WorldWideScience

Sample records for radiology hdr erweiterung

  1. Traceable calibration of hospital 192Ir HDR sources

    International Nuclear Information System (INIS)

    Govinda Rajan, K.N.; Sharma, S.D.; Palaniselvam, T.; Vandana, S.; Bhatt, B.C.; Vinatha, S.; Patki, V.S.; Pendse, A.M.; Kannan, V.

    2004-01-01

    A HDR 1000 PLUS well type ionization chamber, procured from Standard Imaging, USA, and maintained by medical Physics and Safety Section (MPSS), Bhabha Atomic Research Centre (BARC), India, as a reference well chamber 1 (RWCH1), was traceably calibrated against the primary standard established by Radiological Standards Laboratory (RSL), BARC for 192 Ir HDR source, in terms of air kerma strength (AKS). An indigenously developed well-type ionization chamber, reference well chamber 2 (RWCH2) and electrometer system, fabricated by CD High Tech (CDHT) Instruments Private Ltd., Bangalore, India, was in turn calibrated against RWCH1. The CDHT system (i.e. RWCH2 and CDHT electrometer system) was taken to several hospitals, in different regions of the country, to check the calibration status of 192 Ir HDR sources. The result of this calibration audit work is reported here. (author)

  2. Erweiterung des QTI-Standards zur Unterstützung von LongMenu-Fragen sowie Abbildung spezifischer Metadaten in QTI 2.1

    Directory of Open Access Journals (Sweden)

    Holzer, Matthias

    2009-02-01

    Full Text Available Anlässlich der Entwicklung einer Prüfungsfragendatenbank wird die Erweiterung des wichtigsten standardisierten Austauschformats für Prüfungsfragen (QTI um einen medizinspezifischen Fragentyp (LongMenu sowie die Verschlagwortung von Prüfungsitems mit medizinspezifischen Klassifikationen beschrieben. Zur standardgemäßen Erweiterung für LongMenu-Fragen wurde die Liste der Antwortoptionen in einer eigenen Datei abgelegt und mittels einer Listen-ID und der ID des Begriffes in dieser Liste aus der QTI-Spezifikation referenziert. Zusätzlich wurde eine Klassifikation nach der „Learning Objects Metadata Specification“ (LOM in den Metadatenbereich des QTI-Datensatzes integriert, der eine Beschreibung des Fragetyps, des Fachgebietes und des Organsystems eines Items erlaubt.

  3. Management of a HDR brachytherapy system in the Hospital Juarez of Mexico; Gestion de un sistema de braquiterapia HDR een el Hospital Juarez de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Serrano F, A.G.; Ramirez R, G.; Gil G, R. [Hospital Juarez de Mexico, Av. l.P.N. 5160, Col. Magdalena de las Salinas, 07760 Mexico D.F. (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria del IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D.F. (Mexico)

    2007-07-01

    Full text: In the Hospital Juarez of Mexico, it is carried out a project to implement a Brachytherapy system with high dose rate (HDR) through a Management quality program. In our work center this treatment modality in patients with cervicouterine cancer is used (CaCu), and constantly it is necessary to carry out improvements in the procedures, with the purpose of optimizing them and in consequence to complete the principles of the Radiological Protection, guaranteeing this way, an attention with the quality and safety, such that allow to diminish the risks to the patients and to assure that the received dose in critical organs it finds inside the permitted therapeutic limits, without commit the radiosensitive response of healthy organs. In this work an analysis of the implementation of this system is presented, detailing the procedures so much in the technological infrastructure like human and indicating the necessary technical and operative requirements to reach an adequate practice in HDR brachytherapy. (Author)

  4. A JPEG backward-compatible HDR image compression

    Science.gov (United States)

    Korshunov, Pavel; Ebrahimi, Touradj

    2012-10-01

    High Dynamic Range (HDR) imaging is expected to become one of the technologies that could shape next generation of consumer digital photography. Manufacturers are rolling out cameras and displays capable of capturing and rendering HDR images. The popularity and full public adoption of HDR content is however hindered by the lack of standards in evaluation of quality, file formats, and compression, as well as large legacy base of Low Dynamic Range (LDR) displays that are unable to render HDR. To facilitate wide spread of HDR usage, the backward compatibility of HDR technology with commonly used legacy image storage, rendering, and compression is necessary. Although many tone-mapping algorithms were developed for generating viewable LDR images from HDR content, there is no consensus on which algorithm to use and under which conditions. This paper, via a series of subjective evaluations, demonstrates the dependency of perceived quality of the tone-mapped LDR images on environmental parameters and image content. Based on the results of subjective tests, it proposes to extend JPEG file format, as the most popular image format, in a backward compatible manner to also deal with HDR pictures. To this end, the paper provides an architecture to achieve such backward compatibility with JPEG and demonstrates efficiency of a simple implementation of this framework when compared to the state of the art HDR image compression.

  5. Improvements of visual X-ray inspection with optimized digital detector technology. Faster and more reliable inspection with High Dynamic Radiology (HDR)

    International Nuclear Information System (INIS)

    Bavendiek, Klaus

    2010-01-01

    Improvements in speed and contrast resolution of Digital Detector Arrays (DDA) and significant higher power of X-Ray tubes in combination with a small focal spot open the door to an improved visual inspection of castings for automotive and aerospace applications. The result is a film-like image quality of castings in a live view. For the new image quality the x-ray parameter have to be optimized in energy and the subject contrast has to be increased to avoid that flaws are covered by the noise in the image. HDR - high dynamic radiology - expands the local contrast in the image and transfers the grey values to the range the human inspector can separate. Due to the movement in the image the inspector gets a glas-like impression of the object and the flaws allowing him to do a decision about the 3D position of a flaw in the object. (orig.)

  6. TU-C-201-00: Clinical Implementation of HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  7. Management of a HDR brachytherapy system in the Hospital Juarez of Mexico

    International Nuclear Information System (INIS)

    Serrano F, A.G.; Ramirez R, G.; Gil G, R.; Azorin N, J.; Rivera M, T.

    2007-01-01

    Full text: In the Hospital Juarez of Mexico, it is carried out a project to implement a Brachytherapy system with high dose rate (HDR) through a Management quality program. In our work center this treatment modality in patients with cervicouterine cancer is used (CaCu), and constantly it is necessary to carry out improvements in the procedures, with the purpose of optimizing them and in consequence to complete the principles of the Radiological Protection, guaranteeing this way, an attention with the quality and safety, such that allow to diminish the risks to the patients and to assure that the received dose in critical organs it finds inside the permitted therapeutic limits, without commit the radiosensitive response of healthy organs. In this work an analysis of the implementation of this system is presented, detailing the procedures so much in the technological infrastructure like human and indicating the necessary technical and operative requirements to reach an adequate practice in HDR brachytherapy. (Author)

  8. Hydrogen dressings HDR

    International Nuclear Information System (INIS)

    Rosiak, J.M.

    1990-01-01

    Within the past several years new developments in biomaterials have enabled a significant progress in the healing of different kinds of wounds. One of such biomaterials is synthetic hydrogels. They can be formed by means of radiation technology which gives some advantages over chemical methods. Hydrogel dressings HDR have the shape of transparent foil, 3-4 mm thick, which contain over 90% water. They can be used for healing exuding wounds and especially burns, ulcers, bedsores and skin grafts. HDR dressings are sterile, transparent and mechanically resistant

  9. MO-B-BRC-02: Ultrasound Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Z. [Duke University Medical Center (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  10. MO-B-BRC-02: Ultrasound Based Prostate HDR

    International Nuclear Information System (INIS)

    Chang, Z.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  11. MO-B-BRC-04: MRI-Based Prostate HDR

    International Nuclear Information System (INIS)

    Mourtada, F.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  12. MO-B-BRC-03: CT-Based Prostate HDR

    International Nuclear Information System (INIS)

    Zoberi, J.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  13. MO-B-BRC-04: MRI-Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Mourtada, F. [Christiana Care Hospital (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  14. MO-B-BRC-03: CT-Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Zoberi, J. [Washington University School of Medicine (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  15. HDR Efex Pro After the Shoot

    CERN Document Server

    Sholik, Stan

    2011-01-01

    A concise, on-the-go guide to the new HDR Efex Pro imaging toolkit for photographers Now that you've gone mobile and HDR, you want to be able to download and enhance your favorite photos on the run, without having to return to the mother ship (i.e., your desktop computer). This book shows you just how to do that using the amazing HDR Efex Pro, the image editing toolset from Nik Software. In brilliant color and using plenty of show-stopping examples, this practical guide explains all tools and features. Follow numbered steps and you'll soon be handling things like alignment, ghosting control, h

  16. HDR economy with special reference to conditions in Europe

    International Nuclear Information System (INIS)

    Smolka, K.; Kappelmeyer, O.

    1992-01-01

    A cost benefit model for the economic evaluation of HDR energy production cost was developed. It can be used for systematic cost analyses of different components of a HDR plant. This relates to natural subsurface conditions (i.e., geothermal gradient, tectonic stress) as well as technical components (i.e., boreholes, heat/power conversion system). The model provides the limiting conditions for an economic HDR energy production. The economic model was applied for an evaluation of the natural parameters in the subsurface of Germany regarding their HDR-suitability. Within a site selection program in Europe the model is part of feasibility studies for the conceptual design of a HDR demonstration plant at three candidate sites: Bad Urach (Germany); Soultz-sous-Forets (France) and Cornwall (UK)

  17. TU-C-201-02: Clinical Implementation of HDR: Afterloader and Applicator Selection

    Energy Technology Data Exchange (ETDEWEB)

    Esthappan, J. [Washington University School of Medicine (United States)

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  18. Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Korb, Leroy J.; Darnell, Brenda; Krishna, K. V.; Ulewicz, Dennis

    1998-01-01

    Purpose: An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically. Methods and Materials: In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year. Results: In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%. Conclusion: An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type

  19. MR-based source localization for MR-guided HDR brachytherapy

    Science.gov (United States)

    Beld, E.; Moerland, M. A.; Zijlstra, F.; Viergever, M. A.; Lagendijk, J. J. W.; Seevinck, P. R.

    2018-04-01

    For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4–0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15–1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.

  20. Viewpoint adaptive display of HDR images

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Mantel, Claire

    2017-01-01

    In this paper viewpoint adaptive display of HDR images incorporating the effects of ambient light is presented and evaluated. LED backlight displays may render HDR images, but while at a global scale a high dynamic range may be achieved, locally the contrast is limited by the leakage of light...... through the LC elements of the display. To render high quality images, the display with backlight dimming can compute the values of the LED backlight and LC elements based on the input image, information about the viewpoint of the observer(s) and information of the ambient light. The goal is to achieve...... the best perceptual reproduction of the specified target image derived from the HDR input image in the specific viewing situation including multiple viewers, possibly having different preferences. An optimization based approach is presented. Some tests with reproduced images are also evaluated subjectively...

  1. HDR video synthesis for vision systems in dynamic scenes

    Science.gov (United States)

    Shopovska, Ivana; Jovanov, Ljubomir; Goossens, Bart; Philips, Wilfried

    2016-09-01

    High dynamic range (HDR) image generation from a number of differently exposed low dynamic range (LDR) images has been extensively explored in the past few decades, and as a result of these efforts a large number of HDR synthesis methods have been proposed. Since HDR images are synthesized by combining well-exposed regions of the input images, one of the main challenges is dealing with camera or object motion. In this paper we propose a method for the synthesis of HDR video from a single camera using multiple, differently exposed video frames, with circularly alternating exposure times. One of the potential applications of the system is in driver assistance systems and autonomous vehicles, involving significant camera and object movement, non- uniform and temporally varying illumination, and the requirement of real-time performance. To achieve these goals simultaneously, we propose a HDR synthesis approach based on weighted averaging of aligned radiance maps. The computational complexity of high-quality optical flow methods for motion compensation is still pro- hibitively high for real-time applications. Instead, we rely on more efficient global projective transformations to solve camera movement, while moving objects are detected by thresholding the differences between the trans- formed and brightness adapted images in the set. To attain temporal consistency of the camera motion in the consecutive HDR frames, the parameters of the perspective transformation are stabilized over time by means of computationally efficient temporal filtering. We evaluated our results on several reference HDR videos, on synthetic scenes, and using 14-bit raw images taken with a standard camera.

  2. Performance evaluation of objective quality metrics for HDR image compression

    Science.gov (United States)

    Valenzise, Giuseppe; De Simone, Francesca; Lauga, Paul; Dufaux, Frederic

    2014-09-01

    Due to the much larger luminance and contrast characteristics of high dynamic range (HDR) images, well-known objective quality metrics, widely used for the assessment of low dynamic range (LDR) content, cannot be directly applied to HDR images in order to predict their perceptual fidelity. To overcome this limitation, advanced fidelity metrics, such as the HDR-VDP, have been proposed to accurately predict visually significant differences. However, their complex calibration may make them difficult to use in practice. A simpler approach consists in computing arithmetic or structural fidelity metrics, such as PSNR and SSIM, on perceptually encoded luminance values but the performance of quality prediction in this case has not been clearly studied. In this paper, we aim at providing a better comprehension of the limits and the potentialities of this approach, by means of a subjective study. We compare the performance of HDR-VDP to that of PSNR and SSIM computed on perceptually encoded luminance values, when considering compressed HDR images. Our results show that these simpler metrics can be effectively employed to assess image fidelity for applications such as HDR image compression.

  3. Traceable calibration of hospital 192Ir HDR sources

    International Nuclear Information System (INIS)

    Govinda Rajan, K.N.; Bhatt, B.C.; Pendse, A.M.; Kannan, V.

    2002-01-01

    Presently, no primary standard exists for the standardization of remote afterloading 192 Ir HDR sources. These sources are, therefore, being standardized by a few Secondary Standard Dosimetry Laboratories (SSDLs), in terms of Air Kerma Strength (AKS) or Reference Air Kerma Rate (RAKR) using a 0.6 cc Farmer type chamber, set up as an Interim Standard. These SSDLs offer calibration to well type of ionization chambers that are normally used by the hospitals for calibrating the 192 lr HDR source. Presently, in many countries, including India, well chambers are not commercially available. Nor do these countries offer any calibration service for 192 lr HDR source. With the result users make use of well chambers imported from different countries with their calibration traceable to the country of origin. Since no intercomparisons between these countries have been reported, the measurement consistency between hospitals becomes questionable. The problem is compounded by the fact that these chambers are used for several years without re-calibration since no calibration service is locally available. For instance, in India, the chambers have been in use in hospitals, since 1994, without a second calibration. Not all hospitals use the well chamber for the calibration of the 192 lr HDR source. Many hospitals make use of 0.6 cc chambers, in air, at short source to chamber distances, for measuring the AKS of the source. The latter method is prone to much larger inaccuracy due to the use of very short source to chamber distances without proper calibration jigs, use of 60 Co calibration factor for 192 Ir HDR source calibrations, neglecting correction factors for room scatter, fluence non-uniformity, use of arbitrary buildup factors for the buildup cap of the chamber etc. A comparison of the procedures used at hospitals revealed that various arbitrary methods are in use at hospitals. An indigenously developed well chamber was calibrated against a Reference Standard traceable to the

  4. HDR Image Quality Enhancement Based on Spatially Variant Retinal Response

    Directory of Open Access Journals (Sweden)

    Horiuchi Takahiko

    2010-01-01

    Full Text Available There is a growing demand for being able to display high dynamic range (HDR images on low dynamic range (LDR devices. Tone mapping is a process for enhancing HDR image quality on an LDR device by converting the tonal values of the original image from HDR to LDR. This paper proposes a new tone mapping algorithm for enhancing image quality by deriving a spatially-variant operator for imitating S-potential response in human retina, which efficiently improves local contrasts while conserving good global appearance. The proposed tone mapping operator is studied from a system construction point of view. It is found that the operator is regarded as a natural extension of the Retinex algorithm by adding a global adaptation process to the local adaptation. The feasibility of the proposed algorithm is examined in detail on experiments using standard HDR images and real HDR scene images, comparing with conventional tone mapping algorithms.

  5. Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

    International Nuclear Information System (INIS)

    Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

    2004-01-01

    A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

  6. Color sensitivity of the multi-exposure HDR imaging process

    Science.gov (United States)

    Lenseigne, Boris; Jacobs, Valéry Ann; Withouck, Martijn; Hanselaer, Peter; Jonker, Pieter P.

    2013-04-01

    Multi-exposure high dynamic range(HDR) imaging builds HDR radiance maps by stitching together different views of a same scene with varying exposures. Practically, this process involves converting raw sensor data into low dynamic range (LDR) images, estimate the camera response curves, and use them in order to recover the irradiance for every pixel. During the export, applying white balance settings and image stitching, which both have an influence on the color balance in the final image. In this paper, we use a calibrated quasi-monochromatic light source, an integrating sphere, and a spectrograph in order to evaluate and compare the average spectral response of the image sensor. We finally draw some conclusion about the color consistency of HDR imaging and the additional steps necessary to use multi-exposure HDR imaging as a tool to measure the physical quantities such as radiance and luminance.

  7. Guidelines for optimization of planar HDR implants

    International Nuclear Information System (INIS)

    Zwicker, R.D.; Schmidt-Ullrich, R.

    1996-01-01

    Purpose: Conventional low dose rate (LDR) planar Ir-192 implants are typically carried out using at most a few different source strengths. Remote afterloading offers a much higher degree of flexibility with individually programmable dwell times. Dedicated software is available to generate individual dwell times producing isodose surfaces which contour as closely as possible the target volume. The success of these algorithms in enclosing the target volume while sparing normal tissues is dependent on the positioning of the source guides which constrain the dwell points. In this work we provide source placement guidelines for optimal coverage and dose uniformity in planar high dose rate (HDR) implants. The resulting distributions are compared with LDR treatments in terms of dose uniformity and early and late tissue effects. Materials and methods: Computer studies were undertaken to determine source positions and dwell times for optimal dose uniformity in planar HDR implants, and the results were compared to those obtained using corresponding LDR implant geometries. The improvements in the dose distributions achieved with the remote after loader are expected to help offset the increased late tissue effects which can occur when LDR irradiation is replaced with a few large HDR fractions. Equivalent differential volume-dose (DVD) curves for early and late effects were calculated for different numbers of HDR fractions using a linear-quadratic model and compared to the corresponding curves for the LDR regime. Results: Tables of source placement parameters were generated as guidelines for achieving highly homogeneous planar HDR dose distributions. Differential volume-dose data generated inside the target volume provide a quantitative measure of the improvement in real dose homogeneity obtained with remote afterloading. The net result is a shift of the peak in the DVD curve toward lower doses relative to the LDR implant. The equivalent DVD curves for late effects obtained

  8. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    International Nuclear Information System (INIS)

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  9. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  10. HDR-Clinical Data Service (CDS)

    Data.gov (United States)

    Department of Veterans Affairs — CDS is a SOAP/REST web service interface that supports Create, Retrieve, Update, and Delete (CRUD) operations against HDR data stores over secure Hypertext Transfer...

  11. Evaluating HDR photos using Web 2.0 technology

    Science.gov (United States)

    Qiu, Guoping; Mei, Yujie; Duan, Jiang

    2011-01-01

    High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative

  12. Occurrence Prospect of HDR and Target Site Selection Study in Southeastern of China

    Science.gov (United States)

    Lin, W.; Gan, H.

    2017-12-01

    Hot dry rock (HDR) geothermal resource is one of the most important clean energy in future. Site selection a HDR resource is a fundamental work to explore the HDR resources. This paper compiled all the HDR development projects domestic and abroad, and summarized the location of HDR geothermal geological index. After comparing the geological background of HDR in the southeast coastal area of China, Yangjiang Xinzhou in Guangdong province, Leizhou Peninsula area, Lingshui in Hainan province and Huangshadong in Guangzhou were selected from some key potential target area along the southeast coast of China. Deep geothermal field model of the study area is established based on the comprehensive analysis of the target area of deep geothermal geological background and deep thermal anomalies. This paper also compared the hot dry rock resources target locations, and proposed suggestions for the priority exploration target area and exploration scheme.

  13. TU-C-201-01: Clinical Implementation of HDR: A New User’s Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hallaq, H. [The University of Chicago (United States)

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  14. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of High-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Erickson, Beth A.; Demanes, D. Jeffrey; Ibbott, Geoffrey S.; Hayes, John K.; Hsu, I-Chow J.; Morris, David E.; Rabinovitch, Rachel A.; Tward, Jonathan D.; Rosenthal, Seth A.

    2011-01-01

    High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program.

  15. SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J [Purdue University, West Lafayette, IN (United States); Wu, H [IUPUI, Indianapolis, IN (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boost combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.

  16. Simultaneous radiochemotherapy and endoluminal HDR brachytherapy in esophageal cancer; Simultane Radiochemotherapie mit intraluminaler HDR-Brachytherapie des Oesophaguskarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Patonay, P.; Naszaly, A.; Mayer, A. [Hauptstaedtisches Zentrum fuer Radioonkologie und Strahlentherapie, Budapest (Hungary)

    2007-02-15

    Purpose: to study efficacy and toxicity of radiochemotherapy in esophageal cancer including initial endoluminal high-dose-rate brachytherapy (HDR-BT). Patients and methods: between 01/1995 and 06/2005, 61 patients with esophageal cancer were treated preoperatively with definitive and palliative intent. Treatment started with intraluminal HDR-BT for recanalization of the esophagus (single fraction size of 8 Gy in 0.5 cm depth, three times, q7d) followed by external-beam radiation therapy (50 Gy total dose, 5 x 2 Gy/week, 25 fractions in 5 weeks). Chemotherapy was started simultaneously with external irradiation (three courses of cisplatin and 5-fluorouracil, q21d). Results: swallowing function improved in 55/61 patients (dysphagia classification according to the RTOG), and worsened in 6/61 patients, respectively. Median duration of symptomatic improvement was 11 months, median follow-up 12 months (range 3-68 months). Following simultaneous radiochemotherapy, tumor resectability was achieved in 7/25 patients of the neoadjuvant group, and the histological specimen showed complete remission in 6/7 patients. Conclusion: these results indicate a favorable effect of simultaneous radiochemotherapy starting with endoluminal HDR-after-loading-(AL-)BT in esophageal cancer. (orig.)

  17. Radiobiological considerations in gynaecological HDR and LDR brachytherapy

    International Nuclear Information System (INIS)

    Bauer, M.; Schulz-Wendtland, R.

    1989-01-01

    In brachytherapy the advantages of high dose rate over low dose rate afterloading therapy were obvious. Out-patient treatment becomes possible, the position of the sources is reproducible and can be observed during the treatment and the patients have to be immobilised for only a short time, giving less psychological stress and a decreased risk of thrombosis and embolism. When changing from LDR to HDR afterloading therapy we are not yet able to evaluate its biological impact. Radiobiological considerations and our experimental data, however, give us the following clinical consequences by using HDR brachytherapy: There is a need for about 15 fractions or more and each increase in dose rate requires higher fractioning. Due to the steep dose rate decline and the inhomogeneous dose distribution, multiple equivalence factors are necessary when fractioning is not sufficiently high. Correction factors to reduce the dose close to the source are low, with increasing distance from the source they increase. If HDR radiation therapy is used, the percutaneous dose in the pelvic wall region should be reduced. The reduction of the dose in HDR brachytherapy is a compromise to limit the side effects caused by the radiation. The drawback is a small therapeutic range and reduced therapeutic effectivity at the tumour. (orig.) [de

  18. Dose rate considerations in brachytherapy: biological equivalence of LDR and HDR

    International Nuclear Information System (INIS)

    Orton, C.G.

    1994-01-01

    The linear-quadratic model for cell survival and bioeffect doses is discussed and equations for low dose rate (LDR), high dose rate (HDR) and intermediate situations are presented. The model, when used to define LDR and single fractions of HDR, shows, that these correspond to irradiations lasting longer than about 14 hours or shorter than about 0.7 hours, respectively. It is shown that, for HDR to be as safe and effective as LDR, the dose-rate effect of LDR has to be replaced by the fractionation-effect of HDR. This is necessary in order to take advantage of the differential repair characteristics between late-reacting normal tissue and tumor cells at low doses and low dose rates. Using the linear-quadratic model to simulate repair mathematically, it is shown that the number of fractions required is highly dependent upon what parameters are assumed for normal tissues and tumor, as well as whether or not there is any physical advantage gained by conversion from LDR to HDR. (author). 20 refs., 7 figs

  19. HDR-Aggregate Read Service (ARS)

    Data.gov (United States)

    Department of Veterans Affairs — ARS is a SOAP web service exposed over HTTPS that provides an aggregated (report) view of HTH Survey, DMP and Census data stored in the HDR DB. ARS is deployed in...

