Institute Atmospharische Radioaktivitat
Institute Atmospharische Radioaktivitat
Nekolla E.A.,Institute Atmospharische Radioaktivitat
Radiologe | Year: 2017
Background: In Germany, approximately 95% of man-made radiation exposure of the population results from diagnostic and interventional X‑ray procedures. Thus, radiation protection of patients in this field of application is of great importance. Objective: Quantification and evaluation of current data on the frequency and doses of X‑ray procedures as well as temporal trends for the years 2007–2014. Material and methods: For outpatients the frequency of X‑ray procedures was estimated using reimbursement data from health insurances and for inpatients by means of hospital statistics. For the years under review, representative values for the effective dose per X‑ray application were determined mainly from data reported by X‑ray departments to the competent authorities. Results: In 2014 approximately 140 million X‑ray procedures were performed in Germany with some 40% from dental examinations. On average 1.7 procedures per inhabitant and year were almost constantly carried out between 2007 and 2014. Besides dental diagnostics, X‑ray examinations of the skeleton and thorax were performed most frequently. The number of computed tomography (CT) examinations increased by approximately 40%. The increase in magnetic resonance imaging (MRI) was even more pronounced with approximately 55% but overall CT examinations were still performed more often than MRI. The doses per X‑ray procedure were only slightly reduced, despite the various dose reduction approaches established in recent years; therefore, the mean effective dose per inhabitant increased from approximately 1.4 mSv in 2007 to 1.6 mSv in 2014, mainly due to the increasing frequency of CT examinations. Conclusion: The principles of justification and optimization of radiological procedures are to be consistently applied in each individual instance, especially in the case of CT examinations. © 2017 Springer Medizin Verlag GmbH
PubMed | Public Health England, Autonomous University of Barcelona, Helmholtz Center Munich, Ghent University and 8 more.
Type: | Journal: International journal of radiation biology | Year: 2016
Reliable dose estimation is an important factor in appropriate dosimetric triage categorization of exposed individuals to support radiation emergency response.Following work done under the EU FP7 MULTIBIODOSE and RENEB projects, formal methods for defining uncertainties on biological dose estimates are compared using simulated and real data from recent exercises.The results demonstrate that a Bayesian method of uncertainty assessment is the most appropriate, even in the absence of detailed prior information. The relative accuracy and relevance of techniques for calculating uncertainty and combining assay results to produce single dose and uncertainty estimates is further discussed.Finally, it is demonstrated that whatever uncertainty estimation method is employed, ignoring the uncertainty on fast dose assessments can have an important impact on rapid biodosimetric categorization.
PubMed | Federal office of Public Health of Fribourg, University of Bologna, Austrian Agency for Health and Food Safety AGES, Institute for Radiological Protection and Nuclear Safety and 4 more.
Type: | Journal: Journal of environmental radioactivity | Year: 2016
PubMed | Rechtsanwalt und Fachanwalt fur Medizinrecht Torsten Nolling, University of Heidelberg, Universitatsmedizin Mainz, Institute Atmospharische Radioaktivitat and 3 more.
Type: Journal Article | Journal: Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al] | Year: 2016
Application of ionizing radiation for the purpose of medical research in Germany needs to be approved by the national authority for radiation protection (Bundesamt fr Strahlenschutz, BfS). For studies in the field of radiation oncology, differentiation between use of radiation for medical care (Heilkunde) versus medical research frequently leads to contradictions. The aim of this article is to provide principle investigators, individuals, and institutions involved in the process, as well as institutional review or ethics committees, with the necessary information for this assessment. Information on the legal frame and the approval procedures are also provided.A workshop was co-organized by the German Society for Radiation Oncology (DEGRO), the Working Party for Radiation Oncology (ARO) of the German Cancer Society (DKG), the German Society for Medical Physics (DGMP), and the German Cancer Consortium (DKTK) in October 2013. This paper summarizes the results of the workshop and the follow-up discussions between the organizers and the BfS.Differentiating between Heilkunde which does not need to be approved by the BfS and medical research is whether the specific application of radiation (beam quality, dose, schedule, target volume, etc.) is a clinically established and recognized procedure. This must be answered by the qualified physician(s) (fachkundiger Arzt according to German radiation protection law) in charge of the study and the treatments of the patients within the study, taking into consideration of the best available evidence from clinical studies, guidelines and consensus papers. Among the important parameters for assessment are indication, total dose, and fractionation. Radiation treatments applied outside clinical trials do not require approval by the BfS, even if they are applied within a randomized or nonrandomized clinical trial. The decision-making by the fachkundigem Arzt may be supported on request by an opinion given by the DEGRO Expert Committee for clinical trials.An important aim for promoting clinical research and patient care in radiation oncology is to further professionalize planning and implementation of clinical trials in this field. Correct assessment, at an early stage, whether a trial needs to be approved by the BfS may reduce unnecessary costs and reduce the time needed for the approval procedure for those trials which need to be assessed by the BfS.
