. Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.

  1. Benefits of online in vivo dosimetry for single-fraction total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, David J., E-mail: davideaton@nhs.net [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Warry, Alison J. [Department of Radiotherapy Physics, University College London Hospital, London (United Kingdom); Trimble, Rachel E.; Vilarino-Varela, Maria J.; Collis, Christopher H. [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

    2014-01-01

    Use of a patient test dose before single-fraction total body irradiation (TBI) allows review of in vivo dosimetry and modification of the main treatment setup. However, use of computed tomography (CT) planning and online in vivo dosimetry may reduce the need for this additional step. Patients were treated using a supine CT-planned extended source-to-surface distance (SSD) technique with lead compensators and bolus. In vivo dosimetry was performed using thermoluminescent dosimeters (TLDs) and diodes at 10 representative anatomical locations, for both a 0.1-Gy test dose and the treatment dose. In total, 28 patients were treated between April 2007 and July 2013, with changes made in 10 cases (36%) following test dose results. Overall, 98.1% of measured in vivo treatment doses were within 10% of the prescribed dose, compared with 97.0% of test dose readings. Changes made following the test dose could have been applied during the single-fraction treatment itself, assuming that the dose was delivered in subportions and online in vivo dosimetry was available for all clinically important anatomical sites. This alleviates the need for a test dose, saving considerable time and resources.

  2. Benefits of online in vivo dosimetry for single-fraction total body irradiation

    International Nuclear Information System (INIS)

    Eaton, David J.; Warry, Alison J.; Trimble, Rachel E.; Vilarino-Varela, Maria J.; Collis, Christopher H.

    2014-01-01

    Use of a patient test dose before single-fraction total body irradiation (TBI) allows review of in vivo dosimetry and modification of the main treatment setup. However, use of computed tomography (CT) planning and online in vivo dosimetry may reduce the need for this additional step. Patients were treated using a supine CT-planned extended source-to-surface distance (SSD) technique with lead compensators and bolus. In vivo dosimetry was performed using thermoluminescent dosimeters (TLDs) and diodes at 10 representative anatomical locations, for both a 0.1-Gy test dose and the treatment dose. In total, 28 patients were treated between April 2007 and July 2013, with changes made in 10 cases (36%) following test dose results. Overall, 98.1% of measured in vivo treatment doses were within 10% of the prescribed dose, compared with 97.0% of test dose readings. Changes made following the test dose could have been applied during the single-fraction treatment itself, assuming that the dose was delivered in subportions and online in vivo dosimetry was available for all clinically important anatomical sites. This alleviates the need for a test dose, saving considerable time and resources

  3. Lipid peroxide levels of serum lipoprotein fractions of diabetic patients with angiopathy and 60Co-irradiated rabbit

    International Nuclear Information System (INIS)

    Tsunekawa, Hiroshi

    1982-01-01

    For a better understanding of the relationship between lipid peroxide (LPO) and vascular diseases, the author determined LPO levels and lipid contents of serum lipoprotein fractions of diabetics with angiopathy. The LPO level in high density lipoprotein (HDL) fraction of diabetic serum was significantly higher than that of normal serum whereas no significant increase was observed in the levels of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions of diabetic serum. As to the ratios of LPO to total lipids in these lipoprotein fractions, it was found that the ratio in HDL fraction of the diabetics was markedly higher than that of the normals. These results suggest that the increase in LPO levels in the sera of diabetic patiens is due to that in HDL fraction. To study further this problem, the author employed 60 Co-irradiated rabbit as a model, since it was already reported that radiation affects lipid metabolism and LPO formation, and that it induces the development of atherosclerosis. Upon irradiation with 60 Co ranging from 100R to 700R, serum LPO level of rabbit was significantly increased. Although elevation of LPO level was found in each serum lipoprotein fraction of VLDL, LDL and HDL, LPO level per lipid content was significantly increased only in HDL fraction. In the irradiated rabbit, significant elevation of the level of LPO was also observed in the liver, while no significant increase was found in the kidney and spleen. These results indicate that high level of LPO observed in the serum of irradiated rabbit would be the reflection of the increased LPO in the liver. (J.P.N.)

  4. Lipid peroxide levels of serum lipoprotein fractions of diabetic patients with angiopathy and /sup 60/Co-irradiated rabbit

    Energy Technology Data Exchange (ETDEWEB)

    Tsunekawa, Hiroshi [Nagoya Univ. (Japan). Faculty of Medicine

    1982-09-01

    For a better understanding of the relationship between lipid peroxide (LPO) and vascular diseases, the author determined LPO levels and lipid contents of serum lipoprotein fractions of diabetics with angiopathy. The LPO level in high density lipoprotein (HDL) fraction of diabetic serum was significantly higher than that of normal serum whereas no significant increase was observed in the levels of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions of diabetic serum. As to the ratios of LPO to total lipids in these lipoprotein fractions, it was found that the ratio in HDL fraction of the diabetics was markedly higher than that of the normals. These results suggest that the increase in LPO levels in the sera of diabetic patients is due to that in HDL fraction. To study further this problem, the author employed /sup 60/Co-irradiated rabbit as a model, since it was already reported that radiation affects lipid metabolism and LPO formation, and that it induces the development of atherosclerosis. Upon irradiation with /sup 60/Co ranging from 100R to 700R, serum LPO level of rabbit was significantly increased. Although elevation of LPO level was found in each serum lipoprotein fraction of VLDL, LDL and HDL, LPO level per lipid content was significantly increased only in HDL fraction. In the irradiated rabbit, significant elevation of the level of LPO was also observed in the liver, while no significant increase was found in the kidney and spleen. These results indicate that high level of LPO observed in the serum of irradiated rabbit would be the reflection of the increased LPO in the liver.

  5. Facts about food irradiation. A series of fact sheets from the International Consultative Group on Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-01

    The safety and benefits of foods processed by ionizing radiation are well documented. In an effort to provide governments, especially those of developing countries, with scientifically accurate information on issues of general interest to the public, the International Consultative Group on Food Irradiation (ICGFI), which was established under the aegis of the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the IAEA, decided at its 7th Annual Meeting in Rome, Italy, on October 1990, to issue a series of ''Fact Sheets'' on the subject. ICGFI, an inter-governmental body with a membership of 37 governments, has as one of its mandates the function to provide information to Member States of the FAO, WHO, and IAEA and to the three organizations themselves on the safe and proper use of food irradiation technology. The Fact Sheets included here cover issues relating to: status and trends; scientific and technical terms; food irradiation and radioactivity; chemical changes in irradiated food; nutritional quality of irradiated foods; genetic studies; microbiological safety of irradiated food; irradiation and food safety; irradiation and food additives and residues; packaging of irradiated foods; safety of irradiation facilities; controlling the process; food irradiation costs; and irradiated foods and the consumer. The Fact Sheets have been separately indexed and included in the INIS Database under Reference Numbers 23011206-23011217, 23011319 and 23012743. The Fact Sheets were first issued by the ICGFI Secretariat (Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria) in May 1991.

  6. Facts about food irradiation. A series of fact sheets from the International Consultative Group on Food Irradiation

    International Nuclear Information System (INIS)

    1991-12-01

    The safety and benefits of foods processed by ionizing radiation are well documented. In an effort to provide governments, especially those of developing countries, with scientifically accurate information on issues of general interest to the public, the International Consultative Group on Food Irradiation (ICGFI), which was established under the aegis of the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the IAEA, decided at its 7th Annual Meeting in Rome, Italy, on October 1990, to issue a series of ''Fact Sheets'' on the subject. ICGFI, an inter-governmental body with a membership of 37 governments, has as one of its mandates the function to provide information to Member States of the FAO, WHO, and IAEA and to the three organizations themselves on the safe and proper use of food irradiation technology. The Fact Sheets included here cover issues relating to: status and trends; scientific and technical terms; food irradiation and radioactivity; chemical changes in irradiated food; nutritional quality of irradiated foods; genetic studies; microbiological safety of irradiated food; irradiation and food safety; irradiation and food additives and residues; packaging of irradiated foods; safety of irradiation facilities; controlling the process; food irradiation costs; and irradiated foods and the consumer. The Fact Sheets have been separately indexed and included in the INIS Database under Reference Numbers 23011206-23011217, 23011319 and 23012743. The Fact Sheets were first issued by the ICGFI Secretariat (Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria) in May 1991

  7. In vivo dosimetry of high-dose fractionated irradiation in an experimental set-up with rats

    Energy Technology Data Exchange (ETDEWEB)

    Fortan, L; Van Hecke, H; Van Duyse, B; De Neve, W; De Meerleer, B [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Pattyn, P; Van Renthergem, K [Ghent University (Belgium). Dept. of Surgery

    1995-12-01

    The feasibility to irradiate a limited section of a rat abdomen with well-defined edges was assessed. Because of the relative small volume involved, in vivo dosimetry with TLDs was necessary in providing us information about the accuracy of the irradiation method. Three to five days prior to the start of the radiotherapy treatment, two plastic strips - each containing a TLD-dosimeter (Harshaw TLD10 LiF rods, 1 mm dia x 6 mm) sealed in polyethylene tubing, and a lead bean - were implanted in the rat abdomen. The plastic strips made a closed loop around the bowel, through the mesenterium, and were fixed with a single stitch on the inner abdominal wall. One loop was made in the hepatic area; another was made in the lower abdomen, around the rectosigmoid. Conscious animals were irradiated using a purpose-build plexi-holder, with rear legs immobilised to avoid longitudinal movements. The implanted lead beans enabled us to simulate the rat prior to each radiation session. This way, the radiation field could be set up individually for each rat, in such way that the rectosigmoid area received full dose and the hepatic area received no irradiation dose at all. Irradiation was carried out, using 5 MV photons of a linear accelerator. Fifteen animals per group were irradiated according a conventional (2.0 Gy / fraction; 5 fractions / week) or a hyperfractionated (1.6 Gy / fraction; 2 daily fractions; 5 days / week) schedule, with different total doses. Prior to implantation, TLDs were individually calibrated and checked for stability. After removal from the abdomen . TLDs were tested again for accuracy. TLDs with an unacceptable read-out curve were rejected (about 2 to 4 TLDs per group of 15). The obtained accumulated doses - as determined by TLD read-outs-were comparable to the theoretical doses, indicating that fractionated radiation of small fields, with well defined mark off, in rats is feasible.

  8. In vivo dosimetry of high-dose fractionated irradiation in an experimental set-up with rats

    International Nuclear Information System (INIS)

    Fortan, L.; Van Hecke, H.; Van Duyse, B.; De Neve, W.; De Meerleer, B.; Pattyn, P.; Van Renthergem, K.

    1995-01-01

    The feasibility to irradiate a limited section of a rat abdomen with well-defined edges was assessed. Because of the relative small volume involved, in vivo dosimetry with TLDs was necessary in providing us information about the accuracy of the irradiation method. Three to five days prior to the start of the radiotherapy treatment, two plastic strips - each containing a TLD-dosimeter (Harshaw TLD10 LiF rods, 1 mm dia x 6 mm) sealed in polyethylene tubing, and a lead bean - were implanted in the rat abdomen. The plastic strips made a closed loop around the bowel, through the mesenterium, and were fixed with a single stitch on the inner abdominal wall. One loop was made in the hepatic area; another was made in the lower abdomen, around the rectosigmoid. Conscious animals were irradiated using a purpose-build plexi-holder, with rear legs immobilised to avoid longitudinal movements. The implanted lead beans enabled us to simulate the rat prior to each radiation session. This way, the radiation field could be set up individually for each rat, in such way that the rectosigmoid area received full dose and the hepatic area received no irradiation dose at all. Irradiation was carried out, using 5 MV photons of a linear accelerator. Fifteen animals per group were irradiated according a conventional (2.0 Gy / fraction; 5 fractions / week) or a hyperfractionated (1.6 Gy / fraction; 2 daily fractions; 5 days / week) schedule, with different total doses. Prior to implantation, TLDs were individually calibrated and checked for stability. After removal from the abdomen . TLDs were tested again for accuracy. TLDs with an unacceptable read-out curve were rejected (about 2 to 4 TLDs per group of 15). The obtained accumulated doses - as determined by TLD read-outs-were comparable to the theoretical doses, indicating that fractionated radiation of small fields, with well defined mark off, in rats is feasible

  9. Combination Processes in Food Irradiation. Proceedings of an International Symposium on Combination Processes in Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1981-09-15

    Processes in Food Irradiation was held by the IAEA and FAO at the Bandaranaike Memorial International Conference Hall in Colombo on 24-28 November 1980, and the present volume contains the proceedings. One of the most effective means demonstrated of increasing the efficacy of irradiation in the control of food spoilage is the combination of a low irradiation dose with a mild heat treatment. Promising results were reported for the shelf-life extension of mangoes and papayas, and the disinfestation of dried dates. Commercial application of the heat-irradiation treatment for some fruits is expected to follow soon. The Symposium covered other topics, such as the mechanisms of sensitization of microorganisms by physical and chemical agents, improvement of the microbiological quality of foods by combination processes, and the aspects of the wholesomeness and legislation of the food irradiation process. A key issue in the general discussion was the recommendation on the acceptability of food irradiated up to an overall average dose of 10 kGy. This important recommendation had been achieved at a recently convened Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Foods (27 October - 3 November 1980, Geneva). The breakthrough on the toxicological acceptability constitutes a firm basis for going ahead speedily with the development of practical applications of food irradiation, which should take its rightful place among other food preservation methods in helping to provide more and better food to a world in need. The sponsoring organizations hope that the publication of these proceedings will encourage further research and development of food irradiation to the benefit of mankind.

  10. Combination Processes in Food Irradiation. Proceedings of an International Symposium on Combination Processes in Food Irradiation

    International Nuclear Information System (INIS)

    1981-01-01

    Processes in Food Irradiation was held by the IAEA and FAO at the Bandaranaike Memorial International Conference Hall in Colombo on 24-28 November 1980, and the present volume contains the proceedings. One of the most effective means demonstrated of increasing the efficacy of irradiation in the control of food spoilage is the combination of a low irradiation dose with a mild heat treatment. Promising results were reported for the shelf-life extension of mangoes and papayas, and the disinfestation of dried dates. Commercial application of the heat-irradiation treatment for some fruits is expected to follow soon. The Symposium covered other topics, such as the mechanisms of sensitization of microorganisms by physical and chemical agents, improvement of the microbiological quality of foods by combination processes, and the aspects of the wholesomeness and legislation of the food irradiation process. A key issue in the general discussion was the recommendation on the acceptability of food irradiated up to an overall average dose of 10 kGy. This important recommendation had been achieved at a recently convened Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Foods (27 October — 3 November 1980, Geneva). The breakthrough on the toxicological acceptability constitutes a firm basis for going ahead speedily with the development of practical applications of food irradiation, which should take its rightful place among other food preservation methods in helping to provide more and better food to a world in need. The sponsoring organizations hope that the publication of these proceedings will encourage further research and development of food irradiation to the benefit of mankind

  11. Enhanced sensitivity to dielectric function and thickness of absorbing thin films by combining total internal reflection ellipsometry with standard ellipsometry and reflectometry

    International Nuclear Information System (INIS)

    Lizana, A; Foldyna, M; Garcia-Caurel, E; Stchakovsky, M; Georges, B; Nicolas, D

    2013-01-01

    High sensitivity of spectroscopic ellipsometry and reflectometry for the characterization of thin films can strongly decrease when layers, typically metals, absorb a significant fraction of the light. In this paper, we propose a solution to overcome this drawback using total internal reflection ellipsometry (TIRE) and exciting a surface longitudinal wave: a plasmon-polariton. As in the attenuated total reflectance technique, TIRE exploits a minimum in the intensity of reflected transversal magnetic (TM) polarized light and enhances the sensitivity of standard methods to thicknesses of absorbing films. Samples under study were stacks of three films, ZnO : Al/Ag/ZnO : Al, deposited on glass substrates. The thickness of the silver layer varied from sample to sample. We performed measurements with a UV–visible phase-modulated ellipsometer, an IR Mueller ellipsometer and a UV–NIR reflectometer. We used the variance–covariance formalism to evaluate the sensitivity of the ellipsometric data to different parameters of the optical model. Results have shown that using TIRE doubled the sensitivity to the silver layer thickness when compared with the standard ellipsometry. Moreover, the thickness of the ZnO : Al layer below the silver layer can be reliably quantified, unlike for the fit of the standard ellipsometry data, which is limited by the absorption of the silver layer. (paper)

  12. Enhanced sensitivity to dielectric function and thickness of absorbing thin films by combining total internal reflection ellipsometry with standard ellipsometry and reflectometry

    Science.gov (United States)

    Lizana, A.; Foldyna, M.; Stchakovsky, M.; Georges, B.; Nicolas, D.; Garcia-Caurel, E.

    2013-03-01

    High sensitivity of spectroscopic ellipsometry and reflectometry for the characterization of thin films can strongly decrease when layers, typically metals, absorb a significant fraction of the light. In this paper, we propose a solution to overcome this drawback using total internal reflection ellipsometry (TIRE) and exciting a surface longitudinal wave: a plasmon-polariton. As in the attenuated total reflectance technique, TIRE exploits a minimum in the intensity of reflected transversal magnetic (TM) polarized light and enhances the sensitivity of standard methods to thicknesses of absorbing films. Samples under study were stacks of three films, ZnO : Al/Ag/ZnO : Al, deposited on glass substrates. The thickness of the silver layer varied from sample to sample. We performed measurements with a UV-visible phase-modulated ellipsometer, an IR Mueller ellipsometer and a UV-NIR reflectometer. We used the variance-covariance formalism to evaluate the sensitivity of the ellipsometric data to different parameters of the optical model. Results have shown that using TIRE doubled the sensitivity to the silver layer thickness when compared with the standard ellipsometry. Moreover, the thickness of the ZnO : Al layer below the silver layer can be reliably quantified, unlike for the fit of the standard ellipsometry data, which is limited by the absorption of the silver layer.

  13. VARIATIONS IN RADIATION SENSITIVITY AND REPAIR AMONG DIFFERENT HEMATOPOIETIC STEM-CELL SUBSETS FOLLOWING FRACTIONATED-IRRADIATION

    NARCIS (Netherlands)

    DOWN, JD; BOUDEWIJN, A; VANOS, R; THAMES, HD; PLOEMACHER, RE

    1995-01-01

    The radiation dose-survival of various hematopoietic cell subsets in murine bone marrow (BM) was determined in the cobblestone area forming cell (CAFC) assay under conditions of single-, split-, and multiple-dose irradiation. A greater recovery in cell survival with decreasing dose per fraction, or

  14. Analyse of the international recommendations on the calculation of absorbed dose in the biota

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.; Py Junior, Delcy de A.; Universidade Federal Fluminense; Kelecom, Alphonse

    2011-01-01

    This paper evaluates the recommendations of ICRP which has as objective the environmental radioprotection. It was analysed the recommendations 26, 60, 91, 103 and 108 of the ICRP. The ICRP-103 defined the concept of animal and plant of reference (APR) to be used in the RAP based on the calculation of absorbed dose based on APR concept. This last view allows to build a legal framework of environmental protection with a etic, moral and scientific visualization, more defensible than the anthropomorphic concept

  15. The significance of neuroendocrine system state in estimation of nonstochastic effects of small doses of internal irradiation. (An experimental study)

    International Nuclear Information System (INIS)

    Dedov, V.I.; Norets, T.A.; Stepanenko, V.F.; Dedenkov, A.N.

    1987-01-01

    Data on long-term complex investigations of nonstochastic effects of low doses of internal irradiation on the level of a whole organism are presented. Experiments have been carried out with mongrel rats of both sexes and different ages up to the moment of introduction of radioactive compounds. Action of relatively and uniformly distributing in the organism radiactive compounds of selenium - 75 and sulfur - 35, which were introduced once intravenously in quantities forming absorbed doses in average on the whole body and ovaries (0.5 Gy), on endocrine glands and critical organs (up to 1.0 Gy) has been used as models of internal radiation. Data, testifying to the fact that the neuroendocrinal system, despite the existing opinion, is sensitive to action of low doses of internal irradiation compared with the recommended one as an ultimate permissible one for nonstochastic effects ( 0.5 Sv), that permits to suggest for using factors of the functional state of the neuroendocrine system as an informative and sensitive criterium of estimation of biological action of low doses of internal radiation, have been obtained. These factors along with doses on critical organs permit to estimate the degree of dangerous action of different radionuclides on the organism level. Dynamic studying of activity factors of the neuroendocrine system with simultaneous analysis of the state of harmonically dependent processes permits to estimate functional possibilities of irradiated organism, its viability, especially under conditions requiring increased stress, as well as to take into account such factors modifying a biological effect as age, animal sex, the character of absorbed dose distribution

  16. A framework for consistent estimation of leaf area index, fraction of absorbed photosynthetically active radiation, and surface albedo from MODIS time-series data

    DEFF Research Database (Denmark)

    Xiao, Zhiqiang; Liang, Shunlin; Wang, Jindi

    2015-01-01

    -series MODerate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data. If the reflectance data showed snow-free areas, an ensemble Kalman filter (EnKF) technique was used to estimate leaf area index (LAI) for a two-layer canopy reflectance model (ACRM) by combining predictions from a phenology...... model and the MODIS surface reflectance data. The estimated LAI values were then input into the ACRM to calculate the surface albedo and the fraction of absorbed photosynthetically active radiation (FAPAR). For snow-covered areas, the surface albedo was calculated as the underlying vegetation canopy...... albedo plus the weighted distance between the underlying vegetation canopy albedo and the albedo over deep snow. The LAI/FAPAR and surface albedo values estimated using this framework were compared with MODIS collection 5 eight-day 1-km LAI/FAPAR products (MOD15A2) and 500-m surface albedo product (MCD43...

  17. Cell kinetic changes in the follicular epithelium of pig skin after irradiation with single and fractionated doses of X rays

    International Nuclear Information System (INIS)

    Morris, G.M.; Hopewell, J.W.

    1989-01-01

    Changes in cell kinetics of the follicular epithelium of the pig were studied after x-irradiation with single and fractionated doses (30 fractions/39 days) and compared with previous epidermal data. In the follicular epithelium there was an initial degenerative phase, when the rate of cell depletion was independent of radiation dose and mode of administration. Repopulation was seen between the 14th and 18th days after single doses (15 or 20 Gy) and by the 28th day after the start of irradiation with fractionated doses (52.3-80.0 Gy). The degree of cell depletion and subsequent rate of repopulation were independent of dose. The regenerative phase was characterized by an increased cell proliferation. Islands of cells with appearance similar to cells in the normal follicular epithelium, were seen 18 days after a single dose of 20 Gy and 42 days after the start of fractionated irradiation. Compared with the epidermis, the follicular epithelium exhibited considerably less evidence of damage after both single and fractionated doses. There was a lower incidence of degenerate cells and reduced levels of cell depletion in the follicular epithelium. (author)

  18. Acute response of mouse kidney clonogens to fractionated irradiation in situ and then assayed in primary culture

    International Nuclear Information System (INIS)

    Yeemin Jen; Hendry, J.H.

    1991-01-01

    The radiosensitivity of mouse kidney cells after in situ single-dose, 2, 8, and 16 fraction X-irradiations was measured in primary culture using a clonogenic assay. The assay was made 12 h after single doses or 12 h after the last dose of the multifraction regimens. When analysed using the linear-quadratic model, as predicted the individual α components for all the different fractionation schedules were not significantly different, and the changes in the β values were consistent with those expected on the basis of the reciprocal fraction numbers. When all four data sets were integrated to derive a common α/β ratio, the result was 4.4±1.3 (1SE) Gy, or 2.8±0.9 Gy (a better fit) if the single-dose data set was excluded. These values fall into the range reported for kidney using assays of tissue function at long times after irradiation. (author)

  19. Staged deployment of the International Fusion Materials Irradiation Facility

    International Nuclear Information System (INIS)

    Takeuchi, H.; Sugimoto, M.; Nakamura, H.

    2001-01-01

    The International Fusion Materials Irradiation Facility (IFMIF) employs an accelerator based D-Li intense neutron source as defined in the 1995-96 Conceptual Design Activity (CDA) study. In 1999, IEA mandated a review of the CDA IFMIF design for cost reduction without change to its original mission. This objective was accomplished by eliminating the previously assumed possibility of potential upgrade of IFMIF beyond the user requirements. The total estimated cost was reduced from $797.2 M to $487.8 M. An option of deployment in 3 stages was also examined to reduce the initial investment and annual expenditures during construction. In this scenario, full performance is achieved gradually with each interim stage as follows. 1st Stage: 20% operation for material selection for ITER breeding blanket, 2nd Stage: 50% operation to demonstrate materials performance of a reference alloy for DEMO, 3rd Stage: full performance operation ( 2MW/m 2 at 500cm 3 ) to obtain engineering data for potential DEMO materials under irradiation up to 100-200 dpa. In summary, the new, reduced cost IFMIF design and staged deployment still satisfies the original mission. The estimated cost of the 1st Stage facility is only $303.6 M making it financially much more attractive. Currently, IFMIF Key Element Technology Phase (KEP) is underway to reduce the key technology risk factors. (author)

  20. Concentration of Proteins and Protein Fractions in Blood Plasma of Chickens Hatched from Eggs Irradiated with Low Level Gamma Rays

    International Nuclear Information System (INIS)

    Kraljevic, P.; Vilic, M.; Simpraga, M.; Matisic, D.; Miljanic, S.

    2011-01-01

    In literature there are many results which have shown that low dose radiation can stimulate many physiological processes of living organism. In our earlier paper it was shown that low dose of gamma radiation has a stimulative effect upon metabolic process in chickens hatched from eggs irradiated before incubation. This was proved by increase of body weight gain and body weight, as well as by increase of two enzymes activities in blood plasma (aspartate aminotransferase and alanine aminotransferase) which play an important role in protein metabolism. Therefore, an attempt was made to determine the effect of eggs irradiation by low dose gamma rays upon concentration of total proteins and protein fractions in the blood plasma of chickens hatched from irradiated eggs. The eggs of heavy breed chickens were irradiated with a dose of 0.15 Gy gamma radiation (60Co) before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups of chickens. Blood samples were taken from the right jugular vein on the 1 s t and 3 r d day, or from the wing vein on days 5 and 7 after hatching. The total proteins concentration in the blood plasma was determined by the biuret method using Boehringer Mannheim GmbH optimized kits. The protein fractions (albumin, α 1 -globulin, α 2 -globulin, β- and γ-globulins) were estimated electrophoretically on Cellogel strips. The total proteins concentration was significantly decreased in blood plasma of chickens hatched from irradiated eggs on days 3 (P t h day (P 2 -globulin was decreased on days 1 (P t h day of life. Obtained results indicate that low dose of gamma radiation has mostly inhibitory effect upon concentration of total proteins and protein fractions in the blood plasma of chickens hatched from irradiated eggs before incubation. (author)

  1. Fractionation for Whole Breast Irradiation: An American Society for Radiation Oncology (ASTRO) Evidence-Based Guideline

    International Nuclear Information System (INIS)

    Smith, Benjamin D.; Bentzen, Soren M.; Correa, Candace R.; Hahn, Carol A.; Hardenbergh, Patricia H.; Ibbott, Geoffrey S.; McCormick, Beryl; McQueen, Julie R.; Pierce, Lori J.; Powell, Simon N.; Recht, Abram; Taghian, Alphonse G.; Vicini, Frank A.; White, Julia R.; Haffty, Bruce G.