  20. An Eight-Year Experience of HDR Brachytherapy Boost for Localized Prostate Cancer: Biopsy and PSA Outcome

    International Nuclear Information System (INIS)

    Bachand, Francois; Martin, Andre-Guy; Beaulieu, Luc; Harel, Francois M.Sc.; Vigneault, Eric

    2009-01-01

    Purpose: To evaluate the biochemical recurrence-free survival (bRFS), the 2-year biopsy outcome and the prostate-specific antigen (PSA) bounce in patients with localized prostate cancer treated with an inversely planned high-dose-rate (HDR) brachytherapy boost. Materials and methods: Data were collected from 153 patients treated between 1999 and 2006 with external beam pelvic radiation followed by an HDR Ir-192 prostate boost. These patients were given a boost of 18 to 20 Gy using inverse-planning with simulated annealing (IPSA).We reviewed and analyzed all prostate-specific antigen levels and control biopsies. Results: The median follow-up was 44 months (18-95 months). When categorized by risk of progression, 74.5% of patients presented an intermediate risk and 14.4% a high one. Prostate biopsies at 2 years posttreatment were negative in 86 of 94 patients (91.5%), whereas two biopsies were inconclusive. Biochemical control at 60 months was at 96% according to the American Society for Therapeutic Radiology and Oncology and the Phoenix consensus definitions. A PSA bounce (PSA values of 2 ng/mL or more above nadir) was observed in 15 patients of 123 (9.8%). The median time to bounce was 15.2 months (interquartile range, 11.0-17.7) and the median bounce duration 18.7 months (interquartile range, 12.1-29). The estimate of overall survival at 60 months was 97.1% (95% CI, 91.6-103%). Conclusions: Considering that inverse planned HDR brachytherapy prostate boosts led to an excellent biochemical response, with a 2-year negative biopsy rate, we recommend a conservative approach in face of a PSA bounce even though it was observed in 10% of patients

  1. SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

    International Nuclear Information System (INIS)

    Joseph, F Maria; Podder, T; Yu, Y

    2015-01-01

    Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostate HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system

  2. Development of optimized dosimetric models for HDR brachytherapy

    International Nuclear Information System (INIS)

    Thayalan, K.; Jagadeesan, M.

    2003-01-01

    High dose rate brachytherapy (HDRB) systems are in clinical use for more than four decades particularly in cervical cancer. Optimization is the method to produce dose distribution which assures that doses are not compromised at the treatment sites whilst reducing the risk of overdosing critical organs. Hence HDRB optimization begins with the desired dose distribution and requires the calculations of the relative weighting factors for each dwell position with out changing the source activity. The optimization for Ca. uterine cervix treatment is simply duplication of the dose distribution used for Low dose rate (LDR) applications. In the present work, two optimized dosimetric models were proposed and studied thoroughly, to suit the local clinical conditions. These models are named as HDR-C and HDR-D, where C and D represent configuration and distance respectively. These models duplicate exactly the LDR pear shaped dose distribution, which is a golden standard. The validity of these models is tested in different clinical situations and in actual patients (n=92). These models: HDR-C and HDR-D reduce bladder dose by 11.11% and 10% and rectal dose by 8% and 7% respectively. The treatment time is also reduced by 12-14%. In a busy hospital setup, these models find a place to cater large number of patients, while addressing individual patients geometry. (author)

  3. Robust Estimation of HDR in fMRI using H-infinity Filters

    DEFF Research Database (Denmark)

    Puthusserypady, Sadasivan; Jue, R.; Ratnarajah, T.

    2010-01-01

    Estimation and detection of the hemodynamic response (HDR) are of great importance in functional MRI (fMRI) data analysis. In this paper, we propose the use of three H-infinity adaptive filters (finite memory, exponentially weighted, and timevarying) for accurate estimation and detection of the HDR......-1487]. Performances of the proposed techniques are compared to the conventional t-test method as well as the well-known LMSs and recursive least squares algorithms. Extensive numerical simulations show that the proposed methods result in better HDR estimations and activation detections....

  4. Coexistence Mechanism for Colocated HDR/LDR WPANs Air Interfaces

    Directory of Open Access Journals (Sweden)

    Prasad Ramjee

    2010-01-01

    Full Text Available This paper addresses the issues of interference management among Low Data Rate (LDR and High Data Rate (HDR WPAN air interfaces that are located in close-proximity (up to 10 cm and eventually on the same multimode device. After showing the noticeable performance degradation in terms of Bit Error Rate (BER and goodput due to the out-of-band interference of an HDR air interface over an LDR air interface, the paper presents a novel coexistence mechanism, named Alternating Wireless Activity (AWA, which is shown to greatly improve the performance in terms of goodput of the most interference vulnerable air interface (i.e., the LDR air interface. The main difference of the proposed mechanism with respect to other collaborative mechanisms based on time-scheduling is that it synchronizes the transmission of the LDR and HDR WPANs at the superframe level instead of packet level. Advantages and limitations of this choice are presented in the paper. Furthermore the functionalities of the AWA mechanism are positioned in a common protocol layer over the Medium Access Control (MAC sublayers of the HDR and LDR devices and it can be used with any standard whose MAC is based on a superframe structure.

  5. Cost modelling of electricity producing hot dry rock (HDR) geothermal systems in the UK

    International Nuclear Information System (INIS)

    Doherty, P.S.

    1992-03-01

    A detailed and comprehensive cost model for Hot Dry Rock (HDR) electricity producing systems has been developed in this study. The model takes account of the major aspects of the HDR system, parameterized in terms of the main physical and cost parameters of the resource and the utilization system. A doublet configuration is assumed, and the conceptual HDR system which is defined in the study is based upon the UK Department of Energy (DEn) HDR geothermal R and D programme. The model has been used to calculate the costs of HDR electricity for a UK defined base case which represents a consensus view of what might be achieved in Cornwall in the long term. At 14.2 p/kWh (1988 costs) this cost appears to be unacceptably high. A wide-ranging sensitivity study has also been carried out on the main resource, geometrical, and operational parameters of the HDR system centred around the UK base case. The sensitivity study shows the most important parameters to be thermal gradient and depth. (Author)

  6. Cost modelling of electricity-producing hot dry rock (HDR) geothermal systems in the United Kingdom

    International Nuclear Information System (INIS)

    Doherty, P.; Harrison, R.

    1995-01-01

    A detailed and comprehensive cost model for Hot Dry Rock (HDR) electricity producing systems has been developed in this study. The model takes account of the major aspects of the HDR system, parameterized in terms of the main physical and cost parameters of the resource and the utilization system. A doublet configuration is assumed, and the conceptual HDR system which is defined in the study is based upon the UK Department of Energy (DEn) HDR geothermal R and D programme. The model has been used to calculate the costs of HDR electricity for a UK defined base case which represents a consensus view of what might be achieved in Cornwall in the long term. At 14.2 p/kWh (1988 costs) this cost appears to be unacceptably high. A wide-ranging sensitivity study has also been carried out on the main resource, geometrical, and operational parameters of the HDR system centred around the UK base case. The sensitivity study shows the most important parameters to be thermal gradient and depth. The geometrical arrangement and the shape of the reservoir constitute major uncertainties in HDR systems. Their effect on temperature has a major influence on system performance, and therefore a range of theoretically possible geometries have been studied and the importance of geometrical effects on HDR electricity costs assessed. The most cost effective HDR arrangement in terms of optimized volumes and flow rates has been investigated for a world-wide range of thermal settings. The main conclusions from this study suggests that for HDR electricity to be economic, thermal gradients of 55 o C/km and above, well depths of 5 km or less, and production fluid temperatures of 210 o C and above are required. (UK)

  7. HDR ühest kaadrist? / Janno Loide

    Index Scriptorium Estoniae

    Loide, Janno

    2008-01-01

    HDR-töötluse (High dynamic range - pildi kõrge dünaamiline ulatus) ja toonide kohandamise (tone mapping) meetodite kasutamisest pildi digitaalsel salvestusel ning sobiva hele-tumeduse leidmisel loodusfotode parema kvaliteedi saamiseks

  8. A dosimetric selectivity intercomparison of HDR brachytherapy, IMRT and helical tomotherapy in prostate cancer radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hermesse, Johanne; Biver, Sylvie; Jansen, Nicolas; Coucke, Philippe [Dept. of Radiation Oncology, Liege Univ. Hospital (Belgium); Lenaerts, Eric [Dept. of Medical Physics, Liege Univ. Hospital (Belgium); De Patoul, Nathalie; Vynckier, Stefaan [Dept. of Medical Physics, St Luc Univ. Hospital, Brussels (Belgium); Scalliet, Pierre [Dept. of Radiation Oncology, St Luc Univ. Hospital, Brussels (Belgium); Nickers, Philippe [Dept. of Radiation Oncology, Oscar Lambret Center, Lille (France)

    2009-11-15

    Background and purpose: dose escalation in order to improve the biochemical control in prostate cancer requires the application of irradiation techniques with high conformality. The dosimetric selectivity of three radiation modalities is compared: high-dose-rate brachytherapy (HDR-BT), intensity-modulated radiation radiotherapy (IMRT), and helical tomotherapy (HT). Patients and methods: ten patients with prostate adenocarcinoma treated by a 10-Gy HDR-BT boost after external-beam radiotherapy were investigated. For each patient, HDR-BT, IMRT and HT theoretical treatment plans were realized using common contour sets. A 10-Gy dose was prescribed to the planning target volume (PTV). The PTVs and critical organs' dose-volume histograms obtained were compared using Student's t-test. Results: HDR-BT delivers spontaneously higher mean doses to the PTV with smaller cold spots compared to IMRT and HT. 33% of the rectal volume received a mean HDR-BT dose of 3.86 {+-} 0.3 Gy in comparison with a mean IMRT dose of 6.57 {+-} 0.68 Gy and a mean HT dose of 5.58 {+-} 0.71 Gy (p < 0.0001). HDR-BT also enables to better spare the bladder. The hot spots inside the urethra are greater with HDR-BT. The volume of healthy tissue receiving 10% of the prescribed dose is reduced at least by a factor of 8 with HDR-BT (p < 0.0001). Conclusion: HDR-BT offers better conformality in comparison with HT and IMRT and reduces the volume of healthy tissue receiving a low dose. (orig.)

  9. Preliminary results of study comparing HDR with LDR brachytherapy for IIIb cervical cancer

    International Nuclear Information System (INIS)

    Trippe, N.; Pellizzon, A.C.A.; Novaes, P.; Salvajoli, J.V.; Fogaroli, R.; Maia, M.A.C.; Baraldi, H.; Ferrigno, R.

    1996-01-01

    Since 1992 we have been using a Micro-Selectron HDR device, working with Iridium 192 to treat the cervical cancer and some others pathologies. With a minimum follow up of 24 months, 59 patients with cervical cancer were randomizated for one of the following schedule of treatment: EBRT - 45Gy - fx 1,8Gy plus Brachytherapy 1-HDR - 36 (61%) - 4 weekly insertions of 6,0Gy at point A 2-LDR - 29 (39%) - two insertions fifteen days apart of 17,5Gy at point A EBRT was performed with a Linac 4MV, in box arrangement and parametrial complementation of dose with AP-PA fields. For Brachytherapy Fletcher Colpostats are used in association with intrauterine tamdens, in both arms. Brachyterapy starts in HDR group after ten days of the beginning of the treatment. The total time of treatment is shortened here in two weeks. LDR brachytherapy starts only after the end of EBRT. Results - local control was 61% in 12 months and 50% in 24 months for HDR group, versus 52,6% and 47,8% for LDR group. Local failures of 39% and 50% in 12 and 24 months for HDR and 47,8% and 52,8% for LDR groups respectively. Complications were restricted to rectites and cistites - 8,3% for HDR and 13% for LDR. Conclusions - HDR brachytherapy has an equivalent local control when compared to LDR, can treat a larger number of patients in a shorter period, has possibilities of dose optimizations and decrease the radiation exposure to the staff

  10. LDR vs. HDR brachytherapy for localized prostate cancer: the view from radiobiological models.

    Science.gov (United States)

    King, Christopher R

    2002-01-01

    Permanent LDR brachytherapy and temporary HDR brachytherapy are competitive techniques for clinically localized prostate radiotherapy. Although a randomized trial will likely never be conducted comparing these two forms of brachytherapy, a comparative radiobiological modeling analysis proves useful in understanding some of their intrinsic differences, several of which could be exploited to improve outcomes. Radiobiological models based upon the linear quadratic equations are presented for fractionated external beam, fractionated (192)Ir HDR brachytherapy, and (125)I and (103)Pd LDR brachytherapy. These models incorporate the dose heterogeneities present in brachytherapy based upon patient-derived dose volume histograms (DVH) as well as tumor doubling times and repair kinetics. Radiobiological parameters are normalized to correspond to three accepted clinical risk factors based upon T-stage, PSA, and Gleason score to compare models with clinical series. Tumor control probabilities (TCP) for LDR and HDR brachytherapy (as monotherapy or combined with external beam) are compared with clinical bNED survival rates. Predictions are made for dose escalation with HDR brachytherapy regimens. Model predictions for dose escalation with external beam agree with clinical data and validate the models and their underlying assumptions. Both LDR and HDR brachytherapy achieve superior tumor control when compared with external beam at conventional doses (LDR brachytherapy as boost achieves superior tumor control than when used as monotherapy. Stage for stage, both LDR and current HDR regimens achieve similar tumor control rates, in agreement with current clinical data. HDR monotherapy with large-dose fraction sizes might achieve superior tumor control compared with LDR, especially if prostate cancer possesses a high sensitivity to dose fractionation (i.e., if the alpha/beta ratio is low). Radiobiological models support the current clinical evidence for equivalent outcomes in localized

  11. Evaluation of a HDR image sensor with logarithmic response for mobile video-based applications

    Science.gov (United States)

    Tektonidis, Marco; Pietrzak, Mateusz; Monnin, David

    2017-10-01

    The performance of mobile video-based applications using conventional LDR (Low Dynamic Range) image sensors highly depends on the illumination conditions. As an alternative, HDR (High Dynamic Range) image sensors with logarithmic response are capable to acquire illumination-invariant HDR images in a single shot. We have implemented a complete image processing framework for a HDR sensor, including preprocessing methods (nonuniformity correction (NUC), cross-talk correction (CTC), and demosaicing) as well as tone mapping (TM). We have evaluated the HDR sensor for video-based applications w.r.t. the display of images and w.r.t. image analysis techniques. Regarding the display we have investigated the image intensity statistics over time, and regarding image analysis we assessed the number of feature correspondences between consecutive frames of temporal image sequences. For the evaluation we used HDR image data recorded from a vehicle on outdoor or combined outdoor/indoor itineraries, and we performed a comparison with corresponding conventional LDR image data.

  12. Characteristics of hearing loss in HDR (hypoparathyroidism, sensorineural deafness, renal dysplasia) syndrome

    NARCIS (Netherlands)

    van Looij, Marjolein A. J.; Meijers-Heijboer, Hanne; Beetz, Rolf; Thakker, Rajesh V.; Christie, Paul T.; Feenstra, Lou W.; van Zanten, Bert G. A.

    2006-01-01

    Haploinsufficiency of the zinc finger transcription factor GATA3 causes the triad of hypoparathyroidism, deafness and renal dysplasia, known by its acronym HDR syndrome. The purpose of the current study was to describe in detail the auditory phenotype in human HDR patients and compare these to

  13. HDR imaging and color constancy: two sides of the same coin?

    Science.gov (United States)

    McCann, John J.

    2011-01-01

    At first, we think that High Dynamic Range (HDR) imaging is a technique for improved recordings of scene radiances. Many of us think that human color constancy is a variation of a camera's automatic white balance algorithm. However, on closer inspection, glare limits the range of light we can detect in cameras and on retinas. All scene regions below middle gray are influenced, more or less, by the glare from the bright scene segments. Instead of accurate radiance reproduction, HDR imaging works well because it preserves the details in the scene's spatial contrast. Similarly, on closer inspection, human color constancy depends on spatial comparisons that synthesize appearances from all the scene segments. Can spatial image processing play similar principle roles in both HDR imaging and color constancy?

  14. Needle displacement during HDR brachytherapy in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Damore, Steven J.; Syed, A.M. Nisar; Puthawala, Ajmel A.; Sharma, Anil

    2000-01-01

    Purpose: We used clinical patient data to examine implant displacement between high dose rate (HDR) brachytherapy fractions for prostate cancer to determine its impact on treatment delivery. Materials and Methods: We analyzed the verification films taken prior to each fraction for 96 consecutive patients treated with HDR brachytherapy boosts as part of their radiation therapy for definitive treatment of organ-confined prostate cancer at our institution. Patients were treated with 18-24 Gy in 4 fractions of HDR delivered in 40 hours followed by 36-39.6 Gy external beam radiation to the prostate. We determined the mean and maximum displacement distances of marker seeds placed in the prostate and of the implanted needles between HDR fractions. Results: Mean and maximum displacement distances between fractions were documented up to 7.6 mm and 28.5 mm, respectively, for the implant needles and 3.6 mm and 11.4 mm, respectively, for the gold marker seeds. All displacement of implant needles occurred in the caudal direction. At least 1 cm caudal displacement of needles occurred prior to 15.5% all fractions. Manual adjustment of needles was required prior to 15% of fractions, and adjustment of the CLP only was required in 24%. Most of the displacement for both the marker seeds and needles occurred between the first and second fractions. Conclusions: There is significant caudal displacement of interstitial implant needles between HDR fractions in our prostate cancer patients. Obtaining verification films and making adjustments in the treatment volume prior to each fraction is necessary to avoid significant inaccuracies in treatment delivery

  15. Quality assurance of HDR prostate plans: Program implementation at a community hospital

    International Nuclear Information System (INIS)

    Rush, Jennifer B.; Thomas, Michael D.

    2005-01-01

    Adenocarcinoma of the prostate is currently the most commonly diagnosed cancer in men in the United States, and the second leading cause of cancer mortality. The utilization of radiation therapy is regarded as the definitive local therapy of choice for intermediate- and high-risk disease, in which there is increased risk for extracapsular extension, seminal vesicle invasion, or regional node involvement. High-dose-rate (HDR) brachytherapy is a logical treatment modality to deliver the boost dose to an external beam radiation therapy (EBRT) treatment to increase local control rates. From a treatment perspective, the utilization of a complicated treatment delivery system, the compressed time frame in which the procedure is performed, and the small number of large dose fractions make the implementation of a comprehensive quality assurance (QA) program imperative. One aspect of this program is the QA of the HDR treatment plan. Review of regulatory and medical physics professional publications shows that substantial general guidance is available. We provide some insight to the implementation of an HDR prostate plan program at a community hospital. One aspect addressed is the utilization of the low-dose-rate (LDR) planning system and the use of existing ultrasound image sets to familiarize the radiation therapy team with respect to acceptable HDR implant geometries. Additionally, the use of the LDR treatment planning system provided a means to prospectively determine the relationship between the treated isodose volume and the product of activity and time for the department's planning protocol prior to the first HDR implant. For the first 12 HDR prostate implants, the root-mean-square (RMS) deviation was 3.05% between the predicted product of activity and time vs. the actual plan values. Retrospective re-evaluation of the actual implant data reduced the RMS deviation to 2.36%

  16. Quality assurance of HDR prostate plans: program implementation at a community hospital.

    Science.gov (United States)

    Rush, Jennifer B; Thomas, Michael D

    2005-01-01

    Adenocarcinoma of the prostate is currently the most commonly diagnosed cancer in men in the United States, and the second leading cause of cancer mortality. The utilization of radiation therapy is regarded as the definitive local therapy of choice for intermediate- and high-risk disease, in which there is increased risk for extracapsular extension, seminal vesicle invasion, or regional node involvement. High-dose-rate (HDR) brachytherapy is a logical treatment modality to deliver the boost dose to an external beam radiation therapy (EBRT) treatment to increase local control rates. From a treatment perspective, the utilization of a complicated treatment delivery system, the compressed time frame in which the procedure is performed, and the small number of large dose fractions make the implementation of a comprehensive quality assurance (QA) program imperative. One aspect of this program is the QA of the HDR treatment plan. Review of regulatory and medical physics professional publications shows that substantial general guidance is available. We provide some insight to the implementation of an HDR prostate plan program at a community hospital. One aspect addressed is the utilization of the low-dose-rate (LDR) planning system and the use of existing ultrasound image sets to familiarize the radiation therapy team with respect to acceptable HDR implant geometries. Additionally, the use of the LDR treatment planning system provided a means to prospectively determine the relationship between the treated isodose volume and the product of activity and time for the department's planning protocol prior to the first HDR implant. For the first 12 HDR prostate implants, the root-mean-square (RMS) deviation was 3.05% between the predicted product of activity and time vs. the actual plan values. Retrospective re-evaluation of the actual implant data reduced the RMS deviation to 2.36%.

  17. The use of nomograms in LDR-HDR prostate brachytherapy.

    Science.gov (United States)

    Pujades, Ma Carmen; Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

    2011-09-01

    The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification.

  18. The use of nomograms in LDR-HDR prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Ma Carmen Pujades

    2011-09-01

    Full Text Available Purpose: The common use of nomograms in Low Dose Rate (LDR permanent prostate brachytherapy (BT allowsto estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for eachclinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adaptedto High Dose Rate (HDR. This work sets nomograms for LDR and HDR prostate-BT implants, which are applied tothree different institutions that use different implant techniques. Material and methods: Patients treated throughout 2010 till April 2011 were considered for this study. This examplewas chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficientnumber of cases for both BT modalities, prescription dose and different work methodology (depending on theinstitution were taken into account. The specific nomograms were built using the correlation between the prostatevo lume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, numberof implanted seeds in LDR or total radiation time in HDR. Results: For each institution and BT modality, nomograms normalized to the prescribed dose were obtained andfitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting.It should be noted that for each institution these linear function parameters are different, indicating that each centreshould construct its own nomograms. Conclusions: Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific foreach institution. Nevertheless, their use should be complementary to the necessary independent verification.

  19. The relative efficacy of HDR and LDR interstitial brachytherapy in squamous cell carcinoma of vagina

    International Nuclear Information System (INIS)

    Demanes, D. J.; Hsu, I-C.; Lin, S.; Ewing, T.; Rodriguez, R.

    1996-01-01

    Introduction: Beginning in 1982 we performed low dose rate (LDR) interstitial template brachytherapy (ISTB) for carcinoma of the vagina. High dose rate (HDR) remote afterloading has been used exclusively since 1991. We compare the results LDR and HDR brachytherapy. Material and Methods: Between 1982 and 1994, 30 patients with primary squamous cell carcinoma of vagina received external beam radiotherapy (EBRT) and brachytherapy. The AJCC stage distribution was 3 stage I, 25 stage II, and 2 stage III. The average central pelvic EBRT dose was 35 Gy. Pelvic side wall EBRT doses ranged from 45 to 50.4 Gy. Nineteen patients had LDR treatment; 3 intracavitary brachytherapy (ICB) and 16 ISTB. Eleven patients had HDR treatment; 2 ICB and 9 ISB. The average dose delivered by LDR was 41.2 Gy usually in 2 fractions, and by HDR 32.5 Gy in 6 fractions of 500-550 cGy. Local failures were confirmed pathologically. The absolute survival (AS) and relapse-free survival (RFS) were calculated using Kaplan-Meier method and compared with logrank statistics. Results: The mean follow-up was 77 months for LDR and 23 months for HDR. Local and regional control was achieved in 90% (27/30) of the patients. Three year AS was 84% and RFS was 87%. There was no significant difference between LDR and HDR in AS, RFS or local-regional control, (log rank p=0.85, p=0.12 and p=0.35 respectively). The single HDR local failure presented in a patient with extensive stage II disease who declined ISTB. There were fewer complications following HDR. The 1 case of extensive vaginal necrosis and the 3 cases of rectovaginal fistula that required surgery occurred only with LDR brachytherapy. Discussion: Excellent local and regional control of carcinoma of the vagina can be achieved by administering limited doses of external radiation and brachytherapy. Interstitial template implants are the best means of encompassing paravaginal disease while sparing the adjacent uninvolved normal tissues from high doses of

  20. Comparison of radiation shielding requirements for HDR brachytherapy using 169Yb and 192Ir sources

    International Nuclear Information System (INIS)

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Georgiou, E.; Hourdakis, C. J.; Baltas, D.

