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Sample records for clinical rbe values

  1. Clinical investigation on RBE estimation for heavy particle radiotherapy

    International Nuclear Information System (INIS)

    Tsuji, Hiroshi; Kamada, Tadashi; Yanagi, Takeshi; Mizoe, Junetsu; Tsujii, Hirohiko

    2004-01-01

    Analysis of the clinical updated data of the prostate cancer patients treated with carbon-ions was performed for the purpose of investigating the clinical relative biological effectiveness (RBE) values of carbon ion beams. Most of the patients received the carbon ion radiotherapy (C-ion RT) with the dose of 66.0 GyE/20 fractions. Probabilities of the late urethral morbidity and biochemical tumor control with this dose fractionation were calculated using the actual updated clinical data. The linear energy transfer (LET) values and physical carbon ion doses of urethra were obtained from treatment planning data. RBE values were calculated from the ratio of average carbon physical doses and photon doses which cause the same grade of urethra reaction with the same probabilities. Obtained RBE values were compared with the values that are being used in actual carbon ion radiotherapy in National Institute of Radiological Sciences (NIRS). In addition, relative RBE of carbon ion beams for biochemical tumor control was calculated using the data from the literature. As a result, the RBE values being used for the treatment were thought to be proper enough for both the urethra reaction and tumor control. (author)

  2. RBE and clinical response in radiotherapy with neutron beams

    International Nuclear Information System (INIS)

    Ellis, F.

    1984-01-01

    Consideration of the clinical results reported, when a cyclotron produced neutron beam was used for treatments in the pelvis region, suggested that a constant RBE of 3 should not have been used for all neutron doses. Instead a variable RBE, which increased from approximately 3 to 8 (with decreasing dose), should have been used. Although some of these RBE values are much higher than 3, they have been observed in clinical practice. An ''equivalent photon'' isodose plan was produced by employing a variable RBE and, by taking a TDF limit of 86 for bowel, an isoeffect plan was produced. This shows that in the clinical situation under consideration much of the pelvis was overdosed. Doses to tumour cells and late effects are also briefly considered. It is suggested that, in neutron therapy, both an ''equivalent photon'' isodose plan and an isoeffect plan should be produced prior to treatment. (author)

  3. Towards Achieving the Full Clinical Potential of Proton Therapy by Inclusion of LET and RBE Models

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Bleddyn [Gray Laboratory, CRUK/MRC Oxford Oncology Institute, The University of Oxford, ORCRB-Roosevelt Drive, Oxford OX3 7DQ (United Kingdom)

    2015-03-17

    Despite increasing use of proton therapy (PBT), several systematic literature reviews show limited gains in clinical outcomes, with publications mostly devoted to recent technical developments. The lack of randomised control studies has also hampered progress in the acceptance of PBT by many oncologists and policy makers. There remain two important uncertainties associated with PBT, namely: (1) accuracy and reproducibility of Bragg peak position (BPP); and (2) imprecise knowledge of the relative biological effect (RBE) for different tissues and tumours, and at different doses. Incorrect BPP will change dose, linear energy transfer (LET) and RBE, with risks of reduced tumour control and enhanced toxicity. These interrelationships are discussed qualitatively with respect to the ICRU target volume definitions. The internationally accepted proton RBE of 1.1 was based on assays and dose ranges unlikely to reveal the complete range of RBE in the human body. RBE values are not known for human (or animal) brain, spine, kidney, liver, intestine, etc. A simple efficiency model for estimating proton RBE values is described, based on data of Belli et al. and other authors, which allows linear increases in α and β with LET, with a gradient estimated using a saturation model from the low LET α and β radiosensitivity parameter input values, and decreasing RBE with increasing dose. To improve outcomes, 3-D dose-LET-RBE and bio-effectiveness maps are required. Validation experiments are indicated in relevant tissues. Randomised clinical studies that test the invariant 1.1 RBE allocation against higher values in late reacting tissues, and lower tumour RBE values in the case of radiosensitive tumours, are also indicated.

  4. Towards Achieving the Full Clinical Potential of Proton Therapy by Inclusion of LET and RBE Models

    International Nuclear Information System (INIS)

    Jones, Bleddyn

    2015-01-01

    Despite increasing use of proton therapy (PBT), several systematic literature reviews show limited gains in clinical outcomes, with publications mostly devoted to recent technical developments. The lack of randomised control studies has also hampered progress in the acceptance of PBT by many oncologists and policy makers. There remain two important uncertainties associated with PBT, namely: (1) accuracy and reproducibility of Bragg peak position (BPP); and (2) imprecise knowledge of the relative biological effect (RBE) for different tissues and tumours, and at different doses. Incorrect BPP will change dose, linear energy transfer (LET) and RBE, with risks of reduced tumour control and enhanced toxicity. These interrelationships are discussed qualitatively with respect to the ICRU target volume definitions. The internationally accepted proton RBE of 1.1 was based on assays and dose ranges unlikely to reveal the complete range of RBE in the human body. RBE values are not known for human (or animal) brain, spine, kidney, liver, intestine, etc. A simple efficiency model for estimating proton RBE values is described, based on data of Belli et al. and other authors, which allows linear increases in α and β with LET, with a gradient estimated using a saturation model from the low LET α and β radiosensitivity parameter input values, and decreasing RBE with increasing dose. To improve outcomes, 3-D dose-LET-RBE and bio-effectiveness maps are required. Validation experiments are indicated in relevant tissues. Randomised clinical studies that test the invariant 1.1 RBE allocation against higher values in late reacting tissues, and lower tumour RBE values in the case of radiosensitive tumours, are also indicated

  5. Variable RBE in proton therapy: comparison of different model predictions and their influence on clinical-like scenarios

    International Nuclear Information System (INIS)

    Giovannini, Giulia; Böhlen, Till; Cabal, Gonzalo; Bauer, Julia; Tessonnier, Thomas; Frey, Kathrin; Debus, Jürgen; Mairani, Andrea; Parodi, Katia

    2016-01-01

    In proton radiation therapy a constant relative biological effectiveness (RBE) of 1.1 is usually assumed. However, biological experiments have evidenced RBE dependencies on dose level, proton linear energy transfer (LET) and tissue type. This work compares the predictions of three of the main radio-biological models proposed in the literature by Carabe-Fernandez, Wedenberg, Scholz and coworkers. Using the chosen models, a spread-out Bragg peak (SOBP) as well as two exemplary clinical cases (single field and two fields) for cranial proton irradiation, all delivered with state-of-the-art pencil-beam scanning, have been analyzed in terms of absorbed dose, dose-averaged LET (LET D ), RBE-weighted dose (D RBE ) and biological range shift distributions. In the systematic comparison of RBE predictions by the three models we could show different levels of agreement depending on (α/β) x and LET values. The SOBP study emphasizes the variation of LET D and RBE not only as a function of depth but also of lateral distance from the central beam axis. Application to clinical-like scenario shows consistent discrepancies from the values obtained for a constant RBE of 1.1, when using a variable RBE scheme for proton irradiation in tissues with low (α/β) x , regardless of the model. Biological range shifts of 0.6– 2.4 mm (for high (α/β) x ) and 3.0 – 5.4 mm (for low (α/β) x ) were found from the fall-off analysis of individual profiles of RBE-weighted fraction dose along the beam penetration depth. Although more experimental evidence is needed to validate the accuracy of the investigated models and their input parameters, their consistent trend suggests that their main RBE dependencies (dose, LET and (α/β) x ) should be included in treatment planning systems. In particular, our results suggest that simpler models based on the linear-quadratic formalism and LET D might already be sufficient to reproduce important RBE dependencies for re-evaluation of plans optimized with

  6. Review of RBE values of 15 MeV neutrons for effects on normal tissues

    NARCIS (Netherlands)

    Broerse, J.J.

    1974-01-01

    Values of the relative biological effectiveness (RBE) of fast neutrons for effect on normal tissue depend not only on the neutron energy and the dose, but also on the type of tissue irradiated. Values of the RBE of 15 MeV neutrons are reviewed for rapidly proliferating rodent tissue, such as mouse

  7. submitter Variable RBE in proton therapy: comparison of different model predictions and their influence on clinical-like scenarios

    CERN Document Server

    Giovannini, Giulia; Cabal, Gonzalo; Bauer, Julia; Tessonnier, Thomas; Frey, Kathrin; Debus, Jürgen; Mairani, Andrea; Parodi, Katia

    2016-01-01

    Background: In proton radiation therapy a constant relative biological effectiveness (RBE) of 1.1 is usually assumed. However, biological experiments have evidenced RBE dependencies on dose level, proton linear energy transfer (LET) and tissue type. This work compares the predictions of three of the main radio-biological models proposed in the literature by Carabe-Fernandez, Wedenberg, Scholz and coworkers. Methods: Using the chosen models, a spread-out Bragg peak (SOBP) as well as two exemplary clinical cases (single field and two fields) for cranial proton irradiation, all delivered with state-of-the-art pencil-beam scanning, have been analyzed in terms of absorbed dose, dose-averaged LET $(LET_D)$, RBE-weighted dose $(D_{RBE})$ and biological range shift distributions. Results: In the systematic comparison of RBE predictions by the three models we could show different levels of agreement depending on $(α/β) x$ and LET values. The SOBP study emphasizes the variation of LET D and RBE not only as a functi...

  8. submitter Data-driven RBE parameterization for helium ion beams

    CERN Document Server

    Mairani, A; Dokic, I; Valle, S M; Tessonnier, T; Galm, R; Ciocca, M; Parodi, K; Ferrari, A; Jäkel, O; Haberer, T; Pedroni, P; Böhlen, T T

    2016-01-01

    Helium ion beams are expected to be available again in the near future for clinical use. A suitable formalism to obtain relative biological effectiveness (RBE) values for treatment planning (TP) studies is needed. In this work we developed a data-driven RBE parameterization based on published in vitro experimental values. The RBE parameterization has been developed within the framework of the linear-quadratic (LQ) model as a function of the helium linear energy transfer (LET), dose and the tissue specific parameter ${{(\\alpha /\\beta )}_{\\text{ph}}}$ of the LQ model for the reference radiation. Analytic expressions are provided, derived from the collected database, describing the $\\text{RB}{{\\text{E}}_{\\alpha}}={{\\alpha}_{\\text{He}}}/{{\\alpha}_{\\text{ph}}}$ and ${{\\text{R}}_{\\beta}}={{\\beta}_{\\text{He}}}/{{\\beta}_{\\text{ph}}}$ ratios as a function of LET. Calculated RBE values at 2 Gy photon dose and at 10% survival ($\\text{RB}{{\\text{E}}_{10}}$ ) are compared with the experimental ones. Pearson's correlati...

  9. WE-FG-BRB-01: Clinical Significance of RBE Variations in Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Paganetti, H. [Massachusetts General Hospital (United States)

    2016-06-15

    The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences between particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to

  10. NIRS methods of specifying carbon ion dose verification of RBE and tumour specific radiosensitivity

    International Nuclear Information System (INIS)

    Matsufuji, Naruhiro; Kanai, Tatsuaki; Kanematsu, Nobuyuki

    2006-01-01

    Clinical dose distribution of therapeutic carbon beams, currently used at National Institute of Radiological Sciences (NIRS) Heavy Ion Medical Accelerator in Chiba (HIMAC), is designed based on in-vitro Human Salivary Gland (HSG) cell survival response and clinical experiences of fast neutron radiotherapy. At first, the biological dose distribution is designed so as to cause a flat biological effect on HSG cells in spread-out Bragg peak (SOBP) region. Then, the entire biological dose distribution is evenly raised in order to attain relative biological effectiveness (RBE)=3.0 at a depth where dose-averaged linear energy transfer (LET) is 80 keV/μm. A retrospective analysis was made to examine appropriateness on the estimation of the biological effectiveness of carbon-ion radiotherapy using resultant data of clinical trials at HIMAC. Using this RBE system, over 2,700 patients have been treated by carbon beams. As a part of these patient data, local control rate of non-small lung cancer, were analysed to verify the clinical RBE of the carbon beam. The local control rate was compared with those for published by groups of Gunma University and Massachusetts General Hospital. Using a simplified tumour control probability (TCP) model, clinical RBE values were obtained for different level of the tumour control probability. For the 50% level of the clinical TCP, the RBE values nearly coincide with those of in-vitro human salivary gland cell survival at 10%. For the higher level of the clinical TCP, the RBE values approach closer to those adapted in clinical trials at HIMAC. The approach was also applied for those of chordoma, bone and soft tissue sarcoma and rectal cancer. Difference in radiosensitivity is observed for the tumours. (author)

  11. RBE/absorbed dose relationship of d(50)-Be neutrons determined for early intestinal tolerance in mice

    International Nuclear Information System (INIS)

    Gueulette, J.; Wambersie, A.

    1978-01-01

    RBE/absorbed dose relationship of d(50)-Be neutrons (ref.: 60 Co) was determined using intestinal tolerance in mice (LD50) after single and fractionated irradiation. RBE is 1.8 for a single fraction (about 1000 rad 60 Co dose); it increases when decreasing dose and reaches the plateau value of 2.8 for a 60 Co dose of about 200 rad. This RBE value is used for the clinical applications with the cyclotron 'Cyclone' at Louvain-la-Neuve [fr

  12. In vitro RBE-LET dependence for multiple particle types

    DEFF Research Database (Denmark)

    Sørensen, Brita Singers; Overgaard, Jens; Bassler, Niels

    2011-01-01

    Background. In vitro RBE values for various high LET radiation types have been determined for many different cell types. Occasionally it is criticized that RBE for a given endpoint cannot be single-value dependent on LET alone, but also on particle species, due to the different dose deposition...... profiles on microscopic scale. Hence LET is not sufficient as a predictor of RBE, and this is one of the motivations for development of radiobiological models which explicitly depend on the detailed particle energy spectrum of the applied radiation field. The aim of the present study is to summarize...... the available data in the literature regarding the dependency of RBE on LET for different particles. Method. As RBE is highly dependent on cell type and endpoint, we discriminated the RBE-LET relationship for the three investigated cell lines and at the same endpoint (10% survival in colony formation). Data...

  13. RBE for deterministic effects

    International Nuclear Information System (INIS)

    1990-01-01

    In the present report, data on RBE values for effects in tissues of experimental animals and man are analysed to assess whether for specific tissues the present dose limits or annual limits of intake based on Q values, are adequate to prevent deterministic effects. (author)

  14. Monte Carlo simulations of the cellular S-value, lineal energy and RBE for BNCT

    International Nuclear Information System (INIS)

    Liu Chingsheng; Tung Chuanjong

    2006-01-01

    Due to the non-uniform uptake of boron-containing pharmaceuticals in cells and the short-ranged alpha and lithium particles, microdosimetry provides useful information on the cellular dose and response of boron neutron capture therapy (BNCT). Radiation dose and quality in BNCT may be expressed in terms of the cellular S-value and the lineal energy spectrum. In the present work, Monte Carlo simulations were performed to calculate these microdosimetric parameters for different source-target configurations and sizes in cells. The effective relative biological effectiveness (RBE) of the Tsing Hua Open-pool Reactor (THOR) epithermal neutron beam was evaluated using biological weighting functions that depended on the lineal energy. RBE changes with source-target configurations and sizes were analyzed. (author)

  15. Analytical probabilistic modeling of RBE-weighted dose for ion therapy

    Science.gov (United States)

    Wieser, H. P.; Hennig, P.; Wahl, N.; Bangert, M.

    2017-12-01

    Particle therapy is especially prone to uncertainties. This issue is usually addressed with uncertainty quantification and minimization techniques based on scenario sampling. For proton therapy, however, it was recently shown that it is also possible to use closed-form computations based on analytical probabilistic modeling (APM) for this purpose. APM yields unique features compared to sampling-based approaches, motivating further research in this context. This paper demonstrates the application of APM for intensity-modulated carbon ion therapy to quantify the influence of setup and range uncertainties on the RBE-weighted dose. In particular, we derive analytical forms for the nonlinear computations of the expectation value and variance of the RBE-weighted dose by propagating linearly correlated Gaussian input uncertainties through a pencil beam dose calculation algorithm. Both exact and approximation formulas are presented for the expectation value and variance of the RBE-weighted dose and are subsequently studied in-depth for a one-dimensional carbon ion spread-out Bragg peak. With V and B being the number of voxels and pencil beams, respectively, the proposed approximations induce only a marginal loss of accuracy while lowering the computational complexity from order O(V × B^2) to O(V × B) for the expectation value and from O(V × B^4) to O(V × B^2) for the variance of the RBE-weighted dose. Moreover, we evaluated the approximated calculation of the expectation value and standard deviation of the RBE-weighted dose in combination with a probabilistic effect-based optimization on three patient cases considering carbon ions as radiation modality against sampled references. The resulting global γ-pass rates (2 mm,2%) are > 99.15% for the expectation value and > 94.95% for the standard deviation of the RBE-weighted dose, respectively. We applied the derived analytical model to carbon ion treatment planning, although the concept is in general applicable to other

  16. Experimental RBE values of high LET radiations at low doses and the implications for quality factor assignment

    International Nuclear Information System (INIS)

    Sinclair, W.K.

    1985-01-01

    RBE determinations of special relevance to the quality factor assigned for radiation protection purposes are those relating to the effects of special importance at low doses, namely carcinogenesis and mutagenesis. Measurements of RBE that enable the maximum value of RBE, namely RBEsub(M), to be determined at low doses require data points as low as 0.1 Gy or even 0.01 Gy or high LET radiation. Corresponding data points as low as 0.5 Gy to 0.25 Gy or less of low LET radiation are also needed. Relatively few such measurements have been made, but many more are available now than formerly. A review of recent RBEs for tumour induction, life shortening, transformation, cytogenetics and genetic endpoints, which updated an earlier review, indicates a broad range of results. The principle findings are that X rays are more effective than hard γ rays at low doses by a factor of about 2, and that fission neutrons, alpha particles and heavy ions may be 30-50 times more effective, on the average, (some endpoints give higher, some lower values) than hard γ rays. The data would seem to indicate that in order to provide approximately equal protection against the risks at low doses from all radiations, adjustments upward in the quality factors for high LET radiations need to be considered. (author)

  17. RBE-LET relationships of high-LET radiations in drosophila mutations

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Takatsuji, Toshihiro; Nagano, Masaaki; Takada, Jun; Endo, Satoru; Hoshi, Masaharu

    1999-01-01

    The relative biological effectiveness (RBE) of 252 Cf neutrons and synchrotron-generated high-energy charged particles for mutation induction was evaluated as a function of linear energy transfer (LET), using the loss of heterozygosity for wing-hair mutations and the reversion of the mutant white-ivory eye-color in Drosophila melanogaster. Loss of heterozygosity for wing-hair mutations results predominantly from mitotic crossing over induced in wing anlage cells of larvae, while the reverse mutation of eye-color is due to an intragenic structural change (2.96 kb-DNA excision) in the white locus on the X-chromosome. The measurements were performed in a combined mutation assay system so that induced mutant wing-hair clones as well as revertant eye-color clone can be detected simultaneously in the same individual. Larvae were irradiated at the age of 3 days post oviposition with 252 Cf neutrons, carbon beam or neon beam. For the neutron irradiation, the RBE values for wing-hair mutations were larger than that for eye-color mutation by about 7 fold. The RBE of carbon ions for producing the wing-hair mutations increased with increase in LET. The estimated RBE values were found to be in the range 2 to 6.5 for the wing-hair. For neon beam irradiation, the RBE values for wing-hair mutations peak near 150 keV/μm and decrease with further increase in LET. On the other hand, the RBE values for the induction of the eye-color mutation are nearly unity in 252 Cf neutrons and both ions throughout the LET range irradiated. We discuss the relationships between the initial DNA damage and LET in considering the mechanism of somatic mutation induction. (author)

  18. The relative biological effectiveness (RBE) of high-energy electrons, x-rays and Co-60 gamma-rays

    International Nuclear Information System (INIS)

    Kiyono, Kunihiro

    1974-01-01

    Linac (Mitsubishi-Shimizu 15 MeV medical linear accelerator) electron beams with actual generated energies of 8, 10, 12 and 15 MeV were compared with X-ray beams having energies of 8 and 10 MV. The RBE values were calculated from 50 percent hatch-ability (LD 50 ) in silk-worm embryos, 30-days lethality (LDsub(50/30)) in ddY mice, and mean lethal dose (Do) in cultured mouse YL cells or human FL cells. To estimate the RBE in clinical experiments, LRD (leukocyte reduction dose) value was calculated for each patient irradiated on the chest or lumbar vertebrae. It was concluded that there is little difference in practical significance between 8 to 10 MV X-rays and 8 to 15 MeV electrons, and that the biological effects of Linac radiations are about 90 to 100 percent of the effect of 60 Co gamma rays. The RBE values gradually decreased, contrary to the elevation of energy between 8 and 15 MeV for electrons and between 8 and 10 MV for X-rays. These values were compared with those of earlier reviews of work in this field, and were briefly discussed. (Evans, J.)

  19. The RBE of Fractionated Fast Neutron on Walker 256 Carcinosarcoma with KCCH-Cyclotron

    International Nuclear Information System (INIS)

    Yoo, Seong Yul; Koh, Kyoung Hwan; Cho, Chul Koo; Park, Charn Il; Kang, Wee Saing

    1987-01-01

    For evaluation of biological effect of p+(50.5 MeV) Be neutron beam produced by Korea Cancer Center Hospital(KCCH) cyclotron the RBE had been measured in experimental tumor Walker 256 carcinosarcoma as well as normal tissue, mouse intestine and bone marrow, in single and fractionated irradiation. As pilot study, the RBE had been measured for the mouse jejunal crypt cells in single whole body irradiation of which the result was 2.8. The obtained RBE values of TCD 50 of Walker 256 tumor, bone marrow and intestine in single irradiation were 1.9, 1.9 and 1.5 respectively. In fractionated irradiation, the RBE value of tumor Walker 256 was decreased as increasing of fraction number and increased as increasing of fraction size

  20. Changes in RBE of 14-MeV (d+T) neutrons for V79 cells irradiated in air and in a phantom: Is RBE enhanced near the surface?

    International Nuclear Information System (INIS)

    Schalla, S.; Herskind, C.; Hoever, K.H.; Lorenz, W.J.; Hahn, E.W.

    1998-01-01

    The relative biological effectiveness (RBE) for inactivation of V79 cells was determined as function of dose at the Heidelberg 14-MeV (d+T) neutron therapy facility after irradiation with single doses in air and at different depths in a therapy phantom. Furthermore, to assess the reproducibility of RBE determinations in different experiments we examined the relationship between the interexperimental variation in radiosensitivity towards neutrons with that towards low LET 60 Co photons. Clonogenic survival of V79 cells was determined using the colony formation assay. The cells were irradiated in suspension in small volumes (1.2 ml) free in air or at defined positions in the perspex phantom. Neutron doses were in the range, D t =0.5-4 Gy. 60 Co photons were used as reference radiation. The radiosensitivity towards neutrons varied considerably less between individual experiments than that towards photons and also less than RBE. However, the mean sensitivity of different series was relatively constant. RBE increased with decreasing dose per fraction from RBE=2.3 at 4 Gy to RBE=3.1 at 0.5 Gy. No significant difference increased with decreasing dose per fraction from RBE=2.3 at 4 Gy to RBE=3.1 at 0.5 Gy. No significant difference in RBE could be detected between irradiation at 1.6 cm and 9.4 cm depth in the phantom. However, an approximately 20% higher RBE was found for irradiation free in air compared with inside the phantom. Combining the two effects, irradiation with 0.5 Gy free in air yielded an approximately 40% higher RBE than a dose of 2 Gy inside the phantom. The measured values of RBE as function of dose per fraction within the phantom is consistent with the energy of the neutron beam. The increased RBE free in air, however, is greater than expected from microdosimetric parameters of the beam. (orig./MG) [de

  1. Biological effects of tritium and its behavior in the body. Ratio of biological effects (RBE)

    International Nuclear Information System (INIS)

    Takeda, Hiroshi

    1997-01-01

    Biological effects of radiation is known to depend not only on the radiation energy absorbed in the cells and the tissues of an organism, but also on ionization density. RBE, a biological effects ratio is used to correct the difference in absorbed dose due to the kind of nuclide. Determination of RBE has been carried out with end points of various biological effects as indicators for characterization of tritium effects. Recently, the tritium RBE was estimated from the indicators such as carcinogenesis, gene abnormalities, teratogenesis and gonadal abnormalities. The RBE values for HTO and 3 H-thymidine were in the range of 0.7-4.5 and 0.9-5.9. The varieties in RBE values were thought to be caused by the differences in the species or cell lines used, those in end points such as cell death, induction of mutagenesis and those in the kind of radiation as the control as well as the dose rate. Thus, there were various factors mediating RBE. (M.N.)

  2. Relative Biologic Effectiveness (RBE) of 50 kV X-rays Measured in a Phantom for Intraoperative Tumor-Bed Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi; Schneider, Frank; Ma, Lin; Wenz, Frederik [Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim (Germany); Herskind, Carsten, E-mail: carsten.herskind@medma.uni-heidelberg.de [Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim (Germany)

    2013-03-15

    Purpose: Intraoperative radiation therapy (IORT) with low-energy x-rays is used to treat the tumor bed during breast-conserving surgery. The purpose was to determine the relative biologic effectiveness (RBE) of 50-kV x-rays for inactivation of cells irradiated in a tumor-bed phantom. Methods and Materials: The RBE was determined for clonogenic inactivation of human tumor and normal cells (MCF7, human umbilical vein endothelial cells, normal skin fibroblasts), and hamster V79 cells. The 50-kV x-rays from the Intrabeam machine (Carl Zeiss Surgical) with a spherical 4-cm applicator were used. Cells were irradiated in a water-equivalent phantom at defined distances (8.1-22.9 mm) from the applicator surface. The 50-kV x-rays from a surface therapy machine (Dermopan, Siemens) were included for comparison; 6-MV x-rays were used as reference radiation. Results: At 8.1-mm depth in the phantom (dose rate 15.1 Gy/h), mean RBE values of 50-kV x-rays from Intrabeam were 1.26 to 1.42 for the 4 cell types at doses yielding surviving fractions in the range of 0.01 to 0.5. Confidence intervals were in the range of 1.2 and 1.5. Similar RBE values were found for 50-kV x-rays from Dermopan for V79 (1.30, CI 1.25-1.36, P=.74) and GS4 (1.42, CI 1.30-1.54, P=.67). No significant dependence of RBE on dose was found for Intrabeam, but RBE decreased at a larger distance (12.7 mm; 9.8 Gy/h). Conclusions: An increased clinically relevant RBE was found for cell irradiation with Intrabeam at depths in the tumor bed targeted by IORT. The reduced RBE values at larger distances may be related to increased repair of sublethal damage during protracted irradiation or to hardening of the photon beam energy.

  3. ES-RBE Event sequence reliability Benchmark exercise

    International Nuclear Information System (INIS)

    Poucet, A.E.J.

    1991-01-01

    The event Sequence Reliability Benchmark Exercise (ES-RBE) can be considered as a logical extension of the other three Reliability Benchmark Exercices : the RBE on Systems Analysis, the RBE on Common Cause Failures and the RBE on Human Factors. The latter, constituting Activity No. 1, was concluded by the end of 1987. The ES-RBE covered the techniques that are currently used for analysing and quantifying sequences of events starting from an initiating event to various plant damage states, including analysis of various system failures and/or successes, human intervention failure and/or success and dependencies between systems. By this way, one of the scopes of the ES-RBE was to integrate the experiences gained in the previous exercises

  4. SU-F-T-666: Molecular-Targeted Gold Nanorods Enhances the RBE of Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khoo, A; Sahoo, N; Krishnan, S; Diagaradjane, P [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: In recent years, proton beam radiation therapy (PBRT) has gained significant attention in the treatment of tumors in anatomically complex locations. However, the therapeutic benefit of PBRT is limited by a relative biological effectiveness (RBE) of just 1.1. The purpose of this study is to evaluate whether this limitation can be overcome by artificially enhancing the RBE using molecular-targeted gold nanorods (GNRs). Methods: Molecular-targeting of GNRs was accomplished using Cetuximab (antibody specific to epidermal growth factor receptor that is over-expressed in tumors) conjugated GNRs (cGNRs) and their binding affinity to Head and Neck cancer cells was confirmed using dark field microscopy and Transmission Electron Microscopy (TEM). The radiosensitization potential of cGNRs when irradiated with photon (6MV) and proton (100 and 160 MeV) beams was determined using clonogenic assays. The RBE at 10% surviving fraction (RBE{sub 10}) for proton therapies at central and distal locations of SOBP was calculated with respect to 6 MV photons. IgGconjugated GNRs (iGNRs) were used as controls in all experiments. Results: cGNRs demonstrated significant radiosensitization when compared to iGNRs for 6MV photons (1.14 vs 1.04), 100 MeV protons (1.19 vs 1.04), and 160 MeV protons (1.17 vs 1.04). While RBE10 for proton beams at the center of SOBP revealed similar effects for both 100 and 160 MeV (RBE{sup 10}=1.39 vs 1.38; p>0.05), enhanced radiosensitization was observed at the distal SOBP with 100 MeV beams demonstrating greater effect than 160 MeV beams (RBE{sup 10}=1.79 vs 1.6; p<0.05). Conclusion: EGFR-targeting GNRs significantly enhance the RBE of protons well above the accepted 1.1 value. The enhanced RBE observed for lower energy protons (100 MeV) and at the distal SOBP suggests that low energy components may play a role in the observed radiosensitization effect. This strategy holds promise for clinical translation and could evolve as a paradigm-changing approach

  5. RBE of thermal neutrons for induction of chromosome aberrations in human lymphocytes.

    Science.gov (United States)

    Schmid, E; Wagner, F M; Canella, L; Romm, H; Schmid, T E

    2013-03-01

    The induction of chromosome aberrations in human lymphocytes irradiated in vitro with slow neutrons was examined to assess the maximum low-dose RBE (RBE(M)) relative to (60)Co γ-rays. For the blood irradiations, cold neutron beam available at the prompt gamma activation analysis facility at the Munich research reactor FRM II was used. The given flux of cold neutrons can be converted into a thermally equivalent one. Since blood was taken from the same donor whose blood had been used for previous irradiation experiments using widely varying neutron energies, the greatest possible accuracy was available for such an estimation of the RBE(M) avoiding the inter-individual variations or differences in methodology usually associated with inter-laboratory comparisons. The magnitude of the coefficient α of the linear dose-response relationship (α = 0.400 ± 0.018 Gy(-1)) and the derived RBE(M) of 36.4 ± 13.3 obtained for the production of dicentrics by thermal neutrons confirm our earlier observations of a strong decrease in α and RBE(M) with decreasing neutron energy lower than 0.385 MeV (RBE(M) = 94.4 ± 38.9). The magnitude of the presently estimated RBE(M) of thermal neutrons is-with some restrictions-not significantly different to previously reported RBE(M) values of two laboratories.

  6. Neutron RBE for normal tissues

    International Nuclear Information System (INIS)

    Field, S.B.; Hornsey, S.

    1979-01-01

    RBE for various normal tissues is considered as a function of neutron dose per fraction. Results from a variety of centres are reviewed. It is shown that RBE is dependent on neutron energy and is tissue dependent, but is not specially high for the more critical tissues or for damage occurring late after irradiation. (author)

  7. submitter Dose prescription in carbon ion radiotherapy: How to compare two different RBE-weighted dose calculation systems

    CERN Document Server

    Molinelli, Silvia; Mairani, Andrea; Matsufuji, Naruhiro; Kanematsu, Nobuyuki; Inaniwa, Taku; Mirandola, Alfredo; Russo, Stefania; Mastella, Edoardo; Hasegawa, Azusa; Tsuji, Hiroshi; Yamada, Shigeru; Vischioni, Barbara; Vitolo, Viviana; Ferrari, Alfredo; Ciocca, Mario; Kamada, Tadashi; Tsujii, Hirohiko; Orecchia, Roberto; Fossati, Piero

    2016-01-01

    Background and purpose: In carbon ion radiotherapy (CIRT), the use of different relative biological effectiveness (RBE) models in the RBE-weighted dose $(D_{RBE})$ calculation can lead to deviations in the physical dose $(D_{phy})$ delivered to the patient. Our aim is to reduce target $D_{phy}$ deviations by converting prescription dose values. Material and methods: Planning data of patients treated at the National Institute of Radiological Sciences (NIRS) were collected, with prescribed doses per fraction ranging from 3.6 Gy (RBE) to 4.6 Gy (RBE), according to the Japanese semi-empirical model. The $D_{phy}$ was Monte Carlo (MC) re-calculated simulating the NIRS beamline. The local effect model (LEM)_I was then applied to estimate $D_{RBE}$. Target median $D_{RBE}$ ratios between MC + LEM_I and NIRS plans determined correction factors for the conversion of prescription doses. Plans were re-optimized in a LEM_I-based commercial system, prescribing the NIRS uncorrected and corrected $D_{RBE}$. Results: The MC ...

  8. WE-FG-BRB-02: Spatial Mapping of the RBE of Scanned Particle Beams

    Energy Technology Data Exchange (ETDEWEB)

    Grosshans, D. [The University of Texas MD Anderson Cancer Center (United States)

    2016-06-15

    The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences between particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to

  9. Incidence of CNS Injury for a Cohort of 111 Patients Treated With Proton Therapy for Medulloblastoma: LET and RBE Associations for Areas of Injury

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, Drosoula; Sethi, Roshan V. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Yeap, Beow Y. [Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts (United States); Eaton, Bree R. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Ebb, David H. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Caruso, Paul A.; Rapalino, Otto [Department of Radiology (O.R.) at the Massachusetts General Hospital, Boston, Massachusetts (United States); Chen, Yen-Lin E.; Adams, Judith A.; Yock, Torunn I.; Tarbell, Nancy J.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); MacDonald, Shannon M., E-mail: smacdonald@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-05-01

    Background: Central nervous system (CNS) injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. Methods and Materials: We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. Results: At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values (P=.12). Conclusions: Central nervous system and brainstem injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between injury and LET.

  10. Incidence of CNS Injury for a Cohort of 111 Patients Treated With Proton Therapy for Medulloblastoma: LET and RBE Associations for Areas of Injury

    International Nuclear Information System (INIS)

    Giantsoudi, Drosoula; Sethi, Roshan V.; Yeap, Beow Y.; Eaton, Bree R.; Ebb, David H.; Caruso, Paul A.; Rapalino, Otto; Chen, Yen-Lin E.; Adams, Judith A.; Yock, Torunn I.; Tarbell, Nancy J.; Paganetti, Harald; MacDonald, Shannon M.

    2016-01-01

    Background: Central nervous system (CNS) injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. Methods and Materials: We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. Results: At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values (P=.12). Conclusions: Central nervous system and brainstem injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between injury and LET.

  11. Incidence of CNS Injury for a Cohort of 111 Patients Treated With Proton Therapy for Medulloblastoma: LET and RBE Associations for Areas of Injury.

    Science.gov (United States)

    Giantsoudi, Drosoula; Sethi, Roshan V; Yeap, Beow Y; Eaton, Bree R; Ebb, David H; Caruso, Paul A; Rapalino, Otto; Chen, Yen-Lin E; Adams, Judith A; Yock, Torunn I; Tarbell, Nancy J; Paganetti, Harald; MacDonald, Shannon M

    2016-05-01

    Central nervous system (CNS) injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values (P=.12). Central nervous system and brainstem injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between injury and LET. Published by Elsevier Inc.

  12. RBE of neutrons for induction of cell reproductive death and chromosome aberrations in three cell lines

    International Nuclear Information System (INIS)

    Zoetelief, J.; Kuijpers, W.C.; Baten-Wittwer, A.; Barendsen, G.W.

    1983-01-01

    The authors have compared the RBE values for induction of dicentrics and centric rings with those for cell inactivation and with the mean or effective quality factors (Q) recommended for radiation protection. The induction of cell reproductive death and chromosome aberrations has been investigated in plateau phase cultures of established lines of a rat rhabdomyosarcoma, a rat ureter carcinoma and Chinese hamster cells for single doses of 300 kV X-rays and 0.5, 4.2 and 15 MeV neutrons. The different cell lines show considerable variations in sensitivity and the RBE values obtained are presented in tabular form. The mean RBE values for the rat rhabdomyosarcoma cells are lower than those for the other two relatively resistant cell lines. Those for the Chinese hamster cells extrapolated to levels according to low doses of X-rays are in good agreement with the quoted Q values. (Auth./C.F.)

  13. SU-F-T-132: Variable RBE Models Predict Possible Underestimation of Vaginal Dose for Anal Cancer Patients Treated Using Single-Field Proton Treatments

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, A; Underwood, T; Wo, J; Paganetti, H [Massachusetts General Hospital & Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Anal cancer patients treated using a posterior proton beam may be at risk of vaginal wall injury due to the increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the beam distal edge. We investigate the vaginal dose received. Methods: Five patients treated for anal cancer with proton pencil beam scanning were considered, all treated to a prescription dose of 54 Gy(RBE) over 28–30 fractions. Dose and LET distributions were calculated using the Monte Carlo simulation toolkit TOPAS. In addition to the standard assumption of a fixed RBE of 1.1, variable RBE was considered via the application of published models. Dose volume histograms (DVHs) were extracted for the planning treatment volume (PTV) and vagina, the latter being used to calculate the vaginal normal tissue complication probability (NTCP). Results: Compared to the assumption of a fixed RBE of 1.1, the variable RBE model predicts a dose increase of approximately 3.3 ± 1.7 Gy at the end of beam range. NTCP parameters for the vagina are incomplete in the current literature, however, inferring value ranges from the existing data we use D{sub 50} = 50 Gy and LKB model parameters a=1–2 and m=0.2–0.4. We estimate the NTCP for the vagina to be 37–48% and 42–47% for the fixed and variable RBE cases, respectively. Additionally, a difference in the dose distribution was observed between the analytical calculation and Monte Carlo methods. We find that the target dose is overestimated on average by approximately 1–2%. Conclusion: For patients treated with posterior beams, the vaginal wall may coincide with the distal end of the proton beam and may receive a substantial increase in dose if variable RBE models are applied compared to using the current clinical standard of RBE equal to 1.1. This could potentially lead to underestimating toxicities when treating with protons.

  14. RBE of tritium for induction of myeloid leukemia in CBA/H mice

    International Nuclear Information System (INIS)

    Myers, D.K.; Jackson, J.S.; Gragtmans, N.J.; Jones, A.R.; Dunford, D.W.; Wyatt, H.M.; Percy, D.H.

    1990-05-01

    In order to help resolve uncertainties as to the most appropriate quality factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 grays both for tritiated water and X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative animal-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 ± 0.5 to 1.3 ± 0.3. A best estimate of the RBE for this experiment was about 1.2 ± 0.3. A Q value of 1 would thus appear to be more appropriate than a Q of 2 for tritium beta rays

  15. RBE of Cf-252 neutrons as determined by its lethal, mutagenic, and cytogenetic effects on human cells

    International Nuclear Information System (INIS)

    Ban, Sadayuki

    1989-01-01

    To assess the biological effects of neutrons, a man-made spontaneously fissioning isotope, Cf-252, is useful as an experimental model to obtain basic biological data on mixed radiation of gamma-rays and neutrons. The paper describes the lethal effect of Cf-252 radiation on human skin fibroblasts, its lethal and mutagenic effect on HeLa MR cells, and the micronuclei inducing effect on human peripheral lymphocytes. Dose-survival responses of three fibroblast cell strains exposed to Cf-252 radiation are measured. Individual difference is larger than the experimental fluctuation. D 10 values of each strain are obtained from the linear model and linear-quadratic model. Though the dose rate of X-ray is higher than that of Cf-252 radiations, the mean value of RBE(n+γ) is simply obtained as 1.86+0.31 (RBE:relative biological effectiveness). RBE(n) of Cf-252 neutrons to high-dose-rate X-rays is 2.29. After X-ray irradiation, the survival curve of HeLa MR cells gives an extrapolation number of 3.6. It is 1.3 after Cf-252 irradiation. At 50% survival, RBE(n+γ) and RBE(n) are 2.05 and 2.6, respectively. At 10% survival they are 2.05 and 2.6. The mutation frequencies after X-ray irradiation showed a significant non-linear increase with dose. Those after Cf-252 irradiation increase linearly with dose. (N.K.)

  16. CCF-RBE common cause failure reliability benchmark exercise

    International Nuclear Information System (INIS)

    Poucet, A.; Amendola, A.; Cacciabue, P.C.

    1987-01-01

    This report summarizes results, obtained by the participants in the Reliability Benchmark Exercise on Common Cause Failures (CCF-RBE). The reference power plant of the CCF-RBE was the NPP at Grohnde (KWG): it is a 1300 MW PWR plant of KWU design and operated by the utility Preussen Elektra. The systems studied were the Start-up and Shut-down system (RR/RL) and the Emergency Feedwater System (RS) both systems that can feed water into the steam generators in the emergency power mode. The CCF-RBE was organized in two phases: 1. The first phase: during which all participants have performed an analysis on the complete system as defined by the assumed boundaries, i.e. the Start-up and Shut-down system (RR/RL) and the Emergency Feedwater System (RS). 2. The second phase: in which the scope was limited to the RS system. This limitation in scope was agreed upon in the discussion on the results of the first phase, which showed that, within the boundaries of the exercise, RR/RL and RS systems could be considered independent of each other. This report gives an overview of the works carried out, the results obtained and the conclusions and lessons that could be drawn from the CCF-RBE

  17. Aspects of OER and RBE relevant to neutron therapy

    International Nuclear Information System (INIS)

    Field, S.B.; Hornsey, S.

    1979-01-01

    This chapter contains information concerning the mechanisms involved in neutron radiotherapy. Early studies on the attempts of using neutrons in radiotherapy are described. The rationale for fast neutron therapy is discussed as well as the relationships between OER and LET. Tissue responses include: repopulation of surviving cells; repair of sublethal damage; and slow repair. These mechanisms are considered separately. The relationships between RBE and dose per fraction for damage to skin, intestine, esophagus, lungs, hemopoietic tissue, and nerve tissue are discussed. Factors governing the effects of fractionation of dose in neutron radiotherapy are presented. Observations on mammalian cells and tissues show a general reduction in RBE with increasing neutron energy. The benefits of using mixed treatments, part with neutrons and the remainder with photons, are discussed. Problems with this approach include uncertainties of how the combination will effect normal tissue, how it effects slow repair, or its potentially lethal damage. Tumor response, as compared with x rays, to single and multiple doses of radiation is described. Clinical results are given

  18. WE-FG-BRB-00: The Challenges of Predicting RBE Effects in Particle Therapy and Opportunities for Improving Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences between particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to

  19. RBE for late spinal cord injury following multiple fractions of neutrons

    International Nuclear Information System (INIS)

    Geraci, J.P.; Jackson, K.L.; Christensen, G.M.; Thrower, P.D.; Mariano, M.

    1978-01-01

    Using the length of the time interval between the irradiation of lumbosacral spinal cord of mice with ten fractions of either x rays or neutrons, and the onset of hindquarter paralysis, a fast neutron RBE of 3.5 for spinal cord damage at a neutron dose per fraction of 100 rad has been measured. This RBE for spinal cord injury is significant because it is larger than the RBE being used to calculate treatment doses in neutron radiotherapy

  20. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Calugaru, V.

    2011-01-01

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60 Co gamma-rays throughout the Spread Out Bragg Peak (SOBP). We have studied the variation of the RBE at three positions in the SOBP of the 76 and 201 MeV proton beams used for cancer treatment at the Institut Curie Proton Therapy in Orsay (ICPO) in two human tumor cell lines using clonogenic cell death and the incidence of DNA double-strand breaks (DSB) as measured by pulse-field gel electrophoresis without and with endonuclease treatment to reveal clustered lesions as endpoints.The RBE for induced cell killing by the 76 MeV beam increased with depth in the SOBP. However for the 201 MeV protons it was close to that for 137 Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137 Cs g-rays, but did not depend on the proton energy or the position in the SOBP. In the second part of our work, we have shown using cell clones made deficient for known repair genes by stable or transient shRNA transfection, that the D-NHEJ pathway determine the response to protons. The response of DNA damages created in the distal part of the 76 MeV SOBP suggests that those damages belong to the class of DNA 'complex lesions' (LMDS). It also appears that the particle fluence is a major determinant of the outcome of treatment in the distal part of the SOBP. (author)

  1. Feasibility study of an experiment to measure the RBE of tritium for the induction of myeloid leukemia in animals

    International Nuclear Information System (INIS)

    Gragtmans, N.J.; Johnson, J.R.; Myers, D.K.

    1986-02-01

    A variety of RBE values ranging from about 1 to 3 for tritium have been measured by different investigators. The reason for this range in RBE can be attributed to differences in the biological endpoints measured, the reference radiation to which the effects of tritium were compared, and the tritium dosimetry of the particular study. Since the principal risk of low-level irradiation is the induction of cancers, it would be desirable to utilize this endpoint in tritium RBE experiments if these experiments are to be used to evaluate the quality factor for tritium. Furthermore, it would be desirable to use 200 kVp X-rays as the reference radiation since this radiation was suggested by ICRP as the standard reference to be used in the calculation of dose equivalents for purposes of radiation protection. Acute myeloid leukemia is one of the earliest recognized examples of radiogenic cancer in humans and this endpoint has also been the subject of animal studies. This report gives the results of a review of these animal studies to see if this endpoint is suitable for an experiment to measure the tritium RBE relative to 200 kVp X-rays. It was concluded that the male CBA/H mouse, would be a suitable species and an experiment involving 5000 animals in a four to five year study would be required to provide a useful estimate of the RBE for tritium. 72 refs

  2. Clinical application of fast neutrons

    International Nuclear Information System (INIS)

    Battermann, J.J.

    1981-01-01

    The results of treatments and clinical experiments with neutrons (from a medical d+T neutron generator with an output of 10 12 neutrons per second) are reported and discussed. Data on RBE values are presented after single doses and multiple fractions of neutrons and 60 Co-gamma rays on pulmonary metastases. The results of pilot studies on head and neck tumours, brain tumours and pelvic tumours are discussed. The accuracy of the calculated dose is tested with some in-vivo experiments during neutron irradiation of the pelvis. Estimations of RBE values for tumour control, skin damage and intestinal damage after fractionated neutron therapy are dealt with and the results obtained in treatment of sarcomas are discussed. The preliminary results are given of some clinical trials in Amsterdam. Also some data from other centres are reviewed. From these data some remarks about the future of neutron therapy are made. (Auth.)

  3. RBE of 0,85 MeV neutrons in guinea pigs with intestinal form of radiation sickness

    International Nuclear Information System (INIS)

    Shaporov, V.N.; Sokolova, T.I.; Nasonova, T.A.; Aleshin, S.N.

    1989-01-01

    Relative biological effectiveness (RBE) coefficient of 0.85 MeV neutrons was 1.87 in comparison with 0.66 MeV γ-radiation ( 137 Cs) when estimated by the death rate of guinea pigs with intestinal form of radiation sickness. LD 50/5 was 5.9 and 11.06 respectively. Features of the mortality rate dynamics, clinical picture and pathoanatomical changes are discussed

  4. Major compound-dependent variations of 10B(nα)7 Li RBE for the 9L RAT gliosarcoma in vitro and in vivo

    International Nuclear Information System (INIS)

    Coderre, J.A.; Makar, M.S.; Micca, P.L.; Nawrocky, M.M.; Joel, D.D.; Slatkin, D.N.

    1991-01-01

    Relative biological effectiveness (RBE) values for the high linear-energy-transfer (LET) radiations produced during born neutron capture therapy (BNCT) were determined using the 9L rat gliosarcorna both in vitro and as an intracerebral tumor. In the absence of 10 B, the combined effect of the recoiling protons from the 14 N(n,p) 14 C and the 1 H(n,n')p reactions, compared to an iso-effect endpoint produced by 250 kVp x-rays, yielded RBEs for these high-LET protons of 4.4 in vitro and 3.8 in an in vivo/in vitro assay. RBEs for the 10 B(n,α) 7 Li reaction were calculated from cell survival data following reactor irradiation in the presence or in the absence of the either of the amino acid, p-boronophenylalanine (BPA) or the sulfhydryl dodecaborane dimer (BSSB). With BPA, RBE values ranged from 3.5 to 11.4, while under the same set of conditions with BSSB, RBE values ranged from 1.1 to 4.3. In vitro, higher RBEs for the 10 B(n,α) 7 Li reaction using BPA than with BSSB suggest a difference in distribution of 10 B relative to the nucleus

  5. Theory of RBE. Progress report, January 1, 1977--December 1977

    International Nuclear Information System (INIS)

    Katz, R.

    1977-09-01

    Emulsion-processing combinations have been found which match the response of mammalian cells to x-rays. The grain size of these emulsions is in the implied range of sensitive element sizes in biological cells. The fading of the latent image may parallel biological repair. In consequence studies are under way of the variation in emulsion response to low LET radiations of different quality, of ''Elkind repair'', and of dose fractionation. Predictions of OER and RBE of mammalian cells to high LET radiations, from track structure theory, have been verified, once again, in Bevalac experiments. Experiment has now shown that high temperature traps in LiF respond favorably to neutrons, while low temperature traps respond favorably to gamma-rays. This result is consistent with our identification of supralinear high temperature traps as from an unidentified 2-hit trap structure. In collaboration with Oak Ridge colleagues, Monte-Carlo studies of the electron slowing down spectra of source electrons from 1 keV to 1 MeV in liquid water are being integrated into the theory of RBE. The yield of several different ions is nearly independent of the initial energy of source electrons. The results raise questions as to the physical basis for biological observations of RBE differences for x- and gamma-rays

  6. Ensemble of cell survival experiments after ion irradiation for validation of RBE models

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Thomas; Scholz, Uwe; Scholz, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Durante, Marco [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Institut fuer Festkoerperphysik, TU Darmstadt, Darmstadt (Germany)

    2012-07-01

    There is persistent interest in understanding the systematics of the relative biological effectiveness (RBE). Models such as the Local Effect Model (LEM) or the Microdosimetric Kinetic Model have the goal to predict the RBE. For the validation of these models a collection of many in-vitro cell survival experiments is most appropriate. The set-up of an ensemble of in-vitro cell survival data comprising about 850 survival experiments after both ion and photon irradiation is reported. The survival curves have been taken out from publications. The experiments encompass survival curves obtained in different labs, using different ion species from protons to uranium, varying irradiation modalities (shaped or monoenergetic beam), various energies and linear energy transfers, and a whole variety of cell types (human or rodent; normal, mutagenic or tumor; radioresistant or -sensitive). Each cell survival curve has been parameterized by the linear-quadratic model. The photon parameters have been added to the data base to allow to calculate the experimental RBE to any survival level. We report on experimental trends found within the data ensemble. The data will serve as a testing ground for RBE models such as the LEM. Finally, a roadmap for further validation and first model results using the data base in combination with the LEM are presented.

  7. RBE of 0.85 MeV neutrons in Guinea pigs with a cerebral form of radiation sickness

    International Nuclear Information System (INIS)

    Shaporov, V.N.; Sokolova, T.I.; Nasonova, T.A.; Aleshin, S.I.

    1989-01-01

    The RBE coefficient of neutrons (0.85 MeV) was 1.87 in comparison with that of electron radiation (8 MeV) as determined by the death rate of guinea pigs with the cerebral form of radiation sickness. LD 50/1.5 amounted to 43.2 and 80.7 Gy. The dynamics of clinical symptoms at the height of the disease is discussed

  8. Theory of RBE. Progress report, 1 January 1976--31 December 1976

    International Nuclear Information System (INIS)

    Katz, R.

    1976-09-01

    Experimental studies of emulsion-processing combinations have demonstrated that a range of hittedness, from 1 to 8-or-more, can be achieved with specially processed nuclear research emulsions of the Ilford K series, encompassing the range of supralinear response displayed by biological cells. In analogy with the response of biological cells to high LET radiations, the processes of ion-kill and gamma-kill have been displayed for these emulsions, in that x-rays blacken emulsion in circumstances that single alpha-particles, or even single fission fragments, leave no visible track. Track structure theory and the theory of RBE have been extended to these multi-hit detectors. Supralinearity in thermoluminescent dosimeters has been tentatively identified as due to a population of 2-or-more hit trapping sites, coexisting with the linear 1-or-more hit sites. Inferences from this identification that the response to high-LET radiations is linear and that 2-hit sites must display an RBE greater than 1 are consistent with some experimental observations. This is a second solid state detector having the capacity to mimic the response of biological systems identified from the theory of RBE

  9. Theory of RBE. Progress report, 1 January 1975--31 December 1975

    International Nuclear Information System (INIS)

    Katz, R.

    1975-09-01

    Calculations from the theory of RBE have been so simplified that RBE, D/sub x/, and oxygen enhancement ratio for a mixed radiation environment (say, pions, neutrons, and gamma-rays) can be calculated with an HP-65 pocket programmable calculator, once equivalent track segment bombardments have been found for the components of the mix, from theory or from experiment. With a least-squares seeking computer program, cellular radiosensitivity parameters have been evaluated (with 95 percent confidence limits) for many biological cells for which survival data is available at different LET's. Typically there is good agreement with visually fitted parameters, with confidence limits ranging from a few percent on up, depending on the quantity and quality of the data. The procedure reveals internal inconsistencies in the data, and may be used as the basis for the design of efficient experiments. Studies of many-hit nuclear emulsions have been initiated. These emulsions will exhibit RBE-LET properties similar to those of biological cells and tissues, and will be useful as a model system in studies of low-dose and dose-rate effects in radiobiology. A first quantitative result is that Ilford K-1 emulsion is an 8 +- 1 or-more hit detector. (auth)

  10. Relative biological effectiveness (RBE) of alpha radiation in cultured porcine aortic endothelial cells.

    Science.gov (United States)

    Thomas, Patricia; Tracy, Bliss; Ping, Tilly; Baweja, Anar; Wickstrom, Mark; Sidhu, Narinder; Hiebert, Linda

    2007-03-01

    Northern peoples can receive elevated radiation doses (1- 10 mSv/y) from transfer of polonium-210 (210Po) through the lichen-caribou-human food chain. Ingested 210Po is primarily blood-borne and thus many of its short range alpha particles irradiate the endothelial cells lining the blood vessels. The relative biological effectiveness (RBE) of alpha particles vs. x-rays was examined in porcine aortic endothelial cells as a surrogate for understanding what might happen to human endothelial cells in northern populations consuming traditional foods. Cultured porcine aortic endothelial cells were exposed to x-ray and 210Po alpha particle radiation. Alpha irradiation was applied to the cell cultures internally via the culture medium and externally, using thin-bottomed culture dishes. The results given here are based on the external irradiation method, which was found to be more reliable. Dose-response curves were compared for four lethal endpoints (cell viability, live cell fraction, release of lactate dehydrogenase [LDH] and clonogenic survival) to determine the relative biological effectiveness (RBE) of alpha radiation. The alpha RBE for porcine cells varied from 1.6-21, depending on the endpoint: 21.2+/-4.5 for cell viability, 12.9+/-2.7 for decrease in live cell number, 5.3+/-0.4 for LDH release to the medium but only 1.6 +/-0.1 for clonogenic survival. The low RBE of 1.6 was due to x-ray hypersensitivity of endothelial cells at low doses.

  11. Examination of GyE system for HIMAC carbon therapy

    International Nuclear Information System (INIS)

    Kanai, Tatsuaki; Matsufuji, Naruhiro; Miyamoto, Tadaaki; Mizoe, Junetsu; Kamada, Tadashi; Tsuji, Hiroshi; Kato, Hirotoshi; Baba, Masayuki; Tsujii, Hirohiko

    2006-01-01

    Purpose: A retrospective analysis was made to examine appropriateness in the estimation of the biologic effectiveness of carbon-ion radiotherapy using resultant data from clinical trials at the heavy-ion medical accelerator complex (HIMAC) at the National Institute of Radiological Sciences in Chiba, Japan. Methods and Materials: At HIMAC, relative biologic effectiveness (RBE) values of therapeutic carbon beams were determined based on experimental results of cell responses, on values expected with the linear-quadratic model, and based on experiences with neutron therapy. We use fixed RBE values independent of dose levels, although this apparently contradicts radiobiologic observations. Our RBE system depends only on LET of the heavy-ion radiation fields. With this RBE system, over 2,000 patients have been treated by carbon beams. With data from these patients, the local control rate of non-small-cell lung cancer was analyzed to verify the clinical RBE of the carbon beam. The local control rate was compared with rates published by groups from Gunma University and Massachusetts General Hospital. Using a simplified tumor control probability (TCP) model, clinical RBE values were obtained for different levels of TCP. Results: For the 50% level of the clinical TCP, the RBE values nearly coincide with those for in vitro human salivary gland cell survival at 10%. For the higher levels of clinical TCP, the RBE values approach closer to those adapted in clinical trials at HIMAC

  12. The RB/E2F pathway and regulation of RNA processing

    Energy Technology Data Exchange (ETDEWEB)

    Ahlander, Joseph [Department of Molecular and Cellular Biology, 1007 East Lowell Street, University of Arizona, Tucson, AZ 85721 (United States); Bosco, Giovanni, E-mail: gbosco@email.arizona.edu [Department of Molecular and Cellular Biology, 1007 East Lowell Street, University of Arizona, Tucson, AZ 85721 (United States)

    2009-07-03

    The retinoblastoma tumor suppressor protein (RB) is inactivated in a majority of cancers. RB restricts cell proliferation by inhibiting the E2F family of transcription factors. The current model for RB/E2F function describes its role in regulating transcription at gene promoters. Whether the RB or E2F proteins might play a role in gene expression beyond transcription initiation is not well known. This review describes evidence that points to a novel role for the RB/E2F network in the regulation of RNA processing, and we propose a model as a framework for future research. The elucidation of a novel role of RB in RNA processing will have a profound impact on our understanding of the role of this tumor suppressor family in cell and developmental biology.

  13. Experiment designed to measure the RBE of tritium for the induction of myeloid leukaemia in animals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J R; Myers, D K; Gragtmans, N J

    1986-01-01

    The range in RBE vales measured for tritium can be attributed to differences in the biological endpoints measured, the reference radiation to which the effects of tritium were compared, and the tritium dosimetry of the particular study. Since the principal risk of low-level irradiation is the induction of cancers, it would be desirable to utilise this endpoint in tritium RBE experiments if these experiments are to be used to evaluate the quality factor for tritium. Furthermore, it would be desirable to use 200 k Vp X rays as the reference radiation since this radiation was suggested by ICRP as the standard reference to be used in the calculation of dose equivalents. Acute myeloid leukaemia is one of the earliest recognised examples of radiogenic cancer in humans and this endpoint has also been the subject of animal studies. A brief review is given of these animal studies to see if this endpoint is suitable for an experiment to measure the tritium RBE relative to 200 k Vp X rays. It was concluded that the male CBA/H mouse would be a suitable species and an experiment involving 5000 animals in four to five year study would be required to provide a useful estimate of the RBE for tritium.

  14. Limiting values for the RBE of fission neutrons at low doses for life shortening in mice

    International Nuclear Information System (INIS)

    Storer, J.B.; Mitchell, T.J.

    1984-01-01

    The authors have analyzed recently published data on the effects of low doses of fission neutrons on the mean survival times of mice. The analysis for single-dose exposures was confined to doses of 20 rad or less, while for fractionated exposures only total doses of 80 rad or less were considered. They fitted the data to the frequently used power function model: life shortening = βD/sup γ/, where D is the radiation dose. They show that, at low doses per fraction, either the effects are not additive or the dose-effect curve for single exposures cannot show a greater negative curvature than about the 0.9 power of dose. Analysis of the data for γ rays showed that an exponent of 1.0 gave an acceptable fit. They conclude that at neutron doses of 20 rad or less the RBE for life shortening is constant and ranges from 13 to 22 depending on mouse strain and sex

  15. Theory of RBE. Third triennial report, 1 January 1967--31 December 1975

    International Nuclear Information System (INIS)

    Katz, R.

    1975-09-01

    From a single set of themes, the theory of RBE has developed a picture of the response of many biological, physical, and chemical systems to radiations of different quality, that depends on a model of the structure of the tracks of nuclear projectiles in condensed matter. Its characterizations arise from the tracks of heavy ions in nuclear emulsions, as extended to accommodate biological cells. Most recently emulsions have been identified whose radiosensitivity changes with radiation quality parallel those of biological cells. From experimentally determined radiosensitivity parameters, the theory predicts response to a range of radiations, and includes synergistic effects of mixed radiation fields, making it possible to calculate the RBE of a mixed field of neutrons and gamma-rays, and to specify the dosimetric measurements required to make these predictions

  16. Calculation and experimental verification of the RBE-weighted dose for scanned ion beams in the presence of target motion

    International Nuclear Information System (INIS)

    Gemmel, A; Rietzel, E; Kraft, G; Durante, M; Bert, C

    2011-01-01

    We present an algorithm suitable for the calculation of the RBE-weighted dose for moving targets with a scanned particle beam. For verification of the algorithm, we conducted a series of cell survival measurements that were compared to the calculations. Calculation of the relative biological effectiveness (RBE) with respect to tumor motion was included in the treatment planning procedure, in order to fully assess its impact on treatment delivery with a scanned ion beam. We implemented an algorithm into our treatment planning software TRiP4D which allows determination of the RBE including its dependence on target tissue, absorbed dose, energy and particle spectra in the presence of organ motion. The calculations are based on time resolved computed tomography (4D-CT) and the corresponding deformation maps. The principal of the algorithm is illustrated in in silico simulations that provide a detailed view of the different compositions of the energy and particle spectra at different target positions and their consequence on the resulting RBE. The calculations were experimentally verified with several cell survival measurements using a dynamic phantom and a scanned carbon ion beam. The basic functionality of the new dose calculation algorithm has been successfully tested in in silico simulations. The algorithm has been verified by comparing its predictions to cell survival measurements. Four experiments showed in total a mean difference (standard deviation) of −1.7% (6.3%) relative to the target dose of 9 Gy (RBE). The treatment planning software TRiP is now capable to calculate the patient relevant RBE-weighted dose in the presence of target motion and was verified against cell survival measurements.

  17. Characterization of relative biological effectiveness for conventional radiation therapy: a comparison of clinical 6 MV X-rays and 137Cs.

    Science.gov (United States)

    Howard, Michelle; Beltran, Chris; Sarkaria, Jann; Herman, Michael G

    2017-09-01

    Various types of radiation are utilized in the treatment of cancer. Equal physical doses of different radiation types do not always result in the same amount of biological damage. In order to account for these differences, a scaling factor known as the relative biological effectiveness (RBE) can be used. 137Cesium (137Cs) has been used as a source of radiation in a significant body of radiation therapy research. However, high-energy X-rays, such as 6 MV X-rays, are currently used clinically to treat patients. To date, there is a gap in the literature regarding the RBE comparison of these two types of radiation. Therefore, the purpose of this study was to investigate the RBE of 137Cs relative to that of 6 MV X-rays. To determine the RBE, five cell lines were irradiated [Chinese hamster ovary (CHO); human lung adenocarcinoma (A549); human glioma (U251); human glioma (T98); and human osteosarcoma (U2OS)] by both types of radiation and assessed for cell survival using a clonogenic assay. Three of the five cell lines resulted in RBE values of ~1.00 to within 11% for all survival fractions, showing the physical and biological dose for these two types of radiation were equivalent. The other two cell lines gave RBE values differing from 1.00 by up to 36%. In conclusion, the results show the range in biological effect seen between cell lines, and therefore cell type must be considered when characterizing RBE. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  18. Rio Blanco gas composition: preproduction testing of the RBE-01 wellhead

    International Nuclear Information System (INIS)

    Smith, C.F.; Fontanilla, J.E.

    1976-01-01

    The chemical composition and radionuclide concentration of Rio Blanco gas samples collected prior to the production testing of the RBE-01 well and analyzed at LLL are presented. The analytical procedures and their uncertainties are briefly summarized. Information that associates the analytical data with the field operations is included

  19. Relative biological effectiveness (RBE) of fast neutrons with the Dunning rat prostate tumor R3327-HI

    International Nuclear Information System (INIS)

    Wenz, F.; Lohr, F.; Peschke, P.; Wolber, G.; Hoever, K.H.; Hahn, E.W.

    1993-01-01

    Human prostate tumors are known to be good candidates for neutron therapy. The Dunning rat prostate tumor system R3327 was found in many studies to be an excellent model for human prostate tumors. There is still a paucity of studies on the response of the Dunning tumors to fast neutrons. Tumors of the R3327-HI subline are moderately well differentiated and mucin producing. They show one euploid cell population, a bromodeoxyuridine labelling index of 5%, a potential doubling time of 8.9 days, a volume doubling time of about ten days and a cell loss rate of 10%. Tumors were transplanted s.c. in the distal thigh of Copenhagen rats and treated with 60 Co-photons (10, 20, 30, 40 Gy, 45 cGy/min) and 14-MeV-neutrons (8, 10, 12 Gy, 7 to 11 cGy/min). Tumor volumes were measured twice weekly. Growth delay was defined as time in days until the tumors reached twice their treatment volume. Linear regressions on the median growth delays of the different treatment groups were calculated. The ratio of the neutron- and photon-slopes yielded an RBE of 3.1±0.3. Additionally isoeffect-RBE values between 2.3 and 2.6 were graphically estimated. (orig.) [de

  20. RBE of cells irradiated by carbon ions

    International Nuclear Information System (INIS)

    Li Wenjian; Zhou Guangming; Wei Zengquan; Wang Jufang; Dang Bingrong; Li Qiang; Xie Hongmei

    2002-01-01

    The mouse melanoma cells (B16), human cervical squamous carcinoma cells (HeLa), Chinese hamster pulmonary cells V79, and human hepatoma cells (SMMC-7721) were collected for studying. The cells of 5 x 10 5 /ml were seeded in 35 mm diameter petri dish and allowed to grow one day, and then the medium in petri dishes was removed away, the cells were washed once with phosphate-buffered saline (PBS), petri dishes was covered with 4μm thickness Mylar film. The cells were irradiated by 12 C ion beam with LETs of 125.5, 200, 700 keV/μm in water generated from HIRFL (Heavy Ion Research Facility in Lanzhou). For 60 Co γ-ray experiment, the cells of 5 x 10 4 /ml were grown in 20 ml culture flasks including 1.5 ml cell suspension and directly used for irradiation. Following irradiation, the cells were trypsinized, counted, plated at appropriate densities in growth medium and then seeded in 60 mm diameter culture dishes. Each dish was filled 4 ml standard medium, and incubated for 8-12 days at 37 degree C incubator containing 5% CO 2 . The cultures were then rinsed with PBS buffer at pH 6.8, fixed with Carnoy's fluid, stained for 8 min with Giemsa (1:20, pH 6.8), and colonies containing more than 50 cells were scored. Their relative biological effectivenesses (RBE) were investigated. The results show that RBE depends on cellular types and increases with increasing of cellular survival level when LET is at 125.5 keV/μm, and decreases with increasing LET when LET ≥ 125.5 keV/μm

  1. Theory of RBE. Fifth triennial report, 1 January 1967-31 December 1981

    International Nuclear Information System (INIS)

    Katz, R.

    1981-07-01

    A single theme, that the response of a detector to gamma-rays (interpreted probabilistically through an extension of target theory) can be mapped into the region surrounding the path of an energetic heavy ion, through the local dose deposited by its delta-rays, has been the continuing basis of the present research. In order to systematize the understanding of RBE we have introduced new concepts to create a predictive theory of radiation response, of the structure of particle tracks, in a wide range of physical and biological systems. We have built a theory that is more generally applicable, to physical as well as to biological detectors, using the same basic concepts and operationally defined parameters. This procedure enables us to make quantitative experimental tests of the validity of our conceptual structure. We have created a systematic classification of detector properties, and have shown how their response varies with the numerical values of detector parameters within these classifications. Especially for 1-hit detection, our theory is universally accepted and applied. Originally created to explain the RBE of dry enzymes and viruses, it has been extended to scintillation counters, to particle tracks in nuclear emulsions, to thermoluminescent dosimeters, to lyo-luminescence, to single strand breaks in DNA, to the formation of color centers in crystals, and onwards. The extension of this conceptual system to biology required the many-hit detector, with its potential for the accumulation of sub-lethal damage. We have predicted the response of biological cells in high LET environments from this theory. It has served as the stimulus for discovering many hit physical systems (emulsions, photoresists) which respond preferentially to high LET radiations

  2. Linear Energy Transfer-Guided Optimization in Intensity Modulated Proton Therapy: Feasibility Study and Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, Drosoula, E-mail: dgiantsoudi@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grassberger, Clemens; Craft, David; Niemierko, Andrzej; Trofimov, Alexei; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2013-09-01

    Purpose: To investigate the feasibility and potential clinical benefit of linear energy transfer (LET) guided plan optimization in intensity modulated proton therapy (IMPT). Methods and Materials: A multicriteria optimization (MCO) module was used to generate a series of Pareto-optimal IMPT base plans (BPs), corresponding to defined objectives, for 5 patients with head-and-neck cancer and 2 with pancreatic cancer. A Monte Carlo platform was used to calculate dose and LET distributions for each BP. A custom-designed MCO navigation module allowed the user to interpolate between BPs to produce deliverable Pareto-optimal solutions. Differences among the BPs were evaluated for each patient, based on dose–volume and LET–volume histograms and 3-dimensional distributions. An LET-based relative biological effectiveness (RBE) model was used to evaluate the potential clinical benefit when navigating the space of Pareto-optimal BPs. Results: The mean LET values for the target varied up to 30% among the BPs for the head-and-neck patients and up to 14% for the pancreatic cancer patients. Variations were more prominent in organs at risk (OARs), where mean LET values differed by a factor of up to 2 among the BPs for the same patient. An inverse relation between dose and LET distributions for the OARs was typically observed. Accounting for LET-dependent variable RBE values, a potential improvement on RBE-weighted dose of up to 40%, averaged over several structures under study, was noticed during MCO navigation. Conclusions: We present a novel strategy for optimizing proton therapy to maximize dose-averaged LET in tumor targets while simultaneously minimizing dose-averaged LET in normal tissue structures. MCO BPs show substantial LET variations, leading to potentially significant differences in RBE-weighted doses. Pareto-surface navigation, using both dose and LET distributions for guidance, provides the means for evaluating a large variety of deliverable plans and aids in

  3. Linear Energy Transfer-Guided Optimization in Intensity Modulated Proton Therapy: Feasibility Study and Clinical Potential

    International Nuclear Information System (INIS)

    Giantsoudi, Drosoula; Grassberger, Clemens; Craft, David; Niemierko, Andrzej; Trofimov, Alexei; Paganetti, Harald

    2013-01-01

    Purpose: To investigate the feasibility and potential clinical benefit of linear energy transfer (LET) guided plan optimization in intensity modulated proton therapy (IMPT). Methods and Materials: A multicriteria optimization (MCO) module was used to generate a series of Pareto-optimal IMPT base plans (BPs), corresponding to defined objectives, for 5 patients with head-and-neck cancer and 2 with pancreatic cancer. A Monte Carlo platform was used to calculate dose and LET distributions for each BP. A custom-designed MCO navigation module allowed the user to interpolate between BPs to produce deliverable Pareto-optimal solutions. Differences among the BPs were evaluated for each patient, based on dose–volume and LET–volume histograms and 3-dimensional distributions. An LET-based relative biological effectiveness (RBE) model was used to evaluate the potential clinical benefit when navigating the space of Pareto-optimal BPs. Results: The mean LET values for the target varied up to 30% among the BPs for the head-and-neck patients and up to 14% for the pancreatic cancer patients. Variations were more prominent in organs at risk (OARs), where mean LET values differed by a factor of up to 2 among the BPs for the same patient. An inverse relation between dose and LET distributions for the OARs was typically observed. Accounting for LET-dependent variable RBE values, a potential improvement on RBE-weighted dose of up to 40%, averaged over several structures under study, was noticed during MCO navigation. Conclusions: We present a novel strategy for optimizing proton therapy to maximize dose-averaged LET in tumor targets while simultaneously minimizing dose-averaged LET in normal tissue structures. MCO BPs show substantial LET variations, leading to potentially significant differences in RBE-weighted doses. Pareto-surface navigation, using both dose and LET distributions for guidance, provides the means for evaluating a large variety of deliverable plans and aids in

  4. SU-E-T-547: Modeling Biological Response to Proton Irradiation and Evaluating Its Potential Clinical Consequences

    Energy Technology Data Exchange (ETDEWEB)

    Taleei, R; Peeler, C; Guan, F; Patel, D; Titt, U; Mirkovic, D; Grosshans, D; Mohan, R [Departments of Radiation Physics and Radiation Oncology, The University of Texas, MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: In addition to physical uncertainties, proton therapy may also be associated with biologic uncertainties. Currently a generic RBE value of 1.1 is used for treatment planning. In this work the effects of variable RBE, in comparison to a fixed RBE, were evaluated by calculating the effective dose for proton treatments. Methods: The repair misrepair fixation (RMF) model was used to calculate variable proton RBEs. The RBE weighted spread-out Bragg peak (SOBP) dose in water phantom was calculated using Monte Carlo simulation and compared to 1.1 weighted SOBP dose. A head and neck proton treatment was used to evaluate the potential effects, by comparing the head and neck treatment plan computed with a commercial treatment planning system that incorporates fixed RBE of 1.1 and a Monte Carlo treatment planning system that incorporates variable RBE. Results: RBE calculations along the depth of SOBP showed that the RBE at the entrance is approximately 1 and reaches 1.1 near the center of the SOBP. However, in distal regions the RBE rises to higher values (up to 3.5 depending on the cell type). Comparison of commercial treatment plans using a fixed RBE of 1.1 and Monte Carlo using variable RBE showed noticeable differences in the effective dose distributions. Conclusion: The comparison of the treatment planning with fixed and variable RBE shows that using commercial treatment planning systems that incorporate fixed RBE (1.1) could Result in overestimation of the effective dose to part of head and neck target volumes, while underestimating the effective dose to the normal tissue beyond the tumor. The accurate variable RBE as a function of proton beam energy in patient should be incorporated in treatment planning to improve the accuracy of effective dose calculation.

  5. RBE of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells

    International Nuclear Information System (INIS)

    Tsubouchi, Susumu; Fukutsu, Kumiko; Itsukaichi, Hiromi

    2003-01-01

    At this fiscal year, only two times irradiation experiments with neon and helium beams were performed to obtain relative biological effectiveness (RBE) of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells in vivo. First of all this project was designed to obtain RBE of 290 MeV carbon and 400 MeV neon beams in the high linear energy transfer (LET) region for acute cell death of pancreatic islets of golden hamster (Mesocricetus auratus) in the condition of in both in vivo and in vitro systems. As mentioned in previous report, in vitro system, however, resulted in ill success. This in vitro experiment was tentatively shelved for the time being. In return in vivo experiments for low LET region of neon beams (32.5 KeV/u), carbon beams (15.0 KeV/u) and helium beams (2 KeV/u) were performed in these two years. Last year these results together with those previously obtained for 200 KeV X-ray, 70 MeV proton, 290 MeV carbon (60 KeV/u), and neon (100 KeV/u) beams were reconsidered. At this year dose response relations (25, 50, 100, 150, and 200 Gy respectively) in acute cell death of pancreatic islets studied histologically after whole body irradiation of 3 weeks young male golden hamster with lower LET helium beams (2 KeV/u) and neon beams (32.5 KeV/u). Results indicated that mean cell lethal dose (Do) of helium beams (2 KeV/u) and neon beams (32.5 KeV/u) were 38 Gy and 49 Gy, respectively. Previously obtained Do data for 200 KeV x-ray, 70 MeV proton, 290 MeV carbon (15 KeV/u), 400 MeV neon (32.5 KeV/u), 290 MeV carbon (60 KeV/u), and 400 MeV neon (100 KeV/u) beams were 37 Gy, 38 Gy, 38 Gy, 49 Gy, 75 Gy, and 200 Gy, respectively. From these data estimated RBE of neon (100 KeV/u and 32.5 KeV/u), carbon (60 KeV/u and 15.0 KeV/u), 70 MeV proton and 150 MeV helium (2 KeV/u) beams were 0.19, 0.76, 0.49, 0.97, 0.97, 0.97, respectively. Therefore the order of RBE (or radiosensitivities) of islets cells with these various heavy ion beams was

  6. The r.b.e. of different-energy neutrons as determined by human bone-marrow cell-culture techniques

    International Nuclear Information System (INIS)

    Boeyum, A.; Carsten, A.L.; Chikkappa, G.; Cook, L.; Bullis, J.; Honikel, L.; Cronkite, E.P.

    1978-01-01

    The effect of X-rays and different-energy neutrons on human bone-marrow cells was studied using two different cell-culture techniques - diffusion chamber (DC) growth and colony formation in vitro (CFU-C). Based on the survival and proliferative granulocytes in DC on day 13, the D 0 value was 80 rad with X-rays, and 117 rad as measured by the CFU-C assay. The D 0 values for neutrons depended on the radiation source and the energy level. The r.b.e. values, which dropped with increasing energy levels of mono-energetic neutrons, were (i) 0.44 MeV; DC 3.7, CFU-C 4.1; (ii) 6 MeV; DC 1.8, CFU-C 2.0; (iii) 15 MeV; DC 1.6, CFU-C 1.6; (iv) fission neutrons; DC 2.6, CFU-C 2.4. (author)

  7. Investigating the robustness of ion beam therapy treatment plans to uncertainties in biological treatment parameters

    CERN Document Server

    Boehlen, T T; Dosanjh, M; Ferrari, A; Fossati, P; Haberer, T; Mairani, A; Patera, V

    2012-01-01

    Uncertainties in determining clinically used relative biological effectiveness (RBE) values for ion beam therapy carry the risk of absolute and relative misestimations of RBE-weighted doses for clinical scenarios. This study assesses the consequences of hypothetical misestimations of input parameters to the RBE modelling for carbon ion treatment plans by a variational approach. The impact of the variations on resulting cell survival and RBE values is evaluated as a function of the remaining ion range. In addition, the sensitivity to misestimations in RBE modelling is compared for single fields and two opposed fields using differing optimization criteria. It is demonstrated for single treatment fields that moderate variations (up to +/-50\\%) of representative nominal input parameters for four tumours result mainly in a misestimation of the RBE-weighted dose in the planning target volume (PTV) by a constant factor and only smaller RBE-weighted dose gradients. Ensuring a more uniform radiation quality in the PTV...

  8. Impaired degradation followed by enhanced recycling of epidermal growth factor receptor caused by hypo-phosphorylation of tyrosine 1045 in RBE cells

    International Nuclear Information System (INIS)

    Gui, Anping; Kobayashi, Akira; Motoyama, Hiroaki; Kitazawa, Masato; Takeoka, Michiko; Miyagawa, Shinichi

    2012-01-01

    Since cholangiocarcinoma has a poor prognosis, several epidermal growth factor receptor (EGFR)-targeted therapies with antibody or small molecule inhibitor treatment have been proposed. However, their effect remains limited. The present study sought to understand the molecular genetic characteristics of cholangiocarcinoma related to EGFR, with emphasis on its degradation and recycling. We evaluated EGFR expression and colocalization by immunoblotting and immunofluorescence, cell surface EGFR expression by fluorescence-activated cell sorting (FACS), and EGFR ubiquitination and protein binding by immunoprecipitation in the human cholangiocarcinoma RBE and immortalized cholangiocyte MMNK-1 cell lines. Monensin treatment and Rab11a depletion by siRNA were adopted for inhibition of EGFR recycling. Upon stimulation with EGF, ligand-induced EGFR degradation was impaired and the expression of phospho-tyrosine 1068 and phospho-p44/42 MAPK was sustained in RBE cells as compared with MMNK-1 cells. In RBE cells, the process of EGFR sorting for lysosomal degradation was blocked at the early endosome stage, and non-degradated EGFR was recycled to the cell surface. A disrupted association between EGFR and the E3 ubiquitin ligase c-Cbl, as well as hypo-phosphorylation of EGFR at tyrosine 1045 (Tyr1045), were also observed in RBE cells. In RBE cells, up-regulation of EGFR Tyr1045 phosphorylation is a potentially useful molecular alteration in EGFR-targeted therapy. The combination of molecular-targeted therapy determined by the characteristics of individual EGFR phosphorylation events and EGFR recycling inhibition show promise in future treatments of cholangiocarcinoma

  9. Direct evaluation of radiobiological parameters from clinical data in the case of ion beam therapy: an alternative approach to the relative biological effectiveness

    International Nuclear Information System (INIS)

    Cometto, A; Russo, G; Giordanengo, S; Marchetto, F; Cirio, R; Attili, A; Bourhaleb, F; Milian, F M

    2014-01-01

    The relative biological effectiveness (RBE) concept is commonly used in treatment planning for ion beam therapy. Whether models based on in vitro/in vivo RBE data can be used to predict human response to treatments is an open issue. In this work an alternative method, based on an effective radiobiological parameterization directly derived from clinical data, is presented. The method has been applied to the analysis of prostate cancer trials with protons and carbon ions. Prostate cancer trials with proton and carbon ion beams reporting 5 year-local control (LC5) and grade 2 (G2) or higher genitourinary toxicity rates (TOX) were selected from literature to test the method. Treatment simulations were performed on a representative subset of patients to produce dose and linear energy transfer distribution, which were used as explicative physical variables for the radiobiological modelling. Two models were taken into consideration: the microdosimetric kinetic model (MKM) and a linear model (LM). The radiobiological parameters of the LM and MKM were obtained by coupling them with the tumor control probability and normal tissue complication probability models to fit the LC5 and TOX data through likelihood maximization. The model ranking was based on the Akaike information criterion. Results showed large confidence intervals due to the limited variety of available treatment schedules. RBE values, such as RBE = 1.1 for protons in the treated volume, were derived as a by-product of the method, showing a consistency with current approaches. Carbon ion RBE values were also derived, showing lower values than those assumed for the original treatment planning in the target region, whereas higher values were found in the bladder. Most importantly, this work shows the possibility to infer the radiobiological parametrization for proton and carbon ion treatment directly from clinical data. (paper)

  10. RBE of the NCT beam at Petten (The Netherlands) for intestinal crypt regeneration in mice

    International Nuclear Information System (INIS)

    Gueulette, J.; Coster, B.M. de; Wambersie, A.; Stecher-Rasmussen, F.; Huiskamp, R.; Moss, R.; Morrissey, J.