    2011-01-01

    Purpose: In patients with early-stage breast cancer treated with breast-conserving surgery, randomized trials have found little difference in local control and survival outcomes between patients treated with conventionally fractionated (CF-) whole breast irradiation (WBI) and those receiving hypofractionated (HF)-WBI. However, it remains controversial whether these results apply to all subgroups of patients. We therefore developed an evidence-based guideline to provide direction for clinical practice. Methods and Materials: A task force authorized by the American Society for Radiation Oncology weighed evidence from a systematic literature review and produced the recommendations contained herein. Results: The majority of patients in randomized trials were aged 50 years or older, had disease Stage pT1-2 pN0, did not receive chemotherapy, and were treated with a radiation dose homogeneity within ±7% in the central axis plane. Such patients experienced equivalent outcomes with either HF-WBI or CF-WBI. Patients not meeting these criteria were relatively underrepresented, and few of the trials reported subgroup analyses. For patients not receiving a radiation boost, the task force favored a dose schedule of 42.5 Gy in 16 fractions when HF-WBI is planned. The task force also recommended that the heart should be excluded from the primary treatment fields (when HF-WBI is used) due to lingering uncertainty regarding late effects of HF-WBI on cardiac function. The task force could not agree on the appropriateness of a tumor bed boost in patients treated with HF-WBI. Conclusion: Data were sufficient to support the use of HF-WBI for patients with early-stage breast cancer who met all the aforementioned criteria. For other patients, the task force could not reach agreement either for or against the use of HF-WBI, which nevertheless should not be interpreted as a contraindication to its use.

  2. The dynamics of immunologic reactions in rats affected by repeated external γ-irradiation and internal irradiation with radionuclides

    International Nuclear Information System (INIS)

    Shubik, V.M.; Livshits, R.E.

    1975-01-01

    Nonspecific factors of immunity and formation of autoantibodies in rats exposed to comparable doses of repeated external γ-irradiation and of internal irradiation with Cs 137 , Sr 90 and I 131 chronically administered to animals have been studied comparatively. No essential variations have been found in changes induced in the immunologic reactions by chronic external and even internal γ-irradiation. Certain peculiarities have been revealed in the character of changes in the immunologic reactions depending on biophysical properties of the radionuclides used in the experiments

  3. Accelerator conceptual design of the international fusion materials irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, M.; Kinsho, M. [Japan Atomic Energy Res. Inst., Tokai, Ibaraki (Japan). Intense Neutron Source Lab.; Jameson, R.A.; Blind, B. [Los Alamos National Lab., NM (United States); Teplyakov, V. [Institute for High Energy Physics, Moscow (Russian Federation); Berwald, D.; Bruhwiler, D.; Peakock, M.; Rathke, J. [Northrop Grumman Corp., Bethpage, NY (United States); Deitinghoff, H.; Klein, H.; Pozimski, Y.; Volk, K. [Johann Wolfgang Goethe Univ., Frankfurt (Germany). Inst. fur Angewandte Phys.; Ferdinand, R.; Lagniel, J.-M. [CEA Saclay LNS, Gif-sur-Yvette (France); Miyahara, A. [Teikyo Univ., Tokyo (Japan); Olivier, M. [CEA DSM, Saclay, Gif-sur-Yvette (France); Piechowiak, E. [Northrop Grumman Corp., Baltimore, MD (United States); Tanabe, Y. [Toshiba Corp., Tsurumi-ku, Yokohama (Japan)

    1998-10-01

    The accelerator system of the international fusion materials irradiation facility (IFMIF) provides the 250-mA, 40-MeV continuous-wave deuteron beam at one of the two lithium target stations. It consists of two identical linear accelerator modules, each of which independently delivers a 125-mA beam to the common footprint of 20 cm x 5 cm at the target surface. The accelerator module consists of an ion injector, a 175 MHz RFQ and eight DTL tanks, and rf power supply system. The requirements for the accelerator system and the design concept are described. The interface issues and operational considerations to attain the proposed availability are also discussed. (orig.) 8 refs.

  4. Accelerator conceptual design of the international fusion materials irradiation facility

    International Nuclear Information System (INIS)

    Sugimoto, M.; Kinsho, M.; Teplyakov, V.; Berwald, D.; Bruhwiler, D.; Peakock, M.; Rathke, J.; Deitinghoff, H.; Klein, H.; Pozimski, Y.; Volk, K.; Miyahara, A.; Olivier, M.; Piechowiak, E.; Tanabe, Y.

    1998-01-01

    The accelerator system of the international fusion materials irradiation facility (IFMIF) provides the 250-mA, 40-MeV continuous-wave deuteron beam at one of the two lithium target stations. It consists of two identical linear accelerator modules, each of which independently delivers a 125-mA beam to the common footprint of 20 cm x 5 cm at the target surface. The accelerator module consists of an ion injector, a 175 MHz RFQ and eight DTL tanks, and rf power supply system. The requirements for the accelerator system and the design concept are described. The interface issues and operational considerations to attain the proposed availability are also discussed. (orig.)

  5. Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

    International Nuclear Information System (INIS)

    Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

    1985-01-01

    Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

  6. Photosynthesis, growth, and ultraviolet irradiance absorbance of Cucurbita pepo L. leaves exposed to ultraviolet-B radiation (280 to 315 nm)

    International Nuclear Information System (INIS)

    Sisson, W.B.

    1981-01-01

    Net photosynthesis, growth, and ultraviolet (uv) radiation absorbance were determined for the first leaf of Cucurbita pepo L. exposed to two levels of uv-B irradiation and a uv-B radiation-free control treatment. Absorbance by extracted flavonoid pigments and other uv-B radiation-absorbing compounds from the first leaves increased with time and level of uv-B radiation impinging on leaf surfaces. Although absorbance of uv-B radiation by extracted pigments increased substantially, uv-B radiation attenuation apparently was insufficient to protect completely the photosynthetic apparatus or leaf growth processes. Leaf expansion was repressed by daily exposure to 1365 Joules per meter per day of biologically effective uv-B radiation by not by exposure to 660 Joules per meter per day. Photosynthesis measured through ontogenesis of the first leaf was depressed by both uv-B radiation treatments. Repression of photosynthesis by uv-B radiation was especially evident during the ontogenetic period of maximum photosynthetic activity

  7. Factors associated with pulmonary toxicity after myeloablative conditioning using fractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Hwa Kyung; Yoon, Hong In; Cho, Jae Ho [Yonsei Cancer Center, Yonsei University College of Medicine, Seoul (Korea, Republic of); and others

    2017-09-15

    Pulmonary toxicities, including infectious pneumonia (IP) and idiopathic pneumonia syndrome (IPS), are serious side effects of total body irradiation (TBI) used for myeloablative conditioning. This study aimed to evaluate clinical factors associated with IP and IPS following TBI. Fifty-eight patients with hematologic malignancies who underwent TBI before allogeneic hematopoietic stem cell transplantation between 2005 and 2014 were reviewed. Most patients (91%) received 12 Gy in 1.5 Gy fractions twice a day. Pulmonary toxicities were diagnosed based on either radiographic evidence or reduced pulmonary function, and were subdivided into IP and IPS based on the presence or absence of concurrent infection. Pulmonary toxicities developed in 36 patients (62%); 16 (28%) had IP and 20 (34%) had IPS. IP was significantly associated with increased treatment-related mortality (p = 0.028) and decreased survival (p = 0.039). Multivariate analysis revealed that the risk of developing IPS was significantly higher in patients who received stem cells from a matched unrelated donor than from a matched sibling donor (p = 0.021; hazard ratio [HR] = 12.67; 95% confidence interval [CI], 1.46–110.30). Combining other conditioning agents with cyclophosphamide produced a higher tendency to develop IP (p = 0.064; HR = 6.19; 95% CI, 0.90–42.56). IP and IPS involve different risk factors and distinct pathogeneses that should be considered when planning treatments before and after TBI.

  8. Fractionated irradiation-induced EMT-like phenotype conferred radioresistance in esophageal squamous cell carcinoma

    Science.gov (United States)

    Zhang, Hongfang; Luo, Honglei; Jiang, Zhenzhen; Yue, Jing; Hou, Qiang; Xie, Ruifei; Wu, Shixiu

    2016-01-01

    The efficacy of radiotherapy, one major treatment modality for esophageal squamous cell carcinoma (ESCC) is severely attenuated by radioresistance. Epithelial-to-mesenchymal transition (EMT) is a cellular process that determines therapy response and tumor progression. However, whether EMT is induced by ionizing radiation and involved in tumor radioresistance has been less studied in ESCC. Using multiple fractionated irradiation, the radioresistant esophageal squamous cancer cell line KYSE-150R had been established from its parental cell line KYSE-150. We found KYSE-150R displayed a significant EMT phenotype with an elongated spindle shape and down-regulated epithelial marker E-cadherin and up-regulated mesenchymal marker N-cadherin in comparison with KYSE-150. Furthermore, KYSE-150R also possessed some stemness-like properties characterized by density-dependent growth promotion and strong capability for sphere formation and tumorigenesis in NOD-SCID mice. Mechanical studies have revealed that WISP1, a secreted matricellular protein, is highly expressed in KYSE-150R and mediates EMT-associated radioresistance both in ESCC cells and in xenograft tumor models. Moreover, WISP1 has been demonstrated to be closely associated with the EMT phenotype observed in ESCC patients and to be an independent prognosis factor of ESCC patients treated with radiotherapy. Our study highlighted WISP1 as an attractive target to reverse EMT-associated radioresistance in ESCC and can be used as an independent prognostic factor of patients treated with radiotherapy. PMID:27125498

  9. Marrow transplantation for leukemia following fractionated total body irradiation. A comparative trial of methotrexate and cyclosporine

    International Nuclear Information System (INIS)

    Irle, C.; Deeg, H.J.; Buckner, C.D.; Swedish Hospital Medical Center, Seattle, WA; Veterans Administration Hospital, Seattle, WA; Washington Univ., Seattle

    1985-01-01

    Fifty-six patients, 30-47 yr of age, with leukemia in relapse received allogeneic marrow transplants from HLA-identical siblings. All patients were treated with cyclophosphamide (120 mg/kg) and 7 daily fractions of 2.25 Gy of total body irradiation (TBI) for seven consecutive days. Nine patients (16%) are currently alive, free of disease, 324-845 days from transplantation. Actuarial relapse and survival rates at 2 yr were 56% and 9.5% respectively. These data were not remarkably different from those in previous studies using 10 Gy of TBI administered as a single dose. Thirty patients were randomized to receive methotrexate (MTX) and 26 to receive cyclosporine (CSP) as postgrafting prophylaxis for acute graft-versus-host disease (GVHD). Probability of developing significant acute GVHD by day 100 post-transplant was 71% for patients in the MTX group and 45% for patients in the CSP group (p<0.05). Probability of relapse was 37% for patients in the MTX group and 70% for patients in the CSP group (p<0.05). Transplant-related deaths were more frequent in the MTX group and leukemic deaths more frequent in the CSP group although this may have been related to an uneven distribution of high-risk patients. Long term disease-free survival was comparable. (author)

  10. Enzyme-activity mutations detected in mice after paternal fractionated irradiation

    International Nuclear Information System (INIS)

    Charles, D.J.; Pretsch, W.

    1986-01-01

    (101/E1 X C3H/E1)F 1 -hybrid male mice were exposed in a 24-h fractionation interval to either 3.0 + 3.0-Gy or 5.1 + 5.1-Gy X-irradiation, and mated to untreated Test-stock females. The offspring were examined for mutations at 7 recessive specific loci and for activity alterations of erythrocyte enzymes controlled presumably by 12 loci. No enzyme-activity mutant was found in 3610 F 1 -offspring of the control group. In the experimental groups, no mutant was detected in 533 (3.0 + 3.0 Gy) and 173 (5.1 + 5.1 Gy) offspring from postspermatogonial germ cells treated. After treatment of spermatogonia, 1 mutant in 3388 F 1 -offspring of the 3.0 + 3.0-Gy group, and 5 mutants in 3187 F 1 offspring of the 5.1 + 5.1-Gy group were found. The mutants were all genetically confirmed. The frequency (expressed as mutants/locus/gamete) of enzyme-activity mutations is 2 (5.1 + 5.1-Gy group) to 10 (3.0 + 3.0-Gy group) times lower than the frequency of recessive specific-locus mutations. (Auth.)

  11. Fractionated irradiation-induced EMT-like phenotype conferred radioresistance in esophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhang, Hongfang; Luo, Honglei; Jiang, Zhenzhen; Yue, Jing; Hou, Qiang; Xie, Ruifei; Wu, Shixiu

    2016-01-01

    The efficacy of radiotherapy, one major treatment modality for esophageal squamous cell carcinoma (ESCC) is severely attenuated by radioresistance. Epithelial-to-mesenchymal transition (EMT) is a cellular process that determines therapy response and tumor progression. However, whether EMT is induced by ionizing radiation and involved in tumor radioresistance has been less studied in ESCC. Using multiple fractionated irradiation, the radioresistant esophageal squamous cancer cell line KYSE-150R had been established from its parental cell line KYSE-150. We found KYSE-150R displayed a significant EMT phenotype with an elongated spindle shape and down-regulated epithelial marker E-cadherin and up-regulated mesenchymal marker N-cadherin in comparison with KYSE-150. Furthermore, KYSE-150R also possessed some stemness-like properties characterized by density-dependent growth promotion and strong capability for sphere formation and tumorigenesis in NOD-SCID mice. Mechanical studies have revealed that WISP1, a secreted matricellular protein, is highly expressed in KYSE-150R and mediates EMT-associated radioresistance both in ESCC cells and in xenograft tumor models. Moreover, WISP1 has been demonstrated to be closely associated with the EMT phenotype observed in ESCC patients and to be an independent prognosis factor of ESCC patients treated with radiotherapy. Our study highlighted WISP1 as an attractive target to reverse EMT-associated radioresistance in ESCC and can be used as an independent prognostic factor of patients treated with radiotherapy

  12. Factors associated with pulmonary toxicity after myeloablative conditioning using fractionated total body irradiation

    International Nuclear Information System (INIS)

    Byun, Hwa Kyung; Yoon, Hong In; Cho, Jae Ho

    2017-01-01

    Pulmonary toxicities, including infectious pneumonia (IP) and idiopathic pneumonia syndrome (IPS), are serious side effects of total body irradiation (TBI) used for myeloablative conditioning. This study aimed to evaluate clinical factors associated with IP and IPS following TBI. Fifty-eight patients with hematologic malignancies who underwent TBI before allogeneic hematopoietic stem cell transplantation between 2005 and 2014 were reviewed. Most patients (91%) received 12 Gy in 1.5 Gy fractions twice a day. Pulmonary toxicities were diagnosed based on either radiographic evidence or reduced pulmonary function, and were subdivided into IP and IPS based on the presence or absence of concurrent infection. Pulmonary toxicities developed in 36 patients (62%); 16 (28%) had IP and 20 (34%) had IPS. IP was significantly associated with increased treatment-related mortality (p = 0.028) and decreased survival (p = 0.039). Multivariate analysis revealed that the risk of developing IPS was significantly higher in patients who received stem cells from a matched unrelated donor than from a matched sibling donor (p = 0.021; hazard ratio [HR] = 12.67; 95% confidence interval [CI], 1.46–110.30). Combining other conditioning agents with cyclophosphamide produced a higher tendency to develop IP (p = 0.064; HR = 6.19; 95% CI, 0.90–42.56). IP and IPS involve different risk factors and distinct pathogeneses that should be considered when planning treatments before and after TBI

  13. International training workshop on quality control and management of food irradiation

    International Nuclear Information System (INIS)

    2004-01-01

    The International Training Workshop on Quality Control and Management of Food Indantrione was hold from 28-30, August, 2004 in Beijing, China and organized by Chinese Society of Nuclear Agriculture and China Isotope and Radiation Association. 10 Articles were collected in this symposium including training lectures. The contents included: international developments in food irradiation, Quality control and magement of food irradiation, industrializing development of irradiated food in China, Food irradiator and its quality management, research in setting standard for enterprise about irradiated products and etc.

  14. Glycolysis-related gene induction and ATP reduction during fractionated irradiation. Markers for radiation responsiveness of human tumor xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Goetze, K.; Meyer, S.S.; Mueller-Klieser, W. [University Medical Center Mainz Univ. (Germany). Inst. of Physiology and Pathophysiology; Yaromina, A. [Technical Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Zips, D. [University Hospital Tuebingen (Germany). Dept. of Radiation Oncology; Baumann, M. [Technical Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; University Hospital Dresden Technical Univ. Dresden (Germany). Dept. of Radiation Oncology

    2013-09-15

    Background and purpose: Lactate was previously shown to be a prognostic but not a predictive pre-therapeutic marker for radiation response of tumor xenografts. We hypothesize that metabolic changes during fractionated irradiation may restrict the predictiveness of lactate regarding tumor radiosensitivity. Materials and methods: Tumor xenografts were generated in nude mice by implanting 4 head and neck squamous cell carcinoma lines with different sensitivities to fractionated irradiation. Tumors were irradiated with up to 15 fractions of 2 Gy over a period of 3 weeks, and ATP and lactate levels were measured in vital tumor areas with induced metabolic bioluminescence imaging. Corresponding changes in mRNA expression of glycolysis-related genes were determined by quantitative RT-PCR. Results: Lactate content decreased significantly in 3 out of 4 cell lines in the course of irradiation showing no correlation with cell line-specific radiosensitivity. Radiation-induced changes in ATP levels and glycolysis-related mRNA expression, however, only occurred in radiosensitive or intermediately radioresistant xenografts, whereas these parameters remained unchanged in radioresistant tumors. Conclusion: Sensitivity-related differences in the transcriptional response of tumors to radiotherapy may be exploited in the clinic for better individualization of tumor treatment. (orig.)

  15. Allograft tolerance in pigs after fractionated lymphoid irradiation. II. Kidney graft after conventional total lymphoid irradiation and bone marrow cell grafting

    International Nuclear Information System (INIS)

    Fradelizi, D.; Mahouy, G.; de Riberolles, C.; Lecompte, Y.; Alhomme, P.; Douard, M.C.; Chotin, G.; Martelli, H.; Daburon, F.; Vaiman, M.

    1981-01-01

    Experiments with pigs have been performed in order to establish bone marrow chimerism and kidney graft tolerance between SLA genotyped semi-incompatible animals. Recipients were conditioned by means of conventional fractionated total lymphoid irradiation (TLI) delivered by a vertical cobalt source. The principal lymphoid regions of the pig, including thymus and spleen, were submitted to irradiation. Two protocols were tested: A = 250 cGy four times a week x 13 times (TLI) (two animals) and B = 350 cGy three times a week x 8 times (TLI) (four animals). Bone marrow cells were injected 24 h after the last irradiation. One day later, bilateral nephrectomy and the graft of one kidney from the bone marrow cell donor were performed simultaneously. Results convinced us that application of the TLI protocol to humans is not yet practicable and that further experimental work is needed

  16. Impact of anemia prevention by recombinant human erythropoietin on the sensitivity of xenografted glioblastomas to fractionated irradiation

    International Nuclear Information System (INIS)

    Stueben, G.; Poettgen, C.; Knuehmann, K.; Sack, H.; Stuschke, M.; Thews, O.; Vaupel, P.

    2003-01-01

    Background: Pronounced oxygen deficiency in tumors which might be caused by a diminished oxygen transport capacity of the blood (e.g., in anemia) reduces the efficacy of ionizing radiation. The aim of this study was to analyze whether anemia prevention by recombinant human erythropoietin (rHuEPO) affects the radiosensitivity of human glioblastoma xenografts during fractionated irradiation. Material and Methods: Anemia was induced by total body irradiation (TBI, 2 x 4 Gy) of mice prior to tumor implantation into the subcutis of the hind leg. In one experimental group, the development of anemia was prevented by rHuEPO (750 U/kg s.c.) given three times weekly starting 10 days prior to TBI. 13 days after tumor implantation (tumor volume approx. 40 mm 3 ), fractionated irradiation (4 x 7 Gy, one daily fraction) of the glioblastomas was performed resulting in a growth delay with subsequent regrowth of the tumors. Results: Compared to nonanemic control animals (hemoglobin concentration cHb = 14.7 g/dl), the growth delay in anemic mice (cHb = 9.9 g/dl) was significantly shorter (49 ± 5 days vs. 79 ± 4 days to reach four times the initial tumor volume) upon fractionated radiation. The prevention of anemia by rHuEPO treatment (cHb = 13.3 g/dl) resulted in a significantly prolonged growth delay (61 ± 5 days) compared to the anemia group, even though the growth inhibition found in control animals was not completely achieved. Conclusions: These data indicate that moderate anemia significantly reduces the efficacy of radiotherapy. Prevention of anemia with rHuEPO partially restores the radiosensitivity of xenografted glioblastomas to fractionated irradiation. (orig.)

  17. Effects of Si3+ and H+ Irradiation on Tungsten Evaluated by Internal Friction Method

    International Nuclear Information System (INIS)

    Hu Jing; Wang Xianping; Fang Qianfeng; Liu Changsong; Zhang Yanwen; Zhao Ziqiang

    2013-01-01

    Effects of Si 3+ and H + irradiation on tungsten were investigated by internal friction (IF) technique. Scanning electron microscope (SEM) analysis revealed that sequential dual Si+H irradiation resulted in more serious damage than single Si irradiation. After irradiation, the IF background was significantly enhanced. Besides, two obvious IF peaks were initially found in temperature range of 70∼330 K in the sequential Si+H irradiated tungsten sample. The mechanism of increased IF background for the irradiated samples was suggested to originate from the high density dislocations induced by ion irradiation. On the other hand, the relaxation peak P L and non-relaxation peak P H in the Si+H irradiated sample were ascribed to the interaction process of hydrogen atoms with mobile dislocations and transient processes of hydrogen redistribution, respectively. The obtained experimental results verified the high sensitivity of IF method on the irradiation damage behaviors in nuclear materials

  18. Hypo-fractionated whole breast irradiation: Pro and cons; Irradiation hypofractionnee dans le cancer du sein: pour ou contre?

    Energy Technology Data Exchange (ETDEWEB)

    Cutuli, B. [Institut du cancer Courlancy, 38, rue de Courlancy, 51100 Reims (France); Fourquet, A. [Institut Curie, 26, rue d' Ulm, 75005 Paris (France)

    2011-10-15

    The continuous increase of breast cancer (BC) incidence, the logistic constraints of the protracted standard 5-week radiations regimen have led to test short hypo-fractionated whole breast radiation therapy schemes. Three prospective randomized trials and a pilot trial have been published. Large numbers of patients were included, with follow-up duration ranging from 5 to 12 years. The conclusions of these trials were similar, showing local control and toxicity equivalent to those of the standard regimen, and supporting the use of three schemes: 42.5 Gy/16 fractions/3 weeks, 40 Gy/15 fractions/3 weeks or 41.6 Gy/13 fractions/5 weeks. However, the patients in these trials had favourable prognostic factors, were treated to the breast only and the boost dose, when indicated, was delivered with a standard fractionation. Hypo-fractionated treatment can only be recommended in patients treated to the breast only, without nodal involvement, with grade < 3 tumours and who are not candidate to chemotherapy. If a boost is to be given, a standard fractionation should be used. Particular care should be taken to avoid heterogeneities leading to high fractional doses to organs at risk (lung and heart). (authors)

  19. Electron absorbed fractions in skeletal soft tissues based on red bone marrow segmentation at runtime in muCT images of human trabecular bone;Fracoes absorvidas de eletrons em tecidos moles do esqueleto avaliadas com base na segmentacao em tempo de execucao da medula ossea vermelha contida em imagens muCT do osso trabecular humano

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, J.W. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, Recife, PE (Brazil); Kramer, R. [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Khoury, H.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Robson-Brown, K. [University of Bristol, Bristol (United Kingdom). Dept. of Archaeology and Anthropology

    2009-07-01

    Skeletal dosimetry determines equivalent dose or absorbed fractions in the red bone marrow (RBM) and the osteogenic cells on bone surfaces (BSC). Following a method used earlier for the BSC, RBM and yellow bone marrow (YBM) have been segmented in the marrow cavities of muCT images of human spongiosa at runtime, i.e. during the execution of the Monte Carlo calculation, which avoids the necessity to segment RBM and YBM externally in muCT images for many different cellularities and to store the data. Using this internal RBM/YBM segmentation, this study presents electron absorbed fractions for the RBM and the BSC as a function of the voxel resolution and also compares the results with data from other investigations. (author)

  20. Absorbed dose at subcellular level by Monte Carlo simulation for a {sup 99m}Tc-peptide with nuclear internalization

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L.; Ferro F, G. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Santos C, C. L., E-mail: leticia.rojas@inin.gob.m [Universidad Autonoma del Estado de Mexico, Paseo Tollocan esquina Paseo Colon s/n, Toluca 50120, Estado de Mexico (Mexico)

    2010-10-15

    The utility of radiolabeled peptides for the early and specific diagnosis of cancer is being investigated around the world. Recent investigations have demonstrated the specificity of {sup 99m}Tc-bombesin conjugates to target breast and prostate cancer cells. The novel idea of adding the Tat (49-57) peptide to the radiopharmaceutical in order to penetrate the cell nucleus is a new proposal for therapy at cellular level. {sup 99m}Tc radionuclide produces Auger energy of 0.9 keV/decay and internal conversion electron energy of 15.4 keV/decay, which represent 11.4% of the total {sup 99m}Tc energy released per decay. It is expected that the dose delivered at specific microscopic levels in cancer cells induce a therapeutic effect. The aim of this research was to assess in vitro internalization kinetics in breast and prostate cancer cells of {sup 99m}Tc-Tat(49-57)-bombesin and to evaluate the radiation absorbed dose at subcellular level simulating the electron transport. The pen main program from the 2006 version of the Penelope code was used to simulate and calculate the absorbed dose by Auger and internal conversion electron contribution in the membrane, cytoplasm and nucleus of Pc-3 prostate cancer and MCF7 and MDA human breast cancer cell lines. Nuclear data were obtained from the 2002 BNM-LNHB {sup 99m}Tc decay scheme. The spatial distribution of the absorbed doses to the membrane, cytoplasm and nucleus were calculated using a geometric model built from real images of cancer cells. The elemental cell composition was taken from the literature. The biokinetic data were obtained evaluating total disintegrations in each subcellular compartment by integration of the time-activity curves acquired from experimental data. Results showed that 61, 63 and 46% of total disintegrations per cell-bound {sup 99m}Tc-Tat-Bn activity unit occurred in the nucleus of Pc-3, MCF7 and MDA-MB231 respectively. {sup 99m}Tc--Tat-Bn absorbed doses were 1.78, 5.76 and 2.59 Gy/Bq in the nucleus of

  1. The international protocol for the dosimetry of external radiotherapy beams based on standards of absorbed dose to water

    International Nuclear Information System (INIS)

    Andreo, P.