    2006-01-01

    169 Yb has received a renewed focus lately as an alternative to 192 Ir sources for high dose rate (HDR) brachytherapy. Following the results of a recent work by our group which proved 169 Yb to be a good candidate for HDR prostate brachytherapy, this work seeks to quantify the radiation shielding requirements for 169 Yb HDR brachytherapy applications in comparison to the corresponding requirements for the current 192 Ir HDR brachytherapy standard. Monte Carlo simulation (MC) is used to obtain 169 Yb and 192 Ir broad beam transmission data through lead and concrete. Results are fitted to an analytical equation which can be used to readily calculate the barrier thickness required to achieve a given dose rate reduction. Shielding requirements for a HDR brachytherapy treatment room facility are presented as a function of distance, occupancy, dose limit, and facility workload, using analytical calculations for both 169 Yb and 192 Ir HDR sources. The barrier thickness required for 169 Yb is lower than that for 192 Ir by a factor of 4-5 for lead and 1.5-2 for concrete. Regarding 169 Yb HDR brachytherapy applications, the lead shielding requirements do not exceed 15 mm, even in highly conservative case scenarios. This allows for the construction of a lead door in most cases, thus avoiding the construction of a space consuming, specially designed maze. The effects of source structure, attenuation by the patient, and scatter conditions within an actual treatment room on the above-noted findings are also discussed using corresponding MC simulation results

  1. SU-D-19A-07: Dosimetric Comparison of HDR Plesiotherapy and Electron Beam Therapy for Superficial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A; Jacob, D; Andreou, K; Raben, A; Chen, H; Koprowski, C; Mourtada, F [Christiana Care Hospital, Newark, DE (United States)

    2014-06-01

    Purpose: Large superficial (skin, soft tissue sarcoma) lesions located on curved areas are hard to treat with electrons. The Freiburg Flap (Nucletron, Netherlands) is a flexible mesh style surface which can be easily shaped to fit curved surfaces for reproducible HDR fraction delivery. To understand the fundamental dosimetric differences, a dosimetric comparison was made between HDR plesiotherapy (Freiburg applicator for lesions over 4cm) and external electron beam radiotherapy over cases with varying target curvature (both stylized and clinical cases). Methods: Four stylized cases with variable complexity were created using artificial DICOM axial CT slices and RT structures (a square and three curved structures on a 4.5cm radius cylinder). They were planned using Oncentra v4.3 and exported to Pinnacle v9.6 for electrons planning. The HDR source dwell positions were optimized for the best coverage of the targets using graphical optimization. Electron treatment plans were created in Pinnacle using the same CT and RT structures of three HDR cases with surface lesions previously treated with the Freiburg flap. The En face electron plans used 6-12 MeV electrons and 0.5–1 cm bolus was added to increase surface dose. The electron plans were prescribed to an isodose line to conform to the target. Results: For all lesions, the average target dose coverage was similar (D90ave of 100% for HDR vs 101% for electrons). For lesions with high curvature, the HDR coverage was better (D90 102% vs D90 97% for electron). For all cases, adjacent structures high dose region was lower for HDR than electrons (D1cc 100% for HDR vs D1cc 111% for electrons). Conclusion: HDR plesiotherapy offers excellent target conformity for superficial targets similar to electrons. However, for lesions with complex curved surfaces, HDR has the advantage to achieve better dose distributions using graphical optimization to spare adjacent normal tissue while maximizing target coverage.

  2. Vibrational experiments at the HDR [Heissdampfreaktor] German/US cooperation

    International Nuclear Information System (INIS)

    Kot, C.A.; Malcher, L.; Costello, J.F.

    1987-04-01

    As part of an overall effort on the validation of seismic calculational methods, the US NRC/RES is collaborating with the Kernforschungszentrum Karlsruhe, FRG, in the vibrational/earthquake experiments conducted at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG. In the most recent experiments (SHAG), high level excitations were produced in the HDR by means of an eccentric-mass coastdown shaker capable of developing 1000 tons of force. The purpose of the experiments was to investigate full-scale structural response, soil-structure interaction, and piping and equipment response. Data obtained in the tests serve to evaluate analysis methods. In the SHAG experiments, loadings of the HDR soil-structure system approached incipient failure levels as evidenced by high peak accelerations and displacements, local damage, nonlinear behavior, soil subsidence, and wall strains which exceeded estimated limit values. Also, the performance of different pipe hanger configurations for the VKL piping system was compared in these tests under high excitation levels. The support configurations ranged from very rigid systems (strut/snubbers) to very flexible configurations (spring and constant force supports). Pretest and post-test analyses for the building/soil and piping response were performed and are being validated with the test data

  3. Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

    Science.gov (United States)

    Heredia, Athena Yvonne

    Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

  4. Transition from LDR to HDR brachytherapy for cervical cancer: Evaluation of tumor control, survival, and toxicity.

    Science.gov (United States)

    Romano, K D; Pugh, K J; Trifiletti, D M; Libby, B; Showalter, T N

    In 2012, our institution transitioned from low-dose-rate (LDR) brachytherapy to high dose-rate (HDR) brachytherapy. We report clinical outcomes after brachytherapy for cervical cancer at our institution over a continuous 10-year period. From 2004 to 2014, 258 women (184 LDR and 74 HDR) were treated with tandem and ovoid brachytherapy in the multidisciplinary management of International Federation of Gynecology and Obstetrics Stages IA-IVB cervical cancer. Clinical and treatment-related prognostic factors including age, stage, smoking status, relevant doses, and toxicity data were recorded. Median followup for the LDR and HDR groups was 46 months and 12 months, respectively. The majority of patients (92%) received external beam radiotherapy as well as concurrent chemotherapy (83%) before the start of brachytherapy. For all stages, the 1-year local control and overall survival (OS) rates were comparable between the LDR and HDR groups (87% vs. 81%, p = 0.12; and 75% vs. 85%, p = 0.16), respectively. Factors associated with OS on multivariate analysis include age, stage, and nodal involvement. On multivariate analysis, severe toxicity (acute or chronic) was higher with HDR than LDR (24% vs. 10%, p = 0.04). Additional prognostic factors associated with increased severe toxicity include former/current smokers and total dose to lymph nodes. This comparative retrospective analysis of a large cohort of women treated with brachytherapy demonstrates no significant difference in OS or local control between the LDR and HDR. Acute and chronic toxicity increased shortly after the implementation of HDR, highlighting the importance of continued refinement of HDR methods, including integrating advanced imaging. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  5. Rendering of HDR content on LDR displays: an objective approach

    Science.gov (United States)

    Krasula, Lukáš; Narwaria, Manish; Fliegel, Karel; Le Callet, Patrick

    2015-09-01

    Dynamic range compression (or tone mapping) of HDR content is an essential step towards rendering it on traditional LDR displays in a meaningful way. This is however non-trivial and one of the reasons is that tone mapping operators (TMOs) usually need content-specific parameters to achieve the said goal. While subjective TMO parameter adjustment is the most accurate, it may not be easily deployable in many practical applications. Its subjective nature can also influence the comparison of different operators. Thus, there is a need for objective TMO parameter selection to automate the rendering process. To that end, we investigate into a new objective method for TMO parameters optimization. Our method is based on quantification of contrast reversal and naturalness. As an important advantage, it does not require any prior knowledge about the input HDR image and works independently on the used TMO. Experimental results using a variety of HDR images and several popular TMOs demonstrate the value of our method in comparison to default TMO parameter settings.

  6. Quality assurance of HDR 192Ir sources using a Fricke dosimeter.

    Science.gov (United States)

    Austerlitz, C; Mota, H; Almeida, C E; Allison, R; Sibata, C

    2007-04-01

    A prototype of a Fricke dosimetry system consisting of a 15 x 15 x 15 cm3 water phantom made of Plexiglas and a 11.3-ml Pyrex balloon fitted with a 0.2 cm thick Pyrex sleeve in its center was created to assess source strength and treatment planning algorithms for use in high dose rate (HDR) 192Ir afterloading units. In routine operation, the radioactive source is positioned at the end of a sleeve, which coincides with the center of the spherical balloon that is filled with Fricke solution, so that the solution is nearly isotropically irradiated. The Fricke system was calibrated in terms of source strength against a reference well-type ionization chamber, and in terms of radial dose by means of an existing algorithm from the HDR's treatment planning system. Because the system is based on the Fricke dosimeter itself, for a given type and model of 192Ir source, the system needs initial calibration but no recalibration. The results from measurements made over a 10 month period, including source decay and source substitutions, have shown the feasibility of using such a system for quality control (QC) of HDR afterloading equipment, including both the source activity and treatment planning parameters. The benefit of a large scale production and the use of this device for clinical HDR QC audits via mail are also discussed.

  7. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaofeng, E-mail: xyang43@emory.edu; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Curran, Walter J.; Liu, Tian [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322 (United States); Mao, Hui [Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia 30322 (United States)

    2014-11-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

  8. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    Science.gov (United States)

    Yang, Xiaofeng; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Mao, Hui; Curran, Walter J.; Liu, Tian

    2014-01-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

  9. Intraoperative HDR implant boost for breast cancer (preliminary results)

    International Nuclear Information System (INIS)

    Rodriguez, I.; Torre, M. de la; Gonzalez, E.; Bourel, V.

    1996-01-01

    Introduction: In spite of the fact that it is been discussed whether or not a boost is necessary for all conservative treated breast cancer patients, it is a generalized radiotherapy practice. Since september 1993 we developed a breast conservative protocol for early stage breast cancer (T1-T2) with intraoperative HDR implant boost. Side effects, cosmetic results and recurrence rates are reviewed. Method and Material: From September 1993 we treated 55 patients with intraoperative HDR implant boost to the lumpectomy site for clinical T1 or T2 invasive breast cancer, followed by external megavoltage radiotherapy to the entire breast. We used the Nucletron microselectron HDR remote afterloading system with flexible implant tubes. The geometric distribution of the tubes was performed according to the 'Paris' configuration. Each implant was evaluated by calculating the dose-volume natural histograms. The HDR fractionation schedule consists of three fractions of 4.5Gy each given at least 48 hs apart, and starting between 48-72hs from surgical procedure. The external radiotherapy to the entire breast started one week after the completion of brachytherapy, using conventional fractionation of 5 fractions per week, 1,8Gy per fraction up to 45-50Gy. Results: So far there is not any local recurrence, but medium follow up is only 18 months. We did not observe any acute damage and the cosmetic outcome was 60% excellent, 30% good and 10% acceptable. Two patients developed localized fibrosis, in both the implant involved the submamary fold. Conclusion: The intraoperative implant is the most accurate way to localize the lumpectomy site, to define the target volume, decrease the total treatment time and avoid a second anesthetic procedure without delaying the inpatient time or the initial wound healing process

  10. Experience of the first application of HDR brachytherapy in nasopharynx

    International Nuclear Information System (INIS)

    Vega Hernandez, Manuel I.; Alfonso Laguardia, Rodolfo; Silvestre Patallo, Ileana; Roca Muchuli, Carlos; Garcia Heredia, Gilda

    2006-01-01

    A research was made by applying boost on the area of the nasopharynx relapse with high dose rate (HDR) in a diagnosis of nasopharynx carcinoma previously treated with telecobalt therapy, at a dose of 70 Gy. There was persistence of the injury. Three sessions were planned, with consecutive fractions of 6.5 Gy in 15 days, with optimization, using a personal mould of autopolymerizable acrylic. The successful possibility to apply the high rate modern brachytherapy was reaffirmed, as a treatment complementary to teletherapy in case of persistence or relapse. A Micro Selectron HDR equipment was used

  11. Estimate of dose in interventional radiology: a study of cases

    International Nuclear Information System (INIS)

    Pinto, N.; Braz, D.; Lopes, R.; Vallim, M.; Padilha, L.; Azevedo, F.; Barroso, R.

    2006-01-01

    Values of absorbed dose taken by patients and professionals involved in interventional radiology can be significant mainly for the reason of these proceedings taking long time of fluoroscopy There are many methods to estimate and reduce doses of radiation in the interventional radiology, particularly because the fluoroscopy is responsible for the high dose contribution in the patient and in the professional. The aim of this work is the thermoluminescent dosimetry to estimate the dose values of the extremities of the professionals involved in the interventional radiology and the product dose-area was investigated using a Diamentor. This evaluation is particularly useful for proceedings that interest multiple parts of the organism. In this study were used thermoluminescent dosimeters (LiF:Mg, Ti - Harshaw) to estimate the dose values of the extremities of the professionals and to calibrate them. They were irradiated with X rays at 50 mGy, in Kerma in air and read in the reader Harshaw-5500. The product dose-area (D.A.P.) were obtained through the Diamentor (M2-P.T.W.) calibrated in Cgy.cm 2 fixed in the exit of the X-rays tube. The patients of these study were divided in three groups: individuals submitted to proceedings of embolization, individuals submitted to cerebral and renal arteriography and individuals submitted to proceedings of Transjungular Inthahepatic Porta Systemic Stent Shunt (TIPS). The texts were always carried out by the same group: radiologist doctor), an auxiliary doctor and a nursing auxiliary. The section of interventional radiology has an Angiostar Plus Siemens equipment type arc C, in which there is trifocal Megalix X-ray tube and a intensifier of image from Sirecon 40-4 HDR/33 HDR. In this work the dose estimated values were 137.25 mSv/year for the doctors, 40.27 mSv/year for the nursing and 51.95 mSv/year for the auxiliary doctor and they are below the rule, but in this study it was not taken in consideration the emergency texts as they were

  12. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

    International Nuclear Information System (INIS)

    Zhen, Xin; Chen, Haibin; Zhou, Linghong; Yan, Hao; Jiang, Steve; Jia, Xun; Gu, Xuejun; Mell, Loren K; Yashar, Catheryn M; Cervino, Laura

    2015-01-01

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses. (paper)

  13. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

    Science.gov (United States)

    Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K.; Yashar, Catheryn M.; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

    2015-04-01

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

  14. A Survey on the Acceptance and the Use of HDR Photography Among Croatian Photographers

    Directory of Open Access Journals (Sweden)

    Maja Strgar Kurecic

    2013-04-01

    Full Text Available The emerging field of high dynamic range (HDR imaging is directly linked to diverse existing disciplines such as radiometry, photometry, colorimetry and colour appearance - each dealing with specific aspects of light and its perception by humans. Although the idea is not new, it has not been widely used until just a few years ago when digital cameras gained popularity and the computers processing power increased significantly. Now this photographic technique is widely spread and used, but even more often – misused. A research was conducted by means of a questionnaire in order to get some actual information about how Croatian photographers see the HDR photography and how they employ it. The results of the survey proved that indeed a great interest exists in the technique, but that many photographers are scared away from the HDR photography because of the misconception that the artificial look is an unavoidable side effect of the HDR processing. The fact is, however, that the final HDR image is a result of the tone mapping process and post-corrections and adjustments, entirely dependent on the photographer’s intent and vision, as well as his understanding of various adjustments available. The results of the questionnaire have also pointed out to other widely spread misconceptions which are discussed in this paper.

  15. Highly efficient CRISPR/HDR-mediated knock-in for mouse embryonic stem cells and zygotes.

    Science.gov (United States)

    Wang, Bangmei; Li, Kunyu; Wang, Amy; Reiser, Michelle; Saunders, Thom; Lockey, Richard F; Wang, Jia-Wang

    2015-10-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) gene editing technique, based on the non-homologous end-joining (NHEJ) repair pathway, has been used to generate gene knock-outs with variable sizes of small insertion/deletions with high efficiency. More precise genome editing, either the insertion or deletion of a desired fragment, can be done by combining the homology-directed-repair (HDR) pathway with CRISPR cleavage. However, HDR-mediated gene knock-in experiments are typically inefficient, and there have been no reports of successful gene knock-in with DNA fragments larger than 4 kb. Here, we describe the targeted insertion of large DNA fragments (7.4 and 5.8 kb) into the genomes of mouse embryonic stem (ES) cells and zygotes, respectively, using the CRISPR/HDR technique without NHEJ inhibitors. Our data show that CRISPR/HDR without NHEJ inhibitors can result in highly efficient gene knock-in, equivalent to CRISPR/HDR with NHEJ inhibitors. Although NHEJ is the dominant repair pathway associated with CRISPR-mediated double-strand breaks (DSBs), and biallelic gene knock-ins are common, NHEJ and biallelic gene knock-ins were not detected. Our results demonstrate that efficient targeted insertion of large DNA fragments without NHEJ inhibitors is possible, a result that should stimulate interest in understanding the mechanisms of high efficiency CRISPR targeting in general.

  16. Genitourinary Toxicity After High-Dose-Rate (HDR) Brachytherapy Combined With Hypofractionated External Beam Radiotherapy for Localized Prostate Cancer: An Analysis to Determine the Correlation Between Dose-Volume Histogram Parameters in HDR Brachytherapy and Severity of Toxicity

    International Nuclear Information System (INIS)

    Ishiyama, Hiromichi; Kitano, Masashi; Satoh, Takefumi; Kotani, Shouko; Uemae, Mineko; Matsumoto, Kazumasa; Okusa, Hiroshi; Tabata, Ken-ichi; Baba, Shiro; Hayakawa, Kazushige

    2009-01-01

    Purpose: To evaluate the severity of genitourinary (GU) toxicity in high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiotherapy (EBRT) for prostate cancer and to explore factors that might affect the severity of GU toxicity. Methods and Materials: A total of 100 Japanese men with prostate cancer underwent 192 Ir HDR brachytherapy combined with hypofractionated EBRT. Mean (SD) dose to 90% of the planning target volume was 6.3 (0.7) Gy per fraction of HDR. After 5 fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administrated. The urethral volume receiving 1-15 Gy per fraction in HDR brachytherapy (V1-V15) and the dose to at least 5-100% of urethral volume in HDR brachytherapy (D5-D100) were compared between patients with Grade 3 toxicity and those with Grade 0-2 toxicity. Prostate volume, patient age, and International Prostate Symptom Score were also compared between the two groups. Results: Of the 100 patients, 6 displayed Grade 3 acute GU toxicity, and 12 displayed Grade 3 late GU toxicity. Regarding acute GU toxicity, values of V1, V2, V3, and V4 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Regarding late GU toxicity, values of D70, D80, V12, and V13 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Conclusions: The severity of GU toxicity in HDR brachytherapy combined with hypofractionated EBRT for prostate cancer was relatively high. The volume of prostatic urethra was associated with grade of acute GU toxicity, and urethral dose was associated with grade of late GU toxicity.

  17. SU-F-T-55: Reproducibility of Interstitial HDR Brachytherapy Plans

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Ellis, R; Traughber, B; Podder, T [University Hospitals Case Medical Center, Cleveland, OH (United States)

    2016-06-15

    Purpose: Treating gynecological cancers with interstitial high-dose-rate (HDR) brachytherapy requires precise reconstruction of catheter positions to obtain accurate dosimetric plans. In this study, we investigated the degree of reproducibility of dosimetric plans for Syed HDR brachytherapy. Methods: We randomly selected five patients having cervix-vaginal cancer who were recently treated in our clinic with interstitial HDR brachytherapy with a prescription dose of 25–30 Gy in five fractions. Interstitial needles/catheters were placed under fluoroscopic guidance and intra-operative 3T MRI scan was performed to confirm the desired catheter placement for adequate target volume coverage. A CT scan was performed and fused with the MRI for delineating high-risk CTV (HR-CTV), intermediate-risk CTV (IR-CTV) and OARs. HDR treatment plans were generated using Oncentra planning software. A single plan was used for all five fractions of treatment for each patient. For this study, we took the original clinical plan and removed all the reconstructed catheters from the plan keeping the original contours unchanged. Then, we manually reconstructed all the catheters and entered the same dwell time from the first original clinical plan. The dosimetric parameters studied were: D90 for HR-CTV and IR-CV, and D2cc for bladder, rectum, sigmoid and bowel. Results: The mean of absolute differences in dosimetric coverage (D90) were (range): 1.3% (1.0–2.0%) and 2.0% (0.9–3.6%) for HR-CTV and IR-CTV, respectively. In case of OARs, the mean of absolute variations in D2cc were (range): 4.7% (0.7–8.9%) for bladder, 1.60% (0.3–3.2%) for rectum, 1.6% (0–3.9%) for sigmoid, and 1.8% (0–5.1%) for bowel. Conclusion: Overall, the reproducibility of interstitial HDR plans was within clinically acceptable limit. Observed maximum variation in D2cc for bladder. If number of catchers and dwell points were relatively low or any one catheter was heavily loaded, then reproducibility of the plan

  18. Perioperative high dose rate (HDR brachytherapy in unresectable locally advanced pancreatic tumors

    Directory of Open Access Journals (Sweden)

    Brygida Białas

    2011-07-01

    Full Text Available Purpose: The aim of the study was to present an original technique of catheter implantation for perioperative HDR-Ir192 brachytherapy in patients after palliative operations of unresectable locally advanced pancreatic tumors and to estimate the influence of perioperative HDR-Ir192 brachytherapy on pain relief in terminal pancreatic cancer patients. Material and methods: Eight patients with pancreatic tumors located in the head of pancreas underwent palliative operations with the use of HDR-Ir192 brachytherapy. All patients qualified for surgery reported pain of high intensity and had received narcotic painkillers prior to operation. During the last phase of the surgery, the Nucletron® catheters were implanted in patients to prepare them for later perioperative brachytherapy. Since the 6th day after surgery HDR brachytherapy was performed. Before each brachytherapy fraction the location of implants were checked using fluoroscopy. A fractional dose was 5 Gy and a total dose was 20 Gy in the area of radiation. A comparative study of two groups of patients (with and without brachytherapy with stage III pancreatic cancer according to the TNM scale was taken in consideration. Results and Conclusions: The authors claim that the modification of catheter implantation using specially designed cannula, facilitates the process of inserting the catheter into the tumor, shortens the time needed for the procedure, and reduces the risk of complications. Mean survival time was 5.7 months. In the group of performed brachytherapy, the mean survival time was 6.7 months, while in the group of no brachytherapy performed – 4.4 months. In the group of brachytherapy, only one patient increased the dose of painkillers in the last month of his life. Remaining patients took constant doses of medicines. Perioperative HDR-Ir192 brachytherapy could be considered as a practical application of adjuvant therapy for pain relief in patients with an advanced pancreatic cancer.

  19. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    International Nuclear Information System (INIS)

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David; Alvarez, Paola; Lawyer, Ann

    2013-01-01

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm 3 prototype phantom that had two slots capable of holding Al 2 O 3 :C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all 192 Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian 192 Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k L = (−9.43 × 10 −5 × dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using 60 Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian 192 Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a

  20. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Alvarez, Paola; Lawyer, Ann [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-11-15

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm{sup 3} prototype phantom that had two slots capable of holding Al{sub 2}O{sub 3}:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all {sup 192}Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian {sup 192}Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k{sub L}= (−9.43 × 10{sup −5}× dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using {sup 60}Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian {sup 192}Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance

  1. High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

    Science.gov (United States)

    Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

    2015-04-01

    Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

  2. NOTE: Monte Carlo evaluation of kerma in an HDR brachytherapy bunker

    Science.gov (United States)

    Pérez-Calatayud, J.; Granero, D.; Ballester, F.; Casal, E.; Crispin, V.; Puchades, V.; León, A.; Verdú, G.

    2004-12-01

    In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, maintaining a similar value along the length of the maze. The comparison of results from the aforementioned values with the Monte Carlo ones shows that results obtained using the albedo coefficient from the ICRP document more closely match those given by the Monte Carlo method, although the maximum value given by MC calculations is 30% greater.