    2000-01-01

    RBE of the BNCT epithermal neutron beam at Petten (The Netherlands) has been determined for intestinal crypt regeneration in mice i.e. an in vivo system. No boron was administered. This experiment is part of an IAEA programme aiming at intercomparing radiobiologically the NCT neutron beams of different facilities world-wide. Six MV photons were used as the reference radiation. For the NCT beam at Petten, irradiation times ranging between 1 and 3 hours were applied. These low dose rate irradiations (∼3 Gy/hour) were found ∼2.4 more effective than acute photon irradiations. This type of experiment - repeated at different BNCT facilities - will improve harmonisation in the radiobiological specification of NCT neutron beams and facilitate exchange of clinical information. (author)

  11. Relative biological effectiveness (RBE) of fission neutrons and gamma rays at occupational exposure levels: Volume 1, Studies on the genetic effects in mice of 60 equal once-weekly exposures to fission neutrons and gamma rays

    International Nuclear Information System (INIS)

    Grahn, D.; Carnes, B.A.

    1987-10-01

    The relative biological effectiveness (RBE) values for low doses of fission neutrons compared to 60 Co gamma rays were determined with four separate assessments of genetic damage induced in young hybrid male mice. Both radiations were delivered at low dose levels over about one-half the adult lifetime as 60 once-weekly exposures. Genetic damage assessed included both transient and residual injury. The latter is more critical, as residual genetic injury can be transmitted to subsequent generations long after the radiation exposures have ceased. Assays were performed periodically during the 60-week exposure period and at 10 or more weeks after the irradiations had terminated. RBE values, with few exceptions, ranged between 5 and 15 for transient injury and between 25 and 50 for different types of residual genetic injury. The most important form of residual genetic damage in this study was the balanced reciprocal chromosome translocation. These translocations continue to be transmitted throughout reproductive life and can lead to reduced fertility and increased prenatal mortality. The best estimate of the RBE value for translocations was 45 +- 10. Implications and recommendations with regard to the neutron quality factor will be presented conjointly with the findings from the data obtained in this same project on life shortening and on the risks of incidence or death from neoplastic disease. 64 refs., 23 tabs

  12. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    International Nuclear Information System (INIS)

    Chaudhary, Pankaj; Marshall, Thomas I.; Perozziello, Francesca M.; Manti, Lorenzo; Currell, Frederick J.; Hanton, Fiona; McMahon, Stephen J.; Kavanagh, Joy N.; Cirrone, Giuseppe Antonio Pablo; Romano, Francesco; Prise, Kevin M.; Schettino, Giuseppe

    2014-01-01

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning

  13. Controlling Depth of Cellular Quiescence by an Rb-E2F Network Switch

    Directory of Open Access Journals (Sweden)

    Jungeun Sarah Kwon

    2017-09-01

    Full Text Available Quiescence is a non-proliferative cellular state that is critical to tissue repair and regeneration. Although often described as the G0 phase, quiescence is not a single homogeneous state. As cells remain quiescent for longer durations, they move progressively deeper and display a reduced sensitivity to growth signals. Deep quiescent cells, unlike senescent cells, can still re-enter the cell cycle under physiological conditions. Mechanisms controlling quiescence depth are poorly understood, representing a currently underappreciated layer of complexity in growth control. Here, we show that the activation threshold of a Retinoblastoma (Rb-E2F network switch controls quiescence depth. Particularly, deeper quiescent cells feature a higher E2F-switching threshold and exhibit a delayed traverse through the restriction point (R-point. We further show that different components of the Rb-E2F network can be experimentally perturbed, following computer model predictions, to coarse- or fine-tune the E2F-switching threshold and drive cells into varying quiescence depths.

  14. Quality assurance (QA) program in BNCT. RBE of 7 NCT beams for intestinal crypt regeneration in mice

    International Nuclear Information System (INIS)

    John, Gueulette; De Coster, Blanche-Marie; Wambersie, Andre; Gregoire, Vincent; Rasmussen, Finn S.; Auterinen, Iiro; Binns, Peter; Blaumann, Herman; Matsumura, Akira; Liu Hongming

    2006-01-01

    The epithermal neutron beams presently used for Neutron Capture Therapy (NCT) differ substantially in their composition (relative contribution of the different dose components to the total dose), in their dose rate (depending on the power of the reactor) as well as in their general feature (e.g. beam delivery system). Each of these elements might alter significantly the biological effectiveness of the beams. Therefore, the Relative Biological Effectiveness (RBE) of 7 NCT beams was intercompared, for a reference biological system (crypt regeneration in mice) and under well-defined irradiation conditions. This type of experiments - which should facilitate the exchange of radiobiological/clinical information - should take part of the Quality Assurance (QA) procedure of all NCT beams. (author)

  15. TU-EF-304-10: Efficient Multiscale Simulation of the Proton Relative Biological Effectiveness (RBE) for DNA Double Strand Break (DSB) Induction and Bio-Effective Dose in the FLUKA Monte Carlo Radiation Transport Code

    Energy Technology Data Exchange (ETDEWEB)

    Moskvin, V; Tsiamas, P; Axente, M; Farr, J [St. Jude Children’s Research Hospital, Memphis, TN (United States); Stewart, R [University of Washington, Seattle, WA. (United States)

    2015-06-15

    Purpose: One of the more critical initiating events for reproductive cell death is the creation of a DNA double strand break (DSB). In this study, we present a computationally efficient way to determine spatial variations in the relative biological effectiveness (RBE) of proton therapy beams within the FLUKA Monte Carlo (MC) code. Methods: We used the independently tested Monte Carlo Damage Simulation (MCDS) developed by Stewart and colleagues (Radiat. Res. 176, 587–602 2011) to estimate the RBE for DSB induction of monoenergetic protons, tritium, deuterium, hellium-3, hellium-4 ions and delta-electrons. The dose-weighted (RBE) coefficients were incorporated into FLUKA to determine the equivalent {sup 6}°60Co γ-ray dose for representative proton beams incident on cells in an aerobic and anoxic environment. Results: We found that the proton beam RBE for DSB induction at the tip of the Bragg peak, including primary and secondary particles, is close to 1.2. Furthermore, the RBE increases laterally to the beam axis at the area of Bragg peak. At the distal edge, the RBE is in the range from 1.3–1.4 for cells irradiated under aerobic conditions and may be as large as 1.5–1.8 for cells irradiated under anoxic conditions. Across the plateau region, the recorded RBE for DSB induction is 1.02 for aerobic cells and 1.05 for cells irradiated under anoxic conditions. The contribution to total effective dose from secondary heavy ions decreases with depth and is higher at shallow depths (e.g., at the surface of the skin). Conclusion: Multiscale simulation of the RBE for DSB induction provides useful insights into spatial variations in proton RBE within pristine Bragg peaks. This methodology is potentially useful for the biological optimization of proton therapy for the treatment of cancer. The study highlights the need to incorporate spatial variations in proton RBE into proton therapy treatment plans.

  16. Microdosimetry spectra and RBE of 1H, 4He, 7Li and 12C nuclei in water studied with Geant4

    International Nuclear Information System (INIS)

    Burigo, Lucas; Pshenichnov, Igor; Mishustin, Igor; Bleicher, Marcus

    2014-01-01

    A Geant4-based Monte Carlo model for Heavy-Ion Therapy (MCHIT) is used to study radiation fields of 1 H, 4 He, 7 Li and 12 C beams with similar ranges (∼160–180 mm) in water. Microdosimetry spectra are simulated for wall-less and walled Tissue Equivalent Proportional Counters (TEPCs) placed outside or inside a phantom, as in experiments performed, respectively, at NIRS, Japan and GSI, Germany. The impact of fragmentation reactions on microdosimetry spectra is investigated for 4 He, 7 Li and 12 C, and contributions from nuclear fragments of different charge are evaluated for various TEPC positions in the phantom. The microdosimetry spectra measured on the beam axis are well described by MCHIT, in particular, in the vicinity of the Bragg peak. However, the simulated spectra for the walled TEPC far from the beam axis are underestimated. Relative Biological Effectiveness (RBE) of the considered beams is estimated using a modified microdosimetric-kinetic model. Calculations show a similar rise of the RBE up to 2.2–2.9 close to the Bragg peak for helium, lithium and carbon beams compared to the modest values of 1–1.2 at the plateau region. Our results suggest that helium and lithium beams are also promising options for cancer therapy

  17. Dynamical behaviors of Rb-E2F pathway including negative feedback loops involving miR449.

    Science.gov (United States)

    Yan, Fang; Liu, Haihong; Hao, Junjun; Liu, Zengrong

    2012-01-01

    MiRNAs, which are a family of small non-coding RNAs, regulate a broad array of physiological and developmental processes. However, their regulatory roles have remained largely mysterious. E2F is a positive regulator of cell cycle progression and also a potent inducer of apoptosis. Positive feedback loops in the regulation of Rb-E2F pathway are predicted and shown experimentally. Recently, it has been discovered that E2F induce a cluster of miRNAs called miR449. In turn, E2F is inhibited by miR449 through regulating different transcripts, thus forming negative feedback loops in the interaction network. Here, based on the integration of experimental evidence and quantitative data, we studied Rb-E2F pathway coupling the positive feedback loops and negative feedback loops mediated by miR449. Therefore, a mathematical model is constructed based in part on the model proposed in Yao-Lee et al. (2008) and nonlinear dynamical behaviors including the stability and bifurcations of the model are discussed. A comparison is given to reveal the implication of the fundamental differences of Rb-E2F pathway between regulation and deregulation of miR449. Coherent with the experiments it predicts that miR449 plays a critical role in regulating the cell cycle progression and provides a twofold safety mechanism to avoid excessive E2F-induced proliferation by cell cycle arrest and apoptosis. Moreover, numerical simulation and bifurcation analysis shows that the mechanisms of the negative regulation of miR449 to three different transcripts are quite distinctive which needs to be verified experimentally. This study may help us to analyze the whole cell cycle process mediated by other miRNAs more easily. A better knowledge of the dynamical behaviors of miRNAs mediated networks is also of interest for bio-engineering and artificial control.

  18. Generalized concept of the LET-RBE relationship of radiation-induced chromosome aberration and cell death

    International Nuclear Information System (INIS)

    Takatsuji, Toshihiro; Yoshikawa, Isao; Sasaki, Masao S.

    1999-01-01

    The frequency of chromosome aberrations per traversal of a nucleus by a charged particle at the low dose limit increases proportionally to the square of the linear energy transfer (LET), peaks at about 100 keV/μm and then decreases with further increase of LET. This has long been interpreted as an excessive energy deposition over the necessary energy required to produce a biologically effective event. Here, we present an alternative interpretation. Cell traversed by a charged particle has certain probability to receive lethal damage leading to direct death. Such events may increase with an increase of LET and the number of charged particles traversing the cell. Assuming that the lethal damage is distributed according to a Poisson distribution, the probability that a cell has no such damage is expressed by e -cLx , where c is a constant, L is LET, and x is the number of charged particles traversing the cell. From these assumptions, the frequency of chromosome aberration in surviving cells can be described by Y=αSD+βS 2 D 2 with the empirical relation Y=αD+βD 2 in the low LET region, where S=e -cL , α is a value proportional to LET, β is a constant, and D is the absorbed dose. This model readily explains the empirically established relationship between LET and relative biological effectiveness (RBE). The model can also be applied to clonogenic survival. If cells can survive and they have neither unstable chromosome aberrations nor other lethal damage, the LET-RBE relationship for clonogenic survival forms a humped curve. The relationship between LET and inactivation cross-section becomes proportional to the square of LET in the low LET region when the frequency of a directly lethal events is sufficiently smaller than unity, and the inactivation cross-section saturates to the cell nucleus cross-sectional area with an increase in LET in the high LET region. (author)

  19. Inverse gamma ray dose rate effect in californium-252 RBE experiment with human T-1 cells irradiated in vitro

    International Nuclear Information System (INIS)

    Todd, P.; Feola, J.M.

    1986-01-01

    Metabolically deoxygenated suspensions of human T-1 cells were used to determine the RBE in hypoxia of low dose rate (LDR) Cf-252 radiation compared to LDR gamma radiation. Based upon the initial portion of the survival curves the RBE was 5.0 ± 1.0 for all components of the Cf-252 radiation and 7.1 ± 1.7 for the neutrons alone. An inverse dose rate effect was observed for LDR gamma radiation in which greater cell sensitivity was observed at lower dose rates and longer irradiation periods. It was demonstrated that there was little or no sublethal damage repair or cell progression during LDR at 21 deg C, and the observed decrease in cell survival probability with increasing irradiation time at a given dose was attributable to reoxygenation of the cell suspensions during the course of LDR exposures. (Auth.)

  20. Theory of RBE. Annual technical progress report, 1 January--31 December, 1994

    International Nuclear Information System (INIS)

    Katz, R.

    1994-01-01

    In researching the theory of RBE, attention is focused on several topics of importance. They include: improving knowledge of the radial distribution of dose about the path of an energetic heavy ion in different media; calculations which have demonstrated that three Escherichia coli mutants behave as 1-hit detectors; lethal mutations in a nematode induced by gamma radiation and heavy ion beams; prevalence in cancer induction in the Harderian gland by HZE particles; subtleties in the analysis of radiobiological data; low-dose irradiation effects; high LET effects; cellular radiosensitivity parameters; and radial dose calculations for mammalian cells

  1. [miR-503-5p inhibits the proliferation of T24 and EJ bladder cancer cells by interfering with the Rb/E2F signaling pathway].

    Science.gov (United States)

    Li, Xiaohui; Han, Xingtao; Yang, Jinhui; Sun, Jiantao; Wei, Pengtao

    2017-10-01

    Objective To observe the effect of microRNA-503-5p (miR-503-5p) on the growth of T24 and EJ bladder cancer cells, and explore the possible molecular mechanism. Methods The miR-504-5p mimics or miR-NC was transfected into T24 and EJ cells. The target gene of miR-503-5p was predicted by bioinformatics. The expressions of E2F transcription factor 3 (E2F3) mRNA and Rb/E2F signaling pathway mRNA were detected by the real-time quantitative PCR (qPCR). The expressions of Rb/E2F signal pathway proteins E2F3, cyclin E, CDK2, Rb and p-Rb were detected by Western blotting. The cell cycle of bladder cancer cell lines was determined by flow cytometry. MTT assay and plate cloning assay were performed to observe the proliferation ability of bladder cancer cells. Results After miR-503-5p mimics transfection, the expression of miR-503-5p in bladder cancer cells significantly increased. The increased expression of miR-503-5p significantly reduced the expressions of E2F3 mRNA and Rb/E2F signaling pathway mRNA in bladder cancer cells. What's more, the expressions of Rb/E2F signal pathway proteins were down-regulated. The bladder cancer cells were arrested in G0/G1 phase, and their growth was significantly inhibited by miR-503-5p. Conclusion The miR-503-5p over-expression can inhibit the growth of bladder cancer cell lines T24 and EJ by down-regulating the expression of the Rb/E2F signaling pathway.

  2. The relationships between RBE and LET for different types of lethal damage in mammalian cells: biophysical and molecular mechanisms

    NARCIS (Netherlands)

    Barendsen, G. W.

    1994-01-01

    The relative biological effectiveness (RBE) of radiations as a function of linear energy transfer (LET) is analyzed for different types of damage causing reproductive death of mammalian cells. Survival curves are evaluated assuming a linear-quadratic dose dependence of the induction of reproductive

  3. On the dose calculation at the cellular level and its implications for the RBE of {sup 99m}Tc and {sup 123}I

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberg, R., E-mail: robert.freudenberg@uniklinikum-dresden.de; Runge, R.; Maucksch, U.; Berger, V.; Kotzerke, J. [University Hospital/Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Saxony 01307 (Germany)

    2014-06-15

    Purpose: Based on the authors’ previous findings concerning the radiotoxicity of{sup 99m}Tc, the authors compared the cellular survival under the influence of this nuclide with that following exposure to the Auger electron emitter {sup 123}I. To evaluate the relative biological effectiveness (RBE) of both radionuclides, knowledge of the absorbed dose is essential. Thus, the authors present the dose calculations and discuss the results based on different models of the radionuclide distribution. Both different target volumes and the influence of the uptake kinetics were considered. Methods: Rat thyroid PC Cl3 cells in culture were incubated with either{sup 99m}Tc or {sup 123}I or were irradiated using 200 kV x-rays in the presence or absence of perchlorate. The clonogenic cell survival was measured via colony formation. In addition, the intracellular radionuclide uptake was quantified. Single-cell dose calculations were based on Monte Carlo simulations performed using Geant4. Results: Compared with external radiation using x-rays (D{sub 37} = 2.6 Gy), the radionuclides {sup 99m}Tc (D{sub 37} = 3.5 Gy), and {sup 123}I (D{sub 37} = 3.8 Gy) were less toxic in the presence of perchlorate. In the absence of perchlorate, the amount of activity a{sub 37} that was necessary to reduce the surviving fraction (SF) to 0.37 was 22.8 times lower for {sup 99m}Tc and 12.4 times lower for {sup 123}I because of the dose increase caused by intracellular radionuclide accumulation. When the cell nucleus was considered as the target for the dose calculation, the authors found a RBE of 2.18 for {sup 99m}Tc and RBE = 3.43 for {sup 123}I. Meanwhile, regarding the dose to the entire cell, RBE = 0.75 for {sup 99m}Tc and RBE = 1.87 for {sup 123}I. The dose to the entire cell was chosen as the dose criterion because of the intracellular radionuclide accumulation, which was found to occur solely in the cytoplasm. The calculated number of intracellular decays per cell was (975 ± 109) decays

  4. Fast Biological Modeling for Voxel-based Heavy Ion Treatment Planning Using the Mechanistic Repair-Misrepair-Fixation Model and Nuclear Fragment Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kamp, Florian [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Oncology, Technische Universität München, Klinikum Rechts der Isar, München (Germany); Physik-Department, Technische Universität München, Garching (Germany); Cabal, Gonzalo [Experimental Physics–Medical Physics, Ludwig Maximilians University Munich, Garching (Germany); Mairani, Andrea [Medical Physics Unit, Centro Nazionale Adroterapia Oncologica (CNAO), Pavia (Italy); Heidelberg Ion-Beam Therapy Center, Heidelberg (Germany); Parodi, Katia [Experimental Physics–Medical Physics, Ludwig Maximilians University Munich, Garching (Germany); Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum Rechts der Isar, München (Germany); Physik-Department, Technische Universität München, Garching (Germany); Carlson, David J., E-mail: david.j.carlson@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States)

    2015-11-01

    Purpose: The physical and biological differences between heavy ions and photons have not been fully exploited and could improve treatment outcomes. In carbon ion therapy, treatment planning must account for physical properties, such as the absorbed dose and nuclear fragmentation, and for differences in the relative biological effectiveness (RBE) of ions compared with photons. We combined the mechanistic repair-misrepair-fixation (RMF) model with Monte Carlo-generated fragmentation spectra for biological optimization of carbon ion treatment plans. Methods and Materials: Relative changes in double-strand break yields and radiosensitivity parameters with particle type and energy were determined using the independently benchmarked Monte Carlo damage simulation and the RMF model to estimate the RBE values for primary carbon ions and secondary fragments. Depth-dependent energy spectra were generated with the Monte Carlo code FLUKA for clinically relevant initial carbon ion energies. The predicted trends in RBE were compared with the published experimental data. Biological optimization for carbon ions was implemented in a 3-dimensional research treatment planning tool. Results: We compared the RBE and RBE-weighted dose (RWD) distributions of different carbon ion treatment scenarios with and without nuclear fragments. The inclusion of fragments in the simulations led to smaller RBE predictions. A validation of RMF against measured cell survival data reported in published studies showed reasonable agreement. We calculated and optimized the RWD distributions on patient data and compared the RMF predictions with those from other biological models. The RBE values in an astrocytoma tumor ranged from 2.2 to 4.9 (mean 2.8) for a RWD of 3 Gy(RBE) assuming (α/β){sub X} = 2 Gy. Conclusions: These studies provide new information to quantify and assess uncertainties in the clinically relevant RBE values for carbon ion therapy based on biophysical mechanisms. We present results from

  5. Dynamical behaviors of Rb-E2F pathway including negative feedback loops involving miR449.

    Directory of Open Access Journals (Sweden)

    Fang Yan

    Full Text Available MiRNAs, which are a family of small non-coding RNAs, regulate a broad array of physiological and developmental processes. However, their regulatory roles have remained largely mysterious. E2F is a positive regulator of cell cycle progression and also a potent inducer of apoptosis. Positive feedback loops in the regulation of Rb-E2F pathway are predicted and shown experimentally. Recently, it has been discovered that E2F induce a cluster of miRNAs called miR449. In turn, E2F is inhibited by miR449 through regulating different transcripts, thus forming negative feedback loops in the interaction network. Here, based on the integration of experimental evidence and quantitative data, we studied Rb-E2F pathway coupling the positive feedback loops and negative feedback loops mediated by miR449. Therefore, a mathematical model is constructed based in part on the model proposed in Yao-Lee et al. (2008 and nonlinear dynamical behaviors including the stability and bifurcations of the model are discussed. A comparison is given to reveal the implication of the fundamental differences of Rb-E2F pathway between regulation and deregulation of miR449. Coherent with the experiments it predicts that miR449 plays a critical role in regulating the cell cycle progression and provides a twofold safety mechanism to avoid excessive E2F-induced proliferation by cell cycle arrest and apoptosis. Moreover, numerical simulation and bifurcation analysis shows that the mechanisms of the negative regulation of miR449 to three different transcripts are quite distinctive which needs to be verified experimentally. This study may help us to analyze the whole cell cycle process mediated by other miRNAs more easily. A better knowledge of the dynamical behaviors of miRNAs mediated networks is also of interest for bio-engineering and artificial control.

  6. Relative biological effectiveness (R.B.E.) of Cf-252 vs. acute Co-60 and low dose rate Cs-137 irradiation by spleen weight loss

    International Nuclear Information System (INIS)

    Maruyama, Y.; Feola, J.M.; Magura, C.; Beach, J.L.

    1986-01-01

    R.B.E. of Cf-252 on lymphoid tissue was assessed by radiation study of spleen weight loss following acute Co-60, and low dose rate (L.D.R.) Cs-137 and Cf-252 irradiations. Acute Co-60 and L.D.R. Cs-137 dose-response followed two component exponential curves with a 1.3-fold greater effect of L.D.R. Cs-137 vs. acute Co-60 on the first slope and 1.9-fold greater effect for the 2nd slope. L.D.R. Cf-252 response was 1.3 x greater than acute Co-60 but was 1.0 vs. L.D.R. Cs-137 for the first slope indicating a similar effect of Cf-252 mixed neutron/gamma radiation to L.D.R. gamma radiation in producing spleen shrinkage. There was no effect of different sequences and schedules of mixing acute Co-60 with Cf-252 irradiation observed by endogenous CFU-S survival. The R.B.E. of 1.0 - 1.9 indicates that lymphohemopoietic in vivo, presumably well oxygenated, does not respond acutely or as sensitively as hypoxic tumor where R.B.E. is 5 - 7. (author)

  7. Relative biological effectiveness of tritiated water on cultured mammalian cells at molecular and cellular level

    International Nuclear Information System (INIS)

    Okada, S.; Sakai, K.; Nakamura, N.

    1986-01-01

    Factors that affect RBE values have been investigated in cultured cells. It was shown that: (1) Different RBE values were obtained with the same tritiated water treated cells depending upon the biological end-point; this may be related to target size. (2) The RBE value for one end-point (e.g. cell killing) in different cell types was often different. In some cells, the RBE value increased with reducing dose; in other cells, the value remained constant. (3) The RBE value for tritiated water seemed to fit a general RBE-LET relationship. These results suggest that although the RBE value might vary from 1 to 2 when cells are exposed to HTO, there are situations where the value becomes higher than 2; these are associated with low dose and low dose rate exposures in some cell types. (author)

  8. Analysis of Relative Biological Effectiveness of Proton Beams and Isoeffective Dose Profiles Using Geant4

    Directory of Open Access Journals (Sweden)

    Hosseini M. A.

    2017-06-01

    Full Text Available Background: The assessment of RBE quantity in the treatment of cancer tumors with proton beams in treatment planning systems (TPS is of high significance. Given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. Objective: The main objective of this study was to assess RBE quantity of proton beams and their variations in different depths of the tumor. This dependency makes RBE values used in TPS no longer be fixed as they depend on the depth of the tumor and therefore this dependency causes some changes in the physical dose profile. Materials and Methods: The energy spectrum of protons was measured at various depths of the tumor using proton beam simulations and well as the complete simulation of a cell to a pair of DNA bases through Monte Carlo GEANT4. The resulting energy spectrum was used to estimate the number of double-strand breaks generated in cells. Finally, RBE values were calculated in terms of the penetration depth in the tumor. Results and Conclusion: The simulation results show that the RBE value not fixed terms of the depth of the tumor and it differs from the clinical value of 1.1 at the end of the dose profile and this will lead to a non-uniform absorbed dose profile. Therefore, to create a uniform impact dose area, deep-finishing systems need to be designed by taking into account deep RBE values.

  9. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    International Nuclear Information System (INIS)

    Gruen, Rebecca Antonia

    2014-01-01

    characterization of the photon dose-response curve has been found to be of particular importance for the determination of RBE. The application of the LEM IV for proton beams more correctly represents the experimentally observed increase of RBE towards the distal end of the irradiation field compared to the clinically considered constant value of 1.1. It further allowed a better systematic characterization of the increased effective range of proton beams that is a consequence of the RBE enhancement at the distal edge of the treatment field. The results of this work underline the importance of detailed RBE modeling for a long-term improvement of treatment planning in particle therapy and the better exploitation of advantages inherent to this radiation modality.

  10. Photon iso-effective dose for cancer treatment with mixed field radiation based on dose-response assessment from human and an animal model: clinical application to boron neutron capture therapy for head and neck cancer

    Science.gov (United States)

    González, S. J.; Pozzi, E. C. C.; Monti Hughes, A.; Provenzano, L.; Koivunoro, H.; Carando, D. G.; Thorp, S. I.; Casal, M. R.; Bortolussi, S.; Trivillin, V. A.; Garabalino, M. A.; Curotto, P.; Heber, E. M.; Santa Cruz, G. A.; Kankaanranta, L.; Joensuu, H.; Schwint, A. E.

    2017-10-01

    Boron neutron capture therapy (BNCT) is a treatment modality that combines different radiation qualities. Since the severity of biological damage following irradiation depends on the radiation type, a quantity different from absorbed dose is required to explain the effects observed in the clinical BNCT in terms of outcome compared with conventional photon radiation therapy. A new approach for calculating photon iso-effective doses in BNCT was introduced previously. The present work extends this model to include information from dose-response assessments in animal models and humans. Parameters of the model were determined for tumour and precancerous tissue using dose-response curves obtained from BNCT and photon studies performed in the hamster cheek pouch in vivo models of oral cancer and/or pre-cancer, and from head and neck cancer radiotherapy data with photons. To this end, suitable expressions of the dose-limiting Normal Tissue Complication and Tumour Control Probabilities for the reference radiation and for the mixed field BNCT radiation were developed. Pearson’s correlation coefficients and p-values showed that TCP and NTCP models agreed with experimental data (with r  >  0.87 and p-values  >0.57). The photon iso-effective dose model was applied retrospectively to evaluate the dosimetry in tumours and mucosa for head and neck cancer patients treated with BNCT in Finland. Photon iso-effective doses in tumour were lower than those obtained with the standard RBE-weighted model (between 10% to 45%). The results also suggested that the probabilities of tumour control derived from photon iso-effective doses are more adequate to explain the clinical responses than those obtained with the RBE-weighted values. The dosimetry in the mucosa revealed that the photon iso-effective doses were about 30% to 50% higher than the corresponding RBE-weighted values. While the RBE-weighted doses are unable to predict mucosa toxicity, predictions based on the proposed

  11. Photon iso-effective dose for cancer treatment with mixed field radiation based on dose-response assessment from human and an animal model: clinical application to boron neutron capture therapy for head and neck cancer.

    Science.gov (United States)

    González, S J; Pozzi, E C C; Monti Hughes, A; Provenzano, L; Koivunoro, H; Carando, D G; Thorp, S I; Casal, M R; Bortolussi, S; Trivillin, V A; Garabalino, M A; Curotto, P; Heber, E M; Santa Cruz, G A; Kankaanranta, L; Joensuu, H; Schwint, A E

    2017-10-03

    Boron neutron capture therapy (BNCT) is a treatment modality that combines different radiation qualities. Since the severity of biological damage following irradiation depends on the radiation type, a quantity different from absorbed dose is required to explain the effects observed in the clinical BNCT in terms of outcome compared with conventional photon radiation therapy. A new approach for calculating photon iso-effective doses in BNCT was introduced previously. The present work extends this model to include information from dose-response assessments in animal models and humans. Parameters of the model were determined for tumour and precancerous tissue using dose-response curves obtained from BNCT and photon studies performed in the hamster cheek pouch in vivo models of oral cancer and/or pre-cancer, and from head and neck cancer radiotherapy data with photons. To this end, suitable expressions of the dose-limiting Normal Tissue Complication and Tumour Control Probabilities for the reference radiation and for the mixed field BNCT radiation were developed. Pearson's correlation coefficients and p-values showed that TCP and NTCP models agreed with experimental data (with r  >  0.87 and p-values  >0.57). The photon iso-effective dose model was applied retrospectively to evaluate the dosimetry in tumours and mucosa for head and neck cancer patients treated with BNCT in Finland. Photon iso-effective doses in tumour were lower than those obtained with the standard RBE-weighted model (between 10% to 45%). The results also suggested that the probabilities of tumour control derived from photon iso-effective doses are more adequate to explain the clinical responses than those obtained with the RBE-weighted values. The dosimetry in the mucosa revealed that the photon iso-effective doses were about 30% to 50% higher than the corresponding RBE-weighted values. While the RBE-weighted doses are unable to predict mucosa toxicity, predictions based on the proposed

  12. SU-F-T-682: In-Vivo Simulation of the Relative Biological Effectiveness in Proton Therapy Using a Monte Carlo Method

    International Nuclear Information System (INIS)

    Oesten, H; Loeck, S; Wohlfahrt, P; Helmbrecht, S; Tillner, F; Schuemann, J; Luehr, A

    2016-01-01

    Purpose: In proton therapy, the relative biological effectiveness (RBE) – compared with conventional photon therapy – is routinely set to 1.1. However, experimental in vitro studies indicate evidence for the variability of the RBE. To clarify the impact on patient treatment, investigation of the RBE in a preclinical case study should be performed. Methods: The Monte Carlo software TOPAS was used to simulate the radiation field of an irradiation setup at the experimental beamline of the proton therapy facility (OncoRay) in Dresden, Germany. Simulations were performed on cone beam CT-data (CBCT) of a xenogeneous mouse with an orthotopic lung carcinoma obtained by an in-house developed small animal image-guided radiotherapy device. A homogeneous physical fraction dose of 1.8Gy was prescribed for the contoured tumor volume. Simulated dose and linear energy transfer distributions were used to estimate RBE values in the mouse based on an RBE model by Wedenberg et al. To characterize radiation sensitivity of normal and tumor tissue, α/β-ratios were taken from the literature for NB1RGB (10.1Gy) and human squamous lung cancer (6.2Gy) cell lines, respectively. Results: Good dose coverage of the target volume was achieved with a spread-out Bragg peak (SOBP). The contra-lateral lung was completely spared from receiving radiation. An increase in RBE towards the distal end of the SOBP from 1.07 to 1.35 and from 1.05 to 1.3 was observed when considering normal tissue and tumor, respectively, with the highest RBE values located distal to the target volume. Conclusion: Modeled RBE values simulated on CBCT for experimental preclinical proton therapy varied with tissue type and depth in a mouse and differed therefore from a constant value of 1.1. Further translational work will include, first, conducting preclinical experiments and, second, analogous RBE studies in patients using experimentally verified simulation settings for our clinically used patient-specific beam

  13. SU-F-T-682: In-Vivo Simulation of the Relative Biological Effectiveness in Proton Therapy Using a Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Oesten, H [OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); Massachusetts General Hospital, Boston, MA (Germany); Loeck, S; Wohlfahrt, P [OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); Helmbrecht, S [OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Tillner, F [OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); Schuemann, J [Massachusetts General Hospital, Boston, MA (United States); Luehr, A [OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitaet Dresden (Germany); German Cancer Consortium (DKTK), Dresden (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany)

    2016-06-15

    Purpose: In proton therapy, the relative biological effectiveness (RBE) – compared with conventional photon therapy – is routinely set to 1.1. However, experimental in vitro studies indicate evidence for the variability of the RBE. To clarify the impact on patient treatment, investigation of the RBE in a preclinical case study should be performed. Methods: The Monte Carlo software TOPAS was used to simulate the radiation field of an irradiation setup at the experimental beamline of the proton therapy facility (OncoRay) in Dresden, Germany. Simulations were performed on cone beam CT-data (CBCT) of a xenogeneous mouse with an orthotopic lung carcinoma obtained by an in-house developed small animal image-guided radiotherapy device. A homogeneous physical fraction dose of 1.8Gy was prescribed for the contoured tumor volume. Simulated dose and linear energy transfer distributions were used to estimate RBE values in the mouse based on an RBE model by Wedenberg et al. To characterize radiation sensitivity of normal and tumor tissue, α/β-ratios were taken from the literature for NB1RGB (10.1Gy) and human squamous lung cancer (6.2Gy) cell lines, respectively. Results: Good dose coverage of the target volume was achieved with a spread-out Bragg peak (SOBP). The contra-lateral lung was completely spared from receiving radiation. An increase in RBE towards the distal end of the SOBP from 1.07 to 1.35 and from 1.05 to 1.3 was observed when considering normal tissue and tumor, respectively, with the highest RBE values located distal to the target volume. Conclusion: Modeled RBE values simulated on CBCT for experimental preclinical proton therapy varied with tissue type and depth in a mouse and differed therefore from a constant value of 1.1. Further translational work will include, first, conducting preclinical experiments and, second, analogous RBE studies in patients using experimentally verified simulation settings for our clinically used patient-specific beam

  14. Temporal Lobe Reactions After Carbon Ion Radiation Therapy: Comparison of Relative Biological Effectiveness–Weighted Tolerance Doses Predicted by Local Effect Models I and IV

    Energy Technology Data Exchange (ETDEWEB)

    Gillmann, Clarissa, E-mail: clarissa.gillmann@med.uni-heidelberg.de [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Jäkel, Oliver [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Schlampp, Ingmar [Department of Radiation Oncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg (Germany); Karger, Christian P. [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg (Germany)

    2014-04-01

    Purpose: To compare the relative biological effectiveness (RBE)–weighted tolerance doses for temporal lobe reactions after carbon ion radiation therapy using 2 different versions of the local effect model (LEM I vs LEM IV) for the same patient collective under identical conditions. Methods and Materials: In a previous study, 59 patients were investigated, of whom 10 experienced temporal lobe reactions (TLR) after carbon ion radiation therapy for low-grade skull-base chordoma and chondrosarcoma at Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt, Germany in 2002 and 2003. TLR were detected as visible contrast enhancements on T1-weighted MRI images within a median follow-up time of 2.5 years. Although the derived RBE-weighted temporal lobe doses were based on the clinically applied LEM I, we have now recalculated the RBE-weighted dose distributions using LEM IV and derived dose-response curves with Dmax,V-1 cm³ (the RBE-weighted maximum dose in the remaining temporal lobe volume, excluding the volume of 1 cm³ with the highest dose) as an independent dosimetric variable. The resulting RBE-weighted tolerance doses were compared with those of the previous study to assess the clinical impact of LEM IV relative to LEM I. Results: The dose-response curve of LEM IV is shifted toward higher values compared to that of LEM I. The RBE-weighted tolerance dose for a 5% complication probability (TD{sub 5}) increases from 68.8 ± 3.3 to 78.3 ± 4.3 Gy (RBE) for LEM IV as compared to LEM I. Conclusions: LEM IV predicts a clinically significant increase of the RBE-weighted tolerance doses for the temporal lobe as compared to the currently applied LEM I. The limited available photon data do not allow a final conclusion as to whether RBE predictions of LEM I or LEM IV better fit better clinical experience in photon therapy. The decision about a future clinical application of LEM IV therefore requires additional analysis of temporal lobe reactions in a

  15. Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions.

    Science.gov (United States)

    Stewart, Robert D; Streitmatter, Seth W; Argento, David C; Kirkby, Charles; Goorley, John T; Moffitt, Greg; Jevremovic, Tatjana; Sandison, George A

    2015-11-07

    To account for particle interactions in the extracellular (physical) environment, information from the cell-level Monte Carlo damage simulation (MCDS) for DNA double strand break (DSB) induction has been integrated into the general purpose Monte Carlo N-particle (MCNP) radiation transport code system. The effort to integrate these models is motivated by the need for a computationally efficient model to accurately predict particle relative biological effectiveness (RBE) in cell cultures and in vivo. To illustrate the approach and highlight the impact of the larger scale physical environment (e.g. establishing charged particle equilibrium), we examined the RBE for DSB induction (RBEDSB) of x-rays, (137)Cs γ-rays, neutrons and light ions relative to γ-rays from (60)Co in monolayer cell cultures at various depths in water. Under normoxic conditions, we found that (137)Cs γ-rays are about 1.7% more effective at creating DSB than γ-rays from (60)Co (RBEDSB  =  1.017) whereas 60-250 kV x-rays are 1.1 to 1.25 times more efficient at creating DSB than (60)Co. Under anoxic conditions, kV x-rays may have an RBEDSB up to 1.51 times as large as (60)Co γ-rays. Fission neutrons passing through monolayer cell cultures have an RBEDSB that ranges from 2.6 to 3.0 in normoxic cells, but may be as large as 9.93 for anoxic cells. For proton pencil beams, Monte Carlo simulations suggest an RBEDSB of about 1.2 at the tip of the Bragg peak and up to 1.6 a few mm beyond the Bragg peak. Bragg peak RBEDSB increases with decreasing oxygen concentration, which may create opportunities to apply proton dose painting to help address tumor hypoxia. Modeling of the particle RBE for DSB induction across multiple physical and biological scales has the potential to aid in the interpretation of laboratory experiments and provide useful information to advance the safety and effectiveness of hadron therapy in the treatment of cancer.

  16. Direct Comparison of Biologically Optimized Spread-out Bragg Peaks for Protons and Carbon Ions

    International Nuclear Information System (INIS)

    Wilkens, Jan J.; Oelfke, Uwe

    2008-01-01

    Purpose: In radiotherapy with hadrons, it is anticipated that carbon ions are superior to protons, mainly because of their biological properties: the relative biological effectiveness (RBE) for carbon ions is supposedly higher in the target than in the surrounding normal tissue, leading to a therapeutic advantage over protons. The purpose of this report is to investigate this effect by using biological model calculations. Methods and Materials: We compared spread-out Bragg peaks for protons and carbon ions by using physical and biological optimization. The RBE for protons and carbon ions was calculated according to published biological models. These models predict increased RBE values in regions of high linear energy transfer (LET) and an inverse dependency of the RBE on dose. Results: For pure physical optimization, protons yield a better dose distribution along the central axis. In biologically optimized plans, RBE variations for protons were relatively small. For carbon ions, high RBE values were found in the high-LET target region, as well as in the low-dose region outside the target. This means that the LET dependency and dose dependency of the RBE can cancel each other. We show this for radioresistant tissues treated with two opposing beams, for which the predicted carbon RBE within the target volume was lower than outside. Conclusions: For tissue parameters used in this study, the model used does not predict a biologic advantage of carbon ions. More reliable model parameters and clinical trials are necessary to explore the true potential of radiotherapy with carbon ions

  17. WE-FG-BRB-04: RBEs for Human Lung Cancer Cells Exposed to Protons and Heavier Ions: Implications for Clinical Use of Charged Particles in Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Held, K. [Massachusetts General Hospital (United States)

    2016-06-15

    The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences between particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to

  18. RBE-LET relationships for different types of lethal radiation damage in mammalian cells: comparison with DNA dsb and an interpretation of differences in radiosensitivity

    NARCIS (Netherlands)

    Barendsen, G. W.

    1994-01-01

    Relative biological effectiveness (RBE), as a function of linear energy transfer (LET), is evaluated for different types of damage contributing to mammalian cell reproductive death. Survival curves are analysed assuming a linear-quadratic dose dependence of lethal lesions. The linear term represents

  19. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    International Nuclear Information System (INIS)

    Wang Jufang; Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian

    2010-01-01

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1 ) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1 . The mutation cross section saturated when LET was higher than 58.2 keV μm -1 . Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1 . The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  20. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    Science.gov (United States)

    Wang, Jufang; Lu, Dong; Wu, Xin; Sun, Haining; Ma, Shuang; Li, Renmin; Li, Wenjian

    2010-09-01

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1. The mutation cross section saturated when LET was higher than 58.2 keV μm -1. Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  1. Understanding the value added to clinical care by educational activities. Value of Education Research Group.

    Science.gov (United States)

    Ogrinc, G S; Headrick, L A; Boex, J R

    1999-10-01

    In an era of competition in health care delivery, those who pay for care are interested in supporting primarily those activities that add value to the clinical enterprise. The authors report on their 1998 project to develop a conceptual model for assessing the value added to clinical care by educational activities. Through interviews, nine key stakeholders in patient care identified five ways in which education might add value to clinical care: education can foster higher-quality care, improve work satisfaction of clinicians, have trainees provide direct clinical services, improve recruitment and retention of clinicians, and contribute to the future of health care. With this as a base, an expert panel of 13 clinical educators and investigators defined six perspectives from which the value of education in clinical care might be studied: the perspectives of health-care-oriented organizations, clinician-teachers, patients, education organizations, learners, and the community. The panel adapted an existing model to create the "Education Compass" to portray education's effects on clinical care, and developed a new set of definitions and research questions for each of the four major aspects of the model (clinical, functional, satisfaction, and cost). Working groups next drafted proposals to address empirically those questions, which were critiqued at a national conference on the topic of education's value in clinical care. The next step is to use the methods developed in this project to empirically assess the value added by educational activities to clinical care.

  2. Towards clinical evidence in particle therapy: ENLIGHT, PARTNER, ULICE and beyond

    CERN Document Server

    Combs, Stephanie E; Pötter, Richad; Orrechia, Roberto; Haberer, Thomas; Durante, Marco; Fossati, Piero; Parodi, Katia; Balosso, Jacques; Amaldi, Ugo; Baumann, Michael; Debus, Jürgen

    2013-01-01

    Since the middle of the 20th century, particle therapy has been in focus for patient treatments. In 1946, Robert Wilson proposed the use of charged particles for tumor therapy, and since then, the clinical use of protons and heavier ions, mainly carbon ions, has become more widespread. The first clinical evidence was obtained in Berkeley, treating radiation-resistant targets with various ion species. The main advantage of particle beams derive from their physical properties: through an inverted dose profile, regions within the entry channel of the beam can be spared of dose, while a steep dose deposition can be directed in an energydependent manner into the defined treatment volume (Bragg Peak). The following dose fall-off spares tissue behind the target volume, thus reducing integral dose significantly compared to when using photons. Heavier charged particles, such as carbon ions or oxygen, are additionally associated with an increased relative biological effectiveness (RBE), while the RBE of protons is comm...

  3. Interpretation of proton relative biological effectiveness using lesion induction, lesion repair, and cellular dose distribution

    International Nuclear Information System (INIS)

    Paganetti, H.

    2005-01-01

    Phenomenological biophysical models have been successfully used to estimate the relative biological effectiveness (RBE) of ions. The predictive power of these models is limited because they require measured dose-response data that are not necessarily available for all clinically relevant end points. Furthermore, input parameters often lack mechanistic interpretation. In order to link RBE to more fundamental biological parameters we combine the concepts of two well-established biophysical models, i.e., the phenomenological 'track structure' model and the more mechanistic 'lethal lesion/potentially lethal lesion' (LPL) model. We parametrize a relation between RBE, dose homogeneity in the cell nucleus and induction rates for different lesion types. The macroscopic dose-response relationship is described in the LPL model and the microscopic, subcellular, relationship is determined by the local dose deposition pattern. The formalism provides a framework for a mechanistic interpretation of RBE values

  4. Fifteen symposia on microdosimetry: implications for modern particle-beam cancer radiotherapy

    CERN Document Server

    Wambersie, A; Gueulette, J; Pihet, P

    2015-01-01

    The objective of microdosimetry was, and still is, to identify physical descriptions of the initial physical processes of ionising radiation interacting with biological matter which correlate with observed radiobiological effects with a view to improve the understanding of radiobiological mechanisms and effects. The introduction of therapy with particles starting with fast neutrons followed by negative pions, protons and light ions necessitated the application of biological weighting factors for absorbed dose in order to account for differences of the relative biological effectiveness (RBE). Dedicated radiobiological experiments in therapy beams with mammalian cells and with laboratory animals provided sets of RBE values which are used to evaluate empirical ‘clinical RBE values’. The combination of such experiments with microdosimetric measurements in identical conditions offered the possibility to establish semi-empirical relationships between microdosimetric parameters and results of RBE studies.

  5. The Mayo Clinic Value Creation System.

    Science.gov (United States)

    Swensen, Stephen J; Dilling, James A; Harper, C Michel; Noseworthy, John H

    2012-01-01

    The authors present Mayo Clinic's Value Creation System, a coherent systems engineering approach to delivering a single high-value practice. There are 4 tightly linked, interdependent phases of the system: alignment, discovery, managed diffusion, and measurement. The methodology is described and examples of the results to date are presented. The Value Creation System has been demonstrated to improve the quality of patient care while reducing costs and increasing productivity.

  6. Microdosimetric Characteristics of the Clinical Proton Beams at the JINR Phasotron, Dubna

    CERN Document Server

    Vlcek, B; Spurny, F

    2002-01-01

    The contribution of the high LET particles to dosimetric and microdosimetric characteristics of 150 and 205 MeV clinical proton beams was experimentally studied using track etched detectors. Secondary heavy charged particles produced from nuclear interactions and degraded protons at the Bragg peak region are particles with high LET. The method of the LET spectra measurement with track etched detectors allows one to determine the contribution of high LET particles to dosimetric characteristics of clinical proton beams: absorbed dose, equivalent dose and the value of the Relative Biological Effectiveness (RBE). Track detectors were irradiated in the various depth of clinical proton beams with the primary energies of 150 and 205 MeV. The LET spectra between 10 and 700 keV/m were measured by means of CR-39 track etched detectors and the automatic optical image analyzer LUCIA-II. The relative contribution of the high LET particles to absorbed dose increases from several per cent at the beam entrance to several ten...

  7. Low LET protons focused to submicrometer shows enhanced radiobiological effectiveness

    International Nuclear Information System (INIS)

    Schmid, T E; Zlobinskaya, O; Michalski, D; Molls, M; Multhoff, G; Greubel, C; Hable, V; Girst, S; Siebenwirth, C; Dollinger, G; Schmid, E

    2012-01-01

    This study shows that enhanced radiobiological effectiveness (RBE) values can be generated focusing low linear energy transfer (LET) radiation and thus changing the microdose distribution. 20 MeV protons (LET = 2.65 keV µm −1 ) are focused to submicrometer diameter at the ion microprobe superconducting nanoprobe for applied nuclear (Kern) physics experiments of the Munich tandem accelerator. The RBE values, as determined by measuring micronuclei (RBE MN = 1.48 ± 0.07) and dicentrics (RBE D = 1.92 ± 0.15), in human–hamster hybrid (A L ) cells are significantly higher when 117 protons were focused to a submicrometer irradiation field within a 5.4 × 5.4 µm 2 matrix compared to quasi homogeneous in a 1 × 1 µm 2 matrix applied protons (RBE MN = 1.28 ± 0.07; RBE D = 1.41 ± 0.14) at the same average dose of 1.7 Gy. The RBE values are normalized to standard 70 kV (dicentrics) or 200 kV (micronuclei) x-ray irradiation. The 117 protons applied per point deposit the same amount of energy like a 12 C ion with 55 MeV total energy (4.48 MeV u −1 ). The enhancements are about half of that obtained for 12 C ions (RBE MN = 2.20 ± 0.06 and RBE D = 3.21 ± 0.10) and they are attributed to intertrack interactions of the induced damages. The measured RBE values show differences from predictions of the local effect model (LEM III) that is used to calculate RBE values for irradiation plans to treat tumors with high LET particles. (paper)

  8. Patients' Values in Clinical Decision-Making.

    Science.gov (United States)

    Faggion, Clovis Mariano; Pachur, Thorsten; Giannakopoulos, Nikolaos Nikitas

    2017-09-01

    Shared decision-making involves the participation of patient and dental practitioner. Well-informed decision-making requires that both parties understand important concepts that may influence the decision. This fourth article in a series of 4 aims to discuss the importance of patients' values when a clinical decision is made. We report on how to incorporate important concepts for well-informed, shared decision-making. Here, we present patient values as an important issue, in addition to previously established topics such as the risk of bias of a study, cost-effectiveness of treatment approaches, and a comparison of therapeutic benefit with potential side effects. We provide 2 clinical examples and suggestions for a decision tree, based on the available evidence. The information reported in this article may improve the relationship between patient and dental practitioner, resulting in more well-informed clinical decisions. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The effect of energy spectrum change on DNA damage in and out of field in 10-MV clinical photon beams.

    Science.gov (United States)

    Ezzati, A O; Xiao, Y; Sohrabpour, M; Studenski, M T

    2015-01-01

    The aim of this study was to quantify the DNA damage induced in a clinical megavoltage photon beam at various depths in and out of the field. MCNPX was used to simulate 10 × 10 and 20 × 20 cm(2) 10-MV photon beams from a clinical linear accelerator. Photon and electron spectra were collected in a water phantom at depths of 2.5, 12.5 and 22.5 cm on the central axis and at off-axis points out to 10 cm. These spectra were used as an input to a validated microdosimetric Monte Carlo code, MCDS, to calculate the RBE of induced DSB in DNA at points in and out of the primary radiation field at three depths. There was an observable difference in the energy spectra for photons and electrons for points in the primary radiation field and those points out of field. In the out-of-field region, the mean energy for the photon and electron spectra decreased by a factor of about six and three from the in-field mean energy, respectively. Despite the differences in spectra and mean energy, the change in RBE was photon and electron spectra, these changes do not correlate with a change in RBE in a clinical MV photon beam as the electron spectra are dominated by electrons with energies >20 keV.

  10. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jufang, E-mail: jufangwang@impcas.ac.c [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China); Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China)

    2010-09-15

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV {mu}m{sup -1}) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV {mu}m{sup -1}. The mutation cross section saturated when LET was higher than 58.2 keV {mu}m{sup -1}. Meanwhile, the highest RBE{sub i} for inactivation located at 120.0 keV {mu}m{sup -1} and the highest RBE{sub m} for mutation was at 58.2 keV {mu}m{sup -1}. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  11. RBE [relative biological effectiveness] of tritium beta radiation to gamma radiation and x-rays analyzed by both molecular and genetic methods

    International Nuclear Information System (INIS)

    Lee, W.R.

    1988-01-01

    The relative biological effectiveness (RBE) of tritium beta radiation to 60 Co gamma radiation was determined using sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa as the biological effect. The SLRL test, a measure of mutations induced in germ cells transmitted through successive generations, yields a linear dose-response curve in the range used in these experiments. From these ratios of the slopes of the 3 H beta and the 60 Co gamma radiation linear dose response curves, an RBE of 2.7 is observed. When sources of error are considered, this observation suggests that the tritium beta particle is 2.7 ± 0.3 times more effective per unit of energy absorbed in inducing gene mutations transmitted to successive generation than 60 Co gamma radiation. Ion tracks with a high density of ions (high LET) are more efficient than tracks with a low ion density (low LET) in inducing transmissible mutations, suggesting interaction among products of ionization. Molecular analysis of x-ray induced mutations shows that most mutations are deletions ranging from a few base pairs as determined from sequence data to multi locus deletions as determined from complementation tests and Southern blots. 14 refs., 1 fig

  12. Consistency between Self-Reported and Recorded Values for Clinical Measures

    OpenAIRE

    III, Joseph Thomas; Paulet, Mindy; Rajpura, Jigar R.

    2016-01-01

    Objectives. This study evaluated consistency between self-reported values for clinical measures and recorded clinical measures. Methods. Self-reported values were collected for the clinical measures: systolic blood pressure, diastolic blood pressure, glucose level, height, weight, and cholesterol from health risk assessments completed by enrollees in a privately insured cohort. Body mass index (BMI) was computed from reported height and weight. Practitioner recorded values for the clinical me...

  13. Algorithms for the optimization of RBE-weighted dose in particle therapy.

    Science.gov (United States)

    Horcicka, M; Meyer, C; Buschbacher, A; Durante, M; Krämer, M

    2013-01-21

    We report on various algorithms used for the nonlinear optimization of RBE-weighted dose in particle therapy. Concerning the dose calculation carbon ions are considered and biological effects are calculated by the Local Effect Model. Taking biological effects fully into account requires iterative methods to solve the optimization problem. We implemented several additional algorithms into GSI's treatment planning system TRiP98, like the BFGS-algorithm and the method of conjugated gradients, in order to investigate their computational performance. We modified textbook iteration procedures to improve the convergence speed. The performance of the algorithms is presented by convergence in terms of iterations and computation time. We found that the Fletcher-Reeves variant of the method of conjugated gradients is the algorithm with the best computational performance. With this algorithm we could speed up computation times by a factor of 4 compared to the method of steepest descent, which was used before. With our new methods it is possible to optimize complex treatment plans in a few minutes leading to good dose distributions. At the end we discuss future goals concerning dose optimization issues in particle therapy which might benefit from fast optimization solvers.

  14. Study of the Clinical Proton Beam Relative Biological Effectiveness at the JINR Phasotron, Dubna

    CERN Document Server

    Vitanova, A; Gaevskii, V N; Molokonov, A G; Spurny, F; Fadeeva, T A; Shmakova, N L

    2002-01-01

    Proton clinical beams contain particles with high linear energy transfer (LET). Secondary heavy charged particles produced from nuclear interactions and degraded protons at the Bragg peak region are particles with high LET. These particles could enhance the Relative Biological Effectiveness (RBE) of the proton beam. We have carried out two radiobiological experiments to investigate the RBE of 150 MeV clinical proton beam. The irradiation of the Chinese Hamster V79 cells were performed at two points of the depth-dose distribution - at the beam entrance and at the Bragg peak. The contribution of the high LET particles to dosimetric and microdosimetric characteristics in the various depth of proton beam was also experimentally studied using the CR-39 track etched detectors. The LET spectra between 10 and 700 keV/{\\mu}m were measured by means of track detectors and the automatic optical image analyzer LUCIA-II. The relative contribution of the high LET particles to ab! sorbed dose increases from several per cent ...

  15. Enhanced neoplastic transformation by mammography X rays relative to 200 kVp X rays: indication for a strong dependence on photon energy of the RBE(M) for various end points.

    Science.gov (United States)

    Frankenberg, D; Kelnhofer, K; Bär, K; Frankenberg-Schwager, M

    2002-01-01

    The fundamental assumption implicit in the use of the atomic bomb survivor data to derive risk estimates is that the gamma rays of Hiroshima and Nagasaki are considered to have biological efficiencies equal to those of other low-LET radiations up to 10 keV/microm, including mammography X rays. Microdosimetric and radiobiological data contradict this assumption. It is therefore of scientific and public interest to evaluate the efficiency of mammography X rays (25-30 kVp) to induce cancer. In this study, the efficiency of mammography X rays relative to 200 kVp X rays to induce neoplastic cell transformation was evaluated using cells of a human hybrid cell line (CGL1). For both radiations, a linear-quadratic dose-effect relationship was observed for neoplastic transformation of CGL1 cells; there was a strong linear component for the 29 kVp X rays. The RBE(M) of mammography X rays relative to 200 kVp X rays was determined to be about 4 for doses energies of transformation of CGL1 cells. Both the data available in the literature and the results of the present study strongly suggest an increase of RBE(M) for carcinogenesis in animals, neoplastic cell transformation, and clastogenic effects with decreasing photon energy or increasing LET to an RBE(M) approximately 8 for mammography X rays relative to 60Co gamma rays.

  16. The social value of clinical research.

    Science.gov (United States)

    Habets, Michelle G J L; van Delden, Johannes J M; Bredenoord, Annelien L

    2014-09-05

    International documents on ethical conduct in clinical research have in common the principle that potential harms to research participants must be proportional to anticipated benefits. The anticipated benefits that can justify human research consist of direct benefits to the research participant, and societal benefits, also called social value. In first-in-human research, no direct benefits are expected and the benefit component of the risks-benefit assessment thus merely exists in social value. The concept social value is ambiguous by nature and is used in numerous ways in the research ethics literature. Because social value justifies involving human participants, especially in early human trials, this is problematic. Our analysis and interpretation of the concept social value has led to three proposals. First, as no direct benefits are expected for the research participants in first-in-human trials, we believe it is better to discuss a risk- value assessment instead of a risk - benefit assessment. This will also make explicit the necessity to have a clear and common use for the concept social value. Second, to avoid confusion we propose to limit the concept social value to the intervention tested. It is the expected improvement the intervention can bring to the wellbeing of (future) patients or society that is referred to when we speak about social value. For the sole purpose of gaining knowledge, we should not expose humans to potential harm; the ultimate justification of involving humans in research lies in the anticipated social value of the intervention. Third, at the moment only the validity of the clinical research proposal is a prerequisite for research to take place. We recommend making the anticipated social value a prerequisite as well. In this paper we analyze the use of the concept social value in research ethics. Despite its unavoidable ambiguity, we aim to find a best use of the concept, subject to its role in justifying involving humans in first

  17. The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy

    CERN Document Server

    Mairani, A; Kraemer, M; Sommerer, F; Parodi, K; Scholz, M; Cerutti, F; Ferrari, A; Fasso, A

    2010-01-01

    Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fur Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed C-12 ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-d...

  18. In Defense of a Social Value Requirement for Clinical Research.

    Science.gov (United States)

    Wendler, David; Rid, Annette

    2017-02-01

    Many guidelines and commentators endorse the view that clinical research is ethically acceptable only when it has social value, in the sense of collecting data which might be used to improve health. A version of this social value requirement is included in the Declaration of Helsinki and the Nuremberg Code, and is codified in many national research regulations. At the same time, there have been no systematic analyses of why social value is an ethical requirement for clinical research. Recognizing this gap in the literature, recent articles by Alan Wertheimer and David Resnik argue that the extant justifications for the social value requirement are unpersuasive. Both authors conclude, contrary to almost all current guidelines and regulations, that it can be acceptable across a broad range of cases to conduct clinical research which is known prospectively to have no social value. The present article assesses this conclusion by critically evaluating the ethical and policy considerations relevant to the claim that clinical research must have social value. This analysis supports the standard view that social value is an ethical requirement for the vast majority of clinical research studies and should be mandated by applicable guidelines and policies. © 2017 John Wiley & Sons Ltd.

  19. Determination of Relative Biological Efficacy (RBE) and Oxygen Enhancement Ratio (OER) for the entire negative and positive pion beam profile using Vicia faba roots and Drosophila embryos as biological model systems

    International Nuclear Information System (INIS)

    Baarli, J.; Bianchi, M.; Keusch, F.; Mindek, G.; Sullivan, A.H.

    As an introduction to preclinical studies, pilot studies of pion beams are planned with relatively simple biological model systems that can be quickly evaluated and that yield indicative data for further action. Inhibition of growth was studied in Vicia faba roots, a biological system excellently suited for RBE and OER studies. For comparison there are already results from a low-intensity pion irradiation. A second system used Drosophila embryos 1 and 4 hours old, which are especially well suited for LET studies. The unambiguous criterion will be failure to slip out of the oolemma. The smallness of the objects (their beam sensitivity) will make it possible to determine empirically the peak region and to determine Gain factors; furthermore, the known dependency of RBE on the development stage promises highly informative results

  20. 7th Workshop on heavy charged particles in biology and medicine. Book of abstracts

    International Nuclear Information System (INIS)

    Kraft, G.; Langbein, K.

    2000-09-01

    The topics of the workshop were as follows: RBE experiments, reference data for treatment planning, RBE models, integration of RBE into treatment planning, clinical results. All papers are available as separate moduls in this database. (MG)

  1. value-sensitive clinical accompaniment in community nursing science

    African Journals Online (AJOL)

    2010-11-05

    Nov 5, 2010 ... negative effects on clinical learning in community nursing science. The goal of this ..... such positive effect of value-sensitive communication during clinical .... computer games the whole morning; it was unpleasant);. 'Ons [die ...

  2. Radiobiological evaluation of the suitability of negative pions in tumor therapy

    International Nuclear Information System (INIS)

    Fritz-Niggli, H.

    1979-01-01

    With the biomedical pion channel of the 590 MeV proton-accelerator of the Swiss Institute for Nuclear Research (SIN) for to test some theoretical conceptions in comparison to several preliminary experiments performed with pions of low dose rate. The dosimetric measurements showed an excellent depth curve with, e.g., a peak/plateau ratio of 2.5, for the momentum of 180 MeV/c and a ratio e - /π - of 0.1. The following systems have been used: Inactivation of single mammalian cells, induction of chromatid aberrations in Chinese hamster cells; small intestine of mouse (early and late effects); early and late effects in the mouse foot; induction of anomalies in mouse embryos; induction of cerebral microvascular damage in neonate rats; proliferation of Ehrlich-ascites carcinoma cells; induction of different types of mutation in different stages of male germ cells and somatic cells (Drosophila). The RBE-values in the peak region vary between 0,7-3.3, and are different even within the same system with the same end point but at different cell stages and conditions. For the plateau region the RBE-values lie mostly under 1 (compared with 140 kV-photons) and can be identical with 29 MeV-photons. The clinically important peak/plateau relation lies over 1 in every experiment and reaches even the value of 4.2. The unexpected RBE-values in peak under 1 lead to a new conception of RBE, the two system theory. In intrinsically radiosensitive euoxic systems (healthy tissue) the RBE of peak (star) pions can be under 1, in intrinsically radioresistant hypoxic systems (tumor cells) over 1. The two systems can also have different vulnerabilities of these repair systems. (orig./MG) 891 MG/orig.- 892 CKA [de

  3. TU-AB-BRC-02: Accuracy Evaluation of GPU-Based OpenCL Carbon Monte Carlo Package (goCMC) in Biological Dose and Microdosimetry in Comparison to FLUKA Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Taleei, R; Peeler, C; Qin, N; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: One of the most accurate methods for radiation transport is Monte Carlo (MC) simulation. Long computation time prevents its wide applications in clinic. We have recently developed a fast MC code for carbon ion therapy called GPU-based OpenCL Carbon Monte Carlo (goCMC) and its accuracy in physical dose has been established. Since radiobiology is an indispensible aspect of carbon ion therapy, this study evaluates accuracy of goCMC in biological dose and microdosimetry by benchmarking it with FLUKA. Methods: We performed simulations of a carbon pencil beam with 150, 300 and 450 MeV/u in a homogeneous water phantom using goCMC and FLUKA. Dose and energy spectra for primary and secondary ions on the central beam axis were recorded. Repair-misrepair-fixation model was employed to calculate Relative Biological Effectiveness (RBE). Monte Carlo Damage Simulation (MCDS) tool was used to calculate microdosimetry parameters. Results: Physical dose differences on the central axis were <1.6% of the maximum value. Before the Bragg peak, differences in RBE and RBE-weighted dose were <2% and <1%. At the Bragg peak, the differences were 12.5% caused by small range discrepancy and sensitivity of RBE to beam spectra. Consequently, RBE-weighted dose difference was 11%. Beyond the peak, RBE differences were <20% and primarily caused by differences in the Helium-4 spectrum. However, the RBE-weighted dose agreed within 1% due to the low physical dose. Differences in microdosimetric quantities were small except at the Bragg peak. The simulation time per source particle with FLUKA was 0.08 sec, while goCMC was approximately 1000 times faster. Conclusion: Physical doses computed by FLUKA and goCMC were in good agreement. Although relatively large RBE differences were observed at and beyond the Bragg peak, the RBE-weighted dose differences were considered to be acceptable.

  4. Spot-Scanning Proton Radiation Therapy for Pediatric Chordoma and Chondrosarcoma: Clinical Outcome of 26 Patients Treated at Paul Scherrer Institute

    Energy Technology Data Exchange (ETDEWEB)

    Rombi, Barbara [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); ATreP (Provincial Agency for Proton Therapy), Trento (Italy); Ares, Carmen, E-mail: carmen.ares@psi.ch [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Hug, Eugen B. [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); ProCure Proton Therapy Center, Somerset, New Jersey (United States); Schneider, Ralf; Goitein, Gudrun; Staab, Adrian; Albertini, Francesca; Bolsi, Alessandra; Lomax, Antony J. [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Timmermann, Beate [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); WestGerman Proton Therapy Center Essen (Germany)

    2013-07-01

    Purpose: To evaluate the clinical results of fractionated spot-scanning proton radiation therapy (PT) in 26 pediatric patients treated at Paul Scherrer Institute for chordoma (CH) or chondrosarcoma (CS) of the skull base or axial skeleton. Methods and Materials: Between June 2000 and June 2010, 19 CH and 7 CS patients with tumors originating from the skull base (17) and the axial skeleton (9) were treated with PT. Mean age at the time of PT was 13.2 years. The mean prescribed dose was 74 Gy (relative biological effectiveness [RBE]) for CH and 66 Gy (RBE) for CS, at a dose of 1.8-2.0 Gy (RBE) per fraction. Results: Mean follow-up was 46 months. Actuarial 5-year local control (LC) rates were 81% for CH and 80% for CS. Actuarial 5-year overall survival (OS) was 89% for CH and 75% for CS. Two CH patients had local failures: one is alive with evidence of disease, while the other patient succumbed to local recurrence in the surgical pathway. One CS patient died of local progression of the disease. No high-grade late toxicities were observed. Conclusions: Spot-scanning PT for pediatric CH and CS patients resulted in excellent clinical outcomes with acceptable rates of late toxicity. Longer follow-up time and larger cohort are needed to fully assess tumor control and late effects of treatment.

  5. Optimizing value utilizing Toyota Kata methodology in a multidisciplinary clinic.

    Science.gov (United States)

    Merguerian, Paul A; Grady, Richard; Waldhausen, John; Libby, Arlene; Murphy, Whitney; Melzer, Lilah; Avansino, Jeffrey

    2015-08-01

    Value in healthcare is measured in terms of patient outcomes achieved per dollar expended. Outcomes and cost must be measured at the patient level to optimize value. Multidisciplinary clinics have been shown to be effective in providing coordinated and comprehensive care with improved outcomes, yet tend to have higher cost than typical clinics. We sought to lower individual patient cost and optimize value in a pediatric multidisciplinary reconstructive pelvic medicine (RPM) clinic. The RPM clinic is a multidisciplinary clinic that takes care of patients with anomalies of the pelvic organs. The specialties involved include Urology, General Surgery, Gynecology, and Gastroenterology/Motility. From May 2012 to November 2014 we performed time-driven activity-based costing (TDABC) analysis by measuring provider time for each step in the patient flow. Using observed time and the estimated hourly cost of each of the providers we calculated the final cost at the individual patient level, targeting clinic preparation. We utilized Toyota Kata methodology to enhance operational efficiency in an effort to optimize value. Variables measured included cost, time to perform a task, number of patients seen in clinic, percent value-added time (VAT) to patients (face to face time) and family experience scores (FES). At the beginning of the study period, clinic costs were $619 per patient. We reduced conference time from 6 min/patient to 1 min per patient, physician preparation time from 8 min to 6 min and increased Medical Assistant (MA) preparation time from 9.5 min to 20 min, achieving a cost reduction of 41% to $366 per patient. Continued improvements further reduced the MA preparation time to 14 min and the MD preparation time to 5 min with a further cost reduction to $194 (69%) (Figure). During this study period, we increased the number of appointments per clinic. We demonstrated sustained improvement in FES with regards to the families overall experience with their providers

  6. To the radiotoxicity of {sup 99m}Tc radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Ftacnikova, S [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

    1996-12-31

    In this paper the radiotoxicity and RBE values of Auger electrons for {sup 99m}Tc radiopharmaceuticals were discussed. Expression for the expected RBE for {sup 99m}Tc compounds is given. For the Auger electrons emitted in the decay of {sup 99m}Tc the RBE(Auger) = 10 and a value of 20 for the radiation weighing factor were recommended. (J.K.) 4 refs.

  7. A treatment planning comparison of BPA- or BSH-based BNCT of malignant gliomas

    International Nuclear Information System (INIS)

    Capala, J.; Coderre, J.A.; Chanana, A.D.

    1996-01-01

    Accurate delivery of the prescribed dose during clinical BNCT requires knowledge (or reasonably valid assumptions) about the boron concentrations in tumor and normal tissues. For conversion of physical dose (Gy) into photon-equivalent dose (Gy-Eq), relative biological effectiveness (RBE) and/or compound-adjusted biological effectiveness (CBE) factors are required for each tissue. The BNCT treatment planning software requires input of the following values: the boron concentration in blood and tumor, RBEs in brain, tumor and skin for the high-LET beam components, the CBE factors for brain, tumor, and skin, and the RBE for the gamma component

  8. Ecodosimetry weighting factor (eR) for non-human biota

    International Nuclear Information System (INIS)

    Trivedi, A.; Gentner, N.E.

    2000-01-01

    The ICRP's radiological protection guidance for humans recognizes that equal absorbed doses of different types of radiation can have different biological effects in humans. ICRP publication 60 thus prescribes radiation weighting factors, w R values, to modify the absorbed dose (Gy) to effective dose (Sv) to enable the risk from different types of radiation to be compared on an equivalent basis. The w R values are selected on the basis of various considerations, including the linear energy transfer of the radiation and relative biological effectiveness (RBE) values (which are the ratios of the absorbed dose of reference to test radiation that produce an equivalent level of effect, for a given endpoint, system and dose level). There is no similar factor for non-human biota. It would be useful to have one: assessment of possible impacts on non-human biota (particularly from alpha-emitters and tritium beta-rays) is important for Canadian nuclear facilities. We propose a radiation equivalency factor 'e R ' for biota to fulfill a role equivalent to that occupied by w R in human radiation protection. RBE values for deterministic effects such as reproduction, fecundity and survival in biota are the critical bases for selection of e R values. These deterministic effects in populations are far more relevant to the assessment endpoints in ecological risk assessment than are stochastic effects, to which RBE values in human radiation protection relate. For tritium β-rays, most determinations support RBE values of 2-3 for deterministic effects when referenced to gamma radiation but little more than unity when x-rays are the reference radiation. This is because x-rays themselves have RBE -2 if referenced to gamma rays. Despite this, the ICRP assigns a w R of 1 to all electrons and all photons, including tritium beta-rays. Therefore, if e R is constrained to an integer, 1 is more appropriate than a value of 2 for tritium beta-rays. An RBE factor of 200-300 for alpha particles in

  9. 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

  10. Relative biological effectiveness in canine osteosarcoma cells irradiated with accelerated charged particles

    Science.gov (United States)

    Maeda, Junko; Cartwright, Ian M.; Haskins, Jeremy S.; Fujii, Yoshihiro; Fujisawa, Hiroshi; Hirakawa, Hirokazu; Uesaka, Mitsuru; Kitamura, Hisashi; Fujimori, Akira; Thamm, Douglas H.; Kato, Takamitsu A.

    2016-01-01

    Heavy ions, characterized by high linear energy transfer (LET) radiation, have advantages compared with low LET protons and photons in their biological effects. The application of heavy ions within veterinary clinics requires additional background information to determine heavy ion efficacy. In the present study, comparison of the cell-killing effects of photons, protons and heavy ions was investigated in canine osteosarcoma (OSA) cells in vitro. A total of four canine OSA cell lines with various radiosensitivities were irradiated with 137Cs gamma-rays, monoenergetic proton beams, 50 keV/µm carbon ion spread out Bragg peak beams and 200 keV/µm iron ion monoenergetic beams. Clonogenic survival was examined using colony-forming as says, and relative biological effectiveness (RBE) values were calculated relative to gamma-rays using the D10 value, which is determined as the dose (Gy) resulting in 10% survival. For proton irradiation, the RBE values for all four cell lines were 1.0–1.1. For all four cell lines, exposure to carbon ions yielded a decreased cell survival compared with gamma-rays, with the RBE values ranging from 1.56–2.10. Iron ions yielded the lowest cell survival among tested radiation types, with RBE values ranging from 3.51–3.69 observed in the three radioresistant cell lines. The radiosensitive cell line investigated demonstrated similar cell survival for carbon and iron ion irradiation. The results of the present study suggest that heavy ions are more effective for killing radioresistant canine OSA cells when compared with gamma-rays and protons. This markedly increased efficiency of cell killing is an attractive reason for utilizing heavy ions for radioresistant canine OSA. PMID:27446477

  11. Repair of potentially lethal radiation damage: comparison of neutron and x-ray RBE and implications for radiation therapy

    International Nuclear Information System (INIS)

    Hall, E.J.; Kraljevic, U.

    1976-01-01

    Experiments with Chinese hamster cells have shown that neutron irradiation does not result in repair of potentially lethal damage (PLD), i.e., that which can be influenced by changes in environmental conditions following irradiation. Since PLD is presumed to be repaired in tumors but not in normal tissues, this absence of differential sparing of tumor cells relative to normal tissues--a feature characteristic of irradiation with x rays--represents an advantage of neutrons in addition to their reduced oxygen effect. At a given dose, the difference in relative biological effectiveness (RBE) between tumors and normal tissues corresponds to a 5 percent increase in tumor dose with no concomitant increase in dose to normal tissues, which could be significant in cancer therapy

  12. Value-sensitive clinical accompaniment in community nursing science

    Directory of Open Access Journals (Sweden)

    Sonya Beukes

    2010-11-01

    The goal of this study was to explore and describe the experiences of students with regard to value-sensitive clinical accompaniment in the community nursing environment. An exploratory, descriptive and contextual design was used. Interactions between community nurses and students during clinical accompaniment were explored for value sensitivity by means of video recordings,participant observation and focus group interviews. Data were collected by means of video recordings, participant observation and focus group interviews. The data were analysed and coded by the researcher and the external coder, using an inductive descriptive method to identify important segments of the regularity of behaviour. The focus group interviews were transcribed, analysed and coded by the researcher and the external coder, using Tesch’s steps of analysis (Creswell 1994:155–156.Lincoln and Guba’s criteria (1985:290 for trustworthiness were applied to the study. The general findings indicate that clinical accompaniment in community nursing is not value sensitive and, as a result, guidelines for value-sensitive clinical accompaniment need to be developed for undergraduate students in the community nursing environment. The following values (values for which guidelines need to be developed were identified: respect during clinical accompaniment,value-sensitive communication and sensitivity to the quality of clinical accompaniment. Opsomming Kliniese gemeenskapsgesondheidsfasiliteite waar voorgraadse studente geplaas word vir gemeenskapsverpleegkundepraktika is dinamies en het groot veranderinge oor die laaste paar jare ondergaan. In die kliniese veld verteenwoordig gemeenskapsverpleegkundiges en voorgraadse studente verskillende rasse en taal- en etniese groepe in die Suid-Afrikaanse bevolking, elkeen met verskillende waardes. Albei partye – studente en gemeenskapsverpleegkundiges – het gerapporteer dat waardekonflik weens verskillende kulture en waardes tydens kliniese begeleiding

  13. SU-F-T-128: Dose-Volume Constraints for Particle Therapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R; Smith, W; Hendrickson, K; Meyer, J; Cao, N; Lee, E; Gopan, O; Sandison, G; Parvathaneni, U; Laramore, G [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: Determine equivalent Organ at Risk (OAR) tolerance dose (TD) constraints for MV x-rays and particle therapy. Methods: Equivalent TD estimates for MV x-rays are determined from an isoeffect, regression-analysis of published and in-house constraints for various fractionation schedules (n fractions). The analysis yields an estimate of (α/β) for an OAR. To determine equivalent particle therapy constraints, the MV x-ray TD(n) values are divided by the RBE for DSB induction (RBE{sub DSB}) or cell survival (RBE{sub S}). Estimates of (RBE{sub DSB}) are computed using the Monte Carlo Damage Simulation, and estimates of RBES are computed using the Repair-Misrepair-Fixation (RMF) model. A research build of the RayStation™ treatment planning system implementing the above model is used to estimate (RBE{sub DSB}) for OARs of interest in 16 proton therapy patient plans (head and neck, thorax, prostate and brain). Results: The analysis gives an (α/β) estimate of about 20 Gy for the trachea and heart and 2–4 Gy for the esophagus, spine, and brachial plexus. Extrapolation of MV x-ray constraints (n = 1) to fast neutrons using RBE{sub DSB} = 2.7 are in excellent agreement with clinical experience (n = 10 to 20). When conventional (n > 30) x-ray treatments are used as the reference radiation, fast neutron RBE increased to a maximum of 6. For comparison to a constant RBE of 1.1, the RayStation™ analysis gave estimates of proton RBE{sub DSB} from 1.03 to 1.33 for OARs of interest. Conclusion: The presented system of models is a convenient formalism to synthesize from multiple sources of information a set of self-consistent plan constraints for MV x-ray and hadron therapy treatments. Estimates of RBE{sub DSB} from the RayStation™ analysis differ substantially from 1.1 and vary among patients and treatment sites. A treatment planning system that incorporates patient and anatomy-specific corrections in proton RBE would create opportunities to increase the therapeutic

  14. Improving healthcare value through clinical community and supply chain collaboration.

    Science.gov (United States)

    Ishii, Lisa; Demski, Renee; Ken Lee, K H; Mustafa, Zishan; Frank, Steve; Wolisnky, Jean Paul; Cohen, David; Khanna, Jay; Ammerman, Joshua; Khanuja, Harpal S; Unger, Anthony S; Gould, Lois; Wachter, Patricia Ann; Stearns, Lauren; Werthman, Ronald; Pronovost, Peter

    2017-03-01

    We hypothesized that integrating supply chain with clinical communities would allow for clinician-led supply cost reduction and improved value in an academic health system. Three clinical communities (spine, joint, blood management) and one clinical community-like physician led team of surgeon stakeholders partnered with the supply chain team on specific supply cost initiatives. The teams reviewed their specific utilization and cost data, and the physicians led consensus-building conversations over a series of team meetings to agree to standard supply utilization. The spine and joint clinical communities each agreed upon a vendor capping model that led to cost savings of $3 million dollars and $1.5 million dollars respectively. The blood management decreased blood product utilization and achieved $1.2 million dollars savings. $5.6 million dollars in savings was achieved by a clinical community-like group of surgeon stakeholders through standardization of sutures and endomechanicals. Physician led clinical teams empowered to lead change achieved substantial supply chain cost savings in an academic health system. The model of combining clinical communities with supply chain offers hope for an effective, practical, and scalable approach to improving value and engaging physicians in other academic health systems. This clinician led model could benefit both private and academic health systems engaging in value optimization efforts. N/A. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. SU-F-T-124: Radiation Biological Equivalent Presentations OfLEM-1 and MKM Approaches in the Carbon-Ion Radiotherapy

    International Nuclear Information System (INIS)

    Hsi, W; Jiang, G; Sheng, Y

    2016-01-01

    Purpose: To study the correlations of the radiation biological equivalent doses (BED) along depth and lateral distance between LEM-1 and MKM approaches. Methods: In NIRS-MKM (Microdosimetric Kinetic Model) approach, the prescribed BED, referred as C-Eq, doses aims to present the relative biological effectiveness (RBE) for different energies of carbon-ions on a fixed 10% survival value of HCG cell with respect to convention X-ray. Instead of a fixed 10% survival, the BED doses of LEM-1 (Local Effect Model) approach, referred as X-Eq, aims to present the RBE over the whole survival curve of chordoma-like cell with alpha/beta ratio of 2.0. The relationship of physical doses as a function of C-Eq and X-Eq doses were investigated along depth and lateral distance for various sizes of cubic targets in water irradiated by carbon-ions. Results: At the center of each cubic target, the trends between physical and C-Eq or X-Eq doses can be described by a linear and 2nd order polynomial functions, respectively. Using fit functions can then calculate a scaling factor between C-Eq and X-Eq doses to have similar physical doses. With equalized C-Eq and X-Eq doses at the depth of target center, over- and under-estimated X-Eq to C-Eq are seen for depths before and after the target center, respectively. Near the distal edge along depth, sharp rising of RBE value is observed for X-Eq, but sharp dropping of RBE value is observed for C-Eq. For lateral locations near and just outside 50% dose level, sharp raising of RBE value is also seen for X-Eq, while only minor increasing with fast dropping for C-Eq. Conclusion: An analytical function to model the differences between the CEq and X-Eq doses along depth and lateral distance need to further investigated to explain varied clinic outcome of specific cancers using two different approaches to calculated BED doses.