    2001-01-01

    An International Code of Practice (CoP, or dosimetry protocol) for external beam radiotherapy dosimetry based on standards of absorbed dose to water has been published by the IAEA on behalf of IAEA, WHO, PAHO and ESTRO. The CoP provides a systematic and internationally unified approach for the determination of the absorbed dose to water in reference conditions with radiotherapy beams. The development of absorbed-dose-to-water standards for high-energy photons and electrons offers the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. Many laboratories already provide calibrations at the radiation quality of 60Co gamma-rays and some have extended calibrations to high-energy photon and electron beams. The dosimetry of kilovoltage x-rays, as well as that of proton and ion beams can also be based on these standards. Thus, a coherent dosimetry system based on the same formalism is achieved for practically all radiotherapy beams. The practical use of the CoP as simple. The document is formed by a set of different CoPs for each radiation type, which include detailed procedures and worksheets. All CoPs are based on ND,w chamber calibrations at a reference beam quality Qo, together with radiation beam quality correction factors kQ preferably measured directly for the user's chamber in a standards laboratory. Calculated values of kQ are provided together with their uncertainty estimates. Beam quality specifiers are 60Co, TPR20,10 (high-energy photons), R50 (electrons), HVL and kV (x-rays) and Rres (protons and ions) [es

  2. Absorbed Dose Distributions in Small Copper Wire Insulation due to Multiple-Sided Irradiations by 0.4 MeV Electrons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.; Pedersen, Walther Batsberg

    1979-01-01

    When scanned electron beams are used to crosslink polymeric insulation of wire and cable, an important goal is to achieve optimum uniformity of absorbed dose distributions. Accurate measurements of dose distributions in a plastic dosimeter simulating a typical insulating material (polyethylene......) surrounding a copper wire core show that equal irradiations from as few as four sides give approximately isotropy and satisfactorily uniform energy depositions around the wire circumference. Electron beams of 0.4 MeV maximum energy were used to irradiate wires having a copper core of 1.0 mm dia....... and insulation thicknesses between 0.4 and 0.8 mm. The plastic dosimeter simulating polyethylene insulations was a thin radiochromic polyvinyl butyral film wrapped several times around the copper wire, such that when unwrapped and analyzed optically on a scanning microspectrophotometer, high-resolution radial...

  3. International Cooperation to Establish Standard Operating Procedure (SOP) for Quarantine Management of Irradiated Foods in International Trade

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. W.; Byun, M. W.; Kim, J. H.; Choi, J. I.; Song, B. S.; Yoon, Y. H.; Kim, D. H.; Kim, W. G.; Kim, K. P.

    2010-02-15

    {center_dot} Development of SOPs through various research activities such as building international cooperation, and analysing current status of food irradiation in domestic and international markets, export and import, international market size, and of R and D - Analysis of examples for quarantine management in agricultural product exporting countries and use of irradiation technology for agricultural product quarantine, and changes in international quarantine management - Analysis of SOPs for food irradiation quarantine in international organization (CODEX, IPPC, WHO). U.S, EU, China, India, and Australia. - Collaborative researches of India/Korea and China/Korea entered into an agreement for market trials {center_dot} Publishment of irradiation quarantine management SOPs agreed to CODEX standards - Collaborative researches for quarantine management, avoiding Technical Barrier to Trade (TBT), and Sanitary Phytosanitary Measures were conducted, and advanced SOPs agreed with WTO/FTA system were published

  4. International Cooperation to Establish Standard Operating Procedure (SOP) for Quarantine Management of Irradiated Foods in International Trade

    International Nuclear Information System (INIS)

    Lee, J. W.; Byun, M. W.; Kim, J. H.; Choi, J. I.; Song, B. S.; Yoon, Y. H.; Kim, D. H.; Kim, W. G.; Kim, K. P.

    2010-02-01

    · Development of SOPs through various research activities such as building international cooperation, and analysing current status of food irradiation in domestic and international markets, export and import, international market size, and of R and D - Analysis of examples for quarantine management in agricultural product exporting countries and use of irradiation technology for agricultural product quarantine, and changes in international quarantine management - Analysis of SOPs for food irradiation quarantine in international organization (CODEX, IPPC, WHO). U.S, EU, China, India, and Australia. - Collaborative researches of India/Korea and China/Korea entered into an agreement for market trials · Publishment of irradiation quarantine management SOPs agreed to CODEX standards - Collaborative researches for quarantine management, avoiding Technical Barrier to Trade (TBT), and Sanitary Phytosanitary Measures were conducted, and advanced SOPs agreed with WTO/FTA system were published

  5. Radioactive caesium in a boreal forest ecosystem and internally absorbed dose to man

    International Nuclear Information System (INIS)

    Bergman, R.; Johansson, L.

    1989-01-01

    Different aspects dealing with water-soil, soil-plant and plant-herbivore interactions are studied. The study area is located to the Forest Research Station at Svartberget 50 km west of Umea in Vaesterbotten. An important topic in this study concerns the transport of caesium in food chains to man. Consumption of forest products by man i.e. game (primarily moose) and berries constitutes the major pathway of radioactive caesium to man. Moose meat contributes to about 30% of the total meat consumption in Vaesterbotten and the average over the Swedish population has remained at the level of 5-10% during the present decade. In order to assess the absorbed dose resulting from intake via these food products over a long period of time, knowledge about the long term behaviour of caesium in the biotic community is studied. (orig./HP)

  6. Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

    Science.gov (United States)

    Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

    2016-01-01

    The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

  7. Epinephrine ameliorating response of serum proteins and protein fractions to whole body gamma irradiation in albino rats

    International Nuclear Information System (INIS)

    Mohamed, M.A.; Saada, H.N.; Roushdy, H.M.; Awad, O.M.; El-Sayed, M.M.; Azab, Kh.Sh.

    1997-01-01

    The present study was carried out to investigate the role of epinephrine in modifying the radiation induced effects on serum protein as presented by total protein, protein fractions and albumin/globulin (A/G) ratio in adult albino rats. Epinephrine was intraperitoneally injected at a concentration of 200 M/g body weight, 15 min, pre-9 or just after 0 whole body gamma-irradiation of rats at a dose of 6 Gy (single dose). Studies have been undertaken at periods of 1 hr, 4 hrs, 1,3 and 7 days after irradiation. Data of the present study revealed that whole body gamma-irradiation induced significant decreased in the total content of serum protein and albumin at 1,3 and 7 days post radiation exposure alpha 1-globulin significantly increased only on the 1 st hr post-irradiation, however alpha 1-globulin significantly increased along all the experimental periods. B-globulin insignificantly changed after irradiation but gamma-globulin significantly decreased during the experimental periods. These changes were associated with significant decreases in A/G ratio at 3 and 7 days post-irradiation. Administration of epinephrine pre-or after radiation exposure produced some amelioration in the radiation induced changes in the studied parameters. So, it could be concluded that epinephrine plays a beneficial radioprotective role through its pharmacologic properties

  8. Absorbed Internal Dose Conversion Coefficients for Domestic Reference Animals and Plant

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Choi, Yong Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-02-15

    This paper describes the methodology of calculating the internal dose conversion coefficient in order to assess the radiological impact on non-human species. This paper also presents the internal dose conversion coefficients of 25 radionuclides ({sup 3}H, {sup 7}Be, {sup 14}C, {sup 40}K, {sup 51}Cr, {sup 54}Mn, {sup 59}Fe, {sup 58}Co, {sup 60}Co, {sup 65}Zn, {sup 90}Sr, '9{sup 5}Zr, {sup 95}Nb, {sup 99}Tc, {sup 106}Ru, {sup 129}I, {sup 131}I, {sup 136}Cs, {sup 137}Cs, {sup 140}Ba, {sup 140}La, {sup 144}Ce, {sup 238}U, {sup 239}Pu, {sup 240}Pu) for domestic seven reference animals (roe deer, rat, frog, snake, Chinese minnow, bee, and earthworm) and one reference plant (pine tree). The uniform isotropic model was applied in order to calculate the internal dose conversion coefficients. The calculated internal dose conversion coefficient (muGyd{sup -1} per Bqkg{sup -1}) ranged from 10{sup -6} to 10{sup -2} according to the type of radionuclides and organisms studied. It turns out that the internal does conversion coefficient was higher for alpha radionuclides, such as {sup 238}U, {sup 239}Pu, and {sup 240}Pu, and for large organisms, such as roe deer and pine tree. The internal dose conversion coefficients of {sup 239}Pu, {sup 240}Pu, {sup 238}U, {sup 14}C, {sup 3}H and {sup 99}Tc were independent of the organism

  9. Radiobiological basis of total body irradiation with different dose rate and fractionation: repair capacity of hemopoietic cells

    International Nuclear Information System (INIS)

    Song, C.W.; Kim, T.H.; Khan, F.M.; Kersey, J.H.; Levitt, S.H.

    1981-01-01

    Total body irradiation (TBI) followed by bone marrow transplantation is being used in the treatment of malignant or non-malignant hemopoietic disorders. It has been believed that the ability of hemopoietic cells to repair sublethal radiation damage is negligible. Therefore, several schools of investigators suggested that TBI in a single exposure at extremely low dose rate (5 rad/min) over several hours, or in several fractions in 2-3 days, should yield a higher therapeutic gain, as compared with a single exposure at a high dose rate (26 rad/min). We reviewed the existing data in the literature, in particular, the response of hemopoietic cells to fractionated doses of irradiation and found that the repair capacity of both malignant and non-malignant hemopoietic cells might be greater than has been thought. It is concluded that we should not underestimate the ability of hemopoietic cells to repair sublethal radiation damage in using TBI

  10. Comparison of single, fractionated and hyperfractionated irradiation on the development of normal tissue damage in rat lung

    International Nuclear Information System (INIS)

    Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

    1985-01-01

    The effect of fractionated thoracic irradiation on the development of normal tissue damage in rats was compared to that produced by single doses. Animals received a single dose of 15 Gy, 30 Gy in 10 daily fractions of 3 Gy each (fractionation), or 30 Gy in 30 fractions of 1 Gy each 3 times a day (hyperfractionation). The treatments produced minimal lethality since a total of only 6 animals died between days 273 and 475 after the initiation of treatment, with no difference in survival observed between the control and any of the 3 treated groups. Despite the lack of lethality, evidence of lung damage was obtained by histological examination. Animals that had received either single doses or fractionated doses had more of the pulmonary parenchyma involved than did animals that had received hyperfractionated doses. The authors conclude that, in the rat lung model, a total radiation dose of 30 Gy fractionated over 14 days produces no more lethality nor damage to lung tissue than does 15 Gy delivered as a single dose. However, long-term effects as evidenced by deposits of collagen and development of fibrosis are significantly reduced by hyperfractionation when compared to single doses and daily fractionation

  11. New possibilities of the isotope distribution examination in irradiated absorbing materials using secondary ion mass spectrometry method

    International Nuclear Information System (INIS)

    Goncharenko, Y. D.; Evseev, L.A.; Risovany, V.D.

    2005-01-01

    The SIMS technique (with using a linear analysis and 2D surface imaging) has been to measure the radial distribution of the boron isotope ratio in the boron carbide pellets irradiated in the fast reactor. It was revealed that a radial distribution of isotope ratio in the boron carbide pellets is significantly different after irradiation in fast and thermal reactors. It was showed the advisability of using ion images for such examinations. (Author)

  12. Mutation induction in haploid yeast after split-dose radiation-exposure. I. Fractionated UV-irradiation.

    Science.gov (United States)

    Schenk, K; Zölzer, F; Kiefer, J

    1989-01-01

    Mutation induction was investigated in wild-type haploid yeast Saccharomyces cerevisiae after split-dose UV-irradiation. Cells were exposed to fractionated 254 nm-UV-doses separated by intervals from 0 to 6 h with incubation either on non-nutrient or nutrient agar between. The test parameter was resistance to canavanine. If modifications of sensitivity due to incubation are appropriately taken into account there is no change of mutation frequency.

  13. Codex general standard for irradiated foods and recommended international code of practice for the operation of radiation facilities used for the treatment of foods

    International Nuclear Information System (INIS)

    1990-06-01

    The FAO/WHO Codex Alimentarius Commission was established to implement the Joint FAO/WHO Food Standards Programme. The purpose of this programme is to protect the health of consumers and to ensure fair practices in the food trade. At its 15th session, held in July 1983, the Commission adopted a Codex General Standard for Irradiated Foods and a Recommended International Code of Practice for the Operation of Radiation Facilities used for the Treatment of Foods. This Standard takes into account the recommendations and conclusions of the Joint FAO/IAEA/WHO Expert Committees convened to evaluate all available data concerning the various aspects of food irradiation. This Standard refers only to those aspects which relate to the processing of foods by ionising energy. The Standard recognizes that the process of food irradiation has been established as safe for general application to an overall average level of absorbed dose of 10 KGy. The latter value shold not be regarded as a toxicological upper limit above which irradiated foods become unsafe; it is simply the level at or below which safety has been established. The Standard provides certain mandatory provisions concerning the facilities used and for the control of the process in the irradiation plants. The present Standard requires that shipping documents accompanying irradiated foods moving in trade should indicate the fact of irradiation. The labelling of prepackaged irradiated foods intended for direct sale to the consumer is not covered in this Standard

  14. Codex general standard for irradiated foods and recommended international code of practice for the operation of radiation facilities used for the treatment of foods

    International Nuclear Information System (INIS)

    1984-01-01

    The FAO/WHO Codex Alimentarius Commission was established to implement the Joint FAO/WHO Food Standards Programme. The purpose of this programme is to protect the health of consumers and to ensure fair practices in the food trade. At its 15th session, held in July 1983, the Commission adopted a Codex General Standard for Irradiated Foods and a Recommended International Code of Practice for the Operation of Radiation Facilities used for the Treatment of Foods. This Standard takes into account the recommendations and conclusions of the Joint FAO/IAEA/WHO Expert Committees convened to evaluate all available data concerning the various aspects of food irradiation. This Standard refers only to those aspects which relate to the processing of foods by ionising energy. The Standard recognizes that the process of food irradiation has been established as safe for general application to an overall average level of absorbed dose of 10 kGy. The latter value should not be regarded as a toxicological upper limit above which irradiated foods become unsafe; it is simply the level at or below which safety has been established. The Standard provides certain mandatory provisions concerning the facilities used and for the control of the process in the irradiation plants. The present Standard requires that shipping documents accompanying irradiated foods moving in trade should indicate the fact of irradiation. The labelling of prepackaged irradiated foods intended for direct sale to the consumer is not covered in this Standard

  15. Hazard evaluation of The International Fusion Materials Irradiation Facility

    Energy Technology Data Exchange (ETDEWEB)

    Burgazzi, Luciano [ENEA-Centro Ricerche ' Ezio Clementel' , Advanced Physics Technology Division, Via Martiri di Monte Sole, 4, 40129 Bologna (Italy)]. E-mail: burgazzi@bologna.enea.it

    2005-01-15

    The International Fusion Materials Irradiation Facility (IFMIF) is aimed to provide an intense neutron source by a high current deuteron linear accelerator and a high-speed lithium flow target, for testing candidate materials for fusion. Liquid lithium is being circulated through a loop and is kept at a temperature above its freezing point. In the frame of the design phase called Key Element technology Phase (KEP), jointly performed by an international team to verify the most important risk factors, safety assessment of the whole plant has been required in order to identify the hazards associated with the plant operation. This paper discusses the safety assessments that were performed and their outcome: Failure Mode and Effect Analysis (FMEA) approach has been adopted in order to accomplish the task. Main conclusions of the study is that, on account of the safety and preventive measures adopted, potential plant related hazards are confined within the IFMIF security boundaries and great care must be exercised to protect workers and site personnel from operating the plant. The analysis has provided as a result a set of Postulated Initiating Events (PIEs), that is off-normal events, that could result in hazardous consequences for the plant, together with the total frequency and the list of component failures which could induce the PIE: this assures the exhaustive list of major initiating events of accident sequences, helpful to the further accident sequence analysis phase. Finally, for each one of the individuated PIEs, the evaluation of the accident evolution, in terms of effects on the plant and relative countermeasures, has allowed to verify that adequate measures are being taken both to prevent the accident occurrence and to cope with the accident consequences, thus assuring the fulfilment of the safety requirements.

  16. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    International Nuclear Information System (INIS)

    Jimenez V, Reina A.

    2007-01-01

    The International Commission of Radiation Units (ICRU) has established through the years, a discrimination system regarding the security levels on the prescription and administration of doses in radiation treatments (Radiotherapy, Brach therapy, Nuclear Medicine). The first level is concerned with the prescription and posterior assurance of dose administration to a point of interest (POI), commonly located at the geometrical center of the region to be treated. In this, the effects of radiation around that POI, is not a priority. The second level refers to the dose specifications in a particular plane inside the patient, mostly the middle plane of the lesion. The dose is calculated to all the structures in that plane regardless if they are tumor or healthy tissue. In this case, the dose is not represented by a point value, but by level curves called 'isodoses' as in a topographic map, so you can assure the level of doses to this particular plane, but it also leave with no information about how this values go thru adjacent planes. This is why the third level is referred to the volumetrical description of doses so these isodoses construct now a volume (named 'cloud') that give us better assurance about tissue irradiation around the volume of the lesion and its margin (sub clinical spread or microscopic illness). This work shows how this evolution has resulted, not only in healthy tissue protection improvement but in a rise of tumor control, quality of life, better treatment tolerance and minimum permanent secuelae

  17. Effect of irradiation in design of LMFBR internals

    International Nuclear Information System (INIS)

    Tavassoli, A.A.; Cowan, A.; Vries, M. de; Heesen, E.

    1990-01-01

    Internal structures of nuclear power reactors are essentially made with the austenitic stainless steels Types 304L and 316L. In service these structures receive low to moderate neutron doses. In this paper, the work undertaken by the European Fast Breeder Working Group is reviewed. Conclusions drawn to this date are presented and tentative reduction factors to be used in design are discussed in terms of the number of displacements per atom (dpa) and the quantity of helium generated in the steel (appm He). For the lower core structure which operates at about 400 0 C existing design rules can be used for parts which are subjected to less than 2 dpa despite a reduction in ductility and toughness which occurs above about 0.8 dpa. For the above core structure which operates at about 550 0 C interim and rather conservative stress reduction factors are proposed which can become effective at helium levels as low as 10 -4 appm. Particular attention is paid to: - irradiation temperature, - neutron flux and fluence, - steel type and grade, - heat treatment and boron distribution, - weld metal composition and procedure (TIG,MMA,...), to ensure that service conditions are represented as closely as possible

  18. Lethal mutation of internal irradiation brown planthopper (Nilaparvita lugens Stal)

    International Nuclear Information System (INIS)

    Wahid, R.A.

    1988-01-01

    The moulting IVth of BPH nympha were irradiated internally with radiophosphorous 32-P 1 uCi/ml, 10 uCi/ml, 50 uCi/ml, 100 uCi/ml, and 500 uCi/ml concentrations respectivelly. An observation was carried out to determines heredity of hopper sterilities from the mating groups of R male x N female, R male x R female, and N male x R female. The 32-P concentration below of 50 uCi/ml seemed to be the substerile dose, however, the dominant lethal mutation has been visually shown by R male x R female F1 mating group. The hereditary lines of F1, F2, F3, and F4 of the hopper sterilities wich were indicated by the nympha hatch ability have some significant correlations (r1= -0.77, r2= -0.92, r3= -0.93 and r4= -0.85). Thus, the resesif lethal mutations visually showed by F3 and F4 from all of the 100 uCi/ml and 50 uCi/ml treated groups. (author). 10 refs, 2 figs, 2 tabs

  19. Early reoxygenation in tumors after irradiation: Determining factors and consequences for radiotherapy regimens using daily multiple fractions

    International Nuclear Information System (INIS)

    Crokart, Nathalie; Jordan, Benedicte F.; Baudelet, Christine; Ansiaux, Reginald; Sonveaux, Pierre; Gregoire, Vincent; Beghein, Nelson; Wever, Julie de; Bouzin, Caroline; Feron, Olivier; Gallez, Bernard

    2005-01-01

    Purpose: To characterize changes in the tumor microenvironment early after irradiation and determine the factors responsible for early reoxygenation. Methods and Materials: Fibrosarcoma type II (FSaII) and hepatocarcinoma transplantable liver tumor tumor oxygenation were determined using electron paramagnetic resonance oximetry and a fiberoptic device. Perfusion was assessed by laser Doppler, dynamic contrast-enhanced MRI, and dye penetration. Oxygen consumption was determined by electron paramagnetic resonance. The interstitial fluid pressure was evaluated by the wick-in-needle technique. Results: An increase in oxygen partial pressure was observed 3-4 h after irradiation. This increase resulted from a decrease in global oxygen consumption and an increase in oxygen delivery. The increase in oxygen delivery was due to radiation-induced acute inflammation (that was partially inhibited by the antiinflammatory agent diclofenac) and to a decrease in interstitial fluid pressure. The endothelial nitric oxide synthase pathway, identified as a contributing factor at 24 h after irradiation, did not play a role in the early stage after irradiation. We also observed that splitting a treatment of 18 Gy into two fractions separated by 4 h (time of maximal reoxygenation) had a greater effect on tumor regrowth delay than when applied as a single dose. Conclusion: Although the cell cycle redistribution effect is important for treatment protocols using multiple daily radiation fractions, the results of this work emphasize that the oxygen effect must be also considered to optimize the treatment strategy

  20. Effects of bone marrow or mesenchymal stem cell transplantation on oral mucositis (mouse) induced by fractionated irradiation

    International Nuclear Information System (INIS)

    Schmidt, M.; Haagen, J.; Noack, R.; Siegemund, A.; Gabriel, P.; Doerr, W.

    2014-01-01

    Oral mucositis is a severe and dose limiting early side effect of radiotherapy for head-and-neck tumors. This study was initiated to determine the effect of bone marrow- and mesenchymal stem cell transplantation on oral mucositis (mouse tongue model) induced by fractionated irradiation. Daily fractionated irradiation (5 x 3 Gy/week) was given over 1 (days 0-4) or 3 weeks (days 0-4, 7-11, 14-18). Each protocol was terminated (day 7 or 21) by graded test doses (5 dose groups, 10 animals each) in order to generate complete dose-effect curves. The incidence of mucosal ulceration, corresponding to confluent mucositis grade 3 (RTOG/EORTC), was analyzed as the primary, clinically relevant endpoint. Bone marrow or mesenchymal stem cells were transplanted intravenously at various time points within these fractionation protocols. Transplantation of 6 x 10 6 , but not of 3 x 10 6 bone marrow stem cells on day -1, +4, +8, +11 or +15 significantly increased the ED 50 values (dose, at which an ulcer is expected in 50% of the mice); transplantation on day +2, in contrast, was ineffective. Mesenchymal stem cell transplantation on day -1, 2 or +8 significantly, and on day +4 marginally increased the ED 50 values. Transplantation of bone marrow or mesenchymal stem cells has the potential to modulate radiation-induced oral mucositis during fractionated radiotherapy. The effect is dependent on the timing of the transplantation. The mechanisms require further investigation. (orig.)

  1. A computational model for heterogeneous heating during pulsed laser irradiation of polymers doped with light-absorbing microparticles

    DEFF Research Database (Denmark)

    Marla, Deepak; Zhang, Yang; Jabbaribehnam, Mirmasoud

    2016-01-01

    characteristics. This work presents a study based on a computational model of laser heating of polymer doped with light-absorbing microparticles accounting for the heterogeneous nature of heating. The work aims at gaining a fundamental insight into the nature of the heating process and to understand the role......Doping of polymers with light-absorbing microparticles to increase their optical properties is a commonly used pre-treatment technique in laser processing of polymers. The presence of these particles plays an important role during laser heating of the polymer that influences its surface...... of microparticles. The results suggest that apart from the laser intensity and pulse duration, the properties of the microparticles including their size and distribution also play an important role during the laser heating of polymers....

  2. Effect of single dose, fractionated, and hyperfractionated trunk irradiation on weight gain, respiration frequency, and survival in rats

    International Nuclear Information System (INIS)

    Kimler, B.F.; Giri, P.G.S.; Giri, U.P.; Cox, G.G.

    1986-01-01

    It is concluded that, in this rat trunk irradiation model, fractionation of a single dose into two equal doses separated by 4-6 h produced a sparing effect of approx. 5Gy as measured by delay in weight gain; approx. 4Gy as measured by increased respiration frequency; and approx. 6Gy as measured by survival. Fractionation into daily doses or hyperfractionation into twice-daily doses permitted an approximate doubling of the dose required for the same suppression of weight gain. For the respiration rates and survival endpoints, fractionation or hyperfractionation produced an even greater sparing effect since there was no increase in the respiration frequency at twice the doses that would produce changes if delivered within a few hours; and since essentially no lethality was observed at twice the doses that would kill 70%-100% of animals if delivered in one day. (UK)

  3. Influence of the timing of a concomitant boost during fractionated irradiation of rat rhabdomyosarcoma R1H

    International Nuclear Information System (INIS)

    Dubben, H.H.; Beck-Bornholdt, H.P.

    1993-01-01

    Rhabdomyosarcomas R1H of the rat (WAG/Rij) were treated using fractionation schedules including a boost. The total dose was 60 Gy. Overall treatment time was 6 weeks. Four different boost schedules were applied: A single dose boost (12.15 Gy) at the last day of treatment, a single dose boost (12.15 Gy) at the first day of treatment, a schedule including the boost in 7 fractions during the first week, and a schedule including the boost in 10 fractions during the first week of treatment. A standard schedule with 30 fractions of 2 Gy without a boost was used for comparison. Initially accelerated schedules, i.e. those with a boost at start of treatment, revealed higher effect on tumour parenchyma as monitored by local control rate and net growth delay. This could be due to a decrease of radio-sensitivity, that is, an increase of the hypoxic fraction of clonogenic tumour cells during fractionated irradiation. (orig.)

  4. Quality assurance program of a respiratory gating irradiation system based on external and internal fiducial markers; Programa de garantia de calidad de un sistema de irradiacion con control respiratorio basado en marcadores fiduciales externos e internos

    Energy Technology Data Exchange (ETDEWEB)

    Zucca Aparicio, D.; Perez Moreno, J. M.; Fernandez Leton, P.; Garcia Ruiz-Zorrilla, J.; Minambres Moro, A.

    2011-07-01

    Respiratory Gating involves the administration of radiation during treatment delivery within a particular portion of the patients breathing cycle, so the absorbed dose administration with respiratory control techniques requires specific quality control to ensure the correctness of the delivered dose. The establishment of a Quality Control Program (QC) is proposed for the Respiratory Gating based techniques in order to have a better understanding of how this system works and to know its associated dosimetric impact. The influence of the CT acquisition under respiratory motion conditions has been analyzed for the treatment isocenter localization, using internal and external fiducial markers with IGRT techniques that allow the correlation of the isocenter positioning with the phase of the respiratory cycle. Radiation delivery in the presence of intra fraction organ motion causes an averaging or blurring of the static dose distribution over the path of motion increasing the beam penumbra of the radiation field and reducing the therapeutic region when the irradiation is not breath controlled. The feasibility of intensity modulated treatments (IMRT) for both static and dynamic techniques, managed by respiratory control has been tested, demonstrating the possibility of synchronizing the movement of the leaves in the microfluorimeter collimator (mMLC) with the gated beam irradiation. (Author) 45 refs.