  3. Dosimetric comparison between the microSelectron HDR 192Ir v2 source and the BEBIG 60Co source for HDR brachytherapy using the EGSnrc Monte Carlo transport code

    International Nuclear Information System (INIS)

    Anwarul Islam, M.; Akramuzzaman, M.M.; Zakaria, G.A.

    2012-01-01

    Manufacturing of miniaturized high activity 192 Ir sources have been made a market preference in modern brachytherapy. The smaller dimensions of the sources are flexible for smaller diameter of the applicators and it is also suitable for interstitial implants. Presently, miniaturized 60 Co HDR sources have been made available with identical dimensions to those of 192 Ir sources. 60 Co sources have an advantage of longer half life while comparing with 192 Ir source. High dose rate brachytherapy sources with longer half life are logically pragmatic solution for developing country in economic point of view. This study is aimed to compare the TG-43U1 dosimetric parameters for new BEBIG 60 Co HDR and new microSelectron 192 Ir HDR sources. Dosimetric parameters are calculated using EGSnrc-based Monte Carlo simulation code accordance with the AAPM TG-43 formalism for microSelectron HDR 192 Ir v2 and new BEBIG 60 Co HDR sources. Air-kerma strength per unit source activity, calculated in dry air are 9.698x10 -8 ± 0.55% U Bq -1 and 3.039x10 -7 ± 0.41% U Bq -1 for the above mentioned two sources, respectively. The calculated dose rate constants per unit air-kerma strength in water medium are 1.116±0.12% cGy h -1 U -1 and 1.097±0.12% cGy h -1 U -1 , respectively, for the two sources. The values of radial dose function for distances up to 1 cm and more than 22 cm for BEBIG 60 Co HDR source are higher than that of other source. The anisotropic values are sharply increased to the longitudinal sides of the BEBIG 60 Co source and the rise is comparatively sharper than that of the other source. Tissue dependence of the absorbed dose has been investigated with vacuum phantom for breast, compact bone, blood, lung, thyroid, soft tissue, testis, and muscle. No significant variation is noted at 5 cm of radial distance in this regard while comparing the two sources except for lung tissues. The true dose rates are calculated with considering photon as well as electron transport using

  4. A review of the HDR research programme

    International Nuclear Information System (INIS)

    Talja, H.; Koski, K.; Rintamaa, R.; Keskinen, R.

    1995-10-01

    In the German HDR (Heissdampfreaktor, hot steam reactor) reactor safety programme, experiments and simulating numerical analyses have been undertaken since 1976 to study the integrity and safety of light water reactors under operational and faulted conditions. The last experiments of the programme were conducted in 1991. The post test analyses have been finished by March 1994 and the last final reports were obtained a few months later. The report aims to inform the utilities and the regulatory body of Finland about the contents of the lokset HDR research programme and to consider the applicability of the results to safety analyses of Finnish nuclear power plants. The report centers around the thermal shock and piping component experiments within the last or third phase of the HDR programme. Investigations into severe reactor accidents, fire safety and non-destructive testing, also conducted during the third phase, are not considered. The report presents a review of the following experiment groups: E21 (crack growth under corrosive conditions, loading due to thermal stratification), E22 (leak rate and leak detection experiments of through-cracked piping), E23 (thermal transient and stratification experiments for a pipe nozzle), E31 (vibration of cracked piping due to blow down and closure of isolation valve), E32 (seismically induced vibrations of cracked piping), E33 (condensation phenomena in horizontal piping during emergency cooling). A comprehensive list of reference reports, received by VTT and containing a VTT more detailed description, is given for each experiment group. The review is focused on the loading conditions and their theoretical modelling. A comparison of theoretical and experimental results is presented for each experiment group. The safety margins are finally assessed with special reference to leak-before-break, a well known principle for assuring the integrity of primary circuit piping of nuclear power plants. (orig.) (71 figs., 5 tabs.)

  5. HDR brachytherapy for superficial non-melanoma skin cancers

    International Nuclear Information System (INIS)

    Gauden, Ruth; Pracy, Martin; Avery, Anne-Marie; Hodgetts, Ian; Gauden, Stan

    2013-01-01

    Our initial experience using recommended high dose per fraction skin brachytherapy (BT) treatment schedules, resulted in poor cosmesis. This study aimed to assess in a prospective group of patients the use of Leipzig surface applicators for High Dose Rate (HDR) brachytherapy, for the treatment of small non-melanoma skin cancers (NMSC) using a protracted treatment schedule. Treatment was delivered by HDR brachytherapy with Leipzig applicators. 36Gy, prescribed to between 3 to 4mm, was given in daily 3Gy fractions. Acute skin toxicity was evaluated weekly during irradiation using the Radiation Therapy Oncology Group criteria. Local response, late skin effects and cosmetic results were monitored at periodic intervals after treatment completion. From March 2002, 200 patients with 236 lesions were treated. Median follow-up was 66 months (range 25–121 months). A total of 162 lesions were macroscopic, while in 74 cases, BT was given after resection because of positive microscopic margins. There were 121 lesions that were basal cell carcinomas, and 115 were squamous cell carcinomas. Lesions were located on the head and neck (198), the extremities (26) and trunk (12). Local control was 232/236 (98%). Four patients required further surgery to treat recurrence. Grade 1 acute skin toxicity was detected in 168 treated lesions (71%) and grade 2 in 81 (34%). Cosmesis was good or excellent in 208 cases (88%). Late skin hypopigmentation changes were observed in 13 cases (5.5%). Delivering 36Gy over 2 weeks to superficial NMSC using HDR brachytherapy is well tolerated and provides a high local control rate without significant toxicity.

  6. Time to PSA rise differentiates the PSA bounce after HDR and LDR brachytherapy of prostate cancer.

    Science.gov (United States)

    Burchardt, Wojciech; Skowronek, Janusz

    2018-02-01

    To investigate the differences in prostate-specific antigen (PSA) bounce (PB) after high-dose-rate (HDR-BT) or low-dose-rate (LDR-BT) brachytherapy alone in prostate cancer patients. Ninety-four patients with localized prostate cancer (T1-T2cN0), age ranged 50-81 years, were treated with brachytherapy alone between 2008 and 2010. Patients were diagnosed with adenocarcinoma, Gleason score ≤ 7. The LDR-BT total dose was 144-145 Gy, in HDR-BT - 3 fractions of 10.5 or 15 Gy. The initial PSA level (iPSA) was assessed before treatment, then PSA was rated every 3 months over the first 2 years, and every 6 months during the next 3 years. Median follow-up was 3.0 years. Mean iPSA was 7.8 ng/ml. In 58 cases, PSA decreased gradually without PB or biochemical failure (BF). In 24% of patients, PB was observed. In 23 cases (24%), PB was observed using 0.2 ng/ml definition; in 10 cases (11%), BF was diagnosed using nadir + 2 ng/ml definition. The HDR-BT and LDR-BT techniques were not associated with higher level of PB (26 vs. 22%, p = 0.497). Time to the first PSA rise finished with PB was significantly shorter after HDR-BT then after LDR-BT (median, 10.5 vs. 18.0 months) during follow-up. Predictors for PB were observed only after HDR-BT. Androgen deprivation therapy (ADT) and higher Gleason score decreased the risk of PB (HR = 0.11, p = 0.03; HR = 0.51, p = 0.01). The higher PSA nadir and longer time to PSA nadir increased the risk of PB (HR 3.46, p = 0.02; HR 1.04, p = 0.04). There was no predictors for PB after LDR-BT. HDR-BT and LDR-BT for low and intermediate risk prostate cancer had similar PB rate. The PB occurred earlier after HDR-BT than after LDR-BT. ADT and higher Gleason score decreased, and higher PSA nadir and longer time to PSA nadir increased the risk of PB after HDR-BT.

  7. The Oryza sativa Regulator HDR1 Associates with the Kinase OsK4 to Control Photoperiodic Flowering.

    Directory of Open Access Journals (Sweden)

    Xuehui Sun

    2016-03-01

    Full Text Available Rice is a facultative short-day plant (SDP, and the regulatory pathways for flowering time are conserved, but functionally modified, in Arabidopsis and rice. Heading date 1 (Hd1, an ortholog of Arabidopsis CONSTANS (CO, is a key regulator that suppresses flowering under long-day conditions (LDs, but promotes flowering under short-day conditions (SDs by influencing the expression of the florigen gene Heading date 3a (Hd3a. Another key regulator, Early heading date 1 (Ehd1, is an evolutionarily unique gene with no orthologs in Arabidopsis, which acts as a flowering activator under both SD and LD by promoting the rice florigen genes Hd3a and RICE FLOWERING LOCUST 1 (RFT1. Here, we report the isolation and characterization of the flowering regulator Heading Date Repressor1 (HDR1 in rice. The hdr1 mutant exhibits an early flowering phenotype under natural LD in a paddy field in Beijing, China (39°54'N, 116°23'E, as well as under LD but not SD in a growth chamber, indicating that HDR1 may functionally regulate flowering time via the photoperiod-dependent pathway. HDR1 encodes a nuclear protein that is most active in leaves and floral organs and exhibits a typical diurnal expression pattern. We determined that HDR1 is a novel suppressor of flowering that upregulates Hd1 and downregulates Ehd1, leading to the downregulation of Hd3a and RFT1 under LDs. We have further identified an HDR1-interacting kinase, OsK4, another suppressor of rice flowering under LDs. OsK4 acts similarly to HDR1, suppressing flowering by upregulating Hd1 and downregulating Ehd1 under LDs, and OsK4 can phosphorylate HD1 with HDR1 presents. These results collectively reveal the transcriptional regulators of Hd1 for the day-length-dependent control of flowering time in rice.

  8. Determinación de la distribución de dosis en tratamientos de cáncer de mama con fuentes de 192 Ir HDR / Determination of doses distributions on breast cancer treatments with 192 Ir HDR sources

    OpenAIRE

    Beltrán Gómez, Cristian Camilo

    2010-01-01

    La Braquiterapia de alta tasa de dosis HDR es una moderna técnica de tratamiento que ha venido teniendo un rápido crecimiento en su uso clínico, reemplazando a la braquiterapia de baja tasa de dosis LDR. La braquiterapia HDR se caracteriza por utilizar fuentes radiactivas con tasas de dosis mayores a 12 Gy/h, por tanto con propósitos de protección radiológica debe ser realizada con equipos de carga remota, es común en los tratamientos de braquiterapia HDR depositar altas dosis por fracción, c...

  9. Dosimetry experience of 192IR sources used In HDR brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Daci, Lulzime; Myrku, Rodina Cela

    2013-01-01

    Purpose/Objective: The 192IR Sources are the most commonly used in radiotherapy treatments HDR worldwide. According to international recommendations on quality assurance in HDR brachytherapy, an acceptance test based on the determination of the source strength of any new source shall be carried out before first application to verify the manufacturer’s calibration data. The present paper gives the experimental determination of the source strength for our brachytherapy sources used until now in brachytherapy treatments. Materials/Methods: At Mother Teresa University Hospital we have a cost-effective gynecological brachytherapy unit from Eckert & Ziegler BEBIG named GyneSource® that is a five channel HDR after loader equipped with an 192IR source. The software used is HDR plus™ 2.5 that delivers an optimized treatment plan and makes the process especially fast and we use intracavitary BEBIG applicators. From April 2009 up to December 2012, we have imported nine HDR 192IR Sources. The exchange of the source and acceptance test is done by the physicist of the clinic once the source is imported. The measurements are done with a Well-type ionization chamber HDR1000 Plus and the electrometer used is MAX4000. Only seven sources are compared as we miss the dosimetry data of the first source, and the forth source was not measured and not used because the machine was not working in that time. Results/Conclusions: Eight sources were accepted for clinically use as the measurement were within the tolerance. The source number four with e deviation of -1.92% has been double checked compared with a free in-air measurement with farmer type chamber that gave a deviation to source certificate of 4% that is still inside the tolerance to accept a source for clinical use. The deviations of measured Air Kerma rate to the value of the sources certificates of all our used 192IR sources are less than 2%, which are within the tolerance. The checked value of updated source strength in

  10. Investigation of superstructure damping identification for the HDR containment building

    International Nuclear Information System (INIS)

    Hsieh, B.J.; Kot, C.A.; Srinivasan, M.G.

    1985-01-01

    A method for the estimation of first mode structural damping, developed by other investigators, was applied to shaker test data of the HDR containment building. Due to inadequate precision in the experimental phase measurements no valid results could be obtained. Based on modal analysis it was also noted that for systems such as the HDR building, contributions of higher modes are not negligible as was assumed in the original approach. Therefore, the procedure for the determination of superstructure damping using experimental data was extended to include the effects of higher modes. The extended method does not lead to any higher order nonlinear equations than the first mode approximation and was found to be as simple to apply as the original approach

  11. The high dynamic range pixel array detector (HDR-PAD): Concept and design

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.; Becker, Julian; Tate, Mark W. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: smg26@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

    2016-07-27

    Experiments at storage ring light sources as well as at next-generation light sources increasingly require detectors capable of high dynamic range operation, combining low-noise detection of single photons with large pixel well depth. XFEL sources in particular provide pulse intensities sufficiently high that a purely photon-counting approach is impractical. The High Dynamic Range Pixel Array Detector (HDR-PAD) project aims to provide a dynamic range extending from single-photon sensitivity to 10{sup 6} photons/pixel in a single XFEL pulse while maintaining the ability to tolerate a sustained flux of 10{sup 11} ph/s/pixel at a storage ring source. Achieving these goals involves the development of fast pixel front-end electronics as well as, in the XFEL case, leveraging the delayed charge collection due to plasma effects in the sensor. A first prototype of essential electronic components of the HDR-PAD readout ASIC, exploring different options for the pixel front-end, has been fabricated. Here, the HDR-PAD concept and preliminary design will be described.

  12. MO-C-17A-11: A Segmentation and Point Matching Enhanced Deformable Image Registration Method for Dose Accumulation Between HDR CT Images

    International Nuclear Information System (INIS)

    Zhen, X; Chen, H; Zhou, L; Yan, H; Jiang, S; Jia, X; Gu, X; Mell, L; Yashar, C; Cervino, L

    2014-01-01

    Purpose: To propose and validate a novel and accurate deformable image registration (DIR) scheme to facilitate dose accumulation among treatment fractions of high-dose-rate (HDR) gynecological brachytherapy. Method: We have developed a method to adapt DIR algorithms to gynecologic anatomies with HDR applicators by incorporating a segmentation step and a point-matching step into an existing DIR framework. In the segmentation step, random walks algorithm is used to accurately segment and remove the applicator region (AR) in the HDR CT image. A semi-automatic seed point generation approach is developed to obtain the incremented foreground and background point sets to feed the random walks algorithm. In the subsequent point-matching step, a feature-based thin-plate spline-robust point matching (TPS-RPM) algorithm is employed for AR surface point matching. With the resulting mapping, a DVF characteristic of the deformation between the two AR surfaces is generated by B-spline approximation, which serves as the initial DVF for the following Demons DIR between the two AR-free HDR CT images. Finally, the calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. Results: The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative results as well as the visual inspection of the DIR indicate that our proposed method can suppress the interference of the applicator with the DIR algorithm, and accurately register HDR CT images as well as deform and add interfractional HDR doses. Conclusions: We have developed a novel and robust DIR scheme that can perform registration between HDR gynecological CT images and yield accurate registration results. This new DIR scheme has potential for accurate interfractional HDR dose accumulation. This work is supported in part by the National Natural ScienceFoundation of China (no 30970866 and no

  13. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    Science.gov (United States)

    Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

    2010-08-01

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  14. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    International Nuclear Information System (INIS)

    Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

    2010-01-01

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  15. Lehrerkooperation: theoretische reflexion über voraussetzungen zur erweiterung von kooperativität bei lehrern

    Directory of Open Access Journals (Sweden)

    Rainer Lengert

    2012-01-01

    Full Text Available Viele Bildungseinrichtungen verfolgen den Ausbau der Zusammenarbeit zwischen Lehrern, mit der Absicht, das Arbeitsklima zu pflegen und vor allem zur Verbesserung der Qualität ihres Bildungsangebotes. Allerdings bereiten die kooperativen Initiativen oft Unannehmlichkeiten, es sei denn, die Beteiligten kennen die umfangreichen Hintergründe, die höhere oder mindere Ebenen von Kooperation erleichtern oder behindern können. Diese Lücke wird im vorliegenden Artikel abgehandelt, indem neun Prämissen als Voraussetzung zur Erweiterung der Kooperation zwischen Lehrern dargestellt werden. Im Bewusstsein dieser Prämissen, ist es möglich, empirische Erforschungen künftig zu instrumentalisieren, wie auch Wege zu schaffen, Anforderungen an Lehrer und Schulen gewisser zu verwalten.Abstract Muitas instituições escolares têm aderido à busca de ampliar a cooperação entre seus professores, com a intenção de cuidar do ambiente de trabalho, mas, principalmente, de melhorar a qualidade de ensino oferecida. Porém, as iniciativas cooperativas costumam enfrentar dificuldades, sem que os envolvidos tenham conhecimento das causas amplas que impedem ou facilitam maiores ou menores níveis de cooperação. É dessa lacuna que trata o presente artigo, discutindo nove premissas que subjazem à possibilidade de ampliar a cooperação entre professores. Tendo consciência das premissas, é possível instrumentalizar futuras pesquisas empíricas, como também criar meios de gerir os requisitos que são de responsabilidade dos professores e das instituições escolares.

  16. A comparison of HDR brachytherapy and IMRT techniques for dose escalation in prostate cancer: A radiobiological modeling study

    Energy Technology Data Exchange (ETDEWEB)

    Fatyga, M.; Williamson, J. F.; Dogan, N.; Todor, D.; Siebers, J. V.; George, R.; Barani, I.; Hagan, M. [Department of Radiation Oncology, Virginia Commonwealth University Medical Center, 401 College Street, Richmond, Virginia 23298 (United States)

    2009-09-15

    A course of one to three large fractions of high dose rate (HDR) interstitial brachytherapy is an attractive alternative to intensity modulated radiation therapy (IMRT) for delivering boost doses to the prostate in combination with additional external beam irradiation for intermediate risk disease. The purpose of this work is to quantitatively compare single-fraction HDR boosts to biologically equivalent fractionated IMRT boosts, assuming idealized image guided delivery (igIMRT) and conventional delivery (cIMRT). For nine prostate patients, both seven-field IMRT and HDR boosts were planned. The linear-quadratic model was used to compute biologically equivalent dose prescriptions. The cIMRT plan was evaluated as a static plan and with simulated random and setup errors. The authors conclude that HDR delivery produces a therapeutic ratio which is significantly better than the conventional IMRT and comparable to or better than the igIMRT delivery. For the HDR, the rectal gBEUD analysis is strongly influenced by high dose DVH tails. A saturation BED, beyond which no further injury can occur, must be assumed. Modeling of organ motion uncertainties yields mean outcomes similar to static plan outcomes.

  17. Prediction of HDR quality by combining perceptually transformed display measurements with machine learning

    Science.gov (United States)

    Choudhury, Anustup; Farrell, Suzanne; Atkins, Robin; Daly, Scott

    2017-09-01

    We present an approach to predict overall HDR display quality as a function of key HDR display parameters. We first performed subjective experiments on a high quality HDR display that explored five key HDR display parameters: maximum luminance, minimum luminance, color gamut, bit-depth and local contrast. Subjects rated overall quality for different combinations of these display parameters. We explored two models | a physical model solely based on physically measured display characteristics and a perceptual model that transforms physical parameters using human vision system models. For the perceptual model, we use a family of metrics based on a recently published color volume model (ICT-CP), which consists of the PQ luminance non-linearity (ST2084) and LMS-based opponent color, as well as an estimate of the display point spread function. To predict overall visual quality, we apply linear regression and machine learning techniques such as Multilayer Perceptron, RBF and SVM networks. We use RMSE and Pearson/Spearman correlation coefficients to quantify performance. We found that the perceptual model is better at predicting subjective quality than the physical model and that SVM is better at prediction than linear regression. The significance and contribution of each display parameter was investigated. In addition, we found that combined parameters such as contrast do not improve prediction. Traditional perceptual models were also evaluated and we found that models based on the PQ non-linearity performed better.

  18. A gEUD-based inverse planning technique for HDR prostate brachytherapy: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, D. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78229 (United States); Department of Radiation Oncology, Francis H. Burr Proton Therapy Center, Boston, Massachusetts 02114 (United States); Baltas, D. [Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Nuclear and Particle Physics Section, Physics Department, University of Athens, 15701 Athens (Greece); Karabis, A. [Pi-Medical Ltd., Athens 10676 (Greece); Mavroidis, P. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 and Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, 17176 (Sweden); Zamboglou, N.; Tselis, N. [Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Shi, C. [St. Vincent' s Medical Center, 2800 Main Street, Bridgeport, Connecticut 06606 (United States); Papanikolaou, N. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 (United States)

    2013-04-15

    Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D{sub 10} or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

  19. Vibrational experiments at the HDR [Heissdampfreaktor]: SHAG results and planning for SHAM

    International Nuclear Information System (INIS)

    Kot, C.A.; Malcher, L.; Steinhilber, H.

    1987-01-01

    As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level shaker tests (SHAG) were performed during June and July 1986 using a coast-down shaker capable of generating 1000 tons of force. The purpose of these experiments was to investigate full-scale structural response, soil/structure interaction, and piping and equipment response under strong excitation conditions. While global safety considerations imposed load limitations, the HDR soil/structure system was nevertheless tested to incipient failure. The performance of pipe support systems in as many as seven different multiple support pipe hanger configurations, ranging from flexible to stiff systems, was evaluated in the tests. Data obtained in the tests are used to validate analysis methods. The vibrational/earthquake investigations at the HDR are continuing with the SHAM experiments, planned for the spring of 1988. In these experiments the VKL piping loop will be subjected to direct multiple-point excitation at extremely high levels. The objective is to investigate different pipe support configurations at extreme loading, to establish seismic margins for piping, and to investigate possible failure/plastification modes in an in situ piping system

  20. Mathematical simulation of biologically equivalent doses for LDR-HDR

    International Nuclear Information System (INIS)

    Slosarek, K.; Zajusz, A.

    1996-01-01

    Based on the LQ model examples of biologically equivalent doses LDR, HDR and external beams were calculated. The biologically equivalent doses for LDR were calculated by appending to the LQ model the corrector for the time of repair of radiation sublethal damages. For radiation continuously delivered at a low dose rate the influence of sublethal damage repair time changes on biologically equivalent doses were analysed. For fractionated treatment with high dose rate the biologically equivalent doses were calculated by adding to the LQ model the formula of accelerated repopulation. For total biologically equivalent dose calculation for combine LDR-HDR-Tele irradiation examples are presented with the use of different parameters of the time of repair of sublethal damages and accelerated repopulation. The calculations performed show, that the same biologically equivalent doses can be obtained for different parameters of cell kinetics changes during radiation treatment. It also shows, that during biologically equivalent dose calculations for different radiotherapy schedules, ignorance of cell kinetics parameters can lead to relevant errors

  1. Effectiveness of two different HDR brachytherapy regimens with the same BED value in cervical cancer

    Directory of Open Access Journals (Sweden)

    Rajesh Vashistha

    2010-07-01

    Full Text Available Purpose: To analyze the effectiveness of biologically effective dose (BED in two different regimens of HDR brachytherapy keeping the same total BED to point A and to compare the relationship of overall treatment time in terms of local control and bladder and rectal complications.Material and methods: The study included two groups comprising a total of 90 cervical cancer patients who underwent external beam radiotherapy (EBRT followed by HDR intracavitary brachytherapy (ICBT. EBRT treatment was delivered by a Co-60 teletherapy unit to a prescribed dose of 45 Gy with 1.8 Gy per fraction in 25 fractions over a period of five weeks. Parallel opposed anterior–posterior (AP/PA fields with no central shielding were used, followed by the HDR ICBT dose, to point A, of either two fractions of 9.5 Gy with a gap of 10 days, or three fractions of 7.5 Gy with a gap of 7 days between the fractions. Gemcitabine (dose of 150 mg/m2 was given weekly to all the patients as a radiosensitizer. The calculate BED3 to point A was almost the same in both groups to keep the same late complication rates. The doses, and BED10 and BED3, were calculated at different bladder and rectal point as well as at the lymphatictrapezoid points. During and after treatment patients were evaluated for local control and complications for 24 months.Results and Conclusions: Doses and BEDs at different bladder, rectal and lymphatic trapezoid points, local control, and complications in both HDR ICBT groups did not have statistically significant differences (p > 0.05. Both HDR ICBT schedules are well tolerable and equally effective.