Brix G.,Federal office for Radiation Protection |
Brix G.,Institute Atmospharische Radioaktivitat |
Griebel J.,Federal office for Radiation Protection |
Kiessling F.,RWTH Aachen |
Wenz F.,University of Mannheim
European Journal of Nuclear Medicine and Molecular Imaging | Year: 2010
Purpose: Technical developments in both magnetic resonance imaging (MRI) and computed tomography (CT) have helped to reduce scan times and expedited the development of dynamic contrast-enhanced (DCE) imaging techniques. Since the temporal change of the image signal following the administration of a diffusible, extracellular contrast agent (CA) is related to the local blood supply and the extravasation of the CA into the interstitial space, DCE imaging can be used to assess tissue microvasculature and microcirculation. It is the aim of this review to summarize the biophysical and tracer kinetic principles underlying this emerging imaging technique offering great potential for non-invasive characterization of tumour angiogenesis. Methods: In the first part, the relevant contrast mechanisms are presented that form the basis to relate signal variations measured by serial CT and MRI to local tissue concentrations of the administered CA. In the second part, the concepts most widely used for tracer kinetic modelling of concentration-time courses derived from measured DCE image data sets are described in a consistent and unified manner to highlight their particular structure and assumptions as well as the relationships among them. Finally, the concepts presented are exemplified by the analysis of representative DCE data as well as discussed with respect to present and future applications in cancer diagnosis and therapy. Results: Depending on the specific protocol used for the acquisition of DCE image data and the particular model applied for tracer kinetic analysis of the derived concentration-time courses, different aspects of tumour angiogenesis can be quantified in terms of well-defined physiological tissue parameters. Conclusions: DCE imaging offers promising prospects for improved tumour diagnosis, individualization of cancer treatment as well as the evaluation of novel therapeutic concepts in preclinical and early-stage clinical trials. © 2010 Springer-Verlag.
Berg H.-P.,Institute Atmospharische Radioaktivitat |
Griebel S.,Siemens AG |
Milius B.,TU Braunschweig
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015
Safety is an important issue for railways as well as nuclear industry. Often, both industries have learned from each other and benefitted from the experience gained in each sector. However, recent research shows the importance to look always at the system as a whole with all its performance shaping aspects. This has to be done before deciding if and under which conditions experience as well as qualitative and quantitative data can be used in the other field. In this paper we will compare the work and its organizational aspects performed by a train controller and by a reactor operator. This will be done using an existing model for a socio-technical system. We show if and how two different jobs and their environments can be compared on a step by step basis. The paper is also an example if and how a generic sociotechnical system can be used for a structured comparison of different systems © 2015 Taylor & Francis Group, London.
Sudbrock F.,University of Cologne |
Uhrhan K.,University of Cologne |
Rimpler A.,Institute Atmospharische Radioaktivitat |
Schicha H.,University of Cologne
Radiation Measurements | Year: 2011
Radiation exposure for the staff in nuclear medicine departments is inevitable. After application of radiopharmaceuticals the patient himself becomes a radioactive source. Consequently, we need detailed information on the extent of radiation exposure for each single person dealing with radioactive sources and patients in nuclear medicine. In this work, dose rates of a variety of radioactive sources - radiopharmaceuticals and patients - in nuclear medicine were investigated. For this purpose different detectors (dosimeters, survey-meters) were used and different sources were measured for several distances between source and detector. The "radioactive patient" as a source can be considered as uncritical. However, this assumption only holds if members of the personnel keep a sufficient distance to the patient of at least 1 m. If treatments in the vicinity of the patient become necessary, the time spent in a closer distance should be limited. The handling of radiopharmaceuticals often involves close contact to the radioactive source. For the β-radiation or in the mixed β,γ-radiation field of several high energy beta emitters ( 32P, 68Ga, 90Y, 188Re) the ambient dose equivalent rate at 10 mm depth together with the directional dose equivalent rate at 0° and 0.07 mm depth have to be determined. Especially for the beta emitters mentioned above these dose rates are very high. For instance the specific dose rate for 90Y yields 4.6 Sv/(GBqh) when dose rate measurements were performed in the closest distance to a glass vial that was practicable. Survey-meters that are only capable of measuring photons fail to provide even a rough approximation of the actual dose rate. Preparations of radiopharmaceuticals with these nuclides may consequently cause a high extremity exposure of laboratory staff. This requires measurements, demands training and a strict compliance with the established radiation safety standards. © 2011 Elsevier Ltd. All rights reserved.