  16. METHODS OF ASSESSMENT OF THE RELATIVE BIOLOGICAL EFFECTIVENESS OF NEUTRONS IN NEUTRON THERAPY

    Directory of Open Access Journals (Sweden)

    V. A. Lisin

    2017-01-01

    Full Text Available The relative biological effectiveness (RBE of fast neutrons is an important factor influencing the quality of neutron therapy therefore, the assessment of RBE is of great importance. Experimental and clinical studies as well as different mathematical and radiobiological models are used for assessing RBE. Research is conducted for neutron sources differing in the method of producing particles, energy and energy spectrum. Purpose: to find and analyze the dose-dependence of fast neutron RBE in neutron therapy using the U-120 cyclotron and NG-12I generator. Material and methods: The optimal method for assessing the relative biological effectiveness of neutrons for neutron therapy was described. To analyze the dependence of the RBE on neutron dose, the multi-target model of cell survival was applied. Results: The dependence of the RBE of neutrons produced from the U-120 cyclotron and NG-120 generator on the dose level was found for a single irradiation of biological objects. It was shown that the function of neutron dose was consistent with similar dependencies found by other authors in the experimental and clinical studies.

  17. Reformulation of a clinical-dose system for carbon-ion radiotherapy treatment planning at the National Institute of Radiological Sciences, Japan

    Science.gov (United States)

    Inaniwa, Taku; Kanematsu, Nobuyuki; Matsufuji, Naruhiro; Kanai, Tatsuaki; Shirai, Toshiyuki; Noda, Koji; Tsuji, Hiroshi; Kamada, Tadashi; Tsujii, Hirohiko

    2015-04-01

    At the National Institute of Radiological Sciences (NIRS), more than 8,000 patients have been treated for various tumors with carbon-ion (C-ion) radiotherapy in the past 20 years based on a radiobiologically defined clinical-dose system. Through clinical experience, including extensive dose escalation studies, optimum dose-fractionation protocols have been established for respective tumors, which may be considered as the standards in C-ion radiotherapy. Although the therapeutic appropriateness of the clinical-dose system has been widely demonstrated by clinical results, the system incorporates several oversimplifications such as dose-independent relative biological effectiveness (RBE), empirical nuclear fragmentation model, and use of dose-averaged linear energy transfer to represent the spectrum of particles. We took the opportunity to update the clinical-dose system at the time we started clinical treatment with pencil beam scanning, a new beam delivery method, in 2011. The requirements for the updated system were to correct the oversimplifications made in the original system, while harmonizing with the original system to maintain the established dose-fractionation protocols. In the updated system, the radiation quality of the therapeutic C-ion beam was derived with Monte Carlo simulations, and its biological effectiveness was predicted with a theoretical model. We selected the most used C-ion beam with αr = 0.764 Gy-1 and β = 0.0615 Gy-2 as reference radiation for RBE. The C-equivalent biological dose distribution is designed to allow the prescribed survival of tumor cells of the human salivary gland (HSG) in entire spread-out Bragg peak (SOBP) region, with consideration to the dose dependence of the RBE. This C-equivalent biological dose distribution is scaled to a clinical dose distribution to harmonize with our clinical experiences with C-ion radiotherapy. Treatment plans were made with the original and the updated clinical-dose systems, and both

  18. Personal values and self-esteem in general and clinical population

    Directory of Open Access Journals (Sweden)

    Vanesa C. Góngora

    2015-09-01

    Full Text Available The aim of this study is to investigate the association between personal values and self-esteem in general population and clinical population. The sample was composed of a group of patients with a diagnosis of anxiety disorders and/or depression (n = 60 and a comparison group, paired by sex and age, of general population (n = 60. The Portrait Values Questionnaire of Schwartz (PVQ and the Autoe Self-esteem Scale were used. T-tests were performed to compare the scores of both instruments between the two groups. The clinical sample scored significantly lower in Self-esteem, Self- direction, Hedonism, and Openness to Change. For this reason, Pearson correlations were calculated in differential groups (clinical and general between the PVQ and the Self-esteem Scale. In the general population group self-esteem was associated to one value: Self-direction. In the clinical group, self-esteem was associated mainly to Self- direction, but also to Hedonism, Power and Security; and to the axis Self-promotion and Openness to Change. Both in the clinical and general population samples it was found a significant association between the interest in having independent thought, freedom of action and exploring with higher levels of self-esteem. 

  19. Clinical outcomes and toxicity of proton beam therapy for advanced cholangiocarcinoma

    International Nuclear Information System (INIS)

    Makita, Chiyoko; Kikuchi, Yasuhiro; Hareyama, Masato; Murakami, Masao; Fuwa, Nobukazu; Hata, Masaharu; Inoue, Tomio; Nakamura, Tatsuya; Takada, Akinori; Takayama, Kanako; Suzuki, Motohisa; Ishikawa, Yojiro; Azami, Yusuke; Kato, Takahiro; Tsukiyama, Iwao

    2014-01-01

    We examined the efficacy and toxicity of proton beam therapy (PBT) for treating advanced cholangiocarcinoma. The clinical data and outcomes of 28 cholangiocarcinoma patients treated with PBT between January 2009 and August 2011 were retrospectively examined. The Kaplan–Meier method was used to estimate overall survival (OS), progression-free survival (PFS), and local control (LC) rates, and the log-rank test to analyze the effects of different clinical and treatment variables on survival. Acute and late toxicities were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. The median age of the 17 male and 11 female patients was 71 years (range, 41 to 84 years; intrahepatic/peripheral cholangiocarcinoma, n = 6; hilar cholangiocarcinoma/Klatskin tumor, n = 6; distal extrahepatic cholangiocarcinoma, n = 3; gallbladder cancer, n = 3; local or lymph node recurrence, n = 10; size, 20–175 mm; median 52 mm). The median radiation dose was 68.2 Gy (relative biological effectiveness [RBE]) (range, 50.6 to 80 Gy (RBE)), with delivery of fractions of 2.0 to 3.2 Gy (RBE) daily. The median follow-up duration was 12 months (range, 3 to 29 months). Fifteen patients underwent chemotherapy and 8 patients, palliative biliary stent placement prior to PBT. OS, PFS, and LC rates at 1 year were 49.0%, 29.5%, and 67.7%, respectively. LC was achieved in 6 patients, and was better in patients administered a biologically equivalent dose of 10 (BED10) > 70 Gy compared to those administered < 70 Gy (83.1% vs. 22.2%, respectively, at 1 year). The variables of tumor size and performance status were associated with survival. Late gastrointestinal toxicities grade 2 or greater were observed in 7 patients <12 months after PBT. Cholangitis was observed in 11 patients and 3 patients required stent replacement. Relatively high LC rates after PBT for advanced cholangiocarcinoma can be achieved by delivery of a BED10 > 70 Gy. Gastrointestinal

  20. Spot Scanning Proton Therapy for Malignancies of the Base of Skull: Treatment Planning, Acute Toxicities, and Preliminary Clinical Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhu, X. Ronald; Melancon, Adam [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Poenisch, Falk; Palmer, Matthew [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); McAleer, Mary Frances; McGovern, Susan L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gillin, Michael [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); DeMonte, Franco [Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Eric L. [Department of Radiation Oncology, University of Southern California Keck School of Medicine, Los Angeles, California (United States); Brown, Paul D.; Mahajan, Anita [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-11-01

    Purpose: To describe treatment planning techniques and early clinical outcomes in patients treated with spot scanning proton therapy for chordoma or chondrosarcoma of the skull base. Methods and Materials: From June 2010 through August 2011, 15 patients were treated with spot scanning proton therapy for chordoma (n=10) or chondrosarcoma (n=5) at a single institution. Toxicity was prospectively evaluated and scored weekly and at all follow-up visits according to Common Terminology Criteria for Adverse Events, version 3.0. Treatment planning techniques and dosimetric data were recorded and compared with those of passive scattering plans created with clinically applicable dose constraints. Results: Ten patients were treated with single-field-optimized scanning beam plans and 5 with multifield-optimized intensity modulated proton therapy. All but 2 patients received a simultaneous integrated boost as well. The mean prescribed radiation doses were 69.8 Gy (relative biological effectiveness [RBE]; range, 68-70 Gy [RBE]) for chordoma and 68.4 Gy (RBE) (range, 66-70) for chondrosarcoma. In comparison with passive scattering plans, spot scanning plans demonstrated improved high-dose conformality and sparing of temporal lobes and brainstem. Clinically, the most common acute toxicities included fatigue (grade 2 for 2 patients, grade 1 for 8 patients) and nausea (grade 2 for 2 patients, grade 1 for 6 patients). No toxicities of grades 3 to 5 were recorded. At a median follow-up time of 27 months (range, 13-42 months), 1 patient had experienced local recurrence and a second developed distant metastatic disease. Two patients had magnetic resonance imaging-documented temporal lobe changes, and a third patient developed facial numbness. No other subacute or late effects were recorded. Conclusions: In comparison to passive scattering, treatment plans for spot scanning proton therapy displayed improved high-dose conformality. Clinically, the treatment was well tolerated, and

  1. Clinical value of component-resolved diagnostics in peanut-allergic patients

    DEFF Research Database (Denmark)

    Eller, E; Bindslev-Jensen, C

    2013-01-01

    As replacement for the oral food challenge, decision-points for sensitization test have been established, but suboptimal sensitivity and/or specificity, as well as regional differences, have reduced the clinical usability. IgE toward specific peanut protein components has been reported to be of v......As replacement for the oral food challenge, decision-points for sensitization test have been established, but suboptimal sensitivity and/or specificity, as well as regional differences, have reduced the clinical usability. IgE toward specific peanut protein components has been reported...... to be of value, but data on correlation with clinical data are sparse. Our aim was to correlate IgE values with the outcome of peanut challenges....

  2. Specification of carbon ion dose at the National Institute of Radiological Sciences (NIRS)

    International Nuclear Information System (INIS)

    Matsufuji, Naruhiro; Nakai, Tatsuaki; Kanematsu, Nobuyuki

    2007-01-01

    The clinical dose distributions of therapeutic carbon beams, currently used at National Institute of Radiological Sciences (NIRS) Heavy Ion Medical Accelerator in Chiba (HIMAC), are based on in-vitro Human Salivary Gland (HSG) cell survival response and clinical experience from fast neutron radiotherapy. Moderate radiosensitivity of HSG cells is expected to be a typical response of tumours to carbon beams. At first, the biological dose distribution is designed so as to cause a flat biological effect on HSG cells in the spread-out Bragg peak (SOBP) region. Then, the entire biological dose distribution is evenly raised in order to attain a RBE (relative biological effectiveness)=3.0 at a depth where dose-averaged LET (linear energy transfer) is 80 keV/μm. At that point, biological experiments have shown that carbon ions can be expected to have a biological effect identical to fast neutrons, which showed a clinical RBE of 3.0 for fast neutron radiotherapy at NIRS. The resulting clinical dose distribution in this approximation is not dependent on dose level, tumour type or fractionation scheme and thus reduces the unknown parameters in the analysis of the clinical results. The width SOBP and the clinical/physical dose at the center of SOBP specify the dose distribution. The clinical results analyzed in terms of tumor control probability (TCP) were found to show good agreement with the expected RBE value at higher TCP levels. The TCP analysis method was applied for the prospective dose estimation of hypofractionation. (author)

  3. A phenomenological biological dose model for proton therapy based on linear energy transfer spectra.

    Science.gov (United States)

    Rørvik, Eivind; Thörnqvist, Sara; Stokkevåg, Camilla H; Dahle, Tordis J; Fjaera, Lars Fredrik; Ytre-Hauge, Kristian S

    2017-06-01

    The relative biological effectiveness (RBE) of protons varies with the radiation quality, quantified by the linear energy transfer (LET). Most phenomenological models employ a linear dependency of the dose-averaged LET (LET d ) to calculate the biological dose. However, several experiments have indicated a possible non-linear trend. Our aim was to investigate if biological dose models including non-linear LET dependencies should be considered, by introducing a LET spectrum based dose model. The RBE-LET relationship was investigated by fitting of polynomials from 1st to 5th degree to a database of 85 data points from aerobic in vitro experiments. We included both unweighted and weighted regression, the latter taking into account experimental uncertainties. Statistical testing was performed to decide whether higher degree polynomials provided better fits to the data as compared to lower degrees. The newly developed models were compared to three published LET d based models for a simulated spread out Bragg peak (SOBP) scenario. The statistical analysis of the weighted regression analysis favored a non-linear RBE-LET relationship, with the quartic polynomial found to best represent the experimental data (P = 0.010). The results of the unweighted regression analysis were on the borderline of statistical significance for non-linear functions (P = 0.053), and with the current database a linear dependency could not be rejected. For the SOBP scenario, the weighted non-linear model estimated a similar mean RBE value (1.14) compared to the three established models (1.13-1.17). The unweighted model calculated a considerably higher RBE value (1.22). The analysis indicated that non-linear models could give a better representation of the RBE-LET relationship. However, this is not decisive, as inclusion of the experimental uncertainties in the regression analysis had a significant impact on the determination and ranking of the models. As differences between the models were

  4. Effect of mentoring on professional values in model C clinical nurse leader graduates.

    Science.gov (United States)

    Gazaway, Shena B; Anderson, Lori; Schumacher, Autumn; Alichnie, Chris

    2018-04-19

    Nursing graduates acquire their nursing values by professional socialization. Mentoring is a crucial support mechanism for these novice nurses, yet little is known about the model C clinical nurse leader graduate and the effects of mentoring. This investigation examined how mentoring affected the development of professional nursing values in the model C clinical nurse leader graduate. A longitudinal design was used to survey model C clinical nurse leader graduates before and after graduation to determine how different types of mentoring relationships influenced professional values. Demographic surveys documented participant characteristics and the Nurses Professional Values Scale - Revised (NPVS-R) assessed professional nursing values. Mean NPVS-R scores increased after graduation for the formally mentored participants, while the NPVS-R scores decreased or remained unchanged for the other mentoring groups. However, no significant difference was found in NPVS-R scores over time (p = .092) or an interaction between the NPVS-R scores and type of mentoring relationships (p = .09). These results suggest that model C clinical nurse leader graduate participants experiencing formal mentoring may develop professional nursing values more than their colleagues. Formal mentoring relationships are powerful and should be used to promote professional values for model C clinical nurse leader graduates. © 2018 John Wiley & Sons Ltd.

  5. Impact of respiratory motion on variable relative biological effectiveness in 4D-dose distributions of proton therapy.

    Science.gov (United States)

    Ulrich, Silke; Wieser, Hans-Peter; Cao, Wenhua; Mohan, Radhe; Bangert, Mark

    2017-11-01

    Organ motion during radiation therapy with scanned protons leads to deviations between the planned and the delivered physical dose. Using a constant relative biological effectiveness (RBE) of 1.1 linearly maps these deviations into RBE-weighted dose. However, a constant value cannot account for potential nonlinear variations in RBE suggested by variable RBE models. Here, we study the impact of motion on recalculations of RBE-weighted dose distributions using a phenomenological variable RBE model. 4D-dose calculation including variable RBE was implemented in the open source treatment planning toolkit matRad. Four scenarios were compared for one field and two field proton treatments for a liver cancer patient assuming (α∕β) x  = 2 Gy and (α∕β) x  = 10 Gy: (A) the optimized static dose distribution with constant RBE, (B) a static recalculation with variable RBE, (C) a 4D-dose recalculation with constant RBE and (D) a 4D-dose recalculation with variable RBE. For (B) and (D), the variable RBE was calculated by the model proposed by McNamara. For (C), the physical dose was accumulated with direct dose mapping; for (D), dose-weighted radio-sensitivity parameters of the linear quadratic model were accumulated to model synergistic irradiation effects on RBE. Dose recalculation with variable RBE led to an elevated biological dose at the end of the proton field, while 4D-dose recalculation exhibited random deviations everywhere in the radiation field depending on the interplay of beam delivery and organ motion. For a single beam treatment assuming (α∕β) x  = 2 Gy, D 95 % was 1.98 Gy (RBE) (A), 2.15 Gy (RBE) (B), 1.81 Gy (RBE) (C) and 1.98 Gy (RBE) (D). The homogeneity index was 1.04 (A), 1.08 (B), 1.23 (C) and 1.25 (D). For the studied liver case, intrafractional motion did not reduce the modulation of the RBE-weighted dose postulated by variable RBE models for proton treatments.

  6. Medicine, methodology, and values: trade-offs in clinical science and practice.

    Science.gov (United States)

    Ho, Vincent K Y

    2011-01-01

    The current guidelines of evidence-based medicine (EBM) presuppose that clinical research and clinical practice should advance from rigorous scientific tests as they generate reliable, value-free knowledge. Under this presupposition, hypotheses postulated by doctors and patients in the process of their decision making are preferably tested in randomized clinical trials (RCTs), and in systematic reviews and meta-analyses summarizing outcomes from multiple RCTs. Since testing under this scheme is predominantly focused on the criteria of generality and precision achieved through methodological rigor, at the cost of the criterion of realism, translating test results to clinical practice is often problematic. Choices concerning which methodological criteria should have priority are inevitable, however, as clinical trials, and scientific research in general, cannot meet all relevant criteria at the same time. Since these choices may be informed by considerations external to science, we must acknowledge that science cannot be value-free in a strict sense, and this invites a more prominent role for value-laden considerations in evaluating clinical research. The urgency for this becomes even more apparent when we consider the important yet implicit role of scientific theories in EBM, which may also be subjected to methodological evaluation and for which selectiveness in methodological focus is likewise inevitable.

  7. The Emerging Business Models and Value Proposition of Mobile Health Clinics.

    Science.gov (United States)

    Aung, Khin-Kyemon; Hill, Caterina; Bennet, Jennifer; Song, Zirui; Oriol, Nancy E

    2015-12-01

    Mobile health clinics are increasingly used to deliver healthcare to urban and rural populations. An estimated 2000 vehicles in the United States are now delivering between 5 and 6 million visits annually; however, despite this growth, mobile health clinics represent an underutilized resource that could transform the way healthcare is delivered, especially in underserved areas. Preliminary research has shown that mobile health clinics have the potential to reduce costs and improve health outcomes. Their value lies primarily in their mobility, their ability to be flexibly deployed and customized to fit the evolving needs of populations and health systems, and their ability to link clinical and community settings. Few studies have identified how mobile health clinics can be sustainably utilized. We discuss the value proposition of mobile health clinics and propose 3 potential business models for them-adoption by accountable care organizations, payers, and employers.

  8. Synergistic interaction between the neutron and gamma radiation on LACA mice hemopoietic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H

    1982-02-01

    Based on the radiation action dual theory of DNA single and double strand breaks, a hypothetical RBE mathematical model for the effect of the mixed radiation of neutron and gamma rays on LACA mice hemopoietic stem cells was formulated. In comparison of the RBE values of different ratio of neutron and gamma-ray mixed radiation with their theoretical additive RBE values, the preliminary impression is that the mixed radiation is more effective than that of the theoretical additive effect. It seems that the existence of synergist in the mixed radiation might be valid.

  9. Spot Scanning and Passive Scattering Proton Therapy: Relative Biological Effectiveness and Oxygen Enhancement Ratio in Cultured Cells.

    Science.gov (United States)

    Iwata, Hiromitsu; Ogino, Hiroyuki; Hashimoto, Shingo; Yamada, Maho; Shibata, Hiroki; Yasui, Keisuke; Toshito, Toshiyuki; Omachi, Chihiro; Tatekawa, Kotoha; Manabe, Yoshihiko; Mizoe, Jun-etsu; Shibamoto, Yuta

    2016-05-01

    To determine the relative biological effectiveness (RBE), oxygen enhancement ratio (OER), and contribution of the indirect effect of spot scanning proton beams, passive scattering proton beams, or both in cultured cells in comparison with clinically used photons. The RBE of passive scattering proton beams at the center of the spread-out Bragg peak (SOBP) was determined from dose-survival curves in 4 cell lines using 6-MV X rays as controls. Survival of 2 cell lines after spot scanning and passive scattering proton irradiation was then compared. Biological effects at the distal end region of the SOBP were also investigated. The OER of passive scattering proton beams and 6 MX X rays were investigated in 2 cell lines. The RBE and OER values were estimated at a 10% cell survival level. The maximum degree of protection of radiation effects by dimethyl sulfoxide was determined to estimate the contribution of the indirect effect against DNA damage. All experiments comparing protons and X rays were made under the same biological conditions. The RBE values of passive scattering proton beams in the 4 cell lines examined were 1.01 to 1.22 (average, 1.14) and were almost identical to those of spot scanning beams. Biological effects increased at the distal end of the SOBP. In the 2 cell lines examined, the OER was 2.74 (95% confidence interval, 2.56-2.80) and 3.08 (2.84-3.11), respectively, for X rays, and 2.39 (2.38-2.43) and 2.72 (2.69-2.75), respectively, for protons (Pcells between X rays and protons). The maximum degree of protection was significantly higher for X rays than for proton beams (P<.05). The RBE values of spot scanning and passive scattering proton beams were almost identical. The OER was lower for protons than for X rays. The lower contribution of the indirect effect may partly account for the lower OER of protons. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. DWI of Prostate Cancer: Optimal b-Value in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Guglielmo Manenti

    2014-01-01

    Full Text Available Aim. To compare the diagnostic performance of diffusion weighted imaging (DWI using b-values of 1000 s/mm2 and 2000 s/mm2 at 3 Tesla (T for the evaluation of clinically significant prostate cancer. Matherials and Methods. Seventy-eight prostate cancer patients underwent a 3T MRI scan followed by radical prostatectomy. DWI was performed using b-values of 0, 1000, and 2000 s/mm2 and qualitatively analysed by two radiologists. ADC maps were obtained at b-values of 1000 and 2000 s/mm2 and quantitatively analyzed in consensus. Results. For diagnosis of 78 prostate cancers the accuracy of DWI for the young reader was significantly greater at b = 2000 s/mm2 for the peripheral zone (PZ but not for the transitional zone (TZ. For the experienced reader, DWI did not show significant differences in accuracy between b-values of 1000 and 2000 s/mm2. The quantitative analysis in the PZ and TZ was substantially superimposable between the two b-values, albeit with a higher accuracy with a b-value of 2000 s/mm2. Conclusions. With a b-value of 2000 s/mm2 at 3T both readers differentiated clinical significant cancer from benign tissue; higher b-values can be helpful for the less experienced readers.

  11. Proton Radiotherapy for Parameningeal Rhabdomyosarcoma: Clinical Outcomes and Late Effects

    Energy Technology Data Exchange (ETDEWEB)

    Childs, Stephanie K. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Kozak, Kevin R. [Department of Radiation Oncology, University of Wisconsin Cancer Center Johnson Creek, Madison, WI (United States); Friedmann, Alison M. [Department of Pediatric Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Yeap, Beow Y. [Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Adams, Judith; MacDonald, Shannon M.; Liebsch, Norbert J.; Tarbell, Nancy J. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

    2012-02-01

    Purpose: To report the clinical outcome and late side effect profile of proton radiotherapy in the treatment of children with parameningeal rhabdomyosarcoma (PM-RMS). Methods and Materials: Seventeen consecutive children with PM-RMS were treated with proton radiotherapy at Massachusetts General Hospital between 1996 and 2005. We reviewed the medical records of all patients and asked referring physicians to report specific side effects of interest. Results: Median patient age at diagnosis was 3.4 years (range, 0.4-17.6). Embryonal (n = 11), alveolar (n = 4), and undifferentiated (n = 2) histologies were represented. Ten patients (59%) had intracranial extension. Median prescribed dose was 50.4 cobalt gray equivalents (GyRBE) (range, 50.4-56.0 GyRBE) delivered in 1.8-2.0-GyRBE daily fractions. Median follow-up was 5.0 years for survivors. The 5-year failure-free survival estimate was 59% (95% confidence interval, 33-79%), and overall survival estimate was 64% (95% confidence interval, 37-82%). Among the 7 patients who failed, sites of first recurrence were local only (n = 2), regional only (n = 2), distant only (n = 2), and local and distant (n = 1). Late effects related to proton radiotherapy in the 10 recurrence-free patients (median follow-up, 5 years) include failure to maintain height velocity (n = 3), endocrinopathies (n = 2), mild facial hypoplasia (n = 7), failure of permanent tooth eruption (n = 3), dental caries (n = 5), and chronic nasal/sinus congestion (n = 2). Conclusions: Proton radiotherapy for patients with PM-RMS yields tumor control and survival comparable to that in historical controls with similar poor prognostic factors. Furthermore, rates of late effects from proton radiotherapy compare favorably to published reports of photon-treated cohorts.

  12. Quantification of Radiation-induced DNA Damage following intracellular Auger-Cascades

    DEFF Research Database (Denmark)

    Fredericia, Nina Pil Møntegaard

    2017-01-01

    Purpose: The aim my PhD study and the topic of this thesis is to investigate the radiotoxicity and the Relative Biological effectiveness (RBE) of intracellular Auger cascades. A special focus is kept on obtaining reliable absorbed dose calculations and using matched dose rate profiles for the Auger......-values (SC-values). The work can be divided into three steps; Examination of the bio-kinetics of the Auger emitter 131Cs used in the study, calculations of the SC-values and finally the measurement of the RBE of intracellular 131Cs decays, through ƴH2AX and clonogenic cell survival assay. Methods: A series....../(Bq*Sec)/pL for HeLa nuclei and from 7.45*10-4 to 7.63 *10-4 Gy/(Bq*Sec)/pL for V79 nuclei. The SC-values were shown to be were very robust and almost independent of cellular and nuclear size. A RBE value of 1 was obtained for HeLa cells using ƴH2AX assays. RBE values of 4.5 ± 0.5 and 3.8 ± 0.8 were obtained for He...

  13. From Value Assessment to Value Cocreation: Informing Clinical Decision-Making with Medical Claims Data.

    Science.gov (United States)

    Thompson, Steven; Varvel, Stephen; Sasinowski, Maciek; Burke, James P

    2016-09-01

    Big data and advances in analytical processes represent an opportunity for the healthcare industry to make better evidence-based decisions on the value generated by various tests, procedures, and interventions. Value-based reimbursement is the process of identifying and compensating healthcare providers based on whether their services improve quality of care without increasing cost of care or maintain quality of care while decreasing costs. In this article, we motivate and illustrate the potential opportunities for payers and providers to collaborate and evaluate the clinical and economic efficacy of different healthcare services. We conduct a case study of a firm that offers advanced biomarker and disease state management services for cardiovascular and cardiometabolic conditions. A value-based analysis that comprised a retrospective case/control cohort design was conducted, and claims data for over 7000 subjects who received these services were compared to a matched control cohort. Study subjects were commercial and Medicare Advantage enrollees with evidence of CHD, diabetes, or a related condition. Analysis of medical claims data showed a lower proportion of patients who received biomarker testing and disease state management services experienced a MI (p companies have in terms of identifying value-creating healthcare interventions. However, payers and providers also need to pursue system integration efforts to further automate the identification and dissemination of clinically and economically efficacious treatment plans to ensure at-risk patients receive the treatments and interventions that will benefit them the most.

  14. Reformulation of a clinical-dose system for carbon-ion radiotherapy treatment planning at the National Institute of Radiological Sciences, Japan

    International Nuclear Information System (INIS)

    Inaniwa, Taku; Kanematsu, Nobuyuki; Matsufuji, Naruhiro; Shirai, Toshiyuki; Noda, Koji; Kanai, Tatsuaki; Tsuji, Hiroshi; Kamada, Tadashi; Tsujii, Hirohiko

    2015-01-01

    At the National Institute of Radiological Sciences (NIRS), more than 8,000 patients have been treated for various tumors with carbon-ion (C-ion) radiotherapy in the past 20 years based on a radiobiologically defined clinical-dose system. Through clinical experience, including extensive dose escalation studies, optimum dose-fractionation protocols have been established for respective tumors, which may be considered as the standards in C-ion radiotherapy. Although the therapeutic appropriateness of the clinical-dose system has been widely demonstrated by clinical results, the system incorporates several oversimplifications such as dose-independent relative biological effectiveness (RBE), empirical nuclear fragmentation model, and use of dose-averaged linear energy transfer to represent the spectrum of particles. We took the opportunity to update the clinical-dose system at the time we started clinical treatment with pencil beam scanning, a new beam delivery method, in 2011. The requirements for the updated system were to correct the oversimplifications made in the original system, while harmonizing with the original system to maintain the established dose-fractionation protocols. In the updated system, the radiation quality of the therapeutic C-ion beam was derived with Monte Carlo simulations, and its biological effectiveness was predicted with a theoretical model. We selected the most used C-ion beam with α r = 0.764 Gy −1 and β = 0.0615 Gy −2 as reference radiation for RBE. The C-equivalent biological dose distribution is designed to allow the prescribed survival of tumor cells of the human salivary gland (HSG) in entire spread-out Bragg peak (SOBP) region, with consideration to the dose dependence of the RBE. This C-equivalent biological dose distribution is scaled to a clinical dose distribution to harmonize with our clinical experiences with C-ion radiotherapy. Treatment plans were made with the original and the updated clinical-dose systems, and both

  15. Beyond clinical utility: The multiple values of DTC genetics

    Directory of Open Access Journals (Sweden)

    Mauro Turrini

    2016-03-01

    Full Text Available One point of consensus in the otherwise very controversial discussion about the benefits and dangers of DTC genetics in the health domain is the lack of substantial clinical utility. At the same time, both the empirical and conceptual literature indicate that health-related DTC tests can have value and utility outside of the clinic. We argue that a broader and multi-faceted conceptualization of utility and value would enrich the ethical and social discussion of DTC testing in several ways: First, looking at ways in which DTC testing can have personal and social value for users – in the form of entertainment, learning, or a way to relate to others – can help to explain why people still take DTC tests, and will, further down the line, foster a more nuanced understanding of secondary and tertiary uses of DTC test results (which could very well unearth new ethical and regulatory challenges. Second, considering the economic value and broader utility of DTC testing foregrounds wider social and political aspects than have been dominant in the ethical and regulatory debates surrounding DTC genetics so far. These wider political aspects include the profound power asymmetries that characterize the collection and use of personal genetic data in many contexts.

  16. Effect of x rays and neutrons on repair and regeneration in the rat spinal cord

    International Nuclear Information System (INIS)

    van der Kogel, A.J.; Sissingh, H.A.; Zoetelief, J.

    1982-01-01

    Clinical and experimental results of neutron irradiation have shown higher RBE values for the central nervous system (CNS) than for most other normal tissues. This is because of a considerable impairment of a large capacity of the CNS to repair subeffective damage induced by low LET radiation. Decreasing the dose per fraction of X rays increases the CNS tolerance significantly; this has no effect for neutrons. In the cervical spinal cord and the brain, two types of delayed damage can be described, so-called early and late. Different target cells are assumed to be involved, oligodendroglial cells in the early, and vascular endothelim in the late type. In the lumbar cord, the main lesion is nerve root necrosis, with the Schwann cell as the most probable target. These target cells show differences in response to X rays and neutrons, resulting in different RBE values. The highest RBE is obtained for cervical white matter necrosis. In addition to cellular repair of subeffective damage, long-term tissue regeneration is observed in the spinal cord, beginning at different times for the various types of damage. With neutrons, the rate of long-term regeneration is at least similar, or even more pronounced than for X rays

  17. Effect of x rays and neutrons on repair and regeneration in the rat spinal cord

    International Nuclear Information System (INIS)

    Van der Kogel, A.J.; Sissingh, H.A.; Zoetelief, J.

    1982-01-01

    Clinical and experimental results of neutron irradiation have shown higher RBE values for the central nervous system (CNS) than for most other normal tissues. This is because of a considerable impairment of the large capacity of the CNS to repair subeffective damage induced by low LET radiation. Decreasing the dose per fraction of X rays increases the CNS tolerance significantly; this has no effect for neutrons. In the cervical spinal cord and the brain, two types of delayed damage can be described, so-called early and late. Different target cells are assumed to be involved, oligodendroglial cells in the early, and vascular endothelium in the late type. In the lumbar cord, the main lesion is nerve root necrosis, with the Schwann cell as the most probable target. These target cells show differences in response to X rays and neutrons, resulting in different RBE values. The highest RBE is obtained for cervical white matter necrosis. In addition to cellular repair of subeffective damage, long-term tissue regeneration is observed in the spinal cord, beginning at different times for the various types of damage. With neutrons, the rate of long-term regeneration is at least similar, or even more pronounced than for X rays

  18. A national survey on pediatric critical values used in clinical laboratories across Canada.

    Science.gov (United States)

    Gong, Yanping; Adeli, Khosrow

    2009-11-01

    Notification of critical values to clinical staff is an important post-analytical process in all acute care clinical laboratories. No data are available however on how laboratories obtain or establish critical values, particularly in pediatric settings. This study was designed to examine and compare critical values used for pediatric patients in biochemistry laboratories in Canada and assess potential interlaboratory variability. Fourteen clinical laboratories, including two in pediatric hospitals and twelve in hospitals caring for both children and adults, participated in a survey that included 14 pre-selected STAT chemistry tests and 19 pre-selected therapeutic drug monitoring (TDM) tests. Among fourteen chemistry tests, good agreement was observed for critical values used for sodium and pH at both low and high levels within 14 participant laboratories. Significant interlaboratory variability existed for glucose critical values at the high end, magnesium at high end, and PO2 at the low end. For 19 TDM tests, the majority of laboratories did not have alert values to report values over the therapeutic level but not toxic. For critical values greater than the toxic range, significant variability existed at both trough and peak levels among laboratories surveyed. When asked to provide the source for critical values established at each site, only a limited number of laboratories identified their sources as either internal decision or published references. Although all laboratories have established and routinely use critical values to alert clinical staff, considerable variability exists in both the critical limits reported as well as the source of such values. There is a clear need for new national efforts to standardize pediatric critical value reporting and establish evidence-based critical limits for all medical laboratories across Canada.

  19. A parameter study to determine the optimal source neutron energy in boron neutron capture therapy of brain tumours

    Energy Technology Data Exchange (ETDEWEB)

    Nievaart, V A [Reactor Physics Department, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands); Moss, R L [Joint Research Centre of the European Commission, Postbus 2, 1755ZG Petten (Netherlands); Kloosterman, J L [Reactor Physics Department, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands); Hagen, T H J J van der [Reactor Physics Department, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands); Dam, H van [Reactor Physics Department, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands)

    2004-09-21

    The values of the parameters used in boron neutron capture therapy (BNCT) to calculate a given dose to human tissue vary with patients due to different physical, biological and/or medical circumstances. Parameters include the tissue dimensions, the {sup 10}B concentration and the relative biological effectiveness (RBE) factors for the different dose components associated with BNCT. Because there is still no worldwide agreement on RBE values, more often than not, average values for these parameters are used. It turns out that the RBE-problem can be circumvented by taking into account all imaginable parameter values. Approaching this quest from another angle: the outcome will also provide the parameters (and values) which influence the optimal source neutron energy. For brain tumours it turns out that the {sup 10}B concentration, the RBE factors for {sup 10}B as well as fast neutrons, together with the dose limit set for healthy tissue, affect the optimal BNCT source neutron energy. By using source neutrons of a few keV together with neutrons of a few eV, it ensures that, under all imaginable circumstances, a maximum of alpha (and lithium) particles can be delivered in the tumour.

  20. Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

    International Nuclear Information System (INIS)

    Leith, J.T.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Howard, J.

    1982-01-01

    The thoraco-lumbar (T12-L1) region of the spinal cord of rats was exposed to either single or fractionated (four daily exposures) doses of X rays (230 kVp) or heavy ions. The heavy ions used were carbon and neon, and the relative biological effectiveness (RBE) of both the plateau ionization region and the midpeak region of 4-cm spread-out Bragg peaks of each heavy ion were investigated. For single doses of carbon and neon ions in the plateau ionization region, RBE values of 1.45 +/- 0.25 (propagated 95% confidence limits) and 1.46 +/- 0.33, respectively, were obtained. In the spread peak regions for carbon and neon ions, the RBE values were 1.48 +/- 0.18 and 1.86 +/- 0.42, respectively. These values were obtained using the dose needed to produce 50% paralysis in a group of irradiated rats as the isoeffect comparison dose (ED 50 dose). Similarly, in groups of rats receiving four daily exposures, the RBE values for carbon and neon ions in the plateau ionization region were 1.31 +/- 0.27 and 1.80 +/- 0.24, respectively. In the spread peak regions of ionization for carbon and neon ions, the RBE values were 1.95 +/- 0.19 and 2.18 +/- 0.23, respectively. Similar values for RBE were obtained using changes in the activity of enzymes in spinal cord tissue (cyclic nucleotide phosphohydrolase and γ-glutamyl transpeptidase). Also, it was estimated that, for X irradiation, the fractional amount of dose repaired (at the ED 50 dose) was 0.64 +/- 0.10 (95% confidence limits). For carbon and neon ions in the plateau ionization region, the values for the fractional amount of dose repaired were 0.70 +/- 0.27 and 0.48 +/- 0.20, and for carbon and neon ions in the spread peak region of ionization, the fractional repair values were 0.40 +/- 0.10 and 0.52 +/- 0.17. Spinal cord tissue therefore shows a high capacity for subeffective damage repair

  1. Collaborative partnership and the social value of clinical research: a qualitative secondary analysis.

    Science.gov (United States)

    Nurmi, Sanna-Maria; Halkoaho, Arja; Kangasniemi, Mari; Pietilä, Anna-Maija

    2017-10-25

    Protecting human subjects from being exploited is one of the main ethical challenges for clinical research. However, there is also a responsibility to protect and respect the communities who are hosting the research. Recently, attention has focused on the most efficient way of carrying out clinical research, so that it benefits society by providing valuable research while simultaneously protecting and respecting the human subjects and the communities where the research is conducted. Collaboration between partners plays an important role and that is why we carried out a study to describe how collaborative partnership and social value are emerging in clinical research. A supra-analysis design for qualitative descriptive secondary analysis was employed to consider a novel research question that pertained to nurse leaders' perceptions of ethical recruitment in clinical research and the ethics-related aspects of clinical research from the perspective of administrative staff. The data consisted of two separate pre-existing datasets, comprising 451 pages from 41 interviews, and we considered the research question by using deductive-inductive content analysis with NVivo software. A deductive analysis matrix was generated on the basis of two requirements, namely collaborative partnership and social value, as presented in An Ethical Framework for Biomedical Research by Emanuel et al. The findings showed that collaborative partnership was a cornerstone for ethical clinical research and ways to foster inter-partner collaboration were indicated, such as supporting mutual respect and equality, shared goals and clearly defined roles and responsibilities. In addition, the social value of clinical research was an important precondition for ethical clinical research and its realisation required the research partners to demonstrate collaboration and shared responsibility during the research process. However, concerns emerged that the multidimensional meaning of clinical research for

  2. Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

    International Nuclear Information System (INIS)

    Giantsoudi, Drosoula; Seco, Joao; Eaton, Bree R.; Simeone, F. Joseph; Kooy, Hanne; Yock, Torunn I.; Tarbell, Nancy J.; DeLaney, Thomas F.; Adams, Judith; Paganetti, Harald; MacDonald, Shannon M.

    2017-01-01

    body and allow for vertebral column growth for children with central nervous system tumors requiring CSI. This was true even when considering variable RBE values. A clinical trial is planned for VBS to the thoracic and lumbosacral spine in growing children.

  3. Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, Drosoula, E-mail: dgiantsoudi@mgh.harvard.edu; Seco, Joao; Eaton, Bree R.; Simeone, F. Joseph; Kooy, Hanne; Yock, Torunn I.; Tarbell, Nancy J.; DeLaney, Thomas F.; Adams, Judith; Paganetti, Harald; MacDonald, Shannon M.

    2017-05-01

    body and allow for vertebral column growth for children with central nervous system tumors requiring CSI. This was true even when considering variable RBE values. A clinical trial is planned for VBS to the thoracic and lumbosacral spine in growing children.

  4. In Vivo Radiobiological Characterization of Proton Beam at the National Cancer Center in Korea: Effect of the Chk2 Mutation

    International Nuclear Information System (INIS)

    Kim, Sang Soo; Choo, Dong Wan; Shin, Dongho; Baek, Hye Jung; Kim, Tae Hyun; Motoyama, Noboru; De Coster, Blanche M.; Gueulette, John; Furusawa, Yoshiya; Ando, Koichi; Cho, Kwan Ho

    2011-01-01

    Purpose: The relative biological effectiveness (RBE) in the presence or absence of CHK2 was estimated at the Korean National Cancer Center Proton Therapy Center (NCCPTC). Methods and Materials: The proton beam was fixed at 210 MeV with 6-cm spread-out Bragg peaks (SOBPs) because this is expected to be the most frequently used clinical setting. X-rays were obtained using a 6-MV conventional linear accelerator. The RBE was estimated from the survival of jejunal crypt in C3H/He and Chk2 -/- mice. Results: The estimated RBEs of the NCCPTC at the middle of the SOBP were 1.10 and 1.05 in the presence and absence of CHK2, respectively. The doses that reduced the number of regenerated crypt per jejunal circumference to 20 (D 20 ) in C3H/He mice were 14.8 Gy (95% confidence interval [CI], 13.7-15.9) for X-rays and 13.5 Gy (95% CI, 14.5-15.5) for protons. By contrast, the doses of D 20 in Chk2 -/- mice were 15.7 Gy (95% CI, 15.0-16.4) and 14.9 Gy (95% CI, 14.0-15.8) for X-rays and protons, respectively. Conclusions: The RBE of the NCCPTC is clearly within the range of RBEs determined at other facilities and is consistent with the generic RBE value of 1.10 for 150- to 250-MeV beams. The mutation of Chk2 gave rise to radioresistance but exhibited similar RBE.

  5. Clinical Pathways and the Patient Perspective in the Pursuit of Value-Based Oncology Care.

    Science.gov (United States)

    Ersek, Jennifer L; Nadler, Eric; Freeman-Daily, Janet; Mazharuddin, Samir; Kim, Edward S

    2017-01-01

    The art of practicing oncology has evolved substantially in the past 5 years. As more and more diagnostic tests, biomarker-directed therapies, and immunotherapies make their way to the oncology marketplace, oncologists will find it increasingly difficult to keep up with the many therapeutic options. Additionally, the cost of cancer care seems to be increasing. Clinical pathways are a systematic way to organize and display detailed, evidence-based treatment options and assist the practitioner with best practice. When selecting which treatment regimens to include on a clinical pathway, considerations must include the efficacy and safety, as well as costs, of the therapy. Pathway treatment regimens must be continually assessed and modified to ensure that the most up-to-date, high-quality options are incorporated. Value-based models, such as the ASCO Value Framework, can assist providers in presenting economic evaluations of clinical pathway treatment options to patients, thus allowing the patient to decide the overall value of each treatment regimen. Although oncologists and pathway developers can decide which treatment regimens to include on a clinical pathway based on the efficacy of the treatment, assessment of the value of that treatment regimen ultimately lies with the patient. Patient definitions of value will be an important component to enhancing current value-based oncology care models and incorporating new, high-quality, value-based therapeutics into oncology clinical pathways.

  6. WE-H-BRA-07: Mechanistic Modelling of the Relative Biological Effectiveness of Heavy Charged Particles

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, S [Massachusetts General Hospital, Boston, MA (United States); Queen’s University, Belfast, Belfast (United Kingdom); McNamara, A; Schuemann, J; Paganetti, H [Massachusetts General Hospital, Boston, MA (United States); Prise, K [Queen’s University, Belfast, Belfast (United Kingdom)

    2016-06-15

    Purpose Uncertainty in the Relative Biological Effectiveness (RBE) of heavy charged particles compared to photons remains one of the major uncertainties in particle therapy. As RBEs depend strongly on clinical variables such as tissue type, dose, and radiation quality, more accurate individualised models are needed to fully optimise treatments. MethodsWe have developed a model of DNA damage and repair following X-ray irradiation in a number of settings, incorporating mechanistic descriptions of DNA repair pathways, geometric effects on DNA repair, cell cycle effects and cell death. Our model has previously been shown to accurately predict a range of biological endpoints including chromosome aberrations, mutations, and cell death. This model was combined with nanodosimetric models of individual ion tracks to calculate the additional probability of lethal damage forming within a single track. These lethal damage probabilities can be used to predict survival and RBE for cells irradiated with ions of different Linear Energy Transfer (LET). ResultsBy combining the X-ray response model with nanodosimetry information, predictions of RBE can be made without cell-line specific fitting. The model’s RBE predictions were found to agree well with empirical proton RBE models (Mean absolute difference between models of 1.9% and 1.8% for cells with α/β ratios of 9 and 1.4, respectively, for LETs between 0 and 15 keV/µm). The model also accurately recovers the impact of high-LET carbon ion exposures, showing both the reduced efficacy of ions at extremely high LET, as well as the impact of defects in non-homologous end joining on RBE values in Chinese Hamster Ovary cells.ConclusionOur model is predicts RBE without the inclusion of empirical LET fitting parameters for a range of experimental conditions. This approach has the potential to deliver improved personalisation of particle therapy, with future developments allowing for the calculation of individualised RBEs. SJM is

  7. Critical value reporting: a survey of 36 clinical laboratories in South Africa.

    Science.gov (United States)

    Schapkaitz, Elise; Mafika, Zipho

    2013-10-11

    Critical value policies are used by clinical laboratories to decide when to notify caregivers of life-threatening results. Despite their widespread use, critical value policies have not been published locally. A survey was designed to determine critical value policies for haematology tests in South Africa. A survey was carried out on 136 identified laboratories across South Africa in January 2013. Of these, 36 responded. Data collected included critical value policies, critical values for haematology parameters, and critical value reporting. Of the 36 laboratories surveyed, 11.1% (n=4) were private, 33.3% (n=12) were affiliated to academic institutions and 55.6% (n=20) were peripheral or regional National Health Laboratory Service laboratories. All the laboratories confirmed that they had a critical value policy, and 83.3% of such policies were derived from local clinical opinion. Mean low and high critical limits for the most frequently listed tests were as follows: haemoglobin 20 g/dl, platelet count 1 000 ×10(9)/l, white cell count 46 ×10(9)/l, activated partial thromboplastin time >101 seconds, and international normalised ratio >6. In almost all cases critical value reporting was performed by the technologist on duty (97.2%). The majority of laboratories required that the person notified of the critical value be the doctor who ordered the test or the caregiver directly involved in the patient's care (83.3%); 73.3% of laboratories indicated that they followed an algorithm if the doctor/caregiver could not be reached. Each laboratory is responsible for establishing clinically relevant critical limits. Clinicians should be involved in developing the laboratory's critical value policy. The findings of this survey may be of value to local laboratories that are in the process of establishing or reviewing critical value policies.

  8. The value of pathogen information in treating clinical mastitis

    NARCIS (Netherlands)

    Cha, Elva; Smith, Rebecca L.; Kristensen, Anders R.; Hertl, Julia A.; Schukken, Ynte H.; Tauer, Loren W.; Welcome, Frank L.; Gröhn, Yrjö T.

    2016-01-01

    The objective of this study was to determine the economic value of obtaining timely and more accurate clinical mastitis (CM) test results for optimal treatment of cows. Typically CM is first identified when the farmer observes recognisable outward signs. Further information of whether the

  9. The value of pathogen information in treating clinical mastitis

    NARCIS (Netherlands)

    Cha, Elva; Smith, Rebecca L.; Kristensen, Anders R.; Hertl, Julia A.; Schukken, Ynte H.; Tauer, Loren W.; Welcome, Frank L.; Gröhn, Yrjö T.

    2016-01-01

    The objective of this study was to determine the economic value of obtaining timely and more accurate clinical mastitis (CM) test results for optimal treatment of cows. Typically CM is first identified when the farmer observes recognisable outward signs. Further information of whether the pathogen

  10. Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapy

    International Nuclear Information System (INIS)

    Wang, Jian Z.; Mayr, Nina A.; Nag, Subir; Montebello, Joseph; Gupta, Nilendu; Samsami, Nina; Kanellitsas, Christos

    2006-01-01

    Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters (α=0.15 Gy -1 and α/β=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD 2 ) with respect to three effects: edema, RBE, and dose heterogeneity for 125 I and 103 Pd implants. The EUD 2 analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V 100 (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D 90 (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for 125 I and 103 Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for 125 I and 1.3-1.6 for 103 Pd implants. These RBE values are consistent with the RBE data published in the literature. These results may explain why in earlier modeling studies

  11. Low LET protons focused to submicrometer shows enhanced radiobiological effectiveness

    Science.gov (United States)

    Schmid, T. E.; Greubel, C.; Hable, V.; Zlobinskaya, O.; Michalski, D.; Girst, S.; Siebenwirth, C.; Schmid, E.; Molls, M.; Multhoff, G.; Dollinger, G.

    2012-10-01

    This study shows that enhanced radiobiological effectiveness (RBE) values can be generated focusing low linear energy transfer (LET) radiation and thus changing the microdose distribution. 20 MeV protons (LET = 2.65 keV µm-1) are focused to submicrometer diameter at the ion microprobe superconducting nanoprobe for applied nuclear (Kern) physics experiments of the Munich tandem accelerator. The RBE values, as determined by measuring micronuclei (RBEMN = 1.48 ± 0.07) and dicentrics (RBED = 1.92 ± 0.15), in human-hamster hybrid (AL) cells are significantly higher when 117 protons were focused to a submicrometer irradiation field within a 5.4 × 5.4 µm2 matrix compared to quasi homogeneous in a 1 × 1 µm2 matrix applied protons (RBEMN = 1.28 ± 0.07; RBED = 1.41 ± 0.14) at the same average dose of 1.7 Gy. The RBE values are normalized to standard 70 kV (dicentrics) or 200 kV (micronuclei) x-ray irradiation. The 117 protons applied per point deposit the same amount of energy like a 12C ion with 55 MeV total energy (4.48 MeV u-1). The enhancements are about half of that obtained for 12C ions (RBEMN = 2.20 ± 0.06 and RBED = 3.21 ± 0.10) and they are attributed to intertrack interactions of the induced damages. The measured RBE values show differences from predictions of the local effect model (LEM III) that is used to calculate RBE values for irradiation plans to treat tumors with high LET particles.

  12. Clinical value of natriuretic peptides in chronic kidney disease.

    Science.gov (United States)

    Santos-Araújo, Carla; Leite-Moreira, Adelino; Pestana, Manuel

    2015-01-01

    According to several lines of evidence, natriuretic peptides (NP) are the main components of a cardiac-renal axis that operate in clinical conditions of decreased cardiac hemodynamic tolerance to regulate sodium homeostasis, blood pressure and vascular function. Even though it is reasonable to assume that NP may exert a relevant role in the adaptive response to renal mass ablation, evidence gathered so far suggest that this contribution is probably complex and dependent on the type and degree of the functional mass loss. In the last years NP have been increasingly used to diagnose, monitor treatment and define the prognosis of several cardiovascular (CV) diseases. However, in many clinical settings, like chronic kidney disease (CKD), the predictive value of these biomarkers has been questioned. In fact, it is now well established that renal function significantly affects the plasmatic levels of NP and that renal failure is the clinical condition associated with the highest plasmatic levels of these peptides. The complexity of the relation between NP plasmatic levels and CV and renal functions has obvious consequences, as it may limit the predictive value of NP in CV assessment of CKD patients and be a demanding exercise for clinicians involved in the daily management of these patients. This review describes the role of NP in the regulatory response to renal function loss and addresses the main factors involved in the clinical valorization of the peptides in the context of significant renal failure. Copyright © 2015 The Authors. Published by Elsevier España, S.L.U. All rights reserved.

  13. Cell inactivation and chromosomal aberrations induced by X-rays and fast neutrons in cells of the Chinese hamster. 1

    International Nuclear Information System (INIS)

    Tolkendorf, E.

    1979-01-01

    Asynchronously grown cultures of Chinese hamster cells V79-4 were irradiated in suspension with 180 kV X-rays and fast neutrons (average energy of 6.2 MeV). The damage was assessed by measuring cell survival and frequencies of chromosome aberrations in the first post-irradiation metaphases. The experimental data for survival and chromosome aberrations were fitted by computer programmes. From the fitted curves the relative biological effectiveness (RBE) of fast neutrons was calculated. The RBE shows a similar dose dependence for killed and aberrant cells. The RBE decreases with increasing dose and amounts to approximately 5 for both effects for small neutron doses. The highest RBE is found for asymmetrical chromosomal exchanges and is dependent on the neutron dose, too. However, for isochromatid deletions the RBE is dose independent with a value of 3.6. (author)

  14. Calculation of complication probability of pion treatment at PSI using dose-volume histograms

    International Nuclear Information System (INIS)

    Nakagawa, Keiichi; Akanuma, Atsuo; Aoki, Yukimasa

    1991-01-01

    In the conformation technique a target volume is irradiated uniformly as in conventional radiations, whereas surrounding tissue and organs are nonuniformly irradiated. Clinical data on radiation injuries that accumulate with conventional radiation are not applicable without appropriate compensation. Recently a putative solution of this problem was proposed by Lyman using dose-volume histograms. This histogram reduction method reduces a given dose-volume histogram of an organ to a single step which corresponds to the equivalent complication probability by interpolation. As a result it converts nonuniform radiation into a unique dose to the whole organ which has the equivalent likelihood of radiation injury. This method is based on low LET radiation with conventional fractionation schedules. When it is applied to high LET radiation such as negative pion treatment, a high LET dose should be converted to an equivalent photon dose using an appropriate value of RBE. In the present study the histogram reduction method was applied to actual patients treated by the negative pion conformation technique at the Paul Scherrer Institute. Out of evaluable 90 cases of pelvic tumors, 16 developed grade III-IV bladder injury, and 7 developed grade III-IV rectal injury. The 90 cases were divided into roughly equal groups according to the equivalent doses to the entire bladder and rectum. Complication rates and equivalent doses to the full organs in these groups could be represented by a sigmoid dose-effect relation. When RBE from a pion dose to a photon dose is assumed to be 2.1 for bladder injury, the rates of bladder complications fit best to the theoretical complication curve. When the RBE value was 2.3, the rates of rectal injury fit the theoretical curve best. These values are close to the conversion factor of 2.0 that is used in clinical practice at PSI. This agreement suggests the clinical feasibility of the histogram reduction method in conformation radiotherapy. (author)

  15. The Value of Clinical Jazz: Teaching Critical Reflection on, in, and Toward Action.

    Science.gov (United States)

    Casapulla, Sharon; Longenecker, Randall; Beverly, Elizabeth A

    2016-05-01

    Clinical Jazz is a small-group strategy in medical education designed to develop interpersonal skills and improve doctor-patient and interprofessional relationships. The purpose of this study was to explore medical students' and faculty facilitators' perceived value of Clinical Jazz. We conducted a modified Nominal Group Process with participating medical students (n=21), faculty facilitators (n=5), and research team members (n=3). Students and faculty facilitators independently answered the question, "What do you value about Clinical Jazz?" We then conducted content and thematic analyses on the resulting data. Three themes emerged during analysis: (1) students and faculty appreciated the opportunity to learn and practice a thoughtful and structured process for problem solving, (2) students and faculty valued the safety of the group process in sharing a diversity of perspectives on topics in medicine, and (3) students and faculty acknowledged the importance of addressing real and challenging problems that are rarely addressed in formal lectures and other planned small-group settings. Clinical Jazz provides students and faculty with the opportunity to address the hidden and/or informal curriculum in medical education, while providing a safe space and time to solve important clinical and interprofessional problems.

  16. Are exposure index values consistent in clinical practice? A multi-manufacturer investigation

    International Nuclear Information System (INIS)

    Butler, M. L.; Rainford, L.; Last, J.; Brennan, P. C.

    2010-01-01

    The advent of digital radiography poses the risk of unnoticed increases in patient dose. Manufacturers have responded to this by offering an exposure index (EI) value to the clinician. Whilst the EI value is a measure of the air kerma at the detector surface, it has been recommended by international agencies as a method of monitoring radiation dose to the patient. Recent studies by the group have shown that EI values are being used in clinical practice to monitor radiation dose and assess image quality. This study aims to compare the clinical consistency of the EI value in computed radiography (CR) and direct digital radiography (DR) systems. An anthropomorphic phantom was used to simulate four common radiographic examinations: skull, pelvis, chest and hand. These examinations were chosen as they provide contrasting exposure parameters, image detail and radiation dose measurements. Four manufacturers were used for comparison: Agfa Gaevert CR, Carestream CR, Philips Digital Diagnost DR and Siemens DR. For each examination, the phantom was placed in the optimal position and exposure parameters were chosen in accordance with European guidelines and clinical practice. Multiple exposures were taken and the EI recorded. All exposure parameters and clinical conditions remained constant throughout. For both DR systems, the EI values remained consistent throughout. No significant change was noted in any examination. In both CR systems, there were noteworthy fluctuations in the EI values for all examinations. The largest for the Agfa system was a variation of 1.88-2.21 for the skull examination. This represents to the clinician a doubling of detector dose, despite all exposure parameters remaining constant. In the Kodak system, the largest fluctuation was seen for the chest examination where the EI ranged from 2560 to 2660, representing approximately an increase of 30% in radiation dose, despite consistent parameters. The fluctuations seen with the CR systems are most likely

  17. The FLUKA Monte Carlo code coupled with the local effect model for biological calculations in carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mairani, A [University of Pavia, Department of Nuclear and Theoretical Physics, and INFN, via Bassi 6, 27100 Pavia (Italy); Brons, S; Parodi, K [Heidelberg Ion Beam Therapy Center and Department of Radiation Oncology, Im Neuenheimer Feld 450, 69120 Heidelberg (Germany); Cerutti, F; Ferrari, A; Sommerer, F [CERN, 1211 Geneva 23 (Switzerland); Fasso, A [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Kraemer, M; Scholz, M, E-mail: Andrea.Mairani@mi.infn.i [GSI Biophysik, Planck-Str. 1, D-64291 Darmstadt (Germany)

    2010-08-07

    Clinical Monte Carlo (MC) calculations for carbon ion therapy have to provide absorbed and RBE-weighted dose. The latter is defined as the product of the dose and the relative biological effectiveness (RBE). At the GSI Helmholtzzentrum fuer Schwerionenforschung as well as at the Heidelberg Ion Therapy Center (HIT), the RBE values are calculated according to the local effect model (LEM). In this paper, we describe the approach followed for coupling the FLUKA MC code with the LEM and its application to dose and RBE-weighted dose calculations for a superimposition of two opposed {sup 12}C ion fields as applied in therapeutic irradiations. The obtained results are compared with the available experimental data of CHO (Chinese hamster ovary) cell survival and the outcomes of the GSI analytical treatment planning code TRiP98. Some discrepancies have been observed between the analytical and MC calculations of absorbed physical dose profiles, which can be explained by the differences between the laterally integrated depth-dose distributions in water used as input basic data in TRiP98 and the FLUKA recalculated ones. On the other hand, taking into account the differences in the physical beam modeling, the FLUKA-based biological calculations of the CHO cell survival profiles are found in good agreement with the experimental data as well with the TRiP98 predictions. The developed approach that combines the MC transport/interaction capability with the same biological model as in the treatment planning system (TPS) will be used at HIT to support validation/improvement of both dose and RBE-weighted dose calculations performed by the analytical TPS.

  18. Clinical Value of Treponema pallidum Real-Time PCR for Diagnosis of Syphilis

    NARCIS (Netherlands)

    Heymans, R.; van der Helm, J. J.; de Vries, H. J. C.; Fennema, H. S. A.; Coutinho, R. A.; Bruisten, S. M.

    2010-01-01

    The diagnosis of syphilis can be complicated when it is based on diverse clinical manifestations, dark-field microscopy, and serology. In the present study, therefore, we examined the additional clinical value of a Treponema pallidum real-time TaqMan PCR for the detection of primary and secondary

  19. What kind of radiobiology should be done at a hadron therapy center

    International Nuclear Information System (INIS)

    Kraft, G.; Kraft-Weyrather, W.; Taucher-Scholz, G.; Scholz, M.

    1997-01-01

    Although therapy with heavy particles like neutrons, protons or heavier ions has now a rather long history of several decades, but there are more open questions than settled problems. This fact is really amazing because the use of the high LET particles, neutrons and heavy ions was strongly motivated by radiobiological arguments. Presently, the use of protons with a better physical dose distribution is more widely accepted than neutrons or heavy ions where the expected high LET benefit could not be verified clinically. This demonstrates that predictions made on the basis of radiobiological experiments cannot be transferred directly from in vitro experiments to the therapy situation. In particular, it is not possible to transfer an average RBE value measured in vitro in an extended exposure field to the treatment situation. Therefore, in the following section the dependence of RBE on LET, dose and radiosensitivity will be summarized and compared to models. Basic experiments illustrating the RBE problem in a particle field will be described. The fundamentals of a recently developed track structure model will be given and calculations will be compared to experiments. Finally, a short outline of possible future developments for radiobiology will be presented. (orig.)

  20. Induction of spinal cord paralysis by negative pi-mesons

    International Nuclear Information System (INIS)

    Amols, H.I.; Yuhas, J.M.

    1981-01-01

    As part of an investigation on late non-neoplastic injury induced by negative pi-mesons (pions), a series of studies have been performed using pion beams for the induction of spinal cord paralysis in the Fisher 344 rat. Groups of rats were exposed to 1, 5 or 15 daily doses of peak pions or X rays. Paralysis appeared earlier after treatment with pions than after X-rays even in a comparison of groups with similar final incidences. A single dose RBE for spinal cord paralysis of 1.3 was found. The RBE rises to a value of 3.2 if the total dose is given as a series of 15 daily exposures. These RBEs are far larger than those observed using other late injury end-points, such as tubular degeneration in the kidney or fibrosis and sclerosis in the support structures of the colon for which the single dose RBE is less than 1.2. The biological and/or physical basis for the high sensitivity of the spinal cord to peak pions has not yet been resolved, but these data have suggested caution in exposing the spinal cord to peak pions in clinical trials. (author)

  1. Lateral variations of radiobiological properties of therapeutic fields of 1H, 4He, 12C and 16O ions studied with Geant4 and microdosimetric kinetic model

    Science.gov (United States)

    Dewey, Sophie; Burigo, Lucas; Pshenichnov, Igor; Mishustin, Igor; Bleicher, Marcus

    2017-07-01

    As known, in cancer therapy with ion beams the relative biological effectiveness (RBE) of ions changes in the course of their propagation in tissues. Such changes are caused not only by increasing the linear energy transfer (LET) of beam particles with the penetration depth towards the Bragg peak, but also by nuclear reactions induced by beam nuclei leading to the production of various secondary particles. Although the changes of RBE along the beam axis have been studied quite well, much less attention has been paid to the evolution of RBE in the transverse direction, perpendicular to the beam axis. In order to fill this gap, we simulated radiation fields of 1H, 4He, 12C and 16O nuclei of 20 mm in diameter by means of a Geant4-based Monte Carlo model for heavy-ion therapy connected with the modified microdosimetric kinetic model to describe the response of normal ((α/β)_x-rays=3.8 Gy) and early-responding ((α/β)_x-rays=10 Gy) tissues. Depth and radial distributions of saturation-corrected dose-mean lineal energy, RBE and RBE-weighted dose are investigated for passive beam shaping and active beam scanning. The field of 4He has a small lateral spread as compared with 1H field, and it is characterised by a modest lateral variation of RBE suggesting the use of fixed RBE values across the field transverse cross section at each depth. Reduced uncertainties of RBE on the boundary of a 4He treatment field can be advantageous in a specific case of an organ at risk located in lateral proximity to the target volume. It is found that the lateral distributions of RBE calculated for 12C and 16O fields demonstrate fast variations in the radial direction due to changes of dose and composition of secondary fragments in the field penumbra. Nevertheless, the radiation fields of all four projectiles at radii larger than 20 mm can be characterized by a common RBE value defined by tissue radiosensitivity. These findings can help, in particular, in accessing the transverse

  2. Short-term biological variation of clinical chemical values in dumeril's monitors (Varanus dumerili)

    DEFF Research Database (Denmark)

    Bertelsen, Mads Frost; Kjelgaard-Hansen, Mads Jens; Howell, Jennifer R.

    2007-01-01

    Plasma biochemical values are routinely used in the medical management of ill reptiles, and for monitoring the health of clinically normal animals. Laboratory tests, including clinical biochemical values, are subject to biological and analytical variation, the magnitude of which determines the ut...

  3. Relative biological effectiveness if alpha radiation for human lung exposure

    International Nuclear Information System (INIS)

    Yarmoshenko, I.; Kirdin, I.; Zhukovsky, M.

    2006-01-01

    Full text of publication follows: The concept of RBE, which introduced by ICRP and ICRU about 50 years ago to compare biological effects of ionizing radiation of different types, still continues to be the essential element of current and projected radiation protection systems in terms of deriving quantities (quality factor and radiation weighting factor). For example, RBE for the stochastic effects induction has to be considered for appropriate radiation weighting of the absorbed dose while estimating equivalent dose. Simulation of lung cancer radiation risk for the cases of inhalation of radon progeny and incorporation of plutonium in lung in comparison with external reference radiation allows assessment of RBE for alpha-radiation. Specific radiation risk models were developed by results of the direct epidemiological studies and used for such simulation. Simulation included published risk models for nuclear workers of the Mayak facilities in the former Soviet Union exposed to incorporated plutonium (Kreisheimer et al., 2003; Gilbert et al., 2004) and underground miners exposed to radon progenies (BEIR VI, 1999). Additionally lung cancer risk model was developed for a case of population indoor radon exposure. Lung cancer risk related to external exposure is estimated using the risk model develop ed using data of Life Span Study of Japanese atomic bomb survivors. By results of lifetime lung cancer risk simulation using Monte Carlo approach estimated median value of RBE in case of indoor radon exposure is 1.5 (with 90% range 0.4 to 7). In case of the two models developed by BEIR VI for lung cancer risk due to radon exposure in underground miners the median values of RBE are 2.1 and 4.4 (with 90% ranges 0.3 to 17 and 0.7 to 45) respectively.Two different models for lung cancer risk related to plutonium exposure resulted in close estimates of RBE: median value of 12 and 13 (with 90% range 4 to 104 and 4 to 136) respectively. Considerable discrepancy between RBE

  4. Efficacy and predictive value of clinical stage in non-surgical patients with esophageal cancer

    International Nuclear Information System (INIS)

    Liu Xiao; Wang Guiqi; He Shun

    2014-01-01

    Objective: To investigate the efficacy and predictive value of clinical stage in non-surgical patients with esophageal cancer (EC). Methods: A retrospective study was conducted in 358 EC patients who underwent radical surgery in our hospital from April 2003 to October 2010 and who had preoperative work-up including endoscopic esophageal ultrasound (EUS), esophagoscopy, thoracic CT scans,and contrast esophagography and had detailed information on postoperative pathological stages. The predictive value of preoperative clinical T/N stage based on EUS + CT for postoperative pathological stage was analyzed. The disease free survival (DFS) and overall survival (OS) were analyzed according to the UICC TNM classification (2002/ 2009) and the clinical stage based on imaging findings. Results: The median follow-up was 47 months.A total of 305 (85.2%) of all patients were analyzed by clinical stage based on EUS + CT.Among them, the predictive value of clinical T stage for pathological T stage was 0-88.6%, highest (88.6%) for T1 stage and lowest for T4 stage. The predictive value of clinical N stage (N 0 /N1) was 62.5-100%. The significant differences in OS and DFS rates based on both 2002 and 2009 UICC TNM classifications were noted (P=0.000 and 0.000). There were significant differences in OS between stage groups, except the comparison between two stage Ⅳ patients and other groups, according to 2002 UICC TNM classification. There were usually insignificant differences in OS between stage groups, according to 2009 UICC TNM classification. For the 305 patients staged clinically based on EUS and CT according to 2002 UICC TNM classification, significant differences in OS and DFS rates were noted (P=0.000 and 0.000). Conclusions: Imaging modalities show good predictive value for N stage (N0/N1),even though they cannot accurately provide the number of metastatic lymph nodes. The clinical stage based on EUS + CT can effectively predict the prognosis of non-surgical EC patients

  5. Clinical impact and value of workstation single sign-on.

    Science.gov (United States)

    Gellert, George A; Crouch, John F; Gibson, Lynn A; Conklin, George S; Webster, S Luke; Gillean, John A

    2017-05-01

    CHRISTUS Health began implementation of computer workstation single sign-on (SSO) in 2015. SSO technology utilizes a badge reader placed at each workstation where clinicians swipe or "tap" their identification badges. To assess the impact of SSO implementation in reducing clinician time logging in to various clinical software programs, and in financial savings from migrating to a thin client that enabled replacement of traditional hard drive computer workstations. Following implementation of SSO, a total of 65,202 logins were sampled systematically during a 7day period among 2256 active clinical end users for time saved in 6 facilities when compared to pre-implementation. Dollar values were assigned to the time saved by 3 groups of clinical end users: physicians, nurses and ancillary service providers. The reduction of total clinician login time over the 7day period showed a net gain of 168.3h per week of clinician time - 28.1h (2.3 shifts) per facility per week. Annualized, 1461.2h of mixed physician and nursing time is liberated per facility per annum (121.8 shifts of 12h per year). The annual dollar cost savings of this reduction of time expended logging in is $92,146 per hospital per annum and $1,658,745 per annum in the first phase implementation of 18 hospitals. Computer hardware equipment savings due to desktop virtualization increases annual savings to $2,333,745. Qualitative value contributions to clinician satisfaction, reduction in staff turnover, facilitation of adoption of EHR applications, and other benefits of SSO are discussed. SSO had a positive impact on clinician efficiency and productivity in the 6 hospitals evaluated, and is an effective and cost-effective method to liberate clinician time from repetitive and time consuming logins to clinical software applications. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Clinical value of ambulatory blood pressure: evidence and limits.

    Science.gov (United States)

    Mancia, Giuseppe; Verdecchia, Paolo

    2015-03-13

    This article reviews the clinical value of ambulatory blood pressure (BP) vis-à-vis the traditional BP measurements taken in the physician's office or in the hospital. Mention is initially made that longitudinal studies conducted in the general population or in hypertensive cohorts have shown that ambulatory BP provides a more accurate prediction of outcome than office BP. Namely, that (1) the risk of cardiovascular events increases in a less steep fashion with office than with 24-hour mean BP, (2) the 24-hour BP-dependent prediction is maintained after adjustment for office BP values, and (3) among individuals with normal office BP, those with increased ambulatory BP (masked hypertension) have an increased prevalence of organ damage, a more frequent unfavorable metabolic profile and a higher risk of new onset sustained hypertension, diabetes mellitus, and cardiovascular events than those with normal ambulatory BP. It is further mentioned, however, that more recently similar observations have been made for individuals with high office but normal ambulatory BP (white coat hypertension) suggesting a complementary role of out-of-office and office BP values in the determination of patients' prognosis. The evidence in favor of an independent prognostic value also of some within 24-hour BP phenomena (night BP reduction or absolute values, short-term BP variations, and morning BP surge) is then critically appraised for its elements of strength and weakness. Finally, whether the clinical advantages of ambulatory BP make this approach necessary for all patients with hypertension is discussed. The conclusion is that this is at present still premature because crucial evidence pro or against routine use of this approach in untreated and treated hypertensives is not yet available. It will be crucial for future studies to determine whether, compared with a treatment guided by office BP, a treatment tailored on ambulatory BP allows to improve prevention or regression of organ

  7. Implementation of spot scanning dose optimization and dose calculation for helium ions in Hyperion

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Hermann, E-mail: hermann.fuchs@meduniwien.ac.at [Department of Radiation Oncology, Division of Medical Radiation Physics, Medical University of Vienna/AKH Vienna, Vienna 1090, Austria and Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna 1090 (Austria); Alber, Markus [Department for Oncology, Aarhus University Hospital, Aarhus 8000 (Denmark); Schreiner, Thomas [PEG MedAustron, Wiener Neustadt 2700 (Austria); Georg, Dietmar [Department of Radiation Oncology, Division of Medical Radiation Physics, Medical University of Vienna/AKH Vienna, Vienna 1090 (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna 1090 (Austria); Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, Vienna 1090 (Austria)

    2015-09-15

    Purpose: Helium ions ({sup 4}He) may supplement current particle beam therapy strategies as they possess advantages in physical dose distribution over protons. To assess potential clinical advantages, a dose calculation module accounting for relative biological effectiveness (RBE) was developed and integrated into the treatment planning system Hyperion. Methods: Current knowledge on RBE of {sup 4}He together with linear energy transfer considerations motivated an empirical depth-dependent “zonal” RBE model. In the plateau region, a RBE of 1.0 was assumed, followed by an increasing RBE up to 2.8 at the Bragg-peak region, which was then kept constant over the fragmentation tail. To account for a variable proton RBE, the same model concept was also applied to protons with a maximum RBE of 1.6. Both RBE models were added to a previously developed pencil beam algorithm for physical dose calculation and included into the treatment planning system Hyperion. The implementation was validated against Monte Carlo simulations within a water phantom using γ-index evaluation. The potential benefits of {sup 4}He based treatment plans were explored in a preliminary treatment planning comparison (against protons) for four treatment sites, i.e., a prostate, a base-of-skull, a pediatric, and a head-and-neck tumor case. Separate treatment plans taking into account physical dose calculation only or using biological modeling were created for protons and {sup 4}He. Results: Comparison of Monte Carlo and Hyperion calculated doses resulted in a γ{sub mean} of 0.3, with 3.4% of the values above 1 and γ{sub 1%} of 1.5 and better. Treatment plan evaluation showed comparable planning target volume coverage for both particles, with slightly increased coverage for {sup 4}He. Organ at risk (OAR) doses were generally reduced using {sup 4}He, some by more than to 30%. Improvements of {sup 4}He over protons were more pronounced for treatment plans taking biological effects into account. All

  8. CLINICAL VALUE OF CHROMOGRANIN A IN GASTROENTEROPANCREATIC NEUROENDOCRINE TUMORS

    Directory of Open Access Journals (Sweden)

    N. V. Lyubimova

    2015-01-01

    Full Text Available Background: Neuroendocrine tumors (NET is a heterogeneous group of neoplasms characterized by hypersecretion of biologically active sub- stances that manifests by specific syndromes and determines the clinical course of the disease. The most common NET types are those of gastrointestinal tract. The obligatory biochemical marker used in the examination of NET patients is chromogranin A (CgA.Aim: Evaluation of the CgA value for diagnostics and monitoring of gastrointestinal NETs.Materials and methods: A comparative study of plasma CgA levels was performed in 146 patients with gastroenteropancreatic neuroendocrine tu- mors and 66 healthy individuals using the enzyme immunoassay “Chromogranin A ELISA kit” (Dako A/S, Denmark.Results: CgA levels were significantly higher in patients with NETs of all localizations, such as pancreas, stomach, gut, small and large bowel, than in the healthy subjects (р < 0.000001. In NET patients, CgA secretion was highly variable, with the highest value in the group of patients with gastric NETs (102000 U/l. The highest CgA medians were detected in patients with small intestinal (183.9 U/l, colon (148.4 U/l and pancreatic (135.9 U/l NETs. There was an association between CgA secretion and extension or activity of NETs, with the highest median values in patients with hepatic metastases (395 U/l and those with carcinoid syndrome (352 U/l. The clinical significance of CgA as a NET marker was assessed using the cut-off value of 33 U/l, calculated according to the results in the control group. Overall diagnostic sensitivity of CgA in NET patients was high (85.8% with a specificity of 98.5%. Conclusion: The results obtained confirm a high sensitivity of CgA as a NET marker whose determination helps to improve accuracy of diagnostics and to assess NET prevalence.

  9. Radiotoxicity of gadolinium-148 and radium-223 in mouse testes: Relative biological effectiveness of alpha-particle emitters in vivo

    International Nuclear Information System (INIS)

    Howell, R.W.; Goddu, S.M.; Narra, V.R.

    1997-01-01

    The biological effects of radionuclides that emit α particles are of considerable interest in view of their potential for therapy and their presence in the environment. The present work is a continuation of our ongoing effort to study the radiotoxicity of α-particle emitters in vivo using the survival of murine testicular sperm heads as the biological end point. Specifically, the relative biological effectiveness (RBE) of very low-energy α particles (3.2 MeV) emitted by 148 Gd is investigated and determined to be 7.4 ± 2.4 when compared to the effects of acute external 120 kVp X rays. This datum, in conjunction with our earlier results for 210 Po and 212 Pb in equilibrium with its daughters, is used to revise and extend the range of validity of our previous RBE-energy relationship for α particles emitted by tissue-incorporated radionuclides. The new empirical relationship is given by RBE α = 9.14 - 0.510 E α , where 3 α 223 Ra (in equilibrium with its daughters) experimentally in the same biological model and comparing the value obtained experimentally with the predicted value. The resulting RBE values are 5.4 ± 0.9 and 5.6, respectively. This close agreement strongly supports the adequacy of the empirical RBE-E α relationship to predict the biological effects of α-particle emitters in vivo. 42 refs., 5 figs., 1 tab

  10. Clinical value of Tei index in pediatric patients with repaired tetralogy of Fallot.

    Science.gov (United States)

    Song, Bing; Qi, Quan; Liu, Ruisheng; Xing, Wang; Tang, Hanbo; Li, Yuanmin

    2015-01-01

    Tetralogy of Fallot is a congenital heart disease characterized by underdevelopment of the right ventricular infundibulum. Present study aimed to explore the clinic value of Tei index in assessing right ventricular function of pediatric patients with repaired Tetralogy of Fallot. A total of 45 pediatric patients with repaired Tetralogy of Fallot were recruited and classified into: group A (Tei index 0.7; n=13, aging 4-14 years). The right ventricular Tei index value was related to the clinical characteristics of Tetralogy of Fallot repair patients. Right ventricular Tei index was positively correlated with ventilation time, drainage volumes, and negatively with drug assistance and Intensive Care Unit (ICU) stay, although time for drug assistance and ICU stay were not statically different between group B and group C. There was no significant difference in left ventricular ejection fraction. Tei index is a sensitive indicator of right ventricular dysfunction, and has important clinical value to better our understanding of right ventricular function after tetralogy of Fallot repair.