  2. Comparative Analysis between LDR and HDR Images for Automatic Fruit Recognition and Counting

    Directory of Open Access Journals (Sweden)

    Tatiana M. Pinho

    2017-01-01

    Full Text Available Precision agriculture is gaining an increasing interest in the current farming paradigm. This new production concept relies on the use of information technology (IT to provide a control and supervising structure that can lead to better management policies. In this framework, imaging techniques that provide visual information over the farming area play an important role in production status monitoring. As such, accurate representation of the gathered production images is a major concern, especially if those images are used in detection and classification tasks. Real scenes, observed in natural environment, present high dynamic ranges that cannot be represented by the common LDR (Low Dynamic Range devices. However, this issue can be handled by High Dynamic Range (HDR images since they have the ability to store luminance information similarly to the human visual system. In order to prove their advantage in image processing, a comparative analysis between LDR and HDR images, for fruits detection and counting, was carried out. The obtained results show that the use of HDR images improves the detection performance to more than 30% when compared to LDR.

  3. Acute genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Ito, Kazuto; Saitoh, Jun-ichi; Noda, Shin-ei; Harashima, Koichi; Sakurai, Hideyuki; Nakayama, Yuko; Yamamoto, Takumi; Suzuki, Kazuhiro; Nakano, Takashi; Niibe, Hideo

    2005-01-01

    Purpose: Several investigations have revealed that the α/β ratio for prostate cancer is atypically low, and that hypofractionation or high-dose-rate (HDR) brachytherapy regimens using appropriate radiation doses may be expected to yield tumor control and late sequelae rates that are better or at least as favorable as those achieved with conventional radiation therapy. In this setting, we attempted treating localized prostate cancer patients with HDR brachytherapy combined with hypofractionated external beam radiation therapy (EBRT). The purpose of this study was to evaluate the feasibility of using this approach, with special emphasis on the relationship between the severity of acute genitourinary (GU) toxicity and the urethral dose calculated from the dose-volume histogram (DVH) of HDR brachytherapy. Methods and Materials: Between September 2000 and December 2003, 70 patients with localized prostate cancer were treated by iridium-192 HDR brachytherapy combined with hypofractionated EBRT at the Gunma University Hospital. Hypofractionated EBRT was administered in fraction doses of 3 Gy, three times per week; a total dose of 51 Gy was delivered to the prostate gland and the seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography (TRUS)-guided HDR brachytherapy. The fraction size and the number of fractions in HDR brachytherapy were prospectively changed, whereas the total radiation dose for EBRT was fixed at 51 Gy. The fractionation in HDR brachytherapy was as follows: 5 Gy x 5, 7 Gy x 3, 9 Gy x 2, administered twice per day, although the biologic effective dose (BED) for HDR brachytherapy combined with EBRT, assuming that the α/β ratio is 3, was almost equal to 138 in each fractionation group. The planning target volume was defined as the prostate gland with 5-mm margin all around, and the planning was conducted based on

  4. Near constant-time optimal piecewise LDR to HDR inverse tone mapping

    Science.gov (United States)

    Chen, Qian; Su, Guan-Ming; Yin, Peng

    2015-02-01

    In a backward compatible HDR image/video compression, it is a general approach to reconstruct HDR from compressed LDR as a prediction to original HDR, which is referred to as inverse tone mapping. Experimental results show that 2- piecewise 2nd order polynomial has the best mapping accuracy than 1 piece high order or 2-piecewise linear, but it is also the most time-consuming method because to find the optimal pivot point to split LDR range to 2 pieces requires exhaustive search. In this paper, we propose a fast algorithm that completes optimal 2-piecewise 2nd order polynomial inverse tone mapping in near constant time without quality degradation. We observe that in least square solution, each entry in the intermediate matrix can be written as the sum of some basic terms, which can be pre-calculated into look-up tables. Since solving the matrix becomes looking up values in tables, computation time barely differs regardless of the number of points searched. Hence, we can carry out the most thorough pivot point search to find the optimal pivot that minimizes MSE in near constant time. Experiment shows that our proposed method achieves the same PSNR performance while saving 60 times computation time compared to the traditional exhaustive search in 2-piecewise 2nd order polynomial inverse tone mapping with continuous constraint.

  5. An experimental MOSFET approach to characterize (192)Ir HDR source anisotropy.

    Science.gov (United States)

    Toye, W C; Das, K R; Todd, S P; Kenny, M B; Franich, R D; Johnston, P N

    2007-09-07

    The dose anisotropy around a (192)Ir HDR source in a water phantom has been measured using MOSFETs as relative dosimeters. In addition, modeling using the EGSnrc code has been performed to provide a complete dose distribution consistent with the MOSFET measurements. Doses around the Nucletron 'classic' (192)Ir HDR source were measured for a range of radial distances from 5 to 30 mm within a 40 x 30 x 30 cm(3) water phantom, using a TN-RD-50 MOSFET dosimetry system with an active area of 0.2 mm by 0.2 mm. For each successive measurement a linear stepper capable of movement in intervals of 0.0125 mm re-positioned the MOSFET at the required radial distance, while a rotational stepper enabled angular displacement of the source at intervals of 0.9 degrees . The source-dosimeter arrangement within the water phantom was modeled using the standardized cylindrical geometry of the DOSRZnrc user code. In general, the measured relative anisotropy at each radial distance from 5 mm to 30 mm is in good agreement with the EGSnrc simulations, benchmark Monte Carlo simulation and TLD measurements where they exist. The experimental approach employing a MOSFET detection system of small size, high spatial resolution and fast read out capability allowed a practical approach to the determination of dose anisotropy around a HDR source.

  6. Towards real-time 3D ultrasound planning and personalized 3D printing for breast HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Poulin, Eric; Gardi, Lori; Fenster, Aaron; Pouliot, Jean; Beaulieu, Luc

    2015-01-01

    Two different end-to-end procedures were tested for real-time planning in breast HDR brachytherapy treatment. Both methods are using a 3D ultrasound (3DUS) system and a freehand catheter optimization algorithm. They were found fast and efficient. We demonstrated a proof-of-concept approach for personalized real-time guidance and planning to breast HDR brachytherapy treatments

  7. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    International Nuclear Information System (INIS)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus; Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf

    2015-01-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [de

  8. SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

    International Nuclear Information System (INIS)

    Li, J S; Ma, C

    2014-01-01

    Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system was used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use

  9. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  10. The effect of split pixel HDR image sensor technology on MTF measurements

    Science.gov (United States)

    Deegan, Brian M.

    2014-03-01

    Split-pixel HDR sensor technology is particularly advantageous in automotive applications, because the images are captured simultaneously rather than sequentially, thereby reducing motion blur. However, split pixel technology introduces artifacts in MTF measurement. To achieve a HDR image, raw images are captured from both large and small sub-pixels, and combined to make the HDR output. In some cases, a large sub-pixel is used for long exposure captures, and a small sub-pixel for short exposures, to extend the dynamic range. The relative size of the photosensitive area of the pixel (fill factor) plays a very significant role in the output MTF measurement. Given an identical scene, the MTF will be significantly different, depending on whether you use the large or small sub-pixels i.e. a smaller fill factor (e.g. in the short exposure sub-pixel) will result in higher MTF scores, but significantly greater aliasing. Simulations of split-pixel sensors revealed that, when raw images from both sub-pixels are combined, there is a significant difference in rising edge (i.e. black-to-white transition) and falling edge (white-to-black) reproduction. Experimental results showed a difference of ~50% in measured MTF50 between the falling and rising edges of a slanted edge test chart.

  11. Anatomy-based inverse planning dose optimization in HDR prostate implant: A toxicity study

    International Nuclear Information System (INIS)

    Mahmoudieh, Alireza; Tremblay, Christine; Beaulieu, Luc; Lachance, Bernard; Harel, Francois; Lessard, Etienne; Pouliot, Jean; Vigneault, Eric

    2005-01-01

    Background and purpose: The aim of this study is to evaluate the acute and late complications in patients who have received HDR implant boost using inverse planning, and to determine dose volume correlations. Patients and methods: Between September 1999 and October 2002, 44 patients with locally advanced prostate cancer (PSA ≥10 ng/ml, and/or Gleason score ≥7, and/or Stage T2c or higher) were treated with 40-45 Gy external pelvic field followed by 2-3 fraction of inverse-planned HDR implant boost (6-9.5 Gy /fraction). Median follow-up time was 1.7 years with 81.8% of patients who had at least 12 months of follow up (range 8.6-42.5. Acute and late morbidity data were collected and graded according to RTOG criteria. Questionnaires were used to collect prostate related measures of quality of life, and international prostate symptom score (IPSS) before and after treatment. Dose-volume histograms for prostate, urethra, bladder, penis bulb and rectum were analyzed. Results: The median patient age was 64 years. Of these, 32% were in the high risk group, and 61% in the intermediate risk group. 3 patients (7%) had no adverse prognostic factors. A single grade 3 GU acute toxicity was reported but no grade 3-4 acute GI toxicity. No grade 3-4 late GU or GI toxicity was reported. Acute (late) grade 2 urinary and rectal symptoms were reported in 31.8 (11.4%) and 4.6% (4.6%) of patients, respectively. A trend for predicting acute GU toxicity is seen for total HDR dose of more than 18 Gy (OR=3.6, 95%CI=[0.96-13.5], P=0.058). The evolution of toxicity is presented for acute and late GU/GI toxicity. Erectile dysfunction occurs in approximately 27% of patients who were not on hormonal deprivation, but may be taking sildenafil. The IPSS peaked on averaged 6 weeks post-implant and returned to the baseline at a median of 6 months. Conclusions: Inverse-planned HDR brachytherapy is a viable option to deliver higher dose to the prostate as a boost without increasing GU or rectal

  12. A novel GATA3 nonsense mutation in a newly diagnosed adult patient of hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome.

    Science.gov (United States)

    Nanba, Kazutaka; Usui, Takeshi; Nakamura, Michikazu; Toyota, Yuko; Hirota, Keisho; Tamanaha, Tamiko; Kawashima, Sachiko-Tsukamoto; Nakao, Kanako; Yuno, Akiko; Tagami, Tetsuya; Naruse, Mitsuhide; Shimatsu, Akira

    2013-01-01

    Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by a GATA3 gene mutation. Here we report a novel mutation of GATA3 in a patient diagnosed with HDR syndrome at the age of 58 with extensive intracranial calcification. A 58-year-old Japanese man showed severe hypocalcemia and marked calcification in the basal ganglia, cerebellum, deep white matter, and gray-white junction on computed tomography (CT). The serum intact parathyroid hormone level was relatively low against low serum calcium concentration. The patient had been diagnosed with bilateral sensorineural deafness in childhood and had a family history of hearing disorders. Imaging studies revealed no renal anomalies. The patient was diagnosed with HDR syndrome, and genetic testing was performed. Genetic analysis of GATA3 showed a novel nonsense mutation at codon 198 (S198X) in exon 3. The S198X mutation leads to a loss of two zinc finger deoxyribonucleic acid (DNA) binding domains and is considered to be responsible for HDR syndrome. We identified a novel nonsense mutation of GATA3 in an adult patient with HDR syndrome who showed extensive intracranial calcification.

  13. HDR IMAGING FOR FEATURE DETECTION ON DETAILED ARCHITECTURAL SCENES

    Directory of Open Access Journals (Sweden)

    G. Kontogianni

    2015-02-01

    Full Text Available 3D reconstruction relies on accurate detection, extraction, description and matching of image features. This is even truer for complex architectural scenes that pose needs for 3D models of high quality, without any loss of detail in geometry or color. Illumination conditions influence the radiometric quality of images, as standard sensors cannot depict properly a wide range of intensities in the same scene. Indeed, overexposed or underexposed pixels cause irreplaceable information loss and degrade digital representation. Images taken under extreme lighting environments may be thus prohibitive for feature detection/extraction and consequently for matching and 3D reconstruction. High Dynamic Range (HDR images could be helpful for these operators because they broaden the limits of illumination range that Standard or Low Dynamic Range (SDR/LDR images can capture and increase in this way the amount of details contained in the image. Experimental results of this study prove this assumption as they examine state of the art feature detectors applied both on standard dynamic range and HDR images.

  14. Fricke gel-layer dosimetry in HDR brachytherapy

    International Nuclear Information System (INIS)

    Gambarini, G.; Negri, A.; Carrara, M.; Marchesini, R.

    2008-01-01

    Full text: In the last decade, technological improvements in radiotherapy have been significant and consequently the use and importance of radiotherapy in cancer treatment have increased greatly. In brachytherapy, new possibilities have been opened by the impressive progresses in 3D imaging, by the development of sophisticated techniques for modern afterloaders and by the constantly increasing speed and capacity of computers. However, these methodological improvements require corresponding improvements in the dosimetry methods, in order to ensure that the values calculated with computer treatment planning systems, adopted in the clinical praxis, agree with the delivered dose distributions. Fricke gel-layer dosimeters (FGLD) are under study by our group as a reliable alternative to films, semiconductors arrays or thermoluminescent dosimeters (TLDs). In the last years, we have significantly improved this technique by defining the FGLD best chemical composition, by optimizing the image acquisition assessment and by developing a dedicated software for image analysis. In this study, experimental measurements of planar dose distributions of a clinical 192 Ir source (Microselectron HDR, Nucletron) obtained by irradiating a series of piled-up FGL dosimeters in a tissue-equivalent phantom are presented. The obtained results were in accordance to TLD measurements and to treatment planning system (Plato, Nucletron) calculations. FGLD have proven to be a reliable tool to achieve HDR brachytherapy dose distribution measurements

  15. Characterization of HDR Ir-192 source for 3D planning system

    International Nuclear Information System (INIS)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D.; Rubo, Rodrigo; Ferreira, Louise A.

    2011-01-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  16. Characterization of HDR Ir-192 source for 3D planning system

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D., E-mail: gabriel.fonseca@usp.b, E-mail: hyoriyaz@ipen.b, E-mail: ptsiquei@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rubo, Rodrigo [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia; Minamisawa, Renato A., E-mail: renato.minamisawa@psi.c [Paul Scherrer Institut (PSI), Villigen (Switzerland); Ferreira, Louise A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Fac. de Medicina

    2011-07-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  17. SU-E-J-270: Study of PET Response to HDR Brachytherapy of Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, R; Le, Y; Armour, E; Efron, J; Azad, N; Wahl, R; Gearhart, S; Herman, J [Johns Hopkins University, Baltimore, MD (United States)

    2014-06-01

    Purpose: Dose-response studies in radiation therapy are typically using single response values for tumors across ensembles of tumors. Using the high dose rate (HDR) treatment plan dose grid and pre- and post-therapy FDG-PET images, we look for correlations between voxelized dose and FDG uptake response in individual tumors. Methods: Fifteen patients were treated for localized rectal cancer using 192Ir HDR brachytherapy in conjunction with surgery. FDG-PET images were acquired before HDR therapy and 6–8 weeks after treatment (prior to surgery). Treatment planning was done on a commercial workstation and the dose grid was calculated. The two PETs and the treatment dose grid were registered to each other using non-rigid registration. The difference in PET SUV values before and after HDR was plotted versus absorbed radiation dose for each voxel. The voxels were then separated into bins for every 400 cGy of absorbed dose and the bin average values plotted similarly. Results: Individual voxel doses did not correlate with PET response; however, when group into tumor subregions corresponding to dose bins, eighty percent of the patients showed a significant positive correlation (R2 > 0) between PET uptake difference in the targeted region and the absorbed dose. Conclusion: By considering larger ensembles of voxels, such as organ average absorbed dose or the dose bins considered here, valuable information may be obtained. The dose-response correlations as measured by FDG-PET difference potentially underlines the importance of FDG-PET as a measure of response, as well as the value of voxelized information.

  18. Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-year Disease-free Survival and Toxicity Observations

    Directory of Open Access Journals (Sweden)

    Donald Blake Fuller

    2014-11-01

    Full Text Available PURPOSEProstate stereotactic body radiotherapy (SBRT may substantially recapitulate the dose distribution of high-dose-rate (HDR brachytherapy, representing an externally delivered Virtual HDR treatment method. Herein we present 5-year outcomes from a cohort of consecutively treated Virtual HDR SBRT prostate cancer patients.METHODSSeventy-nine patients were treated from 2006 - 2009, 40 low-risk and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in 4 fractions. The planning target volume (PTV included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered > 95% of the PTV (V100 >= 95%, with a minimum 150% PTV dose escalation to create HDR-like PTV dose distribution.RESULTSMedian pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70% but only 3 of them subsequently relapsed, Biochemical-relapse-free survival was 100% and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98% and 92% by Phoenix definition. Local relapse did not occur, distant metastasis-free survival was 100% and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10% and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0% and 1%, respectively, with no grade 3 or higher toxicity. Of patients potent pre-SBRT, 65% remained so at 5 years.CONCLUSIONSVirtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

  19. Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir

    Directory of Open Access Journals (Sweden)

    Tarcísio Passos Ribeiro de Campos

    2016-04-01

    Full Text Available Abstract Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods: Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice.

  20. Independent verification of the delivered dose in High-Dose Rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Portillo, P.; Feld, D.; Kessler, J.

    2009-01-01

    An important aspect of a Quality Assurance program in Clinical Dosimetry is an independent verification of the dosimetric calculation done by the Treatment Planning System for each radiation treatment. The present paper is aimed at creating a spreadsheet for the verification of the dose recorded at a point of an implant with radioactive sources and HDR in gynecological injuries. An 192 Ir source automatic differed loading equipment, GammaMedplus model, Varian Medical System with HDR installed at the Angel H. Roffo Oncology Institute has been used. The planning system implemented for getting the dose distribution is the BraquiVision. The sources coordinates as well as those of the calculation point (Rectum) are entered into the Excel-devised verification program by assuming the existence of a point source in each one of the applicators' positions. Such calculation point has been selected as the rectum is an organ at risk, therefore determining the treatment planning. The dose verification is performed at points standing at a sources distance having at least twice the active length of such sources, so they may be regarded as point sources. Most of the sources used in HDR brachytherapy with 192 Ir have a 5 mm active length for all equipment brands. Consequently, the dose verification distance must be at least of 10 mm. (author)

  1. Evaluation of water-mimicking solid phantom materials for use in HDR and LDR brachytherapy dosimetry

    Science.gov (United States)

    Schoenfeld, Andreas A.; Thieben, Maike; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2017-12-01

    In modern HDR or LDR brachytherapy with photon emitters, fast checks of the dose profiles generated in water or a water-equivalent phantom have to be available in the interest of patient safety. However, the commercially available brachytherapy photon sources cover a wide range of photon emission spectra, and the range of the in-phantom photon spectrum is further widened by Compton scattering, so that the achievement of water-mimicking properties of such phantoms involves high requirements on their atomic composition. In order to classify the degree of water equivalence of the numerous commercially available solid water-mimicking phantom materials and the energy ranges of their applicability, the radial profiles of the absorbed dose to water, D w, have been calculated using Monte Carlo simulations in these materials and in water phantoms of the same dimensions. This study includes the HDR therapy sources Nucletron Flexisource Co-60 HDR (60Co), Eckert und Ziegler BEBIG GmbH CSM-11 (137Cs), Implant Sciences Corporation HDR Yb-169 Source 4140 (169Yb) as well as the LDR therapy sources IsoRay Inc. Proxcelan CS-1 (131Cs), IsoAid Advantage I-125 IAI-125A (125I), and IsoAid Advantage Pd-103 IAPd-103A (103Pd). Thereby our previous comparison between phantom materials and water surrounding a Varian GammaMed Plus HDR therapy 192Ir source (Schoenfeld et al 2015) has been complemented. Simulations were performed in cylindrical phantoms consisting of either water or the materials RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, Plastic Water LR, Original Plastic Water (2015), Plastic Water (1995), Blue Water, polyethylene, polystyrene and PMMA. While for 192Ir, 137Cs and 60Co most phantom materials can be regarded as water equivalent, for 169Yb the materials Plastic Water LR, Plastic Water DT and RW1 appear as water equivalent. For the low-energy sources 106Pd, 131Cs and 125I, only Plastic Water LR can be classified as water equivalent.

  2. HDR brachytherapy in carcinoma of cervix: initial experience at AWARE hospitals

    International Nuclear Information System (INIS)

    Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

    2002-01-01

    High dose rate (HDR) brachytherapy is well established in the management of gynaecological malignancies. A report on the initial results of one and half year experience with a consistent dose/fractionation schedule and procedure of planning with delivery of treatment schedule is presented

  3. Realistic camera noise modeling with application to improved HDR synthesis

    Science.gov (United States)

    Goossens, Bart; Luong, Hiêp; Aelterman, Jan; Pižurica, Aleksandra; Philips, Wilfried

    2012-12-01

    Due to the ongoing miniaturization of digital camera sensors and the steady increase of the "number of megapixels", individual sensor elements of the camera become more sensitive to noise, even deteriorating the final image quality. To go around this problem, sophisticated processing algorithms in the devices, can help to maximally exploit the knowledge on the sensor characteristics (e.g., in terms of noise), and offer a better image reconstruction. Although a lot of research focuses on rather simplistic noise models, such as stationary additive white Gaussian noise, only limited attention has gone to more realistic digital camera noise models. In this article, we first present a digital camera noise model that takes several processing steps in the camera into account, such as sensor signal amplification, clipping, post-processing,.. We then apply this noise model to the reconstruction problem of high dynamic range (HDR) images from a small set of low dynamic range (LDR) exposures of a static scene. In literature, HDR reconstruction is mostly performed by computing a weighted average, in which the weights are directly related to the observer pixel intensities of the LDR image. In this work, we derive a Bayesian probabilistic formulation of a weighting function that is near-optimal in the MSE sense (or SNR sense) of the reconstructed HDR image, by assuming exponentially distributed irradiance values. We define the weighting function as the probability that the observed pixel intensity is approximately unbiased. The weighting function can be directly computed based on the noise model parameters, which gives rise to different symmetric and asymmetric shapes when electronic noise or photon noise is dominant. We also explain how to deal with the case that some of the noise model parameters are unknown and explain how the camera response function can be estimated using the presented noise model. Finally, experimental results are provided to support our findings.