Rimpler A.,Institute Atmospharische Radioaktivitat |
Borst M.,Institute Atmospharische Radioaktivitat |
Seifarth D.,Gesellschaft fur Nuklearservice GNS
Radiation Measurements | Year: 2010
Several types of casks have been deposited in the German interim storage facility for spent fuel assemblies and vitrified high-active waste (HAW) at Gorleben since 1995, most of them of the CASTOR® type. In 2008 a delivery of 11 TN85-type casks arrived. They belong to the Transnuclear/Areva cask family and, compared to the flasks of the German (GNS) CASTOR ® type, they differ in the neutron shielding design. Generally, radiation exposure of personnel during transportation and storage of casks containing spent fuel and vitrified waste is caused by mixed photon/neutron fields. Frequently, especially at casks for vitrified waste from reprocessing, neutrons are the major component of radiation exposure. Spectrometric and dosimetric investigations were made around a cask of the TN85-type. Neutron fluence spectra and reference values of the ambient dose equivalent H (*)(10) were measured by means of a Bonner sphere spectrometer (BSS) at several locations on the cask surface and in its environment. Moreover, commercial area dosemeters, LB6411 neutron monitors and conventional AD 6-type photon dosemeters were used. In addition, the responses of two electronic personal dosemeters for mixed fields (EPD-N2, DMC 2000GN) and a TLD albedo dosemeter were investigated. The neutron spectra obtained from the BSS are presented and compared with former measurements at CASTOR® type casks. The relative responses of the LB6411 survey meter and the individual dosemeters are discussed. The LB6411 monitor indicates H (*)(10) around the TN85 cask with tolerable measuring uncertainties. The personal dosemeters provide acceptable results for photons but overestimate the neutron dose considerably. © 2010 Published by Elsevier Ltd. All rights reserved.
Frieden B.R.,University of Arizona |
Petri M.,Institute Atmospharische Radioaktivitat
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012
Consider a generally closed system of continuous three-space coordinates x with a differentiable amplitude function ψ(x). What is its level of order R? Define R by the property that it decreases (or stays constant) after the system is coarse grained. Then R turns out to obey R=8 -1L2I,where quantity I=4dxψ *• ψ is the classical Fisher information in the system and L is the longest chord that can connect two points on the system surface. In general, order R is (i) unitless, and (ii) invariant to uniform stretch or compression of the system. On this basis, the order R in the Universe was previously found to be invariant in time despite its Hubble expansion, and with value R=26.0×1060 for flat space. By comparison, here we model the Universe as a string-based "holostar," with amplitude function ψ(x) 1/r over radial interval r=(r 0,r H). Here r 0 is of order the Planck length and r H is the radial extension of the holostar, estimated as the known value of the Hubble radius. Curvature of space and relative motion of the observer must now be taken into account. It results that a stationary observer observes a level of order R=(8/9) (r H /r 0 )3 /2=0.42×1090; while for a free-falling observer R=2 -1 (r H /r 0 )2=0.85×10120. Both order values greatly exceed the above flat-space value. Interestingly, they are purely geometric measures, depending solely upon ratio r H/r 0. Remarkably, the free-fall value ∼10120 of R approximates the negentropy of a universe modeled as discrete. This might mean that the Universe contains about equal amounts of continuous and discrete structure. © 2012 American Physical Society.
Berg H.-P.,Institute Atmospharische Radioaktivitat |
Rowekamp M.,GRS Society for plants and Reactor Safety
International Topical Meeting on Probabilistic Safety Assessment and Analysis 2013, PSA 2013 | Year: 2013
The German nuclear regulation has been significantly enhanced recently promulgating stateof-the-art "Safety Requirements to Nuclear Power Plants" published in January 2013. These enhancements also concern safety demonstrations by deterministic as well as probabilistic safety assessment. The update of the regulatory framework does also concern the technical documents on PSA (Probabilistic Safety Analysis) methods and data supplementing the German Guide for probabilistic safety assessment. While PSA was mainly used in Germany in the frame of periodic safety reviews (PSR) in the past, PSA applications as a supplementary analytical tool to be used in the nuclear regulatory framework shall be further extended in the future. In the frame of the Safety Requirements relative probabilistic criteria are being applied for plant or organizational modifications. An expert group has already started an activity to extend the applications of PSA to regulatory issues beyond PSR, such as regulatory oversight on modifications applied by the licensee or evaluation of events or phenomena which have a significant effect on PSA results. The most recent activities with regard to PSA as supplementary tool for safety assessment focus on improvements with respect to low power and shutdown PSA, considering fuel damage states, and in addition covering internal hazards PSA (in particular fire in the scope, providing updates of data for fire protection features. Moreover, clarifications regarding level 2 PSA are provided resulting from the practical application. Further activities aim on applying enhanced methods and providing additional data for human factor analysis using the THERP method. Moreover, a more complete and systematic consideration of external hazards is intended, in particular for seismic events and external flooding. Last not least methods and data for Fire PRA have been improved significantly in the recent past. This shall be clearly reflected in the guidance documents on PSA methods and data as well. The material for the update of methods and data for PSA application in the frame of PSR should be provided until the end of the year in order to issue a supplement to the existing document in 2014.