  11. Driving out waste: a framework to enhance value in clinical care.

    Science.gov (United States)

    Burton, David A

    2013-06-01

    Many healthcare providers today are seeking to improve the value of the care they deliver by implementing standardized clinical practice guidelines aimed at reducing variations in care, avoiding complications, and lowering costs. To succeed, such an initiative requires the full support and participation of the clinicians who will use the guidelines. Providers also should have a fully developed infrastructure consisting of a clinical content system, an analytics system, and a deployment system.

  12. Significance and clinical value of the transitional zone volume (TZV ...

    African Journals Online (AJOL)

    M. El Ghoneimy

    2017-01-12

    Jan 12, 2017 ... Objective: The aim of this work was to evaluate the significance and clinical value of the TZI, which has been a point of ... Conclusion: Estimating the transition zone volume during TRUS is a reasonable way to obtain the required ... Besides the IPSS score, a complete medical and surgical history was also.

  13. Microdosimetric measurements in the thermal neutron irradiation facility of LENA reactor

    International Nuclear Information System (INIS)

    Colautti, P.; Moro, D.; Chiriotti, S.; Conte, V.; Evangelista, L.; Altieri, S.; Bortolussi, S.; Protti, N.; Postuma, I.

    2014-01-01

    A twin TEPC with electric-field guard tubes has been constructed to be used to characterize the BNCT field of the irradiation facility of LENA reactor. One of the two mini TEPC was doped with 50 ppm of 10 B in order to simulate the BNC events occurring in BNCT. By properly processing the two microdosimetric spectra, the gamma, neutron and BNC spectral components can be derived with good precision (∼6%). However, direct measurements of 10 B in some doped plastic samples, which were used for constructing the cathode walls, point out the scarce accuracy of the nominal 10 B concentration value. The influence of the Boral ® door, which closes the irradiation channel, has been measured. The gamma dose increases significantly (+51%) when the Boral ® door is closed. The crypt-cell-regeneration weighting function has been used to measure the quality, namely the RBE µ value, of the radiation field in different conditions. The measured RBE µ values are only partially consistent with the RBE values of other BNCT facilities. - Highlights: • A counter with two mini TEPCs, both equipped with electrical-field guard tubes, has been constructed. • The microdosimetric spectrum of the LENA-reactor irradiation vane has been studied. • The radiation-field quality (RBE) assessment confirms that the D n /D tot ratio is not an accurate parameter to characterize the BNCT radiation field

  14. Value-based HR practices, i-deals and clinical error control with CSR as a moderator.

    Science.gov (United States)

    Luu, Tuan; Rowley, Chris; Siengthai, Sununta; Thanh Thao, Vo

    2017-05-08

    Purpose Notwithstanding the rising magnitude of system factors in patient safety improvement, "human factors" such as idiosyncratic deals (i-deals) which also contribute to the adjustment of system deficiencies should not be neglected. The purpose of this paper is to investigate the role of value-based HR practices in catalyzing i-deals, which then influence clinical error control. The research further examines the moderating role of corporate social responsibility (CSR) on the effect of value-based HR practices on i-deals. Design/methodology/approach The data were collected from middle-level clinicians from hospitals in the Vietnam context. Findings The research results confirmed the effect chain from value-based HR practices through i-deals to clinical error control with CSR as a moderator. Originality/value The HRM literature is expanded through enlisting i-deals and clinical error control as the outcomes of HR practices.

  15. Heavy particle clinical radiotherapy trial at Lawrence Berkeley Laboratory. Progress report, July 1975-July 1979

    International Nuclear Information System (INIS)

    Castro, J.R.

    1979-01-01

    The primary objectives of the clinical radiotherapy program are: to evaluate the potential of improved dose localization particularly as exemplified by helium ion irradiation; and to evaluate the combined potential of improved dose localization and increased biologic effect available with heavier ions such as carbon, neon, and argon. It was possible to make modifications rapidly to provide for large field, fractionated, Bragg peak irradiation at the 184-inch cyclotron with the helium ion beam. This allowed the opportunity to gain experience with charged particle irradiation treatment techniques, patient immobilization techniques, treatment planning and dosimetry studies including the utilization of CT scanning for tumor localization and charged particle dose distributions as well as beginning studies in compensating for tissue inhomogeneities in the beam path. These treatment techniques have been directly transferable to the Bevalac facility where a similar patient positioner has been installed for human irradiation with heavier particles. For the studies both with helium and now with heavier particles, patients with multiple skin and subcutaneous metastatic nodules for evaluation of skin RBE data and patients with locally advanced and/or unresectable tumors unlikely to be effectively treated by any conventional modality were sought. In order to facilitate intercomparison with megavoltage irradiation techniques, a conventional dose fractionation scheme has been adopted. A few exceptions to this dose specification scheme have been patients in which pulmonary, subcutaneous or skin nodules have been irradiated with larger fraction sizes ranging up to 400 rads per fraction in order to obtain clinical RBE studies in 8 to 10 fractions of heavy particles

  16. Reference values of clinical chemistry and hematology parameters in rhesus monkeys (Macaca mulatta).

    Science.gov (United States)

    Chen, Younan; Qin, Shengfang; Ding, Yang; Wei, Lingling; Zhang, Jie; Li, Hongxia; Bu, Hong; Lu, Yanrong; Cheng, Jingqiu

    2009-01-01

    Rhesus monkey models are valuable to the studies of human biology. Reference values for clinical chemistry and hematology parameters of rhesus monkeys are required for proper data interpretation. Whole blood was collected from 36 healthy Chinese rhesus monkeys (Macaca mulatta) of either sex, 3 to 5 yr old. Routine chemistry and hematology parameters, and some special coagulation parameters including thromboelastograph and activities of coagulation factors were tested. We presented here the baseline values of clinical chemistry and hematology parameters in normal Chinese rhesus monkeys. These data may provide valuable information for veterinarians and investigators using rhesus monkeys in experimental studies.

  17. Neutron and photon clonogenic survival curves of two chemotherapy resistant human intermediate-grade non-Hodgkin lymphoma cell lines

    International Nuclear Information System (INIS)

    Aref, Amr; Yudelev, Mark; Mohammad, Ramzi; Choudhuri, Rajani; Orton, Colin; Al-Katib, Ayad

    1999-01-01

    Background: The potential role of neutron therapy in the management of intermediate-grade non-Hodgkin lymphoma (IGNHL) has not been examined because of the belief that the anticipated radiobiological effectiveness (RBE) would be uniformly very low. Purpose: To determine the fast neutron RBE for two chemotherapy-resistant IGNHL cell lines. Methods and Materials: Conventional soft agar clonogenic survival curves following irradiation by 60 Co and fast neutron were established for two IGNHL cell lines. These cell lines, WSU-DLCL2 and SK-DHL2B, were found in previous studies to be able to repair sublethal damage, and were also resistant to L-Pam and doxorubicin chemotherapy. Results: When the surviving fraction after 2 Gy photon was chosen as the biological endpoint, the RBE for WSU-DLCL2 and SK-DHL2B measured 3.34 and 3.06. Similarly, when 10% survival was considered, the RBE for these two cell lines measured 2.54 and 2.59. The RBE, as measured by the ratios α neutron/α photon, for WSU-DLCL2, SK-DHL2B cell lines are 6.67 and 5.65, respectively. These results indicate that the RBE for these IGNHL cell lines is higher than the average RBE for cell lines of other histological types. Conclusion: Fast neutron irradiation may be of potential value in treating selected cases of IGNHL

  18. Clinical ethics and values: how do norms evolve from practice?

    Science.gov (United States)

    Spranzi, Marta

    2013-02-01

    Bioethics laws in France have just undergone a revision process. The bioethics debate is often cast in terms of ethical principles and norms resisting emerging social and technological practices. This leads to the expression of confrontational attitudes based on widely differing interpretations of the same principles and values, and ultimately results in a deadlock. In this paper I would like to argue that focusing on values, as opposed to norms and principles, provides an interesting perspective on the evolution of norms. As Joseph Raz has convincingly argued, "life-building" values and practices are closely intertwined. Precisely because values have a more indeterminate meaning than norms, they can be cited as reasons for action by concerned stakeholders, and thus can help us understand how controversial practices, e.g. surrogate motherhood, can be justified. Finally, norms evolve when the interpretations of the relevant values shift and cause a change in the presumptions implicit in the norms. Thus, norms are not a prerequisite of the ethical solution of practical dilemmas, but rather the outcome of the decision-making process itself. Struggling to reach the right decision in controversial clinical ethics situations indirectly causes social and moral values to change and principles to be understood differently.

  19. Dose to the Developing Dentition During Therapeutic Irradiation: Organ at Risk Determination and Clinical Implications

    International Nuclear Information System (INIS)

    Thompson, Reid F.; Schneider, Ralf A.; Albertini, Francesca; Lomax, Antony J.; Ares, Carmen; Goitein, Gudrun; Hug, Eugen B.

    2013-01-01

    Purpose: Irradiation of pediatric facial structures can cause severe impairment of permanent teeth later in life. We therefore focused on primary and permanent teeth as organs at risk, investigating the ability to identify individual teeth in children and infants and to correlate dose distributions with subsequent dental toxicity. Methods and Materials: We retrospectively reviewed 14 pediatric patients who received a maximum dose >20 Gy(relative biological effectiveness, RBE) to 1 or more primary or permanent teeth between 2003 and 2009. The patients (aged 1-16 years) received spot-scanning proton therapy with 46 to 66 Gy(RBE) in 23 to 33 daily fractions for a variety of tumors, including rhabdomyosarcoma (n=10), sarcoma (n=2), teratoma (n=1), and carcinoma (n=1). Individual teeth were contoured on axial slices from planning computed tomography (CT) scans. Dose-volume histogram data were retrospectively obtained from total calculated delivered treatments. Dental follow-up information was obtained from external care providers. Results: All primary teeth and permanent incisors, canines, premolars, and first and second molars were identifiable on CT scans in all patients as early as 1 year of age. Dose-volume histogram analysis showed wide dose variability, with a median 37 Gy(RBE) per tooth dose range across all individuals, and a median 50 Gy(RBE) intraindividual dose range across all teeth. Dental follow-up revealed absence of significant toxicity in 7 of 10 patients but severe localized toxicity in teeth receiving >20 Gy(RBE) among 3 patients who were all treated at <4 years of age. Conclusions: CT-based assessment of dose distribution to individual teeth is feasible, although delayed calcification may complicate tooth identification in the youngest patients. Patterns of dental dose exposure vary markedly within and among patients, corresponding to rapid dose falloff with protons. Severe localized dental toxicity was observed in a few patients receiving the

  20. Reference values for 27 clinical chemistry tests in 70-year-old males and females.

    Science.gov (United States)

    Carlsson, Lena; Lind, Lars; Larsson, Anders

    2010-01-01

    Reference values are usually defined based on blood samples from healthy men or nonpregnant women in the age range of 20-50 years. These values are not optimal for elderly patients, as many biological markers change over time and adequate reference values are important for correct clinical decisions. To validate NORIP (Nordic Reference Interval Project) reference values in a 70-year-old population. We studied 27 frequently used laboratory tests. The 2.5th and 97.5th percentiles for these markers were calculated according to the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values. Reference values are reported for plasma alanine aminotransferase, albumin, alkaline phosphatase, pancreas amylase, apolipoprotein A1, apolipoprotein B, aspartate aminotransferase, bilirubin, calcium, chloride, cholesterol, creatinine, creatine kinase, C-reactive protein, glucose, gamma-glutamyltransferase, HDL-cholesterol, iron, lactate dehydrogenase, LDL-cholesterol, magnesium, phosphate, potassium, sodium, transferrin, triglycerides, urate and urea. Reference values calculated from the whole population and a subpopulation without cardiovascular disease showed strong concordance. Several of the reference interval limits were outside the 90% CI of a Scandinavian population (NORIP). 2009 S. Karger AG, Basel.

  1. The relative biological effectiveness of out-of-field dose

    International Nuclear Information System (INIS)

    Balderson, Michael; Koger, Brandon; Kirkby, Charles

    2016-01-01

    Purpose: using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. Materials and methods: using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. Results: spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. Conclusions: spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions. (paper)

  2. Evaluation of clinical value of serum CA19-9

    International Nuclear Information System (INIS)

    Lv Haifeng; Lin Zhiyu; Lu Xiaozhuo; Chen Yini

    2003-01-01

    The article is to study the clinical significance of serum CA19-9 in diagnosing malignant tumor occurred in digestive system and to select cut off values for differentiating diagnosis of a pancreatic neoplasms and pancreatitis. Using chemiluminescence immunoassay, serum CA19-9 level of below subjects were analyzed: control group (n=21); digestive system neoplasm group (n=125, with 7 cases conformed as pancreatic cancer); non-neoplastic disease group (n=387, with 15 cases conformed as pancreatitis secondary to destructive cholangitis). Receiver operating characteristic (ROC) curve was used for analyzing results and selecting cut off values. When cut off value was 18.4 kU/L, sensibility for conforming a digestive system neoplasm was 60.8%, while its related specificity against control group and non-neoplastic disease group was 95. 2% and 68.2%, respectively. Sensibility for diagnosing pancreatic neoplasm was 85.7%, while its related specificity against control group and non-pancreatic origin tumor group was 95.0% and 63.1%, respectively. When 37 kU/L was chosen as cut off value, specificity for differentiating diagnosis of pancreatic neoplasm and pancreatitis secondary to destructive cholangitis rose from 13.3% to 46.7%. Serum CA19-9 could be used as an aid in detecting digestive system neoplastic disease; it is a reliable marker for pancreatic neoplasm. Raising cut off value may help to differentiate pancreatic neoplasm and pancreatitis secondary to destructive cholangitis

  3. Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

    International Nuclear Information System (INIS)

    Leith, J.L.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Walton, R.E.; Woodruff, K.H.; Howard, J.

    1980-01-01

    The response of rat spinal cord to irradiation with accelerated heavy ions, in particular carbon and neon ions has been studied. Two different ionization regions in the modified Bragg curve for each ion have been studied for both single and fractionated exposures. We have defined the paralytic response as a function of dose and dose per fraction, and we have determined RBE and repair values. The response of rat spinal cord is both dose and LET dependent, which allows the derivation of RBE and repair values

  4. The clinical value of serum PSA and PAP determinations in prostate cancer patients

    International Nuclear Information System (INIS)

    Zeng Lei; Yu Renbo; Du Guowei; Pang Baozhong

    2001-01-01

    Objective: To investigate the clinical value of serum PSA and PAP determinations in diagnosis of prostate cancer patients. Methods: The serum PSA and PAP levels of 98 prostate cancer patients, 45 prostate benign disease patients and 40 normal subjects were tested by IRMA. Results: The serum PSA and PAP levels of prostate cancer patients were significantly higher than those in prostate benign disease patients and normal controls (P < 0.01). The diagnostic sensitivity and specificity of serum PSA for prostate cancer were 93.9% and 93.3% respectively. The diagnostic sensitivity and specificity of serum PAP for prostate cancer were 71.4% and 91.1% respectively. Conclusion: The determination of serum PSA and PAP was of high clinical value for diagnosis of early prostate cancer. It could be used as an important reference parameter for the clinical staging, follow-up of treatment result and prediction of prognosis

  5. The clinical value of planar thallium-201 myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Niemeyer, M.G.

    1989-01-01

    The clinical value of planar thalium-201 myocardial perfusion scintigraphy was examined, using visual and quantitative analysis, for the detection of presence, localization and extent of coronary disease, using coronary arteriography as gold standard. The indremental diagnostic yield of different noninvasive tests for the diagnosis and the severity of coronary artery disease was quantified by using multivariate discriminant analysis. (author). 284 refs.; 14 figs.; 37 tabs

  6. Determining utility values in patients with anterior cruciate ligament tears using clinical scoring systems

    Directory of Open Access Journals (Sweden)

    Szucs Thomas

    2011-08-01

    Full Text Available Abstract Background Several instruments and clinical scoring systems have been established to evaluate patients with ligamentous knee injuries. A comparison of individual articles in the literature is challenging, not only because of heterogeneity in methodology, but also due to the variety of the scoring systems used to document clinical outcomes. There is limited information about the correlation between used scores and quality of life with no information being available on the impact of each score on the utility values. The aim of this study was to compare the most commonly used scores for evaluating patients with anterior cruciate ligament (ACL injuries, and to establish corresponding utility values. These values will be used for the interpretation and comparison of outcome results in the currently available literature for different treatment options. Methods Four hypothetical vignettes were defined, based on different levels of activities after rupture of the ACL to simulate typical situations seen in daily practice. A questionnaire, including the Health Utility Index (HUI for utility values, the IKDC subjective score, the Lysholm and the Tegner score, was created and 25 orthopedic surgeons were asked to fill the questionnaire for each hypothetical patient as proxies for all patients they had treated and who would fit in that hypothetical vignette. Results The utility value as an indicator for quality of life increased with the level of activity. Having discomforts already during normal activities of daily living was rated with a mean utility value of 0.37 ± 0.19, half of that of a situation where mild sport activity was possible without discomfort (0.78 ± 0.11. All investigated scores were able to distinguish clearly (p Conclusions Here we report the correlation between the most commonly used scores for the assessment of patients with a ruptured ACL and utility values as an indicator of quality of life. Assumptions were based on expert

  7. [Research progress on the clinical value of Ki-67 in breast cancer and its cut-off definition].

    Science.gov (United States)

    Chen, Qing; Wu, Kejin

    2015-08-01

    Ki-67 has an important application value in clinical practice. However, it is still a little tough in clinical application because of the debate on the cut-off definition of Ki-67 index. This review summarizes most studies on the prognostic and predictive value of Ki-67, analyzes the reasons for the discrepancies among the studies cited, and presents the necessity and clinical significance of scientifically defining the cut-off of Ki-67 index, providing a theoretical basis for Ki-67 in clinical application.

  8. Monetary Value of a Prescription Assistance Program Service in a Rural Family Medicine Clinic

    Science.gov (United States)

    Whitley, Heather P.

    2011-01-01

    Purpose: To quantify the monetary value of medications provided to rural Alabamians through provision of pharmaceutical manufacturer-sponsored prescription assistance programs (PAPs) provided by a clinical pharmacist in a private Black Belt family medicine clinic during 2007 and 2008. Methods: Patients struggling to afford prescription medications…

  9. WE-FG-BRB-03: Challenges and Opportunities for Implementing Biological Optimization in Particle Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, D. [Yale University School of Medicine (United States)

    2016-06-15

    The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences between particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to

  10. Evaluating Business Value of IT in Healthcare: Three Clinical Practices from Australia and the US.

    Science.gov (United States)

    Haddad, Peter; Schaffer, Jonathan L; Wickramasinghe, Nilmini

    2015-01-01

    Exponentially increasing costs in healthcare coupled with poor quality and limited access have motivated the healthcare industry to turn to IS/IT solutions to overcome these issues and facilitate superior healthcare delivery. In an environment of rapid development of new clinical informatics solutions claiming to provide better healthcare delivery, there is a paucity of systematic frameworks to robustly measure the actual value of these systems. The promised business value of these solutions has been elusive; hence, this study offers an approach for the evaluation of the business value of health IS/IT solutions based on a conceptual model, which has been validated using three clinical case studies.

  11. MO-FG-CAMPUS-TeP3-02: Benchmarks of a Proton Relative Biological Effectiveness (RBE) Model for DNA Double Strand Break (DSB) Induction in the FLUKA, MCNP, TOPAS, and RayStation™ Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R [University of Washington, Seattle, WA (United States); Streitmatter, S [University of Utah Hospitals, Salt Lake City, UT (United States); Traneus, E [RAYSEARCH LABORATORIES AB, Stockholm (Sweden); Moskvin, V [St. Jude Children’s Hospital, Memphis, TN (United States); Schuemann, J [Massachusetts General Hospital, Boston, MA (United States)

    2016-06-15

    Purpose: Validate implementation of a published RBE model for DSB induction (RBEDSB) in several general purpose Monte Carlo (MC) code systems and the RayStation™ treatment planning system (TPS). For protons and other light ions, DSB induction is a critical initiating molecular event that correlates well with the RBE for cell survival. Methods: An efficient algorithm to incorporate information on proton and light ion RBEDSB from the independently tested Monte Carlo Damage Simulation (MCDS) has now been integrated into MCNP (Stewart et al. PMB 60, 8249–8274, 2015), FLUKA, TOPAS and a research build of the RayStation™ TPS. To cross-validate the RBEDSB model implementation LET distributions, depth-dose and lateral (dose and RBEDSB) profiles for monodirectional monoenergetic (100 to 200 MeV) protons incident on a water phantom are compared. The effects of recoil and secondary ion production ({sub 2}H{sub +}, {sub 3}H{sub +}, {sub 3}He{sub 2+}, {sub 4}He{sub 2+}), spot size (3 and 10 mm), and transport physics on beam profiles and RBEDSB are examined. Results: Depth-dose and RBEDSB profiles among all of the MC models are in excellent agreement using a 1 mm distance criterion (width of a voxel). For a 100 MeV proton beam (10 mm spot), RBEDSB = 1.2 ± 0.03 (− 2–3%) at the tip of the Bragg peak and increases to 1.59 ± 0.3 two mm distal to the Bragg peak. RBEDSB tends to decrease as the kinetic energy of the incident proton increases. Conclusion: The model for proton RBEDSB has been accurately implemented into FLUKA, MCNP, TOPAS and the RayStation™TPS. The transport of secondary light ions (Z > 1) has a significant impact on RBEDSB, especially distal to the Bragg peak, although light ions have a small effect on (dosexRBEDSB) profiles. The ability to incorporate spatial variations in proton RBE within a TPS creates new opportunities to individualize treatment plans and increase the therapeutic ratio. Dr. Erik Traneus is employed full-time as a Research Scientist

  12. Survival of parenchymal hepatocytes exposed to 14.3-MeV neutrons

    International Nuclear Information System (INIS)

    Jirtle, R.L.; Gould, M.N.; DeLuca, P.M. Jr.; Pearson, D.W.

    1982-01-01

    This report presents the results of the measurement of a dose survival curve and RBE values for rat hepatic cells irradiated in vivo with 14.3 MeV neutrons. The purpose was to determine the RBE for neutrons as a function of dose, and whether hepatocytes exposed to neutrons are as efficient at repairing potentially lethal damage as they are after exposure to low LET radiation

  13. The cultural shaping of alexithymia: values and externally oriented thinking in a Chinese clinical sample.

    Science.gov (United States)

    Dere, Jessica; Tang, Qiuping; Zhu, Xiongzhao; Cai, Lin; Yao, Shuqiao; Ryder, Andrew G

    2013-05-01

    Alexithymia is a multi-faceted personality construct characterized by difficulties in identifying and describing emotional states. Originally based on observations of American psychosomatic patients, the construct is now studied in a variety of cultural contexts. However, few studies have critically examined alexithymia from a cultural perspective. Dere et al. [1] recently found support for the hypothesis that one alexithymia component - externally oriented thinking (EOT) - is linked to cultural values, among Euro-Canadian and Chinese-Canadian students. The current study examines this association in a Chinese clinical sample. Outpatients presenting at three hospital-based psychology clinics in Hunan province, China (N=268) completed a structured clinical interview and self-report measures of alexithymia and cultural values. All participants endorsed clinically significant levels of depressed mood, anhedonia, and/or fatigue. As expected, EOT was negatively predicted by Modernization and Euro-American values. Two other alexithymia components, difficulty identifying feelings and difficulty describing feelings, were unrelated to cultural values. These findings suggest that cultural variations in the importance placed on emotional experience must be taken into account in cross-cultural alexithymia research. Such studies should also consider separately the specific components of alexithymia; failure to do so can lead to overestimation of alexithymia in groups where scores are driven by culturally-promoted EOT. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Aligning clinical compensation with clinical productivity: design and implementation of the financial value unit (FVU) system in an academic department of internal medicine.

    Science.gov (United States)

    Stites, Steven; Steffen, Patrick; Turner, Scott; Pingleton, Susan

    2013-07-01

    A new metric was developed and implemented at the University of Kansas School of Medicine Department of Internal Medicine, the financial value unit (FVU). This metric analyzes faculty clinical compensation compared with clinical work productivity as a transparent means to decrease the physician compensation variability and compensate faculty equitably for clinical work.The FVU is the ratio of individual faculty clinical compensation compared with their total work relative value units (wRVUs) generated divided by Medical Group Management Association (MGMA) salary to wRVUs of a similar MGMA physician.The closer the FVU ratio is to 1.0, the closer clinical compensation is to that of an MGMA physician with similar clinical productivity. Using FVU metrics to calculate a faculty salary gap compared with MGMA median salary and wRVU productivity, a divisional production payment was established annually.From FY 2006 to FY 2011, both total faculty numbers and overall clinical activity increased. With the implementation of the FVU, both clinical productivity and compensation increased while, at the same time, physician retention rates remained high. Variability in physician compensation decreased. Dramatic clinical growth was associated with the alignment of clinical work and clinical compensation in a transparent and equable process.

  15. Optimising the clinical strategy for autoimmune liver diseases: Principles of value-based medicine.

    Science.gov (United States)

    Carbone, Marco; Cristoferi, Laura; Cortesi, Paolo Angelo; Rota, Matteo; Ciaccio, Antonio; Okolicsanyi, Stefano; Gemma, Marta; Scalone, Luciana; Cesana, Giancarlo; Fabris, Luca; Colledan, Michele; Fagiuoli, Stefano; Ideo, Gaetano; Belli, Luca Saverio; Munari, Luca Maria; Mantovani, Lorenzo; Strazzabosco, Mario

    2018-04-01

    Autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis represent the three major autoimmune liver diseases (AILDs). Their management is highly specialized, requires a multidisciplinary approach and often relies on expensive, orphan drugs. Unfortunately, their treatment is often unsatisfactory, and the care pathway heterogeneous across different centers. Disease-specific clinical outcome indicators (COIs) able to evaluate the whole cycle of care are needed to assist both clinicians and administrators in improving quality and value of care. Aim of our study was to generate a set of COIs for the three AILDs. We then prospectively validated these indicators based on a series of consecutive patients recruited at three tertiary clinical centers in Lombardy, Italy. In phase I using a Delphi method and a RAND 9-point appropriateness scale a set of COIs was generated. In phase II the indicators were applied in a real-life dataset. Two-hundred fourteen patients were enrolled and followed-up for a median time of 54months and the above COIs were recorded using a web-based electronic medical record program. The COIs were easy to collect in the clinical practice environment and their values compared well with the available natural history studies. We have generated a comprehensive set of COIs which sequentially capture different clinical outcome of the three AILDs explored. These indicators represent a critical tool to implement a value-based approach to patients with these conditions, to monitor, compare and improve quality through benchmarking of clinical performance and to assess the significance of novel drugs and technologies. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen. Copyright © 2017. Published by Elsevier B.V.

  16. The relative biological effectiveness for carbon and oxygen ion beams using the raster-scanning technique in hepatocellular carcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Daniel Habermehl

    Full Text Available BACKGROUND: Aim of this study was to evaluate the relative biological effectiveness (RBE of carbon (12C and oxygen ion (16O-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation. METHODS: Four human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ion-single doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O. SOBP-penetration depth and extension was 35 mm +/-4 mm and 36 mm +/-5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and relative biological effectiveness (RBE values were defined. RESULTS: For all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1-3.3 and 1.9-3.1 for 12C and 16O, respectively. CONCLUSION: Both irradiation with 12C and 16O using the raster-scanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

  17. Screening for Binge Eating Disorders Using the Patient Health Questionnaire in a Community Sample

    Science.gov (United States)

    Striegel-Moore, Ruth H.; Perrin, Nancy; DeBar, Lynn; Wilson, G. Terence; Rosselli, Francine; Kraemer, Helena C.

    2009-01-01

    Objective To examine the operating characteristics of the Patient Health Questionnaire eating disorder module (PHQ-ED) for identifying bulimia nervosa/binge eating disorder (BN/BED) or recurrent binge eating (RBE) in a community sample, and to compare true positive (TP) versus false positive (FP) cases on clinical validators. Method 259 screen positive individuals and a random sample of 89 screen negative cases completed a diagnostic interview. Sensitivity, specificity, and Positive Predictive Value (PPV) were calculated. TP and FP cases were compared using t-tests and Chi-Square tests. Results The PHQ-ED had high sensitivity (100%) and specificity (92%) for detecting BN/BED or RBE, but PPV was low (15% or 19%). TP and FP cases did not differ significantly on frequency of subjective bulimic episodes, objective overeating, restraint, on BMI, and on self-rated health. Conclusions The PHQ-ED is recommended for use in large populations only in conjunction with follow-up questions to rule out cases without objective bulimic episodes. PMID:19424976

  18. Biological effectiveness of pulsed and continuous neutron radiation for cells of yeast Saccharomyces

    International Nuclear Information System (INIS)

    Tsyb, T.S.; Komarova, E.V.; Potetnya, V.I.; Obaturov, G.M.

    2001-01-01

    Data are presented on biological effectiveness of fast neutrons generated by BR-10 reactor (dose rate up to 3.8 Gy/s) in comparison with neutrons of pulsed BARS-6 reactor (dose rate ∼6x10 6 Gy/s) for yeast Saccharomyces vini cells of a wild type Menri 139-B and radiosensitive Saccharomyces cerevisiae (rad52/rad52; rad54/rad54) mutants which are defective over different systems of DNA reparation. Value of relative biological efficiency (RBE) of continuous radiation for wild stam is from 3.5 up to 2.5 when survival level being 75-10 %, and RBE of pulsed neutron radiation is in the limits of 2.0-1.7 at the same levels. For mutant stam the value of RBE (1.4-1.6) of neutrons is constant at all survival levels and does not depend on dose rate [ru

  19. The use of reference change values in clinical laboratories.

    Science.gov (United States)

    Bugdayci, Guler; Oguzman, Hamdi; Arattan, Havva Yasemin; Sasmaz, Guler

    2015-01-01

    The use of Reference Change Values (RCV) has been advocated as very useful for monitoring individuals. Most of these are performed for monitoring individuals in acute situations and for following up the improvement or deterioration of chronic diseases. In our study, we aimed at evaluating the RCV calculation for 24 clinical chemistry analytes widely used in clinical laboratories and the utilization of this data. Twenty-four serum samples were analyzed with Abbott kits (Abbott Laboratories, Abbott Park, IL, USA), manufactured for use with the Architect c8000 (Abbott Laboratories, Abbott Park, IL, USA) auto-analyzer. We calculated RCV using the following formula: RCV = Z x 2 1/2x (CVA2 + CVw2)1/2. Four reference change values (RCV) were calculated for each analyte using four statistical probabilities (0.95, and 0.99, unidirectional and bidirectional). Moreover, by providing an interval after identifying upper and lower limits with the Reference Change Factor (RCF), serially measured tests were calculated by using two formulas: exp (Z x 2 1/2 x (CV(A)2 + CVw2)½/100) for RCF(UP) and (1/RCF(UP)) for RCF(DOWN). RCVs of these analytes were calculated as 14.63% for glucose, 29.88% for urea, 17.75% for ALP, 53.39% for CK, 46.98% for CK-MB, 21.00% amylase, 8.00% for total protein, 8.70% for albumin, 51.08% for total bilirubin, 86.34% for direct bilirubin, 6.40% for calcium, 15.03% for creatinine, 21.47% for urate, 14.19% for total cholesterol, 46.62% for triglyceride, 20.51% for HDL-cholesterol, 29.59% for AST, 46.31% for ALT, 31.54% for GGT, 20.92% for LDH, 19.75% for inorganic phosphate, 3.05% for sodium, 11.75% for potassium, 4.44% for chloride (RCV, p laboratories. RCV could be available as a tool for making clinical decision, especially when monitoring individuals.

  20. Selection of carbon beam therapy: biophysical models of carbon beam therapy.

    Science.gov (United States)

    Matsufuji, Naruhiro

    2018-03-01

    Variation in the relative biological effectiveness (RBE) within the irradiation field of a carbon beam makes carbon-ion radiotherapy unique and advantageous in delivering the therapeutic dose to a deep-seated tumor, while sparing surrounding normal tissues. However, it is crucial to consider the RBE, not only in designing the dose distribution during treatment planning, but also in analyzing the clinical response retrospectively. At the National Institute of Radiological Sciences, the RBE model was established based on the response of human salivary gland cells. The response was originally handled with a linear-quadratic model, and later with a microdosimetric kinetic model. Retrospective analysis with a tumor-control probability model of non-small cell cancer treatment revealed a steep dose response in the tumor, and that the RBE of the tumor was adequately estimated using the model. A commonly used normal tissue complication probability model has not yet fully been accountable for the variable RBE of carbon ions; however, analysis of rectum injury after prostate cancer treatment suggested a highly serial-organ structure for the rectum, and a steep dose response similar to that observed for tumors.

  1. Faithful but Different: Clinical Social Workers Speak Out about Career Motivation and Professional Values

    Science.gov (United States)

    Bradley, Carolyn; Maschi, Tina; O'Brien, Helen; Morgen, Keith; Ward, Kelly

    2012-01-01

    The purpose of this study was to describe licensed clinical social workers' (LCSWs) professional motivation to pursue a social work career and the decision to enter clinical practice. It used a probability sample of 245 New Jersey LCSWs and the Social Work Values Survey as part of an anonymous self-administered mail survey. Descriptive analyses…

  2. Overview of research and therapy facilities for radiobiological experimental work in particle therapy. Report from the European Particle Therapy Network radiobiology group.

    Science.gov (United States)

    Dosanjh, Manjit; Jones, Bleddyn; Pawelke, Jörg; Pruschy, Martin; Sørensen, Brita Singers

    2018-04-24

    Particle therapy (PT) as cancer treatment, using protons or heavier ions, can provide a more favorable dose distribution compared to X-rays. While the physical characteristics of particle radiation have been the aim of intense research, less focus has been placed on the actual biological responses arising from particle irradiation. One of the biggest challenges for proton radiobiology is the RBE, with an increasing concern that the clinically-applied generic RBE-value of 1.1 is an approximation, as RBE is a complex quantity, depending on both biological and physical parameters, such as dose, LET, cellular and tissue radiobiological characteristics, as well as the endpoints being studied. Most of the available RBE data derive from in vitro experiments, with very limited in vivo data available, especially in late-reacting tissues, which provide the main constraints and influence the quality of life endpoints in radiotherapy. There is a need for systematic, large-scale studies to thoroughly establish the biology of particle radiation in a number of different experimental models in order to refine biophysical mathematical models that can potentially be used to guide PT. The overall objective of the European Particle Therapy Network (EPTN) WP6 is to form a network of research and therapy facilities in order to coordinate and standardize the radiobiological experiments, to obtain more accurate predictive parameters than in the past. Coordinated research is required in order to obtain the most appropriate experimental data. The aim in this paper is to describe the available radiobiology infrastructure of the centers involved in EPTN WP6. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Study of radiation-induced chromosomal aberrations

    International Nuclear Information System (INIS)

    Wolfring, E.

    2004-06-01

    A method for determining chromosomal aberrations was established for the purpose of examining the relative biological effectiveness (RBE) of photon radiation with respect to mammary epithelium cells. Cells were exposed to 25 kV X-radiation and to 200 kV X-radiation for comparison and the resulting concentrations of chromosomal aberrations were compared. The RBE M value for radiation-induced fragmentation was found to be 4.2 ± 2.4, while the RBE M value for radiation-induced generation of dicentric chromosomes was found to be 0.5 ± 0.5. In addition to the evaluation of chromosomal aberrations the number of cell cycles undergone by the cells was monitored by means of BrDU staining. As expected, the proportion of cells which underwent more than one cell cycle following exposure to 5 Gy was very low in both cases, amounting to 1.9% (25 kV) and 3.2 (200 kV). Non-radiated cells yielded control values of 26.0% and 12.6%, suggesting variations in external conditions from day to day

  4. Study of radiation-induced chromosomal aberrations; Untersuchung strahleninduzierter Chromosomenaberrationen. Bestrahlung der Brustdruesenepithelzelllinie MCF-12A mit Roentgenstrahlung aus konventionellen Roentgenroehren und Bestimmung der Dosis-Effekt-Kurve. Studienarbeit

    Energy Technology Data Exchange (ETDEWEB)

    Wolfring, E. [Technische Univ. Bergakademie Freiberg (Germany). Interdisziplinaeres Oekologisches Zentrum

    2004-06-01

    A method for determining chromosomal aberrations was established for the purpose of examining the relative biological effectiveness (RBE) of photon radiation with respect to mammary epithelium cells. Cells were exposed to 25 kV X-radiation and to 200 kV X-radiation for comparison and the resulting concentrations of chromosomal aberrations were compared. The RBE{sub M} value for radiation-induced fragmentation was found to be 4.2 {+-} 2.4, while the RBE{sub M} value for radiation-induced generation of dicentric chromosomes was found to be 0.5 {+-} 0.5. In addition to the evaluation of chromosomal aberrations the number of cell cycles undergone by the cells was monitored by means of BrDU staining. As expected, the proportion of cells which underwent more than one cell cycle following exposure to 5 Gy was very low in both cases, amounting to 1.9% (25 kV) and 3.2 (200 kV). Non-radiated cells yielded control values of 26.0% and 12.6%, suggesting variations in external conditions from day to day.

  5. Diagnostic value of patient characteristics, history, and six clinical tests for traumatic anterior shoulder instability

    NARCIS (Netherlands)

    van Kampen, D.A.; van den Berg, T.; van der Woude, H.J.; Castelein, R.M.; Terwee, C.B.; Willems, W.J.

    2013-01-01

    Background: It is unknown which combination of patient information and clinical tests might beoptimal for the diagnosis of traumatic anterior shoulder instability. This study aimed to determinethe diagnostic value of individual clinical tests and to develop a prediction model that combined patient

  6. Clinical chemistry reference values for 75-year-old apparently healthy persons.

    Science.gov (United States)

    Huber, Klaus Roland; Mostafaie, Nazanin; Stangl, Gerhard; Worofka, Brigitte; Kittl, Eva; Hofmann, Jörg; Hejtman, Milos; Michael, Rainer; Weissgram, Silvia; Leitha, Thomas; Jungwirth, Susanne; Fischer, Peter; Tragl, Karl-Heinz; Bauer, Kurt

    2006-01-01

    Clinical chemistry reference values for elderly persons are sparse and mostly intermixed with those for younger subjects. To understand the links between metabolism and aging, it is paramount to differentiate between "normal" physiological processes in apparently healthy elderly subjects and metabolic changes due to long-lasting diseases. The Vienna Transdanube Aging (VITA) study, which began in 2000 and is continuing, will allow us to do just that, because more than 600 male and female volunteers aged exactly 75 years (to exclude any influence of the "aging" factor in this cohort) are participating in this study. Extensive clinical, neurological, biochemical, psychological, genetic, and radiological analyses, with a special emphasis on consumption of medication and abuse of drugs, were performed on each of the probands. The multitude of data and questionnaires obtained made possible an a posteriori approach to select individuals fulfilling criteria for a reference sample group of apparently healthy 75-year-old subjects for our study. Specific analytes were quantified on automated clinical analyzers, while manual methods were used for hormonal analytes. All clinical chemistry analytes were evaluated using in-depth statistical analyses with SPSS for Windows. In all, reference intervals for 45 analytes could be established. These include routine parameters for the assessment of organ functions, as well as hormone concentrations and hematological appraisals. Because all patients were reevaluated after exactly 30 months in the course of this study, we had the opportunity to reassess their health status at the age of 77.5 years. This was very useful for validation of the first round data set. Data of the second round evaluation corroborate the reference limits of the baseline analysis and further confirm our inclusion and exclusion criteria. In summary, we have established a reliable set of reference data for hormonal, hematological, and clinical chemistry analytes for

  7. Challenges in the Clinical Application of the American Society of Clinical Oncology Value Framework: A Medicare Cost-Benefit Analysis in Chronic Lymphocytic Leukemia.

    Science.gov (United States)

    Seymour, Erlene K; Schiffer, Charles A; de Souza, Jonas A

    2017-12-01

    The ASCO Value Framework calculates the value of cancer therapies. Given costly novel therapeutics for chronic lymphocytic leukemia, we used the framework to compare net health benefit (NHB) and cost within Medicare of all regimens listed in the National Comprehensive Cancer Network (NCCN) guidelines. The current NCCN guidelines for chronic lymphocytic leukemia were reviewed. All referenced studies were screened, and only randomized controlled prospective trials were included. The revised ASCO Value Framework was used to calculate NHB. Medicare drug pricing was used to calculate the cost of therapies. Forty-nine studies were screened. The following observations were made: only 10 studies (20%) could be evaluated; when comparing regimens studied against the same control arm, ranking NHB scores were comparable to their preference in guidelines; NHB scores varied depending on which variables were used, and there were no clinically validated thresholds for low or high values; treatment-related deaths were not weighted in the toxicity scores; and six of the 10 studies used less potent control arms, ranked as the least-preferred NCCN-recommended regimens. The ASCO Value Framework is an important initial step to quantify value of therapies. Essential limitations include the lack of clinically relevant validated thresholds for NHB scores and lack of incorporation of grade 5 toxicities/treatment-related mortality into its methodology. To optimize its application for clinical practice, we urge investigators/sponsors to incorporate and report the required variables to calculate the NHB of regimens and encourage trials with stronger comparator arms to properly quantify the relative value of therapies.

  8. Dosimetry and radiobiology of negative pions and heavy ions

    International Nuclear Information System (INIS)

    Raju, M.R.

    1978-01-01

    The depth dose distribution of pion beams has not been found superior to protons. Pion radiation quality at the plateau region is comparable to conventional low-LET radiations, and radiobiology results also indicate RBE values close to unity. In the pion stopping region, the radiation quality increases considerably. Radiobiology data for negative pions at the Bragg peak position clearly indicate the increase in RBE and the reduction in OER. Even at the Bragg peak position, compared to fast neutrons, the average LET of negative pions is lower. Pion radiobiology data have indicated lower RBE values and higher OER values compared to fast neutrons. The radiation quality of fast neutrons is in between that of carbon and neon ions at the peak region and that of neon ions at the plateau is lower than for fast neutrons. The mean LET value for helium ions, even at the distal end of the peak, is lower than for fast neutrons. Dose localization of heavy ions has been found to decrease slowly with increasing charge of the heavy ion. The intercellular contact that protects cells after exposure to low-LET radiations is not detected after exposure to heavy ions. Single and fractionated doses of heavy ions produce dose-response curves for heavy ions having reduced shoulders but similar slopes when compared to gamma rays. Fractionated treatments of heavy ions produce an enhanced effect in the peak region compared to the plateau region and could lead to a substantial gain in therapeutic ratio. The OER for protons was similar to that for x rays. The OER values for negative pions, helium ions, and carbon ions were larger, for neon ions similar, and for argon ions smaller when compared to fast neutrons.Negative pions, helium ions, and carbon ions may be very effective clinically because the radiation quality of these beams is similar to that of the mixed scheme of neutrons and x rays

  9. Clinical Outcomes and Late Endocrine, Neurocognitive, and Visual Profiles of Proton Radiation for Pediatric Low-Grade Gliomas

    International Nuclear Information System (INIS)

    Greenberger, Benjamin A.; Pulsifer, Margaret B.; Ebb, David H.; MacDonald, Shannon M.; Jones, Robin M.; Butler, William E.; Huang, Mary S.; Marcus, Karen J.; Oberg, Jennifer A.; Tarbell, Nancy J.; Yock, Torunn I.

    2014-01-01

    Purpose/Objective(s): Primary low-grade gliomas are common brain tumors of childhood, many of which require radiation therapy (RT) as definitive treatment. Increased conformality of RT could decrease the incidence and severity of late effects. We report our experience with 32 pediatric patients treated with proton RT. Methods and Materials: Thirty-two pediatric patients with low-grade gliomas of the brain or spinal cord were treated with proton RT from 1995 to 2007. Sixteen patients received at least 1 regimen of chemotherapy before definitive RT. The median radiation dose was 52.2 Gy RBE (48.6-54 Gy RBE ). Results: The median age at treatment was 11.0 years (range, 2.7-21.5 years), with a median follow-up time of 7.6 years (range, 3.2-18.2 years). The 6-year and 8-year rates of progression-free survival were 89.7% and 82.8%, respectively, with an 8-year overall survival of 100%. For the subset of patients who received serial neurocognitive testing, there were no significant declines in Full-Scale Intelligence Quotient (P=.80), with a median neurocognitive testing interval of 4.5 years (range, 1.2-8.1 years) from baseline to follow-up, but subgroup analysis indicated some significant decline in neurocognitive outcomes for young children (<7 years) and those with significant dose to the left temporal lobe/hippocampus. The incidence of endocrinopathy correlated with a mean dose of ≥40 Gy RBE to the hypothalamus, pituitary, or optic chiasm. Stabilization or improvement of visual acuity was achieved in 83.3% of patients at risk for radiation-induced injury to the optic pathways. Conclusions: This report of late effects in children with low-grade gliomas after proton RT is encouraging. Proton RT appears to be associated with good clinical outcome, especially when the tumor location allows for increased sparing of the left temporal lobe, hippocampus, and hypothalamic-pituitary axis

  10. Clinical Outcomes and Late Endocrine, Neurocognitive, and Visual Profiles of Proton Radiation for Pediatric Low-Grade Gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, Benjamin A. [Harvard Medical School, Boston, Massachusetts (United States); Pulsifer, Margaret B. [Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts (United States); Ebb, David H. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); MacDonald, Shannon M. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Jones, Robin M. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts (United States); Butler, William E. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Huang, Mary S. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Marcus, Karen J. [Department of Radiation Oncology, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Oberg, Jennifer A. [Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York (United States); Tarbell, Nancy J. [Harvard Medical School, Boston, Massachusetts (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-08-01

    Purpose/Objective(s): Primary low-grade gliomas are common brain tumors of childhood, many of which require radiation therapy (RT) as definitive treatment. Increased conformality of RT could decrease the incidence and severity of late effects. We report our experience with 32 pediatric patients treated with proton RT. Methods and Materials: Thirty-two pediatric patients with low-grade gliomas of the brain or spinal cord were treated with proton RT from 1995 to 2007. Sixteen patients received at least 1 regimen of chemotherapy before definitive RT. The median radiation dose was 52.2 Gy{sub RBE} (48.6-54 Gy{sub RBE}). Results: The median age at treatment was 11.0 years (range, 2.7-21.5 years), with a median follow-up time of 7.6 years (range, 3.2-18.2 years). The 6-year and 8-year rates of progression-free survival were 89.7% and 82.8%, respectively, with an 8-year overall survival of 100%. For the subset of patients who received serial neurocognitive testing, there were no significant declines in Full-Scale Intelligence Quotient (P=.80), with a median neurocognitive testing interval of 4.5 years (range, 1.2-8.1 years) from baseline to follow-up, but subgroup analysis indicated some significant decline in neurocognitive outcomes for young children (<7 years) and those with significant dose to the left temporal lobe/hippocampus. The incidence of endocrinopathy correlated with a mean dose of ≥40 Gy{sub RBE} to the hypothalamus, pituitary, or optic chiasm. Stabilization or improvement of visual acuity was achieved in 83.3% of patients at risk for radiation-induced injury to the optic pathways. Conclusions: This report of late effects in children with low-grade gliomas after proton RT is encouraging. Proton RT appears to be associated with good clinical outcome, especially when the tumor location allows for increased sparing of the left temporal lobe, hippocampus, and hypothalamic-pituitary axis.

  11. A comparison of the potential therapeutic gain of p(66)/Be neutrons and d(14)/Be neutrons

    International Nuclear Information System (INIS)

    Slabbert, Jacobus P.; Theron, Therina; Zoelzer, Friedo; Streffer, Christian; Boehm, Lothar

    2000-01-01

    neutron RBE on photon sensitivity. The increase of RBE with photon resistance is more pronounced in the low-energy Essen neutrons than in the high-energy Faure neutrons. An RBE advantage is indicated for photon-resistant cell lines and this is particularly apparent in the low-dose range using α-coefficients as compared to the mean inactivation dose. The clinical application of low-energy neutrons may be more restricted because of poor penetration and lack of skin sparing. However, these neutrons discriminate better between photon-sensitive and photon-resistant cells giving an RBE range of 2-6 and a mean RBE of 4.1, than high-energy neutrons where the RBE range is 1.6-3.5 and the mean RBE is 2.4. From the radiobiological point of view it, therefore, appears that the clinical potential of low-energy neutrons is considerably underrated

  12. Exploring the Educational Value of Clinical Vignettes from the Society of General Internal Medicine National Meeting in the Internal Medicine Clerkship

    Science.gov (United States)

    Wofford, James L; Singh, Sonal

    2006-01-01

    INTRODUCTION Whether the clinical vignettes presented at the Society of General Internal Medicine (SGIM) annual meeting could be of educational value to third year students in the Internal Medicine clerkship has not been studied. OBJECTIVE To explore the relevance and learning value of clinical vignettes from the SGIM national meeting in the Internal Medicine clerkship. SETTING Third year Ambulatory Internal Medicine clerkship at one academic medical center (academic year 2005 to 2006). METHODS Students were introduced to the clinical vignette and oriented to the database of clinical vignettes available through the SGIM annual meeting website. Students then reviewed 5 to 10 clinical vignettes using a worksheet, and rated the learning value of each vignette using a 5-point Likert scale (1 = least, 5 = greatest). A single investigator evaluated congruence of the vignette with the Clerkship Directors of Internal Medicine (CDIM)-SGIM curriculum to assess relevance. MAIN RESULTS A total of 42 students evaluated 371 clinical vignettes from the 2004 and 2005 meetings. The clinical vignettes were curriculum-congruent in 42.6% (n = 175), and clearly incongruent in 40.4% (n = 164). The mean rating for learning value was 3.8 (±1.0) (5 signifying greatest learning value). Curriculum-congruent vignettes had a higher mean learning value compared with curriculum-incongruent vignettes (4.0 vs 3.6, Student's t-test, P =.017). CONCLUSION The clinical vignettes presented at the national SGIM meeting offer clinical content that is relevant and of some educational value for third year clerkship students. Based on this pilot study, the educational value and strategies for their use in the clinical clerkships deserve further study. PMID:17026730

  13. Reference values for rotational thromboelastometry (ROTEM) in clinically healthy cats.

    Science.gov (United States)

    Marly-Voquer, Charlotte; Riond, Barbara; Jud Schefer, Rahel; Kutter, Annette P N

    2017-03-01

    To establish reference intervals for rotational thromboelastometry (ROTEM) using feline blood. Prospective study. University teaching hospital. Twenty-three clinically healthy cats between 1 and 15 years. For each cat, whole blood was collected via jugular or medial saphenous venipuncture, and blood was placed into a serum tube, a tube containing potassium-EDTA, and tubes containing 3.2% sodium citrate. The tubes were maintained at 37°C for a maximum of 30 minutes before coagulation testing. ROTEM tests included the EXTEM, INTEM, FIBTEM, and APTEM assays. In addition, prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen concentration (Clauss method) were analyzed for each cat. Reference intervals for ROTEM were calculated using the 2.5-97.5 th percentile for each parameter, and correlation with the standard coagulation profile was performed. Compared to people, clinically healthy cats had similar values for the EXTEM and INTEM assays, but had lower plasma fibrinogen concentrations (0.9-2.2 g/L), resulting in weaker maximum clot firmness (MCF, 3-10 mm) in the FIBTEM test. In 18 cats, maximum lysis (ML) values in the APTEM test were higher than in the EXTEM test, which seems unlikely to have occurred in the presence of aprotinin. It is possible that the observed high maximum lysis values were due to clot retraction rather than true clot lysis. Further studies will be required to test this hypothesis. Cats have a weaker clot in the FIBTEM test, but have a similar clot strength to human blood in the other ROTEM assays, which may be due to a stronger contribution of platelets compared to that found in people. In cats, careful interpretation of the results to diagnose hyperfibrinolysis is advised, especially with the APTEM test, until further data are available. © Veterinary Emergency and Critical Care Society 2017.

  14. Neutron-induced mutation experiments. Progress report, March 1, 1976--February 28, 1977

    International Nuclear Information System (INIS)

    Abrahamson, S.

    1976-11-01

    Results are from studies of experiments in Drosophila on the relative mutagenic effectiveness of neutrons of different energies employing X-linked recessive lethal and specific locus mutation tests. The energies and doses employed to data are .43 MeV (500, 1000, and 1500 R, in progress), .68 MeV (250, 500, 1000, and 1500 R), 2 and 6 MeV (250 and 500 R), and 15 MeV (250, 500, 1000, 1500 and 3000 R). .68 MeV neutrons appear to have an RBE between 3.3 to 4.5, 15 MeV neutrons an RBE between 1.9 to 2.2, and 2 and 6 MeV neutrons RBE's of intermediate values. The data for both .68 and 15 MeV neutrons do not yet differentiate between a linear and quadratic dose/frequency response curve for the doses studied. The specific locus mutation data also indicate the highest RBE for .68 MeV, followed by 2 and 6 MeV respectively

  15. The value of case-based teaching vignettes in clinical microbiology rounds.

    Science.gov (United States)

    Spicer, Jennifer O; Kraft, Colleen S; Burd, Eileen M; Armstrong, Wendy S; Guarner, Jeannette

    2014-03-01

    To describe the implementation and evaluation of a case-based microbiology curriculum during daily microbiology rounds. Vignettes consist of short cases with images and questions that facilitate discussion among microbiologists, pathologists, infectious disease physicians, and trainees (residents and fellows). We performed a survey to assess the value of these vignettes to trainees. Motivation to come to rounds on time increased from 60% to 100%. Trainees attending rounds after implementation of the vignettes perceived the value of microbiology rounds to be significantly higher compared with those who attended rounds before implementation (P = .04). Pathology residents found that vignettes were helpful for retaining knowledge (8.3 of 10 points). The vignettes have enhanced the value of microbiology rounds by serving as a formalized curriculum exposing trainees from multiple specialties to various microbiology topics. Emphasis on interdisciplinary interactions between clinical and laboratory personnel was highlighted with this case-based curriculum.

  16. The clinical value of angiography in diseases of the epigastric organs

    International Nuclear Information System (INIS)

    Mertens, A.W.

    1981-01-01

    76 cases in which in the time between 1969 and 1974 coeliacographies were carried out and the diagnoses are clinically manifested were retrospectively analysed. The angiographic symptoms and the diagnostic results are compared to the literature. Following this, the diagnostic and therapeutic value in liver processes, paucreas processes, stomach tumours, gastrointestinal bleedings, traumas of the epigastric organs, catheter embolisation and stopping of acute, severe gastrointestinal bleedings are discussed. The value of angiography in comparison to laparoscopy, ERCP, sonography, and computerized tomography is discussed. At the end, the indication of angiography in diseases of the epigastric organs is summarized in two tables, distinguishing between absolute, relative, strongly restricted indications and no indication at all. (orig./MG) [de

  17. Targeted alpha therapy of mCRPC. Dosimetry estimate of {sup 213}bismuth-PSMA-617

    Energy Technology Data Exchange (ETDEWEB)

    Kratochwil, Clemens; Afshar-Oromieh, Ali; Rathke, Hendrik; Giesel, Frederik L. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); Schmidt, Karl [ABX-CRO, Dresden (Germany); Bruchertseifer, Frank; Morgenstern, Alfred [European Commission - Joint Research Centre, Directorate for Nuclear Safety and Security, Karlsruhe (Germany); Haberkorn, Uwe [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); German Cancer Research Center (DKFZ), Cooperation Unit Nuclear Medicine, Heidelberg (Germany)

    2018-01-15

    PSMA-617 is a small molecule targeting the prostate-specific membrane antigen (PSMA). In this work, we estimate the radiation dosimetry for this ligand labeled with the alpha-emitter {sup 213}Bi. Three patients with metastatic prostate cancer underwent PET scans 0.1 h, 1 h, 2 h, 3 h, 4 h and 5 h after injection of {sup 68}Ga-PSMA-617. Source organs were kidneys, liver, spleen, salivary glands, bladder, red marrow and representative tumor lesions. The imaging nuclide {sup 68}Ga was extrapolated to the half-life of {sup 213}Bi. The residence times of {sup 213}Bi were forwarded to the instable daughter nuclides. OLINDA was used for dosimetry calculation. Results are discussed in comparison to literature data for {sup 225}Ac-PSMA-617. Assuming a relative biological effectiveness of 5 for alpha radiation, the dosimetry estimate revealed equivalent doses of mean 8.1 Sv{sub RBE5}/GBq for salivary glands, 8.1 Sv{sub RBE5}/GBq for kidneys and 0.52 Sv{sub RBE5}/GBq for red marrow. Liver (1.2 Sv{sub RBE5}/GBq), spleen (1.4 Sv{sub RBE5}/GBq), bladder (0.28 Sv{sub RBE5}/GBq) and other organs (0.26 Sv{sub RBE5}/GBq) were not dose-limiting. The effective dose is 0.56 Sv{sub RBE5}/GBq. Tumor lesions were in the range 3.2-9.0 Sv{sub RBE5}/GBq (median 7.6 Sv{sub RBE5}/GBq). Kidneys would limit the cumulative treatment activity to 3.7 GBq; red marrow might limit the maximum single fraction to 2 GBq. Despite promising results, the therapeutic index was inferior compared to {sup 225}Ac-PSMA-617. Dosimetry of {sup 213}Bi-PSMA-617 is in a range traditionally considered reasonable for clinical application. Nevertheless, compared to {sup 225}Ac-PSMA-617, it suffers from higher perfusion-dependent off-target radiation and a longer biological half-life of PSMA-617 in dose-limiting organs than the physical half-life of {sup 213}Bi, rendering this nuclide as a second choice radiolabel for targeted alpha therapy of prostate cancer. (orig.)

  18. Proton Therapy for Breast Cancer After Mastectomy: Early Outcomes of a Prospective Clinical Trial

    International Nuclear Information System (INIS)

    MacDonald, Shannon M.; Patel, Sagar A.; Hickey, Shea; Specht, Michelle; Isakoff, Steven J.; Gadd, Michele; Smith, Barbara L.; Yeap, Beow Y.; Adams, Judith; DeLaney, Thomas F.; Kooy, Hanne; Lu, Hsiao-Ming; Taghian, Alphonse G.

    2013-01-01

    Purpose: Dosimetric planning studies have described potential benefits for the use of proton radiation therapy (RT) for locally advanced breast cancer. We report acute toxicities and feasibility of proton delivery for 12 women treated with postmastectomy proton radiation with or without reconstruction. Methods and Materials: Twelve patients were enrolled in an institutional review board-approved prospective clinical trial. The patients were assessed for skin toxicity, fatigue, and radiation pneumonitis during treatment and at 4 and 8 weeks after the completion of therapy. All patients consented to have photographs taken for documentation of skin toxicity. Results: Eleven of 12 patients had left-sided breast cancer. One patient was treated for right-sided breast cancer with bilateral implants. Five women had permanent implants at the time of RT, and 7 did not have immediate reconstruction. All patients completed proton RT to a dose of 50.4 Gy (relative biological effectiveness [RBE]) to the chest wall and 45 to 50.4 Gy (RBE) to the regional lymphatics. No photon or electron component was used. The maximum skin toxicity during radiation was grade 2, according to the Common Terminology Criteria for Adverse Events (CTCAE). The maximum CTCAE fatigue was grade 3. There have been no cases of RT pneumonitis to date. Conclusions: Proton RT for postmastectomy RT is feasible and well tolerated. This treatment may be warranted for selected patients with unfavorable cardiac anatomy, immediate reconstruction, or both that otherwise limits optimal RT delivery using standard methods

  19. Proton Therapy for Breast Cancer After Mastectomy: Early Outcomes of a Prospective Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, Shannon M., E-mail: smacdonald@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Patel, Sagar A.; Hickey, Shea [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Specht, Michelle [Department of Surgical Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Isakoff, Steven J. [Division of Hematology and Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Gadd, Michele; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Yeap, Beow Y. [Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Adams, Judith; DeLaney, Thomas F.; Kooy, Hanne; Lu, Hsiao-Ming; Taghian, Alphonse G. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2013-07-01

    Purpose: Dosimetric planning studies have described potential benefits for the use of proton radiation therapy (RT) for locally advanced breast cancer. We report acute toxicities and feasibility of proton delivery for 12 women treated with postmastectomy proton radiation with or without reconstruction. Methods and Materials: Twelve patients were enrolled in an institutional review board-approved prospective clinical trial. The patients were assessed for skin toxicity, fatigue, and radiation pneumonitis during treatment and at 4 and 8 weeks after the completion of therapy. All patients consented to have photographs taken for documentation of skin toxicity. Results: Eleven of 12 patients had left-sided breast cancer. One patient was treated for right-sided breast cancer with bilateral implants. Five women had permanent implants at the time of RT, and 7 did not have immediate reconstruction. All patients completed proton RT to a dose of 50.4 Gy (relative biological effectiveness [RBE]) to the chest wall and 45 to 50.4 Gy (RBE) to the regional lymphatics. No photon or electron component was used. The maximum skin toxicity during radiation was grade 2, according to the Common Terminology Criteria for Adverse Events (CTCAE). The maximum CTCAE fatigue was grade 3. There have been no cases of RT pneumonitis to date. Conclusions: Proton RT for postmastectomy RT is feasible and well tolerated. This treatment may be warranted for selected patients with unfavorable cardiac anatomy, immediate reconstruction, or both that otherwise limits optimal RT delivery using standard methods.

  20. Distinct difference in relative biological effectiveness of 252Cf neutrons for the induction of mitotic crossing over and intragenic reversion of the white-ivory allele in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Hoshi, Masaharu; Ikenaga, Mituo

    1996-01-01

    The relative biological effectiveness (RBE) of 252 Cf neutrons was determined for two different types of somatic mutations, i.e., loss of heterozygosity for wing-hair mutations and reversion of the mutant white-ivory eye-color, in Drosophila melanogaster. Loss of heterozygosity for wing-hair mutations results predominantly from mitotic crossing over induced in wing anlage cells of larvae, while the reverse mutation of eye-color is due to an intragenic structural change in the white locus on the X-chromosome. For a quantitative comparison of RBE values for these events, we have constructed a combined mutation assay system so that induced mutant wing-hair clones as well as revertant eye-color clones can be detected simultaneously in the same individuals. Larvae were irradiated at the age of 80±4 h post-oviposition with 252 Cf neutrons or 137 Cs γ-rays, and male adult flies were examined under the microscope for the presence of the two types of clonal mosaic spots appearing. The induction of wing-hair spots per dose unit was much greater for 252 Cf neutrons than for 137 Cs γ -rays, whereas the frequencies of eye-color reversion were similar for neutrons and γ-rays. The estimated RBE values of neutrons were 8.5 and 1.2 for the induction of mutant wing-hair spots and revertant eye-color spots, respectively. These results indicate that the RBE of neutrons is much greater for mitotic crossing over in comparison to the intragenic white-ivory reversion events. Possible causes for the difference in RBE are discussed

  1. The clinical value of detection of serum TGAb and TPOAb level in autoimmune thyroid diseases

    International Nuclear Information System (INIS)

    Min Xiaoxia; Huang Xingming

    2008-01-01

    To study the clinical value of serum TGAb and TPOAb levels in the diagnosis of patients with autoimmune thyroid diseases (AITD), the serum levels of TGAb and TPOAb in 175 patients with AITD and 64 non-AITD patients and 57 health controls were measured by RIA. The results showed that the serum levels of TGAb and TPOAb in AITD patients with GD and HT were significantly higher than that of control group (P 0.05). The detection of serum TGAb and TPOAb levels may have clinical value in the diagnosis, treatment and prognosis of autoimmune thyroid diseases. (authors)

  2. The clinical value of Huangqi injection in the treatment of leucopenia: a meta-analysis of clinical controlled trials.

    Directory of Open Access Journals (Sweden)

    Changsong Zhang

    Full Text Available BACKGROUND: Huangqi injection is derived from Astragalus membranaceus root. In China, recent reports of Huangqi injection for the treatment of leucopenia have emerged. However, a systematic review of these reports has not been performed. Thus, we conducted a meta-analysis of clinical controlled trials to assess the clinical value of Huangqi injection in the treatment of leucopenia. METHODS: We searched the Chinese Biomedical Literature Database (CBM, Wanfang Database, China National Knowledge Infrastructure (CNKI, Chinese Scientific Journals Full-text Database (VIP, as well as PubMed and EMBASE to collect the data about trials of Huangqi injection for treating leucopenia. A meta-analysis was performed using RevMan 5.2 software. RESULTS: A total of 13 studies involving 841 patients were included in this study. The overall study quality was lower according to the Jadad scale. The meta-analysis showed that experimentally treated patients experienced greater therapeutic efficacy and lower white blood cell counts than control groups treated with Western medicine (P < 0.05. No publication bias was evident, according to Egger's test. CONCLUSIONS: The validity of this meta-analysis was limited by the overall poor quality of the included studies. Huangqi injection may have potential clinical value in the treatment of leucopenia, but confirmation with rigorously well-designed multi-center trials is needed.

  3. Utility of repeat testing of critical values: a Q-probes analysis of 86 clinical laboratories.

    Science.gov (United States)

    Lehman, Christopher M; Howanitz, Peter J; Souers, Rhona; Karcher, Donald S

    2014-06-01

    A common laboratory practice is to repeat critical values before reporting the test results to the clinical care provider. This may be an unnecessary step that delays the reporting of critical test results without adding value to the accuracy of the test result. To determine the proportions of repeated chemistry and hematology critical values that differ significantly from the original value as defined by the participating laboratory, to determine the threshold differences defined by the laboratory as clinically significant, and to determine the additional time required to analyze the repeat test. Participants prospectively reviewed critical test results for 4 laboratory tests: glucose, potassium, white blood cell count, and platelet count. Participants reported the following information: initial and repeated test result; time initial and repeat results were first known to laboratory staff; critical result notification time; if the repeat result was still a critical result; if the repeat result was significantly different from the initial result, as judged by the laboratory professional or policy; significant difference threshold, as defined by the laboratory; the make and model of the instrument used for primary and repeat testing. Routine, repeat analysis of critical values is a common practice. Most laboratories did not formally define a significant difference between repeat results. Repeated results were rarely considered significantly different. Median repeated times were at least 17 to 21 minutes for 10% of laboratories. Twenty percent of laboratories reported at least 1 incident in the last calendar year of delayed result reporting that clinicians indicated had adversely affected patient care. Routine repeat analysis of automated chemistry and hematology critical values is unlikely to be clinically useful and may adversely affect patient care.

  4. Dental Students' Perceived Value of Peer-Mentoring Clinical Leadership Experiences.

    Science.gov (United States)

    Sheridan, Rachel A; Hammaker, Daniel J; de Peralta, Tracy L; Fitzgerald, Mark

    2016-03-01

    This pilot study compared second- and fourth-year dental students' perceived values of newly implemented clinical leadership experiences (CLEs) at one U.S. dental school during the 2012-13 academic year. In the CLEs, fourth-year (D4) students mentored second-year (D2) dental students during faculty-supervised patient treatment. The two cohorts' perceived value of the experiences was measured with questionnaires consisting of five-point Likert scale questions and open text responses. Out of a total of 114 D2 and 109 D4 students, 46 D2 students and 35 D4 students participated (response rates of 40.4% and 32.1%, respectively). While responses from both cohorts showed they highly valued the CLEs, the D2s perceived greater value: 4.07 (0.53) v. 3.51 (0.95), pmentor D2s, that the CLEs had educational benefits, and that the CLEs increased their comfort with peer communication. Theme analysis of open text questions revealed that the respondents perceived the D4s were more accessible than faculty and provided guidance and individual attention; the CLEs increased student comfort; the CLEs reinforced D4 skills, knowledge, and confidence; and the CLEs provided management, leadership, and collaborative work experience. Theme analysis also highlighted student concerns about a lack of program structure. Overall, the majority of both groups valued CLEs in their dental education. Particular advantages they perceived were increased comfort, guidance, and attention. Further program development should address student concerns. These results suggest that similar programs should be considered and/or expanded in other dental schools' curricula.

  5. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints.

    Directory of Open Access Journals (Sweden)

    Eliedonna Cacao

    Full Text Available The biological effects of high charge and energy (HZE particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE's using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE's are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10 are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE's against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed.

  6. The induction of somatic mutations by high-LET radiations using the drosophila assay system

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Takatsuji, Toshihiro

    2004-01-01

    Two types of somatic mutation in Drosophila melanogaster were examined to evaluate the relative biological effectiveness (RBE) of 252 Cf neutrons and heavy ions (carbon ions and neon ions) accelerated with a synchrotron for inducing mutations as a function of linear energy transfer (LET). One is the loss of heterozygosity for wing-hair mutations and the other the reversion of the mutant white-ivory. The measurements were made using a combined mutation assay system; so that induced mutant wing-hair clones as well as revertant eye-color clones could be detected simultaneously in the same fly. Larvae were irradiated at the age of 3 days post-oviposition. The efficiency of 252 Cf neutrons for inducing wing-hair mosaic spots is very high, RBE=8.5, but that for eye-color mosaic spot is almost equal (RBE=1.2) to that of 137 Cs γ-rays. RBE-LET relationships were obtained for the induction of wing-hair and eye-color mosaic spots. The RBE of carbon and neon ions for producing wing-hair mosaic spots increased with increasing LET values. The RBE for the induction of eye-color mutants did not change with LET. These relationships suggest that more complex types of DNA damage such as non-rejoinable strand breaks or clustered double strand breaks that increase with LET may be responsible for inducing the wing-hair mutation, while simpler forms of molecular damage may induce reversion in the white-ivory allele. (author)

  7. Clinical Correlates and Prognostic Value of Proenkephalin in Acute and Chronic Heart Failure

    NARCIS (Netherlands)

    Matsue, Yuya; ter Maaten, Jozine M.; Struck, Joachim; Metra, Marco; O'Connor, Christopher M.; Ponikowski, Piotr; Teerlink, John R.; Cotter, Gad; Davison, Beth; Cleland, John G.; Givertz, Michael M.; Bloomfield, Daniel M.; Dittrich, Howard C.; van Veldhuisen, Dirk J.; van der Meer, Peter; Damman, Kevin; Voors, Adriaan A.

    Background: Proenkephalin (pro-ENK) has emerged as a novel biomarker associated with both renal function and cardiac function. However, its clinical and prognostic value have not been well evaluated in symptomatic patients with heart failure. Methods and Results: The association between pro-ENK and

  8. Prognostic value of fractional flow reserve: linking physiologic severity to clinical outcomes.

    Science.gov (United States)

    Johnson, Nils P; Tóth, Gábor G; Lai, Dejian; Zhu, Hongjian; Açar, Göksel; Agostoni, Pierfrancesco; Appelman, Yolande; Arslan, Fatih; Barbato, Emanuele; Chen, Shao-Liang; Di Serafino, Luigi; Domínguez-Franco, Antonio J; Dupouy, Patrick; Esen, Ali M; Esen, Ozlem B; Hamilos, Michalis; Iwasaki, Kohichiro; Jensen, Lisette O; Jiménez-Navarro, Manuel F; Katritsis, Demosthenes G; Kocaman, Sinan A; Koo, Bon-Kwon; López-Palop, Ramón; Lorin, Jeffrey D; Miller, Louis H; Muller, Olivier; Nam, Chang-Wook; Oud, Niels; Puymirat, Etienne; Rieber, Johannes; Rioufol, Gilles; Rodés-Cabau, Josep; Sedlis, Steven P; Takeishi, Yasuchika; Tonino, Pim A L; Van Belle, Eric; Verna, Edoardo; Werner, Gerald S; Fearon, William F; Pijls, Nico H J; De Bruyne, Bernard; Gould, K Lance

    2014-10-21

    Fractional flow reserve (FFR) has become an established tool for guiding treatment, but its graded relationship to clinical outcomes as modulated by medical therapy versus revascularization remains unclear. The study hypothesized that FFR displays a continuous relationship between its numeric value and prognosis, such that lower FFR values confer a higher risk and therefore receive larger absolute benefits from revascularization. Meta-analysis of study- and patient-level data investigated prognosis after FFR measurement. An interaction term between FFR and revascularization status allowed for an outcomes-based threshold. A total of 9,173 (study-level) and 6,961 (patient-level) lesions were included with a median follow-up of 16 and 14 months, respectively. Clinical events increased as FFR decreased, and revascularization showed larger net benefit for lower baseline FFR values. Outcomes-derived FFR thresholds generally occurred around the range 0.75 to 0.80, although limited due to confounding by indication. FFR measured immediately after stenting also showed an inverse relationship with prognosis (hazard ratio: 0.86, 95% confidence interval: 0.80 to 0.93; p < 0.001). An FFR-assisted strategy led to revascularization roughly half as often as an anatomy-based strategy, but with 20% fewer adverse events and 10% better angina relief. FFR demonstrates a continuous and independent relationship with subsequent outcomes, modulated by medical therapy versus revascularization. Lesions with lower FFR values receive larger absolute benefits from revascularization. Measurement of FFR immediately after stenting also shows an inverse gradient of risk, likely from residual diffuse disease. An FFR-guided revascularization strategy significantly reduces events and increases freedom from angina with fewer procedures than an anatomy-based strategy. Copyright © 2014. Published by Elsevier Inc.

  9. Searching for neurodegeneration in multiple sclerosis at clinical onset: Diagnostic value of biomarkers.

    Science.gov (United States)

    Novakova, Lenka; Axelsson, Markus; Malmeström, Clas; Imberg, Henrik; Elias, Olle; Zetterberg, Henrik; Nerman, Olle; Lycke, Jan

    2018-01-01

    Neurodegeneration occurs during the early stages of multiple sclerosis. It is an essential, devastating part of the pathophysiology. Tools for measuring the degree of neurodegeneration could improve diagnostics and patient characterization. This study aimed to determine the diagnostic value of biomarkers of degeneration in patients with recent clinical onset of suspected multiple sclerosis, and to evaluate these biomarkers for characterizing disease course. This cross-sectional study included 271 patients with clinical features of suspected multiple sclerosis onset and was the baseline of a prospective study. After diagnostic investigations, the patients were classified into the following disease groups: patients with clinically isolated syndrome (n = 4) or early relapsing remitting multiple sclerosis (early RRMS; n = 93); patients with relapsing remitting multiple sclerosis with disease durations ≥2 years (established RRMS; n = 39); patients without multiple sclerosis, but showing symptoms (symptomatic controls; n = 89); and patients diagnosed with other diseases (n = 46). In addition, we included healthy controls (n = 51) and patients with progressive multiple sclerosis (n = 23). We analyzed six biomarkers of neurodegeneration: cerebrospinal fluid neurofilament light chain levels; cerebral spinal fluid glial fibrillary acidic protein; cerebral spinal fluid tau; retinal nerve fiber layer thickness; macula volume; and the brain parenchymal fraction. Except for increased cerebral spinal fluid neurofilament light chain levels, median 670 ng/L (IQR 400-2110), we could not find signs of early degeneration in the early disease group with recent clinical onset. However, the intrathecal immunoglobin G production and cerebral spinal fluid neurofilament light chain levels showed diagnostic value. Moreover, elevated levels of cerebral spinal fluid glial fibrillary acidic protein, thin retinal nerve fiber layers, and low brain parenchymal fractions were associated with

  10. Teratogenic and embryolethal effects in mice of fission-spectrum neutrons and γ-rays

    International Nuclear Information System (INIS)

    Cairnie, A.B.; Grahn, D.; Rayburn, H.B.; Williamson, F.S.; Brown, R.J.

    1974-01-01

    Fission-spectrum neutrons from the Janus reactor at Argonne National Laboratory were compared with γ-rays in terms of their relative biological effectiveness (RBE) for embryolethal and teratogenic effects in mice. No evidence was found of any processes that were abnormally sensitive to neutrons. The RBE for killing embryos and producing abnormal embryos or specific abnormalities was between 2 and 3. This is close to the values found in other systems for processes involving cell killing. (U.S.)

  11. WE-E-BRE-07: High-Throughput Mapping of Proton Biologic Effect

    Energy Technology Data Exchange (ETDEWEB)

    Bronk, L; Guan, F; Kerr, M; Dinh, J; Titt, U; Mirkovic, D; Lin, S; Mohan, R; Grosshans, D [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: To systematically relate the relative biological effectives (RBE) of proton therapy to beam linear energy transfer (LET) and dose. Methods: Using a custom irradiation apparatus previously characterized by our group, H460 NSCLCs were irradiated using a clinical 80MeV spot scanning proton beam. Utilizing this system allowed for high-throughput clonogenic assays performed in 96-well tissue culture plates as opposed to the traditional 6-well technique. Each column in the 96-well plate received a set LET-dose combination. By altering the total number of dose repaintings, numerous dose-LET configurations were examined to effectively generate surviving fraction (SF) data over the entire Bragg peak. The clonogenic assay was performed post-irradiation using an INCell Analyzer for colony quantification. SF data were fit to the linear-quadratic model for analysis. Results: Irradiation with increasing LETs resulted in decreased cell survival largely independent of dose. A significant correlation between LET and SF was identified by two-way ANOVA and the extra sum-of-squares F test. This trend was obscured at the lower LET values in the plateau region of the Bragg peak; however, it was clear for LET values at and beyond the Bragg peak. Data fits revealed the SF at a dose of 2Gy (SF2) to be 0.48 for the lowest tested LET (1.55keV/um), 0.47 at the end of the plateau region (4.74keV/um) and 0.33 for protons at the Bragg peak (10.35keV/um). Beyond the Bragg peak we measured SF2s of 0.16 for 15.01keV/um, 0.02 for 16.79keV/um, and 0.004 for 18.06keV/um. Conclusion: We have shown that our methodology enables high-content automated screening for proton irradiations over a range of LETs. The observed decrease in cellular SF in high LET regions confirms an increased RBE of the radiation and suggests further evaluation of proton RBE values is necessary to optimize clinical outcomes. Rosalie B. Hite Graduate Fellowship in Cancer Research, NIH Program Project Grant P01CA021239.

  12. The Value of Laboratory Tests in Diagnosing Secondary Osteoporosis at a Fracture and Osteoporosis Outpatient Clinic

    NARCIS (Netherlands)

    de Klerk, Gijs; Hegeman, J. Han; van der Velde, Detlef; van der Palen, Jacobus Adrianus Maria; ten Duis, Henk J.

    2013-01-01

    Background: As more and more patients meeting the criteria for osteoporosis are referred to a fracture and osteoporosis outpatient clinic (FO clinic), the laboratory costs to screen for secondary osteoporosis also increases. This study was conducted to determine the value of screening on underlying

  13. Anorectal physiology measurements are of no value in clinical practice. True or false?

    Science.gov (United States)

    Carty, N. J.; Moran, B.; Johnson, C. D.

    1994-01-01

    This article examines whether there is any clinical value in anorectal physiology measurements. The function of the human rectum is poorly understood and the factors which affect function of the anal sphincters are complex. Several laboratories have reported results of anorectal physiology measurements, but there is extensive variation between normal values in different laboratories. It is argued that anorectal physiology measurements fail to meet the criteria of a useful clinical test: 1. It is not widely available to clinicians; 2. It is not possible to establish a reproducible normal range; 3. Abnormal measurements do not correlate with disease entities or explain symptoms; 4. The results are often unhelpful in diagnosis and management; 5. Clinical outcome after intervention does not correlate with alteration in the measurements obtained. On the other hand it can be argued that anorectal physiology measurements do provide information that assists in the management of conditions such as constipation, anismus, Hirschsprung's disease, faecal incontinence and tenesmus. Management based on biofeedback modification of physiological responses requires these techniques as part of the biofeedback system. There is evidence that this may be appropriate in anismus and solitary rectal ulcer syndrome. However, the assessment of these difficult conditions and the interpretation of the results are probably at present best confined to specialist units. PMID:8074392

  14. Predicting Calcium Values for Gastrointestinal Bleeding Patients in Intensive Care Unit Using Clinical Variables and Fuzzy Modeling

    Directory of Open Access Journals (Sweden)

    G Khalili-Zadeh-Mahani

    2016-07-01

    Full Text Available Introduction: Reducing unnecessary laboratory tests is an essential issue in the Intensive Care Unit. One solution for this issue is to predict the value of a laboratory test to specify the necessity of ordering the tests. The aim of this paper was to propose a clinical decision support system for predicting laboratory tests values. Calcium laboratory tests of three categories of patients, including upper and lower gastrointestinal bleeding, and unspecified hemorrhage of gastrointestinal tract, have been selected as the case studies for this research. Method: In this research, the data have been collected from MIMIC-II database. For predicting calcium laboratory values, a Fuzzy Takagi-Sugeno model is used and the input variables of the model are heart rate and previous value of calcium laboratory test. Results: The results showed that the values of calcium laboratory test for the understudy patients were predictable with an acceptable accuracy. In average, the mean absolute errors of the system for the three categories of the patients are 0.27, 0.29, and 0.28, respectively. Conclusion: In this research, using fuzzy modeling and two variables of heart rate and previous calcium laboratory values, a clinical decision support system was proposed for predicting laboratory values of three categories of patients with gastrointestinal bleeding. Using these two clinical values as input variables, the obtained results were acceptable and showed the capability of the proposed system in predicting calcium laboratory values. For achieving better results, the impact of more input variables should be studied. Since, the proposed system predicts the laboratory values instead of just predicting the necessity of the laboratory tests; it was more generalized than previous studies. So, the proposed method let the specialists make the decision depending on the condition of each patient.