  4. : Light Steering Projection Systems and Attributes for HDR Displays

    KAUST Repository

    Damberg, Gerwin

    2017-06-02

    New light steering projectors in cinema form images by moving light away from dark regions into bright areas of an image. In these systems, the peak luminance of small features can far exceed full screen white luminance. In traditional projectors where light is filtered or blocked in order to give shades of gray (or colors), the peak luminance is fixed. The luminance of chromatic features benefit in the same way as white features, and chromatic image details can be reproduced at high brightness leading to a much wider overall color gamut coverage than previously possible. Projectors of this capability are desired by the creative community to aid in and enhance storytelling. Furthermore, reduced light source power requirements of light steering projectors provide additional economic and environmental benefits. While the dependency of peak luminance level on (bright) image feature size is new in the digital cinema space, display technologies with identical characteristics such as OLED, LED LCD and Plasma TVs are well established in the home. Similarly, direct view LED walls are popular in events, advertising and architectural markets. To enable consistent color reproduction across devices in today’s content production pipelines, models that describe modern projectors and display attributes need to evolve together with HDR standards and available metadata. This paper is a first step towards rethinking legacy display descriptors such as contrast, peak luminance and color primaries in light of new display technology. We first summarize recent progress in the field of light steering projectors in cinema and then, based on new projector and existing display characteristics propose the inclusion of two simple display attributes: Maximum Average Luminance and Peak (Color) Primary Luminance. We show that the proposed attributes allow a better prediction of content reproducibility on HDR displays. To validate this assertion, we test professional content on a commercial HDR

  5. Clinical implementation of a new HDR brachytherapy device for partial breast irradiation

    International Nuclear Information System (INIS)

    Scanderbeg, Daniel J.; Yashar, Catheryn; Rice, Roger; Pawlicki, Todd

    2009-01-01

    Purpose: To present the clinical implementation of a new HDR device for partial breast irradiation, the Strut-Adjusted Volume Implant (SAVI), at the University of California, San Diego. Methods and materials: The SAVI device has multiple peripheral struts that can be differentially loaded with the HDR source. Planning criteria used for evaluation of the treatment plans included the following dose volume histogram (DVH) criteria: V90 >90%, V150 <50 cc and V200 <20 cc. Results: SAVI has been used on 20 patients to date at UC San Diego. In each case, the dose was modulated according to patient-specific anatomy to cover the tumor bed, while sparing normal tissues. The dosimetric data show that we can achieve greater than 90% coverage with respect to V90 (median of 95.3%) and also keep a low V150 and V200 dose at 24.5 and 11.2 cc, respectively. Complete treatment can be done within a 30-min time slot, which includes implant verification, setup, and irradiation time as well as wound dressing. Conclusion: SAVI has been implemented at UC San Diego for accelerated partial breast irradiation with excellent tumor bed conformance and minimal normal tissue exposure. Patient positioning is the key to identifying any inter-fraction device motion. Device asymmetry or tissue conformance has been shown to resolve itself 24 h after the device implantation. The device can be implemented into an existing HDR program with minimal effort

  6. Photometric and Colorimeric Comparison of HDR and Spctrally Resolved Rendering Images

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Soreze, Thierry Silvio Claude; Thorseth, Anders

    2017-01-01

    In this paper, we will demonstrate a comparison between measured colorimetric images, and simulated images from a physics based rendering engine. The colorimetric images are high dynamic range (HDR) and taken with a luminance and colour camera mounted on a goniometer. For the comparison, we have ...

  7. Evaluation of the Kerma at the entrance of the labyrin thin in facilities with Co-60 HDR brachytherapy

    International Nuclear Information System (INIS)

    Pujades, M. C.; Granero, D.; Ballester, F.; Perez-Calatayud, J.; Vijande, J.

    2013-01-01

    The purpose of this study is to evaluate the kerma's collision at the entrance of the labyrinth adapting the methodology of the NCRP-151 to a bunker of brachytherapy with Co-60, similar to the one carried out in a previous work with HDR Ir-192. To validate the result is simulated using techniques Monte Carlo (MC) two typical designs of HDR with Co-60 bunker. (Author)

  8. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    International Nuclear Information System (INIS)

    Reyes-Rivera, E.; Sosa, M.; Reyes, U.; Jesús Bernal-Alvarado, José de; Córdova, T.; Gil-Villegas, A.; Monzón, E.

    2014-01-01

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy

  9. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Rivera, E., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Sosa, M., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Reyes, U., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Jesús Bernal-Alvarado, José de, E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Córdova, T., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Gil-Villegas, A., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx [División de Ciencias e Ingenierías, Universidad de Guanajuato, 37150 León, Gto. (Mexico); Monzón, E., E-mail: emonzon@imss.gob.mx [Unidad de Alta Especialidad No.1, Instituto Mexicano del Seguro Social, Léon, Gto. (Mexico)

    2014-11-07

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy.

  10. 3-D conformal HDR brachytherapy as monotherapy for localized prostate cancer. A pilot study

    International Nuclear Information System (INIS)

    Martin, T.; Baltas, D.; Kurek, R.; Roeddiger, S.; Kontova, M.; Anagnostopoulos, G.; Skazikis, G.; Zamboglou, N.; Dannenberg, T.; Buhleier, T.; Tunn, U.

    2004-01-01

    Purpose: pilot study to evaluate feasibility, acute toxicity and conformal quality of three-dimensional (3-D) conformal high-dose-rate (HDR) brachytherapy as monotherapy for localized prostate cancer using intraoperative real-time planning. Patients and methods: between 05/2002 and 05/2003, 52 patients with prostate cancer, prostate-specific antigen (PSA) ≤ 10 ng/ml, Gleason score ≤ 7 and clinical stage ≤ T2a were treated. Median PSA was 6.4 ng/ml and median Gleason score 5. 24/52 patients had stage T1c and 28/52 stage T2a. For transrectal ultrasound-(TRUS-)guided transperineal implantation of flexible plastic needles into the prostate, the real-time HDR planning system SWIFT trademark was used. After implantation, CT-based 3-D postplanning was performed. All patients received one implant for four fractions of HDR brachytherapy in 48 h using a reference dose (D ref ) of 9.5 Gy to a total dose of 38.0 Gy. Dose-volume histograms (DVHs) were analyzed to evaluate the conformal quality of each implant using D 90 , D 10 urethra, and D 10 rectum. Acute toxicity was evaluated using the CTC (common toxicity criteria) scales. Results: median D 90 was 106% of D ref (range: 93-115%), median D 10 urethra 159% of D ref (range: 127-192%), and median D 10 rectum 55% of D ref (range: 35-68%). Median follow-up is currently 8 months. In 2/52 patients acute grade 3 genitourinary toxicity was observed. No gastrointestinal toxicity > grade 1 occurred. Conclusion: 3-D conformal HDR brachytherapy as monotherapy using intraoperative real-time planning is a feasible and highly conformal treatment for localized prostate cancer associated with minimal acute toxicity. Longer follow-up is needed to evaluate late toxicity and biochemical control. (orig.)

  11. IPIP: A new approach to inverse planning for HDR brachytherapy by directly optimizing dosimetric indices

    International Nuclear Information System (INIS)

    Siauw, Timmy; Cunha, Adam; Atamtuerk, Alper; Hsu, I-Chow; Pouliot, Jean; Goldberg, Ken

    2011-01-01

    Purpose: Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is found. In this way, the dose distribution is controlled by abstract parameters. The purpose of this study is to develop a new approach for HDR brachytherapy by directly optimizing the dose distribution based on dosimetric criteria. Methods: The authors developed inverse planning by integer program (IPIP), an optimization model for computing HDR brachytherapy dose plans and a fast heuristic for it. They used their heuristic to compute dose plans for 20 anonymized prostate cancer image data sets from patients previously treated at their clinic database. Dosimetry was evaluated and compared to dosimetric criteria. Results: Dose plans computed from IPIP satisfied all given dosimetric criteria for the target and healthy tissue after a single iteration. The average target coverage was 95%. The average computation time for IPIP was 30.1 s on an Intel(R) Core TM 2 Duo CPU 1.67 GHz processor with 3 Gib RAM. Conclusions: IPIP is an HDR brachytherapy planning system that directly incorporates dosimetric criteria. The authors have demonstrated that IPIP has clinically acceptable performance for the prostate cases and dosimetric criteria used in this study, in both dosimetry and runtime. Further study is required to determine if IPIP performs well for a more general group of patients and dosimetric criteria, including other cancer sites such as GYN.

  12. Observation and simulation of non-laminar flow phenomena at the HDR site near Soulth-sous-forets; Beobachtung und Simulation von nicht-laminarem Fliessverhalten am HDR-Standort Soultz

    Energy Technology Data Exchange (ETDEWEB)

    Kohl, T [ETH Hoenggerberg, Zuerich (Switzerland). Inst. fuer Geophysik; Evans, K F; Hopkirk, R J [Polydynamics Engineering, Maennedorf (Switzerland); Jung, R [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Rybach, L [ETH Hoenggerberg, Zuerich (Switzerland). Inst. fuer Geophysik und Radiometrie

    1997-12-01

    Three independent multi-rate flow experiments were conducted in 1994 and 1995 in the open hole depth interval of a wellbore at the Hot-Dry-Rocks (HDR) test site Soultz. The steady state and transient dowmhole pressure records gave clear indications of non-Darcian flow. A numerical model has been set-up to evaluate these two measurements. An excellent fit of the transient pressure responses of all three flow tests could be achieved by assuming a simple model geometry. The models predict fluid transport along a conduit with substantial surface area in which fully-turbulent flow is occurring. The parameters required by our best-fit simulation all fall into a physically reasonable range. Sensitivity analysis demonstrates a non-Darcian flow regime along highly conductive features. The existence of high capacity far-field faults as postulated in our model confirms earlier characterisations of the Soultz test site. (orig.) [Deutsch] In den Jahren 1994 und 1995 wurden drei unabhaengige Druck- bzw. Fliessratentests in den Bohrungen GPK1 und GPK2 des HDR Standortes Soultz durchgefuehrt. Sowohl die stationaeren wie auch die instationaeren Druckaufzeichnungen gaben bereits klare Hinweise auf nichtlaminare, turbulent-aehnliche Stroemungsverhaeltnisse. Zur genaueren Interpretation dieser Daten wurde das numerische Programm FRACTure erweitert. Unter der Annahme eines geometrisch einfachen Modells konnten die instationaeren Druckantworten sehr gut angepasst werden. Es gelang sogar, die beiden in GPK1 durchgefuehrten Tests durch dieselben Modelle zu erklaeren. Die hierfuer benoetigten Modellparameter liegen in einem physikalisch sinnvollem Rahmen und bestaetigen z.T. fruehere Untersuchungen. Die Existenz grosser Stoerungszonen, welche von den Modellen vorausgesetzt werden, bestaetigt ebenfalls fruehere Charakterisierungen des HDR Standortes Soultz als ein teilweise offenes hydraulisches System. (orig.)

  13. Quality control and performance evaluation of microselectron HDR machine over 30 months

    International Nuclear Information System (INIS)

    Balasubramanian, N.; Annex, E.H.; Sunderam, N.; Patel, N.P.; Kaushal, V.

    2008-01-01

    To assess the performance evaluation of Microselectron HDR machine the standard quality control and quality assurance checks were carried out after each loading of new 192 Ir brachytherapy source In the machine. Total 9 loadings were done over a period of 30 months

  14. Impact of using linear optimization models in dose planning for HDR brachytherapy

    International Nuclear Information System (INIS)

    Holm, Aasa; Larsson, Torbjoern; Carlsson Tedgren, Aasa

    2012-01-01

    Purpose: Dose plans generated with optimization models hitherto used in high-dose-rate (HDR) brachytherapy have shown a tendency to yield longer dwell times than manually optimized plans. Concern has been raised for the corresponding undesired hot spots, and various methods to mitigate these have been developed. The hypotheses upon this work is based are (a) that one cause for the long dwell times is the use of objective functions comprising simple linear penalties and (b) that alternative penalties, as these are piecewise linear, would lead to reduced length of individual dwell times. Methods: The characteristics of the linear penalties and the piecewise linear penalties are analyzed mathematically. Experimental comparisons between the two types of penalties are carried out retrospectively for a set of prostate cancer patients. Results: When the two types of penalties are compared, significant changes can be seen in the dwell times, while most dose-volume parameters do not differ significantly. On average, total dwell times were reduced by 4.2%, with a reduction of maximum dwell times by 25%, when the alternative penalties were used. Conclusions: The use of linear penalties in optimization models for HDR brachytherapy is one cause for the undesired long dwell times that arise in mathematically optimized plans. By introducing alternative penalties, a significant reduction in dwell times can be achieved for HDR brachytherapy dose plans. Although various measures for mitigating the long dwell times are already available, the observation that linear penalties contribute to their appearance is of fundamental interest.

  15. Balloon-based adjuvant radiotherapy in breast cancer: comparison between {sup 99m}Tc and HDR {sup 192}Ir

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Tarcisio Passos Ribeiro de; Lima, Carla Flavia de; Cuperschmid, Ethel Mizrahy, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2016-03-15

    Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with {sup 99m}Tc and balloon brachytherapy with high-dose-rate (HDR) {sup 192}Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and methods: simulations of implants with {sup 99m}Tc-filled and HDR {sup 192}Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: the {sup 99m}Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h{sup -1}.mCi{sup -1} and 0.190 cGyh{sup -1} at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh{sup -1}.mCi{sup -1}, respectively, for the HDR {sup 192}Ir balloon. An exposure time of 24 hours was required for the {sup 99m}Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR {sup 192}Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: temporary {sup 99m}Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR {sup 192}Ir balloon implantation, which is the current standard in clinical practice. (author)

  16. SU-F-P-42: “To Navigate, Or Not to Navigate: HDR BT in Recurrent Spine Lesions”

    Energy Technology Data Exchange (ETDEWEB)

    Voros, L; Cohen, G; Zaider, M; Yamada, Y [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2016-06-15

    Purpose: We compare the accuracy of HDR catheter placement for paraspinal lesions using O-arm CBCT imaging combined with StealthStation navigation and traditional fluoroscopically guided catheter placement. Methods: CT and MRI scans were acquired pre-treatment to outline the lesions and design treatment plans (pre-plans) to meet dosimetric constrains. The pre-planned catheter trajectories were transferred into the StealthStation Navigation system prior to the surgery. The StealthStation is an infra red (IR) optical navigation system used for guidance of surgical instruments. An intraoperative CBCT scan (O-arm) was acquired with reference IR optical fiducials anchored onto the patient and registered with the preplan image study to guide surgical instruments in relation to the patients’ anatomy and to place the brachytherapy catheters along the pre-planned trajectories. The final treatment plan was generated based on a 2nd intraoperative CBCT scan reflecting achieved implant geometry. The 2nd CBCT was later registered with the initial CT scan to compare the preplanned dwell positions with actual dwell positions (catheter placements). Similar workflow was used in placement of 8 catheters (1 patient) without navigation, but under fluoroscopy guidance in an interventional radiology suite. Results: A total of 18 catheters (3 patients) were placed using navigation assisted surgery. Average displacement of 0.66 cm (STD=0.37cm) was observed between the pre-plan source positions and actual source positions in the 3 dimensional space. This translates into an average 0.38 cm positioning error in one direction including registration errors, digitization errors, and the surgeons ability to follow the planned trajectory. In comparison, average displacement of non-navigated catheters was 0.50 cm (STD=0.22cm). Conclusion: Spinal lesion HDR brachytherapy planning is a difficult task. Catheter placement has a direct impact on target coverage and dose to critical structures. While

  17. Relocation of a nucletron microselectron-HDR brachytherapy system

    Energy Technology Data Exchange (ETDEWEB)

    Bartrum, T; Tran, T; Freeman, N; Morales, J [St Vincents Hospital, Darlinghurst, NSW (Australia)

    2004-12-15

    Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

  18. Relocation of a nucletron microselectron-HDR brachytherapy system

    International Nuclear Information System (INIS)

    Bartrum, T.; Tran, T.; Freeman, N.; Morales, J.

    2004-01-01

    Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

  19. Results of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) in treatment of obstructive endobronchial non-small cell lung cancer

    Science.gov (United States)

    Weinberg, Benjamin D.; Allison, Ron R.; Sibata, Claudio; Parent, Teresa; Downie, Gordon

    2009-06-01

    We reviewed the outcome of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) for patients with symptomatic obstruction from endobronchial non-small cell lung cancer. Methods: Nine patients who received combined PDT and HDR for endobronchial cancers were identified and their charts reviewed. The patients were eight males and one female aged 52-73 at diagnosis, initially presenting with various stages of disease: stage IA (N=1), stage IIA (N=1), stage III (N=6), and stage IV (N=1). Intervention was with HDR (500 cGy to 5 mm once weekly for 3 weeks) and PDT (2 mg/kg Photofrin, followed by 200 J/cm2 illumination 48 hours post infusion). Treatment group 1 (TG-1, N=7) received HDR first; Treatment group 2 (TG-2, N=2) received PDT first. Patients were followed by regular bronchoscopies. Results: Treatments were well tolerated, all patients completed therapy, and none were lost to follow-up. In TG-1, local tumor control was achieved in six of seven patients for: 3 months (until death), 15 months, 2+ years (until death), 2+ years (ongoing), and 5+ years (ongoing, N=2). In TG-2, local control was achieved in only one patient, for 84 days. Morbidities included: stenosis and/or other reversible benign local tissue reactions (N=8); photosensitivity reaction (N=2), and self-limited pleural effusion (N=2). Conclusions: Combined HDR/PDT treatment for endobronchial tumors is well tolerated and can achieve prolonged local control with acceptable morbidity when PDT follows HDR and when the spacing between treatments is one month or less. This treatment regimen should be studied in a larger patient population.

  20. High Brightness HDR Projection Using Dynamic Freeform Lensing

    KAUST Repository

    Damberg, Gerwin

    2016-05-03

    Cinema projectors need to compete with home theater displays in terms of image quality. High frame rate and spatial resolution as well as stereoscopic 3D are common features today, but even the most advanced cinema projectors lack in-scene contrast and, more important, high peak luminance, both of which are essential perceptual attributes of images appearing realistic. At the same time, HDR image statistics suggest that the average image intensity in a controlled ambient viewing environment such as the cinema can be as low as 1% for cinematic HDR content and not often higher than 18%, middle gray in photography. Traditional projection systems form images and colors by blocking the source light from a lamp, therefore attenuating between 99% and 82% of light, on average. This inefficient use of light poses significant challenges for achieving higher peak brightness levels. In this work, we propose a new projector architecture built around commercially available components, in which light can be steered to form images. The gain in system efficiency significantly reduces the total cost of ownership of a projector (fewer components and lower operating cost), and at the same time increases peak luminance and improves black level beyond what is practically achievable with incumbent projector technologies. At the heart of this computational display technology is a new projector hardware design using phase modulation in combination with a new optimization algorithm that is capable of on-the-fly computation of freeform lens surfaces. © 2016 ACM.

  1. The Ansel Adams zone system: HDR capture and range compression by chemical processing

    Science.gov (United States)

    McCann, John J.

    2010-02-01

    We tend to think of digital imaging and the tools of PhotoshopTM as a new phenomenon in imaging. We are also familiar with multiple-exposure HDR techniques intended to capture a wider range of scene information, than conventional film photography. We know about tone-scale adjustments to make better pictures. We tend to think of everyday, consumer, silver-halide photography as a fixed window of scene capture with a limited, standard range of response. This description of photography is certainly true, between 1950 and 2000, for instant films and negatives processed at the drugstore. These systems had fixed dynamic range and fixed tone-scale response to light. All pixels in the film have the same response to light, so the same light exposure from different pixels was rendered as the same film density. Ansel Adams, along with Fred Archer, formulated the Zone System, staring in 1940. It was earlier than the trillions of consumer photos in the second half of the 20th century, yet it was much more sophisticated than today's digital techniques. This talk will describe the chemical mechanisms of the zone system in the parlance of digital image processing. It will describe the Zone System's chemical techniques for image synthesis. It also discusses dodging and burning techniques to fit the HDR scene into the LDR print. Although current HDR imaging shares some of the Zone System's achievements, it usually does not achieve all of them.

  2. Westinghouse-GOTHIC distributed parameter modelling for HDR test E11.2

    International Nuclear Information System (INIS)

    Narula, J.S.; Woodcock, J.

    1994-01-01

    The Westinghouse-GOTHIC (WGOTHIC) code is a sophisticated mathematical computer code designed specifically for the thermal hydraulic analysis of nuclear power plant containment and auxiliary buildings. The code is capable of sophisticated flow analysis via the solution of mass, momentum, and energy conservation equations. Westinghouse has investigated the use of subdivided noding to model the flow patterns of hydrogen following its release into a containment atmosphere. For the investigation, several simple models were constructed to represent a scale similar to the German HDR containment. The calculational models were simplified to test the basic capability of the plume modeling methods to predict stratification while minimizing the number of parameters. A large empty volume was modeled, with the same volume and height as HDR. A scenario was selected that would be expected to stably stratify, and the effects of noding on the prediction of stratification was studied. A single phase hot gas was injected into the volume at a height similar to that of HDR test E11.2, and there were no heat sinks modeled. Helium was released into the calculational models, and the resulting flow patterns were judged relative to the expected results. For each model, only the number of subdivisions within the containment volume was varied. The results of the investigation of noding schemes has provided evidence of the capability of subdivided (distributed parameter) noding. The results also showed that highly inaccurate flow patterns could be obtained by using an insufficient number of subdivided nodes. This presents a significant challenge to the containment analyst, who must weigh the benefits of increased noding with the penalties the noding may incur on computational efficiency. Clearly, however, an incorrect noding choice may yield erroneous results even if great care has been taken in modeling accurately all other characteristics of containments. (author). 9 refs., 9 figs

  3. Evaluation of radiation doses on critical organs in the treatment of cancer of the cervix using HDR-brachytherapy

    International Nuclear Information System (INIS)

    Soares, Taciana; Jansem, Teresa

    2000-01-01

    High dose-rate (HDR) brachytherapy is one type of treatment of the cervix carcinoma. During the planning for this therapy, especial attention is given to proximal normal organs such as bladder and rectum. In fact, due to their radiosensibility and localization, bladder and rectum are considered as critical organs. In this work we have studied the influence of the positioning of patient legs in the dose delivered to these critical organs in the treatment of cancer of the cervix using HDR-brachytherapy. (author)

  4. Use of CT or MR dosimetry in high dose rate (HDR) brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Liu, C.; Das, R.; See, A.; Duchesne, G.M.; Van Dyk, S.; Tai, K.H.

    2003-01-01

    Brachytherapy (BT) has, in recent years, become a well-utilised treatment option for prostate cancer. Tumour control probability relies on accurate dosimetry, which in turn relies on the accurate definition of the prostate gland. In external beam radiotherapy and BT, MRI has been shown to be a superior imaging modality when delineating the prostate gland especially at the apex. To date, data on MRI planning in prostate BT has focussed mainly on permanent interstitial implants. No data currently exists comparing MRI vs CT planning in HDR BT and its subsequent impact on prostate dosimetry. To determine the effects of MRI vs CT in HDR BT with respect to prostatic volumes and normal tissue doses, with the evaluations made using dose-volume histograms (DVH). Dosimetry parameters derived using CT and MRI (T2 weighted) scans of 11 patients who had received TRUS guided implants for HDR BT, were compared using the PlatoTM computer planning system. Treatment plans were generated on volumes marked by the same radiation oncologist for each patient. Comparison was made of the treatment plans (dosimetry) between: 1. CT generated plans; 2. CT generated plans assessed using MRI marked volumes and 3. MRI generated plans. We confirm the previously reported results that CT scans can overestimate prostatic volumes compared with MRI. Variations were noted in CT and MRI based plans that may allow improved sparing of the rectum and urethra when using MRI planning. The main disadvantages of using MRI scans are access to facilities as well as identifying a dummy source to adequately define the tips of our catheters. It is feasible to utilise MRI scans for HDR BT planning. The clearer definition of anatomical structures has added advantages when contouring the prostate

  5. A multicentre audit of HDR/PDR brachytherapy absolute dosimetry in association with the INTERLACE trial (NCT015662405)

    Science.gov (United States)

    Díez, P.; Aird, E. G. A.; Sander, T.; Gouldstone, C. A.; Sharpe, P. H. G.; Lee, C. D.; Lowe, G.; Thomas, R. A. S.; Simnor, T.; Bownes, P.; Bidmead, M.; Gandon, L.; Eaton, D.; Palmer, A. L.

    2017-12-01

    A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre’s treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60Co source, (Co0.A86). Alanine measurements when compared to the centres’ calculated dose showed a mean difference (±SD) of  +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.

  6. Consideration of the reservoir by the temperature history at the Hijiori HDR (hot dry rock) wells; Hijiori koon gantai no kokukosei ni okeru ondo rireki wo mochiita choryuso no kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, W; Shinohara, N; Osato, K; Takasugi, S [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1997-10-22

    Hot dry rock (HDR) power generation has been promoted by NEDO since 1984 at Hijiori, Okura village, Mogami-gun, Yamagata Prefecture. Hydraulic fracture tests and circulation tests have been conducted using four wells named as SKG-2, HDR-1, HDR-2 and HDR-3. Based on these test results, flow models of Hijiori shallow and deep reservoirs have been proposed. Conventional circulation tests have been analyzed only using temperature profile data. In this paper, circulation tests are analyzed by numerical simulation, to discuss individual characteristics of the shallow and deep reservoirs. Injection flow, production flow and circulation days were inputted as past circulation test data, to discuss the characteristics of geological layers, especially the permeability data, by which the features of temperature profiles in each well can be explained. As a result, it was found that the extension of permeable zone affecting the temperature in the SKG-2 well equivalent to the shallow reservoir was larger than that in the HDR-1 well. It was also found that there was a large difference in the permeability between the HDR-2a and HDR-3 wells. 5 refs., 8 figs., 2 tabs.