  5. Hourly distributions of the diffuse fraction of global solar irradiation in Cordoba (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Posadillo, R.; Lopez Luque, R. [Grupo de Investigacion de Fisica para las Energias y Recursos Renovables, Dpto. de Fisica Aplicada/UCO, Edificio C2 Campus de Rabanales, 14071 Cordoba (Spain)

    2009-02-15

    Hourly global irradiations on tilted planes are required for dimensioning PV systems. However, for most sites, only global irradiations on a horizontal plane are available, and, given that to calculate the global irradiation on inclined planes the first step is to determine the diffuse component and this is not collected, we have studied the behaviour of the diffuse component on an hourly basis. Most parametrization models for the derivation of hourly diffuse irradiance from hourly global irradiance involve the clearness index, a parameter that implicitly includes solar altitude. The present paper has focused on the possibility of also including ''mean solar altitude anti {alpha}'' explicitly as a parameter in addition to the clearness index. Several analytical models are proposed, validated and compared here, using solar data collected on our station located in Cordoba (Spain). (author)

  6. Hourly distributions of the diffuse fraction of global solar irradiation in Cordoba (Spain)

    International Nuclear Information System (INIS)

    Posadillo, R.; Lopez Luque, R.

    2009-01-01

    Hourly global irradiations on tilted planes are required for dimensioning PV systems. However, for most sites, only global irradiations on a horizontal plane are available, and, given that to calculate the global irradiation on inclined planes the first step is to determine the diffuse component and this is not collected, we have studied the behaviour of the diffuse component on an hourly basis. Most parametrization models for the derivation of hourly diffuse irradiance from hourly global irradiance involve the clearness index, a parameter that implicitly includes solar altitude. The present paper has focused on the possibility of also including 'mean solar altitude α-bar' explicitly as a parameter in addition to the clearness index. Several analytical models are proposed, validated and compared here, using solar data collected on our station located in Cordoba (Spain)

  7. First-principles investigation of neutron-irradiation-induced point defects in B4C, a neutron absorber for sodium-cooled fast nuclear reactors

    Science.gov (United States)

    You, Yan; Yoshida, Katsumi; Yano, Toyohiko

    2018-05-01

    Boron carbide (B4C) is a leading candidate neutron absorber material for sodium-cooled fast nuclear reactors owing to its excellent neutron-capture capability. The formation and migration energies of the neutron-irradiation-induced defects, including vacancies, neutron-capture reaction products, and knocked-out atoms were studied by density functional theory calculations. The vacancy-type defects tend to migrate to the C–B–C chains of B4C, which indicates that the icosahedral cage structures of B4C have strong resistance to neutron irradiation. We found that lithium and helium atoms had significantly lower migration barriers along the rhombohedral (111) plane of B4C than perpendicular to this plane. This implies that the helium and lithium interstitials tended to follow a two-dimensional diffusion regime in B4C at low temperatures which explains the formation of flat disk like helium bubbles experimentally observed in B4C pellets after neutron irradiation. The knocked-out atoms are considered to be annihilated by the recombination of the close pairs of self-interstitials and vacancies.

  8. Influence of chronic internal and acute external irradiations on the critical tissues of plants

    International Nuclear Information System (INIS)

    Kostyuk, O.P.; Ryasnenko, N.A.; Grodzins'kij, D.M.

    1998-01-01

    Peculiarities of chronic internal and acute external irradiations of the critical (as for irradiation influence) plants part, meristem, are studied. In particular, the investigation has aimed to evaluate the level of doses, accumulated by plant tissues, of the chronic internal irradiation from radiocaesium incorporated by them, and to compare its possible effect to one caused by the acute external irradiation. It is shown that the effects of both chronic and acute irradiations have similar features, and it is assumed that they have the very same mechanisms. We think that such a parameter of the plant ability to accumulate radiocaesium as the ratio of its content in a root tip and in the whole root system is a very sensible and useful criterion to estimate the irradiation influence on plants

  9. On the definition of absorbed dose

    International Nuclear Information System (INIS)

    Grusell, Erik

    2015-01-01

    Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before. - Highlights: • A stringent definition of absorbed dose is given. • This requires the definition of an irradiation and a suitable probability space. • A stringent definition is important for an understanding of the concept absorbed dose

  10. Expression profiling of murine lung 70 days following exposure to fractionated or acute dose of 1.0 Gy 56Fe- particle irradiation

    Data.gov (United States)

    National Aeronautics and Space Administration — Irradiation of the K-rasLA1 mouse model with a fractionated dose of 1.0Gy 56Fe- particles increases the incidence of invasive carcinoma compared to unirradiated...

  11. Effect of lithium carbonate on leukocyte number after influence of ionizing radiation. 3. Influence of lithium carbonate on peripheral leukocytes after fractionated caudal half-body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, H.; Saul, G.; Kehrberg, G. (Humboldt-Universitaet, Berlin (German Democratic Republic). Bereich Medizin (Charite))

    1985-01-01

    Fractionated half-body irradiation of rats resulted in leukopenia of the peripheral blood. The decrease of leukocytes was smaller in animals pretreated with an orally administered dose of lithium carbonate for 14 days.

  12. Decreased repopulation as well as increased reoxygenation contribute to the improvement in local control after targeting of the EGFR by C225 during fractionated irradiation.

    NARCIS (Netherlands)

    Krause, M.; Ostermann, G.; Petersen, C.; Yaromina, A.; Hessel, F.; Harstrick, A.; Kogel, A.J. van der; Thames, H.D.; Baumann, M.

    2005-01-01

    BACKGROUND AND PURPOSE: Inhibition of repopulation and enhanced reoxygenation has been suggested to contribute to improvement of local tumour control after fractionated irradiation combined with inhibitors of the epidermal growth factor receptor (EGFR). The present study addresses this hypothesis in

  13. Effect of fractionated versus unfractionated total body irradiation on the growth of the BN acute myelocytic leukemia

    International Nuclear Information System (INIS)

    Hagenbeek, A.; Martens, A.C.M.

    1981-01-01

    The efficacy of various total body irradiation (TBI) regimens prior to bone marrow transplantation was evaluated in a rat model for acute myelocytic leukemia (Dq = 85.1 cGy gamma ; N = 3.7). Using high dose rate gamma-irradiation (115 cGy/min), fractionated TBI with large total daily doses (400 to 600 cGy), either given as acute doses or as split doses at 8 hr intervals, was most effective. Split doses (2 fractions per day) offered no additional advantage. At the most, a 4 log leukemic cell kill was induced. No lethal toxicity was observed. Nine-hundred cGy flash TBI had a similar anti-tumor effect, but with this regimen almost half of the rats died from radiation-induced toxicity (lungs and gastro-intestinal tract). The results are explained in terms of differences between normal and leukemic cells as regards (a) repair of sublethal damage; and (b) repopulation. Low dose rate continuous gamma-irradiation (0.26 cGy/min) with total doses ranging from 900 to 2000 cGy was also quite effective. Maximally a 4 log cell kill was obtained. With 2000 cGy, 50% of the rats died from the gastro-intestinal tract-syndrome. In addition to the major role played by chemotherapy, TBI is mainly of importance in sterilizing the various sanctuaries in the body which contain leukemic cells anatomically resistant to most cytostatic agents

  14. Low-dose X-irradiation of adjuvant-induced arthritis in rats. Efficacy of different fractionation schedules

    International Nuclear Information System (INIS)

    Liebmann, A.; Hindemith, M.; Jahns, J.; Kamprad, F.; Hildebrandt, G.; Madaj-Sterba, P.; Weisheit, S.

    2004-01-01

    Background and purpose: low-dose radiotherapy is widely accepted as a very effective treatment option for inflammatory symptoms associated with painful degenerative joint disorders. Radiation doses and fractionation schedules in practical use are empirical and mainly based on clinical observations. Experimental data are rare. The efficacy of low-dose X-irradiation on adjuvant induced arthritis in rats using different fractionation schemes was investigated in vivo, in order to explore whether there is a dose and fractionation dependence. Material and methods: adjuvant arthritis in female lewis rats (n = 128) was induced by intradermal injection of heat-inactivated Mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham-irradiated (group 1: days 10-14; group 2: days 15-19; group 3: days 22-26) or X-irradiated with either 5 x 1.0 Gy (group 4: days 10-14; group 6: days 15-19; group 8: days 22-26; group 10: days 10, 12, 14, 16, and 18) or 5 x 0.5 Gy (group 5: days 10-14; group 7: days 15-19; group 9: days 22-26; group 11: days 10, 12, 14, 16, and 18; group 12: days 10-14 and 22-26). The clinical parameters arthritis score (AS), hind paw volume (HPV), and body weight were determined. Results: a significant decrease of the clinical arthritis parameters was observed following 5 x 0.5 Gy or 5 x 1.0 Gy during the acute maximum of the inflammatory response (days 15-19). The most pronounced treatment effect was reached after two daily fractionated series of 5 x 0.5 Gy with an early treatment onset (days 10-14) and repetition in interval (days 22-26). After the application of 5 x 1.0 Gy on days 10-14 or in a protracted scheme (days 10, 12, 14, 16, and 18), only a nonsignificant positive trend could be detected. Daily fractionated X-irradiation in the chronic phase of adjuvant arthritis (days 22-26) did not show any positive clinical effect. Conclusion: low-dose radiotherapy is able to prevent a full-blown arthritic reaction if given during the florid phase of

  15. Worldwide status of food irradiation and the role of IAEA and other international organizations

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1988-01-01

    While there has been an increasing interest in introducing irradiation for preservation and decontamination of food by national authorities and food industry, this technology has generated wide public debate in view of its perceived association with nuclear technology. The purpose of this paper is twofold: (1) to provide objectivity to the application of irradiation for food processing and (2) to project future trends of this technology. Irradiation appears to offer the most viable alternative to the existing technologies in quarantine treatment, hygienic quality of foods, reduction of food losses, and increase in market demand for fresh foods. Current limitations of food irradiation are discussed in terms of technical aspects, infrastructure and economics, consumer concerns, and harmonization of national regulations. Commercial applications have been reported in 19 countries. It is estimated that the total production of irradiated foods world-wide amounted to approximately 500,000 tons per annum. To ensure an effective implementation of the technology on a global basis, FAO and WHO have collaborated closely with the IAEA. An International Consultative Group on Food Irradiation was established under the aegis of FAO, IAEA, and WHO in May 1984. These organizations play an important role in training, technology transfer, developing guidelines on specific applications of food irradiation, international register of food irradiation facilities, acceptance and international trade in irradiated foods, and public information. (Namekawa, K.)

  16. Worldwide status of food irradiation and the role of IAEA and other international organizations

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P.

    1988-04-01

    While there has been an increasing interest in introducing irradiation for preservation and decontamination of food by national authorities and food industry, this technology has generated wide public debate in view of its perceived association with nuclear technology. The purpose of this paper is twofold: (1) to provide objectivity to the application of irradiation for food processing and (2) to project future trends of this technology. Irradiation appears to offer the most viable alternative to the existing technologies in quarantine treatment, hygienic quality of foods, reduction of food losses, and increase in market demand for fresh foods. Current limitations of food irradiation are discussed in terms of technical aspects, infrastructure and economics, consumer concerns, and harmonization of national regulations. Commercial applications have been reported in 19 countries. It is estimated that the total production of irradiated foods world-wide amounted to approximately 500,000 tons per annum. To ensure an effective implementation of the technology on a global basis, FAO and WHO have collaborated closely with the IAEA. An International Consultative Group on Food Irradiation was established under the aegis of FAO, IAEA, and WHO in May 1984. These organizations play an important role in training, technology transfer, developing guidelines on specific applications of food irradiation, international register of food irradiation facilities, acceptance and international trade in irradiated foods, and public information. (Namekawa, K.).

  17. The occurrence of recruitment supported from the finding of an increase in radiosensitivity of quiescent cells in solid tumors after fractionated irradiation with X-rays

    International Nuclear Information System (INIS)

    Masunaga, Shinichiro; Ono, Koji; Kinashi, Yuko; Suzuki, Minoru; Akaboshi, Mitsuhiko

    1998-01-01

    We examined the behavior of quiescent cells in solid tumors irradiated twice at various intervals with X-rays, using our recently developed method for selectively detecting the response of quiescent cells in solid tumors. To determine the labeling indices of tumors at the second irradiation, each mouse group included mice that were continuously administered BrdU until just before the second irradiation using mini-osmotic pumps which had been implanted before the first irradiation. Radiosensitivity of total tumor cells at the second irradiation decreased in proportion to the increase in interval time. However, radiosensitivity of quiescent cells was raised with increase in the interval time. In addition, the labeling index at the second irradiation was higher than that at the first irradiation. These findings supported the occurrence of recruitment from quiescent to proliferating state during fractionated irradiation. (author)

  18. Decreased repopulation as well as increased reoxygenation contribute to the improvement in local control after targeting of the EGFR by C225 during fractionated irradiation

    International Nuclear Information System (INIS)

    Krause, Mechthild; Ostermann, Gernot; Petersen, Cordula; Yaromina, Ala; Hessel, Franziska; Harstrick, Andreas; Kogel, Albert J van der; Thames, Howard D; Baumann, Michael

    2005-01-01

    Background and purpose: Inhibition of repopulation and enhanced reoxygenation has been suggested to contribute to improvement of local tumour control after fractionated irradiation combined with inhibitors of the epidermal growth factor receptor (EGFR). The present study addresses this hypothesis in FaDu human squamous cell carcinoma. For this tumour model marked repopulation and incomplete reoxygenation during fractionated irradiation has previously been demonstrated. Furthermore, the anti-EGFR monoclonal antibody C225 has been shown to significantly improve the results of fractionated irradiation in this tumour. Materials and methods: FaDu tumours in nude mice were irradiated with 18 fractions in 18 days (18f/18d) or 18 fractions in 36 days (18f/36d). Three Gy fractions were given either under ambient or under clamp hypoxic conditions. C225 or carrier was applied four times during the course of treatment. Fractionated irradiations were followed by graded top-up doses to obtain complete dose-response curves for local tumour control. Tumour control dose 50% (TCD 50 ) was determined at day 120 after end of treatment. Results: Significant repopulation and reoxygenation occurred during fractionated irradiation of FaDu tumours (P-values between 0.028 and 50 for 18f/36d under ambient conditions (P=0.04). Bootstrap analysis revealed decreased repopulation and increased reoxygenation after application of C225 (P=0.06 for the combined effect). This was further corroborated by a significant effect of C225 on the 'repopulated' dose under ambient conditions which is influenced by both, reoxygenation and repopulation (P=0.012). Conclusions: Our study provides evidence that both decreased repopulation as well as increased reoxygenation contribute to the improvement of local control after targeting of EGFR by C225 during fractionated irradiation of FaDu tumours

  19. Arrested neuronal proliferation and impaired hippocampal function following fractionated brain irradiation in the adult rat

    DEFF Research Database (Denmark)

    Madsen, Torsten Meldgaard; Kristjansen, P.E.G.; Bolwig, Tom Gert

    2003-01-01

    irradiation blocked the formation of new neurons in the dentate gyrus of the hippocampus. At different time points after the termination of the irradiation procedure, the animals were tested in two tests of short-term memory that differ with respect to their dependence on hippocampal function. Eight and 21...... that blocked neurogenesis contributes to the reported deleterious side effects of this treatment, consisting of memory impairment, dysphoria and lethargy....

  20. Estimation of the fraction of absorbed photosynthetically active radiation (fPAR) in maize canopies using LiDAR data and hyperspectral imagery.

    Science.gov (United States)

    Qin, Haiming; Wang, Cheng; Zhao, Kaiguang; Xi, Xiaohuan

    2018-01-01

    Accurate estimation of the fraction of absorbed photosynthetically active radiation (fPAR) for maize canopies are important for maize growth monitoring and yield estimation. The goal of this study is to explore the potential of using airborne LiDAR and hyperspectral data to better estimate maize fPAR. This study focuses on estimating maize fPAR from (1) height and coverage metrics derived from airborne LiDAR point cloud data; (2) vegetation indices derived from hyperspectral imagery; and (3) a combination of these metrics. Pearson correlation analyses were conducted to evaluate the relationships among LiDAR metrics, hyperspectral metrics, and field-measured fPAR values. Then, multiple linear regression (MLR) models were developed using these metrics. Results showed that (1) LiDAR height and coverage metrics provided good explanatory power (i.e., R2 = 0.81); (2) hyperspectral vegetation indices provided moderate interpretability (i.e., R2 = 0.50); and (3) the combination of LiDAR metrics and hyperspectral metrics improved the LiDAR model (i.e., R2 = 0.88). These results indicate that LiDAR model seems to offer a reliable method for estimating maize fPAR at a high spatial resolution and it can be used for farmland management. Combining LiDAR and hyperspectral metrics led to better performance of maize fPAR estimation than LiDAR or hyperspectral metrics alone, which means that maize fPAR retrieval can benefit from the complementary nature of LiDAR-detected canopy structure characteristics and hyperspectral-captured vegetation spectral information.

  1. Correlation between radiological, scintigraphic and histological changes in bone in rabbits following irradiation with single and fractionated doses

    International Nuclear Information System (INIS)

    Burgener, F.A.; King, M.A.; Weber, D.A.

    1979-01-01

    In the left hind legs of eight rabbits were irradiated with 1,750 rad in a single dose or with 4,650 rad divided over a period of three weeks. These animals, as well as four who had not been irradiated, were examined periodically radiologically and with 99 mTechnetium pyrophosphate scintigrams during one year. No difference could be detected between the results of the single and fractionated doses. Scintigraphically there was a biphasic increase in uptake, the first peak co-inciding with the irradiation and of vascular origin, whereas the second peak occured at four months and was due to a change in bone metabolism. At the end of a year uptake in the irradiated limb was slightly reduced. The earliest radiological changes were found after six months, at the end of the second scintigraphic peak; they consisted of coarsening and blurring of the trabeculae, non-homogeneous spotty mineralisation and endosteal scalloping. Six animals developed a radiation-induced bone sarcoma, first demonstrated either by scintigraphy or radiology depending on its histology. The value of combining radiological and scintigraphic examinations for the early detection of post-radiation abnormalities is stressed. (orig.) [de

  2. Expression of P-glycoprotein and multidrug resistance associated protein in Ehrlich ascites tumor cells after fractionated irradiation

    DEFF Research Database (Denmark)

    Nielsen, D; Maare, C; Eriksen, J

    2001-01-01

    PURPOSE: To characterize irradiated murine tumor cells with respect to drug resistance, drug kinetics, and ATPase activity, and to evaluate the possible role of P-glycoprotein (PGP) and murine multidrug resistance associated protein (Mrp1) in the drug-resistant phenotype of these cells. METHODS...... AND MATERIALS: Sensitive Ehrlich ascites tumor cells (EHR2) were in vitro exposed to fractionated irradiation (60 Gy). Western blot analysis was performed for determination of PGP and Mrp1, reverse transcriptase-polymerase chain reaction (RT-PCR) for determination of mdr1a + b mRNA, and semiquantitative RT......-PCR for Mrp1 mRNA. The clonogenic assay was applied to investigate sensitivity, whereas the steady-state drug accumulation of daunorubicin (DNR), 3H-vincristine (VCR), and 3H-etoposide (VP16) was measured by spectrofluorometry and scintillation counting, respectively. For determining of ATPase activity...

  3. Experiences of an international trade action with irradiated onions between GDR and Hungary

    International Nuclear Information System (INIS)

    Zachariev, G.; Kiss, I.; Luther, T.; Huebner, G.; Doellstaedt, R.

    1988-01-01

    Extensive work has been carried out in the field of food irradiation in the GDR and Hungary in recent years. The irradiation of onions for sprout inhibition has reached a commercial stage in the GDR of more than 5,000 tons in 1986. The export of onions is the first example of international trade in irradiated food between socialist countries. Experiences of this trade is presented in the paper. Results of quality control of the bulbs (losses in weight an quality) after an intermediate storage period are discussed. Hungarian consumer reactions to irradiated onions is also evaluated. (author)

  4. The indication and the point at issue in total body irradiation (TBI)

    International Nuclear Information System (INIS)

    Kikuchi, Yuzo; Nishino, Shigeo.

    1992-01-01

    The role of radiation in the cause of interstitial pneumonitis (IP) was analysed here. Also optimal dose fractionation was discussed about total absorbed lung dose, dose rate and fractionation in spect of IP. After all optimal time schedule was recommended 3, 4 and 6 fraction of ≤ 4 Gy of fraction size using conventional and hyperfractionated irradiation. In the end the present condition and the point at issue in the irradiation of blood for prevention GVHD were discussed. (author)

  5. International Geographic Variation in Event Rates in Trials of Heart Failure With Preserved and Reduced Ejection Fraction

    DEFF Research Database (Denmark)

    Kristensen, Søren L; Køber, Lars; Jhund, Pardeep S

    2015-01-01

    BACKGROUND: International geographic differences in outcomes may exist for clinical trials of heart failure and reduced ejection fraction (HF-REF), but there are few data for those with preserved ejection fraction (HF-PEF). METHODS AND RESULTS: We analyzed outcomes by international geographic reg...

  6. Reply to: Analysis of the effects of fractionated irradiation to the rat heart (by E. van Rongen)

    International Nuclear Information System (INIS)

    Guttenberger, R.

    1987-01-01

    The applicability of the linear quadratic (LQ) model in the analysis of the data presented by Lauk et al. (Radiotherapy. Oncol. 8: 363-367, 1987) is investigated with the linear regression method of Tucker, by simulating fractionated irradiation experiments on tissues with α/β values varying from 1 to 20, starting from theoretical iso-effect doses. It turns out that the LQ model is unreliable for small (∼ 1) α/β values using the error probability p=0.05 and that the sensitivity of the linear regression method is dependent on the underlying α/β. 3 refs.; 1 table

  7. Low-dose fractionated whole-body irradiation in the treatment of advanced non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Choi, N.C.; Timothy, A.R.; Kaufman, S.D.; Carey, R.W.; Aisenberg, A.C.

    1979-01-01

    Thirty-nine patients with advanced non-Hodgkin's lymphoma (38 patients with lymphocytic lymphoma and 1 patient with mixed lymphocytic and histiocytic lymphoma) were treated by fractionated low dose whole body irradiation (WBI) with a minimum follow-up of 8 months. Twenty-eight patients had no previous treatment and the other 11 patients were in relapse after previous chemotherapy or regional radiotherapy. There were 20 and 19 patients in stages III and IV groups, respectively. The majority of patients (31) had nodular histology; diffuse lymphocytic lymphoma was present in 8 patients (Rappaport criteria) (9). Constitutional symptoms were present in 10 patients. Thirty-three (85%) attained complete remission (CR) with median duration of remission 24 months. Actuarial survival was 78% and 74% at 3 and 4 years. However, relapse free survival was 26% at 3 and 4 years. A prospective randomized trial to compare 10 vs. 15 rad per fraction of fractionated WBI schedules (the same total dose 150 rad) demonstrated no difference in response rate, response duration, and median nadir platelet or WBC counts between the two schedules. Supplement radiotherapy to bulky tumor site prevented local recurrence, but did not influence survival or duration or remission. Major toxicity was thrombocytopenia with median nadir platelet counts 77,000/mm 3 (11,000 to 170,000/mm 3 ). Five of 6 patients with diffuse lymphocytic poorly differentiated lymphoma attained CR. However, their median survival was 30 months which is much shorter than that of nodular lymphoma. Constitutional symptoms and advanced stage (stage IV) were associated with shorter duration of remission. Response of patients in relapse after WBI to subsequent chemotherapy +- local radiotherapy was CR in 50% and PR in 40%. Fractionated whole body irradiation is an excellent systemic induction agent for advanced lymphocytic and mixed lymphoma

  8. Development of label dosimeters and analytical methods to verify absorbed dose in irradiated dried fruits/tree nuts

    International Nuclear Information System (INIS)

    Sattar, Abdus; Ahmad, Anwar; Atta, Shaheen

    2001-01-01

    Density measurements of fresh/dried fruits and tree nuts varied depending upon the package size, type and the nature of the sample. For the development of label dosimeters, the samples of clear PMMA in the thickness range of 410 mm gave a linear response in relation to the irradiation doses (0.125-1.0 kGy) and the optical response was stable almost for 6 months at ambient storage (20-35 deg. C; R.H 40-80%). Flexible polymers (polyethylene and PVC) materials were not found suitable in the dose range of 0.1-3.0 kGy. Subjective evaluation of Sterin indicator, an ISP product from USA, revealed that this new material is generally reliable, however, they were also affected by the doses lower than their threshold values (125 and 300 Gy) as well as exposure to light during storage. The yellow PMMA dosimeter (YLPMMA) developed by China was useful in the range of 125-1000 Gy of gamma radiation. Dose distribution studies of research irradiator at NIFA and a commercial gamma source (PARAS) at Lahore, indicated almost a good dose uniformity in the product containers in each case. Among the analytical methods (thermoluminescence and gas chromatography) the thermoluminescence measurements exhibited clearly reproducible and dose dependent differences between treated (0.5-1.5 kGy) and untreated samples of dried fruits/nuts. (author)

  9. The effects of using of mineral and organic toxin absorbents on broiler performance and internal organs weight in experimental aflatoxicosis

    Directory of Open Access Journals (Sweden)

    Behnam Heidarpour

    2016-04-01

    Full Text Available Introduction The occurrence of mycotoxins in foods and feeds is a problem of major concern in all over the world. Profitability of poultry production can be greatly affected due to the frequency of feed contamination and the detrimental effects of these toxins on the performance. Aflatoxins, a group of closely related and biologically active mycotoxins, are produced by strains of Aspergillus flavus and Aspergillus parasiticus. They commonly occur as natural contaminant of poultry feeds. Domestic animal species such as chickens, ducks, cattle and turkeys consuming sublethal doses of aflatoxins for several days developed a toxic syndrome in which liver damage was the most significant change. The biological effects of aflatoxins could be categorized into two groups, long term and short term effects. Long term effects included chronic toxicity, cancer, birth defects and genetic alterations. Aflatoxins affected all poultry species, although they generally take relatively high levels to cause mortality, low levels can be detrimental if continually fed. Material and Methods This study was conducted to determine the efficacy of mineral, organic toxin absorbents, humic acid and yeast cell wall on performance and internal organs weight of broilers in experimental aflatoxicosis. This study was conducted in a completely randomize design with 432 Ross-308 broilers with 9 treatments, 4 replicates and 12 broilers in each replicate. Treatments included diet without aflatoxin, 2: diet contaminated with aflatoxin, 3: diet contaminated with aflatoxin and supplemented with 0.20 Humic acid, 4: diet contaminated with aflatoxin and supplemented with 0.40 Humic acid, 5: diet contaminated with aflatoxin and supplemented with 0.60 Humic acid, 5: diet contaminated with aflatoxin and supplemented with 0.80 Humic acid, 6: diet contaminated with aflatoxin and supplemented with 0.80 Humic acid, 7: diet contaminated with aflatoxin and supplemented with 1.00 Humic acid, 8: diet

  10. A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for 99mTc-hynic-Tyr3-octreotide Imaging

    International Nuclear Information System (INIS)

    Momennezhad, Mehdi; Nasseri, Shahrokh; Zakavi, Seyed Rasoul; Parach, Ali Asghar; Ghorbani, Mahdi; Asl, Ruhollah Ghahraman

    2016-01-01

    Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of 99m Tc-hydrazinonicotinamide (hynic)-Tyr 3 -octreotide as a SPECT radiotracer. 99m Tc patient-speci@@@@@@c S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors. Each patient underwent multiple whole-body planar scans as well as SPECT imaging over a period of 1-24 h after intravenous injection of 99m hynic-Tyr 3 -octreotide. The patient-specific S values calculated by GATE Monte Carlo code and the corresponding S values obtained by MIRDOSE program differed within 4.3% on an average for self-irradiation, and differed within 69.6% on an average for cross-irradiation. However, the agreement between total organ doses calculated by GATE code and MIRDOSE program for all patients was reasonably well (percentage difference was about 4.6% on an average). Normal and tumor absorbed doses calculated with GATE were slightly higher than those calculated with MIRDOSE program. The average ratio of GATE absorbed doses to MIRDOSE was 1.07 ± 0.11 (ranging from 0.94 to 1.36). According to the results, it is proposed that when cross-organ irradiation is dominant, a comprehensive approach such as GATE Monte Carlo dosimetry be used since it provides more reliable dosimetric results

  11. Differential cisplatin responses in human carcinoma cell lines pre-exposed to fractionated X-irradiation

    International Nuclear Information System (INIS)

    Dempke, W.C.M.; Hosking, L.K.; Shellard, S.A.; Hill, B.T.