  15. The cost and value of pre-registration clinical placements for Project 2000 students.

    Science.gov (United States)

    Jones, M L; Akehurst, R

    1999-07-01

    The research outlined in this article was commissioned by the Sheffield and North Trent College of Nursing and Midwifery to explore the cost implications of pre-registration clinical placements in the context of Project 2000. The authors outline the methodology and findings of an exercise designed to collect relevant cost information which was not readily available. On the basis of these findings, they suggest that: at 1995/1996 pay and prices, clinical placements cost the education provider approximately pound 890 per student per annum; in terms of real resources, the value to service providers of the service contribution made by second- and third-year nursing and midwifery students on ward-based placements outweighs the value of the time spent by qualified staff on their supervision and education. Once the funding assumptions underlying the introduction of Project 2000 have been taken into account, second- and third-year nursing and midwifery students benefit the service provider by on average pound 3.46 for every hour they spend in an unrostered ward-based placement. The service contribution made by students in community-based clinical placements cannot free staff time in the same way as on the wards and, because qualified staff in these areas are generally more highly graded, the value of the time they spend on the supervision and education of students on placement is higher than in ward-based placements. Second- and third-year students therefore appear to cost the service provider on average pound 0.48 for each hour they spend in a community-based placement. It was not possible to determine whether this cost translates into a reduction in patient contacts.

  16. External Beam Radiotherapy for Clinically Localized Hormone-Refractory Prostate Cancer: Clinical Significance of Nadir Prostate-Specific Antigen Value Within 12 Months

    International Nuclear Information System (INIS)

    Ogawa, Kazuhiko; Nakamura, Katsumasa; Sasaki, Tomonari; Onishi, Hiroshi; Koizumi, Masahiko; Shioyama, Yoshiyuki; Araya, Masayuki; Mukumoto, Nobutaka M.S.; Mitsumori, Michihide; Teshima, Teruki

    2009-01-01

    Purpose: To analyze retrospectively the results of external beam radiotherapy for clinically localized hormone-refractory prostate cancer and investigate the clinical significance of nadir prostate-specific antigen (PSA) value within 12 months (nPSA12) as an early estimate of clinical outcomes after radiotherapy. Methods and Materials: Eighty-four patients with localized hormone-refractory prostate cancer treated with external beam radiotherapy were retrospectively reviewed. The total radiation doses ranged from 30 to 76 Gy (median, 66 Gy), and the median follow-up period for all 84 patients was 26.9 months (range, 2.7-77.3 months). Results: The 3-year actuarial overall survival, progression-free survival (PFS), and local control rates in all 84 patients after radiotherapy were 67%, 61%, and 93%, respectively. Although distant metastases and/or regional lymph node metastases developed in 34 patients (40%) after radiotherapy, local progression was observed in only 5 patients (6%). Of all 84 patients, the median nPSA12 in patients with clinical failure and in patients without clinical failure was 3.1 ng/mL and 0.5 ng/mL, respectively. When dividing patients according to low (<0.5 ng/mL) and high (≥0.5 ng/mL) nPSA12 levels, the 3-year PFS rate in patients with low nPSA12 and in those with high nPSA12 was 96% and 44%, respectively (p < 0.0001). In univariate analysis, nPSA12 and pretreatment PSA value had a significant impact on PFS, and in multivariate analysis nPSA12 alone was an independent prognostic factor for PFS after radiotherapy. Conclusions: External beam radiotherapy had an excellent local control rate for clinically localized hormone-refractory prostate cancer, and nPSA12 was predictive of clinical outcomes after radiotherapy.

  17. Clinical reference value of retinal microvascular changes in patients with cerebral microbleeds

    Directory of Open Access Journals (Sweden)

    Ji-Yuan Guo

    2014-12-01

    Full Text Available AIM: To study clinical reference value of retinal microvascular changes in patients with cerebral microbleeds(CMBsand discuss its clinical significance. METHODS:From January 2012 to December 2013, 125 hospitalized patients were collected, including 81 cases were male, 44 cases were female, mean age 76.3±11.2 years old. For all patients, functions of liver and kidney, blood-lipoids, blood sugar and blood biochemical examination were tested, and fundus photography and cerebral MR was done. According to the fundus camera eyes, retinal arteriolar equivalent(RAE, retinal venular equivalent(RVE, retinal vein diameter ratio(AVRand arteriovenous crossing sign(AVNwere identified, CMBs were classified with cerebral MRI. All the data were processed by SPSS statistical software. RESULTS: The central retinal arteriolar equivalent(CRAE, central retinal venular equivalent(CRVEand AVR values in the eyes were found no statistical difference(PPCOCLUSION: The results show that retinal microvascular changes, especially small retinal vein arteriovenous cross width, and arteriovenous crossing phenomenon, in which CMBs will happen more likely. After sex, age, hypertension and hyperglycemia in patients with traditional cardiovascular risk factors being ruled out, the retinal microvascular changes are still relatively factors of CMB's occurrence.

  18. Early Toxicity in Patients Treated With Postoperative Proton Therapy for Locally Advanced Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cuaron, John J. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Chon, Brian; Tsai, Henry; Goenka, Anuj; DeBlois, David [Procure Proton Therapy Center, Somerset, New Jersey (United States); Ho, Alice; Powell, Simon [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Hug, Eugen [Procure Proton Therapy Center, Somerset, New Jersey (United States); Cahlon, Oren, E-mail: cahlono@mskcc.org [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Procure Proton Therapy Center, Somerset, New Jersey (United States)

    2015-06-01

    Purpose: To report dosimetry and early toxicity data in breast cancer patients treated with postoperative proton radiation therapy. Methods and Materials: From March 2013 to April 2014, 30 patients with nonmetastatic breast cancer and no history of prior radiation were treated with proton therapy at a single proton center. Patient characteristics and dosimetry were obtained through chart review. Patients were seen weekly while on treatment, at 1 month after radiation therapy completion, and at 3- to 6-month intervals thereafter. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Frequencies of toxicities were tabulated. Results: Median dose delivered was 50.4 Gy (relative biological equivalent [RBE]) in 5 weeks. Target volumes included the breast/chest wall and regional lymph nodes including the internal mammary lymph nodes (in 93%). No patients required a treatment break. Among patients with >3 months of follow-up (n=28), grade 2 dermatitis occurred in 20 patients (71.4%), with 8 (28.6%) experiencing moist desquamation. Grade 2 esophagitis occurred in 8 patients (28.6%). Grade 3 reconstructive complications occurred in 1 patient. The median planning target volume V95 was 96.43% (range, 79.39%-99.60%). The median mean heart dose was 0.88 Gy (RBE) [range, 0.01-3.20 Gy (RBE)] for all patients, and 1.00 Gy (RBE) among patients with left-sided tumors. The median V20 of the ipsilateral lung was 16.50% (range, 6.1%-30.3%). The median contralateral lung V5 was 0.34% (range, 0%-5.30%). The median maximal point dose to the esophagus was 45.65 Gy (RBE) [range, 0-65.4 Gy (RBE)]. The median contralateral breast mean dose was 0.29 Gy (RBE) [range, 0.03-3.50 Gy (RBE)]. Conclusions: Postoperative proton therapy is well tolerated, with acceptable rates of skin toxicity. Proton therapy favorably spares normal tissue without compromising target coverage. Further follow-up is necessary to assess for clinical outcomes and cardiopulmonary

  19. The relative biological effectiveness of radiations of different quality

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper is a review of the literature relevant to the selection of relative biological effectiveness (RBE) values for use in arriving at values of the quality factor (Q). Emphasis is placed on response to small ( M . In a wide variety of systems, the RBE M for fast (fission) neutrons, with low doses and dose rates, appears to be of the order of 20 or more compared to moderately filtered 250 kVp x rays and 40 or more compared to higher energy gamma rays. These values, which are much larger than those observed with large doses delivered at high dose rates, are due mainly, but not entirely, to a decrease in the slope of the curve for the ow-LET reference radiation at low dose

  20. Compound biological effectiveness (CBE) factors in human undifferentiated thyroid cancer (UTC)

    International Nuclear Information System (INIS)

    Dagrosa, M.A.; Pisarev, M.; Chung, Y.; Coderre, J.; Riley, K.; Binns, P.; Kahl, S.

    2006-01-01

    We determined the CBE values for BPA an BOPP both individually and combined in a human UTC cell line as preliminary data for future treatments with BNCT. In these studies the exponentially growing cell line (ARO) were distributed into the following groups: 1) BPA (10 ppm 10 B) +neutrons; 2) BOPP (10 ppm 10 B) + neutrons; 3) BPA (5 ppm 10 B) + BOPP (5 ppm 10 B) + neutrons; 4) neutrons alone; 5) X-rays. The cells were irradiated in the thermal neutron beam of the MIT Research Reactor (flux=8.5 10 9 n/cm 2 sec). Surviving fraction (SF) was studied as the endpoint from colony forming assays. The RBE of the beam as well as the CBEs for BPA and BOPP both individually and in combination were determined for two different endpoints. At SF of 0.02 and 0.07 respectively the results were beam RBE: 1.2 and 1.2; CBE for BPA: 3.0 and 3.9; CBE for BOPP: 1.6 and 1.7; and the CBE for BPA and BOPP in combination: 2.4 and 2.6. The CBE values for BPA in combination with BOPP appear additive. These are the first measured data for CBEs for UTC that should prove useful for future clinical studies. (author)

  1. The 5 Clinical Pillars of Value for Total Joint Arthroplasty in a Bundled Payment Paradigm.

    Science.gov (United States)

    Kim, Kelvin; Iorio, Richard

    2017-06-01

    Our large, urban, tertiary, university-based institution reflects on its 4-year experience with Bundled Payments for Care Improvement. We will describe the importance of 5 clinical pillars that have contributed to the early success of our bundled payment initiative. We are convinced that value-based care delivered through bundled payment initiatives is the best method to optimize patient outcomes while rewarding surgeons and hospitals for adapting to the evolving healthcare reforms. We summarize a number of experiences and lessons learned since the implementation of Bundled Payments for Care Improvement at our institution. Our experience has led to the development of more refined clinical pathways and coordination of care through evidence-based approaches. We have established that the success of the bundled payment program rests on the following 5 main clinical pillars: (1) optimizing patient selection and comorbidities; (2) optimizing care coordination, patient education, shared decision making, and patient expectations; (3) using a multimodal pain management protocol and minimizing narcotic use to facilitate rapid rehabilitation; (4) optimizing blood management, and standardizing venous thromboembolic disease prophylaxis treatment by risk standardizing patients and minimizing the use of aggressive anticoagulation; and (5) minimizing post-acute facility and resource utilization, and maximizing home resources for patient recovery. From our extensive experience with bundled payment models, we have established 5 clinical pillars of value for bundled payments. Our hope is that these principles will help ease the transition to value-based care for less-experienced healthcare systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Clinical application value of impulse oscillometry in geriatric patients with COPD

    Directory of Open Access Journals (Sweden)

    Liu Z

    2017-03-01

    Full Text Available Zhonghui Liu,* Lianjun Lin,* Xinmin Liu Geriatrics Department, Peking University First Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Background: The diagnosis and assessment of COPD rely mainly on the use of spirometry, which is an effort-dependent test and requires good patient cooperation. Impulse oscillometry (IOS is a non-volitional method that requires less effort and cooperation and presents advantages for geriatric patients. However, the clinical application value of IOS in geriatric patients with COPD remains unclear. Aim: The aim of this study was to investigate the clinical application value of IOS in geriatric patients with COPD. Subjects and methods: A total of 234 subjects were retrospectively enrolled in this study, including 133 patients with COPD and 101 healthy volunteers. All the participants underwent IOS and spirometry examination. The data were collected and analyzed in the overall group, the geriatric group (aged ≥65 years, and the advanced elderly group (aged ≥80 years. Results: 1 In COPD patients, a significant increase in respiratory impedance (Z5, resonant frequency (Fres, and respiratory resistance (R5, R20, R5–R20 and a decrease in respiratory reactance (X5 were observed in the overall group, the geriatric group, and the advanced elderly group compared with the healthy control subjects. 2 The IOS parameters correlated well with spirometry in COPD. In particular, R5–R20 showed the best correlation with forced expiratory volume in 1 second (FEV1 in the different age groups. 3 Fres and R5–R20 had the best diagnostic efficiency for COPD. The area under the curve (AUC values for Fres, expressed by the receiver operating characteristic (ROC curve, were 0.905, 0.909, and 0.914, for the different age groups, respectively. 4 The optimal cutoff values for Fres to diagnose airflow obstruction from ROC curves was 17.715 in the COPD patients. Its sensitivity and

  3. Clinical value of homodynamic numerical simulation applied in the treatment of cerebral aneurysm.

    Science.gov (United States)

    Zhang, Hailin; Li, Li; Cheng, Chongjie; Sun, Xiaochuan

    2017-12-01

    Our objective was to evaluate the clinical value of numerical simulation in diagnosing cerebral aneurysm based on the analysis of numerical simulation of hemodynamic model. The experimental method used was the numerical model of cerebral aneurysm hemodynamic, and the numerical value of blood flow at each point was analyzed. The results showed that, the wall shear stress (WSS) value on the top of CA1 was significantly lower than that of the top (Pvalue of each point on the CA2 tumor was significantly lower than that of tumor neck (Pvalue on the tumor top and tumor neck between CA1 and CA2 had no significant difference (P>0.05); the unsteady index of shear (UIS) value at the points of 20 had distinctly changed, the wave range was 0.6-1.5; the unsteady index of pressure value of every point was significantly lower than UIS value, the wave range was 0.25-0.40. In conclusion, the application of cerebral aneurysm hemodynamic research can help doctors to diagnose cerebral aneurysm more precisely and to grasp the opportunity of treatment during the formulating of the treatment strategies.

  4. Understanding patient values and the manifestations in clinical research with traditional chinese medicine-with practical suggestions for trial design and implementation.

    Science.gov (United States)

    Mu, Wei; Shang, Hongcai

    2013-01-01

    Objective. To define patient values, identify their manifestations in a randomized clinical trial, and investigate the possible implications for clinical research of traditional Chinese medicine. Methods. We categorized patient values manifestations into patient choice, preference, compliance, and patient-reported outcomes and summarized the underlying personal values through purposeful electronic searches for relevant reports. By hypothesizing a set of positive versus negative circumstances occurring in the enrollment, intervention allocation, treatment, and the follow-up stage of a trial, it is possible to discuss the potential implications of patient values manifestation on a trial with traditional Chinese medicine. Results. Patient values and its manifestations are ubiquitous in the process of clinical research with traditional Chinese medicine. These values may provide motivation for participation or engender the internal and external validity of the study. Conclusions. Trialists should attach sufficient importance to the needs and concerns of individual participant. To incorporate patient values into the design and conduct of a clinical study with traditional Chinese medicine, researchers are recommended to adopt participant-friendly design and use patient-reported outcomes, take convenience-for-patients measures, and help foster rational beliefs and behaviors of trial participants.

  5. Understanding Patient Values and the Manifestations in Clinical Research with Traditional Chinese Medicine—With Practical Suggestions for Trial Design and Implementation

    Directory of Open Access Journals (Sweden)

    Wei Mu

    2013-01-01

    Full Text Available Objective. To define patient values, identify their manifestations in a randomized clinical trial, and investigate the possible implications for clinical research of traditional Chinese medicine. Methods. We categorized patient values manifestations into patient choice, preference, compliance, and patient-reported outcomes and summarized the underlying personal values through purposeful electronic searches for relevant reports. By hypothesizing a set of positive versus negative circumstances occurring in the enrollment, intervention allocation, treatment, and the follow-up stage of a trial, it is possible to discuss the potential implications of patient values manifestation on a trial with traditional Chinese medicine. Results. Patient values and its manifestations are ubiquitous in the process of clinical research with traditional Chinese medicine. These values may provide motivation for participation or engender the internal and external validity of the study. Conclusions. Trialists should attach sufficient importance to the needs and concerns of individual participant. To incorporate patient values into the design and conduct of a clinical study with traditional Chinese medicine, researchers are recommended to adopt participant-friendly design and use patient-reported outcomes, take convenience-for-patients measures, and help foster rational beliefs and behaviors of trial participants.

  6. Echocardiography and risk prediction in advanced heart failure: incremental value over clinical markers.

    Science.gov (United States)

    Agha, Syed A; Kalogeropoulos, Andreas P; Shih, Jeffrey; Georgiopoulou, Vasiliki V; Giamouzis, Grigorios; Anarado, Perry; Mangalat, Deepa; Hussain, Imad; Book, Wendy; Laskar, Sonjoy; Smith, Andrew L; Martin, Randolph; Butler, Javed

    2009-09-01

    Incremental value of echocardiography over clinical parameters for outcome prediction in advanced heart failure (HF) is not well established. We evaluated 223 patients with advanced HF receiving optimal therapy (91.9% angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 92.8% beta-blockers, 71.8% biventricular pacemaker, and/or defibrillator use). The Seattle Heart Failure Model (SHFM) was used as the reference clinical risk prediction scheme. The incremental value of echocardiographic parameters for event prediction (death or urgent heart transplantation) was measured by the improvement in fit and discrimination achieved by addition of standard echocardiographic parameters to the SHFM. After a median follow-up of 2.4 years, there were 38 (17.0%) events (35 deaths; 3 urgent transplants). The SHFM had likelihood ratio (LR) chi(2) 32.0 and C statistic 0.756 for event prediction. Left ventricular end-systolic volume, stroke volume, and severe tricuspid regurgitation were independent echocardiographic predictors of events. The addition of these parameters to SHFM improved LR chi(2) to 72.0 and C statistic to 0.866 (P advanced HF.

  7. The relative biological effectiveness of a high energy neutron beam for micronuclei induction in T-lymphocytes of different individuals

    Energy Technology Data Exchange (ETDEWEB)

    Slabbert, J.P., E-mail: jps@tlabs.ac.z [NRF iThemba LABS (Laboratory for Accelerated Based Sciences), Somerset West (South Africa); Dept. of Medical Imaging and Clinical Oncology, University of Stellenbosch (South Africa); August, L. [NRF iThemba LABS (Laboratory for Accelerated Based Sciences), Somerset West (South Africa); Vral, A. [Dept. of Basic Medical Sciences, Ghent University (Belgium); Symons, J. [NRF iThemba LABS (Laboratory for Accelerated Based Sciences), Somerset West (South Africa)

    2010-12-15

    In assessing the radiation risk of personnel exposed to cosmic radiation fields as it pertains to radiological damage during travel in civilian aircrafts, it is particularly important to know the relative biological effectiveness (RBE) for high energy neutrons. It has been the subject of numerous investigations in recent years using different neutron energies and cytogenetic examinations. Variations in the radiosensitivity of white blood cells for different individuals are likely to influence the estimate of the relative biological effectiveness for high energy neutrons. This as such observations have been noted in the response of different cancer cell lines with varying inherent sensitivities. In this work the radiosensitivities of T-lymphocytes of different individuals to the p(66)/Be neutron beam at iThemba LABS were measured using micronuclei formations and compared to that noted following exposure to {sup 60}Co {gamma}-rays. The principle objective of this investigation was to establish if a relationship between neutron RBE and variation in biological response to {sup 60}Co {gamma}-rays for lymphocytes from different individuals could be determined. Peripheral blood samples were collected from four healthy donors and isolated lymphocytes were exposed to different doses of {sup 60}Co {gamma}-rays (1-5 Gy) and p(66)/Be neutrons (0.5-2.5 Gy). One sample per donor was not exposed to radiation and served as a control. Lymphocytes were stimulated using PHA and cultured to induce micronuclei in cytokinesis-blocked cells. Micronuclei yields were numerated using fluorescent microscopy. Radiosensitivities and RBE values were calculated from the fitted parameters describing the micronuclei frequency dose response data. Dissimilar dose response curves for different donors were observed reflecting varying inherent sensitivities to both neutron and gamma radiation. A clear reduction in the dose limiting RBE{sub M} is noted for donors with lymphocytes more sensitive to

  8. Clinical value of CD133 and nestin in patients with glioma

    DEFF Research Database (Denmark)

    Dahlrot, Rikke H; Hansen, Steinbjørn; Jensen, Stine S

    2014-01-01

    Cancer stem cell-related (CSC) markers have been suggested to have promising potentials as novel types of prognostic and predictive markers in gliomas. However no single CSC-related marker is currently used in clinical decisions. The aim of this study was to investigate the prognostic value of CD......133 and nestin separately and in combination using a novel quantitative approach in a well-characterized population-based cohort of glioma patients. The expression of CD133 and nestin was measured by systematic random sampling in stained paraffin sections from 239 glioma patients diagnosed between...

  9. Clinical value of positron emission tomography (PET) in oncology: Results of an interdisciplinary consensus conference

    International Nuclear Information System (INIS)

    Reske, S.N.; Bares, R.; Buell, U.; Guhlmann, A.; Moser, E.; Wannenmacher, M.F.

    1996-01-01

    Clinical value of PET in oncology was evaluated by a panel of recognized experts in the framework of an interdisciplinary consensus conference. On the basis of PET studies, well documented in the international literature, the value of PET for solving clinical questions was classified according to the following categories 'appropriate' (1a), 'mostly acceptable' (1b), 'helpful' (2a), 'value as yet unknown' (2b), 'useless' (3). 2-fluorodeoxyglucose (FDG) acts as the radiopharmaceutical of choice for PET in clinical oncology. PET is indicated (1a) for diagnosing relapse in high grade glioma (FDG) or low grade glioma (C-11 methionine or F-18 fluorotyrosine), differential diagnosis of solitary peripheral pulponary nodules in high risk patients and for diagnosis of pancreatic carcinoma. PET may be clinically used (1b): In 'low-grade' glioma, search for unknown primary in head and neck tumors, suspicion of relapse in nonsmall cell bronchial carcinoma (NSCBC) and colorectal carcinoma, lymphnode staging in NSCBC, pancreatic carcinoma, muscle invasive bladder carcinoma and testicular cancer. Staging of Hodgkin's disease (HD, stage I/II vs III), early therapy control in patients with a residual mass or suspicion of relapse in HD and in high grade NHL, lymph node staging and search for distant metastases in malignant melanoma (Breslow>1,5 mm), search for lymph node or distant metastases in differentiated thyroid cancer with elevated hTG and a negative radioiodide whole body scan. Many further indications are emerging, but are not yet sufficiently well documented in the literature. For most indications beside scientific studies, an individual cost benefit utility evaluation by the responsible physician is recommended. (orig./MG) [de

  10. Clinical value of CT in neuropediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Reisner, Th. (Vienna Univ. (Austria). Neurologische Klinik)

    1981-11-27

    Cranial computed-tomography (CT) has opened new dimensions in neuropediatric diagnosis. The relationship between clinical symptoms and CT results is presented. 1930 patients were investigated, one group is made up of 334 newborns and infants, the other group contains children in the age between 13 months and 15 years. Newborns and infants confront the neurologist with stereotyped deficiency symptoms which nevertheless can arise from many causes. CT can make an etiological classification. In childhood illnesses of neurophyschiatric nature sometimes predominate whose clinical symptoms are often minimal (e.g. cerebral seizures, hydrocephalus, perinatal brain damage, various types of headache etc.). Here again CT can give the clinical valuable indications concerning diagnosis and therapeutic procedure.

  11. [A study of work values, professional commitment, turnover intention and related factors among clinical nurses].

    Science.gov (United States)

    Wang, Kuei-Ying; Chou, Chuan-Chiang; Huang, Jui-Lan

    2010-02-01

    The high rate of turnover in nursing positions is a global problem. There have been few studies done addressing the relationship between work values and nurse turnover intention. The purpose of this study was to explore the relationship between work values, professional commitment and turnover intention among clinical nurses. A cross-sectional survey was conducted between February 1st to March 10th, 2008 on a convenience sample of nurses, all of whom had at least a half year of work experience at one of four teaching hospitals in Taiwan. A total of 289 valid responses were received, with a response rate of 96.3%. Major findings included: (1) Nurses who were older, had more years of school, had worked more years, held specific job duties, earned a higher salary, held Buddhist beliefs, or were married with two or more children presented higher work values and professional commitment and lower turnover intention; (2) As a group, total work values and professional commitment scores corresponded negatively with turnover intention scores; (3) Significant factors affecting turnover intent in clinical nurses included professional commitment, institution characteristics, Buddhist beliefs and salary. These four variables accounted for 52.2% of the variation in turnover intention. This study indicated that nurses with higher work values and professional commitment tend to exhibit less turnover intention. It is highly recommended to develop strategies to bolster the teaching of altruistic values and professional commitment in nursing education in order to reduce turnover intent. Also, further studies on the influence of religious beliefs and organizational attributes on nurse turnover intentions are also suggested.

  12. The value of clinical tests in acute full-thickness tears of the supraspinatus tendon

    DEFF Research Database (Denmark)

    Bak, Klaus; Sørensen, Anne Kathrine Belling; Jørgensen, Uffe Viegh

    2010-01-01

    Early repair of rotator cuff tears leads to superior results. To detect symptomatic full-thickness tears of the supraspinatus tendon at an early stage, we conducted a prospective study to evaluate the value of clinical examination with and without subacromial lidocaine within the first weeks after...

  13. [The relevance of ADC value, T₁intensive rate and the clinical activities in ankylosing spondylitis sacroiliitis].

    Science.gov (United States)

    Zhao, Yinghua; Han, Xinai; Hu, Shaoyong; Shi, Xingliang; Zhao, Jing; Sun, Erwei; Li, Shaolin

    2014-09-23

    To evaluate the value of judging for the activity in AS by diffusion-weighted sequences (DWI) and enhance sequences MRI(DCE-MRI), to explore the correlation of Apparent diffusion coefficient(ADC) values, intensive rate and the clinical activity index in sacroiliitis (SIJ) of ankylosing spondylitis (AS). 56 patients prospectively choiced and diagnosed were divided into two groupsas, active group (n = 32) and chronic group (n = 24) by rheumatologist according to BASDAI and laboratory parameters. Twenty healthy adults were as control group. The values of ADC and intensive rate of all sacroiliac joints (SIJs) were measured on MRI. BASDAI score were got by Bath ankylosing spondylitis disease activity index. ESR, CPR and were got by laboratory. Statisticaly to analysis whether the parameters were significantly different amang AS active, chronic, and the control group. To assess the correlation of the values of ADC, intensive rate and BASDAI score, ESR, CPR and in SIJ. the values of ADC and intensive rate were significantly different among AS active, chronic and the control group. There were the significant correlation between the values of ADC, intensive rate and BASDAI score. Diffusion-weighted sequences and Contrast-enhanced sequences is superior to other methods in judging the activity in AS.combined with clinical activity index, the accuracy can significantly be improved to explore whether the activities of AS are.

  14. The relative biological effectiveness of fractionated doses of fast neutrons (42 MeVd→Be) for normal tissues. Pt. 3

    International Nuclear Information System (INIS)

    Rezvani, M.; Hopewell, J.W.; Robbins, M.E.C.; Hamlet, R.; Barnes, D.W.H.; Sansom, J.M.; Adams, P.J.V.

    1990-01-01

    The effect of single and fractionated doses of fast neutrons (42 MeV d→Bc ) on the early and late radiation responses of the pig lung have been assessed by the measurement of changes in lung function using a 133 Xe washout technique. The results obtained for irradiation schedules with fast neutrons have been compared with those after photon irradiation. There was no statistically significant difference between the values for the relative biological effectiveness (RBE) for the early and late radiation response of the lung. The RBE of the neutron beam increased with decreasing size of dose/fraction with an upper limit value of 4.39 ± 0.94 for infinitely small X-ray doses per fraction. (author)

  15. Induction of micronuclei by irradiation with neutrons produced from 600 MeV protons

    CERN Document Server

    Diehl-Marshall, I

    1980-01-01

    Chromosome damage can be detected by the observation of micronuclei . Because its sensitivity, the micronuclei induciton in meristems of Vicia faba bean roots has been selected to determine the radiation damage produced by doses ranging from 1 to 82 cGy of neutrons. The average number of miconuclei found between 24 and 48 hours after irradiation was plotted as a funciton of dose. The RBE values, using as reference radiation 60 Co y-rays, ranged from 3.5 for a neutron dose of 82 cGy to 18 for a neutron of 1 cGy. Even higher RBE values were deduced at low doses from the evaluation of cells containing multiple micronuclei.

  16. Value of the free light chain analysis in the clinical evaluation of response in multiple myeloma patients receiving anti-myeloma therapy

    DEFF Research Database (Denmark)

    Toftmann Hansen, Charlotte; Pedersen, Per T.; Jensen, Bo Amdi

    Value of the free light chain analysis in the clinical evaluation of response in multiple myeloma patients receiving anti-myeloma therapy.......Value of the free light chain analysis in the clinical evaluation of response in multiple myeloma patients receiving anti-myeloma therapy....

  17. 4D co-registration of X-ray and MR-mammograms: initial clinical results and potential incremental diagnostic value.

    Science.gov (United States)

    Dietzel, Matthias; Hopp, Torsten; Ruiter, Nicole V; Kaiser, Clemens G; Kaiser, Werner A; Baltzer, Pascal A

    2015-01-01

    4D co-registration of X-ray- and MR-mammograms (XM and MM) is a new method of image fusion. The present study aims to evaluate its clinical feasibility, radiological accuracy, and potential clinical value. XM and MM of 25 patients were co-registered. Results were evaluated by a blinded reader. Precision of the 4D co-registration was "very good" (mean-score [ms]=7), and lesions were "easier to delineate" (ms=5). In 88.8%, "relevant additional diagnostic information" was present, accounting for a more "confident diagnosis" in 76% (ms=5). 4D co-registration is feasible, accurate, and of potential clinical value. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Biophysical calculations of cell killing probability by the amorphous track structure model for heavy-ion beams

    International Nuclear Information System (INIS)

    Kase, Yuki; Matsufuji, Naruhiro; Furusawa, Yoshiya; Kanai, Tatsuaki

    2007-01-01

    In a treatment planning of heavy-ion radiotherapy, it is necessary to estimate the biological effect of the heavy-ion beams. Physical dose should be associated with the relative biological effectiveness (RBE) at each point. Presently, carbon ion radiotherapy has been carried out at the National Institute Radiological Sciences (NIRS) in Japan and the Gesellschaft fuer Schwerionenforschung mbH (GSI) in Germany. Both facilities take individual approach for the calculation of the RBE value. At NIRS, the classical LQ model has been used while the local effect model (LEM) has been incorporated into the treatment planning system at GSI. The first aim of this study is to explain the RBE model of NIRS by the microdosimetric kinetic model (MKM). In addition, the clarification of similarities and differences between the MKM and the LEM was also investigated. (author)

  19. Clinical value of endoluminal ultrasonography in the diagnosis of rectovaginal fistula

    International Nuclear Information System (INIS)

    Yin, Hao-Qiang; Wang, Chen; Peng, Xin; Xu, Fang; Ren, Ya-Juan; Chao, Yong-Qing; Lu, Jin-Gen; Wang, Song; Xiao, Hu-Sheng

    2016-01-01

    Rectovaginal fistula (RVF) refers to a pathological passage between the rectum and vagina, which is a public health challenge. This study was aimed to explore the clinical value of endoluminal biplane ultrasonography in the diagnosis of rectovaginal fistula (RVF). Thirty inpatients and outpatients with suspected RVF from January 2006 to June 2013 were included in the study, among whom 28 underwent surgical repair. All 28 patients underwent preoperative endoluminal ultrasonography, and the obtained diagnostic results were compared with the corresponding surgical results. All of the internal openings located at the anal canal and rectum of the 28 patients and confirmed during surgery were revealed by preoperative endosonography, which showed a positive predictive value of 100 %. Regarding the 30 internal openings located in the vagina during surgery, the positive predictive value of preoperative endosonography was 93 %. The six cases of simple fistulas confirmed during surgery were revealed by endosonography; for the 22 cases of complex fistula confirmed during surgery, the positive predictive value of endosonography was 90 %. Surgery confirmed 14 cases of anal fistula and 14 cases of RVF, whereas preoperative endoluminal ultrasonography suggested 16 cases of anal fistula and 12 cases of RVF, resulting in positive predictive values of 92.3 and 93 %, respectively. The use of endoluminal biplane ultrasonography in the diagnosis of RVF can accurately determine the internal openings in the rectum or vagina and can relatively accurately identify concomitant branches and abscesses located in the rectovaginal septum. Thus, it is a good imaging tool for examining internal and external anal sphincter injuries and provides useful information for preoperative preparation and postoperative evaluation

  20. Site Specific Microbeam Irradiation: Defining a Bystander Effect. Final Technical Report

    International Nuclear Information System (INIS)

    Brenner, David J.

    2003-01-01

    There is evidence that low-energy x-rays as used in mammography have an increased biological effectiveness relative to higher-energy photons. However, the RBE values are not large, probably less than 2. Thus it is unlikely that the radiation risk alone could prove to be a ''show stopper'' regarding screening mammography because, for older women, the benefit is likely to considerably outweigh the radiation risk. Nevertheless, the RBE for low-energy x-rays might reasonably be taken into account when assessing the recommended age to commence such annual screening

  1. Clinical Laboratory Values as Early Indicators of Ebola Virus Infection in Nonhuman Primates.

    Science.gov (United States)

    Reisler, Ronald B; Yu, Chenggang; Donofrio, Michael J; Warren, Travis K; Wells, Jay B; Stuthman, Kelly S; Garza, Nicole L; Vantongeren, Sean A; Donnelly, Ginger C; Kane, Christopher D; Kortepeter, Mark G; Bavari, Sina; Cardile, Anthony P

    2017-08-01

    The Ebola virus (EBOV) outbreak in West Africa during 2013-2016 demonstrated the need to improve Ebola virus disease (EVD) diagnostics and standards of care. This retrospective study compared laboratory values and clinical features of 3 nonhuman primate models of lethal EVD to assess associations with improved survival time. In addition, the study identified laboratory values useful as predictors of survival, surrogates for EBOV viral loads, and triggers for initiation of therapeutic interventions in these nonhuman primate models. Furthermore, the data support that, in nonhuman primates, the Makona strain of EBOV may be less virulent than the Kikwit strain of EBOV. The applicability of these findings as potential diagnostic and management tools for EVD in humans warrants further investigation.

  2. Small bowel toxicity after high dose spot scanning-based proton beam therapy for paraspinal/retroperitoneal neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, R.A.; Albertini, F.; Koch, T.; Ares, C.; Lomax, A.; Goitein, G. [Paul Scherrer Institute PSI, Villigen (Switzerland). Center for Proton Therapy; Vitolo, V. [Fondazione CNAO, Pavia (Italy); Hug, E.B. [Paul Scherrer Institute PSI, Villigen (Switzerland). Center for Proton Therapy; ProCure Proton Therapy Centers, New York, NY (United States)

    2013-12-15

    Purpose: Mesenchymal tumours require high-dose radiation therapy (RT). Small bowel (SB) dose constraints have historically limited dose delivery to paraspinal and retroperitoneal targets. This retrospective study correlated SB dose-volume histograms with side-effects after proton radiation therapy (PT). Patients and methods: Between 1997 and 2008, 31 patients (mean age 52.1 years) underwent spot scanning-based PT for paraspinal/retroperitoneal chordomas (81 %), sarcomas (16 %) and meningiom (3 %). Mean total prescribed dose was 72.3 Gy (relative biologic effectiveness, RBE) delivered in 1.8-2 Gy (RBE) fractions. Mean follow-up was 3.8 years. Based on the pretreatment planning CT, SB dose distributions were reanalysed. Results: Planning target volume (PTV) was defined as gross tumour volume (GTV) plus 5-7 mm margins. Mean PTV was 560.22 cm{sup 3}. A mean of 93.2 % of the PTV was covered by at least 90 % of the prescribed dose. SB volumes (cm{sup 3}) receiving doses of 5, 20, 30, 40, 50, 60, 70, 75 and 80 Gy (RBE) were calculated to give V5, V20, V30, V40, V50, V60, V70, V75 and V80 respectively. In 7/31 patients, PT was accomplished without any significant SB irradiation (V5 = 0). In 24/31 patients, mean maximum dose (Dmax) to SB was 64.1 Gy (RBE). Despite target doses of > 70 Gy (RBE), SB received > 50 and > 60 Gy (RBE) in only 61 and 54 % of patients, respectively. Mean SB volumes (cm{sup 3}) covered by different dose levels (Gy, RBE) were: V20 (n = 24): 45.1, V50 (n = 19): 17.7, V60 (n = 17): 7.6 and V70 (n = 12): 2.4. No acute toxicity {>=} grade 2 or late SB sequelae were observed. Conclusion: Small noncircumferential volumes of SB tolerated doses in excess of 60 Gy (RBE) without any clinically-significant late adverse effects. This small retrospective study has limited statistical power but encourages further efforts with higher patient numbers to define and establish high-dose threshold models for SB toxicity in modern radiation oncology. (orig.)

  3. Advancing medicine one research note at a time: the educational value in clinical case reports.

    Science.gov (United States)

    Cabán-Martinez, Alberto J; Beltrán, Wilfredo F García

    2012-07-06

    A case report--a brief written note that describes unique aspects of a clinical case--provides a significant function in medicine given its rapid, succinct, and educational contributions to scientific literature and clinical practice. Despite the growth of, and emphasis on, randomized clinical trials and evidenced-based medicine, case reports continue to provide novel and exceptional knowledge in medical education. The journal BMC Research Notes introduces a new "case reports" section to provide the busy clinician with a forum in which to document any authentic clinical case that provide educational value to current clinical practice. The aim is for this article type to be reviewed, wherever possible, by specialized Associate Editors for the journal, in order to provide rapid but thorough decision making. New ideas often garnered by and documented in case reports will support the advancement of medical science--one research note at a time.

  4. Cytotoxicity of 125I decay in the DNA double strand break repair deficient mutant cell line, xrs-5

    International Nuclear Information System (INIS)

    Yasui, L.S.

    1992-01-01

    Survival of parental Chinese hamster ovary (CHO) K1 cells and the DNA double strand break (DSB) repair deficient mutant, xrs-5 was determined after accumulation of 125 I decays. Both CHO and xrs-5 cells were extremely sensitive to accumulated 125 I decays. D o values for CHO and xrs-5 cells were 40 and approximately 7 decays per cell, respectively. Difference in cell survival between CHO and xrs-5 cells was not due to differences in overall 125 IUdR incorporation, differences in labelling index (LI) or differences in plating efficiency (PE). Relative biological effectiveness (RBE) values calculated relative to 137 Cs gamma radiation survival values (D o and D 10 ) were higher in xrs-5 cells compared with CHO cells, although both CHO and xrs-5 cells have high RBE values that correspond to a high sensitivity of CHO and xrs-5 cells to 125 I decay. (Author)

  5. Lung Cancer Cell Line Screen Links Fanconi Anemia/BRCA Pathway Defects to Increased Relative Biological Effectiveness of Proton Radiation

    International Nuclear Information System (INIS)

    Liu, Qi; Ghosh, Priyanjali; Magpayo, Nicole; Testa, Mauro; Tang, Shikui; Gheorghiu, Liliana; Biggs, Peter; Paganetti, Harald; Efstathiou, Jason A.; Lu, Hsiao-Ming; Held, Kathryn D.; Willers, Henning

    2015-01-01

    Purpose: Growing knowledge of genomic heterogeneity in cancer, especially when it results in altered DNA damage responses, requires re-examination of the generic relative biological effectiveness (RBE) of 1.1 of protons. Methods and Materials: For determination of cellular radiosensitivity, we irradiated 17 lung cancer cell lines at the mid-spread-out Bragg peak of a clinical proton beam (linear energy transfer, 2.5 keV/μm). For comparison, 250-kVp X rays and 137 Cs γ-rays were used. To estimate the RBE of protons relative to 60 Co (Co60eq), we assigned an RBE(Co60Eq) of 1.1 to X rays to correct the physical dose measured. Standard DNA repair foci assays were used to monitor damage responses. FANCD2 was depleted using RNA interference. Results: Five lung cancer cell lines (29.4%) exhibited reduced clonogenic survival after proton irradiation compared with X-irradiation with the same physical doses. This was confirmed in a 3-dimensional sphere assay. Corresponding proton RBE(Co60Eq) estimates were statistically significantly different from 1.1 (P≤.05): 1.31 to 1.77 (for a survival fraction of 0.5). In 3 of these lines, increased RBE was correlated with alterations in the Fanconi anemia (FA)/BRCA pathway of DNA repair. In Calu-6 cells, the data pointed toward an FA pathway defect, leading to a previously unreported persistence of proton-induced RAD51 foci. The FA/BRCA-defective cells displayed a 25% increase in the size of subnuclear 53BP1 foci 18 hours after proton irradiation. Conclusions: Our cell line screen has revealed variations in proton RBE that are partly due to FA/BRCA pathway defects, suggesting that the use of a generic RBE for cancers should be revisited. We propose that functional biomarkers, such as size of residual 53BP1 foci, may be used to identify cancers with increased sensitivity to proton radiation

  6. Lung Cancer Cell Line Screen Links Fanconi Anemia/BRCA Pathway Defects to Increased Relative Biological Effectiveness of Proton Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi; Ghosh, Priyanjali; Magpayo, Nicole [Laboratory of Cellular and Molecular Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Testa, Mauro; Tang, Shikui [Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Gheorghiu, Liliana [Laboratory of Cellular and Molecular Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Biggs, Peter; Paganetti, Harald [Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Efstathiou, Jason A. [Laboratory of Cellular and Molecular Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Lu, Hsiao-Ming [Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Held, Kathryn D. [Laboratory of Cellular and Molecular Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Willers, Henning, E-mail: hwillers@mgh.harvard.edu [Laboratory of Cellular and Molecular Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2015-04-01

    Purpose: Growing knowledge of genomic heterogeneity in cancer, especially when it results in altered DNA damage responses, requires re-examination of the generic relative biological effectiveness (RBE) of 1.1 of protons. Methods and Materials: For determination of cellular radiosensitivity, we irradiated 17 lung cancer cell lines at the mid-spread-out Bragg peak of a clinical proton beam (linear energy transfer, 2.5 keV/μm). For comparison, 250-kVp X rays and {sup 137}Cs γ-rays were used. To estimate the RBE of protons relative to {sup 60}Co (Co60eq), we assigned an RBE(Co60Eq) of 1.1 to X rays to correct the physical dose measured. Standard DNA repair foci assays were used to monitor damage responses. FANCD2 was depleted using RNA interference. Results: Five lung cancer cell lines (29.4%) exhibited reduced clonogenic survival after proton irradiation compared with X-irradiation with the same physical doses. This was confirmed in a 3-dimensional sphere assay. Corresponding proton RBE(Co60Eq) estimates were statistically significantly different from 1.1 (P≤.05): 1.31 to 1.77 (for a survival fraction of 0.5). In 3 of these lines, increased RBE was correlated with alterations in the Fanconi anemia (FA)/BRCA pathway of DNA repair. In Calu-6 cells, the data pointed toward an FA pathway defect, leading to a previously unreported persistence of proton-induced RAD51 foci. The FA/BRCA-defective cells displayed a 25% increase in the size of subnuclear 53BP1 foci 18 hours after proton irradiation. Conclusions: Our cell line screen has revealed variations in proton RBE that are partly due to FA/BRCA pathway defects, suggesting that the use of a generic RBE for cancers should be revisited. We propose that functional biomarkers, such as size of residual 53BP1 foci, may be used to identify cancers with increased sensitivity to proton radiation.

  7. Early pleural fluid dynamics following video-assisted thoracoscopic lobectomy has limited clinical value

    DEFF Research Database (Denmark)

    Holbek, Bo Laksáfoss; Petersen, René Horsleben; Kehlet, Henrik

    2017-01-01

    The objective of this study was to evaluate the potential of predicting the pleural fluid output in patients after video-assisted thoracoscopic lobectomy of the lung. Detailed measurements of continuous fluid output were obtained prospectively using an electronic thoracic drainage device (Thopaz...... and 48 hours. Assessment of initial fluid production may predict high 24-hour fluid output (≥500 mL) but seems to lack clinical value in drain removal criteria....

  8. Three-Year Analysis of Value and Utilization After Development of an Ultrasound-Based Orthopedic Injection Clinic.

    Science.gov (United States)

    Dukes, Chase; Melton, Thomas; Turner, Eric; Jackson, Andrew; Grassbaugh, Jason; Slevin, John; Arrington, Edward D; Eichinger, Josef K

    2017-09-01

    Sonography is an effective method of diagnosing and treating musculoskeletal conditions, and the use of ultrasound has been shown to improve the accuracy, safety, and efficacy of both therapeutic and diagnostic injections. In 2012, we established an injection clinic at our institution to address our growing need for diagnostic and therapeutic injections. We performed an analysis of value and utilization following the development of an orthopedic injection clinic. This included an evaluation of the cost of materials, equipment, and training required to develop and run the clinic, and an analysis of the services rendered and relative value units (RVUs) generated over 3 fiscal years (FYs). The cost to develop the clinic was $42,498.30. The cost to run the clinic thereafter was $16.90 to $21.60 per injection. By the end of FY 2012, 60% of providers performed at least 1 injection under ultrasound guidance. Every successive year thereafter, 100% of providers were using ultrasound guidance. In FY 2012, we performed 738 injections, 5.4% used ultrasound guidance and generated a total of 1,786.36 RVUs. In FY 2013, we performed 1,814 injections, 17.6% used ultrasound guidance, and generated a total of 7,224.5 RVUs. In FY 2014, we performed 2,821 injections, 25.2% used ultrasound guidance, and generated 13,786.82 RVUs. RVUs generated solely from ultrasound guided injections were 463.2 (2012), 3,694 (2013), 8,221.8 (2014). Injection accuracy was at least 98%. Average time until injection was 0 days. The cost to start an injection clinic is modest, with the potential for large annual growth and early return on investment, and can generate significant revenue by recapturing RVUs that would otherwise be lost to outside referrals. Furthermore, it helps to increase clinic throughput, maximize services rendered during a single patient visit improving the overall quality of their encounter, expands the clinical practice of our midlevel providers, offloads clinical time for surgical

  9. Microscopical investigation of cellular effects of 135 MeV/amu carbon along the path of the beam

    International Nuclear Information System (INIS)

    Furuse, Masako; Soga, Fuminori; Matsumoto, Shinji

    1993-01-01

    The difference in biological effects are normally described by the concept of RBE. However, the RBE values depend on the LET along a trajectory and also on complicated parameters such as the distribution of the energy deposition due to the difference in the spread of secondary electrons perpendicular to a beam axis. The authors are interested in the use of a biological dosimeter of microorganisms which can directly compare biological effects such as survival level. The survival rate of yeast cells was tested for this purpose with a carbon beam at 135 MeV/amu from the RIKEN ring cyclotron. The haploid cells of a wild type and a radiation sensitive mutant were used. Yeast is a simple eukaryote, and it has been used as the test organism especially for the studies on the relation between DNA double-strand breaks and cell killing. The materials used, the experimental method and the results are reported. The survival data of the wild type and the radiation sensitive mutant at stationary and log phases were obtained, and the values were used for the RBE estimation. The resistance seemed due to the action of enzymatic repair mechanism. (K.I.)

  10. Advancing medicine one research note at a time: the educational value in clinical case reports

    Directory of Open Access Journals (Sweden)

    Cabán-Martinez Alberto J

    2012-07-01

    Full Text Available Abstract A case report—a brief written note that describes unique aspects of a clinical case—provides a significant function in medicine given its rapid, succinct, and educational contributions to scientific literature and clinical practice. Despite the growth of, and emphasis on, randomized clinical trials and evidenced-based medicine, case reports continue to provide novel and exceptional knowledge in medical education. The journal BMC Research Notes introduces a new “case reports” section to provide the busy clinician with a forum in which to document any authentic clinical case that provide educational value to current clinical practice. The aim is for this article type to be reviewed, wherever possible, by specialized Associate Editors for the journal, in order to provide rapid but thorough decision making. New ideas often garnered by and documented in case reports will support the advancement of medical science — one research note at a time.

  11. Don't just do something, stand there! The value and art of deliberate clinical inertia.

    Science.gov (United States)

    Keijzers, Gerben; Cullen, Louise; Egerton-Warburton, Diana; Fatovich, Daniel M

    2018-04-01

    It can be difficult to avoid unnecessary investigations and treatments, which are a form of low-value care. Yet every intervention in medicine has potential harms, which may outweigh the potential benefits. Deliberate clinical inertia is the art of doing nothing as a positive response. This paper provides suggestions on how to incorporate deliberate clinical inertia into our daily clinical practice, and gives an overview of current initiatives such as 'Choosing Wisely' and the 'Right Care Alliance'. The decision to 'do nothing' can be complex due to competing factors, and barriers to implementation are highlighted. Several strategies to promote deliberate clinical inertia are outlined, with an emphasis on shared decision-making. Preventing medical harm must become one of the pillars of modern health care and the art of not intervening, that is, deliberate clinical inertia, can be a novel patient-centred quality indicator to promote harm reduction. © 2018 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  12. The relative biological effectiveness of fractionated doses of fast neutrons (42 MeV sub d yields Be ) for normal tissues. Pt. 3; Effects on lung function

    Energy Technology Data Exchange (ETDEWEB)

    Rezvani, M.; Hopewell, J.W.; Robbins, M.E.C.; Hamlet, R. (Churchill Hospital, Oxford (UK)); Barnes, D.W.H.; Sansom, J.M.; Adams, P.J.V. (Medical Research Council, Harwell (UK). Radiobiological Research Unit)

    1990-11-01

    The effect of single and fractionated doses of fast neutrons (42 MeV{sub d{yields}Bc}) on the early and late radiation responses of the pig lung have been assessed by the measurement of changes in lung function using a {sup 133}Xe washout technique. The results obtained for irradiation schedules with fast neutrons have been compared with those after photon irradiation. There was no statistically significant difference between the values for the relative biological effectiveness (RBE) for the early and late radiation response of the lung. The RBE of the neutron beam increased with decreasing size of dose/fraction with an upper limit value of 4.39 {plus minus} 0.94 for infinitely small X-ray doses per fraction. (author).

  13. Disruption of SLX4-MUS81 Function Increases the Relative Biological Effectiveness of Proton Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi [Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Underwood, Tracy S.A.; Kung, Jong [Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Wang, Meng [Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Lu, Hsiao-Ming; Paganetti, Harald [Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Held, Kathryn D.; Hong, Theodore S.; Efstathiou, Jason A. [Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Willers, Henning, E-mail: hwillers@mgh.harvard.edu [Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-05-01

    Purpose: Clinical proton beam therapy has been based on the use of a generic relative biological effectiveness (RBE) of ∼1.1. However, emerging data have suggested that Fanconi anemia (FA) and homologous recombination pathway defects can lead to a variable RBE, at least in vitro. We investigated the role of SLX4 (FANCP), which acts as a docking platform for the assembly of multiple structure-specific endonucleases, in the response to proton irradiation. Methods and Materials: Isogenic cell pairs for the study of SLX4, XPF/ERCC1, MUS81, and SLX1 were irradiated at the mid-spread-out Bragg peak of a clinical proton beam (linear energy transfer 2.5 keV/μm) or with 250 kVp x-rays, and the clonogenic survival fractions were determined. To estimate the RBE of the protons relative to cobalt-60 photons (Co60Eq), we assigned a RBE(Co60Eq) of 1.1 to x-rays to correct the physical dose measured. Standard DNA repair foci assays were used to monitor the damage responses, and the cell cycle distributions were assessed by flow cytometry. The poly(ADP-ribose) polymerase inhibitor olaparib was used for comparison. Results: Loss of SLX4 function resulted in an enhanced proton RBE(Co60Eq) of 1.42 compared with 1.11 for wild-type cells (at a survival fraction of 0.1; P<.05), which correlated with increased persistent DNA double-strand breaks in cells in the S/G{sub 2} phase. Genetic analysis identified the SLX4-binding partner MUS81 as a mediator of resistance to proton radiation. Both proton irradiation and olaparib treatment resulted in a similar prolonged accumulation of RAD51 foci in SLX4/MUS81-deficient cells, suggesting a common defect in the repair of DNA replication fork-associated damage. Conclusions: A defect in the FA pathway at the level of SLX4 results in hypersensitivity to proton radiation, which is, at least in part, due to impaired MUS81-mediated processing of replication forks that stall at clustered DNA damage. In vivo and clinical studies are needed to

  14. Clinical Correlates and Prognostic Value of Proenkephalin in Acute and Chronic Heart Failure.

    Science.gov (United States)

    Matsue, Yuya; Ter Maaten, Jozine M; Struck, Joachim; Metra, Marco; O'Connor, Christopher M; Ponikowski, Piotr; Teerlink, John R; Cotter, Gad; Davison, Beth; Cleland, John G; Givertz, Michael M; Bloomfield, Daniel M; Dittrich, Howard C; van Veldhuisen, Dirk J; van der Meer, Peter; Damman, Kevin; Voors, Adriaan A

    2017-03-01

    Proenkephalin (pro-ENK) has emerged as a novel biomarker associated with both renal function and cardiac function. However, its clinical and prognostic value have not been well evaluated in symptomatic patients with heart failure. The association between pro-ENK and markers of renal function was evaluated in 95 patients with chronic heart failure who underwent renal hemodynamic measurements, including renal blood flow (RBF) and glomerular filtration rate (GFR) with the use of 131 I-Hippuran and 125 I-iothalamate clearances, respectively. The association between pro-ENK and clinical outcome in acute heart failure was assessed in another 1589 patients. Pro-ENK was strongly correlated with both RBF (P renal tubular markers. In the acute heart failure cohort, pro-ENK was a predictor of death through 180 days, heart failure rehospitalization through 60 days, and death or cardiovascular or renal rehospitalization through day 60 in univariable analyses, but its predictive value was lost in a multivariable model when other renal markers were entered in the model. In patients with chronic and acute heart failure, pro-ENK is strongly associated with glomerular function, but not with tubular damage. Pro-ENK provides limited prognostic information in patients with acute heart failure on top of established renal markers. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Outcomes and Acute Toxicities of Proton Therapy for Pediatric Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System

    International Nuclear Information System (INIS)

    McGovern, Susan L.; Okcu, M. Fatih; Munsell, Mark F.; Kumbalasseriyil, Nancy; Grosshans, David R.; McAleer, Mary F.; Chintagumpala, Murali; Khatua, Soumen; Mahajan, Anita

    2014-01-01

    Purpose: Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a rare cancer primarily affecting children younger than 5 years old. Because patients are young and receive intensive chemotherapy, there is concern regarding late radiation toxicity, particularly as survival rates improve. Therefore, there is interest in using proton therapy to treat these tumors. This study was undertaken to investigate outcomes and acute toxicities associated with proton therapy for AT/RT. Methods and Materials: The records of 31 patients with AT/RT treated with proton radiation from October 2008 to August 2013 were reviewed. Demographics, treatment characteristics, and outcomes were recorded and analyzed. Results: Median age at diagnosis was 19 months (range, 4-55 months), with a median age at radiation start of 24 months (range, 6-62 months). Seventeen patients received local radiation with a median dose of 50.4 GyRBE (range, 9-54 GyRBE). Fourteen patients received craniospinal radiation; half received 24 GyRBE or less, and half received 30.6 GyRBE or more. For patients receiving craniospinal radiation, the median tumor dose was 54 GyRBE (range, 43.2-55.8 GyRBE). Twenty-seven patients (87%) completed the planned radiation. With median follow-up of 24 months for all patients (range, 3-53 months), median progression-free survival was 20.8 months and median overall survival was 34.3 months. Five patients (16%) developed clinical findings and imaging changes in the brainstem 1 to 4 months after radiation, consistent with radiation reaction; all cases resolved with steroids or bevacizumab. Conclusions: This is the largest report of children with AT/RT treated with proton therapy. Preliminary survival outcomes in this young pediatric population are encouraging compared to historic results, but further study is warranted

  16. Outcomes and Acute Toxicities of Proton Therapy for Pediatric Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, Susan L., E-mail: slmcgove@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Okcu, M. Fatih [Texas Children' s Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kumbalasseriyil, Nancy; Grosshans, David R.; McAleer, Mary F. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chintagumpala, Murali [Texas Children' s Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas (United States); Khatua, Soumen [Department of Pediatrics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mahajan, Anita [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-12-01

    Purpose: Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a rare cancer primarily affecting children younger than 5 years old. Because patients are young and receive intensive chemotherapy, there is concern regarding late radiation toxicity, particularly as survival rates improve. Therefore, there is interest in using proton therapy to treat these tumors. This study was undertaken to investigate outcomes and acute toxicities associated with proton therapy for AT/RT. Methods and Materials: The records of 31 patients with AT/RT treated with proton radiation from October 2008 to August 2013 were reviewed. Demographics, treatment characteristics, and outcomes were recorded and analyzed. Results: Median age at diagnosis was 19 months (range, 4-55 months), with a median age at radiation start of 24 months (range, 6-62 months). Seventeen patients received local radiation with a median dose of 50.4 GyRBE (range, 9-54 GyRBE). Fourteen patients received craniospinal radiation; half received 24 GyRBE or less, and half received 30.6 GyRBE or more. For patients receiving craniospinal radiation, the median tumor dose was 54 GyRBE (range, 43.2-55.8 GyRBE). Twenty-seven patients (87%) completed the planned radiation. With median follow-up of 24 months for all patients (range, 3-53 months), median progression-free survival was 20.8 months and median overall survival was 34.3 months. Five patients (16%) developed clinical findings and imaging changes in the brainstem 1 to 4 months after radiation, consistent with radiation reaction; all cases resolved with steroids or bevacizumab. Conclusions: This is the largest report of children with AT/RT treated with proton therapy. Preliminary survival outcomes in this young pediatric population are encouraging compared to historic results, but further study is warranted.

  17. Clinical workplace learning: perceived learning value of individual and group feedback in a collectivistic culture.

    Science.gov (United States)

    Suhoyo, Yoyo; Schönrock-Adema, Johanna; Emilia, Ova; Kuks, Jan B M; Cohen-Schotanus, Janke

    2018-04-19

    Feedback is essential for workplace learning. Most papers in this field concern individual feedback. In collectivistic cultures, however, group feedback is common educational practice. This study was conducted to investigate the perceived learning value and characteristics of individual and group feedback in a collectivistic culture. During two weeks, on a daily basis, clerkship students (n = 215) from 12 clinical departments at Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia, recorded individual and group feedback moments by using a structured form: the providers, focus and perceived learning value of feedback. Data were analysed with logistic regression and multilevel techniques. Students reported 2687 group and 1535 individual feedback moments. Group feedback more often focused on history taking, clinical judgment, patient management, patient counselling, and professional behaviour (OR ranging from 1.232, p cultures, group feedback may add to the array of educational measures that optimize student learning. Congruence between culture and type of feedback may be important for the effectiveness of feedback.

  18. Sulforaphane induces cell cycle arrest by protecting RB-E2F-1 complex in epithelial ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Morris Robert

    2010-03-01

    Full Text Available Abstract Background Sulforaphane (SFN, an isothiocyanate phytochemical present predominantly in cruciferous vegetables such as brussels sprout and broccoli, is considered a promising chemo-preventive agent against cancer. In-vitro exposure to SFN appears to result in the induction of apoptosis and cell-cycle arrest in a variety of tumor types. However, the molecular mechanisms leading to the inhibition of cell cycle progression by SFN are poorly understood in epithelial ovarian cancer cells (EOC. The aim of this study is to understand the signaling mechanisms through which SFN influences the cell growth and proliferation in EOC. Results SFN at concentrations of 5 - 20 μM induced a dose-dependent suppression of growth in cell lines MDAH 2774 and SkOV-3 with an IC50 of ~8 μM after a 3 day exposure. Combination treatment with chemotherapeutic agent, paclitaxel, resulted in additive growth suppression. SFN at ~8 μM decreased growth by 40% and 20% on day 1 in MDAH 2774 and SkOV-3, respectively. Cells treated with cytotoxic concentrations of SFN have reduced cell migration and increased apoptotic cell death via an increase in Bak/Bcl-2 ratio and cleavage of procaspase-9 and poly (ADP-ribose-polymerase (PARP. Gene expression profile analysis of cell cycle regulated proteins demonstrated increased levels of tumor suppressor retinoblastoma protein (RB and decreased levels of E2F-1 transcription factor. SFN treatment resulted in G1 cell cycle arrest through down modulation of RB phosphorylation and by protecting the RB-E2F-1 complex. Conclusions SFN induces growth arrest and apoptosis in EOC cells. Inhibition of retinoblastoma (RB phosphorylation and reduction in levels of free E2F-1 appear to play an important role in EOC growth arrest.

  19. TH-CD-209-06: LET-Based Adjustment of IMPT Plans Using Prioritized Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, J; Giantsoudi, D; Paganetti, H [Massachusetts General Hospital, Boston, MA (United States); Botas, P [Massachusetts General Hospital, Boston, MA (United States); Heidelberg University, Heidelberg, DE (Germany); Qin, N; Jia, X [The University of Texas Southwestern Medical Ctr, Dallas, TX (United States)

    2016-06-15

    Purpose: In-vitro experiments suggest an increase in proton relative biological effectiveness (RBE) towards the end of range. However, proton treatment planning and dose reporting for clinical outcome assessment has been based on physical dose and constant RBE. Therefore, treatment planning for intensity-modulated proton therapy (IMPT) is unlikely to transition radically to pure RBE-based planning. We suggest a hybrid approach where treatment plans are initially created based on physical dose constraints and prescriptions, and are subsequently altered to avoid high linear energy transfer (LET) in critical structures while limiting the degradation of the physical dose distribution. Methods: To allow fast optimization based on dose and LET we extended a GPU-based Monte-Carlo code towards providing dose-averaged LET in addition to dose for all pencil beams. After optimizing an initial IMPT plan based on physical dose, a prioritized optimization scheme is used to modify the LET distribution while constraining the physical dose objectives to values close to the initial plan. The LET optimization step is performed based on objective functions evaluated for the product of physical dose and LET (LETxD). To first approximation, LETxD represents a measure of the additional biological dose that is caused by high LET. Regarding optimization techniques, LETxD has the advantage of being a linear function of the pencil beam intensities. Results: The method is applicable to treatments where serial critical structures with maximum dose constraint are located in or near the target. We studied intra-cranial tumors (high-grade meningiomas, base-of-skull chordomas) where the target (CTV) overlaps with the brainstem and optic structures. Often, high LETxD in critical structures can be avoided while minimally compromising physical dose planning objectives. Conclusion: LET-based re-optimization of IMPT plans represents a pragmatic approach to bridge the gap between purely physical dose

  20. Biological intercomparison using gut crypt survivals for proton and carbon-ion beams

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Furusawa, Yoshiya

    2007-01-01

    Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or RBE for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, biological endpoint, dose and fractionation schedule, a single RBE value could not deal with all different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance<2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between National Institute of Radiological Sciences (NIRS)/ Heavy Ion Medical Accelerator in Chiba (HIMAC) and Gesellschaft fur Schwerionenforschung (GSI)/Heavy Ion Synchrotron (SIS) was 1% for three positions within the 6-cm SOBP. The coefficient of variance was <1.7, <0.6 and <1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival. (author)

  1. Microdosimetric evaluation of relative biological effectiveness for 103PD, 125I, 241AM, and 192IR brachytherapy sources

    International Nuclear Information System (INIS)

    Wuu, C.S.; Kliauga, P.; Zaider, M.; Amols, H.I.

    1996-01-01

    Purpose: To determine the microdosimetric-derived relative biological effectiveness (RBE) of 103 Pd, 125 I, 241 Am, and 192 Ir brachytherapy sources at low doses and/or low dose rates. Methods and Materials: The Theory of Dual Radiation Action can be used to predict expected RBE values based on the spatial distribution of energy deposition at microscopic levels from these sources. Single-event lineal energy spectra for these isotopes have been obtained both experimentally and theoretically. A grid-defined wall-less proportional counter was used to measure the lineal energy distributions. Unlike conventional Rossi proportional counters, the counter used in these measurements has a conducting nylon fiber as the central collecting anode and has no metal parts. Thus, the Z-dependence of the photoelectric effect is eliminated as a source of measurement error. Single-event spectra for these brachytherapy sources have been also calculated by: (a) the Monte Carlo code MCNP to generate the electron slowing down spectrum, (b) transport of monoenergetic electron tracks, event by event, with our Monte Carlo code DELTA, (c) using the concept of associated volume to obtain the lineal energy distribution f(y) for each monoenergetic electron, and (d) obtaining the composite lineal energy spectrum for a given brachytherapy source based on the electron spectrum calculated at step (a). Results: Relative to 60 Co, the RBE values obtained from this study are: 2.3 for 103 Pd, 2.1 for 125 I, 2.1 for 241 Am, and 1.3 for 192 Ir. Conclusions: These values are consistent with available data from in vitro cell survival experiments. We suggest that, at least for these brachytherapy sources, microdosimetry may be used as a credible alternative to time-consuming (and often uncertain) radiobiological experiments to obtain information on radition quality and make reliable predictions of RBE in low dose rate brachytherapy

  2. Biological intercomparison using gut crypt survivals for proton and carbon ions

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Furusawa, Yoshiya

    2006-01-01

    Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or relative biological effectiveness (RBE) for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, endpoint, dose and fractionation schedule, a single RBE value could not function as a master key to open all rooms filled with guests of different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance <2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between National Institute of Radiological Sciences (NIRS)/Heavy Ion Medical Accelerator in Chiba (HIMAC) and Gesellschaft fur Schwerionenforschung (GSI)/Heavy Ion Synchrotron (SIS) was 1% for three positions within the 6-cm SOBP. The coefficient of variance was <1.7, <0.6 and <1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival. (author)

  3. Assessment of potential advantages of relevant ions for particle therapy: A model based study

    Energy Technology Data Exchange (ETDEWEB)

    Grün, Rebecca, E-mail: r.gruen@gsi.de [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390 (Germany); Medical Faculty of Philipps-University Marburg, Marburg 35032 (Germany); Friedrich, Thomas; Krämer, Michael; Scholz, Michael [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Zink, Klemens [Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany); Durante, Marco [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany and Department of Condensed Matter Physics, Darmstadt University of Technology, Darmstadt 64289 (Germany); Engenhart-Cabillic, Rita [Medical Faculty of Philipps-University Marburg, Marburg 35032, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany)

    2015-02-15

    Purpose: Different ion types offer different physical and biological advantages for therapeutic applications. The purpose of this work is to assess the advantages of the most commonly used ions in particle therapy, i.e., carbon ({sup 12}C), helium ({sup 4}He), and protons ({sup 1}H) for different treatment scenarios. Methods: A treatment planning analysis based on idealized target geometries was performed using the treatment planning software TRiP98. For the prediction of the relative biological effectiveness (RBE) that is required for biological optimization in treatment planning the local effect model (LEM IV) was used. To compare the three ion types, the peak-to-entrance ratio (PER) was determined for the physical dose (PER{sub PHY} {sub S}), the RBE (PER{sub RBE}), and the RBE-weighted dose (PER{sub BIO}) resulting for different dose-levels, field configurations, and tissue types. Further, the dose contribution to artificial organs at risk (OAR) was assessed and a comparison of the dose distribution for the different ion types was performed for a patient with chordoma of the skull base. Results: The study showed that the advantages of the ions depend on the physical and biological properties and the interplay of both. In the case of protons, the consideration of a variable RBE instead of the clinically applied generic RBE of 1.1 indicates an advantage in terms of an increased PER{sub RBE} for the analyzed configurations. Due to the fact that protons show a somewhat better PER{sub PHY} {sub S} compared to helium and carbon ions whereas helium shows a higher PER{sub RBE} compared to protons, both protons and helium ions show a similar RBE-weighted dose distribution. Carbon ions show the largest variation of the PER{sub RBE} with tissue type and a benefit for radioresistant tumor types due to their higher LET. Furthermore, in the case of a two-field irradiation, an additional gain in terms of PER{sub BIO} is observed when using an orthogonal field configuration

  4. Evaluation of Diagnostic Values of Clinical Assessment in Determining the Maturation of Arteriovenous Fistulas for Satisfactory Hemodialysis.

    Science.gov (United States)

    Salimi, Fereshteh; Shahabi, Shahab; Talebzadeh, Hamid; Keshavarzian, Amir; Pourfakharan, Mohammad; Safaei, Mansour

    2017-01-01

    Fistulas are the preferred permanent hemodialysis vascular access, but a significant obstacle to increasing their prevalence is the fistula's high "failure to mature" (FTM) rate. This study aimed to identify postoperative clinical characteristics that are predictive of fistula FTM. This descriptive cross-sectional study was performed on 80 end-stage renal disease patients who referred to Al Zahra Hospital, Isfahan, for brachiocephalic fistula placement. After 4 weeks, the clinical criteria (trill, firmness, vein length, and venous engorgement) examined and the fistulas situation divided to favorable or unfavorable by each criterion, and the results comprised with dialysis possibility. Data were analyzed with SPSS version 21. Diagnostic index for CLINICAL examination was calculated. Among the 80 cases, 25 (31.2%) female and 55 (68.8%) male were studied with the mean age of 51.9 (standard deviation = 17) year ranged between 18 and 86 years old. Sixty-two (77.5%) cases had successful hemodialysis. All four clinical assessments were significantly more acceptable in patients with successful dialysis ( P < 0.001). According to the results of our study, the accuracy of all physical assessments was above 70% and except vein length other criteria had a sensitivity and negative predictive value of 100%. In this study, firmness of vein has highest specificity and positive predictive value (83.9% and 64.3%, respectively). Results of our study showed that high sensitivity and relatively low specificity of the clinical criterion. It means that unfavorable results of each clinical criterion predict unfavorable dialysis. Clinical evaluation of a newly created fistula 4-6 weeks after surgery should be considered mandatory.

  5. RBE determination of tumors by serum aldolase

    Energy Technology Data Exchange (ETDEWEB)

    Dalluege, K H [Akademie der Wissenschaften der DDR, Berlin. Zentralinstitut fuer Krebsforschung

    1981-06-01

    In patients with histologically ascertained bronchial carcinoma the tumor volume and the plasma volume was determined before therapy. Following the first irradiation of the tumor with a /sup 60/Co pendulum technique over the diseased side with 5 Gy for the 80% isodose determination of aldolase and creatin kinase was performed frequently during 24 h. A peak of serum aldolase was found 16 - 18 h after irradiation. The aldolase values of this peak were higher for undifferentiated carcinomas than for squamous cell carcinomas and proportional to the size of the tumor. The hypothesis is made that by means of this method using different radiation qualities their 'relative biological effectiveness' can be determined.

  6. Cell transformation in vitro by fast neutrons of different energies: implications for mechanisms

    International Nuclear Information System (INIS)

    Barendsen, G.W.; Gaiser, J.F.

    1985-01-01

    Studies have been performed to analyse the dependence of the induction of cell transformation and cell reproductive death in cultures of C3H/10T1/2 cells, NBCH-3 cells and WAGR-2 cells on the energy of mono-energetic fast neutrons. The dose-effect relations for 300 kV, 4.2 MeV X rays, 15 MeV and 0.5 MeV neutrons have been analysed on the basis of the representations F(D) = t 1 D+t 2 D 2 and S(D)/S(0) = exp [-a 1 D+a 2 D 2 )] for transformation and survival respectively. The results show that a 1 values for all radiations are a factor of approximately 10 3 larger than corresponding t 1 values. The RBE values for cell reproductive death derived as ratios of a 1 for the various neutrons and 300 kV x rays are similar to the corresponding RBE values for cell transformation derived as ratios of t 1 values of neutrons and X rays. These similarities in the RBE values and differences in absolute values of a 1 and t 1 can be compared with results from published dose-effect relations for reproductive death and chromosome aberrations obtained for other cell lines. The insights obtained can be applied to derive a hypothesis about the induction of these effects, assuming similarities in energy requirements and physico-chemical primary mechanisms of the induction of damage in chromosomes and differences in the specificities of the sites and total size of the targets on chromosomes associated with the various endpoints observed. (author)

  7. Biological effectiveness of neutron irradiation on animals and man

    Energy Technology Data Exchange (ETDEWEB)

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, /sup 252/Cf-fission, and 15 MeV neutrons, compared with that by /sup 60/Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use.

  8. Biological effectiveness of neutron irradiation on animals and man

    International Nuclear Information System (INIS)

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, 252 Cf-fission, and 15 MeV neutrons, compared with that by 60 Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use

  9. Analysis of postoperative biochemical values and clinical outcomes after adrenalectomy for primary aldosteronism.

    Science.gov (United States)

    Swearingen, Andrew J; Kahramangil, Bora; Monteiro, Rosebel; Krishnamurthy, Vikram; Jin, Judy; Shin, Joyce; Siperstein, Allan; Berber, Eren

    2018-04-01

    Primary aldosteronism causes hypertension and hypokalemia and is often surgically treatable. Diagnosis includes elevated plasma aldosterone, suppressed plasma renin activity, and elevated aldosterone renin ratio. Adrenalectomy improves hypertension and hypokalemia. Postoperative plasma aldosterone and plasma renin activity may be useful in documenting cure or failure. A retrospective analysis of patients who underwent adrenalectomy for primary aldosteronism from 2010 to 2016 was performed, analyzing preoperative and postoperative plasma aldosterone, plasma renin activity, hypertension, and hypokalemia. The utility of postoperative testing was assessed. Clinical cure was defined as improved hypertension control and resolution of potassium loss. Biochemical cure was defined as aldosterone renin ratio reduction to <23.6. Forty-four patients were included; 20 had plasma aldosterone and plasma renin activity checked on postoperative day 1. In the study, 40/44 (91%) were clinically cured. All clinical failures had of biochemical failure at follow-up. Postoperative day 1aldosterone renin ratio <23.6 had PPV of 95% for clinical cure. Cured patients had mean plasma aldosterone drop of 33.1 ng/dL on postoperative day 1; noncured patient experienced 3.9 ng/dL increase. A cutoff of plasma aldosterone decrease of 10 ng/dL had high positive predictive value for clinical cure. Changes in plasma aldosterone and plasma renin activity after adrenalectomy correlate with improved hypertension and hypokalemia. The biochemical impact of adrenalectomy manifests as early as postoperative day 1. We propose a plasma aldosterone decrease of 10 ng/dL as a criterion to predict clinical cure. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Analysis of the radiation related morbidity observed in a randomized trial of neutron therapy for bladder cancer

    International Nuclear Information System (INIS)

    Duncan, W.; Williams, J.R.; Kerr, G.R.; Arnott, S.J.; Quilty, P.M.; Rodger, A.; MacDougall, R.H.; Jack, W.J.

    1986-01-01

    This report is an analysis of the morbidity in the bladder and bowel observed in a randomized trial of d(15)+Be neutrons versus megavoltage photons in the treatment of bladder cancer. Acute reactions in the bladder and bowel were significantly worse after photon therapy. Of the patients treated with photons 45.7% had severe reactions in the bladder compared with 10.6% after neutron therapy (p less than 0.001). Severe acute bowel reactions were observed in 8.5% of the patients after photon therapy compared with 3.8% after neutron therapy (p less than 0.05). Late reactions were significantly worse after neutrons. Severe late reactions in the bladder were seen in 58.5% of patients after neutron therapy and in 40.5% after photon therapy (p less than 0.05). In the bowel they were observed in 53.3% of patients after neutron therapy compared with 8% after photon therapy (p less than 0.0001). The disparity in the degree of early and late complications makes assessment of RBE values difficult. It is estimated that for bladder morbidity the RBE value, for photon dose fractions of 2.75 Gy, is less than 3.3 for early reactions and equal to 3.4 for late effects. The respective RBE values for early and late effects in the bowel are less than 3.4 and 3.8

  11. Clinical value of detection of serum β-Crosslaps, PINP and N-MID in postmenopausal women with osteoporosis

    International Nuclear Information System (INIS)

    Ou Mengmeng; Huang Jianrong

    2011-01-01

    To evaluate the clinical value of detection of concentration of β-Crosslaps, PINP and N-MID in postmenopausal women with osteoporosis, 116 postmenopausal women were detected by dual X-ray absorptionmetry and divided into NOP group (51 cases) and OP group (65 cases). The serum levels of three bone markers (β-Crosslaps, PINP and N-MID) were measured. The results showed that serum levels of β-Crosslaps, PINP and N-MID in OP group were significantly higher than that in NOP group (P<0.01). It was suggested that three bone markers level might be closely related with osteoporosis in postmenopausal women. The combined detection of bone markers and bone mineral density has important clinical value in the diagnosis of osteoporosis in postmenopausal women. (authors)

  12. Developing a framework to guide the de-adoption of low-value clinical practices in acute care medicine: a study protocol.

    Science.gov (United States)

    Parsons Leigh, Jeanna; Niven, Daniel J; Boyd, Jamie M; Stelfox, Henry T

    2017-01-19

    Healthcare systems have difficulty incorporating scientific evidence into clinical practice, especially when science suggests that existing clinical practices are of low-value (e.g. ineffective or harmful to patients). While a number of lists outlining low-value practices in acute care medicine currently exist, less is known about how best to initiate and sustain the removal of low-value clinical practices (i.e. de-adoption). This study will develop a comprehensive list of barriers and facilitators to the de-adoption of low-value clinical practices in acute care facilities to inform the development of a framework to guide the de-adoption process. The proposed project is a multi-stage mixed methods study to develop a framework to guide the de-adoption of low-value clinical practices in acute care medicine that will be tested in a representative sample of acute care settings in Alberta, Canada. Specifically, we will: 1) conduct a systematic review of the de-adoption literature to identify published barriers and facilitators to the de-adoption of low-value clinical practices in acute care medicine and any associated interventions proposed (Phase one); 2) conduct focus groups with acute care stakeholders to identify important themes not published in the literature and obtain a comprehensive appreciation of stakeholder perspectives (Phase two); 3) extend the generalizability of focus group findings by conducting individual stakeholder surveys with a representative sample of acute care providers throughout the province to determine which barriers and facilitators identified in Phases one and two are most relevant in their clinical setting (Phase three). Identified barriers and facilitators will be catalogued and integrated with targeted interventions in a framework to guide the process of de-adoption in each of four targeted areas of acute care medicine (Emergency Medicine, Cardiovascular Health and Stroke, Surgery and Critical Care Medicine). Analyses will be

  13. Optimization of Monte Carlo particle transport parameters and validation of a novel high throughput experimental setup to measure the biological effects of particle beams.

    Science.gov (United States)

    Patel, Darshana; Bronk, Lawrence; Guan, Fada; Peeler, Christopher R; Brons, Stephan; Dokic, Ivana; Abdollahi, Amir; Rittmüller, Claudia; Jäkel, Oliver; Grosshans, David; Mohan, Radhe; Titt, Uwe

    2017-11-01

    Accurate modeling of the relative biological effectiveness (RBE) of particle beams requires increased systematic in vitro studies with human cell lines with care towards minimizing uncertainties in biologic assays as well as physical parameters. In this study, we describe a novel high-throughput experimental setup and an optimized parameterization of the Monte Carlo (MC) simulation technique that is universally applicable for accurate determination of RBE of clinical ion beams. Clonogenic cell-survival measurements on a human lung cancer cell line (H460) are presented using proton irradiation. Experiments were performed at the Heidelberg Ion Therapy Center (HIT) with support from the Deutsches Krebsforschungszentrum (DKFZ) in Heidelberg, Germany using a mono-energetic horizontal proton beam. A custom-made variable range selector was designed for the horizontal beam line using the Geant4 MC toolkit. This unique setup enabled a high-throughput clonogenic assay investigation of multiple, well defined dose and linear energy transfer (LETs) per irradiation for human lung cancer cells (H460) cultured in a 96-well plate. Sensitivity studies based on application of different physics lists in conjunction with different electromagnetic constructors and production threshold values to the MC simulations were undertaken for accurate assessment of the calculated dose and the dose-averaged LET (LET d ). These studies were extended to helium and carbon ion beams. Sensitivity analysis of the MC parameterization revealed substantial dependence of the dose and LET d values on both the choice of physics list and the production threshold values. While the dose and LET d calculations using FTFP_BERT_LIV, FTFP_BERT_EMZ, FTFP_BERT_PEN and QGSP_BIC_EMY physics lists agree well with each other for all three ions, they show large differences when compared to the FTFP_BERT physics list with the default electromagnetic constructor. For carbon ions, the dose corresponding to the largest LET d

  14. RBEs and cytogenetic hereditary effects induced by neutron beams in mice

    International Nuclear Information System (INIS)

    Du Zeji; Li Yanyi; Liu Degui

    1994-01-01

    The RBEs and cytogenetic hereditary effects of different dose of neutron beams on chromosome aberrations and micronuclei of bone marrow cells in mice were observed. The results indicated that micronuclei frequency of occurrence and chromosome aberration frequency caused by neutrons increased with doses. The relationship was feasible to Y aD n . The lower energy of neutrons had the smaller value of RBE. RBE determined by CSACR were larger than that by MNCF. RBEs decreased with increasing of neutron doses, especially within the low range of doses. There was a linear relationship between CSACR and MNCF caused by neutron beams and γ-ray

  15. Negative pion irradiation of mammalian cells

    International Nuclear Information System (INIS)

    Dertinger, H.; Luecke-Huhle, C.; Schlag, H.; Weibezahn, K.F.