  7. On-line conformal HDR dose escalation trial in prostate cancer

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Stromberg, Jannifer; Edmundson, Gregory; Gustafson, Gary; Vicini, Frank; Brabbins, Donald

    1996-01-01

    Purpose: To improve treatment results on prostatic adenocarcinoma, we began the first prospective Phase I/II dose-escalating clinical trial of conformal brachytherapy (CB) and concurrent external beam irradiation. Methods and Materials: Fifty-four patients with T2b-T3c prostatic adenocarcinoma received 172 transperineal conformal high-dose rate (HDR) boost implants. All patients received concomitant external beam pelvic irradiation. Dose escalation of the three HDR fractions were: 5.5 Gy (18 patients), 6 Gy (15 patients), and 6.5 Gy (21 patients). The urethra, anterior rectal wall, and prostate boundaries were identified individually and outlined at 5 mm intervals from the base to the apex of the gland. The CB using real-time ultrasound guidance with interactive online isodose distributions was performed on an outpatient basis. As needles were placed into the prostate, corrections for prostate displacement were recorded and the isodose distributions were recalculated to represent the new relationship between the needles, prostate, and normal structures. Results: Craniocaudal motion of the gland ranged from 0.5-2.0 cm (mean=1.0 cm), whereas lateral displacement was 0.1-0.4 cm. With the interactive online planning system, organ motion was immediately detected, accounted for, and corrected prior to each HDR treatment. The rectal dose has ranged from 45 to 87%, and the urethral dose from 97 to 112% of the prostate dose. Negative prostatic biopsies at 18 months were seen in (30(32)) patients. Biochemical (PSA <1.5 ng/ml) control at 36 months is is 89%. It is significant that operator dependence has been completely removed because the interactive online planning system uniformly guides the physicians. Conclusions: With ultrasound guidance and the interactive online dosimetry system, organ motion is insignificant because it can be corrected during the procedure. Common pitfalls of brachytherapy, including operator dependence and difficulty with reproducibility, have been

  8. Acute genitourinary toxicity after high dose rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Second analysis to determine the correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Katoh, Hiroyuki; Noda, Shin-ei; Ito, Kazuto; Yamamoto, Takumi; Kashiwagi, Bunzo; Nakano, Takashi

    2005-01-01

    Purpose: We have been treating localized prostate cancer with high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiation therapy (EBRT) at our institution. We recently reported the existence of a correlation between the severity of acute genitourinary (GU) toxicity and the urethral radiation dose in HDR brachytherapy by using different fractionation schema. The purpose of this study was to evaluate the role of the urethral dose in the development of acute GU toxicity more closely than in previous studies. For this purpose, we conducted an analysis of patients who had undergone HDR brachytherapy with a fixed fractionation schema combined with hypofractionated EBRT. Methods and Materials: Among the patients with localized prostate cancer who were treated by 192-iridium HDR brachytherapy combined with hypofractionated EBRT at Gunma University Hospital between August 2000 and November 2004, we analyzed 67 patients who were treated by HDR brachytherapy with the fractionation schema of 9 Gy x two times combined with hypofractionated EBRT. Hypofractionated EBRT was administered at a fraction dose of 3 Gy three times weekly, and a total dose of 51 Gy was delivered to the prostate gland and seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography-guided HDR brachytherapy. The planning target volume was defined as the prostate gland with a 5-mm margin all around, and the planning was conducted based on computed tomography images. The tumor stage was T1c in 13 patients, T2 in 31 patients, and T3 in 23 patients. The Gleason score was 2-6 in 12 patients, 7 in 34 patients, and 8-10 in 21 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 11 months (range 3-24 months). The toxicities were graded based on the Radiation Therapy Oncology Group and the European Organization

  9. Implementation of microsource high dose rate (mHDR) brachytherapy in developing countries

    International Nuclear Information System (INIS)

    2001-11-01

    Brachytherapy using remote afterloading of a single high dose rate 192 Ir microsource was developed in the 1970s. After its introduction to clinics, this system has spread rapidly among developed Member States and has become a highly desirable modality in cancer treatment. This technique is now gradually being introduced to the developing Member States. The 192 Ir sources are produced with a high specific activity. This results in a high dose rate (HDR) to the tumour and shorter treatment times. The high specific activity simultaneously results in a much smaller source (so-called micro source, around I mm in diameter) which may be easily inserted into tissue through a thin delivery tube, the so-called interstitial treatment, as well as easily inserted into body cavities, the so-called intracavitary or endoluminal treatment. Another advantage is the ability to change dwell time (the time a source remains in one position) of the stepping source which allows dose distribution to match the target volume more closely. The purpose of this TECDOC is to advise radiation oncologists, medical physicists and hospital administrators in hospitals which are planning to introduce 192 Ir microsource HDR (mHDR) remote afterloading systems. The document supplements IAEA-TECDOC-1040, Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects, and will facilitate implementation of this new brachytherapy technology, especially in developing countries. The operation of the system, 'how to use the system', is not within the scope of this document. This TECDOC is based on the recommendations of an Advisory Group meeting held in Vienna in April 1999

  10. Fast exposure time decision in multi-exposure HDR imaging

    Science.gov (United States)

    Piao, Yongjie; Jin, Guang

    2012-10-01

    Currently available imaging and display system exists the problem of insufficient dynamic range, and the system cannot restore all the information for an high dynamic range (HDR) scene. The number of low dynamic range(LDR) image samples and fastness of exposure time decision impacts the real-time performance of the system dramatically. In order to realize a real-time HDR video acquisition system, this paper proposed a fast and robust method for exposure time selection in under and over exposure area which is based on system response function. The method utilized the monotony of the imaging system. According to this characteristic the exposure time is adjusted to an initial value to make the median value of the image equals to the middle value of the system output range; then adjust the exposure time to make the pixel value on two sides of histogram be the middle value of the system output range. Thus three low dynamic range images are acquired. Experiments show that the proposed method for adjusting the initial exposure time can converge in two iterations which is more fast and stable than average gray control method. As to the exposure time adjusting in under and over exposed area, the proposed method can use the dynamic range of the system more efficiently than fixed exposure time method.

  11. Essential results of analyses accompanying the leak rate experiments E22 at HDR

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1994-01-01

    Under the E22 test group of phase III of the HDR safety programme, experiments were performed on the crack opening and leak rate behaviour of pipe components of smaller nominal bores. The experiments were complemented by computations, in particular verifications, to qualify the computation models as one of the main aims of the HDR safety programme. Most of the analyses to determine crack openings were performed by means of the finite-element method, including elastic-plastic materials behaviour and, complementarily, assessing engineering methods. The leak rate was calculated by means of separate 2-phase computation models. Altogether, it may be concluded from the structural and fracture mechanical experiments with pipes, elbows and branch pieces, that crack openings and incipient cracks at loading with internal pressure or bending moment can be described with good accuracy by means of the finite-element programme ADINA and the developed FE-models. (orig.) [de

  12. Brachytherapy for Buccal Cancer: From Conventional Low Dose Rate (LDR) or Mold Technique to High Dose Rate Interstitial Brachytherapy (HDR-ISBT).

    Science.gov (United States)

    Kotsuma, Tadayuki; Yamazaki, Hideya; Masui, Koji; Yoshida, Ken; Shimizutani, Kimishige; Akiyama, Hironori; Murakami, Shumei; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko; Tanaka, Eiichi

    2017-12-01

    To examine the effectiveness of newly-installed high-dose-rate interstitial brachytherapy (HDR-ISBT) for buccal cancer. We retrospectively reviewed 36 patients (25 men and 11 women) with buccal cancer treated with curative brachytherapy with or without external radiotherapy with a median follow-up of 99 months. A total of 15 HDR-ISBT (median 48 Gy/ 8 fractions, range=24-60 Gy) patients were compared to conventional 15 cases LDR-ISBT (70 Gy, range=42.8-110 Gy) and 7 molds techniques (15 Gy, range=9-74 Gy). A total of 31 patients also underwent external radiotherapy (30 Gy, range=24-48 Gy). They comprised of 3T1, 23 T2, 8 T3, 3 T4 including 11 node positive cases. HDR-ISBT provided 82% of local control rate at 5 years, whereas conventional brachytherapy showed 72% [p=0.44; LDR-ISBT (65%), mold therapy (85.7%)]. Patients with early lesions (T1-2 or stage I-II) showed better local control rates than those with advanced lesions (T3-4 or stage III-IV). Severe late grade 3 complications developed in two patients treated with LDR-ISBT and EBRT. There is no significant difference in toxicity grade ≤2 between conventional brachytherapy (5/15=33%) and HDR-ISBT (7/32=32%, p=0.92). HDR-ISBT achieved good and comparable local control rates to conventional brachytherapy without elevating the toxicity. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. A study of optimization techniques in HDR brachytherapy for the prostate

    Science.gov (United States)

    Pokharel, Ghana Shyam

    Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

  14. Presumed atypical HDR syndrome associated with Band Keratopathy and pigmentary retinopathy.

    Science.gov (United States)

    Kim, Cinoo; Cheong, Hae Il; Kim, Jeong Hun; Yu, Young Suk; Kwon, Ji Won

    2011-01-01

    This report describes presumed atypical hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome associated with unexpected ocular findings. The patient had exotropia, bilateral band keratopathy, and pigmentary retinopathy, including attenuated retinal vessels and atrophy of the retinal pigment epithelium. Even though the calcific plaques were successfully removed, visual acuity in both eyes gradually decreased and electroretinography was extinguished. Copyright 2009, SLACK Incorporated.

  15. Comparing subjective and objective quality assessment of HDR images compressed with JPEG-XT

    DEFF Research Database (Denmark)

    Mantel, Claire; Ferchiu, Stefan Catalin; Forchhammer, Søren

    2014-01-01

    In this paper a subjective test in which participants evaluate the quality of JPEG-XT compressed HDR images is presented. Results show that for the selected test images and display, the subjective quality reached its saturation point starting around 3bpp. Objective evaluations are obtained...

  16. Comparison between Radiology Science Laboratory, Brazil (LCR) and National Research Council, Canada (NRC) of the absorbed dose in water using Fricke dosimetry

    International Nuclear Information System (INIS)

    Salata, Camila; David, Mariano Gazineu; Almeida, Carlos Eduardo de

    2014-01-01

    The absorbed dose to water standards for HDR brachytherapy dosimetry developed by the Radiology Science Laboratory, Brazil (LCR) and the National Research Council, Canada (NRC), were compared. The two institutions have developed absorbed dose standards based on the Fricke dosimetry system. There are significant differences between the two standards as far as the preparation and readout of the Fricke solution and irradiation geometry of the holder. Measurements were done at the NRC laboratory using a single Ir-192 source. The comparison of absorbed dose measurements was expressed as the ratio Dw(NRC)/Dw(LCR), which was found to be 1.026. (author)

  17. A rectum shield for the circular applicator system of a selectron unit (HDR and LDR afterloading)

    International Nuclear Information System (INIS)

    Hetzel, H.; McCoy, M.; Kamleitner, H.; Frommhold, H.

    1987-01-01

    In order to decrease the morbidity rate after combined radiotherapy of the cervix carcinoma, a tungsten shield 3 and 5 mm thick for the rectum has been developed by the authors which is applied with the ring and pin applicator of the selectron unit (LDR and HDR afterloading). The isodose curves were measured in a plexiglas phantom, and the radiation dose at the reference points was determined by means of a ionization dosemeter. The phantom measurements were performed with the same arrangement of sources as applied in radiotherapy. The measurements showed a dose reduction at point Rmax of 33% (HDR) and 44% (LDR) with the tungsten shield 5 mm thick. (orig.) [de

  18. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    International Nuclear Information System (INIS)

    Kolotas, C.; Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N.; Strassmann, G.; Aebersold, D.M.

    2003-01-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR 192 Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm 3 with a range of 41-2,103 cm 3 . Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  19. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland); Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Strassmann, G. [Dept. of Radiotherapy, Univ. Hospital, Philipps Univ., Marburg (Germany); Aebersold, D.M. [Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland)

    2003-07-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR {sup 192}Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm{sup 3} with a range of 41-2,103 cm{sup 3}. Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  20. Application of the Monte Carlo integration method in calculations of dose distributions in HDR-Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baltas, D; Geramani, K N; Ioannidis, G T; Kolotas, C; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany); Giannouli, S [Department of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece)

    1999-12-31

    Source anisotropy is a very important factor in brachytherapy quality assurance of high dose rate HDR Ir 192 afterloading stepping sources. If anisotropy is not taken into account then doses received by a brachytherapy patient in certain directions can be in error by a clinically significant amount. Experimental measurements of anisotropy are very labour intensive. We have shown that within acceptable limits of accuracy, Monte Carlo integration (MCI) of a modified Sievert integral (3D generalisation) can provide the necessary data within a much shorter time scale than can experiments. Hence MCI can be used for routine quality assurance schedules whenever a new design of HDR or PDR Ir 192 is used for brachytherapy afterloading. Our MCI calculation results are comparable with published experimental data and Monte Carlo simulation data for microSelectron and VariSource Ir 192 sources. We have shown not only that MCI offers advantages over alternative numerical integration methods, but also that treating filtration coefficients as radial distance-dependent functions improves Sievert integral accuracy at low energies. This paper also provides anisotropy data for three new Ir 192 sources, one for microSelectron-HDR and two for the microSelectron-PDR, for which data currently is not available. The information we have obtained in this study can be incorporated into clinical practice.

  1. Experimental work and know-how transfer in the framework of the individual project 'Earthquake investigations on the HDR reactor'

    International Nuclear Information System (INIS)

    Corvin, P.; Metz, K.

    1976-03-01

    In the framework of investigations to determine the earthquake resistance of nuclear power plant, carried out by the Applied Nucleonics Company on the HDR reactor in Grosswelzheim/Main, theoretical fundamentals and experimental test procedures in the sense of know-how transfer were elaborated. This enables the corresponding German institutions to carry out similar investigations on their own. In addition ANC carried out safety control measures during the investigations in order to prevent structural damage to the HDR reactor and neighbouring buildings. (orig.) 891 HP [de

  2. Essential results of analyses accompanying the leak rate experiments E22 at HDR

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1997-01-01

    During phase III of the HDR Safety Programme (HDR: decommissioned overheated steam reactor in Karlstein, Germany), experiments were performed in test group E22 on small-bore austenitic straight piping and on pipe elbows and branches containing through-wall cracks. The main aim was the determination of crack opening and leak rate behaviour for the cracked components under almost operational pressure and temperature loading conditions, especially including transient bending moments. In addition to machined slits, naturally grown fatigue cracks were also considered to cover the leakage behaviour. The experiments were accompanied by calculations, mainly performed by GRS. The paper describes the most important aspects and the essential results of the calculations and analysis. The main outcome was that the crack opening and initiation of crack growth can be described with the finite element techniques applied with sufficient accuracy. However, the qualification of the leak rate models could not be completed successfully, and therefore more sophisticated experiments of this kind are needed. (orig.)

  3. Salvage prostate HDR brachytherapy combined with interstitial hyperthermia for local recurrence after radiation therapy failure

    Energy Technology Data Exchange (ETDEWEB)

    Kukielka, A.M.; Hetnal, M.; Dabrowski, T.; Walasek, T.; Brandys, P.; Reinfuss, M. [Centre of Oncology, M. Sklodowska - Curie Institute, Krakow Branch, Department of Radiotherapy, Krakow (Poland); Nahajowski, D.; Kudzia, R.; Dybek, D. [Centre of Oncology, M. Sklodowska - Curie Institute, Krakow Branch, Department of Medical Physics, Department of Radiotherapy, Krakow (Poland)

    2014-02-15

    The aim of the present retrospective study is to evaluate toxicity and early clinical outcomes of interstitial hyperthermia (IHT) combined with high-dose rate (HDR) brachytherapy as a salvage treatment in patients with biopsy-confirmed local recurrence of prostate cancer after previous external beam radiotherapy. Between September 2008 and March 2013, 25 patients with local recurrence of previously irradiated prostate cancer were treated. The main eligibility criteria for salvage prostate HDR brachytherapy combined with interstitial hyperthermia were biopsy confirmed local recurrence and absence of nodal and distant metastases. All patients were treated with a dose of 30 Gy in 3 fractions at 21-day intervals. We performed 62 hyperthermia procedures out of 75 planned (83 %). The aim of the hyperthermia treatment was to heat the prostate to 41-43 C for 60 min. Toxicity for the organs of the genitourinary system and rectum was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE, v. 4.03). Determination of subsequent biochemical failure was based on the Phoenix definition (nadir + 2 ng/ml). The median age was 71 years (range 62-83 years), the median initial PSA level was 16.3 ng/ml (range 6.37-64 ng/ml), and the median salvage PSA level was 2.8 ng/ml (1.044-25.346 ng/ml). The median follow-up was 13 months (range 4-48 months). The combination of HDR brachytherapy and IHT was well tolerated. The most frequent complications were nocturia, weak urine stream, urinary frequency, hematuria, and urgency. Grade 2 rectal hemorrhage was observed in 1 patient. No grade 3 or higher complications were observed. The 2-year Kaplan-Meier estimate of biochemical control after salvage treatment was 74 %. The PSA in 20 patients decreased below the presalvage level, while 11 patients achieved a PSA nadir < 0.5 ng/ml. All patients are still alive. Of the 7 patients who experienced biochemical failure, bone metastases were found in 2 patients. IHT in combination

  4. Comparison of air-kerma strength determinations for HDR 192Ir sources

    International Nuclear Information System (INIS)

    Rasmussen, Brian E.; Davis, Stephen D.; Schmidt, Cal R.; Micka, John A.; DeWerd, Larry A.

    2011-01-01

    Purpose: To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) 192 Ir brachytherapy sources maintained by University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. Methods: The improved, laser-aligned seven-distance apparatus of University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR 192 Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the 192 Ir air-kerma calibration coefficient from the NIST air-kerma standards at 137 Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A wall for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. Results: The average measurements when using the inverse N K interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Conclusions: Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well chambers was 0.01%, confirming that

  5. Comparison of air-kerma strength determinations for HDR (192)Ir sources.

    Science.gov (United States)

    Rasmussen, Brian E; Davis, Stephen D; Schmidt, Cal R; Micka, John A; Dewerd, Larry A

    2011-12-01

    To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) (192)Ir brachytherapy sources maintained by the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. The improved, laser-aligned seven-distance apparatus of the University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR (192)Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the (192)Ir air-kerma calibration coefficient from the NIST air-kerma standards at (137)Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A(wall) for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. The average measurements when using the inverse N(K) interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well chambers was 0.01%, confirming that it is not necessary to

  6. Seismic investigations of the HDR Safety Program. Summary report

    International Nuclear Information System (INIS)

    Malcher, L.; Schrammel, D.; Steinhilber, H.; Kot, C.A.

    1994-08-01

    The primary objective of the seismic investigations, performed at the HDR facility in Kahl/Main, FRG was to validate calculational methods for the seismic evaluation of nuclear-reactor systems, using experimental data from an actual nuclear plant. Using eccentric mass shaker excitation the HDR soil/structure system was tested to incipient failure, exhibiting highly nonlinear response and demonstrating that structures not seismically designed can sustain loads equivalent to a design basin earthquake (DBE). Load transmission from the structure to piping/equipment indicated significant response amplifications and shifts to higher frequencies, while the response of tanks/vessels depended mainly on their support conditions. The evaluation of various piping support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is important to limiting pipe greens. Piping at loads exceeding the DBE eightfold still had significant margins and failure is improbable inspite of multiple support failures. The mean value for pipe damping, even under extreme loads, was found to be about 4%. Comparison of linear and nonlinear computational results with piping response measurements showed that predictions have a wide scatter and do not necessarily yield conservative responses underpredicting, in particular, peak support forces. For the soil/structure system the quality of the predictions did not depend so much on the complexity of the modeling, but rather on whether the model captured the salient features and nonlinearities of the system

  7. Radiological sciences in Turkey: its past, present and future

    International Nuclear Information System (INIS)

    Ozyar, E.

    2002-01-01

    After the discovery of X-rays in 1895, first X-rays was produced with an X-ray tube one year after in Istanbul and used with diagnostic and therapeutic aims thereafter. Parallel to the technological advances in radiology, radiation oncology and nuclear medicine, all kind of modern tools became available in Turkish Republic. There are two oncology institutes affiliated with major universities in Turkey currently. These institutions are located in Ankara and Istanbul and aimed for the research, education, and the application of the newest technology for the diagnosis and treatment in the field of basic and clinical oncology as well as in cancer epidemiology and prevention. Beside these comprehensive cancer centers there were more than 50 university hospitals with radiology, nuclear medicine and radiation oncology facilities in Turkey. Diagnostic and interventional radiology was widely available in university and governmental hospitals. Currently conventional X-ray techniques, ultrasonography, mammography, computed tomography, magnetic resonance imaging, was available in most of the cities. Interventional procedures are performed in most of the centers. There are more than 20 university hospitals equipped with Cobalt-60 units, linear accelerators, LDR, MDR, HDR brachytherapy, stereotactic radiosurgery, gamma knife, computerized treatment planning systems. All these departments have all facilities for precise in-vivo and in-vitro measurements mandatory for precise radiotherapy. Two comprehensive cancer centers have post graduate programs of radiation physics and treatment planning. The field of .nuclear medicine is rapidly growing in Turkey. Routine diagnostic services are given in almost every city. These diagnostic studies frequently performed include bone, renal, thyroid, lung and myocardial Perfusion, whole body Gallium scans, and other scintigraphic images such as gastrointestinal bleeding, gastroesophageal reflux, I-131-MIBG studies etc. Treatment is also

  8. Determination of the dose of traffic in HDR brachytherapy with ALANINE/R PE technique

    International Nuclear Information System (INIS)

    Guzman Calcina, C. S.; Chen, F.; Almeida, A. de; Baffa, O.

    2001-01-01

    It determines, experimentally, the dose of traffic in brachytherapy for High Dose Rate (HDR), using for the first-time the Electronic Paramagnetic Resonance (EPR) technique with alanine detectors. The value obtained is the published next to obtained using lithium fluoride thermoluminescent dosimeters [es

  9. HDR Pathological Image Enhancement Based on Improved Bias Field Correction and Guided Image Filter

    Directory of Open Access Journals (Sweden)

    Qingjiao Sun

    2016-01-01

    Full Text Available Pathological image enhancement is a significant topic in the field of pathological image processing. This paper proposes a high dynamic range (HDR pathological image enhancement method based on improved bias field correction and guided image filter (GIF. Firstly, a preprocessing including stain normalization and wavelet denoising is performed for Haematoxylin and Eosin (H and E stained pathological image. Then, an improved bias field correction model is developed to enhance the influence of light for high-frequency part in image and correct the intensity inhomogeneity and detail discontinuity of image. Next, HDR pathological image is generated based on least square method using low dynamic range (LDR image, H and E channel images. Finally, the fine enhanced image is acquired after the detail enhancement process. Experiments with 140 pathological images demonstrate the performance advantages of our proposed method as compared with related work.

  10. Effect and toxicity of endoluminal high-dose-rate (HDR) brachytherapy in centrally located tumors of the upper respiratory tract

    International Nuclear Information System (INIS)

    Harms, W.; Wannenmacher, M.; Becker, H.; Herth, F.; Fritz, P.