    1991-01-01

    These results suggest that cells exposed to X-irradiation may respond differently to subsequent cisplatin (CDDP) treatment. Initial studies of possible mechanisms responsible for these differential sensitivities indicate that they may differ according to whether resistance or hypersensitivity is expressed. (author)

  12. Effect of cetuximab and fractionated irradiation on tumour micro-environment.

    NARCIS (Netherlands)

    Santiago, A.; Eicheler, W.; Bussink, J.; Rijken, P.F.J.W.; Yaromina, A.; Beuthien-Baumann, B.; Kogel, A.J. van der; Baumann, M.; Krause, M.

    2010-01-01

    BACKGROUND AND PURPOSE: Previous experiments have shown that application of the anti-EGFR monoclonal antibody C225 (cetuximab) improves local tumour control after irradiation in FaDu human squamous cell carcinoma (hSCC) due to the combined effect of decreased repopulation and improved reoxygenation.

  13. Measurement of absorbed doses near metal and dental material interfaces irradiated by x- and gamma-ray therapy beams

    International Nuclear Information System (INIS)

    Farahani, M.; Eichmiller, F.C.; McLaughlin, W.L.

    1990-01-01

    Soft-tissue damage adjacent to dental restorations is a deleterious side effect of radiation therapy associated with low-energy electron scatter from dental materials of high electron density. This study was designed to investigate the enhancement of dose to soft tissue (or water) close to high electron-density materials and to measure the detailed lateral and depth-dose profiles in soft-tissue-simulating polymer adjacent to planar interfaces of several higher atomic-number materials: 18-carat gold dental casting alloy; Ag-Hg dental amalgam alloy; Ni-Cr dental casting alloy; and natural human tooth structure. Results indicate that the dose-enhancement in 'tissue' is as great as a factor of 2 on the backscatter side adjacent to gold and a factor of 1.2 adjacent to tooth tissue, but is insignificant on the forward-scatter side because of the predominant effect of attenuation by the high-density, high atomic-number absorbing material. (author)

  14. Vertebral compression fractures after spine irradiation using conventional fractionation in patients with metastatic colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ree, Woo Joong; Kim, Kyung Hwan; Chang, Jee Suk; Kim, Hyun Ju; Choi, Seo Hee; Koom, Woong Sub [Dept.of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul (Korea, Republic of)

    2014-12-15

    To evaluate the risk of vertebral compression fracture (VCF) after conventional radiotherapy (RT) for colorectal cancer (CRC) with spine metastasis and to identify risk factors for VCF in metastatic and non-metastatic irradiated spines. We retrospectively reviewed 68 spinal segments in 16 patients who received conventional RT between 2009 and 2012. Fracture was defined as a newly developed VCF or progression of an existing fracture. The target volume included all metastatic spinal segments and one additional non-metastatic vertebra adjacent to the tumor-involved spines. The median follow-up was 7.8 months. Among all 68 spinal segments, there were six fracture events (8.8%) including three new VCFs and three fracture progressions. Observed VCF rates in vertebral segments with prior irradiation or pre-existing compression fracture were 30.0% and 75.0% respectively, compared with 5.2% and 4.7% for segments without prior irradiation or pre-existing compression fracture, respectively (both p < 0.05). The 1-year fracture-free probability was 87.8% (95% CI, 78.2-97.4). On multivariate analysis, prior irradiation (HR, 7.30; 95% CI, 1.31-40.86) and pre-existing compression fracture (HR, 18.45; 95% CI, 3.42-99.52) were independent risk factors for VCF. The incidence of VCF following conventional RT to the spine is not particularly high, regardless of metastatic tumor involvement. Spines that received irradiation and/or have pre-existing compression fracture before RT have an increased risk of VCF and require close observation.

  15. Fractionated total body irradiation and autologous bone marrow transplantation in dogs: Hemopoietic recovery after various marrow cell doses

    International Nuclear Information System (INIS)

    Bodenburger, U.; Kolb, H.J.; Thierfelder, S.; Netzel, B.; Schaeffer, E.; Kolb, H.

    1980-01-01

    Hemopoietic recovery was studied in dogs given 2400 R fractionated total body irradiation within one week and graded doses of cryopreserved autologous bone marrow. Complete hemopoietic recovery including histology was observed after this dose and sufficient doses of marrow cells. Doses of more than 5.5 x 10 7 mononuclear marrow cells/kg body weight were sufficient for complete recovery in all dogs, 1.5 to 5.5 x 10 7 cells/kg were effective in some of the dogs and less than 1.5 x 10 7 cells/kg were insufficient for complete recovery. Similarly, more than 30000 CFUsub(c)/kg body weight were required for hemopoietic recovery. The optimal marrow cell dose which has been defined as the minimal dose required for the earliest possible recovery of leukocyte and platelet counts was 7-8 x 10 7 mononuclear marrow cells/kg body weight. It has been concluded that fractionated total body irradiation with 2400 R dose not require greater doses of marrow cells for hemopoietic reconstitution than lower single doses and that the hemopoietic microenvironment is not persistently disturbed after this dose. (author)

  16. A pilot study to evaluate the cost-effectiveness of ondansetron and granisetron in fractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, S.J.; Cassoni, A.M. [Middlesex Hospital, London (United Kingdom)

    1996-11-01

    The duration of the antiemetic effect of granisetron was examined in a pilot study of patients (n = 26) undergoing a standard emetogenic stimulus in the form of total body irradiation fractionated over 3-4 days, in a randomized comparison with twice-daily ondansetron. A single intravenous dose of granisetron at the onset of therapy was effective over the entire follow-up period in 50% (6/12) of patients, compared with 77% (10/13) prescribed twice-daily oral ondansetron for 3 or 4 days. The response rate within the first 24 hours from the start of irradiation was 67% (8/12) for granisetron and 77% (10/13) for ondansetron. Granisetron and ondansetron was therefore of similar efficacy within the first 24-hour period, but granisetron was less efficaceous more than 24 hours after the onset of therapy. Patients who required a second dose of granisetron did so at intervals of 12, 42, 47 and 48 hours following the first fraction of radiotherapy. The cost per patient in this study was 48 for granisetron and {sub 1}54 for ondanestron, but the dose scheduling we used cannot be recommended in view of the lower effectiveness of granisetron. (author).

  17. A pilot study to evaluate the cost-effectiveness of ondansetron and granisetron in fractionated total body irradiation

    International Nuclear Information System (INIS)

    Gibbs, S.J.; Cassoni, A.M.

    1996-01-01

    The duration of the antiemetic effect of granisetron was examined in a pilot study of patients (n = 26) undergoing a standard emetogenic stimulus in the form of total body irradiation fractionated over 3-4 days, in a randomized comparison with twice-daily ondansetron. A single intravenous dose of granisetron at the onset of therapy was effective over the entire follow-up period in 50% (6/12) of patients, compared with 77% (10/13) prescribed twice-daily oral ondansetron for 3 or 4 days. The response rate within the first 24 hours from the start of irradiation was 67% (8/12) for granisetron and 77% (10/13) for ondansetron. Granisetron and ondansetron was therefore of similar efficacy within the first 24-hour period, but granisetron was less efficaceous more than 24 hours after the onset of therapy. Patients who required a second dose of granisetron did so at intervals of 12, 42, 47 and 48 hours following the first fraction of radiotherapy. The cost per patient in this study was 48 for granisetron and 1 54 for ondanestron, but the dose scheduling we used cannot be recommended in view of the lower effectiveness of granisetron. (author)

  18. Scanning electron microscopy and recording of the physiological activity of tracheal ciliated cells treated by fractionated irradiation

    International Nuclear Information System (INIS)

    Albertsson, M.; Hakansson, C.H.; Mecklenburg, C. von

    1983-01-01

    The ciliated epithelium of the rabbit's trachea was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy. The beat frequency of the cilia was recorded and specimens were taken for SEM-, TEM- and LM-investigations. Examination was made 1-10 days after each fractionation schedule. An increased ciliary beat frequency was recorded at 2 Gy and 4 Gy. With increasing dose, there was an inverted relationship to the frequency. Light-microscopy showed edema and an increased amount of goblet cells in relation to the increasing dose. With SEM an increased number of ciliary blebs could be seen. These could be classified according to size and number, and showed a positive correlation to the dose. TEM-investigations showed signs of increased intracellular activity at higher doses in the form of multilobulated nuclei and an increasing number of nuclear pores. At lower doses, an increased amount of mitochondria appeared in the apical part of the cell. It is at present difficult to evaluate any correlation between the physiological activity and the morphology. More biological data are needed to explain the early irradiation effects

  19. Exploiting the MODIS albedos with the Two-stream Inversion Package (JRC-TIP): 2. Fractions of transmitted and absorbed fluxes in the vegetation and soil layers

    Science.gov (United States)

    Pinty, B.; Clerici, M.; Andredakis, I.; Kaminski, T.; Taberner, M.; Verstraete, M. M.; Gobron, N.; Plummer, S.; Widlowski, J.-L.

    2011-05-01

    The two-stream model parameters and associated uncertainties retrieved by inversion against MODIS broadband visible and near-infrared white sky surface albedos were discussed in a companion paper. The present paper concentrates on the partitioning of the solar radiation fluxes delivered by the Joint Research Centre Two-stream Inversion Package (JRC-TIP). The estimation of the various flux fractions related to the vegetation and the background layers separately capitalizes on the probability density functions of the model parameters discussed in the companion paper. The propagation of uncertainties from the observations to the model parameters is achieved via the Hessian of the cost function and yields a covariance matrix of posterior parameter uncertainties. This matrix is propagated to the radiation fluxes via the model's Jacobian matrix of first derivatives. Results exhibit a rather good spatiotemporal consistency given that the prior values on the model parameters are not specified as a function of land cover type and/or vegetation phenological states. A specific investigation based on a scenario imposing stringent conditions of leaf absorbing and scattering properties highlights the impact of such constraints that are, as a matter of fact, currently adopted in vegetation index approaches. Special attention is also given to snow-covered and snow-contaminated areas since these regions encompass significant reflectance changes that strongly affect land surface processes. A definite asset of the JRC-TIP lies in its capability to control and ultimately relax a number of assumptions that are often implicit in traditional approaches. These features greatly help us understand the discrepancies between the different data sets of land surface properties and fluxes that are currently available. Through a series of selected examples, the inverse procedure implemented in the JRC-TIP is shown to be robust, reliable, and compliant with large-scale processing requirements

  20. Fractionated stereotactic irradiation by Cyberknife of choroid melanomas: repositioning validation, closed eyelids

    International Nuclear Information System (INIS)

    Horn, S.; Rezvoy, N.; Lacornerie, T.; Mirabel, X.; Labalette, P.; Lartigau, E.

    2009-01-01

    The fractionated stereotactic radiotherapy by Cyberknife is an option in the treatment of eyes tumors. The advantages of the Cyberknife in the choroid melanomas are in its infra-millimetric precision, to the automated repositioning on the skull bones and to the conformity brought by the stereotaxy. The objective of this study was to validate the quality of repositioning and the immobility of the eyes with closed eyelids. Conclusion: the reproducibility of the eye positioning with closed eyelids seems enough to consider the conservative treatment of choroid melanomas by fractionated stereotactic radiotherapy by Cyberknife without implementation of fiducials nor retrobulbar anaesthesia. (N.C.)

  1. Density crosslink study of gamma irradiated LDPE predicted by gel-fraction, swelling and glass transition temperature characterization

    International Nuclear Information System (INIS)

    Cardoso, Elisabeth C.L.; Scagliusi, Sandra R.; Moraes, Guilherme F.; Ono, Lilian S.; Parra, D.F.; Lugao, Ademar B.

    2011-01-01

    Experimental results showed that the crosslink density of polymeric stocks may be predicted from values of gel content based on the reactive portion of the stocks, that is, exclusive of plasticizers and fillers. Where entanglements may be neglected, the crosslink density is directly proportional to functions of the gel and sol contents. In order to predict the behavior of carbon-chain polymers exposed to ionizing radiation, an empirical rule can be used. According to this rule, polymers containing a hydrogen atom at each carbon atom predominantly undergo crosslinking. During irradiation, chain scission occurs simultaneously and competitively with crosslinking, the end result being determined by the ratio of the yields of the two reactions. The ratio of crosslinking to scission depends basically on factors including total irradiation dose, dose rate and the presence of oxygen. The glass transition temperature (Tg), temperature below which the polymer segments do not have sufficient energy to move past one another, marks the onset of segmental mobility for a polymer. Properties such as melt index, melt strength, crystallinity, glass transition, gel fraction, swelling ratio and elasticity modulus were assessed in LDPE (2.6 g.10 min -1 melt index) gamma irradiated within a 10, 15, 20 and 30 kGy and results obtained were further discussed prior conclusion. (author)

  2. The influence of single and fractionated dose external beam irradiation on injury-induced arterial smooth muscle cell proliferation

    International Nuclear Information System (INIS)

    Schaefer, U.; Micke, O.; Dorszewski, A.; Breithardt, G.; Willich, N.

    1997-01-01

    Purpose/Objective: Restenosis after catheter-based revascularization has been demonstrated to be primarily caused by smooth muscle cell proliferation. This study examined the effects of external beam irradiation on neointimal proliferation after external injury to the central artery of the rabbit ear. Materials and Methods: 40 male New Zealand White rabbits were used in this study. Crush lesions were performed on each ear under general anesthesia and bilateral auricular nerve blockade. A single dose of 12 Gy (n=10), 16 Gy (n=10), or 20 Gy (n=10) and a fractionated dose of 4 x 5 Gy (n=10) gamma radiation was delivered to the left or right central artery of the ear 24 hours after injury; the contralateral central artery served as control. All rabbits were sacrificed after twenty-one days and the central arteries of the ear were fixed for morphometric measurements. Results: Mean (± SD) neointimal area was 0.062 ± 0.005 mm 2 (12 Gy), 0.022 ± 0,005 mm 2 (16 Gy), 0,028 ± 0,006 mm 2 and 0.038 mm 2 ± 0,02 mm 2 (4 x 5 Gy) in irradiated arteries compared with 0,081 ± 0,009 mm 2 in the control group. Mean (±SD) luminal area was 0.049 ± 0.004 mm 2 (12 Gy), 0.059 ± 0.002 mm 2 (16 Gy), 0.072 ± 0,006 mm 2 (20 Gy) and 0.048 mm 2 ± 0,018 mm 2 (4 x 5 Gy) in irradiated arteries compared with 0,043 ± 0,008 mm 2 in the control group. The difference in neointimal and luminal area between control and irradiated arteries was significant (p<0.05) only for the 16 and 20 Gy group compared to control. Conclusion: We conclude that in this model, external beam X-ray irradiation was successful in reducing neointimal proliferation after injury of the central artery of the rabbit ear. The optimal dose seems to be a single dose of 16 Gy - 20 Gy. Only a less prominent effect was noted for a fractionated dose of 4 x 5 Gy. Whether this approach can be used successfully to inhibit restenosis in the clinical setting requires further investigation

  3. Numerical absorbed dose distributions inside principal organs of a mathematical anthropomorphic phantom irradiated by monoenergetic photon fields

    International Nuclear Information System (INIS)

    Furstoss, C.; Menard, S.

    2005-01-01

    Full text: Personnel can be exposed to photon or mixed (neutrons and photons) radiations at workplaces for various activities (nuclear fuel cycle, medical sector, research... ). The passive and active personal dosimeters worn on the trunk evaluate the personal dose equivalent Hp(10), defined by ICRP 601 to be an estimator of the effective dose E. However, the angular and energy distributions of the radiations encountered could generate an over or under-estimation of the protection quantity E because of the response of the dosimeters or/and because of the definition of Hp(10) itself. The Institute of Radiological Protection and Nuclear Safety (IRSN) is evaluating the possibility of the measurement of the effective dose E using an instrumented anthropomorphic phantom at workplaces. Such an instrument would allow the control of the suitability of the radiological protection instrumentation used at workplaces for radiation fields which can appreciably differ from the reference ISO radiation fields used to calibrate dosimeters. The objectives of this study are to determine key positions for the future detectors inside and on the phantom, as well as their needed technical characteristics. The simulations of the organ absorbed dose distributions performed using the Monte Carlo code MCNPX2 and the MIRD phantom3 model will allow the determination of the detector locations. This paper will present the first numerical results obtained for monoenergetic parallel photon fields. The effective doses E calculated in an energy range from 15 keV to 10 MeV will be presented and compared with the results of M. Zankl et al., published in the GSF report Bericht 8/974. (author)

  4. Comparison of Radiation-Induced Bystander Effect in QU-DB Cells after Acute and Fractionated Irradiation: An In Vitro Study.

    Science.gov (United States)

    Soleymanifard, Shokouhozaman; Bahreyni Toossi, Mohammad Taghi; Kamran Samani, Roghayeh; Mohebbi, Shokoufeh

    2016-01-01

    Radiation effects induced in non-irradiated cells are termed radiation-induced bystander effects (RIBE). The present study intends to examine the RIBE response of QU-DB bystander cells to first, second and third radiation fractions and compare their cumulative outcome with an equal, single acute dose. This experimental study irradiated three groups of target cells for one, two and three times with(60)Co gamma rays. One hour after irradiation, we transferred their culture media to non-irradiated (bystander) cells. We used the cytokinesis block micronucleus assay to evaluate RIBE response in the bystander cells. The numbers of micronuclei generated in bystander cells were determined. RIBE response to single acute doses increased up to 4 Gy, then decreased, and finally at the 8 Gy dose disappeared. The second and third fractions induced RIBE in bystander cells, except when RIBE reached to the maximum level at the first fraction. We split the 4 Gy acute dose into two fractions, which decreased the RIBE response. However, fractionation of 6 Gy (into two fractions of 3 Gy or three fractions of 2 Gy) had no effect on RIBE response. When we split the 8 Gy acute dose into two fractions we observed RIBE, which had disappeared following the single 8 Gy dose. The impact of dose fractionation on RIBE induced in QU-DB cells de- pended on the RIBE dose-response relationship. Where RIBE increased proportion- ally with the dose, fractionation reduced the RIBE response. In contrast, at high dos- es where RIBE decreased proportionally with the dose, fractionation either did not change RIBE (at 6 Gy) or increased it (at 8 Gy).

  5. Alterations in growth phenotype and radiosensitivity after fractionated irradiation of breast carcinoma cells from a single patient

    International Nuclear Information System (INIS)

    Wazer, D.E.; Joyce, M.; Jung, L.; Band, V.

    1993-01-01

    The purpose was to investigate growth regulation and radiosensitivity in surviving clonogens after fractionated irradiation. Four breast carcinoma cell lines isolated from the primary tumor (21NT, 21PT) and metastases (21MT-1, 21MT-2) of a single patient were exposed to cumulative radiation doses of 30 Gy yielding cell lines designated -IR with respect to their parent. The irradiated lines were then compared to their parent for serum- and growth factor-requirements under defined media conditions, ability to proliferate in soft agar, concentration of TGF-alpha in conditioned medium, and radiosensitivity. The irradiated lines showed no change in proliferative doubling times under serum- and growth factor-supplemented media conditions. A single line, 21MT-1-IR, acquired a limited ability to proliferate in serum- and growth factor-deplete medium with a day 2-4 doubling time of 44.5 hr. Three lines, 21MT-1-IR, 21MT-2-IR, and 21NT-IR, formed colonies in soft agar in contrast to none of the unirradiated parent lines. There were significant 6-8 fold increases in conditioned media TGF-alpha concentrations for 21MT-2-IR and 21NT-IR cells. The 21MT-1-IR and 21NT-IR cells were significantly less radiosensitive than their respective parent lines. This decrease in radiosensitivity appeared to be at least partially mediated by a released factor as the radiosensitivity of 21MT-1 cells was significantly decreased by pre-incubation with conditioned medium from 21MT-1-IR cells. Radiation-induced changes in growth phenotype vary with respect to clonal origin of the cell line and may influence the radiosensitivity of surviving clonogens after fractionated treatment. 18 refs., 4 figs., 3 tabs

  6. Shock absorber

    International Nuclear Information System (INIS)

    Housman, J.J.

    1978-01-01

    A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

  7. International Workshop on “Generalized Concavity, Fractional Programming and Economic Applications”

    CERN Document Server

    Castagnoli, Erio; Martein, Laura; Mazzoleni, Piera; Schaible, Siegfried

    1990-01-01

    Generalizations of convex functions have been used in a variety of fields such as economics. business administration. engineering. statistics and applied sciences.· In 1949 de Finetti introduced one of the fundamental of generalized convex functions characterized by convex level sets which are now known as quasiconvex functions. Since then numerous types of generalized convex functions have been defined in accordance with the need of particular applications.· In each case such functions preserve soine of the valuable properties of a convex function. In addition to generalized convex functions this volume deals with fractional programs. These are constrained optimization problems which in the objective function involve one or several ratios. Such functions are often generalized convex. Fractional programs arise in management science. economics and numerical mathematics for example. In order to promote the circulation and development of research in this field. an international workshop on "Generalized Concavi...

  8. PAI-1 levels predict response to fractionated irradiation in 10 human squamous cell carcinoma lines of the head and neck

    International Nuclear Information System (INIS)

    Bayer, Christine; Schilling, Daniela; Hoetzel, Joerg; Egermann, Hannes Peter; Zips, Daniel; Yaromina, Ala; Geurts-Moespot, Anneke; Sprague, Lisa Deborah; Sweep, Fred; Baumann, Michael; Molls, Michael; Adam, Markus

    2008-01-01

    Background and purpose: To investigate the relationships between hypoxia, VEGF and components of the plasminogen activation system (PAS) and to determine their influence on local tumour control after fractionated radiotherapy. Material and methods: Ten cell lines derived from human squamous cell carcinomas of the head and neck (SCCHN) were investigated in vitro and used to generate xenograft tumours. The pimonidazole hypoxic fraction in the total tumour area (pHF tot ) was used to measure hypoxia in pre-treatment tumours and the local tumour control (TCD 50 ) was used as the functional endpoint in vivo. For in vitro experiments, cells were cultured for 24 h under either normoxic or mild hypoxic (∼0.66% O 2 ) conditions. VEGF, PAI-1 and uPA antigen levels were determined by ELISA and uPA activity by an activity assay kit. Results: Of all the factors investigated, only PAI-1 expression correlated with TCD 50 (r = 0.80, p 0.010) and was significantly higher (p = 0.001) in more hypoxic than in less hypoxic tumours. Accordingly, PAI-1 secretion was significantly induced (2.4x) by in vitro hypoxia. Conclusions: These results suggest that pre-treatment PAI-1 levels are higher in more hypoxic tumours and can predict the response to fractionated irradiation in SCCHN

  9. Investigation of high flux test module for the international fusion materials irradiation facilities (IFMIF)

    International Nuclear Information System (INIS)

    Miyashita, Makoto; Sugimoto, Masayoshi; Yutani, Toshiaki

    2007-03-01

    This report describes investigation on structure of a high neutron flux test module (HFTM) for the International Fusion Materials Irradiation Facilities (IFMIF). The HFTM is aimed for neutron irradiation of a specimen in a high neutron flux domain of the test cell for irradiation ground of IFMIF. We investigated the overall structure of the HFTM that was able to include specimens in a rig and thermocouple arrangement, an interface of control signal and support structure. Moreover, pressure and the amount of the bend in the module vessel (a rectangular section pressure vessel) were calculated. The module vessel did a rectangular section from limitation of a high neutron flux domain. Also, we investigated damage of thermocouples under neutron irradiation, which was a temperature sensor of irradiation materials temperature control demanded high precision. Based on these results, drawings on the HTFM structure. (author)

  10. Influence of electron irradiation on internal friction and structure evolution of polymer composites

    International Nuclear Information System (INIS)

    Ismailova, G.A.

    2007-01-01

    Full text: Important qualitative information on structural evolution and radiation alterations in polymer materials under the action of ionizing radiation can be obtained from the analysis of the temperature dependences of internal friction. Changing of internal friction parameters of relax maxima during irradiation is qualitative degree parameter of radiation scission-cross linking of the polymer molecules. In this work, the general phenomenological approach is realized by introduction of the effective 'observed' parameters into the simple kinetic equations. The applicability of such approach is justified by the fact that kinetics of both internal friction and scission-cross linking processes can be characterized by the same effective parameters. Temperature dependences of internal friction are experimentally studied in epoxy irradiated by 2.5 MeV pulse electron beam to different doses (D=3 MGy, 6 MGy and 9 MGy). Time dependences of internal friction characteristics associated with radiation-induced processes of polymer scission and cross-linking are analyzed and discussed. Experimental data on kinetics of structural transformations in epoxy are interpreted on the base of analytical solutions of differential equations for free radical accumulation during and after irradiation subject to the arbitrary effective order of radical recombination. It is shown that in the range of doses and dose rates under study radiation-induced scission predominates during polymer irradiation but in a certain period of time after irradiation scission changes to cross-linking. Characteristics of the kinetic curves obtained essentially depend on the dose

  11. Evaluation of the efficacy of palliative irradiation with high fractionated doses and planned intervals of patients with advanced cancer of the oral cavity and pharynx

    International Nuclear Information System (INIS)

    Skolyszewski, J.; Reinfuss, M.