    1976-01-01

    Monolayers and spheroids of Chinese hamster cells (V79) were subjected to negative pion irradiation under aerobic conditions. R.b.e. values in the pion peak of 1.8 and 1.5 were obtained for monolayers and spheroids, respectively, whereas the r.b.e. for the plateau was found to be slightly higher than 1. In addition, it was observed that the higher resistance of the V79 spheroid cells than the monolayers to γ-irradiation is not diminished in the pion peak, suggesting that the underlying phenomenon of intercellular communication influences cell survival even after high-LET irradiation. (author)

  16. Clinical value of arteriography in postpartum hemorrhage by transcatheter arterial embolization

    International Nuclear Information System (INIS)

    Wang Kai; Jiang Guomin; Zhao Jinwei; Huang Wenhua; Liu Yizhi; Jin Yonghai

    2010-01-01

    Objective: To analyze the arterial supply in postpartum hemorrhage and to evaluate the clinical value of arteriography in transcatheter arterial embolization (TAE) for treating postpartum hemorrhage. Methods: The arteriography of 37 patients with postpartum hemorrhage was analyzed. TAE were performed after the bleeding artery was identified. Post TAE angiography was performed to confirm the success of embolization. Results: The bleeding artery in atonic uterus and abnormal placenta was the uterine artery. The bleeding artery in birth canal laceration is mainly non-uterine artery. Postpartum hemorrhage was successfully controlled in all 37 patients without sever complication of TAE. Conclusion: Arteriography in postpartum hemorrhage can demonstrate the bleeding artery and is potential collaterals allowing adequate embolization without complication. (authors)

  17. The protons of space and brain tumors: I. Clinical and dosimetric considerations

    International Nuclear Information System (INIS)

    Dalrymple, G.V.; Nagle, W.A.; Moss, A.J.; Cavin, L.A.; Broadwater, J.R.; McGuire, E.L.; Eason, C.S.

    1989-01-01

    Almost 25 years ago a large group of Rhesus monkeys were irradiated with protons (32--2300 MeV). The experiments were designed: (1) To estimate the RBE of protons, per se, and (2) To provide some estimate of the hazards of the radiation environment of space. The initial results showed the RBE to be about 1.0 for acute radiation effects (mortality, hematologic changes, etc). The colony has been maintained at Brooks AFB, TX since irradiation. The survivors of 55 MeV proton irradiation have developed a very high incidence of Glioblastoma multiforme, a highly malignant primary brain tumor. These tumors appeared 1--20 yrs after surface doses of 400--800 rads. Reconstruction of the dosimetry suggests that some areas within the brain may have received doses of 1500--2500 rads. More than 30 radiation induced Glioblastomas have been reported in human patients who had received therapeutic head irradiation. The radiation doses required to induce Glioblastoma were of the same order of magnitude as required to induce Glioblastoma in the Rhesus monkey

  18. A counterfactual p-value approach for benefit-risk assessment in clinical trials.

    Science.gov (United States)

    Zeng, Donglin; Chen, Ming-Hui; Ibrahim, Joseph G; Wei, Rachel; Ding, Beiying; Ke, Chunlei; Jiang, Qi

    2015-01-01

    Clinical trials generally allow various efficacy and safety outcomes to be collected for health interventions. Benefit-risk assessment is an important issue when evaluating a new drug. Currently, there is a lack of standardized and validated benefit-risk assessment approaches in drug development due to various challenges. To quantify benefits and risks, we propose a counterfactual p-value (CP) approach. Our approach considers a spectrum of weights for weighting benefit-risk values and computes the extreme probabilities of observing the weighted benefit-risk value in one treatment group as if patients were treated in the other treatment group. The proposed approach is applicable to single benefit and single risk outcome as well as multiple benefit and risk outcomes assessment. In addition, the prior information in the weight schemes relevant to the importance of outcomes can be incorporated in the approach. The proposed CPs plot is intuitive with a visualized weight pattern. The average area under CP and preferred probability over time are used for overall treatment comparison and a bootstrap approach is applied for statistical inference. We assess the proposed approach using simulated data with multiple efficacy and safety endpoints and compare its performance with a stochastic multi-criteria acceptability analysis approach.

  19. Interexaminer reliability in clinical measurement of L*C*h* values of anterior teeth using a spectrophotometer.

    Science.gov (United States)

    Hassel, Alexander J; Grossmann, Anne-christiane; Schmitter, Marc; Balke, Zibandeh; Buzello, Anja M

    2007-01-01

    The objective of this study was to investigate interexaminer reliability in the clinical measurement of the L*C*h* (lightness/value, chroma, hue) values of anterior teeth using a spectrophotometer (Vita Easyshade). The basic color of the maxillary right central incisors and canines of 23 subjects was spectrophotometrically determined by 4 clinicians and an experienced user (development manager) of the spectrophotometer. Also, to analyze the effect of different training with the instrument on interexaminer reliability, 2 of the clinicians were instructed in the use of the spectrophotometer by the experienced examiner, whereas the others instructed themselves by studying the operating manual. Agreement between all examiners was acceptable to excellent (intraclass coefficient > 0.4). The mean value of the measured differences for the central incisors of all subjects for L* values was 5 (for C* = 3.8, h* = 2.7 degrees) and for canines, the mean L* was 4.5 (C* = 3, h* = 1.6 degrees). Results from comparison of the 2 different training methods were inconsistent. Agreement with the experienced examiner ranged from not acceptable (C* values for incisors of self-instructed examiners) to excellent. The distribution of the measurements of 1 subject could lead to deviations in color, probably with clinical impact. For canines, the measurements were at least equally reproducible (in some cases significantly more reproducible) compared to central incisors. Because of the small number of examiners and the inconsistent results, it was not possible to reach a definite conclusion about the effect of different training methods on interexaminer reliability.

  20. Logic Estimation of the Optimum Source Neutron Energy for BNCT of Brain Tumors

    International Nuclear Information System (INIS)

    Dorrah, M.A.; Gaber, F.A.; Abd Elwahab, M.A.; Kotb, M.A.; Mohammed, M.M.

    2012-01-01

    BNCT is very complicated technique; primarily due to the complexity of element composition of the brain. Moreover; numerous components contributes to the over all radiation dose both to normal brain and to tumor. Simple algebraic summation cannot be applied to these dose components, since each component should at first be weighed by its relative biological effectiveness (RBE) value. Unfortunately, there is no worldwide agreement on these RBE values. For that reason, the parameters required for accurate planning of BNCT of brain tumors located at different depths in brain remained obscure. The most important of these parameters is; the source neutron energy. Thermal neutrons were formerly employed for BNCT, but they failed to prove therapeutic efficacy. Later on; epithermal neutrons were suggested proposing that they would be enough thermalized while transporting in the brain tissues. However; debate aroused regarding the source neutrons energy appropriate for treating brain tumors located at different depths in brain. Again, the insufficient knowledge regarding the RBE values of the different dose components was a major obstacle. A new concept was adopted for estimating the optimum source neutrons energy appropriate for different circumstances of BNCT. Four postulations on the optimum source neutrons energy were worked out, almost entirely independent of the RBE values of the different dose components. Four corresponding condition on the optimum source neutrons energy were deduced. An energy escalation study was carried out investigating 65 different source neutron energies, between 0.01 eV and 13.2 MeV. MCNP4B Monte C arlo neutron transport code was utilized to study the behavior of neutrons in the brain. The deduced four conditions were applied to the results of the 65 steps of the neutron energy escalation study. A source neutron energy range of few electron volts (eV) to about 30 keV was estimated to be the most appropriate for BNCT of brain tumors located at

  1. The clinical value of CT in neuropediatrics

    International Nuclear Information System (INIS)

    Reisner, Th.

    1981-01-01

    Cranial computed-tomography (CT) has opened new dimensions in neuropediatric diagnosis. The relationship between clinical symptoms and CT results is presented. 1930 patients were investigated, one group is made up of 334 newborns and infants, the other group contains children in the age between 13 months and 15 years. Newborns and infants confront the neurologist with stereotyped deficiency symptoms which nevertheless can arise from many causes. CT can make an etiological classification. In childhood illnesses of neurophsychiatric nature sometimes predominate whose clinical symptoms are often minimal (e.g. cerebral seizures, hydrocephalus, perinatal brain damage, various types of headache etc.). Here again CT can give the clinical valuable indications concerning diagnosis and therapeutic procedure. (M.J.)

  2. Proton Arc Reduces Range Uncertainty Effects and Improves Conformality Compared With Photon Volumetric Modulated Arc Therapy in Stereotactic Body Radiation Therapy for Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Seco, Joao, E-mail: jseco@partners.org [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Gu, Guan; Marcelos, Tiago; Kooy, Hanne; Willers, Henning [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2013-09-01

    Purpose: To describe, in a setting of non-small cell lung cancer (NSCLC), the theoretical dosimetric advantages of proton arc stereotactic body radiation therapy (SBRT) in which the beam penumbra of a rotating beam is used to reduce the impact of range uncertainties. Methods and Materials: Thirteen patients with early-stage NSCLC treated with proton SBRT underwent repeat planning with photon volumetric modulated arc therapy (Photon-VMAT) and an in-house-developed arc planning approach for both proton passive scattering (Passive-Arc) and intensity modulated proton therapy (IMPT-Arc). An arc was mimicked with a series of beams placed at 10° increments. Tumor and organ at risk doses were compared in the context of high- and low-dose regions, represented by volumes receiving >50% and <50% of the prescription dose, respectively. Results: In the high-dose region, conformality index values are 2.56, 1.91, 1.31, and 1.74, and homogeneity index values are 1.29, 1.22, 1.52, and 1.18, respectively, for 3 proton passive scattered beams, Passive-Arc, IMPT-Arc, and Photon-VMAT. Therefore, proton arc leads to a 30% reduction in the 95% isodose line volume to 3-beam proton plan, sparing surrounding organs, such as lung and chest wall. For chest wall, V30 is reduced from 21 cm{sup 3} (3 proton beams) to 11.5 cm{sup 3}, 12.9 cm{sup 3}, and 8.63 cm{sup 3} (P=.005) for Passive-Arc, IMPT-Arc, and Photon-VMAT, respectively. In the low-dose region, the mean lung dose and V20 of the ipsilateral lung are 5.01 Gy(relative biological effectiveness [RBE]), 4.38 Gy(RBE), 4.91 Gy(RBE), and 5.99 Gy(RBE) and 9.5%, 7.5%, 9.0%, and 10.0%, respectively, for 3-beam, Passive-Arc, IMPT-Arc, and Photon-VMAT, respectively. Conclusions: Stereotactic body radiation therapy with proton arc and Photon-VMAT generate significantly more conformal high-dose volumes than standard proton SBRT, without loss of coverage of the tumor and with significant sparing of nearby organs, such as chest wall. In addition

  3. Relative Biological Effectiveness of HZE Fe Ions for Induction ofMicro-Nuclei at Low Doses

    Energy Technology Data Exchange (ETDEWEB)

    Groesser, Torsten; Chun, Eugene; Rydberg, Bjorn

    2007-01-16

    Dose-response curves for induction of micro-nuclei (MN) was measured in Chinese hamster V79 and xrs6 (Ku80-) cells and in human mammary epithelial MCF10A cells in the dose range of 0.05-1 Gy. The Chinese Hamster cells were exposed to 1 GeV/u Fe ions, 600 MeV/u Fe ions, and 300 MeV/u Fe ions (LETs of 151, 176 and 235 keV/{micro}m respectively) as well as with 320 kVp X-rays as reference. Second-order polynomials were fitted to the induction curves and the initial slopes (the alpha values) were used to calculate RBE. For the repair proficient V79 cells the RBE at these low doses increased with LET. The values obtained were 3.1 (LET=151 keV/{micro}m), 4.3 (LET = 176 keV/{micro}m) and 5.7 (LET = 235 keV/{micro}m), while the RBE was close to 1 for the repair deficient xrs6 cells regardless of LET. For the MCF10A cells the RBE was determined for 1 GeV/u Fe ions and found to be 5.4, slightly higher than for V79 cells. To test the effect of shielding, the 1 GeV/u Fe ion beam was intercepted by various thickness of high-density polyethylene plastic absorbers, which resulted in energy loss and fragmentation. It was found that the MN yield for V79 cells placed behind the absorbers decreased in proportion to the decrease in dose both before and after the Fe ion Bragg peak (excluding the area around the Fe-ion Bragg peak itself), indicating that RBE did not change significantly due to shielding. At the Bragg peak the effectiveness for MN formation per unit dose was decreased, indicating an 'overkill' effect by low-energy very high-LET Fe ions.

  4. Unilateral irradiation of pigs in a mixed neutrons+gamma field. Early results

    International Nuclear Information System (INIS)

    Lemaitre, Guy; Maas, Jean.

    1982-08-01

    Pigs (16-20kg) were irradiated with 60 Co gamma or in a mixed field (neutron + gamma from the pulsed reactor SILENE). Pigs were unilaterally exposed by the left side. Each experimental group was composed of twelve animals and one control. Within the dose range explored (reference dose is mid-line tissue dose): 4-9.8 Gy of gamma rays only; 4.6 - 5.7 Gy of neutrons and gamma rays, pigs presented the haematopioetic form of the acute radiation sickness. At 5 Gy mixed field was more harmful than gamma rays only. Therefore the numerical value of neutron RBE (lethality 50 p cent within 30 days) is more than one. Experiments will be carried out in order to determine RBE values more accurately. Bone marrow dose will also be determined [fr

  5. The role and clinical value of thallium-201 myocardial scintigraphy in ischemic heart disease

    International Nuclear Information System (INIS)

    Shimada, Tomoyoshi; Nakamori, Hisato; Kurimoto, Toru; Karakawa, Masahiro; Matsuura, Takashi; Iwasaka, Toshiji; Inada, Mitsuo; Nishiyama, Yutaka

    1990-01-01

    To define the role and clinical value of thallium-201 myocardial scintigraphy in ischemic heart disease, 967 consecutive patients refered to our laboratory since 1985 were studied. The purpose of scintigraphy have changed from diagnosing of myocardial ischemia to assessing myocardial viability with the progress of coronary angioplasty. At present, thallium-201 myocardial scintigraphy have become indispensable noninvasive method for the management of patients with ischemic heart disease. (author)

  6. Evolving role of hadron irradiation: Potential and risks of hadrons heavier than protons

    International Nuclear Information System (INIS)

    Levy, Richard P.

    2007-01-01

    Proton irradiation has been developed to achieve the clinical benefit of improved 3D-dose distribution, with biological properties similar to X-rays. Neutron irradiation, though much less 3D-conformal than proton treatment, has been developed to take advantage of increased relative biologic effectiveness (RBE). Irradiation with hadrons heavier than protons (e.g. carbon and neon ions) exhibits the unique combination of improved 3D-dose distribution and increased RBE. The synchrotron technology is rapidly developing to improve the efficiency of delivering these heavier hadrons clinically, but important issues remain regarding optimization of dose and fractionation parameters in the treatment of various histopathologies located in different portions of the anatomy. Many laboratory animal and in vitro cellular studies, and some clinical studies, have been performed to enable better understanding of how to adjust dose-fractionation selection to improve the therapeutic ratio of tumor-cell kill to normal-tissue injury. This paper highlights the enhanced therapeutic potential and associated risks of treatment with these heavier hadrons

  7. Identification and functional analysis of a second RBF-2 binding site within the HIV-1 promoter

    International Nuclear Information System (INIS)

    Dahabieh, Matthew S.; Ooms, Marcel; Malcolm, Tom; Simon, Viviana; Sadowski, Ivan

    2011-01-01

    Transcription from the HIV-1 long terminal repeat (LTR) is mediated by numerous host transcription factors. In this study we characterized an E-box motif (RBE1) within the core promoter that was previously implicated in both transcriptional activation and repression. We show that RBE1 is a binding site for the RBF-2 transcription factor complex (USF1, USF2, and TFII-I), previously shown to bind an upstream viral element, RBE3. The RBE1 and RBE3 elements formed complexes of identical mobility and protein constituents in gel shift assays, both with Jurkat T-cell nuclear extracts and recombinant USF/TFII-I. Furthermore, both elements are regulators of HIV-1 expression; mutations in LTR-luciferase reporters and in HIV-1 molecular clones resulted in decreased transcription, virion production, and proviral expression in infected cells. Collectively, our data indicate that RBE1 is a bona fide RBF-2 binding site and that the RBE1 and RBE3 elements are necessary for mediating proper transcription from the HIV-1 LTR.

  8. The clinical value of routine whole-body magnetic resonance imaging (MRI) in palliative care

    Energy Technology Data Exchange (ETDEWEB)

    Geitung, Jonn Terje (Department of Radiology, Haraldspass Deaconess (University) Hospital (Norway); Department of Surgical Sciences, University of Bergen (Norway)), Email: jtgeit@online.no; Eikeland, Joakim (Department of Public Health and Primary Health Care, University of Bergen (Norway)); Rosland, Jan Henrik (Department of Public Health and Primary Health Care, University of Bergen (Norway); Sunniva Clinic for Palliative Care, Haraldsplass Deaconess (University) Hospital (Norway))

    2012-03-15

    Background. Whole-body MRI (WBMRI) has become an accessible method for detecting different types of pathologies both in the skeleton and the viscera, which may explain painful conditions, for example tumors and inflammation. Purpose. To assess a possible value of using WBMRI in order to improve palliative care. Material and Methods. Twenty patients (all eligible patients) admitted to the Department for Palliative Care were consecutively included in this study. They underwent a modified WBMRI, with fewer and shorter pulse sequences than in a standard WBMRI, to reduce patient stress. However, the patients' physicians were to exclude patients where little might be obtained and discomfort, distress, and pain could be induced. The treating physicians registered clinical utility directly after receiving the MRI report in a questionnaire. The registration was repeated after ended treatment. Results. Eighty percent had new findings detected, and 40% of the patients had a change in treatment due to the MRI result, mainly changes in analgesics and/or radiation therapy. Conclusion. The WBMRI helped the clinicians to improve treatment and a majority of the patients benefited from this. In eight patients the treatment was changed due to the results. The clinical value (utility) was indicated to be high

  9. R.b.e. of 50 kVp X-rays and 660 keV γ-rays (137Cs) with respect to the production of DNA damage, repair and cell-killing in Escherichia coli K-12

    International Nuclear Information System (INIS)

    Bonura, T.; Youngs, D.A.; Smith, K.C.

    1975-01-01

    A comparison has been made of the efficiency of cell-killing, DNA single-strand breakage and double-strand breakage in an Escherichia coli K-12 wild-type strain after irradiation with soft X-rays (50 kVp) and hard γ-rays (660 keV) under aerobic conditions. Irradiation with 50 kVp X-rays resulted in 1.47 times more cell-killing than was observed with 137 Cs γ-rays based on a comparison of D 0 values evaluated from the survival curves. DNA sedimentation studies showed that, although 50 kVp X-rays were 1.93 times more effective than 137 Cs γ-rays in producing DNA double-strand breaks, there was no significant difference between the two qualities of radiation with respect to the initial number of single-strand breaks produced. When the cells were irradiated and allowed to repair maximally in minimal medium, 1.57 times more unrepaired DNA single-strand breaks remained per krad after irradiation with 50 kVp X-rays than with 137 Cs γ-rays. The increased yield of DNA double-strand breaks resulting from 50 kVp X-irradiation may account for most of these additional unrepaired single-strand breaks, since single- and double-strand breaks are indistinguishable on alkaline sucrose gradients. These results suggest that the greater r.b.e. of 50 kVp X-rays may be related to an increased effectiveness for producing DNA double-strand breaks compared with the higher energy 137 Cs γ-rays. (author)

  10. SU-F-T-196: Hypo-Fractionation with Intensity Modulated Proton Therapy for Unilateral Metallic Prosthesis Prostate Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Rana, S; Park, S [McLaren Proton Therapy Center, Karmanos Cancer Institute at McLaren-Flint, Flint, MI (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States); Zhang, Y [University of Cincinnati Medical Center, Liberty Township, OH (United States); Pokharel [21st Century Oncology, Estero, FL (United States); Cheng, C [Vantage Oncology, West Hills, CA (United States)

    2016-06-15

    Purpose: The purpose of this study is to investigate the dosimetric feasibility of hypo-fractionated intensity modulated proton therapy (IMPT) for unilateral metallic prosthesis prostate cancer patients based on proton collaborative group (PCG)-GU002-10 (NCT01230866) protocol criteria. Methods: A total of five unilateral metallic prosthesis prostate cancer cases were included in this retrospective study. For each case, IMPT plans were generated for treatment to be delivered with 7.6 Gy[RBE] per fraction in 5 fractions per week for a total dose of 38 Gy(RBE). Each plan was generated using two anterior-oblique beams and one lateral beam. Treatment plans were optimized with an objective meeting PCG-GU002-10 (NCT01230866) protocol criteria: (i) planning target volume (PTV): D99.5% > 36.1 Gy[RBE], (ii) rectum: V24 < 35%, V33.6 < 10%, (iii) bladder: V39 < 8 cc, and (iv) femoral head: V23 < 1cc. Results: All five cases satisfied PTV D99.5% (average=36.82 Gy[RBE]; range, 36.36–37.13 Gy[RBE]). PTV D95% ranged from 36.66 Gy[RBE] to 38.65 Gy[RBE] and PTV V100 ranged from 95.47% to 97.95%. For the rectum, V24 was less than 35% (average=14.07 Gy[RBE]; range, 6.22–18.42%, whereas V33.6 Gy[RBE] was less than 10% (average=6.83; range, 3.06 – 9.15%). Rectal mean dose ranged from 4.22 Gy[RBE] to 9.97 Gy[RBE]. For the bladder, V39 was found to be less than 8 cc (average=3.69 cc; range, 0.19–7.68 cc). Bladder mean dose ranged from 4.22 Gy[RBE] to 18.83 Gy[RBE]. For the femoral head, V23 was 0 in all five cases. Conclusion: All five unilateral metallic prosthesis prostate cancer IMPT plans generated with one lateral and two anterior-oblique beams satisfied the dosimetric criteria of PCG-GU002-10 (NCT01230866) protocol.

  11. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

    International Nuclear Information System (INIS)

    Johnson, J.R.; Myers, D.K.; Jackson, J.S.; Dunford, D.W.; Gragtmans, N.J.; Wyatt, H.M.; Jones, A.R.; Percy, D.H.

    1995-01-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium β rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium 13 rays compared to X rays ranged from 1.0 ± 0.5 to 1.3 ± 0.3. A best estimate of the RBE for this experiment was about 1.2 ± 0.3. A w R value of 1 would thus appear to be more appropriate than a W R of 2 for tritium β rays. (author)

  12. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.R. [Battelle Pacific Northwest Labs., Health Protection Branch, Health Div., Richland, WA (United States); Myers, D.K.; Jackson, J.S.; Dunford, D.W.; Gragtmans, N.J.; Wyatt, H.M.; Jones, A.R. [Atomic Energy of Canada Limited, Chalk River, Ontairo (Canada); Percy, D.H. [Univ. of Guelph, Ontario Veterinary College, Guelph, Ontario (Canada)

    1995-07-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium {beta} rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium 13 rays compared to X rays ranged from 1.0 {+-} 0.5 to 1.3 {+-} 0.3. A best estimate of the RBE for this experiment was about 1.2 {+-} 0.3. A w{sub R} value of 1 would thus appear to be more appropriate than a W{sub R} of 2 for tritium {beta} rays. (author)

  13. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice.

    Science.gov (United States)

    Johnson, J R; Myers, D K; Jackson, J S; Dunford, D W; Gragtmans, N J; Wyatt, H M; Jones, A R; Percy, D H

    1995-10-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.

  14. Clinical value of prognosis gene expression signatures in colorectal cancer: a systematic review.

    Directory of Open Access Journals (Sweden)

    Rebeca Sanz-Pamplona

    Full Text Available INTRODUCTION: The traditional staging system is inadequate to identify those patients with stage II colorectal cancer (CRC at high risk of recurrence or with stage III CRC at low risk. A number of gene expression signatures to predict CRC prognosis have been proposed, but none is routinely used in the clinic. The aim of this work was to assess the prediction ability and potential clinical usefulness of these signatures in a series of independent datasets. METHODS: A literature review identified 31 gene expression signatures that used gene expression data to predict prognosis in CRC tissue. The search was based on the PubMed database and was restricted to papers published from January 2004 to December 2011. Eleven CRC gene expression datasets with outcome information were identified and downloaded from public repositories. Random Forest classifier was used to build predictors from the gene lists. Matthews correlation coefficient was chosen as a measure of classification accuracy and its associated p-value was used to assess association with prognosis. For clinical usefulness evaluation, positive and negative post-tests probabilities were computed in stage II and III samples. RESULTS: Five gene signatures showed significant association with prognosis and provided reasonable prediction accuracy in their own training datasets. Nevertheless, all signatures showed low reproducibility in independent data. Stratified analyses by stage or microsatellite instability status showed significant association but limited discrimination ability, especially in stage II tumors. From a clinical perspective, the most predictive signatures showed a minor but significant improvement over the classical staging system. CONCLUSIONS: The published signatures show low prediction accuracy but moderate clinical usefulness. Although gene expression data may inform prognosis, better strategies for signature validation are needed to encourage their widespread use in the clinic.

  15. A Prospective Comparison of the Effects of Interfractional Variations on Proton Therapy and Intensity Modulated Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Moteabbed, Maryam, E-mail: mmoteabbed@partners.org; Trofimov, Alexei; Sharp, Gregory C.; Wang, Yi; Zietman, Anthony L.; Efstathiou, Jason A.; Lu, Hsiao-Ming

    2016-05-01

    Purpose: To quantify and compare the impact of interfractional setup and anatomic variations on proton therapy (PT) and intensity modulated radiation therapy (IMRT) for prostate cancer. Methods and Materials: Twenty patients with low-risk or intermediate-risk prostate cancer randomized to receive passive-scattering PT (n=10) and IMRT (n=10) were selected. For both modalities, clinical treatment plans included 50.4 Gy(RBE) to prostate and proximal seminal vesicles, and prostate-only boost to 79.2 Gy(RBE) in 1.8 Gy(RBE) per fraction. Implanted fiducials were used for prostate localization and endorectal balloons were used for immobilization. Patients in PT and IMRT arms received weekly computed tomography (CT) and cone beam CT (CBCT) scans, respectively. The planned dose was recalculated on each weekly image, scaled, and mapped onto the planning CT using deformable registration. The resulting accumulated dose distribution over the entire treatment course was compared with the planned dose using dose-volume histogram (DVH) and γ analysis. Results: The target conformity index remained acceptable after accumulation. The largest decrease in the average prostate D{sub 98} was 2.2 and 0.7 Gy for PT and IMRT, respectively. On average, the mean dose to bladder increased by 3.26 ± 7.51 Gy and 1.97 ± 6.84 Gy for PT and IMRT, respectively. These values were 0.74 ± 2.37 and 0.56 ± 1.90 for rectum. Differences between changes in DVH indices were not statistically significant between modalities. All volume indices remained within the protocol tolerances after accumulation. The average pass rate for the γ analysis, assuming tolerances of 3 mm and 3%, for clinical target volume, bladder, rectum, and whole patient for PT/IMRT were 100/100, 92.6/99, 99.2/100, and 97.2/99.4, respectively. Conclusion: The differences in target coverage and organs at risk dose deviations for PT and IMRT were not statistically significant under the guidelines of this protocol.

  16. ERP in chronic pancreatitis - ductal morphology, relation to exocrine function and pain - clinical value

    International Nuclear Information System (INIS)

    Norup Lauridsen, K.; Raahede, J.; Kruse, A.; Thommesen, P.; Aarhus Univ.

    1985-01-01

    ERP was analyzed in 87 patients with chronic pancreatitis with special reference to its clinical value in management of pain, the dominating symptom in uncomplicated chronic pancreatitis. A significant correlation was found between ductal changes due to pancreatitis and decrease in pancreatic function. However, no association was found between severe pancreatic pain and pancreatic function or pancreatic morphology. The significance of ERP in management of patients with persistent severe pancreatic pain is discussed. (orig.) [de

  17. Clinical value of serum vitamin B12 and folate in cerebrovascular disease

    International Nuclear Information System (INIS)

    Zhan Hao; Zhang Yongxue

    2002-01-01

    To study the clinical value of serum vitamin B 12 and folate in cerebrovascular disease, the concentration of serum vitamin B 12 and folate in 32 patients with cerebrovascular disease was measured by radioimmunoassay. The results showed that the changes in folate in all groups were not significant. The content of vitamin B 12 in multi-infarct dementia was markedly lower than that in cerebral infarction and cerebral hemorrhage. Moreover, the level of vitamin B 12 was lower in paralytic patients with muscular strength of grade 0-III. It can be concluded that serum vitamin B 12 level had association with intelligent disorder and paralytic degree

  18. Value of FFR in clinical practice

    Directory of Open Access Journals (Sweden)

    Anil Mehra

    2015-01-01

    Full Text Available Fractional flow reserve is an important tool in the cardiac catheterization lab to assess the physiological significance of coronary lesions. This article discusses the basic concepts about FFR and its utility in clinical decision making.

  19. DNA double-strand breaks induced by high-energy neon and iron ions in human fibroblasts. I. Pulsed-field gel electrophoresis method

    International Nuclear Information System (INIS)

    Rydberg, B.; Loebrich, M.; Cooper, P.K.

    1994-01-01

    The relative effectiveness of high-energy neon and iron ions for the production of DNA double-strand breaks was measured in one transformed and one nontransformed human fibroblast cell line using pulsed-field gel electrophoresis. The DNA released from the gel plug (fraction of activity released: FAR) as well as the size distribution of the DNA entering the gel were used to compare the effects of the heavy-ion exposure with X-ray exposure. Both methods gave similar results, indicating similar distributions of breaks over megabase-pair distances for the heavy ions and the X rays. The relative biological effectiveness (RBE) compared to 225 kVp X rays of initially induced DNA double-strand breaks was found to be 0.85 for 425 MeV/u neon ions (LET 32 keV/μm) and 0.42-0.55 for 250-600 MeV/u iron ions (LET 190-350 keV/μm). Postirradiation incubation showed less efficient repair of breaks induced by the neon ions and the 600 MeV/u iron ions compared to X rays. Survival experiments demonstrated RBE values larger than one for cell killing by the heavy ions in parallel experiments (neon: RBE = 1.2, iron: RBE = 2.3-3.0, based on D 10 values). It is concluded that either the initial yield of DNA double-strand breaks induced by the high-energy particles is lower than the yield for X rays, or the breaks induced by heavy ions are present in clusters that cannot be resolved with the technique used. These results are confirmed in the accompanying paper. 48 refs., 5 figs., 2 tabs

  20. Health-related physical fitness measures: reference values and reference equations for use in clinical practice.

    Science.gov (United States)

    Tveter, Anne Therese; Dagfinrud, Hanne; Moseng, Tuva; Holm, Inger

    2014-07-01

    To provide reference values and reference equations for frequently used clinical field tests of health-related physical fitness for use in clinical practice. Cross-sectional design. General community. Convenience sample of volunteers (N=370) between 18 and 90 years of age were recruited from a wide range of settings (ie, work sites, schools, community centers for older adults) and different geographic locations (ie, urban, suburban, rural) in southeastern Norway. Not applicable. The participants conducted 5 clinical field tests (6-minute walk test, stair test, 30-second sit-to-stand test, handgrip test, fingertip-to-floor test). The results of the field tests showed that performance remained unchanged until approximately 50 years of age; after that, performance deteriorated with increasing age. Grip strength (79%), meters walked in 6 minutes (60%), and seconds used on the stair test (59%) could be well predicted by age, sex, height, and weight in participants ≥50 years of age, whereas the performance on all tests was less well predicted in participants clinical practice. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  1. [Value of nutritional risk screening in evaluating adverse clinical outcomes in children with severe pneumonia].

    Science.gov (United States)

    Guo, Xiao-Hui; Sun, Yan-Feng; Wang, Jiang-Bo; Han, Shu-Zhen; Miao, Jing; Cui, Min

    2017-03-01

    To investigate the nutritional risk in children with severe pneumonia using the Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP) and the association between nutritional risk and adverse clinical outcomes. According to the STAMP score, 216 children with severe pneumonia were classified into high nutritional risk group (HR group; n=98), moderate nutritional risk group (MR group; n=65), and low nutritional risk group (LR group; n=53). Fasting blood samples were collected to measure the levels of insulin-like growth factor-1 (IGF-1), adiponectin, leptin, non-esterified fatty acid (NEFA), albumin, transferrin, prealbumin, and retinol binding protein (RBP). The adverse clinical outcomes were recorded. Compared with the MR and LR groups, the HR group had significantly lower serum levels of IGF-1, leptin, adiponectin, prealbumin, and RBP, as well as a significantly higher serum level of NEFA (Prisk screening has an important value in evaluating the clinical outcome of children with severe pneumonia, and children at a higher nutritional risk tend to have more adverse clinical outcomes.

  2. The value of pathogen information in treating clinical mastitis.

    Science.gov (United States)

    Cha, Elva; Smith, Rebecca L; Kristensen, Anders R; Hertl, Julia A; Schukken, Ynte H; Tauer, Loren W; Welcome, Frank L; Gröhn, Yrjö T

    2016-11-01

    The objective of this study was to determine the economic value of obtaining timely and more accurate clinical mastitis (CM) test results for optimal treatment of cows. Typically CM is first identified when the farmer observes recognisable outward signs. Further information of whether the pathogen causing CM is Gram-positive, Gram-negative or other (including no growth) can be determined by using on-farm culture methods. The most detailed level of information for mastitis diagnostics is obtainable by sending milk samples for culture to an external laboratory. Knowing the exact pathogen permits the treatment method to be specifically targeted to the causation pathogen, resulting in less discarded milk. The disadvantages are the additional waiting time to receive test results, which delays treating cows, and the cost of the culture test. Net returns per year (NR) for various levels of information were estimated using a dynamic programming model. The Value of Information (VOI) was then calculated as the difference in NR using a specific level of information as compared to more detailed information on the CM causative agent. The highest VOI was observed where the farmer assumed the pathogen causing CM was the one with the highest incidence in the herd and no pathogen specific CM information was obtained. The VOI of pathogen specific information, compared with non-optimal treatment of Staphylococcus aureus where recurrence and spread occurred due to lack of treatment efficacy, was $20.43 when the same incorrect treatment was applied to recurrent cases, and $30.52 when recurrent cases were assumed to be the next highest incidence pathogen and treated accordingly. This indicates that negative consequences associated with choosing the wrong CM treatment can make additional information cost-effective if pathogen identification is assessed at the generic information level and if the pathogen can spread to other cows if not treated appropriately.

  3. Effect of neutrons with an energy of 0.35 and 0.85 MeV and gamma radiation of 60Co on the organ cultures of the human bone marrow

    International Nuclear Information System (INIS)

    Zherbin, E.A.; Kolesnikova, A.I.; Konoplyannikov, A.G.; Khoptynskaya, S.K.; Obaturov, G.M.; Kapchigashev, S.P.

    1979-01-01

    A comparative study of the radiation injury of human hemopoietic cells under the effect of γ radiation of 60 Co in doses from 100 to 1500 rad, 0.85 MeV neutrons in doses from 50 to 600 rad and 0.35 MeV neutrons in doses from 30 to 600 rad was carried out using the method of organic cultivation of bone marrow. Under the effect of the above radiation types, the fissionable granulocytes (promyelocytes and myelocytes) and lymphocytes are most radiosensitive among the 4-day organic cultures. The dose dependence of the decrease in relative and absolute content of these cell forms in the cultures as well as the dose dependence of the decrease in total cell structure in the cultures were revealed. It has been found that the dose dependence for the above tests consists of two components: radiosensitive and radioresistant ones. The radiation doses causing death in 50% of cells in relation to control (D 50 ) were determined. On the bases of D 50 values, the coefficients of relative biological efficiency (RBE) were calculated for 0.85 and 0.35 MeV neutrons. The RBE coefficients are confined in the 1.4-3.4 and 2.4-6.7 intervals respectively. It has been confirmed that 0.35 MeV neutrons are 1.5-2 times more effective than 0.85 MeV neutrons. The coefficients of RBE neutrons calculated for radioresistant cell components are higher than the corresponding values estimated according to D 50 value; in some cases they reach values ranging from 6 to 10

  4. Value 101: the basics of clinical transformation.

    Science.gov (United States)

    Hancock, Melinda S

    2013-06-01

    Health systems should take strong steps to ensure that their current and aspiring finance leaders are fully prepared to engage with clinicians in meeting the requirements of healthcare reform. In 2012, Bon Secours held a clinical transformation finance intensive to teach finance staff how to accelerate clinical transformation within their markets. The education and skills that Bon Secours' finance professionals gained from the intensive have strengthened the health system's ability to respond to the challenges of reform.

  5. Clinical value of the Ottawa ankle rules for diagnosis of fractures in acute ankle injuries.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    Full Text Available BACKGROUND: The Ottawa ankle rules (OAR are clinical decision guidelines used to identify whether patients with ankle injuries need to undergo radiography. The OAR have been proven that their application reduces unnecessary radiography. They have nearly perfect sensitivity for identifying clinically significant ankle fractures. OBJECTIVES: The purpose of this study was to assess the applicability of the OAR in China, to examine their accuracy for the diagnosis of fractures in patients with acute ankle sprains, and to assess their clinical utility for the detection of occult fractures. METHODS: In this prospective study, patients with acute ankle injuries were enrolled during a 6-month period. The eligible patients were examined by emergency orthopedic specialists using the OAR, and then underwent ankle radiography. The results of examination using the OAR were compared with the radiographic results to assess the accuracy of the OAR for ankle fractures. Patients with OAR results highly suggestive of fracture, but no evidence of a fracture on radiographs, were advised to undergo 3-dimensional computed tomography (3D-CT. RESULTS: 183 patients with ankle injuries were enrolled in the study and 63 of these injuries involved fractures. The pooled sensitivity, specificity, positive predictive value and negative predictive value of the OAR for detection of fractures of the ankle were 96.8%, 45.8%, 48.4% and 96.5%, respectively. Our results suggest that clinical application of the OAR could decrease unnecessary radiographs by 31.1%. Of the 21 patients with positive OAR results and negative radiographic findings who underwent 3D-CT examination, five had occult fractures of the lateral malleolus. CONCLUSIONS: The OAR are applicable in the Chinese population, and have high sensitivity and modest specificity for the diagnosis of fractures associated with acute ankle injury. They may detect some occult fractures of the malleoli that are not visible on

  6. Service quality and perceived value of technology-based service encounters: evaluation of clinical staff satisfaction in Taiwan.

    Science.gov (United States)

    Hung, Chung-Jye; Chang, Hsin Hsin; Eng, Cheng Joo; Wong, Kit Hong

    Previous research has evaluated technology-based service encounters (TBSEs) in the delivery of health care by assessing patient satisfaction. This study examined service quality and perceived value of TBSEs used in health organisations from the perspective of clinical staff, with staff technology readiness as a moderator. A quantitative survey was conducted in Taiwan, across private and public healthcare organisations. Results showed that TBSEs had a direct effect on service quality and perceived value, which in turn had a direct effect on staff satisfaction in using TBSEs. However, service quality had no effect on perceived value when moderated by technology readiness. Theoretical and managerial implications of these findings are discussed.

  7. ProvenCare: Geisinger's Model for Care Transformation through Innovative Clinical Initiatives and Value Creation.

    Science.gov (United States)

    2009-04-01

    Geisinger's system of care can be seen as a microcosm of the national delivery of healthcare, with implications for decision makers in other health plans. In this interview, Dr Ronald A. Paulus focuses on Geisinger's unique approach to patient care. In its core, this approach represents a system of quality and value initiatives based on 3 major programs-Proven Health Navigation (medical home); the ProvenCare model; and transitions of care. The goal of such an approach is to optimize disease management by using a rational reimbursement paradigm for appropriate interventions, providing innovative incentives, and engaging patients in their own care as part of any intervention. Dr Paulus explains the reasons why, unlike Geisinger, other stakeholders, including payers, providers, patients, and employers, have no intrinsic reasons to be concerned with quality and value initiatives. In addition, he says, an electronic infrastructure that could be modified as management paradigms evolve is a necessary tool to ensure the healthcare delivery system's ability to adapt to new clinical realities quickly to ensure the continuation of delivering best value for all stakeholders.

  8. Analyzing patients' values by applying cluster analysis and LRFM model in a pediatric dental clinic in Taiwan.

    Science.gov (United States)

    Wu, Hsin-Hung; Lin, Shih-Yen; Liu, Chih-Wei

    2014-01-01

    This study combines cluster analysis and LRFM (length, recency, frequency, and monetary) model in a pediatric dental clinic in Taiwan to analyze patients' values. A two-stage approach by self-organizing maps and K-means method is applied to segment 1,462 patients into twelve clusters. The average values of L, R, and F excluding monetary covered by national health insurance program are computed for each cluster. In addition, customer value matrix is used to analyze customer values of twelve clusters in terms of frequency and monetary. Customer relationship matrix considering length and recency is also applied to classify different types of customers from these twelve clusters. The results show that three clusters can be classified into loyal patients with L, R, and F values greater than the respective average L, R, and F values, while three clusters can be viewed as lost patients without any variable above the average values of L, R, and F. When different types of patients are identified, marketing strategies can be designed to meet different patients' needs.

  9. Analyzing Patients' Values by Applying Cluster Analysis and LRFM Model in a Pediatric Dental Clinic in Taiwan

    Science.gov (United States)

    Lin, Shih-Yen; Liu, Chih-Wei

    2014-01-01

    This study combines cluster analysis and LRFM (length, recency, frequency, and monetary) model in a pediatric dental clinic in Taiwan to analyze patients' values. A two-stage approach by self-organizing maps and K-means method is applied to segment 1,462 patients into twelve clusters. The average values of L, R, and F excluding monetary covered by national health insurance program are computed for each cluster. In addition, customer value matrix is used to analyze customer values of twelve clusters in terms of frequency and monetary. Customer relationship matrix considering length and recency is also applied to classify different types of customers from these twelve clusters. The results show that three clusters can be classified into loyal patients with L, R, and F values greater than the respective average L, R, and F values, while three clusters can be viewed as lost patients without any variable above the average values of L, R, and F. When different types of patients are identified, marketing strategies can be designed to meet different patients' needs. PMID:25045741

  10. Analyzing Patients’ Values by Applying Cluster Analysis and LRFM Model in a Pediatric Dental Clinic in Taiwan

    Directory of Open Access Journals (Sweden)

    Hsin-Hung Wu

    2014-01-01

    Full Text Available This study combines cluster analysis and LRFM (length, recency, frequency, and monetary model in a pediatric dental clinic in Taiwan to analyze patients’ values. A two-stage approach by self-organizing maps and K-means method is applied to segment 1,462 patients into twelve clusters. The average values of L, R, and F excluding monetary covered by national health insurance program are computed for each cluster. In addition, customer value matrix is used to analyze customer values of twelve clusters in terms of frequency and monetary. Customer relationship matrix considering length and recency is also applied to classify different types of customers from these twelve clusters. The results show that three clusters can be classified into loyal patients with L, R, and F values greater than the respective average L, R, and F values, while three clusters can be viewed as lost patients without any variable above the average values of L, R, and F. When different types of patients are identified, marketing strategies can be designed to meet different patients’ needs.

  11. SU-F-T-189: Dosimetric Comparison of Spot-Scanning Proton Therapy Techniques for Liver Tumors Close to the Skin Surface

    International Nuclear Information System (INIS)

    Takao, S; Matsuzaki, Y; Matsuura, T; Umegaki, K; Fujii, Y; Fujii, T; Katoh, N; Shimizu, S; Shirato, H

    2016-01-01

    Purpose: Spot-scanning technique has been utilized to achieve conformal dose distribution to large and complicated tumors. This technique generally does not require patient-specific devices such as aperture and compensator. The commercially available spot-scanning proton therapy (SSPT) systems, however, cannot deliver proton beams to the region shallower than 4 g/cm2. Therefore some range compensation device is required to treat superficial tumors with SSPT. This study shows dosimetric comparison of the following treatment techniques: (i) with a tabletop bolus, (ii) with a nozzle-mounted applicator, and (iii) without any devices and using intensity-modulated proton therapy (IMPT) technique. Methods: The applicator composed of a combination of a mini-ridge filter and a range shifter has been manufactured by Hitachi, Ltd., and the tabletop bolus was made by .decimal, Inc. Both devices have been clinically implemented in our facility. Three patients with liver tumors close to the skin surface were examined in this study. Each treatment plan was optimized so that the prescription dose of 76 Gy(RBE) or 66 Gy(RBE) would be delivered to 99% of the clinical target volume in 20 fractions. Three beams were used for tabletop bolus plan and IMPT plan, whereas two beams were used in the applicator plan because the gantry angle available was limited due to potential collision to patient and couch. The normal liver, colon, and skin were considered as organs at risk (OARs). Results: The target heterogeneity index (HI = D_5/D_9_5) was 1.03 on average in each planning technique. The mean dose to the normal liver was considerably less than 20 Gy(RBE) in all cases. The dose to the skin could be reduced by 20 Gy(RBE) on average in the IMPT plan compared to the applicator plan. Conclusion: It has been confirmed that all treatment techniques met the dosimetric criteria for the OARs and could be implemented clinically.

  12. SU-F-T-189: Dosimetric Comparison of Spot-Scanning Proton Therapy Techniques for Liver Tumors Close to the Skin Surface

    Energy Technology Data Exchange (ETDEWEB)

    Takao, S; Matsuzaki, Y [Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido (Japan); Matsuura, T; Umegaki, K [Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido (Japan); Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido (Japan); Fujii, Y; Fujii, T [Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan); Katoh, N [Department of Radiation Oncology, Hokkaido University Hospital, Sapporo, Hokkaido (Japan); Shimizu, S; Shirato, H [Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido (Japan); Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan)

    2016-06-15

    Purpose: Spot-scanning technique has been utilized to achieve conformal dose distribution to large and complicated tumors. This technique generally does not require patient-specific devices such as aperture and compensator. The commercially available spot-scanning proton therapy (SSPT) systems, however, cannot deliver proton beams to the region shallower than 4 g/cm2. Therefore some range compensation device is required to treat superficial tumors with SSPT. This study shows dosimetric comparison of the following treatment techniques: (i) with a tabletop bolus, (ii) with a nozzle-mounted applicator, and (iii) without any devices and using intensity-modulated proton therapy (IMPT) technique. Methods: The applicator composed of a combination of a mini-ridge filter and a range shifter has been manufactured by Hitachi, Ltd., and the tabletop bolus was made by .decimal, Inc. Both devices have been clinically implemented in our facility. Three patients with liver tumors close to the skin surface were examined in this study. Each treatment plan was optimized so that the prescription dose of 76 Gy(RBE) or 66 Gy(RBE) would be delivered to 99% of the clinical target volume in 20 fractions. Three beams were used for tabletop bolus plan and IMPT plan, whereas two beams were used in the applicator plan because the gantry angle available was limited due to potential collision to patient and couch. The normal liver, colon, and skin were considered as organs at risk (OARs). Results: The target heterogeneity index (HI = D{sub 5}/D{sub 95}) was 1.03 on average in each planning technique. The mean dose to the normal liver was considerably less than 20 Gy(RBE) in all cases. The dose to the skin could be reduced by 20 Gy(RBE) on average in the IMPT plan compared to the applicator plan. Conclusion: It has been confirmed that all treatment techniques met the dosimetric criteria for the OARs and could be implemented clinically.

  13. Determination of reference values for intraocular pressure and Schirmer tear test results in clinically normal domestic donkeys (Equus asinus).

    Science.gov (United States)

    Selk Ghaffari, Masoud; Sabzevari, Amin; Ghamsari, SeyedMehdi; Shad, Hussein

    2017-11-25

    This study was conducted to establish normal reference range for the Schirmer tear test (STT) and intraocular pressure (IOP) in clinically normal donkeys for use in clinical practice. Sixteen adult Ethiopian domestic donkeys were used in this study. Complete ophthalmic examinations were performed without chemical restraint. STT values were evaluated in both eyes of all donkeys using a commercial STT strip. IOP was measured in both eyes with a Tono-Pen Vet (Reichert. USA) without using regional nerve blocks. STT values for all eyes (n=32) were 22.1±6.9 mm/minute with a range of 13-35 mm/minute. Comparison of mean STT values between right (n=16) and left eyes (n=16) showed no differences (P=0.6). Mean ±sd IOP values by applanation tonometry were 17.8±3.7 mmHg (range 13.5-24.5 mmHg). Comparison of mean IOP values between right (n=16) and left eyes (n=16) showed no differences (P=0.7). This initial survey provides means and ranges for IOP and STT values in donkeys. These data will assist veterinary ophthalmologists in more accurate diagnosis and management of ophthalmic diseases in donkeys, including keratoconjunctivitis sicca and glaucoma. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Measuring the nose in septorhinoplasty patients: ultrasonographic standard values and clinical correlations.

    Science.gov (United States)

    Stenner, Markus; Koopmann, Mario; Rudack, Claudia

    2017-02-01

    Although septorhinoplasty is the most commonly performed operation in plastic surgery, and the surgical plan as well as its outcome is directly related to the configuration of the anatomical structures in the nose, these are not routinely assessed preoperatively. The aim of our study was to evaluate the nasal soft tissue and cartilaginous structures by means of high-resolution ultrasonography to set up clinical correlations and standard values. We examined 44 patients before septorhinoplasty by high-resolution ultrasonography in noncontact mode. All pictures were quantitatively evaluated by measuring 13 lengths and 4 ratios. All patients underwent a rhinomanometry measuring the nasal air flow. Besides others, men as well as older patients have a significantly thicker alar cartilage. Patients with thinner alar cartilages have a significantly smaller interdomal distance as well as significantly thinner upper lateral cartilages. The soft tissue above the bony dorsum was significantly thicker in older patients. Younger patients have significantly thicker soft tissue in relation to their cartilage. Patients with thicker soft tissue and thinner cartilage have a smaller tip. The interdomal distance and the thickness of the cartilaginous septum significantly correlated with the nasal air flow. We set up standard values of nasal structures in septorhinoplasty patients which can be used as reference values. By judging cartilage and soft tissue characteristics preoperatively, relevant factors for distinct procedures could be analyzed and the surgical steps can be better planned. Visualization by ultrasonography enables the surgeon to achieve treatment goals in a more predictable fashion.

  15. Clinical value of diffusion-weighted MR imaging in acute contusion of spinal cord

    International Nuclear Information System (INIS)

    Zhang Jinsong; Huan Yi; Sun Lijun; Zhao Haitao; Ge Yali; Chang Yingjuan; Yang Chunmin

    2005-01-01

    Objective: To study the clinical value of diffusion-weighted MR imaging (DWI) in acute contusion of spinal cord. Methods: Eighteen cases with acute contusion of spinal cord were examined with routine MRI and DWI, including single-shot DWI (ssh-DWI) in 2 cases and multi-shot DWI (msh-DWI) in 16 cases, on a 1.5-tesla MR system within 72 h post-trauma. Results: Two cases examined by ssh-DWI showed local lesions with significant high signals, but ssh-DWI images could not be used to measure apparent diffusion coefficient (ADC) value due to its weak resolution. Other 16 cases examined by msh-DWI showed better images and were classified into three categories depending on different degrees of tissue injury and characteristics of DWI: (1) Edema-type: ten cases presented DWI high signals with different degree in local lesions. There were significant difference of ADC values between lesions and normal parts (t=7.515, P 2 WI heterogeneous high signals and T 1 WI low signals due to prominent hemorrhage. Conclusion: DWI of the spinal cord provided satisfactory images and was a useful method for visualizing the injury cord in the super-early stage, helping determine integrity and compression degree of spinal cord and detecting hemorrhage. (authors)

  16. The induction of somatic mutations by high-LET radiation observed using the Drosophila assay system

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Takatsuji, Toshihiro; Nagano, Masaaki; Hoshi, Masaharu; Takada, Jun; Endo, Satoru

    1999-01-01

    To evaluate the mutagenic potential of high-LET radiation, an analysis was made on the production of somatic mutations by 252 Cf fission neutron s and heavy particle ions accelerated by a synchrotron. A Drosophila strain that allows simultaneous detection of two types of mutations in an identical fly was constructed. One was a wing-hair mutation and the other was an eye-color mosaic spot mutation. Measurements were made using a combined assay system of both mutation assays. Larvae were exposed to radiation at the age of post-ovipositional day-3. The efficiency of 252 Cf neutrons for inducing wing-hair mosaic spots was very high, the relative biological effectiveness (RBE) = 8.5, but the efficiency for eye-color mosaic spot was nearly equal (RBE = 1.2) to that of 137 Cs γ-rays. The RBE of carbon ions for inducing wing-hair mosaic spots increased as an increase in LET values. The RBE for the induction of eye-color mutants did not change with LET. These relationships suggest that more complex types of DNA damages such as non-rejoinable strand break or clustered double strand break, which increase with LET may be responsible for the induction of wing-hair mutation, while simpler forms of molecular damage may induce a reversion in the white-ivory allele. (M.N.)

  17. Health-service Use in Women with Binge Eating Disorders

    Science.gov (United States)

    Dickerson, John; DeBar, Lynn; Perrin, Nancy A.; Lynch, Frances; Wilson, G. Terence; Rosselli, Francine; Kraemer, Helena C.; Striegel-Moore, Ruth H.

    2014-01-01

    Objective To compare health-care utilization between participants who met DSM-IV criteria for Binge Eating Disorder (BED) and those engaged in Recurrent Binge Eating (RBE) and to evaluate whether objective binge eating (OBE) days, a key measurement for diagnosing BED, predicted health-care costs. Method We obtained utilization and cost data from electronic medical records to augment patient reported data for 100 adult female members of a large health maintenance organization (HMO) who were enrolled in a randomized clinical trial to treat binge eating. Results Total costs did not differ between the BED and RBE groups (β=−0.117, z=−0.48, p=0.629), nor did the number of OBE days predictor total costs (β= −0.017, z=−1.01, p=0.313). Conclusions Findings suggest that the medical impairment, as assessed through health care costs, caused by BED may not be greater than impairment caused by RBE. The current threshold number of two OBE days/week as a criterion for BED may need to be reconsidered PMID:21823138

  18. Clinical relevance and prognostic value of radiographic findings in Zenker's diverticulum.

    Science.gov (United States)

    Mantsopoulos, Konstantinos; Psychogios, Georgios; Karatzanis, Alexander; Künzel, Julian; Lell, Michael; Zenk, Johannes; Koch, Michael

    2014-03-01

    The aim of this study was to evaluate the clinical relevance and prognostic value of preoperative and postoperative oesophagography in patients with Zenker's diverticulum. The medical records of 155 patients who underwent surgical treatment (with an endoscopic or transcervical approach) for Zenker's diverticulum between 1992 and 2010 in a tertiary referral centre were retrospectively evaluated. The size of the diverticula on oesophagography, recognizable muscular septum, and protection of the diverticulum were assessed relative to the surgical procedures performed. The incidence of diverticular remnants on postoperative oesophagography was also assessed relative to the surgical procedure. It was investigated whether the detection of a residual pharyngeal pouch and filling of it with contrast medium were related to the patients' immediate postoperative symptoms and the development of symptomatic recurrence. Larger diverticula (Brombart III-IV) were manageable significantly more often with endoscopic procedures (P = 0.007). Residual diverticulum and filling with contrast medium were strongly associated with prolonged dysphagia immediately postoperatively (P = 0.005 and P = 0.009, respectively). However, these parameters failed to correlate significantly with a symptomatic recurrence. Preoperative oesophagography proved to be extremely important for surgical planning, with the surgeon's personal preference seeming to be the driving indicator in many cases. Postoperative oesophagography is only useful for excluding postoperative complications in the immediate postoperative phase and did not have a prognostic value as to a recurrence of the disease.

  19. Biological implications and clinical value of mir-210 in gastrointestinal cancer.

    Science.gov (United States)

    Yang, Wanli; Ma, Jiaojiao; Zhou, Wei; Zhou, Xin; Cao, Bo; Fan, Daiming; Hong, Liu

    2017-06-01

    Hypoxia, a common feature of tumor microenvironment, is known to accelerate tumor development and growth by promoting the formation of a neoplastic environment. Recent studies have provided a wealth of evidence that miRNAs are significant members of the adaptive response to low oxygen in tumors. miR-210 is one of the hypoxia-induced miRNAs, which has been reported extensively in cancer researches. However, there is no systematic discussion about the role of miR-210 in gastrointestinal cancer. We conducted a literature research in database including PubMed, Elsevier Science Direct and Medline before 16 September 2016, in order to collect articles of miR-210 in gastrointestinal cancer. Areas covered: In the present review, we mainly discuss the following aspects: hypoxia-induced dysregulation of miR-210, the expression of miR-210 and tumorigenesis, the resultant changes of miR-210 targets and its roles in different types of gastrointestinal cancer progression, the diagnostic, therapeutic and prognostic value of miR-210 in gastrointestinal cancer. Expert commentary: Numerous researches have demonstrated the values of miR-210 in cancer diagnosis, prognosis and targeted therapies, especially in gastrointestinal cancers. However, there are also some existing problems and challenges in translating the new research findings into clinical utility. Further investigations and studies are still urgently required.

  20. Integration of TP53, DREAM, MMB-FOXM1 and RB-E2F target gene analyses identifies cell cycle gene regulatory networks.

    Science.gov (United States)

    Fischer, Martin; Grossmann, Patrick; Padi, Megha; DeCaprio, James A

    2016-07-27

    Cell cycle (CC) and TP53 regulatory networks are frequently deregulated in cancer. While numerous genome-wide studies of TP53 and CC-regulated genes have been performed, significant variation between studies has made it difficult to assess regulation of any given gene of interest. To overcome the limitation of individual studies, we developed a meta-analysis approach to identify high confidence target genes that reflect their frequency of identification in independent datasets. Gene regulatory networks were generated by comparing differential expression of TP53 and CC-regulated genes with chromatin immunoprecipitation studies for TP53, RB1, E2F, DREAM, B-MYB, FOXM1 and MuvB. RNA-seq data from p21-null cells revealed that gene downregulation by TP53 generally requires p21 (CDKN1A). Genes downregulated by TP53 were also identified as CC genes bound by the DREAM complex. The transcription factors RB, E2F1 and E2F7 bind to a subset of DREAM target genes that function in G1/S of the CC while B-MYB, FOXM1 and MuvB control G2/M gene expression. Our approach yields high confidence ranked target gene maps for TP53, DREAM, MMB-FOXM1 and RB-E2F and enables prediction and distinction of CC regulation. A web-based atlas at www.targetgenereg.org enables assessing the regulation of any human gene of interest. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. Monte Carlo based dosimetry and treatment planning for neutron capture therapy of brain tumors

    International Nuclear Information System (INIS)

    Zamenhof, R.G.; Clement, S.D.; Harling, O.K.; Brenner, J.F.; Wazer, D.E.; Madoc-Jones, H.; Yanch, J.C.

    1990-01-01

    Monte Carlo based dosimetry and computer-aided treatment planning for neutron capture therapy have been developed to provide the necessary link between physical dosimetric measurements performed on the MITR-II epithermal-neutron beams and the need of the radiation oncologist to synthesize large amounts of dosimetric data into a clinically meaningful treatment plan for each individual patient. Monte Carlo simulation has been employed to characterize the spatial dose distributions within a skull/brain model irradiated by an epithermal-neutron beam designed for neutron capture therapy applications. The geometry and elemental composition employed for the mathematical skull/brain model and the neutron and photon fluence-to-dose conversion formalism are presented. A treatment planning program, NCTPLAN, developed specifically for neutron capture therapy, is described. Examples are presented illustrating both one and two-dimensional dose distributions obtainable within the brain with an experimental epithermal-neutron beam, together with beam quality and treatment plan efficacy criteria which have been formulated for neutron capture therapy. The incorporation of three-dimensional computed tomographic image data into the treatment planning procedure is illustrated. The experimental epithermal-neutron beam has a maximum usable circular diameter of 20 cm, and with 30 ppm of B-10 in tumor and 3 ppm of B-10 in blood, it produces a beam-axis advantage depth of 7.4 cm, a beam-axis advantage ratio of 1.83, a global advantage ratio of 1.70, and an advantage depth RBE-dose rate to tumor of 20.6 RBE-cGy/min (cJ/kg-min). These characteristics make this beam well suited for clinical applications, enabling an RBE-dose of 2,000 RBE-cGy/min (cJ/kg-min) to be delivered to tumor at brain midline in six fractions with a treatment time of approximately 16 minutes per fraction

  2. The progress in radiotherapy techniques and it's clinical implications

    International Nuclear Information System (INIS)

    Reinfuss, M.; Walasek, T.; Byrski, E.; Blecharz, P.

    2011-01-01

    Three modem radiotherapy techniques were introduced into clinical practice at the onset of the 21 st century - stereotactic radiation therapy (SRT), proton therapy and carbon-ion radiotherapy. Our paper summarizes the basic principles of physics, as well as the technical reqirements and clinical indications for those techniques. SRT is applied for intracranial diseases (arteriovenous malformations, acoustic nerve neuromas, brain metastases, skull base tumors) and in such cases it is referred to as stereotactic radiosurgery (SRS). Techniques used during SRS include GammaKnife, CyberKnife and dedicated linacs. SRT can also be applied for extracranial disease (non-small cell lung cancer, lung metastases, spinal and perispinal tumors, primary liver tumors, breast cancer, pancreatic tumors, prostate cancer, head and neck tumors) and in such cases it is referred to as stereotactic body radiation therapy (SBRT). Eye melanomas, skull base and cervical spine chordomas and chordosarcomas, as well as childhood neoplasms, are considered to be the classic indications for proton therapy. Clinical trials are currently conducted to investigate the usefulness of proton beam in therapy of non-small cell lung cancer, prostate cancer, head and neck tumors, primary liver and oesophageal cancer Carbon-ion radiotherapy is presumed to be more advantageous than proton therapy because of its higher relative biological effectiveness (RBE) and possibility of real-time control of the irradiated volume under PET visualization. The basic indications for carbon-ion therapy are salivary glands neoplasms, selected types of soft tissue and bone sarcomas, skull base chordomas and chordosarcomas, paranasal sinus neoplasms, primary liver cancers and inoperable rectal adenocarcinoma recurrences. (authors)

  3. Sensitivity, specificity and predictive value of blood cultures from cattle clinically suspected of bacterial endocarditis

    DEFF Research Database (Denmark)

    Houe, Hans; Eriksen, L.; Jungersen, Gregers

    1993-01-01

    This study investigated the number of blood culture-positive cattle among 215 animals clinically suspected of having bacterial endocarditis. For animals that were necropsied, the sensitivity, specificity and predictive value of the diagnosis of endocarditis were calculated on the basis...... of the isolation of the causative bacteria from blood. Furthermore, it was investigated whether the glutaraldehyde coagulation time, total leucocyte count, per cent neutrophil granulocytes, pulse rate and duration of disease could help to discriminate endocarditis from other diseases. Among 138 animals necropsied...... the sensitivity, specificity and predictive value of blood cultivation were 70.7 per cent, 93.8 per cent and 89.1 per cent, respectively. None of the other measurements could be used to discriminate between endocarditis and non-endocarditis cases....

  4. Clinical relevance of the apparent diffusion coefficient value of metastatic bone tumours on diffusion-weighted MRI images: differences according to the types of primary tumour, the affected bones, and clinical factors.

    Science.gov (United States)

    Cha, M J; Yoon, Y C

    2015-10-01

    To evaluate whether the apparent diffusion coefficient (ADC) of metastatic bone tumours on diffusion-weighted magnetic resonance imaging (MRI) images differs according to the type of primary cancer, the affected bone, and clinical factors. For this retrospective study, two radiologists reviewed MRI images, including ADC maps, of 67 patients (M:F=38:29; median age, 48 years) who were diagnosed with bone metastasis by means of histological or clinical confirmation. The primary tumours included 29 lung adenocarcinomas, 15 invasive ductal adenocarcinomas of the breast, 13 hepatocellular carcinomas, six prostatic carcinomas, and four renal cell carcinomas. ADC values of the metastatic tumour were compared according to the type of primary malignancy, the affected bone, and the age and sex of the patient using Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction. In addition, pre-contrast CT images were available in 38 of 67 patients; a subanalysis of the CT radiodensity and ADC values were performed with Spearman correlation. The mean, standard deviation, and minimum and maximum values of the ADC of metastatic bone tumours did not differ significantly according to type of primary malignancy, the affected bone, or clinical variables (p>0.1). The ADC value was not significantly correlated with CT radiodensity (p=0.24). Intra- and interobserver agreements for the mean ADC values were excellent (intra-observer: p=0.98; interobserver: p=0.98). Assessment of the ADC value of metastatic bone tumours is not reliable for differentiation of the type of primary cancer. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  5. Clinical relevance and discriminatory value of elevated liver aminotransferase levels for dengue severity.

    Science.gov (United States)

    Lee, Linda K; Gan, Victor C; Lee, Vernon J; Tan, Adriana S; Leo, Yee Sin; Lye, David C

    2012-01-01

    Elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) is prominent in acute dengue illness. The World Health Organization (WHO) 2009 dengue guidelines defined AST or ALT ≥ 1000 units/liter (U/L) as a criterion for severe dengue. We aimed to assess the clinical relevance and discriminatory value of AST or ALT for dengue hemorrhagic fever (DHF) and severe dengue. We retrospectively studied and classified polymerase chain reaction positive dengue patients from 2006 to 2008 treated at Tan Tock Seng Hospital, Singapore according to WHO 1997 and 2009 criteria for dengue severity. Of 690 dengue patients, 31% had DHF and 24% severe dengue. Elevated AST and ALT occurred in 86% and 46%, respectively. Seven had AST or ALT ≥ 1000 U/L. None had acute liver failure but one patient died. Median AST and ALT values were significantly higher with increasing dengue severity by both WHO 1997 and 2009 criteria. However, they were poorly discriminatory between non-severe and severe dengue (e.g., AST area under the receiver operating characteristic [ROC] curve=0.62; 95% confidence interval [CI]: 0.57-0.67) and between dengue fever (DF) and DHF (AST area under the ROC curve=0.56; 95% CI: 0.52-0.61). There was significant overlap in AST and ALT values among patients with dengue with or without warning signs and severe dengue, and between those with DF and DHF. Although aminotransferase levels increased in conjunction with dengue severity, AST or ALT values did not discriminate between DF and DHF or non-severe and severe dengue.

  6. CLINICAL-PHARMACOLOGICAL VALUE OF TREATMENT EFFICIENCY OF BHP-PATIENTS BY ANTITHROMBOTIC THERAPY

    Directory of Open Access Journals (Sweden)

    A.A. Svistunov

    2007-09-01

    Full Text Available Patients with BHP need in pharmacological treatment of thrombosis the most often in the first 3 cases because has dysfunctions of platelets and coagulation. According to results of analysis of efficiency antithrombotic therapy in BHP-patients confirmed clinical and biochemical influence antithrombotic therapy by Ticlid 250 mg twice on the day in comparison with Aspirin 100 mg and Dipiridomol 25 mg on the basic therapy of the BHP by Permixon 160 mg. The received results have had statistically meant differences. Manifestation of BHP and value QOL and others urodynamic complications most often appear on the basic specific monotherapy of BHP and lost after antithrombotic therapy for 1-3 months. The important complications of antithrombotic therapy of BHP-patients did not observe.

  7. The diagnostic value of the combination of patient characteristics, history, and clinical shoulder tests for the diagnosis of rotator cuff tear

    NARCIS (Netherlands)

    van Kampen, D.A.; van den Berg, T.; van der Woude, H.J.; Castelein, R.M.; Scholtes, V.A.B.; Terwee, C.B.; Willems, W.J.

    2014-01-01

    Background: It is unknown which combination of patient information and clinical tests might be optimal for the diagnosis of rotator cuff tears. This study aimed to determine the diagnostic value of nine individual clinical tests for evaluating rotator cuff tear and to develop a prediction model for

  8. Dose estimation of heavy ion beam by microdosimetry. Examination of the method to estimate biological effect from physical measurement of radiation quality

    International Nuclear Information System (INIS)

    Kase, Yuki; Sakama, Makoto; Tsuzuki, Daigo; Abe, Kyoko; Saotome, Naoya; Matsufuji, Naruhiro; Kanai, Tatsuaki; Matsumoto, Kouki; Furusawa, Yoshiya

    2007-01-01

    The absorbed dose (AD) of heavy ion (HI) beam (here, carbon beam) in HI therapy (unit, EGy) (D st ) to exert the actual clinical effect is for the irradiation of tumors deep in the body and is thus estimated by AD corrected with the relative biological effectiveness (RBE) of clinical endpoint: i.e., the relation is expressed by the equation RBE=D st /D rad | same-effect (D rad is AD of the reference X-ray to yield the same effect as the HI used for the intended clinical endpoint). This paper describes the process of the estimation in the title with consideration of depth dependences of AD of HI in accordance to Bragg curve, and of biological AD as determined by colony assay of human salivary gland tumor cells: in NIRS, the desired AD in HI therapy is calculated by multiplying 1.5 to physically measured AD of HI at RBE 10% (10% survival of the cells). This factor has been obtained by microdosimetry of Heavy Ion Medical Accelerator in Chiba (HIMAC) ions in NIRS with a small spherical proportional counter (LET-1/2, Far West Technology) of the diameter 1.27 cm having the tissue equivalent plastic wall and chamber filled with 4.4 kPa of propane-based gas to make the tissue-equivalence size 1.0 μm diameter. The measuring principle is based on the microdosimetric kinetic model reported previously. The calculated dose is found to agree with AD in HI therapeutic planning within 10% fluctuation. (R.T.)

  9. Dosimetry of bone metastases in targeted radionuclide therapy with alpha-emitting {sup 223}Ra-dichloride

    Energy Technology Data Exchange (ETDEWEB)

    Pacilio, Massimiliano [Azienda Ospealiera San Camillo Forlianini, Rome (Italy). Dept. of Medical Physics; Ventroni, Guido; Mango, Lucio [Azienda Ospealiera San Camillo Forlianini, Rome (Italy). Dept. of Nuclear Medicin; De Vincentis, Giuseppe; Di Castro, Elisabetta; Frantellizzi, Viviana; Follacchio, Giulia Anna; Garkavaya, Tatiana [Rome Univ. (Italy). Dept. of Radiological, Oncological and Anatomo Pathological Sciences; Cassano, Bartolomeo; Lorenzon, Leda [Rome Univ. (Italy). Postgraduate School of Medical Physics; Pellegrini, Rosanna; Pani, Roberto [Rome Univ. (Italy). Dept. of Molecular Medicine; Ialongo, Pasquale [Azienda Ospealiera San Camillo Forlianini, Rome (Italy). Dept. of Radiology

    2016-01-15

    percent uptake of {sup 99m}Tc and {sup 223}Ra (activity extrapolated to t = 0) were significantly correlated. The feasibility of in vivo quantitative imaging in {sup 223}Ra therapy was confirmed. The lesion uptake of {sup 223}Ra-dichloride was significantly correlated with that of {sup 99m}Tc-MDP. The D{sub RBE} to lesions per unit administered activity was much higher than that of other bone-seeking radiopharmaceuticals, but considering a standard administration of 21 MBq (six injections of 50 kBq/kg to a 70-kg patient), the mean cumulative value of D{sub RBE} was about 19 Gy, and was therefore in the range of those of other radiopharmaceuticals. The macrodosimetry of bone metastases in treatments with {sup 223}Ra-dichloride is feasible, but more work is needed to demonstrate its helpfulness in predicting clinical outcomes. (orig.)

  10. Assessment of baroreflex sensitivity from spontaneous oscillations of blood pressure and heart rate: proven clinical value?

    International Nuclear Information System (INIS)

    Pinna, Gian Domenico; Maestri, Roberto; La Rovere, Maria Teresa

    2015-01-01

    The baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) is a key mechanism contributing to the neural regulation of the cardiovascular system. Several methods have been proposed so far to assess BRS by analyzing the spontaneous beat-to-beat fluctuations of arterial blood pressure and heart rate. These methods are inherently simple, non-invasive and low-cost. This study is an attempt to address the question of whether spontaneous baroreflex methods have proven to be of value in the clinical setting. In the first part of this article, we critically review most representative clinical studies using spontaneous BRS techniques either for risk stratification or treatment evaluation, these being major issues in the clinical management of the patients. In the second part, we address two important aspects of spontaneous BRS measurements: measurability and reliability. Estimation of BRS in the studies selected for the review was performed according to the sequence, transfer function, alpha-index and phase-rectified signal averaging method. Arterial blood pressure was recorded non-invasively during supine, short-term (<30 min) laboratory recordings. The conclusion from this review is that spontaneous BRS techniques have been shown to be of great value in clinical practice but further work is needed to confirm the validity of previous findings and to widen the field of clinical applications. Measurability and reliability can be a major issue in the measurement of spontaneous BRS, particularly in some patient populations like post-myocardial infarction and heart failure patents. Main causes of poor measurability are: non-sinus rhythm, a high rate of ectopic beats and the need for recorded time series of RR interval and arterial blood pressure to satisfy the constraints of the different BRS estimation algorithms. As for reliability, within-subject variability is rather high in the measurements of spontaneous BRS and, therefore, should be carefully taken into account

  11. Evidence That a Psychopathology Interactome Has Diagnostic Value, Predicting Clinical Needs: An Experience Sampling Study

    Science.gov (United States)

    van Os, Jim; Lataster, Tineke; Delespaul, Philippe; Wichers, Marieke; Myin-Germeys, Inez

    2014-01-01

    Background For the purpose of diagnosis, psychopathology can be represented as categories of mental disorder, symptom dimensions or symptom networks. Also, psychopathology can be assessed at different levels of temporal resolution (monthly episodes, daily fluctuating symptoms, momentary fluctuating mental states). We tested the diagnostic value, in terms of prediction of treatment needs, of the combination of symptom networks and momentary assessment level. Method Fifty-seven patients with a psychotic disorder participated in an ESM study, capturing psychotic experiences, emotions and circumstances at 10 semi-random moments in the flow of daily life over a period of 6 days. Symptoms were assessed by interview with the Positive and Negative Syndrome Scale (PANSS); treatment needs were assessed using the Camberwell Assessment of Need (CAN). Results Psychotic symptoms assessed with the PANSS (Clinical Psychotic Symptoms) were strongly associated with psychotic experiences assessed with ESM (Momentary Psychotic Experiences). However, the degree to which Momentary Psychotic Experiences manifested as Clinical Psychotic Symptoms was determined by level of momentary negative affect (higher levels increasing probability of Momentary Psychotic Experiences manifesting as Clinical Psychotic Symptoms), momentary positive affect (higher levels decreasing probability of Clinical Psychotic Symptoms), greater persistence of Momentary Psychotic Experiences (persistence predicting increased probability of Clinical Psychotic Symptoms) and momentary environmental stress associated with events and activities (higher levels increasing probability of Clinical Psychotic Symptoms). Similarly, the degree to which momentary visual or auditory hallucinations manifested as Clinical Psychotic Symptoms was strongly contingent on the level of accompanying momentary paranoid delusional ideation. Momentary Psychotic Experiences were associated with CAN unmet treatment needs, over and above PANSS

  12. Value of Prophylactic Postoperative Antibiotic Therapy after Bimaxillary Orthognathic Surgery: A Clinical Trial

    Directory of Open Access Journals (Sweden)

    Majid Eshghpour

    2014-10-01

    Full Text Available Introduction: Antibiotic therapy before or after orthognathic surgery is commonly recommended by surgeons to minimize the risk of wound infection. This article evaluates the value of Prophylactic antibiotic therapy in order to diminish the incidence of postoperative wound infection after orthognathic surgery.   Materials and Methods: Fifty candidates for bimaxillary orthognathic surgery were divided into cases and controls. Cefazolin (1g was administered intravenously to all participants 30 mins prior to surgery followed by a similar dose 4 hours later. Case-group patients ingested amoxicillin (500 mg orally for 7 days after surgery. Postoperative wound infection was assessed using clinical features, and the P-value significance was set at P  Results: Both groups were similar according to gender, age, and operating time. During the follow-up period no infection was observed in either the case or control group.   Conclusion:  The results of this study suggest that long-term postoperative antibiotic therapy is not essential for the prevention of postoperative infection, and that application of aseptic surgical technique and hygiene instruction after surgery are sufficient.

  13. Clinical value of 99Tcm-octreotide SPECT/CT in diagnostics of lung cancer

    International Nuclear Information System (INIS)

    Liu Xiaofang; Li Mei; Liu Yong; Li Ran; Xu Jie; Sun yongchang; Dai Haojie

    2012-01-01

    Objective: To evaluate the clinical value of 99 Tc m -Octreotide SPECT-CT in the diagnosis of lung cancer. Methods: Sixty-five consecutive patients with suspected lung cancer received intravenous injection of 740 MBq 99 Tc m -Octreotide and additional SPECT images of the chest were performed at 4h post injection. The SPECT/CT images were interpreted separately. The tumor uptake of 99 Tc m -Octreotide was visually determined and then measured and expressed as the activity ratio of tumor to normal tissues (T/N). The differences between lung cancer and benign lung lesion and between SCLC and NSCLC, and between adenocarcinoma and squamous carcinoma were studied by statistical analysis. Moreover, the receiver operating characteristic ROC curves were plotted and the predicted probabilities and areas under the curve were calculated. Results: Fifty-one patients and fourteen patients in 65 cases were diagnosed as lung cancer and benign lung lesion by histopathological analysis, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of 99 Tc m -Octreotide SPECT/CT in diagnosis of lung cancer were 92.2%, 85.7%, 95.9% and 75%, respectively. The area under ROC curve was 0.889 (P 99 Tc m -Octreotide SPECT/CT could play an important role in the diagnosis of lung cancer, and it may be useful for identifying SCLC and NSCLC. (authors)

  14. Clinical implications in laboratory parameter values in acute Kawasaki disease for early diagnosis and proper treatment.

    Science.gov (United States)

    Seo, Yu-Mi; Kang, Hyun-Mi; Lee, Sung-Churl; Yu, Jae-Won; Kil, Hong-Ryang; Rhim, Jung-Woo; Han, Ji-Whan; Lee, Kyung-Yil

    2018-05-01

    This study aimed to analyse laboratory values according to fever duration, and evaluate the relationship across these values during the acute phase of Kawasaki disease (KD) to aid in the early diagnosis for early-presenting KD and incomplete KD patients. Clinical and laboratory data of patients with KD (n=615) were evaluated according to duration of fever at presentation, and were compared between patients with and without coronary artery lesions (CALs). For evaluation of the relationships across laboratory indices, patients with a fever duration of 5 days or 6 days were used (n=204). The mean fever duration was 6.6±2.3 days, and the proportions of patients with CALs was 19.3% (n=114). C-reactive proteins (CRPs) and neutrophil differential values were highest and hemoglobin, albumin, and lymphocyte differential values were lowest in the 6-day group. Patients with CALs had longer total fever duration, higher CRP and neutrophil differential values and lower hemoglobin and albumin values compared to patients without CALs. CRP, albumin, neutrophil differential, and hemoglobin values at the peak inflammation stage of KD showed positive or negative correlations each other. The severity of systemic inflammation in KD was reflected in the laboratory values including CRP, neutrophil differential, albumin, and hemoglobin. Observing changes in these laboratory parameters by repeated examinations prior to the peak of inflammation in acute KD may aid in diagnosis of early-presenting KD patients.