    1988-01-01

    200 patients, previously not treated, with advanced highly differentiated cancer of the oral cavity and pharynx have been palliatively irradiated in the Oncology Center in Cracow in the years 1976-1985. Megavoltage irradiation with fractionated doses 4-5 Gy up to the dose of 20 Gy to the tumor with 4-5 fractions during 4-7 days has been applied. 64 patients received 20 Gy as simple dose, in 65 cases such dose has been repeated after month. 71 patients have been irradiated for the third time with similar dose after another 1 month interval. Partial regression of 25-50% of the tumor volume has been obtained after the first series of irradiation in 19% of patients and more than 50% in 28% of patients, complete regression in 4% of patients. 15,5% of the total number of patients survived 1 year since the initiation of the irradiation, 5% without symptoms of the neoplasm. Worse prognosis is connected with major advancement of the tumor (T 4 , N 2 ), poor general condition, cachexia and alcohol addition. Absence of improvement after the first series of irradiations indicates the non-effectiveness of the treatment. Palliative treatment by irradiation with high fractionated doses and planned interval is a safe and efficacious method. 1 fig., 6 tabs., 14 refs. (author)

  12. Acute hematological tolerance to multiple fraction, whole body, low dose irradiation in an experimental murine system

    International Nuclear Information System (INIS)

    Melamed, J.S.; Chen, M.G.; Brown, J.W.; Katagiri, C.A.

    1980-01-01

    Using a dose fractionation scheme patterned after the current regimen for treatment of disseminated non-Hodgkin lymphoma, the authors studied the effects of irradation on progenitor and effector cells for hematopoiesis in five-month-old BC3F 1 mice. Fractions of 20 or 50 rad (0.2 or 0.5 Gy) total body irradation were given twice weekly to a final total dose of 200 or 500 rad (2 or 5 Gy), respectively. Weekly assays revealed a marked, sustained depression of stem cell activity, measured as numbers of spleen colony-forming units (CFU-S) and in vitro colony-forming cells (CFU-C), without corresponding depression of effector cells (red and white cells, and platelets). The lack of correlation between numbers of stem cells and peripheral elements is relevant to clinical assessment of marrow reserve

  13. Mitigating IASCC of Reactor Core Internals by Post-Irradiation Annealing

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-06-02

    This final report summarizes research performed during the period between September 2012 and December 2016, with the objective of establishing the effectiveness of post-irradiation annealing (PIA) as an advanced mitigation strategy for irradiation-assisted stress corrosion cracking (IASCC). This was completed by using irradiated 304SS control blade material to conduct crack initiation and crack growth rate (CGR) experiments in simulated BWR environment. The mechanism by which PIA affects IASCC susceptibility will also be verified. The success of this project will provide a foundation for the use of PIA as a mitigation strategy for core internal components in commercial reactors.

  14. Mitigating IASCC of Reactor Core Internals by Post-Irradiation Annealing

    International Nuclear Information System (INIS)

    Was, Gary

    2017-01-01

    This final report summarizes research performed during the period between September 2012 and December 2016, with the objective of establishing the effectiveness of post-irradiation annealing (PIA) as an advanced mitigation strategy for irradiation-assisted stress corrosion cracking (IASCC). This was completed by using irradiated 304SS control blade material to conduct crack initiation and crack growth rate (CGR) experiments in simulated BWR environment. The mechanism by which PIA affects IASCC susceptibility will also be verified. The success of this project will provide a foundation for the use of PIA as a mitigation strategy for core internal components in commercial reactors.

  15. 15 years of existence of the International Consultative Group on Food Irradiation (ICGFI)

    International Nuclear Information System (INIS)

    Ehlermann, D.A.E.

    1999-01-01

    The ICGFI essentially contributed to international dissemination of unbiased information about the advantages and risks of food irradiation. The body has issued ICGFI publications containing codes of good practice for a variety of purposes, as eg. for operation of irradiation facilities for the treatment of food (GIP), or guidelines for due handling of irradiated food (GMP). Training courses have been offered to scientists, especially from developing countries, as well as for inspectors of national supervisory authorities. The activities of the advisory group as well as the conditions governing future activities are discussed. (orig./CB) [de

  16. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    Directory of Open Access Journals (Sweden)

    Shaikh Arif Y

    2012-02-01

    Full Text Available Abstract Background There are limited data on accelerated partial breast irradiation (APBI using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC are suitable for APBI. Methods The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC, ILC, or Tis (DCIS treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF was pathologically confirmed as a local failure (LF or an elsewhere failure (EF. Results Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9% including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. Conclusions External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not

  17. Effect of gamma irradiation on the activity of alanine and aspartate transaminases in subcellular fractions of the brain and heart in white rats

    Energy Technology Data Exchange (ETDEWEB)

    Plenin, A E

    1973-01-01

    In experiments on rats, the activity of alanine (I) and aspartate transaminases (II) was studied in homogenates and subcellular fractions of the brain and myocardium under normal conditions and for 30 days after ..gamma.. irradiation at 40 rads. The activity of II in brain homogenates increased 1 hour after irradiation but decreased by 20 percent on day 3; it decreased again on days 7 and 15. The activity of brain I increased after 1 hour and 3 days but then returned to normal. The activity of I in heart homogenates increased in all the periods after irradiation. The subcellular fractions exhibited phase changes in the activity of the enzymes. These changes were different in nature from those observed after X and ..gamma.. irradiation at the same dose.

  18. The severity of late rectal and recto-sigmoid complications related to fraction size in irradiation treatment of carcinoma cervix stage III B

    International Nuclear Information System (INIS)

    Deore, S.M.; Shrivastava, S.K.; Viswanathan, P.S.; Dinshaw, K.A.; Tata Memorial Hospital, Bombay

    1991-01-01

    A retrospective analysis of late rectal and recto-sigmoid complications was carried out of the 203 patients with stage III B carcinoma of uterine cervix, treated using radiation therapy alone during January 1979 to December 1983. The patients were treated with a combination of external irradiation and single intracavitary insertion. External irradiation was randomised to one of the four different fractionation regimes having dose per fraction of 2 Gy, 3 Gy, 4 Gy and 5.4 Gy, delivering with five fractions/week, three fractions/week, two fractions/week and one fraction/week, respectively. The total doses in four different regimens were adjusted using the TDF model. There were 39 cases of late radiation induced rectal and recto-sigmoid complications. The complication rate was correlated with the dose per fraction and TDFs delivered in each regimen. The complication rate of 8.2% for 2 Gy per fraction was increased to 33.33% for 5.4 Gy per fraction. It was found that there is strong correlation (P [de

  19. A method for evaluation of proton plan robustness towards inter-fractional motion applied to pelvic lymph node irradiation

    DEFF Research Database (Denmark)

    Andersen, Andreas G; Casares-Magaz, Oscar; Muren, Ludvig P

    2015-01-01

    of the pelvic lymph nodes (LNs) from different beam angles. Patient- versus population-specific patterns in dose deterioration were explored. MATERIAL AND METHODS: Patient data sets consisting of a planning computed tomography (pCT) as well as multiple repeat CT (rCT) scans for three patients were used......BACKGROUND: The benefit of proton therapy may be jeopardized by dose deterioration caused by water equivalent path length (WEPL) variations. In this study we introduced a method to evaluate robustness of proton therapy with respect to inter-fractional motion and applied it to irradiation...... in deterioration patterns were found for the investigated patients, with beam angles delivering less dose to rectum, bladder and overall normal tissue identified around 40° and around 150°-160° for the left LNs, and corresponding angles for the right LNs. These angles were also associated with low values of WEPL...

  20. Nucleic acid metabolism in hemopoietic tissues of polycythemic rats during long-term fractionated irradiation

    International Nuclear Information System (INIS)

    Mushkacheva, G.S.; Murzina, L.D.

    1980-01-01

    A study was made of the effect of long-term fractionated exposure with a daily dose of 50 R on the nucleic acid metabolism in hemopoietic tissues (bone marrow and spleen) of rats with erythropoiesis selectively inhibited by posttransfusion polycythemia. The comparison of present and previously obtained results enables us to conclude that the pathways of changes in the nucleic acid metabolism, which is responsible for hemopoiesis compensation during long-term exposure, are, in the main, similar for both white and red compartments of hemopoiesis

  1. Expression of P-glycoprotein and multidrug resistance associated protein in Ehrlich ascites tumor cells after fractionated irradiation

    International Nuclear Information System (INIS)

    Nielsen, Dorte; Maare, Christian; Eriksen, Jens; Litman, Thomas; Skovsgaard, Torben

    2001-01-01

    Purpose: To characterize irradiated murine tumor cells with respect to drug resistance, drug kinetics, and ATPase activity, and to evaluate the possible role of P-glycoprotein (PGP) and murine multidrug resistance associated protein (Mrp1) in the drug-resistant phenotype of these cells. Methods and Materials: Sensitive Ehrlich ascites tumor cells (EHR2) were in vitro exposed to fractionated irradiation (60 Gy). Western blot analysis was performed for determination of PGP and Mrp1, reverse transcriptase-polymerase chain reaction (RT-PCR) for determination of mdr1a + b mRNA, and semiquantitative RT-PCR for Mrp1 mRNA. The clonogenic assay was applied to investigate sensitivity, whereas the steady-state drug accumulation of daunorubicin (DNR), 3 H-vincristine (VCR), and 3 H-etoposide (VP16) was measured by spectrofluorometry and scintillation counting, respectively. For determining of ATPase activity, the release of inorganic phosphate from ATP was quantified using a colorimetric method. Results: Compared with EHR2, the irradiated cell line EHR2/irr showed increased expression of PGP (threefold), Mrp1 (eightfold), and Mrp1 mRNA (sixfold), and a slight reduction of mdr1b mRNA, whereas mdr1a was present in EHR2 but could not be detected in EHR2/irr. EHR2/irr developed sixfold resistance to VP16, twofold resistance to vincristine, but remained sensitive to DNR. Addition of the PGP inhibitor, verapamil (VER) or depletion of glutathione by buthionine sulfoximine (BSO) partly reversed the resistance in EHR2/irr. In EHR2/irr, the steady-state accumulation of 3 H-VCR and 3 H-VP16 was significantly decreased as compared with EHR2, whereas the accumulation of DNR was unchanged. The ATPase activity of plasma membrane vesicles prepared from EHR2/irr cells was similar to that of wild-type EHR2 cells. The ATPase activity was neither stimulated by vinblastine nor VER. Conclusion: Irradiation induced a multidrug-resistant phenotype in sensitive tumor cells. This phenotype was

  2. Influence of clinical and tumoral factors on the inter-fractions bones displacements during the treatment of gastric or esophagus cancers by external irradiation

    International Nuclear Information System (INIS)

    Quivrin, M.; Peignaux, K.; Truc, G.; Blanchard, N.; Ligey-Bartolomeu, A.; Maingon, P.; Crehange, G.; Liegard, M.; Bonnetain, F.; Petitfils, A.

    2009-01-01

    Purpose: to evaluate the influence of clinical and tumoral characteristics on the inter fractions bones displacements during the irradiation of eso gastric cancers. Conclusion: the local control of irradiated esophagus and gastric cancers stay not satisfying and could be improved by the individual adjustment of peritumoral margins in function of clinical and tumoral characteristics as age, sex, average weight at the beginning of the treatment, the index of the initial average body mass. (N.C.)

  3. Changes of the lactate dehydrogenase in the tissue fraction with Walker carcinoma under irradiation

    International Nuclear Information System (INIS)

    Schultheis, W.

    1972-01-01

    The behaviour of LDH, GOT and GPT of one and the same tissue with and without irradiation treatment as a means of cancer diagnosis is presented. Parallel to this, the corresponding blood values are determined, and an agar-gel isoenzyme separation of the LDH is carried out. In the 11 day-old Walker carcinoma of the rat, total tumour LDH as well as total serum LDH are increased. The X-radiation does not affect the result. The M 4 isoenzyme is mainly found in the tumour tissue, to whose benefit the tumour sera also change. In tissue processing, LDH, GOT and GPT behave corresponding to their occurence in the cell compartments. The enzymes, however, appear to differ in their solution behaviour. X-radiation leeds to an early removal of these enzymes in the sense of an 'enzyme release'. (BSC/LH) [de

  4. Correlation functions for the fractional generalized Langevin equation in the presence of internal and external noise

    International Nuclear Information System (INIS)

    Sandev, Trifce; Metzler, Ralf; Tomovski, Živorad

    2014-01-01

    We study generalized fractional Langevin equations in the presence of a harmonic potential. General expressions for the mean velocity and particle displacement, the mean squared displacement, position and velocity correlation functions, as well as normalized displacement correlation function are derived. We report exact results for the cases of internal and external friction, that is, when the driving noise is either internal and thus the fluctuation-dissipation relation is fulfilled or when the noise is external. The asymptotic behavior of the generalized stochastic oscillator is investigated, and the case of high viscous damping (overdamped limit) is considered. Additional behaviors of the normalized displacement correlation functions different from those for the regular damped harmonic oscillator are observed. In addition, the cases of a constant external force and the force free case are obtained. The validity of the generalized Einstein relation for this process is discussed. The considered fractional generalized Langevin equation may be used to model anomalous diffusive processes including single file-type diffusion

  5. Internal friction study of neutron-irradiation effects on an amorphous Cu40Ti60 alloy

    International Nuclear Information System (INIS)

    Dong, Y.; Wu, G.; Xiao, K.; Li, X.; He, Y.

    1988-01-01

    Effects of neutron irradiation on the structure of an amorphous Cu 40 Ti 60 alloy have been studied by internal friction measurements. After irradiation, the position of the first internal friction peak remains almost unchanged and the shoulder position shifts towards a higher temperature by about 5 K, which indicates that the Cu 40 Ti 60 glass becomes more stable. These results are finally discussed based on the concept of changes of chemical short-range ordering and geometrical short-range ordering due to radiation damage

  6. Degradation of austenitic stainless steel (SS) light water ractor (LWR) core internals due to neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Appajosula S., E-mail: Appajosula.Rao@nrc.gov

    2014-04-01

    Austenitic stainless steels (SSs) are extensively being used in the fabrication of light water reactor (LWR) core internal components. It is because these steels have relatively high ductility, fracture toughness and moderate strength. However, the LWR internal components exposure to neutron irradiation over an extended period of plant operation degrades the materials mechanical properties such as the fracture toughness. This paper summarizes some of the results of the existing open literature data on irradiation assisted stress corrosion cracking (IASCC) of 316 CW steels that have been published by the United States Nuclear Regulatory Commission (USNRC), industry, academia, and other research agencies.

  7. Characterization of the multiple drug resistance phenotype expressed by tumour cells following in vitro exposure to fractionated X-irradiation

    International Nuclear Information System (INIS)

    Hill, B.T.; McClean, S.; Hosking, L.; Shellard, S.; Dempke, W.; Whelan, R.

    1992-01-01

    The major clinical problem of the emergence of drug resistant tumor cell populations is recognized in patients previously treated with antitumor drugs and with radiotherapy. It is proposed that, although radiation-induced vascular fibrosis may limit drug delivery to the tumor, exposure to radiation may 'induce' or 'select for' drug resistance. This hypothesis was examined by establishing in vitro model systems to investigate the resistance phenotype of tumor cells following exposure to X-rays. Characteristically tumor cells surviving exposure to a series of fractions of X-irradiation are shown to have consistently expressed resistance to multiple drugs, including the Vinca alkaloids and the epipodophyllotoxins. Currently this research is aimed at determining whether distinctive resistance mechanisms operate depending on whether resistance results following drug or X-ray exposure. Initial results indicate that whilst some common mechanisms operate, drug resistant tumor cells identified following exposure to X-irradiation appear to exhibit a novel multidrug resistance phenotype. (author). 13 refs., 1 tab

  8. Radiosensitivity of Nicotiana protoplasts. Action on cell; cycle effects of low dose and fractionated irradiations; biological repair

    International Nuclear Information System (INIS)

    Magnien, E.

    1981-10-01

    Leaf protoplasts of Nicotiana plumbaginifolia and Nicotiana sylvestris demonstrate five main qualities: they can be maintained as haploid lines; they constitute starting populations with a remarkable cytological homogeneity; they show a transient initial lag-phase; they yield very high plating efficiencies and retain permanently a complete differentiation capacity; being derived of a cell wall, they appear well adapted for fusion experiments or enzymatic dosages. The resumption of mitotic activity was followed by cytophotometric measurements, labelling experiments, nuclear sizing and enzymatic assays. The action of 5 Gy gamma-ray irradiations delayed entrance in the S-phase, provoked an otherwise not verified dependency between transcription, translation and protein synthesis, increased nuclear volumes in the G2-phase, and slightly stimulated the activity of a repair enzyme. The plating efficiency was a sensitive end-point which allowed the evaluation of the biological effectiveness of low to medium radiation-doses after gamma-ray and fast neutron irradiations. The neutron dose-RBE relationship increased from 3 to 25 when the dose decreased from 5 Gy to 5 mGy. When fractionated into low single doses only, a neutron dose of 300 mGy markedly increased its biological effectiveness: this phenomenon could not be explained by cell progression, and necessitated additional hypotheses involving other mechanisms in the specific action of low radiation doses. Radiation-induced UDS was measured in presence of aphidicolin. A beta-like DNA-polymerase was shown to be definitely involved in nuclear repair synthesis [fr

  9. Hypofractionated Prostate Radiotherapy with or without Conventionally Fractionated Nodal Irradiation: Clinical Toxicity Observations and Retrospective Daily Dosimetry.

    Science.gov (United States)

    McDonald, Andrew M; Bishop, Justin M; Jacob, Rojymon; Dobelbower, Michael C; Kim, Robert Y; Yang, Eddy S; Smith, Heather; Wu, Xingen; Fiveash, John B

    2012-01-01

    Purpose. To evaluate toxicity associated with the addition of elective nodal irradiation (ENI) to a hypofractionated regimen for the treatment of prostate cancer. Methods and Materials. Fifty-seven patients received pelvic image-guided IMRT to 50.4 Gy in 28 fractions with a hypofractionated simultaneous boost to the prostate to 70 Gy. Thirty-one patients received prostate-only treatment to 70 Gy in 28 fractions. Results. Median followup was 41.1 months. Early grade ≥2 urinary toxicity rates were 49% (28 of 57) for patients receiving ENI and 58% (18 of 31) for those not (P = 0.61). Early grade ≥2 rectal toxicity rates were 40% (23 of 57) and 23% (7 of 31), respectively (P = 0.09). The addition of ENI resulted in a 21% actuarial rate of late grade ≥2 rectal toxicity at 4 years, compared to 0% for patients treated to the prostate only (P = 0.02). Retrospective daily dosimetry of patients experiencing late rectal toxicity revealed an average increase of 2.67% of the rectal volume receiving 70 Gy compared to the original plan. Conclusions. The addition of ENI resulted in an increased risk of late rectal toxicity. Grade ≥2 late rectal toxicity was associated with worse daily rectal dosimetry compared to the treatment plan.

  10. Long-term renal toxicity in children following fractionated total-body irradiation (TBI) before allogeneic stem cell transplantation (SCT)

    International Nuclear Information System (INIS)

    Gerstein, Johanna; Meyer, Andreas; Fruehauf, Joerg; Karstens, Johann H.; Bremer, Michael; Sykora, Karl-Walter

    2009-01-01

    Purpose: to retrospectively assess the incidence and time course of renal dysfunction in children (≤ 16 years) following total-body irradiation (TBI) before allogeneic stem cell transplantation (SCT). Patients and methods: between 1986 and 2003, 92 children (median age, 11 years; range, 3-16 years) underwent TBI before allogeneic SCT. 43 of them had a minimum follow-up of 12 months (median, 51 months; range, 12-186 months) and were included into this analysis. Conditioning regimen included chemotherapy and fractionated TBI with 12 Gy (n = 26) or 11.1 Gy (n = 17). In one patient, renal dose was limited to 10 Gy by customized renal shielding due to known nephropathy prior to SCt. Renal dysfunction was defined as an increase of serum creatinine > 1.25 times the upper limit of age-dependent normal. Results: twelve children (28%) experienced an episode of renal dysfunction after a median of 2 months (range, 1-10 months) following SCT. In all but one patient renal dysfunction was transient and resolved after a median of 8 months (range, 3-16 months). One single patient developed persistent renal dysfunction with onset at 10 months after SCT. None of these patients required dialysis. The actuarial 3-year freedom from persistent renal toxicity for children surviving > 12 months after SCt was 97.3%. Conclusion: the incidence of persistent renal dysfunction after fractionated TBI with total doses ≤ 12 Gy was very low in this analysis. (orig.)

  11. Neutronics analysis of International Fusion Material Irradiation Facility (IFMIF). Japanese contributions

    International Nuclear Information System (INIS)

    Oyama, Yukio; Noda, Kenji; Kosako, Kazuaki.

    1997-10-01

    In fusion reactor development for demonstration reactor, i.e., DEMO, materials tolerable for D-T neutron irradiation are absolutely required for both mechanical and safety point of views. For this requirement, several kinds of low activation materials were proposed. However, experimental data by actual D-T fusion neutron irradiation have not existed so far because of lack of fusion neutron irradiation facility, except fundamental radiation damage studies at very low neutron fluence. Therefore such a facility has been strongly requested. According to agreement of need for such a facility among the international parties, a conceptual design activity (CDA) of International Fusion Material Irradiation Facility (IFMIF) has been carried out under the frame work of the IEA-Implementing Agreement. In the activity, a neutronics analysis on irradiation field optimization in the IFMIF test cell was performed in three parties, Japan, US and EU. As the Japanese contribution, the present paper describes a neutron source term as well as incident deuteron beam angle optimization of two beam geometry, beam shape (foot print) optimization, and dpa, gas production and heating estimation inside various material loading Module, including a sensitivity analysis of source term uncertainty to the estimated irradiation parameters. (author)

  12. Early radiation changes of normal dog brain following internal and external brain irradiation: A preliminary report

    International Nuclear Information System (INIS)

    Chin, H.; Maruyama, Y.; Markesbery, W.; Goldstein, S.; Wang, P.; Tibbs, P.; Young, B.; Feola, J.; Beach, L.

    1984-01-01

    To examine radiation-induced changes in the normal brain, internal or external radiation was given to normal dog brain. Seven medium-sized dogs were used in this study. Two dogs were controls and an ice-pick (plastic implant applicator) was placed in the right frontal lobe for about 5 hours but no irradiation. Two dogs underwent Cs-137 brain implantation for 4 and 5 hours, respectively using an ice-pick technique. Two dogs were given internal neutron irradiation using the same technique of intracerebral ice-pick brachytherapy. One dog received an external photon irradiation using 6-Mev Linear Accelerator. Postmortem microscopic examination was made to study the early cerebral changes to irradiation in three dogs: one control with no irradiation; one received intracerebral Cesium implantation; and one external photon irradiation. Vascular change was the most prominent microscopic finding. There were hemorrhage, endothelial proliferation and fibrinoid changes of small vessel wall. Most of the changes were localized in the white matter and the cortex remained intact. Details (CT, NMR and histological studies) are discussed

  13. Evaluation of photo destruction of chromophores of heme and globin components in UV-irradiated human carboxyhemoglobin and its electrophoretic fractions

    International Nuclear Information System (INIS)

    Putintseva, O.V.; Artykhov, V.G.; Kalaeva, E.A.

    2000-01-01

    The contribution of hem and globin components of electrophoretic fractions of UV-irradiated human carboxyhemoglobin to photo destruction of the protein was studied. The changes observed are the result of summation of some processes unequal in intensity and direction that take place in microgeterogenous media of photo modified protein. Photo sensitivity of hemoproteid in electrophoretic fraction depends on apoprotein condition, whereas the hem photo resistance cannot be the evidence of the photo stability of the whole molecule [ru

  14. Acute and Short-Term Toxicities of Conventionally Fractionated Versus Hypofractionated Whole Breast Irradiation in a Prospective, Randomized Trial

    Science.gov (United States)

    Shaitelman, Simona F.; Schlembach, Pamela J.; Arzu, Isidora; Ballo, Matthew; Bloom, Elizabeth S.; Buchholz, Daniel; Chronowski, Gregory M.; Dvorak, Tomas; Grade, Emily; Hoffman, Karen E.; Kelly, Patrick; Ludwig, Michelle; Perkins, George H.; Reed, Valerie; Shah, Shalin; Stauder, Michael C.; Strom, Eric A.; Tereffe, Welela; Woodward, Wendy A.; Ensor, Joe; Baumann, Donald; Thompson, Alastair M.; Amaya, Diana; Davis, Tanisha; Guerra, William; Hamblin, Lois; Hortobagyi, Gabriel; Hunt, Kelly K.; Buchholz, Thomas A.; Smith, Benjamin D.

    2015-01-01

    IMPORTANCE The most appropriate dose-fractionation for whole breast irradiation (WBI) remains uncertain. OBJECTIVE To assess acute and six-month toxicity and quality of life (QoL) with conventionally fractionated WBI (CF-WBI) versus hypofractionated WBI (HF-WBI). DESIGN Unblinded randomized trial of CF-WBI (n=149; 50 Gy/25 fractions + boost [10–14 Gy/5–7 fractions]) versus HF-WBI (n=138; 42.56 Gy/16 fractions + boost [10–12.5 Gy/4–5 fractions]). SETTING Community-based and academic cancer centers. PARTICIPANTS 287 women age ≥ 40 years with stage 0–II breast cancer treated with breast-conserving surgery for whom whole breast irradiation without addition of a third field was recommended. 76% (n=217) were overweight or obese. Patients were enrolled from February 2011 through February 2014. INTERVENTION(S) FOR CLINICAL TRIALS CF-WBI versus HF-WBI. MAIN OUTCOME MEASURES Physician-reported acute and six-month toxicities using NCICTCv4.0 and patient-reported QoL using the FACT-B version 4. All analyses were intention-to-treat, with outcomes compared using chi-square, Cochran-Armitage test, and ordinal logistic regression. Patients were followed for a minimum of 6 months. RESULTS Treatment arms were well-matched for baseline characteristics including FACT-B total score (P=0.46) and individual QoL items such as lack of energy (P=0.86) and trouble meeting family needs (P=0.54). Maximal physician-reported acute dermatitis (P<0.001), pruritus (P<0.001), breast pain (P=0.001), hyperpigmentation (P=0.002), and fatigue (P=0.02) during radiation were lower in patients randomized to HF-WBI. Overall grade ≥2 acute toxicity was less with HF-WBI vs. CF-WBI (47% vs. 78%; P<0.001). Six months after radiation, physicians reported less fatigue in patients randomized to HF-WBI (P=0.01), and patients randomized to HF-WBI reported less lack of energy (P<0.001) and less trouble meeting family needs (P=0.01). Multivariable regression confirmed the superiority of HF-WBI in terms

  15. Numerical analysis of non-linear vibrations of a fractionally damped cylindrical shell under the conditions of combinational internal resonance

    Directory of Open Access Journals (Sweden)

    Rossikhin Yury A.

    2018-01-01

    Full Text Available Non-linear damped vibrations of a cylindrical shell embedded into a fractional derivative medium are investigated for the case of the combinational internal resonance, resulting in modal interaction, using two different numerical methods with further comparison of the results obtained. The damping properties of the surrounding medium are described by the fractional derivative Kelvin-Voigt model utilizing the Riemann-Liouville fractional derivatives. Within the first method, the generalized displacements of a coupled set of nonlinear ordinary differential equations of the second order are estimated using numerical solution of nonlinear multi-term fractional differential equations by the procedure based on the reduction of the problem to a system of fractional differential equations. According to the second method, the amplitudes and phases of nonlinear vibrations are estimated from the governing nonlinear differential equations describing amplitude-and-phase modulations for the case of the combinational internal resonance. A good agreement in results is declared.

  16. Biological alterations resulting from chronic lung irradiation. III. Effect of partial 60Co thoracic irradiation upon pulmonary collagen metabolism and fractionation in syrian hamsters

    International Nuclear Information System (INIS)

    Pickrell, J.A.; Harris, D.V.; Hahn, F.F.; Belasich, J.J.; Jones, R.K.

    1975-01-01

    Radiation-induced changes in pulmonary collagen metabolism were studied in Syrian hamsters given multiple thoracic doses of 60 Co radiation to achieve cumulative exposures of 6000, 4000, and 2000 R. At 13 to 14 wk after initial exposure, 6000- and 4000-R exposures had increased incorporation of injected [ 14 C]proline into pulmonary collagenous protein which suggested an increased collagen synthesis. By 21 to 22 wk after exposure, increased pulmonary soluble collagen was noted. Increased pulmonary scarring was indicated by a variable increase in native collagen at 13 to 36 wk. A collection of alveolar macrophages at 7 to 8 wk followed by inflammation at 13 to 14 wk and a beginning of pulmonary fibrosis at 13 to 19 wk were noted. At 21 to 22 wk after exposure a somewhat more marked pulmonary fibrosis and some epithelialization were observed. Hemosiderin deposits were also observed at 35 to 36 wk after exposure, but pathologic processes were lessened by this time. The early activation of collagen synthesis presumably caused the radiation-induced fibrosis. Later, when collagen tended to accumulate, the synthetic rate was normal. The activation of collagen synthesis caused by external thoracic irradiation resembles that caused by thoracic irradiation from the internal emitter, 144 Ce. Moreover, it demonstrates the usefulness of monitoring collagen biosynthesis by [ 14 C]proline incorporation into the lung. (U.S.)

  17. IAEA international database on irradiated nuclear graphite properties

    International Nuclear Information System (INIS)

    Burchell, T.D.; Clark, R.E.H.; Stephens, J.A.; Eto, M.; Haag, G.; Hacker, P.; Neighbour, G.B.; Janev, R.K.; Wickham, A.J.

    2000-02-01

    This report describes an IAEA database containing data on the properties of irradiated nuclear graphites. Development and implementation of the graphite database followed initial discussions at an IAEA Specialists' Meeting held in September 1995. The design of the database is based upon developments at the University of Bath (United Kingdom), work which the UK Health and Safety Executive initially supported. The database content and data management policies were determined during two IAEA Consultants' Meetings of nuclear reactor graphite specialists held in 1998 and 1999. The graphite data are relevant to the construction and safety case developments required for new and existing HTR nuclear power plants, and to the development of safety cases for continued operation of existing plants. The database design provides a flexible structure for data archiving and retrieval and employs Microsoft Access 97. An instruction manual is provided within this document for new users, including installation instructions for the database on personal computers running Windows 95/NT 4.0 or higher versions. The data management policies and associated responsibilities are contained in the database Working Arrangement which is included as an Appendix to this report. (author)

  18. IFMIF [International Fusion Materials Irradiation Facility], an accelerator-based neutron source for fusion components irradiation testing: Materials testing capabilities

    International Nuclear Information System (INIS)

    Mann, F.M.

    1988-08-01

    The International Fusion Materials Irradiation Facility (IFMIF) is proposed as an advanced accelerator-based neutron source for high-flux irradiation testing of large-sized fusion reactor components. The facility would require only small extensions to existing accelerator and target technology originally developed for the Fusion Materials Irradiation Test (FMIT) facility. At the extended facility, neutrons would be produced by a 0.1-A beam of 35-MeV deuterons incident upon a liquid lithium target. The volume available for high-flux (>10/sup 15/ n/cm/sup 2/-s) testing in IFMITF would be over a liter, a factor of about three larger than in the FMIT facility. This is because the effective beam current of 35-MeV deuterons on target can be increased by a factor of ten to 1A or more. Such an increase can be accomplished by funneling beams of deuterium ions from the radio-frequency quadruple into a linear accelerator and by taking advantage of recent developments in accelerator technology. Multiple beams and large total current allow great variety in available testing. For example, multiple simultaneous experiments, and great flexibility in tailoring spatial distributions of flux and spectra can be achieved. 5 refs., 2 figs., 1 tab

  19. Influence of geometrical parameters of the VVER-1000 reactor construction elements to internals irradiation conditions

    Directory of Open Access Journals (Sweden)

    О. M. Pugach

    2015-07-01

    Full Text Available Investigations to determine the influences of geometrical parameters of the calculational VVER-1000 reactor model to the results of internal irradiation condition determination are carried out. It is shown that the values of appropriate sensitivity matrix elements are not dependent on a height coordinate for any core level, but there is their azimuthal dependence. Maximum possible relative biases of neutron fluence due to inexact knowledge of internal geometrical parameters are obtained for the baffle and the barrel.

  20. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

    2015-08-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

  1. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    International Nuclear Information System (INIS)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E.

    2015-01-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm

  2. Effect of respiratory motion on internal radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Geneva Neuroscience Center, Geneva University, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB (Netherlands)

    2014-11-01

    Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences the absorbed dose for external exposure to radiation. However, to their knowledge, the effect of respiratory motion on internal radiation dosimetry has never been reported before. Methods: Thirteen computational models representing the adult male at different respiratory phases corresponding to the normal respiratory cycle were generated from the 4D dynamic XCAT phantom. Monte Carlo calculations were performed using the MCNP transport code to estimate the specific absorbed fractions (SAFs) of monoenergetic photons/electrons, the S-values of common positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124), and the absorbed dose of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in 28 target regions for both the static (average of dynamic frames) and dynamic phantoms. Results: The self-absorbed dose for most organs/tissues is only slightly influenced by respiratory motion. However, for the lung, the self-absorbed SAF is about 11.5% higher at the peak exhale phase than the peak inhale phase for photon energies above 50 keV. The cross-absorbed dose is obviously affected by respiratory motion for many combinations of source-target pairs. The cross-absorbed S-values for the heart contents irradiating the lung are about 7.5% higher in the peak exhale phase than the peak inhale phase for different positron-emitting radionuclides. For {sup 18}F-FDG, organ absorbed doses are less influenced by respiratory motion. Conclusions: Respiration-induced volume variations of the lungs and the repositioning of internal organs affect the self-absorbed dose of the lungs and cross-absorbed dose between organs in internal radiation dosimetry. The dynamic

  3. The effect of the overall treatment time of fractionated irradiation on the tumor control probability of a human soft tissue sarcoma xenograft in nude mice

    International Nuclear Information System (INIS)

    Allam, Ayman; Perez, Luis A.; Huang, Peigen; Taghian, Alphonse; Azinovic, Ignacio; Freeman, Jill; Duffy, Michael; Efird, Jimmy; Suit, Herman D.

    1995-01-01

    Purpose: To study the impact of the overall treatment time of fractionated irradiation on the tumor control probability (TCP) of a human soft tissue sarcoma xenograft growing in nude mice, as well as to compare the pretreatment potential doubling time (T pot ) of this tumor to the effective doubling time (T eff ) derived from three different schedules of irradiation using the same total number of fractions with different overall treatment times. Methods and Materials: The TCP was assessed using the TCD 50 value (the 50% tumor control dose) as an end point. A total of 240 male nude mice, 7-8 weeks old were used in three experimental groups that received the same total number of fractions (30 fractions) with different overall treatment times. In group 1, the animals received three equal fractions/day for 10 consecutive days, in group 2 they received two equal fractions/day for 15 consecutive days, and in group 3 one fraction/day for 30 consecutive days. All irradiations were given under normal blood flow conditions to air breathing animals. The mean tumor diameter at the start of irradiation was 7-8 mm. The mean interfraction intervals were from 8-24 h. The T pot was measured using Iododeoxyuridine (IudR) labeling and flow cytometry and was compared to T eff . Results: The TCD 50 values of the three different treatment schedules were 58.8 Gy, 63.2 Gy, and 75.6 Gy for groups 1, 2, and 3, respectively. This difference in TCD 50 values was significant (p pot (2.4 days) was longer than the calculated T eff in groups 2 and 3 (1.35 days). Conclusion: Our data show a significant loss in TCP with prolongation of the overall treatment time. This is most probably due to an accelerated repopulation of tumor clonogens. The pretreatment T pot of this tumor model does not reflect the actual doubling of the clonogens in a protracted regimen

  4. Clinical evaluation of the hypoxic cytotoxin tirapazamine (SR-4233): phase I experience with repeated dose administration during fractionated irradiation

    International Nuclear Information System (INIS)

    Hancock, Steven L.; Spencer, Sharon; Mariscal, Carol; Wooten, Ann; Wheeler, Richard; Brown, J. Martin; Fisher, Cheryl; Roemeling, Reinhard von

    1996-01-01

    Purpose: Regions of chronic or transient hypoxia are common in many human tumors and are thought to limit tumor cell killing and tumor control with conventional irradiation and some chemotherapeutic agents. Tirapazamine (3-amino-1,2,4-benzotriazine-1,4-di-N-oxide) forms a cytotoxic free radical during reductive metabolism in regions of hypoxia. In well oxygenated regions, the tirapazamine radical reacts with molecular oxygen to form the inactive parent drug. This results in markedly greater toxicity for hypoxic cells than for the well oxygenated cells that comprise most normal tissues. Tirapazamine increased the anti-tumor effects of single dose or fractionated irradiation or cis-platin chemotherapy in murine tumors,in vivo . This study evaluated the ability to repeat the administration of Tirapazamine during courses of fractionated irradiation in humans after an earlier phase I trial established a maximum tolerated dose of 390 mg per square meter of body surface area (mg/m 2 ) when given as a single dose with radiotherapy. Materials and Methods: Between December 1993 and August 1995 22 patients with locally advanced or metastatic tumors of varying histology, normal renal, hepatic, and hematologic functions, and Karnofsky performance status ≥ 60 received repeated doses of Tirapazamine during a planned, 6 weeks course of standardly fractionated radiotherapy. After anti-emetic treatment with ondansetron (32 mg) and dexamethasone (16 mg), Tirapazamine was administered during a 2 hour intravenous infusion that ended from 30 to 90 minutes before a radiation treatment. Patients were monitored for acute toxicity during the course of treatment and for a minimum of one month after radiotherapy. Results: The study was initiated with three, biweekly doses of Tirapazamine at 330 mg/m 2 . Four of 7 patients who initiated treatment at this dose refused the second (1 patient) or third dose of Tirapazamine (3 patients). Two of the three patients who received three doses

  5. Radiation-induced transformation of SV40-immortalized human thyroid epithelial cells by single and fractionated exposure to γ-irradiation in vitro

    International Nuclear Information System (INIS)

    Riches, A.C.; Herceg, Z.; Bryant, P.E.; Wynford-Thomas, D.

    1994-01-01

    Radiation-induced transformation of a human thyroid epithelial cell line (HTori-3) has been investigated following exposure to single and fractionated doses of γ-irradiation. The human epithelial cells were irradiated in vitro and following passaging, transplanted to the athymic nude mouse. Following a single exposure to γ-irradiation in the range 0.5-4Gy, 22 tumours were observed in 45 recipients and following three equal fractions in the range 0.5-4Gy per fraction, 18 tumours were observed in 31 recipients. Tumours were undifferentiated carcinomas and were observed from 7 to 20 weeks after transplantation. They occurred after similar radiation doses to those received by the children in the Belarus region of Ukraine, who developed thyroid tumours. The number of tumours observed, in each group receiving cells irradiated with a single dose of γ-irradiation in the range 0.5-4 Gy, was similar. Cell lines were established from some tumours and the tumorigenicity confirmed by retransplantation. These tumour cell lines were more radiosensitive than the human thyroid epithelial cell line they were derived from. This indicates that transformed cells were not being selected from a subpopulation within the parent cell line but that radiation-induced transformants were being induced de novo. The human origin of the tumours was established by karyotyping, immunocytochemical demonstration of human epithelial cytokeratins and p53 analysis. DNA fingerprinting confirmed that the tumours were derived from the original cell line. (author)

  6. Radioprotective efficacy of dipyridamole and AMP combination in fractionated radiation regimen, and its dependence on the time of administration of the drugs prior to irradiation

    International Nuclear Information System (INIS)

    Hofer, M.; Pospisil, M.; Netikova, J.; Hola, J.; Znojil, V.; Vacha, J.

    1995-01-01

    The authors have recently demonstrated that a combined administration of dipyridamole and adenosine monophosphate to mice induces radioprotective effects in terms of postirradiation hematopoietic recovery in animals irradiated with a single dose. The aim of the present experiments was to investigate the radioprotective ability of the drug combination under conditions of fractionated radiation. It was shown that administration of the drugs either 15 or 60 min before each of the five daily 3-Gy doses of gamma radiation enhances hematopoietic recovery and survival of mice exposed to an additional 'top-up' dose of 3.5 Gy. Furthermore, it was ascertained that administration of the drugs 60 min prior to irradiation is more effective than administration of the drugs 15 min prior to irradiation. Due to the evidence that administration of the drugs 15 min prior to irradiation protects the organism mainly via mechanisms of systemic hypoxia while the pretreatment 60 min before irradiation avoids the role of hypoxia and mainly induces cell proliferation effects, the present results suggest a more protective role of mechanisms stimulating hematopoiesis under conditions of fractionated radiation. The data may provide a basis for more rational use of radioprotection in fractionated radiation techniques. (author) 1 tab., 1 fig., 25 refs

  7. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine

    International Nuclear Information System (INIS)

    Gasinska, A.

    1995-01-01

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. α/β coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction α/β for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). α/β coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method α/β for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of α/β coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F r ) was much bigger for photons. For X-rays it was 50% for early and 63% for late effects. In case of

  8. The enhancing effect of fractionated whole-body x-irradiation on replication of endogenous leukemia viruses in BALB/c mice

    International Nuclear Information System (INIS)

    Takamori, Yasuhiko; Okumoto, Masaaki; Iwai, Mineko; Iwai, Yoshiaki

    1976-01-01

    The incidence of leukemia, changes in the tissue weight of spleen and thymus, and the expression of endogenous viruses were examined with BALB/c mice following 4 weekly fractionated whole-body x-irradiation of 170 R each, starting at 4 weeks of age. The leukemia incidence was quite low for the unirradiated controls, while 60% of the irradiated male mice developed thymic lymphoma. The virus-positive cells appeared earlier in the spleen than in the thymus and bone marrow, and increased with aging. The time of appearance of virus-positive cells in these tissues was remarkably promoted by the fractionated x-irradiation, and its frequency was also enhanced. (auth.)

  9. Dielectric parameters of blood plasma in rats at external and internal irradiation with sublethal doses

    International Nuclear Information System (INIS)

    Khadzhidekova, E.; Kiradzhiev, G.

    1991-01-01

    Sexually mature male rats have received external gamma irradiation with 50, 200 or 380 cGy, treated with 89 Sr (333 or 1665 kBq per rat, femur dose 70, resp. 290 cGy), or 144 Ce (370 kBq per rat, liver dose 70 cGy). Dielectric parameters (permittivity and conductivity) have been measured in the frequency range 1.4 - 17 Mhz on different terms (1 to 30th day after the treatment). For all groups and terms the coefficients and equations describing the relationship between the dielectric permittivity ε and the frequency ν of the changing electric field have been calculated. On the basis of dielectric parameters the relaxation time of the plasma protein molecules is determined. It has been shown that the changes in dielectric permittivity are expressed at different frequencies specific for a given dose; the same is established for the conditions of internal irradiation. The frequency dependence of the permittivity is described as an exponential curve analogous to that of the control but with a changed exponent. In applying higher doses or activities the relationship turns from exponential to parabolic. The relaxation time, expressing the changes in conformal state of macromolecules, varies but is in all cases longer than one of the controls for the whole period of study at external irradiation with 50 and 380 cGy. It is lower at irradiation with 200 cGy, as well as at internal irradiation. 3 tabs., 13 refs

  10. A generalised formulation of the 'incomplete-repair' model for cell survival and tissue response to fractionated low dose-rate irradiation

    International Nuclear Information System (INIS)

    Nilsson, P.; Joiner, M.C.

    1990-01-01

    A generalized equation for cell survival or tissue effects after fractionated low dose-rate irradiations, when there is incomplete repair between fractions and significant repair during fractions, is derived in terms of the h- and g-functions of the 'incomplete-repair' (IR) model. The model is critically dependent on α/β, repair half-time, treatment time and interfraction interval, and should therefore be regarded primarily as a tool for the analysis of fractionation and dose-rate effects in carefully designed radiobiological experiments, although it should also be useful in exploring, in a general way, the feasibility of clinical treatment protocols using fractionated low dose-rate treatments. (author)

  11. The effect of pentoxifylline on early and late radiation injury following fractionated irradiation in C3H mice

    Energy Technology Data Exchange (ETDEWEB)

    Dion, M.W.; Hussey, D.H.; Osborne, J.W.

    1989-07-01

    An experiment was performed to test the effectiveness of pentoxifylline in reducing late radiation injury. One hundred and four C3H mice were randomized into eight groups of 13 mice each, and the right hind limbs were irradiated with 4000, 5000, 6000, or 7000 cGy in ten fractions. Each group was treated with once daily injections of either pentoxifylline or saline for 30+ weeks. An additional ten mice received daily injections of pentoxifylline or saline, but no irradiation. The pentoxifylline animals demonstrated significantly less late injury than the saline treated animals. The most obvious differences were observed in the 5000 and 6000 cGy groups. There were seven radiation related deaths in the saline treated control groups, but only one radiation related death in the pentoxifylline treated groups. Whereas 42% (20/48) of the saline treated animals had a late injury score of 3.0 or greater, only 8% (4/51) of the pentoxifylline treated animals had a late skin score as high as 3.0. Pentoxifylline had no effect on the acute radiation injury scores. The drug was well tolerated with no toxic effects noted. Pentoxifylline is a methyl xanthine derivative that is used to treat vascular occlusive disease in humans. It improves perfusion through small capillaries by improving the deformability of red blood cells, inhibiting platelet aggregation, and stimulating the release of prostacyclin. This study shows that the prophylactic administration of pentoxifylline can modify late radiation induced injury in the mouse extremity. It may have value in the prevention or treatment of late radiation induced injury in humans, and it could be a useful tool to help define the mechanisms of late radiation injury in specific organs.

  12. The effect of pentoxifylline on early and late radiation injury following fractionated irradiation in C3H mice

    International Nuclear Information System (INIS)

    Dion, M.W.; Hussey, D.H.; Osborne, J.W.

    1989-01-01

    An experiment was performed to test the effectiveness of pentoxifylline in reducing late radiation injury. One hundred and four C3H mice were randomized into eight groups of 13 mice each, and the right hind limbs were irradiated with 4000, 5000, 6000, or 7000 cGy in ten fractions. Each group was treated with once daily injections of either pentoxifylline or saline for 30+ weeks. An additional ten mice received daily injections of pentoxifylline or saline, but no irradiation. The pentoxifylline animals demonstrated significantly less late injury than the saline treated animals. The most obvious differences were observed in the 5000 and 6000 cGy groups. There were seven radiation related deaths in the saline treated control groups, but only one radiation related death in the pentoxifylline treated groups. Whereas 42% (20/48) of the saline treated animals had a late injury score of 3.0 or greater, only 8% (4/51) of the pentoxifylline treated animals had a late skin score as high as 3.0. Pentoxifylline had no effect on the acute radiation injury scores. The drug was well tolerated with no toxic effects noted. Pentoxifylline is a methyl xanthine derivative that is used to treat vascular occlusive disease in humans. It improves perfusion through small capillaries by improving the deformability of red blood cells, inhibiting platelet aggregation, and stimulating the release of prostacyclin. This study shows that the prophylactic administration of pentoxifylline can modify late radiation induced injury in the mouse extremity. It may have value in the prevention or treatment of late radiation induced injury in humans, and it could be a useful tool to help define the mechanisms of late radiation injury in specific organs

  13. Tangential breast irradiation with or without internal mammary chain irradiation: results of a randomized trial

    International Nuclear Information System (INIS)

    Kaija, Holli; Maunu, Pitkaenen

    1995-01-01

    A prospective randomized study was made of 270 patients with unilateral stage I or II invasive breast cancer treated by segmental resection, axillary dissection and radiation at the University Hospital of Tampere, Finland, between 1989 and 1991. The aim of the study was to determine whether there is any advantage or disadvantage if the internal mammary chains (IMC) are included in the radiation target volume. The medial and lateral two-field technique was used and the target volumes were determined randomly either to include the internal mammary chain (IMC-RT) or not (no-IMC-RT). The prevalence of radiation pneumonitis was 16% and there was no significant difference between the IMC- and no-IMC-groups (18 vs. 14%). Skin reactions were equal in both groups. Lung fibrosis was more common in the IMC-RT group. In conclusion: radiation of internal mammary chain after conservative surgery does not lead to an increase in clinically important skin or pulmonary complications. Whether it prevents recurrences or new primaries of the opposite breast is too early to say because of the short follow-up time

  14. Improving external beam radiotherapy by combination with internal irradiation.

    Science.gov (United States)

    Dietrich, A; Koi, L; Zöphel, K; Sihver, W; Kotzerke, J; Baumann, M; Krause, M

    2015-07-01

    The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed.

  15. A secretome analysis reveals that PPARα is upregulated by fractionated-dose γ-irradiation in three-dimensional keratinocyte cultures

    International Nuclear Information System (INIS)

    Lee, Jee Yong; Kim, Hyun Ji; Yi, Jae Youn

    2016-01-01

    A three-dimensional (3D) environment composed of properly interconnected and differentiated cells that allows communication and cooperation among cells via secreted molecules would be expected to more accurately reflect cellular responses. Here, we investigated γ-irradiation-induced changes in the secretome of 3D-cultured keratinocytes. An analysis of keratinocyte secretome profiles following fractionated-dose γ-irradiation revealed changes in genes involved in cell adhesion, angiogenesis, and the immune system. Notably, peroxisome proliferator-activated receptor-(PPARα) was upregulated in response to fractionated-dose γ-irradiation. This upregulation was associated with an increase in the transcription of known PPARα target genes, including angiopoietin-like protein 4, dermokine and kallikrein-related peptide 12, which were differentially regulated by fractionated-dose γ-irradiation. Collectively, our data imply a mechanism linking γ-irradiation and secretome changes, and suggest that these changes could play a significant role in the coordinated cellular responses to harmful ionizing radiation, such as those associated with radiation therapy. This extension of our understanding of γ-irradiation-induced secretome changes has the potential to improve radiation therapy strategies. Control of inflammatory waves, improved wound healing, and stabilization of the skin barrier are imperative for minimizing such injuries. Therefore, PPARα agonists and antagonists have the potential to become important therapeutic agents for the treatment of γ-irradiation induced skin damage. Specifically, our analysis suggests that the undesirable consequences of long-term exposure to ionizing radiation could be alleviated by PPARα agonists

  16. A secretome analysis reveals that PPARα is upregulated by fractionated-dose γ-irradiation in three-dimensional keratinocyte cultures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jee Yong; Kim, Hyun Ji; Yi, Jae Youn [Korea Institute of Radiation and Medical Sciences, Daejeon (Korea, Republic of)

    2016-05-15

    A three-dimensional (3D) environment composed of properly interconnected and differentiated cells that allows communication and cooperation among cells via secreted molecules would be expected to more accurately reflect cellular responses. Here, we investigated γ-irradiation-induced changes in the secretome of 3D-cultured keratinocytes. An analysis of keratinocyte secretome profiles following fractionated-dose γ-irradiation revealed changes in genes involved in cell adhesion, angiogenesis, and the immune system. Notably, peroxisome proliferator-activated receptor-(PPARα) was upregulated in response to fractionated-dose γ-irradiation. This upregulation was associated with an increase in the transcription of known PPARα target genes, including angiopoietin-like protein 4, dermokine and kallikrein-related peptide 12, which were differentially regulated by fractionated-dose γ-irradiation. Collectively, our data imply a mechanism linking γ-irradiation and secretome changes, and suggest that these changes could play a significant role in the coordinated cellular responses to harmful ionizing radiation, such as those associated with radiation therapy. This extension of our understanding of γ-irradiation-induced secretome changes has the potential to improve radiation therapy strategies. Control of inflammatory waves, improved wound healing, and stabilization of the skin barrier are imperative for minimizing such injuries. Therefore, PPARα agonists and antagonists have the potential to become important therapeutic agents for the treatment of γ-irradiation induced skin damage. Specifically, our analysis suggests that the undesirable consequences of long-term exposure to ionizing radiation could be alleviated by PPARα agonists.

  17. Proof of radiation-induced tumour TNF-α expression in Ewing sarcoma cell line RM-82 following clinically relevant in vitro fractionated irradiation and in vivo one-time irradiation

    International Nuclear Information System (INIS)

    Litzenberger, K.; Ruebe, C.E.; Erren, M.; Liu, L.; Valen, F. van; Palm, J.; Yang, K.; Ruebe, C.

    2004-01-01

    The purpose of the present study was to investigate the influence of fractionated irradiation on TNF-α expression in Ewing sarcoma cell line RM-82 in vitro and following its establishment as a xenograft tumour in the nude mouse in vivo [de

  18. Histological examination of the oral mucosa after fractional diode laser irradiation with different power and pulse duration

    Science.gov (United States)

    Belikov, Andrey V.; Ermolaeva, Ludmila A.; Korzhevsky, Dmitriy E.; Sergeeva, Elena S.; Semyashkina, Yulia V.; Antropova, Maria M.; Fedotov, Denis Y.; Zaitseva, Maria A.; Kashina, Tatiana V.

    2018-04-01

    Optical and histological methods were used to examination of influence the power and pulse duration of 980-nm diode laser to the dimensions and morphology of tissue around fractional micro injuries created by the radiation of that laser in the oral mucosa of rats in vivo. The power of laser radiation (P) varied in the range of 1÷21 W, and its pulse duration (tp) - in the range 50÷500 ms. Histological examination showed that in the mucosa of the oral cavity after the laser fractional irradiation, there following effects are found: a tissue defect, a transudate in the lumen of ablative micro injury, stretching and compacting effect of the nuclei of the basal epithelium, the disappearance of granules of the keratohialin, destroying the structure of the connective tissue, erythrocyte stasis in the vessels, the disappearance of transverse striation in the muscle fibers in muscle layer. It has been found that ablative micro injury begins to form up at P = 5 W, tp = 100 ms and affects only the epithelial layer of the mucosa. At P = 7 W, tp = 120 ms, the ratio of width to depth of ablative micro injury is 1 : 1, and at P = 10 W, tp = 100 ms, an ablative micro column with ratio of 1 : 1.5 is formed in the epithelial and submucosal layers of the mucosa. The laser effect with P = 15 W, tp = 200 ms leads to lengthening of the ablation micro-column to 1 : 2, with the bottom of the ablative micro column reaching the muscular layer. With a further growth of laser power or pulse duration, the width of the micro injury increases, and the growth of the micro injury depth is slowed down so that the micro column buildup is ceased.

  19. Internal friction measurements of Mo after low-temperature proton irradiation

    International Nuclear Information System (INIS)

    Tanimoto, H.; Mizubayashi, H.; Masuda, R.; Okuda, S.; Tagishi, Y.