  15. Hematologic reference values for clinically healthy captive golden conures (Guaruba guarouba).

    Science.gov (United States)

    Prioste, Fabíola Eloisa Setim; Zwarg, Ticiana; Teixeira, Rodrigo Hidalgo; Vanstreels, Ralph Eric Thijl; Rocha, Arnaldo; Matushima, Eliana Reiko

    2012-12-01

    Golden conures or ararajubas (Guaruba guarouba) are endangered parrots endemic to the Brazilian Amazon forest. Body mass, blood cell counts, and total plasma protein were determined for 70 clinically healthy golden conures captive at zoologic parks and private breeder facilities in Brazil. Hematologic results (mean +/- SD) were: Erythrocytes 3.6 +/- 0.5 x 10(6) cells/mm3, hemoglobin 12.8 +/- 1.4 g/dl, packed cell volume 46 +/- 3.8%, mean corpuscular volume 132 +/- 20 fl, mean corpuscular hemoglobin (MCH) 36 +/- 5.7 pg, mean corpuscular hemoglobin concentration (MCHC) 28 +/- 3.5%, thrombocytes 26.3 +/- 9.3 x 10(3) cells/mm3, leukocytes 11.9 +/- 4.5 x 10(3) cells/mm3, heterophils 6284 +/- 2715 cells/mm3, lymphocytes 5473 +/- 2408 cells/ mm3, monocytes 113 +/- 162 cells/mm3, eosinophils 10 +/- 42 cells/mm3, basophils 27 +/- 64 cells/mm3. Body mass was 254 +/- 24.9 g and total plasma protein (TPP) was 3.54 +/- 0.58 g/dl. No statistical differences were observed between genders within age groups. Differences between juveniles (J) and adults (A) were identified for TPP (J A), and MCHC (J > A). These results provide reliable reference values for the clinical interpretation of hematologic results for the species. Hematology may be an important tool for population health investigations on free-ranging golden conure populations and will also be essential to survey the health of release candidates in future reintroduction programs.

  16. [Clinical value of angiogenin in predicting the prognosis of patients with idiopathic pulmonary fibrosis].

    Science.gov (United States)

    Bai, Yanling; Zhu, Haiyan; Sun, Qiyu; Gu, Guozhong; Zhang, Lingyu; Li, Ying; Yang, Baofeng

    2017-09-01

    To explore the relationship between angiogenin-1/2 (Ang-1/2) and clinical parameters of idiopathic pulmonary fibrosis (IPF), and to assess the value of Ang-1/2 in predicting the prognosis of patients with IPF. A retrospective analysis was conducted. Ninety-one patients diagnosed as IPF by high resolution CT (HRCT) and lung biopsy admitted to Daqing Oil Field General Hospital from March 2014 to January 2015 were enrolled. The general data, serum parameters and pulmonary function parameters of all patients were collected. After treatment, all of the 91 patients were followed-up to 2 years. The patients were divided into favorable prognosis group and unfavorable prognosis group according to follow-up results. The differences in all parameters between the two groups were compared. The relationship between Ang-1, Ang-2 and lung function parameters was analyzed by Pearson correlation analysis. Cox proportional hazard regression model was used to evaluate the effect of clinical parameters on the prognosis of patients with IPF. The effect of Ang-2 in predicting prognosis of patients with IPF was analyzed by receiver operating characteristic (ROC) curve. During the 2-year follow-up period, 30 of 91 patients showed a favorable prognosis, and 55 showed an unfavorable prognosis with a poor prognosis rate of 64.71%, and 6 patients withdrew from the study due to loss of follow-up and death. Compared with the favorable prognosis group, Ang-2 level in the unfavorable prognosis group was significantly increased (μg/L: 2.88±1.63 vs. 1.89±1.22, t = 2.909, P = 0.005), but Ang-1 only showed a slight increase (μg/L: 28.70±14.26 vs. 25.62±11.95, t = 1.005, P = 0.318). The results of Pearson correlation analysis showed that Ang-2 level was negatively correlated with forced expiratory volume in 1 second (FVC1) and the percentage of carbon monoxide diffusing capacity accounting for the expected value (DLCO%: r value was -0.227 and -0.206, and P value was 0.147 and 0.253, respectively

  17. 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

  18. Regularities in dose field formation for fixation of 252Cf and 60Co sources on the same plane

    International Nuclear Information System (INIS)

    Ivanov, V.N.; Vtyurin, B.M.; Ivanova, L.F.; Kondzhariya, Yu.R.

    1983-01-01

    A computerized study was made of a change in the correlation between the sizes of an irradiated volume and the distribution of sources. Criteria have been established for the utilization of 252 Cf and 60 Co sources of different active length and design placed on the same plane. Reference dose rate and its derivatives have been chosen as the main parameters that characterize a dose field. A dosimetric analysis was performed using the data for an adsorbed dose of neutrons in the tissue, taking account of high RBE of 252 Cf fast neutrons that equals 6-7, and a slight change of the local RBE value near the source resulting from a change of the effective spectrum of neutrons in combination with the growth of a contribution of #betta#-radiation into the summary dose with the removal from the source. The irradiated volume was evaluated by introducing 3 linear parameters - length, thickness and width. It has been shown that the ratio of the length of an irradiated volume to the active length of 252 Cf sources with radionuclide regular linear density changes from 0.7 with the isodose value of 85% up to 0.97 with the isodose value of 60%. For 60 Co sources with a higher linear density of the radionuclide on the edges the lower limit of this value equals 1. Intervals of changes in the rest of parameters have also been defined. The results obtained are presented graphically. The results of the study are used for a dosimetric control of the clinical trials of 252 Cf and 60 Co sources in the treatment of patients with tumors of the tongue, oral cavity fundus, lip and other sites

  19. Elbow Room for Best Practice? Montgomery, Patients' values, and Balanced Decision-Making in Person-Centred Clinical Care.

    Science.gov (United States)

    Herring, Jonathan; Fulford, Kmw; Dunn, Michael; Handa, Ashoki

    2017-11-01

    The UK Supreme Court Montgomery judgment marks a decisive shift in the legal test of duty of care in the context of consent to treatment, from the perspective of the clinician (as represented by Bolam rules) to that of the patient. A majority of commentators on Montgomery have focused on the implications of the judgment for disclosure of risk. In this article, we set risk disclosure in context with three further elements of the judgment: benefits, options, and dialogue. These elements, we argue, taken together with risk disclosure, reflect the origins of the Montgomery ruling in a model of consent based on autonomy of patient choice through shared decision-making with their doctor. This model reflects recent developments in both law and medicine and is widely regarded (by the General Medical Council and others) as representing best practice in contemporary person-centred medicine. So understood, we suggest, the shift marked by Montgomery in the basis of duty of care is a shift in underpinning values: it is a shift from the clinician's interpretation about what would be best for patients to the values of (to what is significant or matters from the perspective of) the particular patient concerned in the decision in question. But the values of the particular patient do not thereby become paramount. The Montgomery test of duty of care requires the values of the particular patient to be balanced alongside the values of a reasonable person in the patient's position. We illustrate some of the practical challenges arising from the balance of considerations required by Montgomery with examples from surgical care. These examples show the extent to which Montgomery, in mirroring the realities of clinical decision-making, provides elbowroom for best practice in person-centred clinical care. © The Author 2017. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Incremental clinical value of ultrasound in men with mammographically confirmed gynecomastia.

    Science.gov (United States)

    Chen, Po-Hao; Slanetz, Priscilla J

    2014-01-01

    To determine whether ultrasound is of any value in male patients presenting with focal symptoms who have classic features of gynecomastia but no concerning findings on mammography. Over a 3-year period, all male patients who underwent mammographic evaluation were identified in this retrospective study. Patients with a mammographic diagnosis of gynecomastia and subsequent breast ultrasound at a large tertiary academic medical center comprised the study cohort. Men whose ultrasound diagnosis differed from the initial mammographic evaluation were analyzed for both additional benign findings as well as findings that warranted biopsy. A total of 353 mammograms were obtained from 327 unique patients (ages 18-95, mean 51 years). Of all mammographic examinations, gynecomastia was the sole finding in 73% (259). In those 259 studies, 85% were further evaluated with ultrasound, in which 6 (2.7%) showed additional benign findings, and 4 (1.8%) showed suspicious findings for which biopsy was recommended. No malignancies were detected in those patients. Furthermore, no malignancies were detected in patients whose mammogram revealed only normal fatty parenchyma or only gynecomastia. In all cases of cancer, mammography revealed visible masses. Judicious use of breast ultrasound in men improves outcome. Our data suggest that targeted ultrasound is of limited value in symptomatic male patients where mammography is negative or reveals only gynecomastia and leads to unnecessary benign biopsies in these patients. When mammography reveals concerning findings, ultrasound adds positively to clinical management. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Incremental clinical value of ultrasound in men with mammographically confirmed gynecomastia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Po-Hao, E-mail: howard_chen@post.harvard.edu [Harvard Medical School, 25 Shattuck Street, Boston, MA 02115 (United States); Department of Radiology, Hospital of University of Pennsylvania, 3400 Spruce Street, Philadlephia, PA 19104 (United States); Slanetz, Priscilla J., E-mail: pslanetz@bidmc.harvard.edu [Harvard Medical School, 25 Shattuck Street, Boston, MA 02115 (United States); Beth Israel Deaconess Medical Center, Department of Radiology, 330 Brookline Avenue, Boston, MA 02215 (United States)

    2014-01-15

    Purpose: To determine whether ultrasound is of any value in male patients presenting with focal symptoms who have classic features of gynecomastia but no concerning findings on mammography. Materials and Methods: Over a 3-year period, all male patients who underwent mammographic evaluation were identified in this retrospective study. Patients with a mammographic diagnosis of gynecomastia and subsequent breast ultrasound at a large tertiary academic medical center comprised the study cohort. Men whose ultrasound diagnosis differed from the initial mammographic evaluation were analyzed for both additional benign findings as well as findings that warranted biopsy. Results: A total of 353 mammograms were obtained from 327 unique patients (ages 18–95, mean 51 years). Of all mammographic examinations, gynecomastia was the sole finding in 73% (259). In those 259 studies, 85% were further evaluated with ultrasound, in which 6 (2.7%) showed additional benign findings, and 4 (1.8%) showed suspicious findings for which biopsy was recommended. No malignancies were detected in those patients. Furthermore, no malignancies were detected in patients whose mammogram revealed only normal fatty parenchyma or only gynecomastia. In all cases of cancer, mammography revealed visible masses. Conclusion: Judicious use of breast ultrasound in men improves outcome. Our data suggest that targeted ultrasound is of limited value in symptomatic male patients where mammography is negative or reveals only gynecomastia and leads to unnecessary benign biopsies in these patients. When mammography reveals concerning findings, ultrasound adds positively to clinical management.

  2. Comparative study of G2 delay and survival after /sup 241/Americium-. cap alpha. and /sup 60/Cobalt-. gamma. irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Luecke-Huhle, C.; Comper, W.; Hieber, L.; Pech, M.

    1982-06-01

    Survival and G2 delay following exposure to either /sup 60/Cobalt-..gamma..-rays or /sup 241/Americium-..cap alpha..-particles were studied in eight mammalian cell lines of human and animal origin including human fibroblasts from normal individuals and from patients with Ataxia telangiectasia or Fanconi's anemia. For both endpoints the effectiveness of alpha particle was greater as compared to ..gamma..-rays. RBE values for G2 delay (4.6-9.2) were in general comparable to RBE values derived from initial slopes of survival curves but higher compared to the ratio of mean inactivation doses. Ataxia cells were particularly sensitive to cell killing by ..gamma..-irradiation, however, showed average sensitivity to ..cap alpha..-particles of high LET. With the exception of Ataxia cells, cell killing and G2 delay seem to be related processes if individual cell cycle parameters are taken into account.

  3. Cellular track model of biological damage to mammalian cell cultures from galactic cosmic rays

    International Nuclear Information System (INIS)

    Cucinotta, F.A.; Katz, R.; Wilson, J.W.; Townsend, L.W.; Nealy, J.E.; Shinn, J.L.

    1991-02-01

    The assessment of biological damage from the galactic cosmic rays (GCR) is a current interest for exploratory class space missions where the highly ionizing, high-energy, high-charge ions (HZE) particles are the major concern. The relative biological effectiveness (RBE) values determined by ground-based experiments with HZE particles are well described by a parametric track theory of cell inactivation. Using the track model and a deterministic GCR transport code, the biological damage to mammalian cell cultures is considered for 1 year in free space at solar minimum for typical spacecraft shielding. Included are the effects of projectile and target fragmentation. The RBE values for the GCR spectrum which are fluence-dependent in the track model are found to be more severe than the quality factors identified by the International Commission on Radiological Protection publication 26 and seem to obey a simple scaling law with the duration period in free space

  4. Cellular track model of biological damage to mammalian cell cultures from galactic cosmic rays

    Science.gov (United States)

    Cucinotta, Francis A.; Katz, Robert; Wilson, John W.; Townsend, Lawrence W.; Nealy, John E.; Shinn, Judy L.

    1991-01-01

    The assessment of biological damage from the galactic cosmic rays (GCR) is a current interest for exploratory class space missions where the highly ionizing, high-energy, high-charge ions (HZE) particles are the major concern. The relative biological effectiveness (RBE) values determined by ground-based experiments with HZE particles are well described by a parametric track theory of cell inactivation. Using the track model and a deterministic GCR transport code, the biological damage to mammalian cell cultures is considered for 1 year in free space at solar minimum for typical spacecraft shielding. Included are the effects of projectile and target fragmentation. The RBE values for the GCR spectrum which are fluence-dependent in the track model are found to be more severe than the quality factors identified by the International Commission on Radiological Protection publication 26 and seem to obey a simple scaling law with the duration period in free space.

  5. Coronary CT angiography: Diagnostic value and clinical challenges.

    Science.gov (United States)

    Sabarudin, Akmal; Sun, Zhonghua

    2013-12-26

    Coronary computed tomography (CT) angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography. Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320- slice CT scanners. Despite the promising diagnostic value, coronary CT angiography is still limited in some areas, such as inferior temporal resolution, motion-related artifacts and high false positive results due to severe calcification. The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners. Prognostic value of coronary CT angiography in coronary artery disease is also discussed, while limitations and challenges of coronary CT angiography are highlighted.

  6. Analysis of clinical value of CT in the diagnosis of pediatric pneumonia and mycoplasma pneumonia

    OpenAIRE

    GONG, LIANG; ZHANG, CHONG-LIN; ZHEN, QING

    2016-01-01

    Pneumonia is an infectious disease of the lung causing mortality. Mycoplasma pneumonia (MP) is an atypical bacterial pneumonia that damages several organs. Lung computed tomography (CT) has been utilized in its identification. The aim of the present study was to examine the value of computed tomography diagnosis for pediatric MP. The present study prospectively analyzed the clinical and imaging data of 1,280 cases of pediatric MP in the out- and inpatient departments from March, 2010 to March...

  7. The clinical value of trans-vaginal ultrasound-guided puncture in the treatment of pelvic abscess

    International Nuclear Information System (INIS)

    Wang Ping; Gong Wei

    2008-01-01

    Objective: To investigate the clinical value of trans-vaginal ultrasound-guided (TVS) puncture in the treatment of pelvic abscess. Methods 30 cases with pelvic abscess were treated by transvaginal ultrasound-guided puncture. The long-dated effects were followed-up. Results: 29 cases were cured by TVS puncture. Operation was performed in 1 patient because of invalid effect. The cure rate was 97%. Conclusion: Ultrasound-guided puncture is a safe and convenient method in the treatment of pelvic abscess. (authors)

  8. Can We Advance Proton Therapy for Prostate? Considering Alternative Beam Angles and Relative Biological Effectiveness Variations When Comparing Against Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Tracy, E-mail: tunderwood@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Department of Medical Physics and Bioengineering, University College London, London (United Kingdom); Giantsoudi, Drosoula; Moteabbed, Maryam; Zietman, Anthony; Efstathiou, Jason; Paganetti, Harald; Lu, Hsiao-Ming [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2016-05-01

    Purpose: For prostate treatments, robust evidence regarding the superiority of either intensity modulated radiation therapy (IMRT) or proton therapy is currently lacking. In this study we investigated the circumstances under which proton therapy should be expected to outperform IMRT, particularly the proton beam orientations and relative biological effectiveness (RBE) assumptions. Methods and Materials: For 8 patients, 4 treatment planning strategies were considered: (A) IMRT; (B) passively scattered standard bilateral (SB) proton beams; (C) passively scattered anterior oblique (AO) proton beams, and (D) AO intensity modulated proton therapy (IMPT). For modalities (B)-(D) the dose and linear energy transfer (LET) distributions were simulated using the TOPAS Monte Carlo platform and RBE was calculated according to 3 different models. Results: Assuming a fixed RBE of 1.1, our implementation of IMRT outperformed SB proton therapy across most normal tissue metrics. For the scattered AO proton plans, application of the variable RBE models resulted in substantial hotspots in rectal RBE weighted dose. For AO IMPT, it was typically not possible to find a plan that simultaneously met the tumor and rectal constraints for both fixed and variable RBE models. Conclusion: If either a fixed RBE of 1.1 or a variable RBE model could be validated in vivo, then it would always be possible to use AO IMPT to dose-boost the prostate and improve normal tissue sparing relative to IMRT. For a cohort without rectum spacer gels, this study (1) underlines the importance of resolving the question of proton RBE within the framework of an IMRT versus proton debate for the prostate and (2) highlights that without further LET/RBE model validation, great care must be taken if AO proton fields are to be considered for prostate treatments.

  9. Interventional management of spine eosinophilic granuloma in children: preliminary investigation of its clinical value

    International Nuclear Information System (INIS)

    He Yu; Wu Chungen; Gu Yifeng; Cheng Yongde

    2011-01-01

    Objective: To assess the clinical value of interventional management in treating spine eosinophilic granuloma in children. Methods: Interventional therapies, including per cutaneous biopsy and percutaneous vertebroplasty (PVP), were carried out in three child patients with five pathologically-proved eosinophilic granuloma lesions, which were localized in the vertebrae. The clinical data were retrospectively analyzed. Visual analogue pain scale (VAS) and Oswesty disability index (ODI) were assessed before and after operation. Results: A total of four operations were successfully carried out in all of three patients. The mean VAS score reduced from 7 before treatment of 1 after treatment. The mean ODI decreased from preoperative 52.5% to postoperative 10.5%. During procedures no significant complications occurred except for cement leakage in some cases. Pain relief and daily activity were remarkably improved after treatment. All patients were followed up for 3 months to 5 years. Conclusion: For the treatment of spine eosinophilic granuloma in children, interventional techniques are mini-invasive, safe and effective therapeutic methods. (authors)

  10. The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low

    NARCIS (Netherlands)

    Graat, Marleen E.; Choi, Goda; Wolthuis, Esther K.; Korevaar, Johanna C.; Spronk, Peter E.; Stoker, Jaap; Vroom, Margreeth B.; Schultz, Marcus J.

    2006-01-01

    INTRODUCTION: The clinical value of daily routine chest radiographs (CXRs) in critically ill patients is unknown. We conducted this study to evaluate how frequently unexpected predefined major abnormalities are identified with daily routine CXRs, and how often these findings lead to a change in care

  11. Relative Biological Effectiveness of Energetic Heavy Ions for Intestinal Tumorigenesis Shows Male Preponderance and Radiation Type and Energy Dependence in APC{sup 1638N/+} Mice

    Energy Technology Data Exchange (ETDEWEB)

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Strawn, Steve J.; Thakor, Hemang; Fan, Ziling [Department of Biochemistry and Molecular & Cellular Biology and Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia (United States); Shay, Jerry W. [Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas (United States); Fornace, Albert J. [Department of Biochemistry and Molecular & Cellular Biology and Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia (United States); Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah (Saudi Arabia); Datta, Kamal, E-mail: kd257@georgetown.edu [Department of Biochemistry and Molecular & Cellular Biology and Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia (United States)

    2016-05-01

    Purpose: There are uncertainties associated with the prediction of colorectal cancer (CRC) risk from highly energetic heavy ion (HZE) radiation. We undertook a comprehensive assessment of intestinal and colonic tumorigenesis induced after exposure to high linear energy transfer (high-LET) HZE radiation spanning a range of doses and LET in a CRC mouse model and compared the results with the effects of low-LET γ radiation. Methods and Materials: Male and female APC{sup 1638N/+} mice (n=20 mice per group) were whole-body exposed to sham-radiation, γ rays, {sup 12}C, {sup 28}Si, or {sup 56}Fe radiation. For the >1 Gy HZE dose, we used γ-ray equitoxic doses calculated using relative biological effectiveness (RBE) determined previously. The mice were euthanized 150 days after irradiation, and intestinal and colon tumor frequency was scored. Results: The highest number of tumors was observed after {sup 28}Si, followed by {sup 56}Fe and {sup 12}C radiation, and tumorigenesis showed a male preponderance, especially after {sup 28}Si. Analysis showed greater tumorigenesis per unit of radiation (per cGy) at lower doses, suggesting either radiation-induced elimination of target cells or tumorigenesis reaching a saturation point at higher doses. Calculation of RBE for intestinal and colon tumorigenesis showed the highest value with {sup 28}Si, and lower doses showed greater RBE relative to higher doses. Conclusions: We have demonstrated that the RBE of heavy ion radiation-induced intestinal and colon tumorigenesis is related to ion energy, LET, gender, and peak RBE is observed at an LET of 69 keV/μm. Our study has implications for understanding risk to astronauts undertaking long duration space missions.

  12. 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)

  13. Exploration of 'over kill effect' of high-LET Ar- and Fe-ions by evaluating the fraction of non-hit cell and interphase death

    International Nuclear Information System (INIS)

    Mehnati, P.; Sasaki, Hiroshi; Morimoto, Shigeko; Yatagai, Fumio; Hanaoka, Fumio; Furusawa, Yoshiya; Kanai, Tatsuaki; Kobayashi, Yasuhiko; Wada, Seiichi

    2005-01-01

    The reason why relative biological effectiveness (RBE) for cell killing fell to less than unity (1.0) with very high-linear energy transfer (LET) heavy-ions ( 40 Ar: 1,640 keV/μm; 56 Fe: 780, 1,200, 2,000 keV/μm) was explored by evaluating the fraction of non-hit cell (time-lapse observation) and cells undergoing interphase death (calculation based on our previous data). Chinese hamster ovary (CHO) cells were exposed to 4 Gy (30% survival dose) of Ar (1,640 keV/μm) or Fe-ions (2,000 keV/μm). About 20% of all cells were judged to be non-hit, and about 10% cells survived radiation damage. About 70% cells died after dividing at least once (reproductive death) or without dividing (interphase death). RBE for reproductive (RBE[R]) and interphase (RBE[I]) death showed a similar LET dependence with maximum around 200 keV/μm. In this LET region, at 30% survival level, about 10% non-survivors underwent interphase death. The corresponding value for very high-LET Fe-ions (2,000 keV/μm) was not particularly high (-15%), whereas that for X-rays was less than 3%. However, reproductive death (67%) predominated over interphase death (33%) even in regard to rather severely damaged cells (1% survival level) after exposure to Fe-ions (2,000 keV/μm). These indicate that interphase death is a type of cell death characteristic for the cells exposed to high-LET radiation and is not caused by 'cellular over kill effect'. Both NHF37 (non-hit fraction at 37% survival) and inactivation cross-section for reproductive death (σ[R]) began to increase when LET exceeded 100 keV/μm. The exclusion of non-hit fraction in the calculation of surviving fraction partially prevented the fall of RBE[R] when LET exceeded 200 keV/μm. On the other hand, the mean number of lethal damage per unit dose (NLD/Gy) showed the same LET-dependent pattern as RBE[R]. These suggest that the increase in non-hit fraction and σ[R] with an increasing LET is caused by enhanced clustering of ionization and DNA damage

  14. Clinical value of plasma endothelin levels in children with cardiovascular diseases

    International Nuclear Information System (INIS)

    Chen Nianfa; Duan Yongqiang

    2009-01-01

    To explore the clinical value of plasma endothelin (ET-1) levels in children with cardiovascular diseases, 77 children with heart failure, obesity, hyperlipemia, fatty liver and hypertension were divided into 5 experimental groups and 21 health children with same age and gender as control group. The plasma levels of ET-1 in these children were tested by RIA. The results showed that plasma levels of ET-1 in 5 experimental groups were 112.8 ± 34.1ng/L, 57.8 ± 19.1ng/L,64.5 ± 25.3ng/L, 74.9 ± 28.4ng/L and 60.7 ± 21.6ng/L, respectively. The ET-1 levels in 5 groups were significantly higher than that in control group (P<0.01). The results indicate the higher plasma ET-1 levels in children are related with cardiovascular diseases, and it is useful in the diagnosis of children cardiovascular diseases. (authors)

  15. On being supervised: getting value from a clinical supervisor and making the relationship work when it is not.

    Science.gov (United States)

    Parker, Stephen; Suetani, Shuichi; Motamarri, Balaji

    2017-12-01

    The importance of clinical supervision is emphasised in psychiatric training programs. Despite this, the purpose and processes of supervision are often poorly defined. There is limited guidance available for trainees about their role in making supervision work. This paper considers the nature of supervision in psychiatric training and provides practical advice to help supervisees take active steps to make supervision work. In obtaining value from supervision, the active role of the supervisee in seeking feedback, finding value in criticism and building autonomy is emphasised. Additionally, the importance of exploring what value a supervisor can offer and maintaining realistic expectations is considered. Trainees can benefit from taking an active role in planning and managing their supervision to maximise their learning.

  16. A practical guide for implementing and maintaining value-added clinical systems learning roles for medical students using a diffusion of innovations framework.

    Science.gov (United States)

    Gonzalo, Jed D; Graaf, Deanna; Ahluwalia, Amarpreet; Wolpaw, Dan R; Thompson, Britta M

    2018-03-21

    After emphasizing biomedical and clinical sciences for over a century, US medical schools are expanding experiential roles that allow students to learn about health care delivery while also adding value to patient care. After developing a program where all 1st-year medical students are integrated into interprofessional care teams to contribute to patient care, authors use a diffusion of innovations framework to explore and identify barriers, facilitators, and best practices for implementing value-added clinical systems learning roles. In 2016, authors conducted 32 clinical-site observations, 29 1:1 interviews with mentors, and four student focus-group interviews. Data were transcribed verbatim, and a thematic analysis was used to identify themes. Authors discussed drafts of the categorization scheme, and agreed upon results and quotations. Of 36 sites implementing the program, 17 (47%) remained, 8 (22%) significantly modified, and 11 (31%) withdrew from the program. Identified strategies for implementing value-added roles included: student education, patient characteristics, patient selection methods, activities performed, and resources. Six themes influencing program implementation and maintenance included: (1) educational benefit, (2) value added to patient care from student work, (3) mentor time and site capacity, (4) student engagement, (5) working relationship between school, site, and students, and, (6) students' continuity at the site. Health systems science is an emerging focus for medical schools, and educators are challenged to design practice-based roles that enhance education and add value to patient care. Health professions' schools implementing value-added roles will need to invest resources and strategize about best-practice strategies to guide efforts.

  17. Establishment of virtual three-dimensional model for intravascular interventional devices and its clinical value

    International Nuclear Information System (INIS)

    Wei Xin; Zhong Liming; Xie Xiaodong; Wang Chaohua; You Jian; Hu Hong; Hu Kongqiong; Zhao Xiaowei

    2012-01-01

    Objective: To explore virtual three-dimensional (3D) model for intravascular interventional devices,the method of preoperative simulation and its value in clinical work. Methods: The virtual models including catheter, guide wire, stent and coil were established by using the 3D moulding software of 3D Studio MAX R3. The interventional preoperative simulation was performed on personal computer including 21 patients of cerebral aneurysm embolization (anterior communicating artery 5, posterior communicating artery 10,middle cerebral artery 3, internal carotid artery 2, and vertebral artery 1), during interventional procedures, the surgeon relied on the simulation results for plastic micro-guide wire, catheter and the release of micro-coils and stents. Results: (1) All the virtual instruments and real instruments had similar shape,the overall tine for constructing virtual model was about 20 hours. The preoperative simulation took 50 to 80 minutes. (2) The simulation result of catheter insertion in the 18 cases had relevant value to guide micro-catheter, molding micro-guide wire tip, and shortened the operating time. For embolization, the simulation results of filling coil and releasing stent were similar to surgical results in 76% of the patients (16/21). (3)For teaching and training, 93% (38/41) of doctors in training believed that preoperative simulation facilitated the understanding of surgery. Conclusions: The method of virtual model of intravascular interventional devices was reliable. The preoperative simulation results could be used to guide practical clinical operation with relatively high degree of similarity, and could play a role in promoting researches on interventional virtual operations. (authors)

  18. The clinical value of three-dimensional contrast-enhanced MR angiography in abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Liu Qi; Lu Jianping; Tian Jianming; Wang Fei; Wang Li; Jin Aiguo; Zeng Hao; Gong Jianguo

    2004-01-01

    Objective: To evaluate the clinical value of three-dimensional contrast-enhanced MR angiography (3D CE-MRA) and its 3D reconstruction in the diagnosis of abdominal aortic aneurysms (AAA). Methods: Sixty-three patients with clinically diagnosed AAA underwent 3D CE-MRA combined with other sequences. 3D CE-MRA was performed with a 3D FISP sequence(TR, TE, FA=3.64 ms, 1.44 ms, 25 degrees, matrix=196 x 512, eff. slice=1.8 mm, FOV 30 cm x 40 cm, acquisition time=18-20 s) after injection of 0.2 mmol Gd-DTPA per kg b. w. A bolus-test was done before angiography to optimize imaging delay time. After 3D CE-MRA a T 1 -weighted sequence was acquired on the axial plane. The source images were subtracted from mask images and transferred to computer workstation, and subsequently post-processed using 3D reconstruction. All sequences were used to depict the type, location, extent, and thrombosis of the AAA, the morphology of its proximal neck, the distal aortoiliac inflow tract, and the relationship with the branches of aorta. The length, diameter, and angle of the aneurysm sac, and proximal and distal arteries were measured. The clinical role was evaluated for treatment planning. Results: High-quality 3D CE-MRA/MRI images were obtained in all patients. Among them, fifty-six had infrarenal AAA, five juxtarenal AAA, and two AAA with suprarenal extension. The mean diameter of aneurysms was 5.3 cm. The thrombosis was thicker than 2.0 cm in 26 patients. 3D CE-MRA clearly demonstrated the morphology and extent of AAA, and its proximal neck and distal aortoiliac inflow tract. The accurate parameters needed by endovascular treatment were gained simultaneously. Aneurysm and its neck depiction at 3D CE-MRA was better than that at DSA. The endovascular and surgical treatment were selected according the images (31 endovascular treatment, 4 surgical treatment, 28 conservative treatment only). The parameters at 3D CE-MRA coincided well with those at DSA in all cases (P>0.1). Conclusion: 3D CE

  19. DianaHealth.com, an On-Line Database Containing Appraisals of the Clinical Value and Appropriateness of Healthcare Interventions: Database Development and Retrospective Analysis.

    Science.gov (United States)

    Bonfill, Xavier; Osorio, Dimelza; Solà, Ivan; Pijoan, Jose Ignacio; Balasso, Valentina; Quintana, Maria Jesús; Puig, Teresa; Bolibar, Ignasi; Urrútia, Gerard; Zamora, Javier; Emparanza, José Ignacio; Gómez de la Cámara, Agustín; Ferreira-González, Ignacio

    2016-01-01

    To describe the development of a novel on-line database aimed to serve as a source of information concerning healthcare interventions appraised for their clinical value and appropriateness by several initiatives worldwide, and to present a retrospective analysis of the appraisals already included in the database. Database development and a retrospective analysis. The database DianaHealth.com is already on-line and it is regularly updated, independent, open access and available in English and Spanish. Initiatives are identified in medical news, in article references, and by contacting experts in the field. We include appraisals in the form of clinical recommendations, expert analyses, conclusions from systematic reviews, and original research that label any health care intervention as low-value or inappropriate. We obtain the information necessary to classify the appraisals according to type of intervention, specialties involved, publication year, authoring initiative, and key words. The database is accessible through a search engine which retrieves a list of appraisals and a link to the website where they were published. DianaHealth.com also provides a brief description of the initiatives and a section where users can report new appraisals or suggest new initiatives. From January 2014 to July 2015, the on-line database included 2940 appraisals from 22 initiatives: eleven campaigns gathering clinical recommendations from scientific societies, five sets of conclusions from literature review, three sets of recommendations from guidelines, two collections of articles on low clinical value in medical journals, and an initiative of our own. We have developed an open access on-line database of appraisals about healthcare interventions considered of low clinical value or inappropriate. DianaHealth.com could help physicians and other stakeholders make better decisions concerning patient care and healthcare systems sustainability. Future efforts should be focused on

  20. DianaHealth.com, an On-Line Database Containing Appraisals of the Clinical Value and Appropriateness of Healthcare Interventions: Database Development and Retrospective Analysis.

    Directory of Open Access Journals (Sweden)

    Xavier Bonfill

    Full Text Available To describe the development of a novel on-line database aimed to serve as a source of information concerning healthcare interventions appraised for their clinical value and appropriateness by several initiatives worldwide, and to present a retrospective analysis of the appraisals already included in the database.Database development and a retrospective analysis. The database DianaHealth.com is already on-line and it is regularly updated, independent, open access and available in English and Spanish. Initiatives are identified in medical news, in article references, and by contacting experts in the field. We include appraisals in the form of clinical recommendations, expert analyses, conclusions from systematic reviews, and original research that label any health care intervention as low-value or inappropriate. We obtain the information necessary to classify the appraisals according to type of intervention, specialties involved, publication year, authoring initiative, and key words. The database is accessible through a search engine which retrieves a list of appraisals and a link to the website where they were published. DianaHealth.com also provides a brief description of the initiatives and a section where users can report new appraisals or suggest new initiatives. From January 2014 to July 2015, the on-line database included 2940 appraisals from 22 initiatives: eleven campaigns gathering clinical recommendations from scientific societies, five sets of conclusions from literature review, three sets of recommendations from guidelines, two collections of articles on low clinical value in medical journals, and an initiative of our own.We have developed an open access on-line database of appraisals about healthcare interventions considered of low clinical value or inappropriate. DianaHealth.com could help physicians and other stakeholders make better decisions concerning patient care and healthcare systems sustainability. Future efforts should be

  1. Predictive value of PSA velocity over early clinical and pathological parameters in patients with localized prostate cancer who undergo radical retropubic prostatectomy

    Directory of Open Access Journals (Sweden)

    Martinez Carlos A.L.

    2004-01-01

    Full Text Available OBJECTIVES: To analyze the behavior of the prostate specific antigen velocity (PSAV in localized prostate adenocarcinoma. MATERIALS AND METHODS: We conducted a retrospective study of 500 men who had localized prostate adenocarcinoma, who underwent radical retropubic prostatectomy between January 1986 and December 1999. The PSAV was calculated for each patient and subsequently, the values were correlated with 5 groups: age, initial PSA value, clinical stage, tumor volume and Gleason score. RESULTS: The behavior of PSAV presented statistic significance with an increment between 1.3 ng/mL and 9.6 ng/mL, ranging from 38.6% and 59.8% when compared with the initial PSA value (p < 0.0001, clinical stage (p = 0.0002, tumor volume (p < 0.0001 and Gleason score (p = 0.0009. CONCLUSION: PSAV up to 2.5 ng/mL/year is associated with factors of good prognosis, such as initial PSA below 10 mg/mL, clinical stage T1, tumor volume below 20% and Gleason score lower than 7.

  2. Clinical value of measurement of pulmonary radioaerosol mucociliary clearance in the work up of primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Munkholm, Mathias; Nielsen, Kim Gjerum; Mortensen, Jann

    2015-01-01

    BACKGROUND: We aimed to evaluate and define the general clinical applicability and impact of pulmonary radioaerosol mucociliary clearance (PRMC) on the work up of patients suspected of having primary ciliary dyskinesia (PCD). In addition, we wanted to evaluate the accuracy of the reference values...... primarily to results from nasal ciliary function testing, to electron microscopic (EM) examination of the ultrastructure of the cilia, and to the final clinical diagnosis. RESULTS: Of the 239 patients, 27 ended up with a final clinical diagnosis of definitive PCD. No patients with a PRMC test...... of the entire lung. Its greatest strength is its ability to reject a suspected PCD diagnosis with great certainty. In our material, this accounted for 2/3 of referred patients. In addition, the test has a high rate of conclusive results. According to our analyses, reference equations on children would benefit...

  3. Effects of organically bound tritium (OBT) on cultured midbrain cells from embryonic mice

    International Nuclear Information System (INIS)

    Wang Bing; Akihiro Shima; Takeshi Yamada; Keiko Watganabe

    1997-01-01

    Objective: Four kinds of organically bound tritium compounds (OBT s ) including 3 H-thymidine, 3 H-uridine, 3 H-arginine and 3 H-glutamic acid, were investigated on proliferation and differentiation of cultured mouse embryonic midbrain cells (MBCs). Methods: MBCs were isolated from day 11 embryos, cultured at a high concentration with the medium containing OBT. Results: Differentiation of MBC was more sensitive to radiation than proliferation. Dose-dependent decrease of DNA and protein contents were also observed. The RBE values, ranging from 4.6 to 8.7, of β rays from OBTs were obtained when compared with X-irradiation at their ID50s (inhibitory dose that reduced assessment value by 50% of the control) on inhibition of cell proliferation and differentiation, and on reduction of DNA and protein contents of the cultures. The mixed exposure to X-rays and one kind of OBTs or to any two kinds of OBTs resulted in more efficiently inhibitory effect on differentiation. Conclusions: MBC culture system was more sensitive to beta radiation from OBTs than to X-rays, which resulted in very high RBE values

  4. Clinical value of SPECT/CT imaging in the diagnosis of bone metastasis

    International Nuclear Information System (INIS)

    Wang Xinhua; Zhao Yanping; Lu Haijian; Dong Zhanfei

    2010-01-01

    Objective: To evaluate the clinical value of 99 Tc m -methylene diphosphonic acid (MDP) SPECT/CT imaging for the diagnosis of bone metastasis. Methods: Patients suspected for bone metastasis and with bone pain of unknown origin were included in this study (n=237). All cases underwent SPECT and CT imaging at 180 min after 99 Tc m -MDP injection. Diagnosis was confirmed by pathology (n=21), more than 2 kinds of radiologieal imaging (MRI, CT, X-ray) (n=106), and clinical follow up in 2 years (n=110). χ 2 -test was used to compare the results of planar and SPECT/CT imaging using SAS 6.12 software. Results: In 237 patients, planar imaging of 142 cases matched the final diagnosis in which 72 had benign lesions and 70 had bone metastases. The definite coincidence rate was 95.30% (142/149). SPECT/CT imaging of 224 cases matched the final diagnosis in which 104 had benign lesions and 120 cases diagnosed as bone metastases. The coincidence and definite coincidence rates were 94.51% (224/237), and 99.48% (192/193). Difference in the definite coincidence rate between planar and SPECT/CT imaging was statistically significant (χ 2 = 5.37, P=0.024). Conclusion: SPECT/CT imaging is valuable for accurate localization of osseous pathology and for improvement of diagnosing bone metastasis. (authors)

  5. Scientific value of systematic reviews: survey of editors of core clinical journals.

    Directory of Open Access Journals (Sweden)

    Joerg J Meerpohl

    Full Text Available BACKGROUND: Synthesizing research evidence using systematic and rigorous methods has become a key feature of evidence-based medicine and knowledge translation. Systematic reviews (SRs may or may not include a meta-analysis depending on the suitability of available data. They are often being criticised as 'secondary research' and denied the status of original research. Scientific journals play an important role in the publication process. How they appraise a given type of research influences the status of that research in the scientific community. We investigated the attitudes of editors of core clinical journals towards SRs and their value for publication. METHODS: We identified the 118 journals labelled as "core clinical journals" by the National Library of Medicine, USA in April 2009. The journals' editors were surveyed by email in 2009 and asked whether they considered SRs as original research projects; whether they published SRs; and for which section of the journal they would consider a SR manuscript. RESULTS: The editors of 65 journals (55% responded. Most respondents considered SRs to be original research (71% and almost all journals (93% published SRs. Several editors regarded the use of Cochrane methodology or a meta-analysis as quality criteria; for some respondents these criteria were premises for the consideration of SRs as original research. Journals placed SRs in various sections such as "Review" or "Feature article". Characterization of non-responding journals showed that about two thirds do publish systematic reviews. DISCUSSION: Currently, the editors of most core clinical journals consider SRs original research. Our findings are limited by a non-responder rate of 45%. Individual comments suggest that this is a grey area and attitudes differ widely. A debate about the definition of 'original research' in the context of SRs is warranted.

  6. Clinical value of pre-operative embolization of maxillary artery for nasopharyngeal angiofibroma

    International Nuclear Information System (INIS)

    Zhu Wenke; Shan Hong; Zhu Kangshun; Jiang Zabo; Guan Shouhai; Huang Mingsheng; Li Zhengran; Shen Xinying

    2004-01-01

    Objective: To assess the clinical value of pre-operative embolization for nasopharyngeal angiofibroma. Methods: 13 patients with nasopharyngeal angiofibroma confirmed by surgery and biopsy were retrospectively analysed. Bilateral carotid artery angiography was performed for demonstration of the arterial supply of tumor. According to the size and different caliber of arteries, embolization were separately undertaken by different types of coil via 4.1 or 5F Head-Hunter catheter. The embolization efficacy, embolization was evaluated by amount of blood loss. Results: After coil embolization, no complication happened ranging 1-4 days (mean 2 days) in all 13 patients and then all the tumor masses were totally resected with mean blood loss of (584.6 ± 379.4) ml (range 250-1500 ml). Conclusions: Preoperative coils embolization is safe, reliable with less complication especially for reducing intraoperative blood loss and promoting the prognosis. (authors)

  7. Histological evaluation of the human testis--approaches to optimizing the clinical value of the assessment

    DEFF Research Database (Denmark)

    McLachlan, R I; Rajpert-De Meyts, E; Hoei-Hansen, C E

    2007-01-01

    on genotype-phenotype relationships. The rising incidence of testis cancer and carcinoma in situ (CIS), especially in infertile populations, requires that every effort be made for its early detection. We provide a systematic approach to the histological classification of spermatogenic disorders and detection...... within the hypospermatogenesis classification, that helps account for reported success of TESE. We propose a new diagnosis code for testicular biopsies that addresses the needs of ART clinicians and allows data storage and retrieval of value in clinical practice and research....

  8. The diagnostic value of the fibrinogen/fibrin fragment E antigen assay in clinically suspected deep vein thrombosis

    International Nuclear Information System (INIS)

    Zielinsky, A.; Hirsh, J.; Straumanis, G.; Carter, C.J.; Gent, M.; Sackett, D.L.; Hull, R.; Kelton, J.G.; Powers, P.; Turpie, A.G.

    1982-01-01

    We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice

  9. The diagnostic value of the fibrinogen/fibrin fragment E antigen assay in clinically suspected deep vein thrombosis

    International Nuclear Information System (INIS)

    Zielinsky, A.; Hirsh, J.; Straumanis, G.; Carter, C.J.; Gent, M.; Sackett, D.L.; Hull, R.; Kelton, J.G.; Powers, P.

    1982-01-01

    We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice

  10. Survival and cardiovascular events after coarctation-repair in long-term follow-up (COAFU): Predictive value of clinical variables.

    Science.gov (United States)

    Bambul Heck, P; Pabst von Ohain, J; Kaemmerer, H; Ewert, P; Hager, A

    2017-02-01

    Long-term sequelae and events after coarctation repair are well described. However, the predictive value of variables from clinical follow-up investigation for late events and survival has rarely been investigated. All patients who participated in the prospective cross-sectional COALA Study in 2000 with a structural clinical investigation including blood pressure measurement and symptom-limited exercise test were contacted for reevaluation of survival, current clinical status and major cardiovascular events. Of 273 eligible patients, 209 were available for follow-up. Nine patients had died at a median age of 46years (range 30-64years), five of them due to cardiovascular complications. Late mortality after surgical intervention was 5.7% with a median age of 41years (range 16-64years). Twenty-five patients had a major cardiovascular event: 12 had procedures at the aortic valve or aortic arch, 8 had procedures for restenosis, 2 had endocarditis, 2 had a cerebrovascular insult and 1 an aortic dissection. The presence of bicuspid aortic valve (p=0.009), brachial-ankle blood pressure gradient >20mmHg (p<0.001) and reduced left ventricular function (p=0.002) correlated with major cardiovascular events. Surgical correction of coarctation of the aorta shows fairly low mortality in the long-term follow-up. Late morbidities include recoarctation, but also the consequences of the hemodynamics produced by a congenital bicuspid aortic valve, presence of which is predictive for aortic valve procedures: however the predictive value of clinical variables is limited. Copyright © 2016. Published by Elsevier Ireland Ltd.

  11. Diagnostic and prognostic value of asphyxia, Sarnat's clinical classification, and CT-scan in perinatal brain damage

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Toshihide; Wakita, Yoshiharu; Kubonishi, Sakae; Yoshikawa, Seishi (Kochi Prefectural Central Hospital (Japan)); Ito, Toshiyuki; Okada, Yasusuke

    1990-11-01

    A retrospective review was made of 145 babies, excluding those with congenital heart disease or chromosome aberration, admitted for CT scanning. The study was done to determine the diagnostic and prognostic value of CT findings, as well as the presence of asphyxia and the clinical stage based on the Sarnat's classification, in perinatal brain damage. The patients had a minimum follow up of 2 years for the evaluation of neurologic manifestations, such as cerebral palsy, epilepsy and mental retardation. Among babies weighing 2,000 g or more at birth, neonatal asphyxia was significantly correlated with neurologic prognosis. In addition, both clinical stages and CT findings were significantly correlated with neurologic prognosis, irrespective of birth weight. The correlation between clinical stages and CT findings was significant, irrespective of body weight, however, a significant correlation between clinical stages and neonatal asphyxia was restricted to those weighing 2,000 g or more. These findings suggest that the presence of asphyxia, clinical stages and CT findings are complementary in the diagnosis and prognosis evaluation of perinatal brain damage. (N.K.).

  12. Study of biological effects of accelerated heavy ions irradiation on rices: Pt. 1

    International Nuclear Information System (INIS)

    Liu Zhensheng; Qiu Quanfa; Huang Wenzhong; Mei Mantong; Yang, T.C.H.

    1991-01-01

    The dried rice seeds were irradiated with accelerated 56 Fe and 40 Ar ion beams or 60 Co γ-rays at various doses. The irradiation effects on seeding growth as well as micronuclei and chronosome aberration induction were observed. The results indicated that the seeding height raduction, frequency of micronucleated cells and frequency of chromosome aberrations all appeared to dose dependent for these three types of rediation. The RBE value for seeding height reduction, determined at fifity percent of hight inhibition level, was found to be about 6.3, 1.9 and 1 for 56 Fe, 40 Ar and 60 Co γ-ray respectively. However, the RBE values for the frequency of micronucleated cells were about 11, 4 and 1 for 56 Fe and 40 Ar particles and 60 Co γ-ray. It appeared that the effectiveness of high LET radiation in inducing biological effects at the first generation was higler than that of low LET radiation, especially in inducing the micronuclei formation

  13. Mutation induction and neoplastic transformation in human and human-hamster hybrid cells: dependence on photon energy and modulation in the low-dose range

    Energy Technology Data Exchange (ETDEWEB)

    Frankenberg, D.; Frankenberg-Schwager, M.; Garg, I.; Pralle, E. [Abt. Klin. Strahlenbiologie und Klin. Strahlenphysik, Universitaet Goettingen, Goettingen (Germany); Uthe, D.; Greve, B.; Severin, E.; Goehde, W. [Institut fuer Strahlenbiologie, Universitaet Muenster, Munster (Germany)

    2002-09-01

    Mutation induction in the HPRT gene of human fibroblasts after irradiation with mammography-like 29 kVp or 200 kVp x-rays shows radiohypersensitivity for doses smaller than {approx}0.5 Gy. Similarly, mutation induction in the CD 59 gene on human chromosome 11 in A{sub L} cells shows radiohypersensitivity for doses smaller than {approx}0.5 Gy after exposure to 200 kVp x-rays, but not after irradiation with low-filtered 30 kVp x-rays. The RBE values of 29 and 30 kVp x-rays relative to 200 kVp x-rays are strongly dose dependent. For neoplastic transformation of human hybrid (CGL1) cells after irradiation with 29 or 200 kVp x-rays or {sup 60}Co gamma rays a linear-quadratic dose relationship was observed with RBE values of approximately four and eight for mammography relative to 200 kVp x-rays and {sup 60}Co gamma rays, respectively. (author)

  14. Value Set Authority Center

    Data.gov (United States)

    U.S. Department of Health & Human Services — The VSAC provides downloadable access to all official versions of vocabulary value sets contained in the 2014 Clinical Quality Measures (CQMs). Each value set...

  15. SU-E-T-549: Modeling Relative Biological Effectiveness of Protons for Radiation Induced Brain Necrosis

    International Nuclear Information System (INIS)

    Mirkovic, D; Peeler, C; Grosshans, D; Titt, U; Taleei, R; Mohan, R

    2015-01-01

    Purpose: To develop a model of the relative biological effectiveness (RBE) of protons as a function of dose and linear energy transfer (LET) for induction of brain necrosis using clinical data. Methods: In this study, treatment planning information was exported from a clinical treatment planning system (TPS) and used to construct a detailed Monte Carlo model of the patient and the beam delivery system. The physical proton dose and LET were computed in each voxel of the patient volume using Monte Carlo particle transport. A follow-up magnetic resonance imaging (MRI) study registered to the treatment planning CT was used to determine the region of the necrosis in the brain volume. Both, the whole brain and the necrosis volumes were segmented from the computed tomography (CT) dataset using the contours drawn by a physician and the corresponding voxels were binned with respect to dose and LET. The brain necrosis probability was computed as a function of dose and LET by dividing the total volume of all necrosis voxels with a given dose and LET with the corresponding total brain volume resulting in a set of NTCP-like curves (probability as a function of dose parameterized by LET). Results: The resulting model shows dependence on both dose and LET indicating the weakness of the constant RBE model for describing the brain toxicity. To the best of our knowledge the constant RBE model is currently used in all clinical applications which may Result in increased rate of brain toxicities in patients treated with protons. Conclusion: Further studies are needed to develop more accurate brain toxicity models for patients treated with protons and other heavy ions

  16. Cellular- and micro-dosimetry of heterogeneously distributed tritium.

    Science.gov (United States)

    Chao, Tsi-Chian; Wang, Chun-Ching; Li, Junli; Li, Chunyan; Tung, Chuan-Jong

    2012-01-01

    The assessment of radiotoxicity for heterogeneously distributed tritium should be based on the subcellular dose and relative biological effectiveness (RBE) for cell nucleus. In the present work, geometry-dependent absorbed dose and RBE were calculated using Monte Carlo codes for tritium in the cell, cell surface, cytoplasm, or cell nucleus. Penelope (PENetration and Energy LOss of Positrins and Electrons) code was used to calculate the geometry-dependent absorbed dose, lineal energy, and electron fluence spectrum. RBE for the intestinal crypt regeneration was calculated using a lineal energy-dependent biological weighting function. RBE for the induction of DNA double strand breaks was estimated using a nucleotide-level map for clustered DNA lesions of the Monte Carlo damage simulation (MCDS) code. For a typical cell of 10 μm radius and 5 μm nuclear radius, tritium in the cell nucleus resulted in much higher RBE-weighted absorbed dose than tritium distributed uniformly. Conversely, tritium distributed on the cell surface led to trivial RBE-weighted absorbed dose due to irradiation geometry and great attenuation of beta particles in the cytoplasm. For tritium uniformly distributed in the cell, the RBE-weighted absorbed dose was larger compared to tritium uniformly distributed in the tissue. Cellular- and micro-dosimetry models were developed for the assessment of heterogeneously distributed tritium.

  17. Clinical value of Tl per rectum scintigraphy in the work-up of patients with alcoholic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Urbain, D.; Reding, P.; Georges, B.; Thys, O.; Ham, H.R.

    1986-09-01

    The clinical value of thallium 201 per rectum scintigraphy in the work-up of patients with alcoholic liver disease was evaluated using data obtained in 104 patients. The 25th min ratio of heart to liver activities was used as an index of portal systemic shunting. This ratio was found to be normal in alcoholic patients with normal liver biopsy and also in those presenting only steatosis. It was slightly higher in patients with liver fibrosis and significantly higher values were observed in patients with liver cirrhosis. High values of the ratio were associated with a higher risk of portal systemic encephalopathy and/or gastrointestinal bleeding. The prognostic value of the test was supported by the fact that good correlations were observed between the ratio and widely accepted prognostic scores such as the Child score or the Orrego index. Moreover, high ratios were associated with an increased mortality risk at one year. We conclude that this simple test is interesting in the screening of cirrhotics at risk of encephalopathy, gastrointestinal hemorrhage, or early death.

  18. Relative biological effectiveness of protons and heavy particles

    International Nuclear Information System (INIS)

    Vyglenov, A.; Fedorenko, B.; Kabachenko, A.

    1986-01-01

    The genetic effectiveness was studied of protons (9 GeB/nuclon, 0,72 Gy/min), α-particles (4 GeB/nuclon, 0,9 Gy/min) and carbon ions (4 GeB/nuclon 0,36 Gy/min). The translocation yield in mouse spermatogonia was used as indicator of radiation-induced genetic injury. Reciprocal translocation were registered six months after the irradiation on spermatocytes in diakinesmetaphase I. Comparison was made with gamma-irradiated animals from 60 Co source with dose rate 1,44 Gy/min. The relative biological effectiveness (RBE) was determined by comparing the regression coefficients from the linear dose translocation yield dependency. The values of the RBE coefficients were 0.8, 0.9 and 1.2, accordingly for protons, α-particles and carbon ions

  19. The perceived value of clinical pharmacy service provision by pharmacists and physicians: an initial assessment of family medicine and internal medicine providers.

    Science.gov (United States)

    Wietholter, Jon P; Ponte, Charles D; Long, Dustin M

    2017-10-01

    Few publications have addressed the perceptions of pharmacists and physicians regarding the value of clinical pharmacist services. A survey-based study was conducted to determine whether Internal Medicine (IM) and Family Medicine (FM) pharmacists and physicians differed in their attitudes regarding the benefits of collaboration in an acute care setting. The primary objective was to evaluate perceived differences regarding self-assessment of value between IM and FM pharmacists. The secondary objective was to evaluate perceived differences of clinical pharmacist benefit between IM and FM physicians. An eight-item questionnaire assessed the attitudes and beliefs of pharmacists and physicians regarding the value of clinical pharmacy services. Surveys were emailed and participants marked their responses using a 7-point Likert scale for each item. Demographic data and overall comments were collected from each participant. Overall, 167 surveys were completed. When comparing cumulative physician and pharmacist responses, none of the eight questions showed significant differences. Statistically significant differences were noted when comparing IM and FM clinical pharmacists on five of the eight survey items; for each of these items, FM pharmacists had more favourable perceptions than their IM counterparts. No statistically significant differences were noted when comparing responses of IM and FM physicians. This study found that FM pharmacists perceived a greater benefit regarding participation in inpatient acute care rounds when compared to their IM pharmacist counterparts. Future studies are necessary to determine if other medical specialties' perceptions of clinical pharmacy provision differ from our findings and to evaluate the rationale behind specific attitudes and behaviours. © 2016 Royal Pharmaceutical Society.

  20. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Georg, Dietmar, E-mail: Dietmar.Georg@akhwien.at [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hopfgartner, Johannes [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Gòra, Joanna [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kuess, Peter [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kragl, Gabriele [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Berger, Daniel [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hegazy, Neamat [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Goldner, Gregor; Georg, Petra [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria)

    2014-03-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ({sup 192}Ir) and LDR-BT ({sup 125}I) were D{sub 90%} ≥34 Gy in 8.5 Gy per fraction and D{sub 90%} ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D{sub mean} around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques

  1. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Georg, Dietmar; Hopfgartner, Johannes; Gòra, Joanna; Kuess, Peter; Kragl, Gabriele; Berger, Daniel; Hegazy, Neamat; Goldner, Gregor; Georg, Petra

    2014-01-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ( 192 Ir) and LDR-BT ( 125 I) were D 90% ≥34 Gy in 8.5 Gy per fraction and D 90% ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D mean around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques were clearly superior in

  2. 20neon ion- and x-ray-induced mammary carcinogenesis in female rats

    International Nuclear Information System (INIS)

    Shellabarger, C.J.; Baum, J.W.; Holtzman, S.; Stone, J.P.

    1983-01-01

    One of the proposed uses of heavy ion irradiation is to image lesions of the human female breast. The rat model system was chosen to assess the carcinogenic potential of heavy ion irradiation in the belief that data obtained from rat studies would have a qualitatively predictive value for the human female. Accordingly, female rats were exposed to 20 Ne ions at the BEVALAC and studied for the development of mammary neoplasia for 312 +- 2 days at Brookhaven along with rats exposed concurrently to x-irradiation or to no irradiation. As the dose of either type of radiation was increased the percent of rats with mammary adenocarcinomas, and the percent of rats with mammary fibroadenomas, tended to increase. At a prevalence of 20%, the RBE for 20 Neon ions for mammary adenocarcinomas was estimated to be larger than 5 and for mammary fibroadenomas the RBE was estimated to be less than 2. No conclusion was reached concerning whether or not the RBE might vary with dose. We suggest that 20 Ne ions do have a carcinogenic potential for rat mammary tissue and that this carcinogenic potential is likely to be greater than for x-irradiation. (DT)

  3. DNA damage produced by exposure of supercoiled plasmid DNA to high- and low-LET ionizing radiation: Effects of hydroxyl radical quenchers. DNA breakage, neutrons, OH radicals

    International Nuclear Information System (INIS)

    Peak, J.G.; Ito, T.; Peak, M.J.; Robb, F.T.

    1994-01-01

    A supercoiled plasmid of 7300 base pairs was isolated and exposed in an aqueous environment to 60 Co γ rays and JANUS 0.85 MeV fission-spectrum neutrons. Dose responses for the production of single-strand breaks (SSBs), double-strand breaks (DSBs) and alkali-labile sites (ALSs) were compared with computations made from the conversion of the supercoil to its relaxed and linear forms. The relative biological effectiveness (RBE) for production of SSBs and DSBs was similar to that previously measured in the cellular environment. The RBE for destruction of genetic transforming activity of M13 viral DNA followed that for DNA damage. This is in contrast to the situation for biological effects such as lethality, mutagenesis, and cellular transformation measured in mammalian cells, where the RBE values are reversed. The role of hydroxyl (OH) radical in DNA damage induction by neutrons was investigated by exposure of plasmid in the presence of known quenchers of this species. Of four quenchers tested, all were able to reduce the yields of both SSBs and DSBs. These findings are consistent with a model for SSB and DSB induction by high linear energy transfer that involves OH radical mediation

  4. Clinical utility of high b-value diffusion-weighted magnetic resonance imaging in post-resuscitative encephalopathy

    International Nuclear Information System (INIS)

    Kano, Hitoshi; Danjou, Wataru; Yamazaki, Kei

    2002-01-01

    It is very important to estimate brain functional capacity immediately after successful cardiopulmonary resuscitation (CPR) to determine subsequent treatment strategy and to elucidate the pathophysiology of patients with post-resuscitative encephalopathy. However, computed tomography scanning, electric encephalography and conventional magnetic resonance imaging do not contribute significantly to the assessment of brain functions immediately after CPR. Recently, diffusion-weighted magnetic resonance imaging (DW-MRI) has been applied to the patients with post-resuscitative encephalopathy. However, no papers have described serial clinical and repeated DW-MRI studies of patients during the acute phase of post-resuscitative encephalopathy. Moreover, in some cases, high signal intensity in the cortex after CPR is indistinguishable from normal cortex. Thus, we tried to apply high b-value DW-MRI to estimate the brain function of patients with post-resuscitative encephalopathy. This study was performed on 11 patients with post-resuscitative encephalopathy and 5 healthy volunteers as controls. DW-MRI was performed using GYROSCAN 1.5 Tesla MR imager (Philips) with single-shot echo-planner imaging sequences performed 3 times, first within 24 hours after CPR, second between day 3 to 6, and third more than 7 days after CPR. And we tested the usefulness of DW-MRI at 800, 1000, 1500, 2000 and 3000 in b value. Five patients survived, one fully recovered and four remained in a vegetative state. The other six died with clinical brain death. The first DW-MRI revealed in high signal intensity in the frontal and the parietal lobes in all patients who eventually progressed to a vegetative state or brain death. This result was much more wide-spread in the latter patients, while it was never seen in the patients who recovered fully. The high signal intensity areas increased in follow-up DW-MRI studies. The signal intensity remained high in some parts, while it decreased in other parts with

  5. Clinical utility of high b-value diffusion-weighted magnetic resonance imaging in post-resuscitative encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kano, Hitoshi; Danjou, Wataru; Yamazaki, Kei [Sapporo City General Hospital (Japan)] (and others)

    2002-03-01

    It is very important to estimate brain functional capacity immediately after successful cardiopulmonary resuscitation (CPR) to determine subsequent treatment strategy and to elucidate the pathophysiology of patients with post-resuscitative encephalopathy. However, computed tomography scanning, electric encephalography and conventional magnetic resonance imaging do not contribute significantly to the assessment of brain functions immediately after CPR. Recently, diffusion-weighted magnetic resonance imaging (DW-MRI) has been applied to the patients with post-resuscitative encephalopathy. However, no papers have described serial clinical and repeated DW-MRI studies of patients during the acute phase of post-resuscitative encephalopathy. Moreover, in some cases, high signal intensity in the cortex after CPR is indistinguishable from normal cortex. Thus, we tried to apply high b-value DW-MRI to estimate the brain function of patients with post-resuscitative encephalopathy. This study was performed on 11 patients with post-resuscitative encephalopathy and 5 healthy volunteers as controls. DW-MRI was performed using GYROSCAN 1.5 Tesla MR imager (Philips) with single-shot echo-planner imaging sequences performed 3 times, first within 24 hours after CPR, second between day 3 to 6, and third more than 7 days after CPR. And we tested the usefulness of DW-MRI at 800, 1000, 1500, 2000 and 3000 in b value. Five patients survived, one fully recovered and four remained in a vegetative state. The other six died with clinical brain death. The first DW-MRI revealed in high signal intensity in the frontal and the parietal lobes in all patients who eventually progressed to a vegetative state or brain death. This result was much more wide-spread in the latter patients, while it was never seen in the patients who recovered fully. The high signal intensity areas increased in follow-up DW-MRI studies. The signal intensity remained high in some parts, while it decreased in other parts with

  6. Clinical value of FDG hybrid-PET in staging and restaging of malignant lymphoma. Compared with conventional diagnostic methods

    International Nuclear Information System (INIS)

    Pichler, R.; Maschek, W.; Hatzl-Griesenhofer, M.; Huber, H.; Wimmer, G.; Wahl, G.; Fridrik, M.

    2000-01-01

    Aim of the present retrospective study was to validate the clinical value of F-18-FDG PET imaging in lymphoma patients with a dual head camera modified for coincidence detection. Staging before and after oncological treatment was compared with a conservative diagnostic approach. Methods: 48 patients (28 non-Hodgkin lymphoma, 20 Hodgkin's disease) received FDG-Hybrid-PET scans. Pretherapeutic staging was realized in 28 patients, 9 of them had control studies after they had completed therapy. Totally 29 persons were examined for posttherapeutic restaging. Computed tomography imaging and lymph node sonography was performed in all cases. Results were validated by clinical follow-up, in three cases a recidive was proven by biopsy. Results: CT and ultrasound detected 77 lesions in 28 patients compared with 100 visualized by PET, but this difference in pretherapeutic staging did not reach significance at p>0.05 by Fisher's t-test. Hybrid-PET obtained a sensitivity of 93%, a specifity of 79%, a positive of 82% and a negative predictive value of 92% for detection of residual disease. The values for CT+US were 87%, 64%, 72% and 88% respectively. Conclusion: FDG Hybrid-PET is as or even more accurate than standard morphologic diagnostic methods for prestaging in malignant lymphoma. Additionally, there is a substancial benefit for therapy monitoring of residual disease using coincidence detection PET with a 3/4-inch crystal gamma camera. (orig.) [de

  7. Value-driven ERM: making ERM an engine for simultaneous value creation and value protection.

    Science.gov (United States)

    Celona, John; Driver, Jeffrey; Hall, Edward

    2011-01-01

    Enterprise risk management (ERM) began as an effort to integrate the historically disparate silos of risk management in organizations. More recently, as recognition has grown of the need to cover the upside risks in value creation (financial and otherwise), organizations and practitioners have been searching for the means to do this. Existing tools such as heat maps and risk registers are not adequate for this task. Instead, a conceptually new value-driven framework is needed to realize the promise of enterprise-wide coverage of all risks, for both value protection and value creation. The methodology of decision analysis provides the means of capturing systemic, correlated, and value-creation risks on the same basis as value protection risks and has been integrated into the value-driven approach to ERM described in this article. Stanford Hospital and Clinics Risk Consulting and Strategic Decisions Group have been working to apply this value-driven ERM at Stanford University Medical Center. © 2011 American Society for Healthcare Risk Management of the American Hospital Association.

  8. [The clinical value of urinary antigen detection of Legionella pneumonia].

    Science.gov (United States)

    Jiang, Luxi; Chen, Yu; Xia, Shuyue; Ma, Jiangwei; Zhao, Hongwen; Lu, Ye; Tao, Sixu; Zhao, Li

    2015-01-01

    To investigate the clinical value of urinary antigen detection of Legionella, and to describe the clinical characteristics of Legionella pneumonia. Patients with suspected Legionella pneumonia were enrolled from the Respiratory departments of 3 tertiary hospitals in Shenyang during May 2011 to November 2013. Urinary Legionella antigen was detected for all the enrolled patients. Bacterial culture, polymerase chain reaction (PCR) for Legionella, and double Legionella antibody detection in sera were performed for each patient whose urinary antigen was positive. Patients confirmed to have Legionella pneumonia were pooled and analyzed. Totally 13 cases presenting with pneumonia were positive for Legionella by the urinary antigen method, and in one of them Legionella strain was isolated from the secretion of lower respiratory tract. PCR detection was performed in 8 patients, and 4 of them were positive. Legionella antibody detection was performed in 12 patients, and 7 of them were positive. Nine patients had a history of exposure to Legionella high-risk environments. The characteristics of the cases with Legionella pneumonia were as follows: characteristic orange sputum in 4 patients, digestive symptoms in 6, neurologic disorders in 8, hyponatremia in 10, hypoxia with oxygenation index 130) in 8 patients . Chest CT scan showed bilateral involvement in 6, ground-glass opacity combined with consolidation in 11, and moderate pleural effusion in 11 patients. Cavity and reversed halo sign were found in one case, respectively. All of the patients received fluoroquinolone treatment, and 11 patients recovered completely while 2 died of multiple organ dysfunction syndrome, one of them was complicated with secondary infection. Detection of urinary antigen of Legionella is very useful in the diagnosis of Legionella pneumonia. Attention should be paid to exposure history to the high-risk environments and multiple organ impairment when Legionella infection is suspected. Orange sputum

  9. Added Diagnostic Value of 11C-PiB-PET in Memory Clinic Patients with Uncertain Diagnosis

    Directory of Open Access Journals (Sweden)

    K.S. Frederiksen

    2012-12-01

    Full Text Available Introduction: The added diagnostic value of 11C-PiB-PET for the assessment of the accumulation of cortical beta-amyloid in memory clinic patients with uncertain diagnosis remains undetermined. Methods: All patients who underwent PiB-PET at the Copenhagen Memory Clinic between March 2008 and November 2011 were included in this uncontrolled, retrospective study. The standard diagnostic evaluation program included physical and neurological examination, cognitive and functional assessment, a cranial CT or MRI, functional imaging and cerebrospinal fluid sampling. Based on anonymized case reports, three experienced clinicians reached a consensus diagnosis and rated their confidence in the diagnosis before and after disclosure of PiB-PET ratings. PiB-PET scans were rated as either positive or negative. Results: A total of 57 patients (17 females, 30 males; age 65.7 years, range 44.2–82.6 were included in the study. Twenty-seven had a positive PiB-PET scan. At the first diagnostic evaluation, 16 patients were given a clinical Alheimer’s disease diagnosis (14 PiB positive. Of the 57 patients, 13 (23% were diagnostically reclassified after PiB-PET ratings were disclosed. The clinicians’ overall confidence in their diagnosis increased in 28 (49% patients. Conclusion: PiB-PET adds to the specialist clinical evaluation and other supplemental diagnostic investigations in the diagnostic classification of patients with uncertain diagnosis in a specialized memory clinic.

  10. Carbon-ion scanning lung treatment planning with respiratory-gated phase-controlled rescanning: simulation study using 4-dimensional CT data.

    Science.gov (United States)

    Takahashi, Wataru; Mori, Shinichiro; Nakajima, Mio; Yamamoto, Naoyoshi; Inaniwa, Taku; Furukawa, Takuji; Shirai, Toshiyuki; Noda, Koji; Nakagawa, Keiichi; Kamada, Tadashi

    2014-11-11

    To moving lung tumors, we applied a respiratory-gated strategy to carbon-ion pencil beam scanning with multiple phase-controlled rescanning (PCR). In this simulation study, we quantitatively evaluated dose distributions based on 4-dimensional CT (4DCT) treatment planning. Volumetric 4DCTs were acquired for 14 patients with lung tumors. Gross tumor volume, clinical target volume (CTV) and organs at risk (OARs) were delineated. Field-specific target volumes (FTVs) were calculated, and 48Gy(RBE) in a single fraction was prescribed to the FTVs delivered from four beam angles. The dose assessment metrics were quantified by changing the number of PCR and the results for the ungated and gated scenarios were then compared. For the ungated strategy, the mean dose delivered to 95% of the volume of the CTV (CTV-D95) was in average 45.3 ± 0.9 Gy(RBE) even with a single rescanning (1 × PCR). Using 4 × PCR or more achieved adequate target coverage (CTV-D95 = 46.6 ± 0.3 Gy(RBE) for ungated 4 × PCR) and excellent dose homogeneity (homogeneity index =1.0 ± 0.2% for ungated 4 × PCR). Applying respiratory gating, percentage of lung receiving at least 20 Gy(RBE) (lung-V20) and heart maximal dose, averaged over all patients, significantly decreased by 12% (p lung tumors without gating. The use of a respiratory-gated strategy in combination with PCR reduced excessive doses to OARs.

  11. Study on clinical value of determination of plasma brain natriuretic peptide levels in patients with chronic congestive heart failure

    International Nuclear Information System (INIS)

    Chen Jianxiong; Li Zhuocheng; Tu Hong

    2010-01-01

    Objective: To evaluate the clinical value of determination of plasma brain natriuretic peptide (BNP) levels in patients with chronic congestive heart failure(CHF). Methods: The levels of plasma BNP were measured with fluorescence immunoassay in 341 patients with chronic CHF and 55 controls. Left ventricular ejection fraction (LVEF), left ventricular end systolic diameter (LVESD) and left ventricular end diastolic diameter (LVEDD) were determined with color doppler ultrasonography in CHF patients. Results: Plasma levels of BNP were significantly increased in patients with CHF as compared with those in controls (P<0.01). There were also significant differences in plasma levels of CHF patients of different clinical stages (P<0.01). There was obvious correlation between plasma levels of BNP and the values of LVEF, LVESD and LVEDD (r was-0.62, +0.54 and +0.60 respectively, P<0.01). Conclusion: Plasma level of BNP is a sensitive indicator for assessment of ventricle function in CHF patients. (authors)

  12. Clinically healthy overweight and obese dogs differ from lean controls in select CBC and serum biochemistry values.

    Science.gov (United States)

    Radakovich, Lauren B; Truelove, Matthew P; Pannone, Stephen C; Olver, Christine S; Santangelo, Kelly S

    2017-06-01

    Obesity is a global disease, affecting nearly half a billion people. Unfortunately, this trend is mirrored in our canine population. As obesity is a complex inflammatory disease, there is a need to determine whether routine medical screening tests may indicate, or be influenced by, its presence. The objective of the current study was to determine if significant differences exist between CBC and biochemical profile values from control vs overweight/obese, client-owned dogs considered clinically healthy. Dogs presented for routine health examinations, including minor dental or elective surgical procedures, were retrospectively identified from a hospital population. Animals were allocated to 2 categories based on body condition score (BCS), and data were analyzed by Mann-Whitney nonparametric analysis with statistical significance at a P ≤ .05. After exclusions, 116 dogs were assigned to the overweight/obese group (BCS ≥ 7) and 240 dogs to the control group (BCS = 4-6). Overweight/obese dogs had higher total leukocyte counts and higher plasma protein and globulin concentrations. Other differences were attributed to decreased serum water fraction (increased sodium, albumin, calcium, and anion gap) in the overweight/obese group. Interestingly, chloride concentration was decreased (in the face of increased sodium) in the obese group. There is CBC and biochemical evidence to support the concern that obesity influences laboratory values, even in dogs considered clinically healthy. Prospective studies aimed at characterizing these changes are needed to provide insight into the connection between obesity and its comorbidities. © 2017 American Society for Veterinary Clinical Pathology.

  13. Human cytogenetic dosimetry: a dose-response relationship for alpha particle radiation from 241Am

    International Nuclear Information System (INIS)

    DuFrain, R.J.; Littlefield, L.G.; Joiner, E.E.; Frome, E.L.

    1979-01-01

    Cytogenetic dosimetry estimates to guide treatment of persons internally contaminated with transuranic elements have not previously been possible because appropriate in vitro dose-response curves specifically for alpha particle irradiation of human lymphocytes do not exist. Using well-controlled cytogenetic methods for human lymphocyte culture, an experimentally derived dose-response curve for 241 Am alpha particle (5.49 and 5.44 MeV) radiation of G 0 lymphocytes was generated. Cells were exposed to 43.8, 87.7, 175.3 or 350.6 nCi/ml 241 Am for 1.7 hr giving doses of 0.85, 1.71, 3.42 or 6.84 rad. Based on dicentric chromosome yield, the linear dose-response equation is Y = 4.90(+-0.42) x 10 -2 X, with Y given as dicentrics per cell and X as dose in rads. The study also shows that the two-break asymmetrical exchanges in cells damaged by alpha particle radiation are overdispersed when compared to a Poisson distribution. An example is presented to show how the derived dose-response equation can be used to estimate the radiation dose for a person internally contaminated with an actinide. An experimentally derived RBE value of 118 at 0.85 rad is calculated for the efficiency of 241 Am alpha particle induction of dicentric chromosomes in human G 0 lymphocytes as compared with the efficiency of 60 Co gamma radiation. The maximum theoretical value for the RBE for cytogenetic damage from alpha irradiation was determined to be 278 at 0.1 rad or less which is in marked contrast to previously reported RBE values of approx. 20. (author)

  14. Clinical value of patient-specific three-dimensional printing of congenital heart disease: Quantitative and qualitative assessments

    Science.gov (United States)

    Lau, Ivan Wen Wen; Liu, Dongting; Xu, Lei; Fan, Zhanming

    2018-01-01

    Objective Current diagnostic assessment tools remain suboptimal in demonstrating complex morphology of congenital heart disease (CHD). This limitation has posed several challenges in preoperative planning, communication in medical practice, and medical education. This study aims to investigate the dimensional accuracy and the clinical value of 3D printed model of CHD in the above three areas. Methods Using cardiac computed tomography angiography (CCTA) data, a patient-specific 3D model of a 20-month-old boy with double outlet right ventricle was printed in Tango Plus material. Pearson correlation coefficient was used to evaluate correlation of the quantitative measurements taken at analogous anatomical locations between the CCTA images pre- and post-3D printing. Qualitative analysis was conducted by distributing surveys to six health professionals (two radiologists, two cardiologists and two cardiac surgeons) and three medical academics to assess the clinical value of the 3D printed model in these three areas. Results Excellent correlation (r = 0.99) was noted in the measurements between CCTA and 3D printed model, with a mean difference of 0.23 mm. Four out of six health professionals found the model to be useful in facilitating preoperative planning, while all of them thought that the model would be invaluable in enhancing patient-doctor communication. All three medical academics found the model to be helpful in teaching, and thought that the students will be able to learn the pathology quicker with better understanding. Conclusion The complex cardiac anatomy can be accurately replicated in flexible material using 3D printing technology. 3D printed heart models could serve as an excellent tool in facilitating preoperative planning, communication in medical practice, and medical education, although further studies with inclusion of more clinical cases are needed. PMID:29561912

  15. The clinical value of pulmonary perfusion imaging complicated with pulmonary embolism in children of nephrotic syndrome

    International Nuclear Information System (INIS)

    Lin Jun; Chen Ning; Miao Weibing; Peng Jiequan; Jiang Zhihong; Wu Jing

    2001-01-01

    To investigate the clinical features of complicated with pulmonary embolism nephrotic syndrome in children. 99m Tc-MAA pulmonary perfusion imaging was performed on 30 nephrotic syndrome in children with elevated plasma D-dimer. Results shown that 14 of 30 patients were found to have pulmonary embolism (46.7%). Pulmonary perfusion imaging showed an involvement of 1 pulmonary segment in 3 cases, 2 segments in 2 cases and over 3 segments in other 9 cases. Among them, there were 7 segments involved in one case. After two weeks of heparin anti-coagulative therapy, most cases showed a recovery. The result of this study suggested that pulmonary embolism is a common complication of nephrotic syndrome. Pulmonary perfusion imaging is simple, effective and accurate method for the diagnosis of pulmonary embolism, and it also can help to assess the value of clinical therapy

  16. Medical device innovation and the value analysis process.

    Science.gov (United States)

    Krantz, Heidi; Strain, Barbara; Torzewski, Jane

    2017-09-01

    Heidi A. Krantz, RN, BSN is the Director of Value Analysis at Johns Hopkins Bayview Medical Center in the Johns Hopkins Health System. Barbara Strain, MA, CVAHP is the Director of Value Management at the University of Virginia Health System. Jane Torzewski RN, MAN, MBA is a Senior Category Manager for the Mayo Clinic Physician Preference Contracting team. She previously was a Senior Clinical Value Analyst on the Mayo Clinic Value Analysis team. Copyright © 2018. Published by Elsevier Inc.

  17. Is a comparative clinical trial for breast cancer tumor markers to monitor disease recurrence warranted? A value of information analysis.

    Science.gov (United States)

    Thariani, Rahber; Henry, Norah Lynn; Ramsey, Scott D; Blough, David K; Barlow, Bill; Gralow, Julie R; Veenstra, David L

    2013-05-01

    Breast cancer tumor markers are used by some clinicians to screen for disease recurrence risk. Since there is limited evidence of benefit, additional research may be warranted. To assess the potential value of a randomized clinical trial of breast tumor marker testing in routine follow-up of high-risk, stage II-III breast cancer survivors. We developed a decision-analytic model of tumor marker testing plus standard surveillance every 3-6 months for 5 years. The expected value of sample information was calculated using probabilistic simulations and was a function of: the probability of selecting the optimal monitoring strategy with current versus future information; the impact of choosing the nonoptimal strategy; and the size of the population affected. The value of information for a randomized clinical trial involving 9000 women was US$214 million compared with a cost of US$30-60 million to conduct such a trial. The probability of making an alternate, nonoptimal decision and choosing testing versus no testing was 32% with current versus future information from the trial. The impact of a nonoptimal decision was US$2150 and size of population impacted over 10 years was 308,000. The value of improved information on overall survival was US$105 million, quality of life US$37 million and test performance US$71 million. Conducting a randomized clinical trial of breast cancer tumor markers appears to offer a good societal return on investment. Retrospective analyses to assess test performance and evaluation of patient quality of life using tumor markers may also offer valuable areas of research. However, alternative investments may offer even better returns in investments and, as such, the trial concept deserves further study as part of an overall research-portfolio evaluation.