    1992-01-01

    Internal friction measurements are performed in Mo after 20 MeV proton irradiation in order to clarify the behavior of self-interstitial atoms (SIA's) in Mo. In the low dose range, strong dislocation pinning suggesting the free migration of defects is observed at about 40 K and weak pinning at about 25 K. The features are very similar to those reported after neutron irradiation except that the 25 K pinning is much smaller after proton irradiation. The result suggests that the migration of free SIA's is responsible for the 40 K pinning and that of SIA-defect clusters, probably di-SIA's, formed during irradiation for the 25 K pinning. In the high dose range, the relaxation peaks are observed at about 13 and 41 K, where the close similarities are found between the present peaks and the corresponding peaks reported after neutron irradiation except that the peak height of the 41 K peak per unit concentration of Frenkel pairs (FP) tends to increase strongly with decreasing dose here. The latter fact suggests the strong interaction between SIA's. Then the smallness of the 41 K peak reported after electron irradiation with very high dose could be explained by an increased interaction between SIA's, but not by the two-dimensional migration of SIA's as proposed by Jacques and Robrock. Deformation given prior to irradiation causes a drastic decrease in the modulus defects associated with FP's (so-called bulk effect) and in the 13 K peak height. After neutron irradiation, no such effect of deformation was reported. A possible origin for this difference is discussed. (orig.)

  20. Internal irradiation with radon daughters in some Bulgarian polymetal mines over the period 1962-1993

    International Nuclear Information System (INIS)

    Presiyanov, D.; Dimotrov, M.

    1993-01-01

    The results of radiation monitoring of the working environment in the Bulgarian metal mines are evaluated. The irradiation levels in the Burgas Copper Mines and their variations over the years have been estimated. A radiological characteristic of the working environment is provided together with a risk assessment for workers in different mines. A retrospective risk assessment is attempted for mines where increased radon 222 levels have been detected recently. The organization of radiometric monitoring and measures to limit the risk of internal irradiation are discussed. (author)

  1. The effect of the overall treatment time of fractionated irradiation on the tumor control probability of a human soft tissue sarcoma xenograft in nude mice

    Energy Technology Data Exchange (ETDEWEB)

    Allam, Ayman; Perez, Luis A; Huang, Peigen; Taghian, Alphonse; Azinovic, Ignacio; Freeman, Jill; Duffy, Michael; Efird, Jimmy; Suit, Herman D

    1995-04-30

    Purpose: To study the impact of the overall treatment time of fractionated irradiation on the tumor control probability (TCP) of a human soft tissue sarcoma xenograft growing in nude mice, as well as to compare the pretreatment potential doubling time (T{sub pot}) of this tumor to the effective doubling time (T{sub eff}) derived from three different schedules of irradiation using the same total number of fractions with different overall treatment times. Methods and Materials: The TCP was assessed using the TCD{sub 50} value (the 50% tumor control dose) as an end point. A total of 240 male nude mice, 7-8 weeks old were used in three experimental groups that received the same total number of fractions (30 fractions) with different overall treatment times. In group 1, the animals received three equal fractions/day for 10 consecutive days, in group 2 they received two equal fractions/day for 15 consecutive days, and in group 3 one fraction/day for 30 consecutive days. All irradiations were given under normal blood flow conditions to air breathing animals. The mean tumor diameter at the start of irradiation was 7-8 mm. The mean interfraction intervals were from 8-24 h. The T{sub pot} was measured using Iododeoxyuridine (IudR) labeling and flow cytometry and was compared to T{sub eff}. Results: The TCD{sub 50} values of the three different treatment schedules were 58.8 Gy, 63.2 Gy, and 75.6 Gy for groups 1, 2, and 3, respectively. This difference in TCD{sub 50} values was significant (p < 0.05) between groups 1 and 2 (30 fractions/10 days and 30 fractions/15 days) vs. group 3 (30 fractions/30 days). The loss in TCP due to the prolongation of the overall treatment time from 10 days to 30 days was found to be 1.35-1.4 Gy/day. The pretreatment T{sub pot} (2.4 days) was longer than the calculated T{sub eff} in groups 2 and 3 (1.35 days). Conclusion: Our data show a significant loss in TCP with prolongation of the overall treatment time. This is most probably due to an

  2. Molecular and genetic approach to understanding the mechanisms by which fractionated X-irradiation induces leukemia in mice

    Energy Technology Data Exchange (ETDEWEB)

    Meruelo, D; Rossomando, A

    1986-01-01

    The authors laboratory's approach to try to shed light on the question of a viral etiology for radiation-induced leukemia has focused on defining, localizing and understanding the mode of action of genes involved in susceptibility to fractionated x-irradiation-(FXI) induced disease. These studies have indicated that multiple genes control the process of leukemogenesis. Not every mouse strain which shows some susceptibility to FXI-induced leukemia carries the susceptible gene at each of the multiple loci involved in the disease process. It is plausible to conclude that more than one mechanism of leukemogenesis can be triggered by FXI. Studies have focused on the mode of action of one such locus Ril-1. Several reagents have been developed to help clone and characterize this locus. Currently chromosomal ''walking'' and ''hopping'' techniques are being used in conjunction with an RFLP molecular probe which is adjacent to Ril-1. In addition a cDNA library has been prepared from a radiation-induced thymoma and substraction hybridization analysis is being used in the search for Ril-1.

  3. A molecular and genetic approach to understanding the mechanisms by which fractionated X-irradiation induces leukemia in mice

    International Nuclear Information System (INIS)

    Meruelo, D.; Rossomando, A.

    1986-01-01

    The authors laboratory's approach to try to shed light on the question of a viral etiology for radiation-induced leukemia has focused on defining, localizing and understanding the mode of action of genes involved in susceptibility to fractionated x-irradiation-(FXI) induced disease. These studies have indicated that multiple genes control the process of leukemogenesis. Not every mouse strain which shows some susceptibility to FXI-induced leukemia carries the susceptible gene at each of the multiple loci involved in the disease process. It is plausible to conclude that more than one mechanism of leukemogenesis can be triggered by FXI. Studies have focused on the mode of action of one such locus Ril-1. Several reagents have been developed to help clone and characterize this locus. Currently chromosomal ''walking'' and ''hopping'' techniques are being used in conjunction with an RFLP molecular probe which is adjacent to Ril-1. In addition a cDNA library has been prepared from a radiation-induced thymoma and substraction hybridization analysis is being used in the search for Ril-1. (author)

  4. High-Dose, Single-Fraction Irradiation Rapidly Reduces Tumor Vasculature and Perfusion in a Xenograft Model of Neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Jani, Ashish; Shaikh, Fauzia; Barton, Sunjay [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States); Willis, Callen [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Banerjee, Debarshi [Department of Pediatrics, Columbia University Medical Center, New York, New York (United States); Mitchell, Jason [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Hernandez, Sonia L. [Department of Surgery, University of Chicago, Chicago, Illinois (United States); Hei, Tom [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States); Kadenhe-Chiweshe, Angela [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Yamashiro, Darrell J. [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Department of Pediatrics, Columbia University Medical Center, New York, New York (United States); Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York (United States); Connolly, Eileen P., E-mail: epc2116@cumc.columbia.edu [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States)

    2016-04-01

    Purpose: To characterize the effects of high-dose radiation therapy (HDRT) on neuroblastoma tumor vasculature, including the endothelial cell (EC)–pericyte interaction as a potential target for combined treatment with antiangiogenic agents. Methods and Materials: The vascular effects of radiation therapy were examined in a xenograft model of high-risk neuroblastoma. In vivo 3-dimensional contrast-enhanced ultrasonography (3D-CEUS) imaging and immunohistochemistry (IHC) were performed. Results: HDRT significantly reduced tumor blood volume 6 hours after irradiation compared with the lower doses used in conventionally fractionated radiation. There was a 63% decrease in tumor blood volume after 12-Gy radiation compared with a 24% decrease after 2 Gy. Analysis of tumor vasculature by lectin angiography showed a significant loss of small vessel ends at 6 hours. IHC revealed a significant loss of ECs at 6 and 72 hours after HDRT, with an accompanying loss of immature and mature pericytes at 72 hours. Conclusions: HDRT affects tumor vasculature in a manner not observed at lower doses. The main observation was an early reduction in tumor perfusion resulting from a reduction of small vessel ends with a corresponding loss of endothelial cells and pericytes.

  5. Oxidative quality of commercial fried nuts: evaluation of a surface and an internal lipid fraction

    Directory of Open Access Journals (Sweden)

    Dobarganes, M. C.

    2006-09-01

    Full Text Available The oxidative quality of commercial fried nuts was evaluated by independent analyses of two lipid fractions, the surface oil, and the internal lipid fraction. The nuts studied were 6 samples of almonds, 10 samples of peanuts, 4 samples of sunflower seeds and 2 samples of cashew nuts. The oil content, peroxide value, polymer content, and fatty acid composition were analyzed. The results showed two lipid fractions with different oxidation status. Higher oxidation levels were normally found in the oil fraction more exposed  to air, although considerably higher oxidation status in the internal oil was also detected in various samples. Oxidative quality was also evaluated in selected samples of each nut after 1 year of storage at room temperature, in the dark . Only the almonds and cashew nuts exhibited acceptable oxidative quality after storage. In addition, a study on the changes due to frying and the contribution of the frying oil to the lipids in the final product showed that the composition of the surface oil can be changed by the incorporation of substantial contents of the frying fat. Consequently, the frying fat may exert some effect on the oxidative quality and oxidative stability of the surface oil.En este estudio se evalúa la calidad oxidativa de muestras comerciales de frutos secos fritos mediante el análisis independiente de dos fracciones lipídicas, el aceite superficial, fácilmente extraíble con disolventes orgánicos, y la fracción de lípidos internos. Las muestras estudiadas fueron 6 muestras de almendras, 10 muestras de cacahuetes, 4 muestras de pipas de girasol y 2 muestras de anacardos. Se analizaron el contenido de aceite, el índice de peróxidos, el contenido de polímeros y la composición de ácidos grasos. Los resultados mostraron dos fracciones lipídicas con diferente estado de oxidación. Mayores niveles de oxidación fueron normalmente encontrados en la fracción más expuesta al aire, aunque estados de oxidaci

  6. Fractionation study: survival of mouse intestinal crypts to exposure of 60Co and 11 MeV electrons

    International Nuclear Information System (INIS)

    Coffey, C.W.

    1975-01-01

    The study was conducted to determine a statistical procedure for the quantification of time, dose, fraction relations for mouse intestinal crypt survival after fractionated Co-60 and 11-MeV electron irradiation. In the initial phase of the investigation CDF/1 male mice were exposed to fractionated Co-60 irradiation. A completely randomized experimental design with three factors, total time from initiation to completion of fractionation schedule, number of fractions, and total dose was utilized. The experimental animals were irradiated with a Co-60 panoramic irradiator unit at an absorbed dose rate of approximately 51 rads per minute. Two days after completion of the fractionation schedule, the experimental animals were sacrificed by cervical dislocation. Sections of intestinal jejunum were resected and routine histological preparations performed. The surviving crypts were scored with a compound microscope using a quantitative counting technique. The resulting crypt survival was observed to increase for increasing total times and fraction numbers

  7. Low temperature internal friction on γ-irradiated polyvinylidene fluoride (PVDF)

    International Nuclear Information System (INIS)

    Callens, A.; Eersels, L.; De Batist, R.

    1978-01-01

    A least-squares fitting of the below room temperature part of the internal friction spectra, obtained by the torsion pendulum technique on as-received and γ-irradiated (up to 1 Grad) strips and fibres of polyvinylidene fluoride by a superposition of single Debye functions, reveals that the spectral component features are determined not only by purely amorphous chain characteristics but also by the dose-dependence of crystallinity. A careful analysis of the relaxation spectra confirms that at least one relaxation effect (approximately 236 K) is created upon irradiation. The analysis of the dose dependence of the characteristics of the β (glass transition; approximately 220 K) and βsub(u) (apparent upper glass transition; approximately 270 K) relaxations, suggests the probable influence of crystallinity on the molecular motion in the amorphous phase. The increase of the intensity of the γ relaxation (approximately 190 K) is related to the irradiation-induced crystallite degradation. (author)

  8. Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kabaya, Koji; Watanabe, Masahiko; Kusaka, Masaru; Seki, Masatoshi (Kirin Brewery Co., Ltd., Gunma (Japan). Pharmaceutical Research Laboratory); Fushiki, Masato

    1994-08-01

    The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 [mu]g/body/day from day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also reveals an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation. (author).

  9. Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice

    International Nuclear Information System (INIS)

    Kabaya, Koji; Watanabe, Masahiko; Kusaka, Masaru; Seki, Masatoshi; Fushiki, Masato.

    1994-01-01

    The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 μg/body/day from day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also reveals an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation. (author)

  10. International Fusion Materials Irradiation Facility conceptual design activity. Present status and perspective

    International Nuclear Information System (INIS)

    Kondo, Tatsuo; Noda, Kenji; Oyama, Yukio

    1998-01-01

    For developing the materials for nuclear fusion reactors, it is indispensable to study on the neutron irradiation behavior under fusion reactor conditions, but there is not any high energy neutron irradiation facility that can simulate fusion reactor conditions at present. Therefore, the investigation of the IFMIF was begun jointly by Japan, USA, Europe and Russia following the initiative of IEA. The conceptual design activities were completed in 1997. As to the background and the course, the present status of the research on heavy irradiation and the testing means for fusion materials, the requirement and the technical basis of high energy neutron irradiation, and the international joint design activities are reported. The materials for fusion reactors are exposed to the neutron irradiation with the energy spectra up to 14 MeV. The requirements from the users that the IFMIF should satisfy, the demand of the tests for the materials of prototype and demonstration fusion reactors and the evaluation of the neutron field characteristics of the IFMIF are discussed. As to the conceptual design of the IFMIF, the whole constitution, the operational mode, accelerator system and target system are described. (K.I.)

  11. Irradiation experiments on materials for core internals, pressure vessel and fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Materials degradation due to the aging phenomena is one of the key issues for the life assessment and extension of the light water reactors (LWRs). This presentation introduces JAERI`s activities in the field of LWR material researches which utilize the research and testing reactors for irradiation experiments. The activities are including the material studies for the core internals, pressure vessel and fuel cladding. These materials are exposed to the neutron/gamma radiation and high temperature water environments so that it is worth reviewing their degradation phenomena as the continuum. Three topics are presented; For the core internal materials, the irradiation assisted stress corrosion cracking (IASCC) of austenitic stainless steels is the present major concern. At JAERI the effects of alloying elements on IASCC have been investigated through the post-irradiation stress corrosion cracking tests in high-temperature water. The radiation embrittlement of pressure vessel steels is still a significant issue for LWR safety, and at JAERI some factors affecting the embrittlement behavior such as a dose rate have been investigated. Waterside corrosion of Zircaloy fuel cladding is one of the limiting factors in fuel rod performance and an in-situ measurement of the corrosion rate in high-temperature water was performed in JMTR. To improve the reliability of experiments and to extent the applicability of experimental techniques, a mutual utilization of the technical achievements in those irradiation experiments is desired. (author)

  12. Weekly bi-fractionated 40 Gy three-dimensional conformational accelerated partial irradiation of breast: results of a phase II French pilot study

    International Nuclear Information System (INIS)

    Bourgier, C.; Pichenot, C.; Verstraet, R.; Heymann, S.; Biron, B.; Delaloge, S.; Garbay, J.R.; Marsiglia, H.; Bourhis, J.; Taghian, A.; Marsiglia, H.

    2010-01-01

    The authors report the first French experience of three-dimensional conformational and accelerated partial irradiation of breast. Twenty five patients have been concerned by this phase II trial. The prescribed total dose was 40 Gy, was delivered over 5 days in two daily fractions. Irradiation was performed with two 6 MV tangential mini-beams and a 6-22 MeV front electron beams. The planning target volume coverage was very good. Toxicity has been assessed. Healthy tissues (heart, lungs) are considerably protected. The acute and late toxicity is correct. Short communication

  13. Internal irradiation by radon daughters in Bulgarian uranium mines over the period 1956-1990

    International Nuclear Information System (INIS)

    Dimitrov, M.; Presiyanov, D.

    1993-01-01

    The results of over 30-years' radiation monitoring in Bulgarian uranium mines are summed up in retrospect. The overall organization and the parameters monitored during the different periods are discussed. A radiological characteristic of the working environment is presented which includes radon and its decay products. The internal irradiation levels during different time periods and in different mines have been estimated. The health costs of uranium mining in Bulgaria are discussed and conclusions and recommendations for radiological control are made. (author)

  14. International fusion materials irradiation facility and neutronic calculations for its test modules

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.

    1997-01-01

    The International Fusion Material Irradiation Facility (IFMIF) is a projected high intensity neutron source for material testing. Neutron transport calculations for the IFMIF project are performed for variety of here explained reasons. The results of MCNP neutronic calculations for IFMIF test modules with NaK and He cooled high flux test cells are presented in this paper. (author). 3 refs., 2 figs., 3 tabs

  15. Sound Absorbers

    Science.gov (United States)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  16. Kinetics of the absorbed dose formation and the effect of chronic β-irradiation on the cytogenetic characteristics and harvest of barley plants

    International Nuclear Information System (INIS)

    Zyablitskaya, E.Ya.; Kal'chenko, V.A.; Aleksakhin, R.M.; Zuev, N.D.

    1984-01-01

    A study was made of the kinetics of the absorbed dose formation, of the cytogenetic effects and the yield of barley plants growing in the experimental fields artificially contaminated with 90 Sr- 90 Y. It was shown that 70% of the dose absorbed during the vegetation period fall on the 1st and the and stages of organogenesis. The dose absorbed was shown to increase the cytogenetic effects. As calculated per 1 Gy the cytogenetic effects had an inverse relation to the dose rate

  17. Development of irradiation techniques and assessment of tumor response carbon ion radiotherapy in ultra-short fraction and time for a small lung cancer

    International Nuclear Information System (INIS)

    Baba, Masayuki; Miyamoto, Tadaaki; Sugawara, Toshiyuki

    2005-01-01

    For planning safety carbon therapy for lung cancer, the minimum (threshold) dose to generate lung reaction on CT image was investigated at each fraction regimen. From 1995 January to 2003 December, 44 patients with stage I non-small cell lung cancer who were treated with carbon ion beams of various fractions (1-12 fractions a port) and total doses (28-90 GyE). The 78 irradiated fields for the early reaction (within 6 months) and 67 for the late (1 year after) were divided into the two groups: the positive (+) and the negative (-) after the reactions on CT image were graded according to Libshits's criteria. The α/βvalue of biological effective dose (BED) responsive curve was determined by assuming the biserial correlation coefficient between positive rate of lung reaction and BED dose. From the BED responsive curve, in turn, the dose responsive curve for lung reaction rate at each fraction regimen was obtained. Based on the curve, D10 (to generate the lung reaction at 10% of the patients) in single fraction regimen was determined to be 10.6 GyE for the late reaction and 9.96 GyE for the early reaction, respectively. These doses seem to be very useful to estimate lung injuries in singe-dose irradiation. (author)

  18. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Executive summary

    International Nuclear Information System (INIS)

    1997-01-01

    This report is a summary of the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member

  19. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This report is a summary of the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member.

  20. Internal stress distribution for generating closure domains in laser-irradiated Fe–3%Si(110) steels

    International Nuclear Information System (INIS)

    Iwata, Keiji; Imafuku, Muneyuki; Orihara, Hideto; Sakai, Yusuke; Ohya, Shin-Ichi; Suzuki, Tamaki; Shobu, Takahisa; Akita, Koichi; Ishiyama, Kazushi

    2015-01-01

    Internal stress distribution for generating closure domains occurring in laser-irradiated Fe–3%Si(110) steels was investigated using high-energy X-ray analysis and domain theory based on the variational principle. The measured triaxial stresses inside the specimen were compressive and the stress in the rolling direction became more dominant than stresses in the other directions. The calculations based on the variational principle of magnetic energy for closure domains showed that the measured triaxial stresses made the closure domains more stable than the basic domain without closure domains. The experimental and calculation results reveal that the laser-introduced internal stresses result in the occurrence of the closure domains

  1. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    International Nuclear Information System (INIS)

    Martone, M.

    1997-01-01

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member

  2. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Martone, M [ENEA, Centro Ricerche Frascati, Rome (Italy)

    1997-01-01

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member.

  3. High-dose total-body irradiation and autologous marrow reconstitution in dogs: dose-rate-related acute toxicity and fractionation-dependent long-term survival

    International Nuclear Information System (INIS)

    Deeg, H.J.; Storb, R.; Weiden, P.L.; Schumacher, D.; Shulman, H.; Graham, T.; Thomas, E.D.

    1981-01-01

    Beagle dogs treated by total-body irradiation (TBI) were given autologous marrow grafts in order to avoid death from marrow toxicity. Acute and delayed non-marrow toxicities of high single-dose (27 dogs) and fractionated TBI (20 dogs) delivered at 0.05 or 0.1 Gy/min were compared. Fractionated TBI was given in increments of 2 Gy every 6 hr for three increments per day. Acute toxicity and early mortality (<1 month) at identical total irradiation doses were comparable for dogs given fractionated or single-dose TBI. With single-dose TBI, 14, 16, and 18 Gy, respectively, given at 0.05 Gy/min, 0/5, 5/5, and 2/2 dogs died from acute toxicity; with 10, 12, and 14 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 5/5 dogs died acutely. With fractionated TBI, 14 and 16 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 2/2 dogs died auctely. Early deaths were due to radiation enteritis with or without associated septicemia (29 dogs; less than or equal to Day 10). Three dogs given 10 Gy of TBI at 0.1 Gy/min died from bacterial pneumonia; one (Day 18) had been given fractionated and two (Days 14, 22) single-dose TBI. Fifteen dogs survived beyond 1 month; eight of these had single-dose TBI (10-14 Gy) and all died within 7 months of irradiation from a syndrome consisting of hepatic damage, pancreatic fibrosis, malnutrition, wasting, and anemia. Seven of the 15 had fractionated TBI, and only one (14 Gy) died on Day 33 from hepatic failure, whereas 6 (10-14 Gy) are alive and well 250 to 500 days after irradiation. In conclusion, fractionated TBI did not offer advantages over single-dose TBI with regard to acute toxicity and early mortality; rather, these were dependent upon the total dose of TBI. The total acutely tolerated dose was dependent upon the exposure rate; however, only dogs given fractionated TBI became healthy long-term survivors

  4. In vivo assessment of the tolerance dose of small liver volumes after single-fraction HDR irradiation

    International Nuclear Information System (INIS)

    Ricke, Jens; Seidensticker, Max; Luedemann, Lutz; Pech, Maciej; Wieners, Gero; Hengst, Susanne; Mohnike, Konrad; Cho, Chie Hee; Lopez Haenninen, Enrique; Al-Abadi, Hussain; Felix, Roland; Wust, Peter

    2005-01-01

    Purpose: To prospectively assess a dose-response relationship for small volumes of liver parenchyma after single-fraction irradiation. Methods and Materials: Twenty-five liver metastases were treated by computed tomography (CT)-guided interstitial brachytherapy. Magnetic resonance imaging was performed 1 day before and 3 days and 6, 12, and 24 weeks after therapy. MR sequences included T1-w gradient echo (GRE) enhanced by hepatocyte-targeted gadobenate dimeglumine. All MRI data sets were merged with 3D dosimetry data and evaluated by two radiologists. The reviewers indicated the border of hyperintensity on T2-w images (edema) or hypointensity on T1-w images (loss of hepatocyte function). Based on the total 3D data, a dose-volume histogram was calculated. We estimated the threshold dose for either edema or function loss as the D 90 , i.e., the dose achieved in at least 90% of the pseudolesion volume. Results: Between 3 days and 6 weeks, the extension of the edema increased significantly from the 12.9 Gy isosurface to 9.9 Gy (standard deviation [SD], 3.3 and 2.6). No significant change was detected between 6 and 12 weeks. After 24 weeks, the edematous tissue had shrunk significantly to 14.7 Gy (SD, 4.2). Three days postbrachytherapy, the D 90 for hepatocyte function loss reached the 14.9 Gy isosurface (SD, 3.9). At 6 weeks, the respective zone had increased significantly to 9.9 Gy (SD, 2.3). After 12 and 24 weeks, the dysfunction volume had decreased significantly to the 11.9 Gy and 15.2 Gy isosurface, respectively (SD, 3 and 4.1). Conclusions: The 95% interval from 7.6 to 12.2 Gy found as the minimal hepatocyte tolerance after 6 weeks accounts for the radiobiologic variations found in CT-guided brachytherapy, including heterogeneous dose rates by variable catheter arrays

  5. Internal friction in Al alloys after neutron irradiation at low temperature

    International Nuclear Information System (INIS)

    Takamura, S.; Kobiyama, M.

    1985-01-01

    Internal friction and elastic modulus of dilute Al alloys have been measured after fast neutron irradiation at about 5 K. The internal friction spectra in Al-Pb, Al-Si, Al-Zn, Al-Ag, Al-Sn and Al-In are very similar. This result suggests that the configuration of the interstitial-solute atom complex in these alloys is very similar. In Al-Mg, the main complexes have the configuration with nearly symmetry, but its internal friction spectrum is different from that of the above-mentioned alloys. The internal friction spectra and their annealing behavior in Al-Be, Al-Mn, Al-Fe and Al-Cu demonstrate that the configuration of their interstitial-solute atom complex seems to be different from each other and the main complex in these alloys is immobile until stage III. (author)

  6. Shock absorber

    International Nuclear Information System (INIS)

    Nemeth, J.D.

    1981-01-01

    A shock absorber for the support of piping and components in a nuclear power plant is described. It combines a high degree of stiffness under sudden shocks, e.g. seismic disturbances, with the ability to allow for thermal expansion without resistance when so required. (JIW)

  7. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age

    International Nuclear Information System (INIS)

    Garnier, A.

    1968-01-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [fr

  8. In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

    Directory of Open Access Journals (Sweden)

    Kropf Siegfried

    2011-09-01

    Full Text Available Abstract Background To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Materials and methods Fifty patients with 76 malignant liver tumors treated by computed tomography (CT-guided high-dose-rate brachytherapy (HDR-BT were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Results Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p p = 0.001 and p = 0.004, respectively. There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose

  9. Administration of the peroxisomal proliferator-activated receptor γ agonist pioglitazone during fractionated brain irradiation prevents radiation-induced cognitive impairment

    International Nuclear Information System (INIS)

    Zhao Weiling; Payne, Valerie; Tommasi, Ellen; Diz, Debra I.; Hsu, F.-C.; Robbins, Mike E.

    2007-01-01

    Purpose: We hypothesized that administration of the anti-inflammatory peroxisomal proliferator-activated receptor γ (PPARγ) agonist pioglitazone (Pio) to adult male rats would inhibit radiation-induced cognitive impairment. Methods and Materials: Young adult male F344 rats received one of the following: (1) fractionated whole brain irradiation (WBI); 40 or 45 Gy γ-rays in 4 or 4.5 weeks, respectively, two fractions per week and normal diet; (2) sham-irradiation and normal diet; (3) WBI plus Pio (120 ppm) before, during, and for 4 or 54 weeks postirradiation; (4) sham-irradiation plus Pio; or (5) WBI plus Pio starting 24h after completion of WBI. Results: Administration of Pio before, during, and for 4 or 54 weeks a