  18. Gene conversion in yeast as a function of linear energy transfer (LET) for low-LET radiation

    International Nuclear Information System (INIS)

    Unrau, P.; Morrison, D.P.; Johnson, J.R.

    1992-05-01

    The relative biological effectiveness (RBE) for low-LET radiation is known to depend on such factors as LET and dose rate. Microdosimetric calculations indicate that the biological target size could also be an important parameter, and calculations predict that the RBE for effects produced by hits in target sizes below about 100 nm should be unity for all low LET radiation. We have measured that RBE for gene conversion in yeast (a small target) for five different low LET photon sources, and the results were consistent with an RBE of unity, which agrees with microdosimetric predictions. 4 refs

  19. Feasibility of using 'lung density' values estimated from EIT images for clinical diagnosis of lung abnormalities in mechanically ventilated ICU patients.

    Science.gov (United States)

    Nebuya, Satoru; Koike, Tomotaka; Imai, Hiroshi; Iwashita, Yoshiaki; Brown, Brian H; Soma, Kazui

    2015-06-01

    This paper reports on the results of a study which compares lung density values obtained from electrical impedance tomography (EIT), clinical diagnosis and CT values (HU) within a region of interest in the lung. The purpose was to assess the clinical use of lung density estimation using EIT data. In 11 patients supported by a mechanical ventilator, the consistency of regional lung density measurements as estimated by EIT was validated to assess the feasibility of its use in intensive care medicine. There were significant differences in regional lung densities recorded in the supine position between normal lungs and diseased lungs associated with pneumonia, atelectasis and pleural effusion (normal; 240 ± 71.7 kg m(-3), pneumonia; 306 ± 38.6 kg m(-3), atelectasis; 497 ± 130 kg m(-3), pleural effusion; 467 ± 113 kg m(-3): Steel-Dwass test, p EIT images. The results of CT and EIT images from five patients in an intensive care unit showed a correlation coefficient of 0.66 ± 0.13 between the CT values (HU) and the lung density values (kg m(-3)) obtained from EIT. These results indicate that it may be possible to obtain a quantitative value for regional lung density using EIT.

  20. Congruent leadership: values in action.

    Science.gov (United States)

    Stanley, David

    2008-07-01

    To discuss the significance of an appropriate leadership theory in order to develop an understanding of clinical leadership. Leadership theories developed from management and related paradigms, particularly transformational leadership, may be ineffective in supporting nurses to gain insights into clinical leadership or to develop and implement clinical leadership skills. Instead, congruent leadership theory, based on a match between the clinical leaders' actions and their values and beliefs about care and nursing, may offer a more firm theoretical foundation on which clinical nurses can build an understanding of and capacity to implement clinical leadership or become clinical leaders. Evaluation The information used is drawn from the contemporary literature and a study conducted by the author. Leadership can be better understood when an appropriate theoretical foundation is employed. With regard to clinical leadership, congruent leadership is proposed as the most appropriate theory. It is important to recognize that leadership theories based on a management paradigm may not be appropriate for all clinical applications. Education should be aimed specifically at clinical leaders, recognizing that clinical leaders are followed not for their vision or creativity (even if they demonstrate these), but because they translate their values and beliefs about care into action.

  1. Clinical value of serum bilirubin subfractionation by high-performance liquid chromatography and conventional methods in patients with primary biliary cirrhosis

    NARCIS (Netherlands)

    Jansen, P. L.; Peters, W. H.; Janssens, A. R.

    1986-01-01

    The clinical value of serum bilirubin subfractionation, using high-performance liquid chromatography (HPLC), was studied in 26 patients with primary biliary cirrhosis (PBC) from whom 59 serum samples were obtained. Total bilirubin (TB) levels were determined by alkaline methanolysis and HPLC

  2. The clinical value of membranes in bone augmentation procedures in oral implantology: 
A systematic review of randomised controlled trials

    NARCIS (Netherlands)

    Jonker, Brend P.; Roeloffs, Maarten W. K.; Wolvius, Eppo B.; Pijpe, Justin

    2016-01-01

    To determine the clinical value of membranes in bone augmentation procedures such as ridge augmentation with simultaneous (one-stage) and delayed (two-stage) implant placement, sinus augmentation surgery, ridge preservation and immediate implant placement. In April 2016, Embase, Medline (Ovid-SP),

  3. [A Retrospective Study of Mean Computed Tomography Value to Predict 
the Tumor Invasiveness in AAH and Clinical Stage Ia Lung Cancer].

    Science.gov (United States)

    Wu, Hanran; Liu, Changqing; Xu, Meiqing; Xiong, Ran; Xu, Guangwen; Li, Caiwei; Xie, Mingran

    2018-03-20

    Recently, the detectable rate of ground-glass opacity (GGO ) was significantly increased, a appropriate diagnosis before clinic treatment tends to be important for patients with GGO lesions. The aim of this study is to validate the ability of the mean computed tomography (m-CT) value to predict tumor invasiveness, and compared with other measurements such as Max CT value, GGO size, solid size of GGO and C/T ratio (consolid/tumor ratio, C/T) to find out the best measurement to predict tumor invasiveness. A retrospective study was conducted of 129 patients who recieved lobectomy and were pathological confirmed as atypical adenomatous pyperplasia (AAH) or clinical stage Ia lung cance in our center between January 2012 and December 2013. Of those 129 patients, the number of patients of AAH, AIS, AIS and invasive adenocarcinoma were 43, 26, 17 and 43, respectively. We defined AAH and AIS as noninvasive cancer (NC), MIA and invasive adenocarcinoma were categorized as invasive cancer(IC). We used receiver operating characteristic (ROC) curve analysis to compare the ability to predict tumor invasiveness between m-CT value, consolidation/tumor ratio, tumor size and solid size of tumor. Multiple logistic regression analyses were performed to determine the independent variables for prediction of pathologic more invasive lung cancer. 129 patients were enrolled in our study (59 male and 70 female), the patients were a median age of (62.0±8.6) years (range, 44 to 82 years). The two groups were similar in terms of age, sex, differentiation (P>0.05). ROC curve analysis was performed to determine the appropriate cutoff value and area under the cure (AUC). The cutoff value of solid tumor size, tumor size, C/T ratio, m-CT value and Max CT value were 9.4 mm, 15.3 mm, 47.5%, -469.0 HU and -35.0 HU, respectively. The AUC of those variate were 0.89, 0.79, 0.82, 0.90, 0.85, respectively. When compared the clinical and radiologic data between two groups, we found the IC group was strongly

  4. Clinical Value of Thyrotropin Receptor Antibodies for the Differential Diagnosis of Interferon Induced Thyroiditis.

    Science.gov (United States)

    Benaiges, D; Garcia-Retortillo, M; Mas, A; Cañete, N; Broquetas, T; Puigvehi, M; Chillarón, J J; Flores-Le Roux, J A; Sagarra, E; Cabrero, B; Zaffalon, D; Solà, R; Pedro-Botet, J; Carrión, J A

    2016-01-01

    The clinical value of thyrotropin receptor antibodies for the differential diagnosis of thyrotoxicosis induced by pegylated interferon-alpha remains unknown. We analyzed the diagnostic accuracy of thyrotropin receptor antibodies in the differential diagnosis of thyrotoxicosis in patients with chronic hepatitis C (CHC) receiving pegylated interferon-alpha plus ribavirin. Retrospective analysis of 274 patients with CHC receiving pegylated interferon-alpha plus ribavirin. Interferon-induced thyrotoxicosis was classified according to clinical guidelines as Graves disease, autoimmune and non- autoimmune destructive thyroiditis. 48 (17.5%) patients developed hypothyroidism, 17 (6.2%) thyrotoxicosis (6 non- autoimmune destructive thyroiditis, 8 autoimmune destructive thyroiditis and 3 Graves disease) and 22 "de novo" thyrotropin receptor antibodies (all Graves disease, 2 of the 8 autoimmune destructive thyroiditis and 17 with normal thyroid function). The sensitivity and specificity of thyrotropin receptor antibodies for Graves disease diagnosis in patients with thyrotoxicosis were 100 and 85%, respectively. Patients with destructive thyroiditis developed hypothyroidism in 87.5% of autoimmune cases and in none of those with a non- autoimmune etiology (pthyroid scintigraphy for the differential diagnosis of thyrotoxicosis in CHC patients treated with pegylated interferon. © Georg Thieme Verlag KG Stuttgart · New York.

  5. The feasibility, perceived satisfaction, and value of using synchronous webinars to educate clinical research professionals on reporting adverse events in clinical trials: a report from the Children's Oncology Group.

    Science.gov (United States)

    Borgerson, Dawn; Dino, Jennifer

    2012-01-01

    Clinical research professionals are faced with decreased funding and increased workloads; innovative methods of professional development programs are necessary to accommodate these factors. This study evaluated the feasibility, perceived satisfaction, and value of using webinars to educate clinical research professionals on reporting adverse events commonly experienced in pediatric oncology clinical trials. The setting incorporated synchronous web-based educational technology. Constructivist learning provides the theoretical framework for this study. Participants evaluated the professional development program at 2 time points: (a) at the conclusion and (b) 4 to 6 weeks afterward, using survey method. Synchronous webinars were both economical and effective in educating clinical research professionals across institutional sites. Participants reported exceptionally high levels of satisfaction with the accessibility, scope, quality, and interactivity of the professional development program. The vast majority of participants reported that the education would assist with reporting adverse events in pediatric oncology clinical trials and this perception persisted into clinical practice. Although the results of this study were intended to guide future educational efforts of the Children's Oncology Group, they may also apply to other cooperative groups.

  6. [Value of history and clinical and laboratory data for the diagnosis of dehydration due to acute diarrhea in children younger than 5 years].

    Science.gov (United States)

    Pruvost, Isabelle; Dubos, François; Aurel, Marie; Hue, Valérie; Martinot, Alain

    2008-04-01

    Acute diarrhea is frequent, costly because of the number of hospital admissions required, and sometimes serious, even fatal to children in France. The clinical diagnosis of dehydration is difficult, but essential to determine management. To summarize the published data on the value of clinical history, clinical signs and laboratory results for diagnosing dehydration during acute diarrhea in young (1 month-5 years) non-malnourished children. Four databases (Medline, INIST, Ovid, and Cochrane) were searched through November 2006, with the key words "dehydration" subcategories "diagnosis, or etiology, or history", "diarrhea" subcategory "diagnosis", and age limits "infant or preschool child". We selected the articles and reviews that included as an endpoint for dehydration "weight gain > 5% after recovery" (the gold standard). Thirteen studies were selected. No single clinical history item, clinical sign or laboratory value was sufficient to discriminate between children with and without dehydration. The reproducibility of clinical signs varied substantially between studies. Persistent skin folds and signs of vasoconstriction contributed the most information, with good specificity but sensitivity dehydration. No dehydration scale has been validated. None of the studies selected had a very high level of proof (level 1 and 2); neither signs nor scores have been validated internally or externally because of the low number of subjects. The diagnosis of dehydration due to acute diarrhea in young children depends on the number of signs present, since no individual element of clinical history, clinical picture or laboratory tests distinguished dehydration. Other studies are necessary.

  7. Clinical value of acoustic radiation force impulse in quantitative prediction of the degree of esophageal varices in patients with liver cirrhosis

    Directory of Open Access Journals (Sweden)

    CHEN Min

    2018-01-01

    Full Text Available Objective To investigate the clinical value of acoustic radiation force impulse (ARFI in quantitative prediction of the degree of esophageal varices in patients with cirrhotic portal hypertension. Methods A total of 116 patients with liver cirrhosis who were admitted to 302 Hospital of PLA from October 2014 to February 2016 were enrolled. ARFI was used to measure real-time liver and spleen stiffness for all patients. With the degree of esophageal varices determined by gastroscopy as the gold standard for diagnosis, these patients were divided into non-varices group (EV0, 16 patients, mild varices group (EV1, 39 patients, moderate varices group (EV2, 26 patients, and severe varices group (EV3, 35 patients. The receiver operating characteristic (ROC curve was used to analyze the clinical value of liver/spleen ARFI in predicting the degree of esophageal varices. An analysis of variance or the Kruskal-Wallis H test was used for comparison of continuous data between multiple groups, and the least significant difference Mann-Whitney U test was used for further comparison between any two groups; the chi-square test was used for comparison of categorical data between groups. The Spearman correlation analysis was used to investigate the correlation between the stiffness measured by ARFI and the degree of esophageal varices. Results The ARFI value of the spleen was 2.54±0.34 m/s for EV0 patients, 3.05±0.34 m/s for EV1 patients, 3.48±0.50 m/s for EV2 patients, and 3.69±0.33 m/s for EV3 patients (χ2=60.121,P<0.001. The ARFI value of the spleen was positively correlated with the grade of esophageal varices (r=0.713, P<0.001. The areas under the ROC curve for the ARFI value of the spleen in the diagnosis of ≥EV1, ≥EV2, or EV3 esophageal varices were 0.93, 0.88, and 0.83, respectively. There was no significant difference in the ARFI value of the liver between groups (P=0.085, and the ARFI value of the liver was not correlated with the degree of

  8. Reference line-pair values of panoramic radiographs using an arch-form phantom stand to assess clinical image quality

    International Nuclear Information System (INIS)

    Choi, Da Hye; Choi, Bo Ram; Huh, Kyung Hoe; Heo, Min Suk; Choi, Soon Chul; Choi, Jin Woo; Yi, Won Jin; Lee, Sam Sun

    2013-01-01

    This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.

  9. Reference line-pair values of panoramic radiographs using an arch-form phantom stand to assess clinical image quality

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Da Hye; Choi, Bo Ram; Huh, Kyung Hoe; Heo, Min Suk; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Choi, Jin Woo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Cheonan (Korea, Republic of); Yi, Won Jin; Lee, Sam Sun [Dept. of Oral and Maxillofacial Radiology, BK21 Craniomaxillofacial Life Science, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2013-03-15

    This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.

  10. Clinical value of 18F-FDG coincidence imaging for diagnosis of nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Ning Yanli; Lou Cen; Huang Zhongke; Shi Guohua; Chen Dongfang; Mu Da

    2012-01-01

    Objective: To investigate the value of 18 F-FDG coincidence imaging for diagnosis of nasopharyngeal carcinoma. Methods: A total of 45 patients with nasopharyngeal carcinoma (33 males and 12 females, average age (55.56 ± 13.50) years), who underwent 18 F-FDG coincidence imaging before treatment, were studied retrospectively. The images of 18 F-FDG coincidence imaging (GE Millennium VG SPECT) and MRI were analyzed. The radioactivity ratio of the accumulated regions to cerebellum (T/NT)was calculated by ROI technique. The volume of nasopharyngeal carcinoma was recorded by MRI. The positive rates of 18 F-FDG coincidence imaging and EB virus-related antibody measurements were compared by paired χ 2 test. The correlation between T/NT ratios and tumor volumes were tested by Pearson correlation, and then ROC curves were established. The T/NT ratios and tumor volumes of different groups (different first symptoms, clinical stages, T stages, pathological classification and outcomes, with or without lymph node enlargement) were compared by t-test and rank sum test. Results: The positive rate of 18 F-FDG coincidence imaging was 97.78% (44/45), and the positive rate of EB virus-related antibody measurement was 95.56% (43/45, χ 2 =1.33, P>0.05). The T/NT ratio (2.439 ±1.119) and tumor volume ((7.311 ± 8.280) cm 3 ) of primary lesions had a positive correlation (r=0.463, P<0.05). The cut-off values of T/NT ratio and the tumor volume were 2.396 and 7.348 cm 3 , respectively, by ROC curves. T/NT ratios in groups with or without first symptom of epistaxis (2.847 ± 1.254 vs 2.082 ± 0.863, t=-2.409) and groups with or without facial numbness (2.855 ± 1.261 vs 2.134 ± 0.913, t=-2.225) were both significantly different (both P<0.05). T/NT ratios of differentiated and undifferentiated cancer were 2.266 ± 0.997 and 2.971 ± 1.351, respectively (t=-2.018, P<0.05). There was a significant difference of tumor volumes between groups with or without facial numbness (t=-2.684, P<0

  11. Clinical Value of High Mobility Group Box 1 and the Receptor for Advanced Glycation End-products in Head and Neck Cancer: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Nguyen, Austin

    2016-04-01

    Full Text Available Introduction High mobility group box 1 is a versatile protein involved in gene transcription, extracellular signaling, and response to inflammation. Extracellularly, high mobility group box 1 binds to several receptors, notably the receptor for advanced glycation end-products. Expression of high mobility group box 1 and the receptor for advanced glycation end-products has been described in many cancers. Objectives To systematically review the available literature using PubMed and Web of Science to evaluate the clinical value of high mobility group box 1 and the receptor for advanced glycation end-products in head and neck squamous cell carcinomas. Data synthesis A total of eleven studies were included in this review. High mobility group box 1 overexpression is associated with poor prognosis and many clinical and pathological characteristics of head and neck squamous cell carcinomas patients. Additionally, the receptor for advanced glycation end-products demonstrates potential value as a clinical indicator of tumor angiogenesis and advanced staging. In diagnosis, high mobility group box 1 demonstrates low sensitivity. Conclusion High mobility group box 1 and the receptor for advanced glycation end-products are associated with clinical and pathological characteristics of head and neck squamous cell carcinomas. Further investigation of the prognostic and diagnostic value of these molecules is warranted.

  12. Added clinical value of the inferior temporal EEG electrode chain.

    Science.gov (United States)

    Bach Justesen, Anders; Eskelund Johansen, Ann Berit; Martinussen, Noomi Ida; Wasserman, Danielle; Terney, Daniella; Meritam, Pirgit; Gardella, Elena; Beniczky, Sándor

    2018-01-01

    To investigate the diagnostic added value of supplementing the 10-20 EEG array with six electrodes in the inferior temporal chain. EEGs were recorded with 25 electrodes: 19 positions of the 10-20 system, and six additional electrodes in the inferior temporal chain (F9/10, T9/10, P9/10). Five-hundred consecutive standard and sleep EEG recordings were reviewed using the 10-20 array and the extended array. We identified the recordings with EEG abnormalities that had peak negativities at the inferior temporal electrodes, and those that only were visible at the inferior temporal electrodes. From the 286 abnormal recordings, the peak negativity was at the inferior temporal electrodes in 81 cases (28.3%) and only visible at the inferior temporal electrodes in eight cases (2.8%). In the sub-group of patients with temporal abnormalities (n = 134), these represented 59% (peak in the inferior chain) and 6% (only seen at the inferior chain). Adding six electrodes in the inferior temporal electrode chain to the 10-20 array improves the localization and identification of EEG abnormalities, especially those located in the temporal region. Our results suggest that inferior temporal electrodes should be added to the EEG array, to increase the diagnostic yield of the recordings. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  13. The Value of the SYNTAX Score II in Predicting Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Implantation.

    Science.gov (United States)

    Ryan, Nicola; Nombela-Franco, Luis; Jiménez-Quevedo, Pilar; Biagioni, Corina; Salinas, Pablo; Aldazábal, Andrés; Cerrato, Enrico; Gonzalo, Nieves; Del Trigo, María; Núñez-Gil, Iván; Fernández-Ortiz, Antonio; Macaya, Carlos; Escaned, Javier

    2017-11-27

    The predictive value of the SYNTAX score (SS) for clinical outcomes after transcatheter aortic valve implantation (TAVI) is very limited and could potentially be improved by the combination of anatomic and clinical variables, the SS-II. We aimed to evaluate the value of the SS-II in predicting outcomes in patients undergoing TAVI. A total of 402 patients with severe symptomatic aortic stenosis undergoing transfemoral TAVI were included. Preprocedural TAVI angiograms were reviewed and the SS-I and SS-II were calculated using the SS algorithms. Patients were stratified in 3 groups according to SS-II tertiles. The coprimary endpoints were all-cause death and major adverse cardiovascular events (MACE), a composite of all-cause death, cerebrovascular event, or myocardial infarction at 1 year. Increased SS-II was associated with higher 30-day mortality (P=.036) and major bleeding (P=.015). The 1-year risk of death and MACE was higher among patients in the 3rd SS-II tertile (HR, 2.60; P=.002 and HR, 2.66; P<.001) and was similar among patients in the 2nd tertile (HR, 1.27; P=.507 and HR, 1.05; P=.895) compared with patients in the 1st tertile. The highest SS-II tertile was an independent predictor of long-term mortality (P=.046) and MACE (P=.001). The SS-II seems more suited to predict clinical outcomes in patients undergoing TAVI than the SS-I. Increased SS-II was associated with poorer clinical outcomes at 1 and 4 years post-TAVI, independently of the presence of coronary artery disease. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  14. submitter Next generation multi-scale biophysical characterization of high precision cancer particle radiotherapy using clinical proton, helium-, carbon- and oxygen ion beams

    CERN Document Server

    Dokic, Ivana; Niklas, Martin; Zimmermann, Ferdinand; Chaudhri, Naved; Krunic, Damir; Tessonnier, Thomas; Ferrari, Alfredo; Parodi, Katia; Jäkel, Oliver; Debus, Jürgen; Haberer, Thomas; Abdollahi, Amir

    2016-01-01

    The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival. The cell fluorescence ion track hybrid detector (Cell-Fit-HD) technology was employed to detect particle traverse per cell nucleus. Across a panel of radiobiological surrogates studied such as late ROS accumulation and apoptosis (caspase 3/7 activation), the relative biological effectiveness (RBE) chiefly correlated with the radiation species-specific spatio-temporal pattern of DNA double strand break ...

  15. Increasing fetal ovine number per gestation alters fetal plasma clinical chemistry values.

    Science.gov (United States)

    Zywicki, Micaela; Blohowiak, Sharon E; Magness, Ronald R; Segar, Jeffrey L; Kling, Pamela J

    2016-08-01

    Intrauterine growth restriction (IUGR) is interconnected with developmental programming of lifelong pathophysiology. IUGR is seen in human multifetal pregnancies, with stepwise rises in fetal numbers interfering with placental nutrient delivery. It remains unknown whether fetal blood analyses would reflect fetal nutrition, liver, and excretory function in the last trimester of human or ovine IUGR In an ovine model, we hypothesized that fetal plasma biochemical values would reflect progressive placental, fetal liver, and fetal kidney dysfunction as the number of fetuses per gestation rose. To determine fetal plasma biochemical values in singleton, twin, triplet, and quadruplet/quintuplet ovine gestation, we investigated morphometric measures and comprehensive metabolic panels with nutritional measures, liver enzymes, and placental and fetal kidney excretory measures at gestational day (GD) 130 (90% gestation). As anticipated, placental dysfunction was supported by a stepwise fall in fetal weight, fetal plasma glucose, and triglyceride levels as fetal number per ewe rose. Fetal glucose and triglycerides were directly related to fetal weight. Plasma creatinine, reflecting fetal renal excretory function, and plasma cholesterol, reflecting placental excretory function, were inversely correlated with fetal weight. Progressive biochemical disturbances and growth restriction accompanied the rise in fetal number. Understanding the compensatory and adaptive responses of growth-restricted fetuses at the biochemical level may help explain how metabolic pathways in growth restriction can be predetermined at birth. This physiological understanding is important for clinical care and generating interventional strategies to prevent altered developmental programming in multifetal gestation. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  16. Some long-term effects of negative pions in mice exposed to partial body irradiation

    International Nuclear Information System (INIS)

    Coggle, J.E.

    1977-01-01

    The long-term effects of partial body exposure of one-day-old mice given either 60 Co γ rays or negative pions have been studied. Both radiations produced considerable life-shortening; for pions 6.8 +- 1.5% of life was lost per 100 rad and for γ rays the value was 5.7 +- 0.5% per 100 rad. The RBE of pions for ten weeks of life-shortening was about 1.3 compared with 60 Co γ rays, although at lower doses the RBE may be higher reaching about two for six weeks of life-shortening. The incidence rate of tumours at any particular age was greater in mice irradiated with pions at the peak and in those given higher doses of γ rays than in the controls. (author)

  17. SU-E-T-494: Influence of Proton Track-Cell Nucleus Incidence Angle On Relative Biological Effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Pater, P; Backstrom, G; Enger, S; Seuntjens, J; El Naqa, I [McGill University, Montreal, Quebec (Canada); Villegas, F; Ahnesjo, A [Uppsala University, Uppsala (Sweden)

    2015-06-15

    Purpose: To explain a Monte Carlo (MC) simulation artifact whereby differences in relative biological effectiveness (RBE) in the induction of initial double strand breaks are observed as a function of the proton track incidence angles in a geometric cell nucleus model. Secondly, to offer an alternative isotropic irradiation procedure to mitigate this effect. Methods: MC tracks of 1 MeV protons were generated in an event-by-event mode. They were overlaid on a cylindrical model of a cell nucleus containing 6×109 nucleotide base pairs. The tracks incidence angle θ with respect to the cell nucleus’s axis was varied in 10 degrees intervals, each time generating one hundred fractions of ∼2 Gy. Strand breaks were scored in the modeled DNA sugar-phosphate groups and further sub-classified into single or double strand breaks (ssbs or dsbs). For each angle, an RBE for the induction of initial dsbs with reference to Co-60 was calculated. Results: Our results show significant angular dependencies of RBE, with maximum values for incidence angles parallel to the nucleus central axis. Further examination shows that the higher cross-sections for the creation of dsbs is due to the preferential alignment of tracks with geometrical sub-parts of the cell nucleus model, especially the nucleosomes containing the sugar-phosphate groups. To alleviate the impact of this simulation artifact, an average RBE was calculated with a procedure based on a weighted sampling of the angular data. Conclusion: This work demonstrates a possible numerical artifact in estimated RBE if the influence of the particle incidence angle is not correctly taken into account. A correction procedure is presented to better conform the simulations to real-life experimental conditions. We would like to acknowledge support from the Fonds de recherche du Quebec Sante (FRQS), from the CREATE Medical Physics Research Training Network grant (number 432290) of NSERC, support from NSERC under grants RGPIN 397711-11 and

  18. Classified study and clinical value of the phase imaging features

    International Nuclear Information System (INIS)

    Dang Yaping; Ma Aiqun; Zheng Xiaopu; Yang Aimin; Xiao Jiang; Gao Xinyao

    2000-01-01

    445 patients with various heart diseases were examined by the gated cardiac blood pool imaging, and the phase was classified. The relationship between the seven types with left ventricular function index, clinical heart function, different heart diseases as well as electrocardiograph was studied. The results showed that the phase image classification could match with the clinical heart function. It can visually, directly and accurately indicate clinical heart function and can be used to identify diagnosis of heart disease

  19. Value-based genomics.

    Science.gov (United States)

    Gong, Jun; Pan, Kathy; Fakih, Marwan; Pal, Sumanta; Salgia, Ravi

    2018-03-20

    Advancements in next-generation sequencing have greatly enhanced the development of biomarker-driven cancer therapies. The affordability and availability of next-generation sequencers have allowed for the commercialization of next-generation sequencing platforms that have found widespread use for clinical-decision making and research purposes. Despite the greater availability of tumor molecular profiling by next-generation sequencing at our doorsteps, the achievement of value-based care, or improving patient outcomes while reducing overall costs or risks, in the era of precision oncology remains a looming challenge. In this review, we highlight available data through a pre-established and conceptualized framework for evaluating value-based medicine to assess the cost (efficiency), clinical benefit (effectiveness), and toxicity (safety) of genomic profiling in cancer care. We also provide perspectives on future directions of next-generation sequencing from targeted panels to whole-exome or whole-genome sequencing and describe potential strategies needed to attain value-based genomics.

  20. Unipolar Endocardial Voltage Mapping in the Right Ventricle: Optimal Cutoff Values Correcting for Computed Tomography-Derived Epicardial Fat Thickness and Their Clinical Value for Substrate Delineation.

    Science.gov (United States)

    Venlet, Jeroen; Piers, Sebastiaan R D; Kapel, Gijsbert F L; de Riva, Marta; Pauli, Philippe F G; van der Geest, Rob J; Zeppenfeld, Katja

    2017-08-01

    Low endocardial unipolar voltage (UV) at sites with normal bipolar voltage (BV) may indicate epicardial scar. Currently applied UV cutoff values are based on studies that lacked epicardial fat information. This study aimed to define endocardial UV cutoff values using computed tomography-derived fat information and to analyze their clinical value for right ventricular substrate delineation. Thirty-three patients (50±14 years; 79% men) underwent combined endocardial-epicardial right ventricular electroanatomical mapping and ablation of right ventricular scar-related ventricular tachycardia with computed tomographic image integration, including computed tomography-derived fat thickness. Of 6889 endocardial-epicardial mapping point pairs, 547 (8%) pairs with distance 1.50 mV, the optimal endocardial UV cutoff for identification of epicardial BV the curve, 0.75; sensitivity, 60%; specificity, 79%) and cutoff for identification of abnormal epicardial electrogram was 3.7 mV (area under the curve, 0.88; sensitivity, 100%; specificity, 67%). The majority of abnormal electrograms (130 of 151) were associated with transmural scar. Eighty-six percent of abnormal epicardial electrograms had corresponding endocardial sites with BV the remaining could be identified by corresponding low endocardial UV right ventricular scar, an endocardial UV cutoff value of 3.9 mV is more accurate than previously reported cutoff values. Although the majority of epicardial abnormal electrograms are associated with transmural scar with low endocardial BV, the additional use of endocardial UV at normal BV sites improves the diagnostic accuracy resulting in identification of all epicardial abnormal electrograms at sites with <1.0 mm fat. © 2017 American Heart Association, Inc.

  1. Value as the key concept in the health care system: how it has influenced medical practice and clinical decision-making processes

    Directory of Open Access Journals (Sweden)

    Marzorati C

    2017-03-01

    Full Text Available Chiara Marzorati,1,2 Gabriella Pravettoni2,3 1Foundations of the Life Sciences, Bioethics and Cognitive Science, European School of Molecular Medicine (SEMM, 2Applied Research Division for Cognitive and Psychological Science, European Institute of Oncology, 3Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy Abstract: In the last 10 years, value has played a key role in the health care system. In this concept, innovations in medical practice and the increasing importance of patient centeredness have contributed to draw the attention of the medical community. Nonetheless, a large consensus on the meaning of “value” is still lacking: patients, physicians, policy makers, and other health care professionals have different ideas on which component of value may play a prominent role. Yet, shared clinical decision-making and patient empowerment have been recognized as fundamental features of the concept of value. Different paradigms of health care system embrace different meanings of value, and the absence of common and widely accepted definition does not help to identify a unique model of care in health care system. Our aim is to provide an overview of those paradigms that have considered value as a key theoretical concept and to investigate how the presence of value can influence the medical practice. This article may contribute to draw attention toward patients and propose a possible link between health care system based on “value” and new paradigms such as patient-centered system (PCS, patient empowerment, and P5 medicine, in order to create a predictive, personalized, preventive, participatory, and psycho-cognitive model to treat patients. Indeed, patient empowerment, value-based system, and P5 medicine seem to shed light on different aspects of a PCS, and this allows a better understanding of people under care. Keywords: health care system, value, value-based medicine, patient empowerment, clinical decision

  2. 'What the patient wants': an investigation of the methods of ascertaining patient values in evidence-based medicine and values-based practice.

    Science.gov (United States)

    Wieten, Sarah

    2018-02-01

    Evidence-Based Medicine (EBM), Values-Based Practice (VBP) and Person-Centered Healthcare (PCH) are all concerned with the values in play in the clinical encounter. However, these recent movements are not in agreement about how to discover these relevant values. In some parts of EBM textbooks, the prescribed method for discovering values is through social science research on the average values in a particular population. VBP by contrast always investigates the individually held values of the different stakeholders in the particular clinical encounter, although the account has some other difficulties. I argue that although average values for populations might be very useful in informing questions of resource distribution and policy making, their use cannot replace the individual solicitation of patient (and other stakeholder) values in the clinical encounter. Because of the inconsistency of the EBM stance on values, the incompatibility of some versions of the EBM treatment of values with PCH, and EBM's attempt to transplant research methods from science into the realm of values, I must recommend the use of the VBP account of values discovery. © 2015 John Wiley & Sons, Ltd.

  3. Diagnostic value of brain chronic black holes on T1-weighted MR images in clinically isolated syndromes.

    Science.gov (United States)

    Mitjana, Raquel; Tintoré, Mar; Rocca, Maria A; Auger, Cristina; Barkhof, Frederik; Filippi, Massimo; Polman, Chris; Fazekas, Franz; Huerga, Elena; Montalban, Xavier; Rovira, Alex

    2014-10-01

    Non-enhancing black holes (neBHs) are more common in multiple sclerosis (MS) patients with longer disease durations and progressive disease subtypes. Our aim was to analyse the added value of neBHs in patients with clinically isolated syndromes (CISs) for predicting conversion to clinically definite MS (CDMS). Patients were classified based on the presence or absence of neBHs and on the number of Barkhof-Tintoré (B-T) criteria fulfilled. Dissemination in space (DIS) was defined as the presence of at least three of the four B-T criteria. Dissemination in time (DIT)1 was defined by simultaneous presence of enhancing and non-enhancing lesions. DIT2 was defined by simultaneous presence of neBHs and T2 lesions not apparent on T1-weighted images. Focal T2-hyperintense brain lesions were identified in 87.7% of the 520 CIS patients, and 41.4% of them presented at least one neBH. Patients meeting DIS, DIT1, and DIT2 had a significantly higher rate of conversion to CDMS. After adjusting for DIS, only patients who fulfilled DIT1 preserved a significant increase in CDMS conversion. Non-enhancing black holes in CIS patients are associated with a higher risk of conversion to CDMS. However, the predictive value of this finding is lost when added to the DIS criteria. © The Author(s) 2014.

  4. Radiation biophysical studies with mammalian cells and a modulated carbon ion beam

    International Nuclear Information System (INIS)

    Chapman, J.D.; Blakely, E.A.; Smith, K.C.; Urtasun, R.C.; Lyman, J.T.; Tobias, C.A.

    1978-01-01

    Chinese hamster (V-79) and human kidney (T-1) cells were irradiated in stirred suspensions placed at various positions in the plateau and extended Bragg peak of a 400-MeV/amu carbon ion beam. The range of the ions was modulated by a lead (translational) ridge filter and a brass (spiral) ridge filter designed to produce extended peaks of approximately 4 and 10 cm, respectively. Stationary-phase and G 1 -phase populations of Chinese hamster cells were found to have different absolute radiosensitivities which, in turn, were different from that of asynchronous human kidney cells. The increase in relative biological effectiveness (RBE) observed as carbon ions were slowed down and stopped in water was similar for the three cell populations at doses greater than 400 rad. At lower doses the RBE was greater for the hamster cell populations than for the human kidney cells. The gain in RBE (at the 50% survival level) between the plateaus and the middle region of the extended peaks was approximately 2.0 and 1.7 for the 4- and 10-cm extended peaks, respectively. Oxygen enhancement ratios (OER) were determined at the 10% survival levels with stationary-phase populations of hamster cells. Values of 2.8, 2.65, and 1.65 were obtained for the OER of 220-kV x rays, plateau carbon, and the middle region of the 4-cm carbon peak, respectively. Across the 10-cm carbon peak the OER was found to vary between values of 2.4 to 1.55 from the proximal to distal positions

  5. Clinical value of determination of TSH-binding inhibiting immunoglobulins (TBII) by a radioreceptor assay

    International Nuclear Information System (INIS)

    Heberling, H.J.; Bierwolf, B.; Lohmann, D.

    1986-01-01

    The clinical value of a commercial kit for determination of TBII was evaluated. 50 patients with untreated Graves' disease, 21 patients with Graves' disease before and during medical therapy, 18 patients after finishing medical therapy and 10 patients after surgical treatment were examined. Besides these, 41 patients with other thyroid diseases and 36 patients without any thyroid disorder were included. In 47 (94%) of 50 patients with untreated Graves' disease TBII were detectable in serum using a TSH standard curve. Binding activities exceeding 10 U/l TSH equivalents were regarded as positive. In other thyroid diseases TBII were negative with the exception of 3 of 22 patient with autonomously functioning thyroid nodules. After 12 months of antithyroid drug treatment of 19 patients the incidence of positive antibody findings was 26%. During follow-up after medical therapy (1-9 years) 7 of 18 patients had increased TBII in correlation with clinical and functional findings. The determination of TBII by TRAK assay proved to be a sensitive and specific method. The assay can be used to differentiate between hyperthyroidism of autoimmune or non-immunogenic origin. Thus the method seems to be helpful for the follow-up under medical treatment of patients with Graves' disease. (author)

  6. Review of clinically accessible methods to determine lean body mass for normalization of standardized uptake values

    International Nuclear Information System (INIS)

    DEVRIESE, Joke; POTTEL, Hans; BEELS, Laurence; MAES, Alex; VAN DE WIELE, Christophe; GHEYSENS, Olivier

    2016-01-01

    With the routine use of 2-deoxy-2-[ 18 F]-fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scans, metabolic activity of tumors can be quantitatively assessed through calculation of SUVs. One possible normalization parameter for the standardized uptake value (SUV) is lean body mass (LBM), which is generally calculated through predictive equations based on height and body weight. (Semi-)direct measurements of LBM could provide more accurate results in cancer populations than predictive equations based on healthy populations. In this context, four methods to determine LBM are reviewed: bioelectrical impedance analysis, dual-energy X-ray absorptiometry. CT, and magnetic resonance imaging. These methods were selected based on clinical accessibility and are compared in terms of methodology, precision and accuracy. By assessing each method’s specific advantages and limitations, a well-considered choice of method can hopefully lead to more accurate SUVLBM values, hence more accurate quantitative assessment of 18F-FDG PET images.

  7. The study on clinical value of the detection about serum and Unconjugated Bilirubin in diagnosis of neonatal jaundice.

    Science.gov (United States)

    Wang, Guangzhou; Wang, Jiefei; Huang, Nannan; Yu, Fengqin

    2016-01-01

    In this paper, the clinical value of the detection about serum and unconjugated bilirubin (UCB) in neonatal jaundice was studied to found an effective and rapid method for diagnose of neonatal jaundice. ALB (Serum Albumin), total serum bilirubin (TSB) and UCB were detected by ELISA method among the 100 cases with neonatal jaundice selected for the study. The values of ALB, UCB and TSB in moderate jaundice patients were (42.83±3.87) g/L, (287.35±44.38) μm/L, (304.16±43.40) μm/L, respectively; as for the severe jaundice patients, the values were (38.41±4.82) g/L, (354.38±48.75) μm/L, (375.20±47.51) μm/L. The results showed significant differences with the pjaundice patients. The level of ALB, UCB, TSB in hemolytic jaundice, obstructive jaundice and jaundice caused by other infections also had significant differences, and the difference was statistically significant (pjaundice.

  8. The value of a core clinical rotation in urology for medical students.

    Science.gov (United States)

    Patel, Premal; Nayak, Jasmir G; McGregor, Thomas B

    2015-01-01

    In 2013, our institution underwent a change to the undergraduate medical curriculum whereby a clinical urology rotation became mandatory. In this paper, we evaluated the perceived utility and value of this change in the core curriculum. Third year medical students, required to complete a mandatory 1-week clinical urology rotation, were asked to complete a survey before and after their rotation. Fourth year medical students, not required to complete this rotation, were also asked to complete a questionnaire. Chi-squared and Fisher's exact test were used for data analysis. In total, 108 third year students rotated through urology during the study period. Of these, 66 (61%) completed the pre-rotation survey and 54 (50%) completed the post-rotation survey. In total, there were 110 fourth year students. Of these, 44 (40%) completed the questionnaire. After completing their mandatory rotations, students felt more comfortable managing and investigating common urological problems, such as hematuria and renal colic. Students felt they had a better understanding of how to insert a Foley catheter and felt comfortable independently inserting a Foley catheter. Importantly, students felt they knew when to consult urology and were also more likely to consider a career in urology. Compared to fourth year students, third year students felt urology was an important component to a family medicine practice and felt they had a better understanding of when to consult urology. The introduction of a mandatory urology rotation for undergraduate medical students leads to a perceived improvement in fundamental urological knowledge and skill set of rotating students. This mandatory rotation provides a valuable experience that validates its inclusion.

  9. A review of the empirical evidence of the value of structuring and coding of clinical information within electronic health records for direct patient care

    Directory of Open Access Journals (Sweden)

    Dipak Kalra

    2013-05-01

    Full Text Available Background The case has historically been presented that structured and/or coded electronic health records (EHRs benefit direct patient care, but the evidence base for this is not well documented.Methods We searched for evidence of direct patient care value from the use of structured and/or coded information within EHRs. We interrogated nine international databases from 1990 to 2011. Value was defined using the Institute of Medicine’s six areas for improvement for healthcare systems: effectiveness, safety, patient-centredness, timeliness, efficiency and equitability. We included studies satisfying the Cochrane Effective Practice and Organisation of Care (EPOC group criteria.Results Of 5016 potentially eligible papers, 13 studies satisfied our criteria: 10 focused on effectiveness, with eight demonstrating potential for improved proxy and actual clinical outcomes if a structured and/or coded EHR was combined with alerting or advisory systems in a focused clinical domain. Three studies demonstrated improvement in safety outcomes. No studies were found reporting value in relation to patient-centredness, timeliness, efficiency or equitability.Conclusions We conclude that, to date, there has been patchy effort to investigate empirically the value from structuring and coding EHRs for direct patient care. Future investments in structuring and coding of EHRs should be informed by robust evidence as to the clinical scenarios in which patient care benefits may be realised.

  10. Clinical value of serum TRAb levels determination in diagnosis of Graves's disease

    International Nuclear Information System (INIS)

    Huang Zhaosui; Huang Chunhong; Liu Kaiyuan; Huang Shengli

    2005-01-01

    Objective: To investigate the clinical diagnostic value of serum TRAb levels determination in patients with Graves' disease. Methods: Serum TRAb (with RRA), FT 3 , FT 4 , TSH (with CLIA) levels were measured in 223 patients with Graves' disease both before and 6, 12, 36 months after treatment with antithyroid drugs (ATD) as well as in 50 controls. Results: Positive rate of serum TRAb was 93.3% in patients with Graves' disease before treatment. Six months after ATD therapy the positive rate dropped to 41.3%, being still significantly higher than that in controls (P<0.05). The TRAb positive rate dropped steadily with 12 (18.3% ), 24 (8.9% ) and 36 months (4.9%) of ATD treatment. In the 21 patients who had hyperthyroidism recurred after the course of treatment, TRAb remained positive in 18 of them (80.7%). Conclusion: Persistent positive TRAb despite euthyroid status in patients with Graves' disease after seemingly successful ATD treatment donates persistent immunodysfunction and possible recurrence. It is mandatory to continue ATD treatment until TRAb negative. (authors)

  11. The clinical value of detecting INS and C - P in essential hypertension

    International Nuclear Information System (INIS)

    Huang Jianmin; Sun Shuqiang; Liu Xiaomei

    2001-01-01

    In order to explore the clinical value of insulin (INS) and C - peptide (C-P) in essential hypertension patients (EH), concentrations of blood glucose, serum INS and serum C - P both during fasting and 2 - hour postprandial time were measured in 32 non-diabetic patients with EH and 40 healthy persons, and the ISI of each group was calculated and compared. The results showed that with the exception of fasting blood glucose level being of no difference between two groups, all the other parameters observed, including concentrations of 2 hour postprandial glucose, both fasting and 2 hour postprandial INS and C - P were significantly higher than those of healthy control group (P < 0.01). The proportions of patients with insulin resistance and hyperinsulinemia in EH group were both significantly higher than those of control group (P < 0.01). These results suggest that EH patients may coexist with some metabolic disorders at the same time, thus INS and C - P detection may have other wider applications in non-diabetic diseases

  12. Value and Payment in Sleep Medicine.

    Science.gov (United States)

    Wickwire, Emerson M; Verma, Tilak

    2018-05-15

    Value, like beauty, exists in the eye of the beholder. This article places the value of clinical sleep medicine services in historical context and presents a vision for the value-based sleep of the future. First, the history of value and payment in sleep medicine is reviewed from the early days of the field, to innovative disruption, to the widespread adoption of home sleep apnea testing. Next, the importance of economic perspective is discussed, with emphasis on cost containment and cost-shifting between payers, employers, providers, and patients. Specific recommendations are made for sleep medicine providers and the field at large to maximize the perceived value of sleep. Finally, alternate payment models and value-based care are presented, with an eye toward the future for clinical service providers as well as integrated health delivery networks. © 2018 American Academy of Sleep Medicine.

  13. Accounting of costs in a service of physical health. Relative units of value in dosimetry clinic in teletherapy

    International Nuclear Information System (INIS)

    Font Gomez, J. A.; Gandia Martinez, A.; Jimenez Albericio, F. J.; Andres Redondon, M. M.; Mengual Gil, M. A.

    2013-01-01

    A single - although laborious - start in the economic and clinical management of our units can be come to the knowledge of the time invested in the tasks functional, having to differentiate them, name them and even encrypt them. The time spent in performing the tasks multiplied by the annual number of these will indicate the resources necessary to achieve our objectives. In addition, pooling the values of times that members of the Unit provide analysed inter-workers dispersal, their causes and possible solutions. The establishment of relative units of value in any process benefits all workers involved in the process since it allows to know the dispersion of the times that each person employed in the development of the tasks. (Author)

  14. Investigation of the added value of high-energy electrons in intensity-modulated radiotherapy: four clinical cases

    International Nuclear Information System (INIS)

    Korevaar, Erik W.; Huizenga, Henk; Loef, Johan; Stroom, Joep C.; Leer, Jan Willem H.; Brahme, Anders

    2002-01-01

    Purpose: Intensity-modulated radiotherapy (IMRT) with photon beams is currently pursued in many clinics. Theoretically, inclusion of intensity- and energy-modulated high-energy electron beams (15-50 MeV) offers additional possibilities to improve radiotherapy treatments of deep-seated tumors. In this study the added value of high-energy electron beams in IMRT treatments was investigated. Methods and Materials: In a comparative treatment planning study, conventional treatment plans and various types of IMRT plans were constructed for four clinical cases (cancer of the bladder, pancreas, chordoma of the sacrum, and breast). The conventional plans were used for the actual treatment of the patients. The IMRT plans were optimized using the Orbit optimization code (Loef et al., 2000) with a radiobiologic objective function. The IMRT plans were either photon or combined electron and photon beam plans, with or without dose homogeneity constraints assuming standard or increased radiosensitivities of organs at risk. Results: Large improvements in expected treatment outcome are found using IMRT plans compared to conventional plans, but differences in tumor control probability (TCP) and normal tissue complication probabilities (NTCP) values between IMRT plans with and without electrons are small. However, the use of electrons improves the dose-volume histograms for organs at risk, especially at lower dose levels (e.g., 0-40 Gy). Conclusions: This preliminary study indicates that addition of higher energy electrons to IMRT can only marginally improve treatment outcome for the selected cases. The dose-volume histograms of organs at risk show improvements for IMRT with higher energy electrons, which may reduce tumor induction but does not substantially reduce NTCP

  15. Somatic aberration induction in Tradescantia occidentalis by neutrons, X- and γ-radiations

    International Nuclear Information System (INIS)

    Dennis, J.A.

    1976-01-01

    Biological results, including statistical features, are described for the irradiation of Tradescantia occidentalis 250 kVp X-rays, cobalt-60 γ-radiation and monoenergetic neutrons with energies between 0.08 and 15 MeV. The effect studied was that of the induction of pink sectors in the otherwide blue staminal hairs of the flowers at low doses of radiation. Statistical aspects of the results suggest that a fraction of the asynchronous cell population in the hairs is very sensitive to neutron radiation, but not necessarily to lower LET radiations. All the results were fitted by a least-squares method by polynominals of different degrees. Best fits to X- and γ-ray data were provided by second-degree polynominals, and to the neutron data by either second- or third-degree polynominals. Limiting r.b.e. and o.e.r. values at low doses are derived. Some computed microdosimetric parameters are presented in comparison with the r.b.e. values. It is concluded that the effect studied is complex and may not provide a critical test of bio-physical theories of radiation effects. (author)

  16. Dose-response relationship for the induction of structural chromosome aberrations in human spermatozoa after in vitro exposure ti tritium. beta. -rays

    Energy Technology Data Exchange (ETDEWEB)

    Kamiguchi, Yujiroh; Tateno, Hiroyuki; Mikamo, Kazuya (Asahikawa Medical College (Japan). Department of Biological Sciences)

    1990-02-01

    THe effects of tritium (HTO) {beta}-rays on human sperm chromosomes were studied using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. Semen samples were treated with media containing 1.53-24.3 mCi/ml HTO for about 80 min. 1290 spermatozoa from the controls and 1842 spermatozoa from the irradiated groups were karyotyped. The incidence of spermatozoa with structural chromosome aberrations increased linearly with increasing dosage. Breakage-type aberrations occurred far more frequently than exchange-type. Chromosome-type aberrations appeared far more frequently than chromatid-ype. All of these types of aberrations showed linear dose-dependent increases. The RBE valus of HTO {beta}-rays relative to X-rays were calculated for the above-mentioned 5 indices, respectively. Their RBE values franged from 1.89 to 3.00 when the absorbed dose was estimated to be the minimum, whereas the values ranged between 1.04 and 1.65 when the absorbed dose was estimated to be the maximum. (author). 15 refs.; 3 figs.; 4 tabs.

  17. The adenoid-nasopharynx ratio. Its clinical value in children

    International Nuclear Information System (INIS)

    Zou Mingshun

    1997-01-01

    To evaluate the clinical usefulness of adenoid-nasopharynx ratio (A/N ratio) measured on nasopharyngeal lateral plain film, 106 clinical cases of secretory otitis media were selected to measure the A/N ratio before treatment. For patients with A/N ratio of 0.50-0.70, the symptoms improved distinctly after conservative treatment, but one half of patients with A/N ratio ≥ 0.71 required adenoidectomy. A/N ratio is a practical and convenient method for evaluation of the adenoid. A/N ratio ≥ 0.71 indicates pathological enlarged adenoid

  18. Genetic variability of genital mycoplasmas and its clinical value

    Directory of Open Access Journals (Sweden)

    K. I. Plakhova

    2015-01-01

    Full Text Available The article presents data on genetic variability of genital mycoplasmas. The author presents the results of genetic variability studies for M. hominis, gene vaa, U. parvum, gene mba, and M. genitalium, gene mg192, sampled from women with different clinical manifestations of inflammatory diseases of the urogenital system. Based on the molecular typing results for 138 samples of genital mycoplasmas, the author revealed a relationship between clinical manifestations of inflammatory diseases of the urogenital system caused by U. parvum and different U. parvum serovars as well as different genetic variations of M. hominis.Infection with 6 U. parvum serovar results in the development of inflammatory diseases of the urogenital tract accompanied by subjective manifestations (р < 0.05. Genetic variant II of М. hominis was revealed more often in patients with clinical manifestations of inflammatory diseases while variant I was revealed more often in patients infected with М. hominis without any signs of inflammation (р < 0.05. Genetic variants of M. genitalium were determined; no significant differences in terms of their prevalence in the examined patients were revealed.

  19. The clinical value of 201Tl per rectum scintigraphy in the work-up of patients with alcoholic liver disease

    International Nuclear Information System (INIS)

    Urbain, D.; Reding, P.; Georges, B.; Thys, O.; Ham, H.R.; Vrije Univ., Brussels

    1986-01-01

    The clinical value of thallium 201 per rectum scintigraphy in the work-up of patients with alcoholic liver disease was evaluated using data obtained in 104 patients. The 25th min ratio of heart to liver activities was used as an index of portal systemic shunting. This ratio was found to be normal in alcoholic patients with normal liver biopsy and also in those presenting only steatosis. It was slightly higher in patients with liver fibrosis and significantly higher values were observed in patients with liver cirrhosis. High values of the ratio were associated with a higher risk of portal systemic encephalopathy and/or gastrointestinal bleeding. The prognostic value of the test was supported by the fact that good correlations were observed between the ratio and widely accepted prognostic scores such as the Child score or the Orrego index. Moreover, high ratios were associated with an increased mortality risk at one year. We conclude that this simple test is interesting in the screening of cirrhotics at risk of encephalopathy, gastrointestinal hemorrhage, or early death. (orig.)

  20. Clinical value of sodium iodide symporter

    International Nuclear Information System (INIS)

    Li Qian

    2003-01-01

    The sodium iodide symptorter (NIS) is a membrane glycoprotein that mediates iodide uptake in the thyroid gland and several extrathyroidal tissues. In addition to thyroid tissues, the expression of NIS is found in stomach, prostate, placenta and so on. Radioiodine-concentrating activity in thyroid tissues has allowed the use of radioiodine as a diagnostic and therapeutic agent for patients with thyroid disorders. However, some extrathyroid tissues also take up radioiodine, contributing to unwanted side effects of radioiodine therapy. Now that the molecule of NIS has been cloned and characterized, it may be possible to develop novel strategies to differentially modulate NIS expression and activity, enhancing it in target tissues and impeding it in others. It is also important to explore the use of NIS as an imaging reporter gene to monitor the expression profile of the transgene in transgenic mouse animal models and in patients undergoing gene therapy clinical trials

  1. Healthcare Practitioners' Personal and Professional Values

    Science.gov (United States)

    Moyo, Mpatisi; Goodyear-Smith, Felicity A.; Weller, Jennifer; Robb, Gillian; Shulruf, Boaz

    2016-01-01

    Personal and professional values of healthcare practitioners influence their clinical decisions. Understanding these values for individuals and across healthcare professions can help improve patient-centred decision-making by individual practitioners and interprofessional teams, respectively. We aimed to identify these values and integrate them…

  2. A phase-I clinical trial for cranial BNCT at Harvard-MIT

    International Nuclear Information System (INIS)

    Busse, P.M.; Palmer, M.R.; Harling, O.K.

    2000-01-01

    Phase I trial designed to determine the maximum tolerable dose to normal tissue for cranial BNCT (Boron Neutron Capture Therapy) irradiations was recently completed at Harvard Medical School and MIT. Twenty-two subjects diagnosed with either glioblastoma multiforme or intracranial melanoma were treated between 1996 and 1999. Subjects received either one or two administrations of boronophenylalanine intravenously at doses between 250 and 350 mg/kg body weight, then exposed in one, two or three fields to epithermal neutrons at the MIT Research Reactor in one or two fractions. Over the course of the study, the maximum normal tissue dose target was increased from 8.8 to 14.2 RBE (Relative Biological Effectiveness) Gy in 10% increments. Subjects have been followed clinically and radiographically. Of those patients surviving beyond six months, no MRI (Magnetic Resonance Image) white-matter changes were observed and no long-term complications attributable to BNCT were evident. Tumor responses were observed, particularly with the melanoma subjects. With increasing doses, difficulties arose from long irradiation times (approximately 3 hours) and the emergence of acute reactions in the skin and mucosa. The trial was stopped in May 1999. Future trials will be initiated with the new high intensity, low background fission converter beam at MIT. (author)

  3. Clinical values of CT and dynamic CT in brain infarction

    International Nuclear Information System (INIS)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul

    1985-01-01

    scan had a marked difference in CT (HU) on absolute scale graph of dynamic CT, so diagnosis of lacunar infarction could be made easily. 7. The clinical values of dynamic CT consist in not only diagnosis of lacunar infarction but also evaluation of effectiveness of medical or surgical treatment

  4. Clinical value of colonic irrigation in patients with continence disturbances.

    Science.gov (United States)

    Briel, J W; Schouten, W R; Vlot, E A; Smits, S; van Kessel, I

    1997-07-01

    Continence disturbances, especially fecal soiling, are difficult to treat. Irrigation of the distal part of the large bowel might be considered as a nonsurgical alternative for patients with impaired continence. This study is aimed at evaluating the clinical value of colonic irrigation. Thirty-two patients (16 females; median age, 47 (range, 23-72) years) were offered colonic irrigation on an ambulatory basis. Sixteen patients suffered from fecal soiling (Group I), whereas the other 16 patients were treated for fecal incontinence (Group II). Patients were instructed by enterostomal therapists how to use a conventional colostomy irrigation set to obtain sufficient irrigation of the distal part of their large bowel. Patients with continence disturbances during the daytime were instructed to introduce 500 to 1,000 ml of warm (38 degrees C) water within 5 to 10 minutes after they passed their first stool. In addition, they were advised to wait until the urge to defecate was felt. Patients with soiling during overnight sleep were advised to irrigate during the evening. To determine clinical outcome, a detailed questionnaire was used. Median duration of follow-up was 18 months. Ten patients discontinued irrigation within the first month of treatment. Symptoms resolved completely in two patients. They believed that there was no need to continue treatment any longer. Irrigation had no effect in two patients. Despite the fact that symptoms resolved, six patients discontinued treatment because they experienced pain (n = 2) or they considered the irrigation to be too time-consuming (n = 4). Twenty-two patients are still performing irrigations. Most patients irrigated the colon in the morning after the first stool was passed. Time needed for washout varied between 10 and 90 minutes. Frequency of irrigations varied from two times per day to two times per week. In Group I, irrigation was found to be beneficial in 92 percent of patients, whereas 60 percent of patients in Group II

  5. Clinical values of CT and dynamic CT in brain infarction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1985-04-15

    -and postcontrast CT scan had a marked difference in CT (HU) on absolute scale graph of dynamic CT, so diagnosis of lacunar infarction could be made easily. 7. The clinical values of dynamic CT consist in not only diagnosis of lacunar infarction but also evaluation of effectiveness of medical or surgical treatment.

  6. Clinical value of serum anti-mullerian hormone and inhibin B in prediction of ovarian response in patients with polycystic ovary syndrome.

    Science.gov (United States)

    Zhang, Fan; Liu, Xiao-Ling; Rong, Nan; Huang, Xiao-Wen

    2017-02-01

    The present study aimed to investigate the clinical value of serum anti-mullerian hormone (AMH) and inhibin B (INHB) in predicting the ovarian response of patients with polycystic ovary syndrome (PCOS). A total of 120 PCOS patients were enrolled and divided into three groups in terms of the ovarian response: a low-response group (n=36), a normal-response group (n=44), and a high-response group (n=40). The serum AMH and INHB levels were measured by enzyme-linked immunosorbent assay (ELISA). The follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) levels were determined by chemiluminescence microparticle immunoassay. The correlation of the serum AMH and INHB levels with other indicators was analyzed. A receiver operating characteristic (ROC) curve was established to analyze the prediction of ovarian response by AMH and INHB. The results showed that there were significant differences in age, body mass index (BMI), FSH, total gonadotropin-releasing hormone (GnRH), LH, E2, and antral follicle counts (AFCs) between the groups (Povarian response of PCOS patients increasing (Povarian response showed that the area under the ROC curve (AUC) value of the serum AMH level was 0.817, with a cut-off value of 1.29 ng/mL. The sensitivity and specificity were 71.2% and 79.6%, respectively. The AUC value of serum INHB was 0.674, with a cut-off value of 38.65 ng/mL, and the sensitivity and specificity were 50.7% and 74.5%, respectively. ROC curve analysis showed when the serum AMH and INHB levels were used to predict a high ovarian response, the AUC value of the serum AMH level was 0.742, with a cut-off value of 2.84 ng/mL, and the sensitivity and specificity were 72.7% and 65.9%, respectively; the AUC value of the serum INHB level was 0.551 with a cut-off of 45.76 ng/mL, and the sensitivity and specificity were 76.3% and 40.2%, respectively. It was suggested the serum AMH and INHB levels have high clinical value in predicting the ovarian response of PCOS

  7. Exploring the value of qualitative research films in clinical education.

    Science.gov (United States)

    Toye, Fran; Jenkins, Sue; Seers, Kate; Barker, Karen

    2015-11-27

    Many healthcare professionals use both quantitative and qualitative research to inform their practice. The usual way to access research findings is through peer-reviewed publications. This study aimed to understand the impact on healthcare professionals of watching and discussing a short research based film. The film, 'Struggling to be me' portrays findings from a qualitative synthesis exploring people's experiences of chronic pain, and was delivered as part of an inter-professional postgraduate e-learning module. The innovation of our study is to be the first to explore the impact of qualitative research portrayed through the medium of film in clinical education. All nineteen healthcare professionals enrolled on the course in December 2013 took part in on-line interviews or focus groups. We recorded and transcribed the interviews verbatim and used the methods of Grounded Theory to analyse the interview transcripts. Watching and discussing the film became a stimulus for learning : (a) A glimpse beneath the surface explored a pro-active way of seeing the person behind the pain (b) Pitfalls of the Medical Model recognised the challenge, for both patient and clinician, of 'sitting with' rather than 'fixing' an ill person; (c) Feeling bombarded by despair acknowledged the intense emotions that the clinicians brings to the clinical encounter; (d) Reconstructing the clinical encounter as a shared journey reconstructed the time-constrained clinical encounter as a single step on a shared journey towards healing, rather than fixing. Films portraying qualitative research findings can stimulate a pro-active and dialectic form of knowing. Research-based qualitative films can make qualitative findings accessible and can be a useful resource in clinical training. Our research presents, for the first time, specific learning themes for clinical education.

  8. Microbial environmental contamination in Italian dental clinics: A multicenter study yielding recommendations for standardized sampling methods and threshold values.

    Science.gov (United States)

    Pasquarella, Cesira; Veronesi, Licia; Napoli, Christian; Castiglia, Paolo; Liguori, Giorgio; Rizzetto, Rolando; Torre, Ida; Righi, Elena; Farruggia, Patrizia; Tesauro, Marina; Torregrossa, Maria V; Montagna, Maria T; Colucci, Maria E; Gallè, Francesca; Masia, Maria D; Strohmenger, Laura; Bergomi, Margherita; Tinteri, Carola; Panico, Manuela; Pennino, Francesca; Cannova, Lucia; Tanzi, Marialuisa

    2012-03-15

    A microbiological environmental investigation was carried out in ten dental clinics in Italy. Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days, for one week per month, for a three-month period. Water and surfaces were sampled before and after clinical activity; air was sampled before, after, and during clinical activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and for the different sampling times. Before clinical activity, microbial water contamination in tap water reached 51,200cfu/mL (colony forming units per milliliter), and that in Dental Unit Water Systems (DUWSs) reached 872,000cfu/mL. After clinical activity, there was a significant decrease in the Total Viable Count (TVC) in tap water and in DUWSs. Pseudomonas aeruginosa was found in 2.38% (7/294) of tap water samples and in 20.06% (59/294) of DUWS samples; Legionella spp. was found in 29.96% (89/297) of tap water samples and 15.82% (47/297) of DUWS samples, with no significant difference between pre- and post-clinical activity. Microbial air contamination was highest during dental treatments, and decreased significantly at the end of the working activity (p<0.05). The microbial buildup on surfaces increased significantly during the working hours. This study provides data for the establishment of standardized sampling methods, and threshold values for contamination monitoring in dentistry. Some very critical situations have been observed which require urgent intervention. Furthermore, the study emphasizes the need for research aimed at defining effective managing strategies for dental clinics. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Assessing the Value of an Optional Radiation Oncology Clinical Rotation During the Core Clerkships in Medical School

    Energy Technology Data Exchange (ETDEWEB)

    Zaorsky, Nicholas G.; Malatesta, Theresa M.; Den, Robert B.; Wuthrick, Evan; Ahn, Peter H.; Werner-Wasik, Maria; Shi, Wenyin; Dicker, Adam P.; Anne, P. Rani; Bar-Ad, Voichita [Department of Radiation Oncology, Jefferson Medical College, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); Showalter, Timothy N., E-mail: timothy.showalter@jeffersonhospital.org [Department of Radiation Oncology, Jefferson Medical College, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

    2012-07-15

    Purpose: Few medical students are given proper clinical training in oncology, much less radiation oncology. We attempted to assess the value of adding a radiation oncology clinical rotation to the medical school curriculum. Methods and Materials: In July 2010, Jefferson Medical College began to offer a 3-week radiation oncology rotation as an elective course for third-year medical students during the core surgical clerkship. During 2010 to 2012, 52 medical students chose to enroll in this rotation. The rotation included outpatient clinics, inpatient consults, didactic sessions, and case-based presentations by the students. Tests of students' knowledge of radiation oncology were administered anonymously before and after the rotation to evaluate the educational effectiveness of the rotation. Students and radiation oncology faculty were given surveys to assess feedback about the rotation. Results: The students' prerotation test scores had an average of 64% (95% confidence interval [CI], 61-66%). The postrotation test scores improved to an average of 82% (95% CI, 80-83%; 18% absolute improvement). In examination question analysis, scores improved in clinical oncology from 63% to 79%, in radiobiology from 70% to 77%, and in medical physics from 62% to 88%. Improvements in all sections but radiobiology were statistically significant. Students rated the usefulness of the rotation as 8.1 (scale 1-9; 95% CI, 7.3-9.0), their understanding of radiation oncology as a result of the rotation as 8.8 (95% CI, 8.5-9.1), and their recommendation of the rotation to a classmate as 8.2 (95% CI, 7.6-9.0). Conclusions: Integrating a radiation oncology clinical rotation into the medical school curriculum improves student knowledge of radiation oncology, including aspects of clinical oncology, radiobiology, and medical physics. The rotation is appreciated by both students and faculty.

  10. Assessing the Value of an Optional Radiation Oncology Clinical Rotation During the Core Clerkships in Medical School

    International Nuclear Information System (INIS)

    Zaorsky, Nicholas G.; Malatesta, Theresa M.; Den, Robert B.; Wuthrick, Evan; Ahn, Peter H.; Werner-Wasik, Maria; Shi, Wenyin; Dicker, Adam P.; Anne, P. Rani; Bar-Ad, Voichita; Showalter, Timothy N.

    2012-01-01

    Purpose: Few medical students are given proper clinical training in oncology, much less radiation oncology. We attempted to assess the value of adding a radiation oncology clinical rotation to the medical school curriculum. Methods and Materials: In July 2010, Jefferson Medical College began to offer a 3-week radiation oncology rotation as an elective course for third-year medical students during the core surgical clerkship. During 2010 to 2012, 52 medical students chose to enroll in this rotation. The rotation included outpatient clinics, inpatient consults, didactic sessions, and case-based presentations by the students. Tests of students’ knowledge of radiation oncology were administered anonymously before and after the rotation to evaluate the educational effectiveness of the rotation. Students and radiation oncology faculty were given surveys to assess feedback about the rotation. Results: The students’ prerotation test scores had an average of 64% (95% confidence interval [CI], 61–66%). The postrotation test scores improved to an average of 82% (95% CI, 80–83%; 18% absolute improvement). In examination question analysis, scores improved in clinical oncology from 63% to 79%, in radiobiology from 70% to 77%, and in medical physics from 62% to 88%. Improvements in all sections but radiobiology were statistically significant. Students rated the usefulness of the rotation as 8.1 (scale 1–9; 95% CI, 7.3–9.0), their understanding of radiation oncology as a result of the rotation as 8.8 (95% CI, 8.5–9.1), and their recommendation of the rotation to a classmate as 8.2 (95% CI, 7.6–9.0). Conclusions: Integrating a radiation oncology clinical rotation into the medical school curriculum improves student knowledge of radiation oncology, including aspects of clinical oncology, radiobiology, and medical physics. The rotation is appreciated by both students and faculty.

  11. Clinical value of FDG-PET/CT in suspected paraneoplastic syndromes: a retrospective analysis of 137 patients

    Energy Technology Data Exchange (ETDEWEB)

    Bjoern Kristensen, Stine; Hess, Soeren; Petersen, Henrik; Hoeilund-Carlsen, Poul Flemming [Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark)

    2015-12-15

    Paraneoplastic syndromes (PNS) are relatively infrequent manifestations appearing before or after a cancer declares itself. Autoimmune mechanisms may be involved, but their cause and pathogenesis are often unknown. Due to disparity of symptoms, PNS remain a major diagnostic challenge. We examined the value of FDG-PET/CT for ruling in or out malignancy in a heterogeneous group of patients with suspected PNS. We retrospectively extracted data from all patients referred 2009-2013 with suspected PNS. Data included age, sex, follow-up period, scan report, further diagnostic procedures, and final clinical diagnosis. Conclusions of the scan reports were compared to the final follow-up outcome as determined during an average follow-up of 31 months (range 6-51.5) in patients who were not diagnosed with cancer in immediate continuation of a positive PET/CT scan. A total of 137 patients were included. Main causes for referral were neurological (n = 67), rheumatological (n = 25), dermatological (n = 18), nephrological (n = 6), haematological (n = 2), abnormal biochemistry (n = 11), and others (n = 8). The cancer prevalence was 8.8 %. The FDG-PET/CT results were as follows: nine true positives, 22 false positives, 103 true negatives, and three false negatives. Corresponding diagnostic values were: sensitivity 75 %, specificity 82 %, accuracy 82 %, and positive and negative predictive values of 29 % and 97 %, respectively. FDG-PET/CT has in patients with suspected PNS an impressively high negative predictive value and may be of value in ruling out PNS, the more so, the more the number of false positives can be minimized or used in differential diagnosis. We believe that FDG-PET/CT may become an important adjunct to the work-up and triage of patients with suspected PNS. (orig.)

  12. What Is the Value of Value-Based Purchasing?

    Science.gov (United States)

    Tanenbaum, Sandra J

    2016-10-01

    Value-based purchasing (VBP) is a widely favored strategy for improving the US health care system. The meaning of value that predominates in VBP schemes is (1) conformance to selected process and/or outcome metrics, and sometimes (2) such conformance at the lowest possible cost. In other words, VBP schemes choose some number of "quality indicators" and financially incent providers to meet them (and not others). Process measures are usually based on clinical science that cannot determine the effects of a process on individual patients or patients with comorbidities, and do not necessarily measure effects that patients value; additionally, there is no provision for different patients valuing different things. Proximate outcome measures may or may not predict distal ones, and the more distal the outcome, the less reliably it can be attributed to health care. Outcome measures may be quite rudimentary, such as mortality rates, or highly contestable: survival or function after prostate surgery? When cost is an element of value-based purchasing, it is the cost to the value-based payer and not to other payers or patients' families. The greatest value of value-based purchasing may not be to patients or even payers, but to policy makers seeking a morally justifiable alternative to politically contested regulatory policies. Copyright © 2016 by Duke University Press.

  13. Clinical value of IS6110-based loop-mediated isothermal amplification for detection of Mycobacterium tuberculosis complex in respiratory specimens.

    Science.gov (United States)

    Aryan, Ehsan; Makvandi, Manoochehr; Farajzadeh, Ahmad; Huygen, Kris; Alvandi, Amir-Hooshang; Gouya, Mohammad-Mehdi; Sadrizadeh, Ali; Romano, Marta

    2013-06-01

    A fundamental to global tuberculosis (TB) control is timely and accurate diagnosis of infectious cases of the disease. Among various methods, techniques based on nucleic acid amplification are the ones with promising prospects. The present study evaluates the diagnostic value of the recently developed IS6110-based loop-mediated isothermal amplification (LAMP) for detection of Mycobacterium tuberculosis complex (MTBC) in sputum specimens. In this cross-sectional study (2008-2009), IS6110-LAMP was evaluated on 101 sputum specimens from 93 highly suspected TB patients and compared to Amplicor MTB test and in-house IS6110-PCR and -nested PCR assays. Culture results or clinical recovery following anti-TB therapy was considered as a reference to prove the TB cases. The overall sensitivity of IS6110-LAMP, Amplicor, nPCR, and PCR were respectively 89.6% (69/77 specimens; 95% confidence interval [CI], 80.5-95.4%), 76.6% (59/77 specimens; CI, 65.6-85.5%), 79.2% (61/77 specimens; CI, 68.5-87.6%) and 59.7% (46/77 specimens; CI, 47.9-70.8%). The specificity and positive predictive value (PPV) were 100% for all the tests, and the negative predictive value (NPV) of IS6110-LAMP, Amplicor, nPCR, and PCR were respectively 75%, 57.1%, 60%, and 43.6%. There was an excellent overall agreement between LAMP and nPCR (k 0.828), and between LAMP and Amplicor (k 0.746), in addition to a better tolerance of IS6110-LAMP to inhibitors present in clinical specimens. The better diagnostic performance of IS6110-LAMP compared to Amplicor (p = 0.009), nPCR (p = 0.013) and PCR (p < 0.0001) besides its rapidity, simplicity, and cost-effectiveness makes it a valuable method for the detection of MTBC in clinical samples, particularly in resource-limited settings. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  14. [Comparison of 2D and 3D sequences for MRCP. Clinical value of the different techniques].

    Science.gov (United States)

    Wallnoefer, A M; Herrmann, K A; Beuers, U; Zech, C J; Gourtsoyianni, S; Reiser, M F; Schoenberg, S O

    2005-11-01

    Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements.

  15. Evaluation of clinical value of combined tumor markers detection in diagnosis of lung cancer

    International Nuclear Information System (INIS)

    Zhang Guangming; Deng Shouzhen; Wang Yun; Xu Lianqin; He Wanting; Gao Quan; Lin Xiangtong

    2002-01-01

    To evaluate clinical value of single or combined tumor marker detection CY21-1, CEA, CA15-3 and SCC in the diagnosis of lung cancer. There was retrospective analysis of 87 lung cancer inpatients, all of them was confirmed by pathology. Results showed: (1) Sensitivity of CY21-1, CEA, CA15-3 and SCC by single detection in diagnosing lung cancer was 59.8%, 39.1%, 44.8%, 18.4%, respectively. (2) Sensitivity of group I (CY21-1 + CEA) was 78.2%; sensitivity of group II (CY21-1 + CEA + CA15-3) was 88.5%; sensitivity of group III (CY21-1 + CEA + CA15-3 + SCC) was the same as group II. In the diagnosis of lung cancer, the combined detection with CY21-1, CEA, CA15-3 was an ideal selective combination

  16. Combining Time-Driven Activity-Based Costing with Clinical Outcome in Cost-Effectiveness Analysis to Measure Value in Treatment of Depression.

    Science.gov (United States)

    El Alaoui, Samir; Lindefors, Nils

    2016-01-01

    A major challenge of mental health care is to provide safe and effective treatment with limited resources. The main purpose of this study was to examine a value-based approach in clinical psychiatry when evaluating a process improvement initiative. This was accomplished by using the relatively new time driven activity based costing (TDABC) method within the more widely adopted cost-effectiveness analysis framework for economic evaluation of healthcare technologies. The objective was to evaluate the cost-effectiveness of allowing psychologists to perform post-treatment assessment previously performed by psychiatrists at an outpatient clinic treating depression using internet-based cognitive-behavioral therapy (ICBT). Data was collected from 568 adult patients treated with ICBT for depression during 2013-2014. The TDABC methodology was used to estimate total healthcare costs, including development of process maps for the complete cycle of care and estimation of resource use and minute costs of staff, hospital space and materials based on their relative proportions used. Clinical outcomes were measured using the Patient Health Questionnaire depression scale (PHQ-9) before and after treatment and at 6-month follow-up. Cost-effectiveness analyses (CEA) was performed and the results presented as incremental net benefits (INB), cost-effectiveness acceptability curves (CEACs) and confidence ellipses to demonstrate uncertainty around the value of the organizational intervention. Taking into account the complete healthcare process (from referral to follow-up assessment), treatment costs decreased from $709 (SD = $130) per patient in 2013 to $659 (SD = $134) in 2014 while treatment effectiveness was maintained; 27% had achieved full remission from depression after treatment (PHQ-9 cost-effectiveness plane at both post-treatment and at follow-up, indicating that the ICBT treatment was less costly and equally effective after staff reallocation. Treating patients to the target

  17. Prognostic value of Ki-67 index in adult medulloblastoma after accounting for molecular subgroup: a retrospective clinical and molecular analysis.

    Science.gov (United States)

    Zhao, Fu; Zhang, Jing; Li, Peng; Zhou, Qiangyi; Zhang, Shun; Zhao, Chi; Wang, Bo; Yang, Zhijun; Li, Chunde; Liu, Pinan

    2018-04-23

    Medulloblastoma (MB) is a rare primary brain tumor in adults. We previously evaluated that combining both clinical and molecular classification could improve current risk stratification for adult MB. In this study, we aimed to identify the prognostic value of Ki-67 index in adult MB. Ki-67 index of 51 primary adult MBs was reassessed using a computer-based image analysis (Image-Pro Plus). All patients were followed up ranging from 12 months up to 15 years. Gene expression profiling and immunochemistry were used to establish the molecular subgroups in adult MB. Combined risk stratification models were designed based on clinical characteristics, molecular classification and Ki-67 index, and identified by multivariable Cox proportional hazards analysis. In our cohort, the mean Ki-67 value was 30.0 ± 11.3% (range 6.56-63.55%). The average Ki-67 value was significantly higher in LC/AMB than in CMB and DNMB (P = .001). Among three molecular subgroups, Group 4-tumors had the highest average Ki-67 value compared with WNT- and SHH-tumors (P = .004). Patients with Ki-67 index large than 30% displayed poorer overall survival (OS) and progression free survival (PFS) than those with Ki-67 less than 30% (OS: P = .001; PFS: P = .006). Ki-67 index (i.e. > 30%, < 30%) was identified as an independent significant prognostic factor (OS: P = .017; PFS: P = .024) by using multivariate Cox proportional hazards model. In conclusion, Ki-67 index can be considered as a valuable independent prognostic biomarker for adult patients with MB.

  18. Modeling the biophysical effects in a carbon beam delivery line by using Monte Carlo simulations

    Science.gov (United States)

    Cho, Ilsung; Yoo, SeungHoon; Cho, Sungho; Kim, Eun Ho; Song, Yongkeun; Shin, Jae-ik; Jung, Won-Gyun

    2016-09-01

    The Relative biological effectiveness (RBE) plays an important role in designing a uniform dose response for ion-beam therapy. In this study, the biological effectiveness of a carbon-ion beam delivery system was investigated using Monte Carlo simulations. A carbon-ion beam delivery line was designed for the Korea Heavy Ion Medical Accelerator (KHIMA) project. The GEANT4 simulation tool kit was used to simulate carbon-ion beam transport into media. An incident energy carbon-ion beam with energy in the range between 220 MeV/u and 290 MeV/u was chosen to generate secondary particles. The microdosimetric-kinetic (MK) model was applied to describe the RBE of 10% survival in human salivary-gland (HSG) cells. The RBE weighted dose was estimated as a function of the penetration depth in the water phantom along the incident beam's direction. A biologically photon-equivalent Spread Out Bragg Peak (SOBP) was designed using the RBE-weighted absorbed dose. Finally, the RBE of mixed beams was predicted as a function of the depth in the water phantom.

  19. Self-assessment of clinical nurse mentors as dimensions of professional development and the capability of developing ethical values at nursing students: A correlational research study.

    Science.gov (United States)

    Skela-Savič, Brigita; Kiger, Alice

    2015-10-01

    Providing adequate training for mentors, fostering a positive mentorship culture and establishing the necessary operational procedures for ensuring mentorship quality are the keys to effective clinical mentoring of nursing students. The purpose of the research was to explain different dimensions of clinical mentors' professional development and their capability of developing ethical values in nursing students. A non-experimental quantitative research design was employed. Data were collected by means of a questionnaire administered to the population of clinical mentors (N=143). The total number of questions was 36. Descriptive statistics were used, and bivariate analysis, factor analysis, correlation analysis and linear regression analysis were performed. The professional development of clinical nurse mentors was explained (R(2)=0.256) by career advancement (p=0.000), research and learning (p=0.024) and having a career development plan (p=0.043). Increased professional self-confidence (R(2)=0.188) was explained by career advancement (p=0.000) and the time engaged in record keeping (p=0.028). Responsibility for the development of ethical values in nursing students (R(2)=0.145) was explained by the respondents' level of education (p=0.020) and research and learning (p=0.024). Applying ethical principles and norms into practice (R(2)=0.212) was explained by self-assessed knowledge in ethics (p=0.037) and research and learning (p=0.044). Clinical nurse mentors tended to lack a career development plan, had low work time spent on research and insufficiently participated in education and training activities, which turned out to be significant explanatory factors of their professional development and their capability of developing ethical values in nursing students. The research showed that nursing and higher education managers often failed to assume responsibility for the professional development of clinical nurse mentors. Copyright © 2015 Elsevier Ltd. All rights

  20. Evaluation of normal tissue responses to high-LET radiations

    International Nuclear Information System (INIS)

    Halnan, K.E.

    1979-01-01

    Clinical results presented have been analysed to evaluate normal tissue responses to high-LET radiations. Damage to brain, spinal cord, gut, skin, connective tissue and bone has occurred. A high RBE is probable for brain and possible for spinal cord and gut but other reasons for damage are also discussed. A net gain seems likely. Random controlled trials are advocated. (author)