    2000-01-01

    Aim: To assess effect an toxicity of high-dose-rate afterloading (HDR) alone or in combination with external beam radiotherapy (EBRT) in centrally located tumors of the upper respiratory tract. Patients and Methods: From 1987 to 1996, 55 patients were treated. Twenty-one patients (group A1: 17 non-small-cell lung cancer [NSCLC], A2: 4 metastases from other malignancies) were treated using HDR alone due to a relapse after external beam irradiation. In 34 previously untreated and inoperable patients (group B1: 27 NSCLC, B2: 7 metastases from other malignancies) HDR was given as a boost after EBRT (30 to 60 Gy, median 50). HDR was carried out with a 192 Ir source (370 GBq). The brachytherapy dose (group A: 5 to 27 Gy, median 20; B: 10 to 20 Gy, median 15) was prescribed to 1 cm distance from the source axis. A distanciable applicator was used in 39/55 patients. Results: In group A1, a response rate (CR, PR) of 53% (group B1: 77%) was reached. The median survival (Kaplan-Meier) was 5 months in group A1 (B1: 20 months). The 1-, 3- and 5-year local progression free survival rates (Kaplan-Meier) were 66% (15%), 52% (0%), and 37% (0%) in group B1 (group A1). Prognostic favorable factors in group B1 were a tumor diameter 70. Grade-1 or 2 toxicity (RTOG/EORTC) occurred in 0% in group A and in 6% in group B. We observed no Grad-3 or 4 toxicity. Complications caused by persistent or progressive local disease occurred in 3 patients in goup A (fatal hemorrhage, tracheomediastinal fistula, hemoptysis) and in 2 patients in group B (fatal hemorrhage, hemoptysis). Conclusions: HDR brachytherapy is an effective treatment with moderate side effects. In combination with external beam irradiation long-term remissions can be reached in one third of the patients. (orig.) [de

  11. Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

    International Nuclear Information System (INIS)

    Whitaker, May; Hruby, George; Lovett, Aimee; Patanjali, Nitya

    2011-01-01

    Background and purpose: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methods: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5 mm or more, indexer positions were adjusted prior to treatment delivery. Results: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81–367 min). Median catheter displacement was 7.5 mm (range −2.9–23.9 mm), 67% of implants had displacement of 5 mm or greater. Displacements were predominantly caudal. Conclusions: Catheter displacement can occur in the 1–3 h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

  12. SU-F-T-28: Evaluation of BEBIG HDR Co-60 After-Loading System for Skin Cancer Treatment Using Conical Surface Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, H; Soliman, A; Song, W Y [Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Meigooni, A S [Department of Radiation Therapy, Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States); Han, D [Departemt of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States)

    2016-06-15

    Purpose: To evaluate the possibility of utilizing the BEBIG HDR 60Co remote after-loading system for malignant skin surface treatment using Monte Carlo (MC) simulation technique. Methods: First TG-43 parameters of BEBIG-Co-60 and Nucletron Ir-192-mHDR-V2 brachytherapy sources were simulated using MCNP6 code to benchmark the sources against the literature. Second a conical tungsten-alloy with 3-cm diameter of Planning-Target-Volume (PTV) at surface for use with a single stepping HDR source is designed. The HDR source is modeled parallel to treatment plane at the center of the conical applicator with a source surface distance (SSD) of 1.5-cm and a removable plastic end-cap with a 1-mm thickness. Third, MC calculated dose distributions from HDR Co-60 for conical surface applicator were compared with the simulated data using HDR Ir-192 source. The initial calculations were made with the same conical surface applicator (standard-applicator) dimensions as the ones used with the Ir-192 system. Fourth, the applicator wall-thickness for the Co-60 system was increased (doubled) to diminish leakage dose to levels received when using the Ir-192 system. With this geometry, percentage depth dose (PDD), and relative 2D-dose profiles in transverse/coronal planes were normalized at 3-mm prescription-depth evaluated along the central axis. Results: PDD for Ir-192 and Co-60 were similar with standard and thick-walled applicator. 2D-relative dose distribution of Co-60, inside the standard-conical-applicator, generated higher penumbra (7.6%). For thick-walled applicator, it created smaller penumbra (<4%) compared to Ir-192 source in the standard-conicalapplicator. Dose leakage outside of thick-walled applicator with Co-60 source was approximately equal (≤3%) with standard applicator using Ir-192 source. Conclusion: Skin cancer treatment with equal quality can be performed with Co-60 source and thick-walled conical applicators instead of Ir-192 with standard applicators. These conical

  13. HDR and LDR Brachytherapy in the Treatment of Lip Cancer: the Experience of the Catalan Institute of Oncology.

    Science.gov (United States)

    Ayerra, Arrate Querejeta; Mena, Estefanía Palacios; Fabregas, Joan Pera; Miguelez, Cristina Gutiérrez; Guedea, Ferran

    2010-03-01

    Lip cancer can be treated by surgery, external radiotherapy, and/or brachytherapy (BT). In recent years, BT has become increasingly favored for this type of cancer. The aim of the present study was to analyze local control and survival of patients treated at our institution between July 1989 and June 2008. We performed a retrospective study of 121 patients (109 males and 12 females) who underwent lip cancer brachytherapy from July 1989 to June 2008. Median age was 67 years and median follow-up was 31.8 months (range 20-188 months). Out of 121 patients, 100 (82.6%) were treated with low dose rate (LDR) BT while the remaining 21 patients (17.4%) received high dose rate (HDR) BT. The most common cell type was squamous cell carcinoma (115 cases; 95%) and most tumors were located on the lower lip (107 patients; 88.4%). Most cases were either stage T1 (62 patients; 51.2%), or T2 (44 cases; 36.4%). After 15 years of follow-up, overall survival was 89.5%, cause-specific survival 97.8%, and disease-free survival 86.6%. Local, regional, and distant control at 15 years were 90%, 92%, and 98.8%, respectively. Grade 3 mucosal toxicity was observed in 23% of patients treated with LDR compared to 33% of HDR patients, and grade 4 mucosal toxicity in 9% versus 0% in the HDR group. Our findings confirm that brachytherapy is an effective treatment for lip cancer. The results from our series are in line with those published elsewhere. Based on our limited data, HDR appears to be equally as good as LDR, although this needs to be confirmed by further studies.

  14. Verification of experimental modal modeling using HDR (Heissdampfreaktor) dynamic test data

    International Nuclear Information System (INIS)

    Srinivasan, M.G.; Kot, C.A.; Hsieh, B.J.

    1983-01-01

    Experimental modal modeling involves the determination of the modal parameters of the model of a structure from recorded input-output data from dynamic tests. Though commercial modal analysis algorithms are being widely used in many industries their ability to identify a set of reliable modal parameters of an as-built nuclear power plant structure has not been systematically verified. This paper describes the effort to verify MODAL-PLUS, a widely used modal analysis code, using recorded data from the dynamic tests performed on the reactor building of the Heissdampfreaktor, situated near Frankfurt, Federal Republic of Germany. In the series of dynamic tests on HDR in 1979, the reactor building was subjected to forced vibrations from different types and levels of dynamic excitations. Two sets of HDR containment building input-output data were chosen for MODAL-PLUS analyses. To reduce the influence of nonlinear behavior on the results, these sets were chosen so that the levels of excitation are relatively low and about the same in the two sets. The attempted verification was only partially successful in that only one modal model, with a limited range of validity, could be synthesized and in that the goodness of fit could be verified only in this limited range

  15. Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

    International Nuclear Information System (INIS)

    Wang Zhou; Jaggernauth, Wainwright; Malhotra, Harish K.; Podgorsak, Matthew B.

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  16. Neodadjuvante und adjuvante Kurzzeit-Hormontherapie in Kombination mit konformaler HDR-Brachytherapie beim Prostatakarzinom

    Directory of Open Access Journals (Sweden)

    Martin T

    2004-01-01

    Full Text Available Zielsetzung: Auswertung der Behandlungsergebnisse der neoadjuvanten und adjuvanten Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie beim Prostatakarzinom. Patienten und Methoden: Von 01/97 bis 09/99 behandelten wir 102 Patienten mit Prostatakarzinomen im Stadium T1–3 N0 M0. Im Stadium T1–2 befanden sich 71, im Stadium T3 31 Patienten. Der mediane prätherapeutische PSA-Wert betrug 15,3 ng/ml. Nach ultraschallgesteuerter transrektaler Implantation von vier Afterloadingnadeln erfolgte die CT-gestützte 3D-Brachytherapie- Planung. Alle Patienten erhielten vier HDR-Implantate mit einer Referenzdosis von 5 Gy oder 7 Gy pro Implantat. Die Zeit zwischen jedem Implantat betrug jeweils 14 Tage. Nach der Brachytherapie folgte die externe Radiotherapie bis 39,6 Gy oder 45,0 Gy. Alle Patienten erhielten eine neoadjuvante und adjuvante Kurzzeit-Hormontherapie, die 2–19 Monate vor der Brachytherapie eingeleitet und 3 Monate nach Abschluß der externen Radiotherapie abgesetzt wurde (mediane Dauer: 9 Monate. Ergebnisse: Die mediane Nachbeobachtungszeit war 2,6 Jahre (range: 2,0–4,1 Jahre. Die biochemische Kontrollrate betrug 82 % nach 3 Jahren. Bei 14/102 Patienten registrierten wir ein biochemisches Rezidiv, bei 5/102 Patienten ein klinisches Rezidiv. Das Gesamtüberleben betrug 90 %, das krankheitsspezifische Überleben 98,0 % nach 3 Jahren. Ein Patient entwickelte eine prostato-urethro-rektale Fistel als späte Grad 4-Toxizität. Akute Grad-3 Toxizitäten traten bei 4 %, späte Grad-3 Toxizitäten bei 5 % der Patienten auf. Schlußfolgerung: Die neoadjuvante und adjuvante Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie erweist sich als sichere und wirksame Behandlungsmodalität beim Prostatakarzinom mit minimalen behandlungsbedingten Toxizitäten und einer vielversprechenden biochemischen Kontrollrate nach medianer Nachbeobachtungszeit von 2,6 Jahren.

  17. SU-E-T-380: Evaluation of BEBIG HDR 60Co System for AccuBoost Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zehtabian, M; Sina, S [Shiraz University, Shiraz, Fars (Iran, Islamic Republic of); Rivard, M [Tufts University School of Medicine, Boston, MA (United States); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: In this project, the possibility of utilizing the BEBIG 60Co HDR system for AccuBoostTM treatment has been evaluated. Methods: Dose distributions in various breast sizes have been calculated for both Co-60 and Ir-192 sources using the MCNP5 code. These calculations were performed in breast tissues with thicknesses of 4cm, 6cm, and 8cm. The initial calculations were performed with the same applicator dimensions as the existing applicators used with the HDR Ir-192 system. The activity of the Co-60 source was selected such that the dose at the breast center was the same as the values from 192Ir. Then, the applicator thicknesses were increased to twice of those used with HDR Ir-192 system, for reducing skin and chest doses by Co-60 system. Dose to breast skin and chest wall were compared for both applicators types, with and without inclusion of a focusing cone at the applicator center. Results: The results showed that loading HDR Co-60 source inside the thin applicators impose higher doses to breast skin and chest wall compared to the 192Ir source. The area of the chest wall covered by 10Gy when treated by Co-60 with the thin and thick applicators, or treated by Ir-192 with thin applicator are 79cm2, 39cm2, and 3.8cm2, respectively. These values are reduced to 34cm2, 0cm2, and 0cm2 by using the focusing cone. It is worth noting that the breast skin areas covered by the 60Gy isodose line are 9.9cm2 and 7.8cm2 for Co-60 with the thin and thick applicators, respectively, while it is 20cm2 for Ir-192 when no focusing cone is present. These values are 0cm2, 0cm2, and 11cm2 in the presence of the focusing cone. Conclusion: The results indicate that using Co-60 with the thicker applicators is beneficial because of the higher half-life of Co-60, and the reduced maximum skin dose when compared with Ir-192.

  18. Comparison of air-kerma strength determinations for HDR {sup 192}Ir sources

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Brian E.; Davis, Stephen D.; Schmidt, Cal R.; Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2011-12-15

    Purpose: To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) {sup 192}Ir brachytherapy sources maintained by University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. Methods: The improved, laser-aligned seven-distance apparatus of University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR {sup 192}Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the {sup 192}Ir air-kerma calibration coefficient from the NIST air-kerma standards at {sup 137}Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A{sub wall} for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. Results: The average measurements when using the inverse N{sub K} interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Conclusions: Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well

  19. Commissioning and clinical implementation of HDR brachytherapy in El Salvador

    International Nuclear Information System (INIS)

    Morales Lopez, Jorge Luis; Castillo, Luis Frank; Castillo Bahi, Ramon del

    2009-01-01

    The Gynecologic Cancer is one of the best known malignancies in different countries of the world, with a high incidence in developing countries. In the treatment of this disease have been used multiple treatment arms among which is the high rate brachytherapy (HDR). The IAEA has put much emphasis on supporting all programs to treat this disease and in this context within the project 'Human Resource Development and Nuclear Technology Support', collaborated with the dispatch of experts on mission ELS0006 01 'Assistance to the ICES in HDR brachytherapy initiating Treatments at the Cancer Institute of El Salvador 'Dr. Narciso Diaz Bazan' in San Salvador, El Salvador. The process of commissioning and implementing clinical service Brachytherapy High Dose Rate (HDR BT) is a relatively complex process that begins with the formation of functional and technical service, based on flow patients to be treated, availability of local technological capability to install, and culminates with the preparation and implementation of protocols. Experts involved in the implementation of this service divided this task in stages organized chronologically: 1st. Study of existing infrastructure and level of training of technical personnel available, 2nd. Proposal and application of amendments in order to adapt the facility to the planned patient flow and optimal use of technological infrastructure, 3rd. Establishment of the process of securing the disposable waste materials and not required, 4th. Performance of tests of physical commissioning clinical dosimetry and instrumentation unit, surgical and therapeutic, 5th. Training of technical personnel, 6th. Preparation of clinical protocol and 7th. Initiation and development of treatment for patients. All these steps are carried out with the integration and consensus of the entire multidisciplinary team that makes up the service and with the support of the administration as a prerequisite. Within two weeks the service was modified according to

  20. Source position verification and dosimetry in HDR brachytherapy using an EPID

    International Nuclear Information System (INIS)

    Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

    2013-01-01

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192 Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192 Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

  1. SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    International Nuclear Information System (INIS)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

    2016-01-01

    Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

  2. SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

  3. Mixed integer programming improves comprehensibility and plan quality in inverse optimization of prostate HDR Brachytherapy

    NARCIS (Netherlands)

    Gorissen, B.L.; den Hertog, D.; Hoffmann, A.L.

    2013-01-01

    Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or

  4. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1991-12-15

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient.

  5. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    International Nuclear Information System (INIS)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck

    1991-01-01

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient

  6. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  7. SU-F-T-63: Dosimetric Relevance of the Valencia and Leipzig HDR Applicators Plastic Cap

    Energy Technology Data Exchange (ETDEWEB)

    Granero, D [ERESA-Hospital General Universitario, Valencia (Spain); Candela-Juan, C [National Dosimetry Centre (CND), Valencia (Spain); Vijande, J; Ballester, F [University of Valencia, Burjassot (Spain); Perez-Calatayud, J [Hospital La Fe, Valencia (Spain); Jacob, D; Mourtada, F [Helen F. Graham Cancer Center, Christiana Care Health System, Newark, DE (United States)

    2016-06-15

    Purpose: Utilization of HDR brachytherapy treatment of skin lesions using collimated applicators, such as the Valencia or Leipzig is increasing. These applicators are made of cup-shaped tungsten material in order to focalize the radiation into the lesion and to protect nearby tissues. These applicators have an attachable plastic cap that removes secondary electrons generated in the applicator and flattens the treatment surface. The purpose of this study is to examine the dosimetric impact of this cap, and the effect if the cap is not placed during the HDR fraction delivery. Methods: Monte Carlo simulations have been done using the code Geant4 for the Valencia and Leipzig applicators. Dose rate distributions have been obtained for the applicators with and without the plastic cap. An experimental study using EBT3 radiochromic film has been realized in order to verify the Monte Carlo results. Results: The Monte Carlo simulations show that absorbed dose in the first millimeter of skin can increase up to 180% for the Valencia applicator if the plastic cap is absent and up to 1500% for the Leipzig applicators. At deeper distances the increase of dose is smaller being about 10–15%. Conclusion: Important differences have been found if the plastic cap of the applicators is absent in the treatment producing an overdosage in the skin. The user should have a checklist to remind him check always before HDR fraction delivery to insure the plastic cap is placed on the applicator. This work was supported in part by Generalitat Valenciana under Project PROMETEOII/2013/010, by the Spanish Government under Project No. FIS2013-42156, and by a research agreement with Elekta Brachytherapy, Veenendaal, The Netherlands.

  8. WE-DE-201-02: A Statistical Analysis Tool for Plan Quality Verification in HDR Brachytherapy Forward Planning for Cervix Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, R; Zhu, X; Li, S; Zheng, D; Lei, Y; Wang, S; Verma, V; Bennion, N; Wahl, A; Zhou, S [University of Nebraska Medical Center, Omaha, NE (United States)

    2016-06-15

    Purpose: High Dose Rate (HDR) brachytherapy forward planning is principally an iterative process; hence, plan quality is affected by planners’ experiences and limited planning time. Thus, this may lead to sporadic errors and inconsistencies in planning. A statistical tool based on previous approved clinical treatment plans would help to maintain the consistency of planning quality and improve the efficiency of second checking. Methods: An independent dose calculation tool was developed from commercial software. Thirty-three previously approved cervical HDR plans with the same prescription dose (550cGy), applicator type, and treatment protocol were examined, and ICRU defined reference point doses (bladder, vaginal mucosa, rectum, and points A/B) along with dwell times were collected. Dose calculation tool then calculated appropriate range with a 95% confidence interval for each parameter obtained, which would be used as the benchmark for evaluation of those parameters in future HDR treatment plans. Model quality was verified using five randomly selected approved plans from the same dataset. Results: Dose variations appears to be larger at the reference point of bladder and mucosa as compared with rectum. Most reference point doses from verification plans fell between the predicted range, except the doses of two points of rectum and two points of reference position A (owing to rectal anatomical variations & clinical adjustment in prescription points, respectively). Similar results were obtained for tandem and ring dwell times despite relatively larger uncertainties. Conclusion: This statistical tool provides an insight into clinically acceptable range of cervical HDR plans, which could be useful in plan checking and identifying potential planning errors, thus improving the consistency of plan quality.

  9. SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kalavagunta, C; Lasio, G; Yi, B; Zhou, J; Lin, M [Univ. of Maryland School Of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquired for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.

  10. TU-F-BRF-02: MR-US Prostate Registration Using Patient-Specific Tissue Elasticity Property Prior for MR-Targeted, TRUS-Guided HDR Brachytherapy

    International Nuclear Information System (INIS)

    Yang, X; Rossi, P; Ogunleye, T; Jani, A; Curran, W; Liu, T

    2014-01-01

    Purpose: High-dose-rate (HDR) brachytherapy has become a popular treatment modality for prostate cancer. Conventional transrectal ultrasound (TRUS)-guided prostate HDR brachytherapy could benefit significantly from MR-targeted, TRUS-guided procedure where the tumor locations, acquired from the multiparametric MRI, are incorporated into the treatment planning. In order to enable this integration, we have developed a MR-TRUS registration with a patient-specific biomechanical elasticity prior. Methods: The proposed method used a biomechanical elasticity prior to guide the prostate volumetric B-spline deformation in the MRI and TRUS registration. The patient-specific biomechanical elasticity prior was generated using ultrasound elastography, where two 3D TRUS prostate images were acquired under different probe-induced pressures during the HDR procedure, which takes 2-4 minutes. These two 3D TRUS images were used to calculate the local displacement (elasticity map) of two prostate volumes. The B-spline transformation was calculated by minimizing the Euclidean distance between the normalized attribute vectors of the prostate surface landmarks on the MR and TRUS. This technique was evaluated through two studies: a prostate-phantom study and a pilot study with 5 patients undergoing prostate HDR treatment. The accuracy of our approach was assessed through the locations of several landmarks in the post-registration and TRUS images; our registration results were compared with the surface-based method. Results: For the phantom study, the mean landmark displacement of the proposed method was 1.29±0.11 mm. For the 5 patients, the mean landmark displacement of the surface-based method was 3.25±0.51 mm; our method, 1.71±0.25 mm. Therefore, our proposed method of prostate registration outperformed the surfaced-based registration significantly. Conclusion: We have developed a novel MR-TRUS prostate registration approach based on patient-specific biomechanical elasticity prior

  11. Implementation of the technique of partial irradiation accelerated the breast with high doses (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Molina Lopez, M. Y.; Pardo Perez, E.; Castro Novais, J.; Martinez Ortega, J.; Ruiz Maqueda, S.; Cerro Penalver, E. del

    2013-01-01

    The objective of this work is presents procedure carried out in our Centre for the implementation of the accelerated partial breast irradiation (APBI, accelerated partial-breast irradiation) with high-rate brachytherapy (HDR), using plastic tubes as applicators. Carried out measures, the evaluation of the dosimetric parameters analyzing and presenting the results. (Author)

  12. SU-E-T-785: Using Systems Engineering to Design HDR Skin Treatment Operation for Small Lesions to Enhance Patient Safety

    International Nuclear Information System (INIS)

    Saw, C; Baikadi, M; Peters, C; Brereton, H

    2015-01-01

    Purpose: Using systems engineering to design HDR skin treatment operation for small lesions using shielded applicators to enhance patient safety. Methods: Systems engineering is an interdisciplinary field that offers formal methodologies to study, design, implement, and manage complex engineering systems as a whole over their life-cycles. The methodologies deal with human work-processes, coordination of different team, optimization, and risk management. The V-model of systems engineering emphasize two streams, the specification and the testing streams. The specification stream consists of user requirements, functional requirements, and design specifications while the testing on installation, operational, and performance specifications. In implementing system engineering to this project, the user and functional requirements are (a) HDR unit parameters be downloaded from the treatment planning system, (b) dwell times and positions be generated by treatment planning system, (c) source decay be computer calculated, (d) a double-check system of treatment parameters to comply with the NRC regulation. These requirements are intended to reduce human intervention to improve patient safety. Results: A formal investigation indicated that the user requirements can be satisfied. The treatment operation consists of using the treatment planning system to generate a pseudo plan that is adjusted for different shielded applicators to compute the dwell times. The dwell positions, channel numbers, and the dwell times are verified by the medical physicist and downloaded into the HDR unit. The decayed source strength is transferred to a spreadsheet that computes the dwell times based on the type of applicators and prescribed dose used. Prior to treatment, the source strength, dwell times, dwell positions, and channel numbers are double-checked by the radiation oncologist. No dosimetric parameters are manually calculated. Conclusion: Systems engineering provides methodologies to

  13. Seismic tests at the HDR facility using explosives and solid propellant rockets

    International Nuclear Information System (INIS)

    Corvin, P.; Steinhilber, H.

    1981-01-01

    In blast tests the HDR reactor building and its mechanical equipment were subjected to earthquake-type excitations through the soil and the foundation. A series of six tests was carried out, two tests being made with HDR facility under operating conditions (BWR conditions, 285 0 C, 70 bar). The charges were placed in boreholes at a depth of 4 to 10 m and a distance of 16 to 25 m from the reactor building. The tests with solid propellant rockets were made in order to try a new excitation technique. The rockets used in these tests were of compact design and had a short combustion period (500 ms) at high constant thrust (100 kN per combustion chamber). These rockets were fixed to the concrete dome of the building in such a way that the thrust generated during the combustion of the propellant resulted in an impulsive load acting on the building. This type of excitation was selected with a view to investigating the global effects of the load case 'aircraft impact' on the building and the mechanical equipment. In the four tests made so far, up to four rockets were ignited simultaneously, so that the maximum impulse was 2 x 10 5 Ns. The excitation level can be markedly increased by adding further rockets. This excitation technique was characterised by excellent reproducibility of the load parameters. (orig./HP)

  14. SU-E-T-149: Brachytherapy Patient Specific Quality Assurance for a HDR Vaginal Cylinder Case

    Energy Technology Data Exchange (ETDEWEB)

    Barbiere, J; Napoli, J; Ndlovu, A [Hackensack Univ Medical Center, Hackensack, NJ (United States)

    2015-06-15

    Purpose: Commonly Ir-192 HDR treatment planning system commissioning is only based on a single absolute measurement of source activity supplemented by tabulated parameters for multiple factors without independent verification that the planned distribution corresponds to the actual delivered dose. The purpose on this work is to present a methodology using Gafchromic film with a statistically valid calibration curve that can be used to validate clinical HDR vaginal cylinder cases by comparing the calculated plan dose distribution in a plane with the corresponding measured planar dose. Methods: A vaginal cylinder plan was created with Oncentra treatment planning system. The 3D dose matrix was exported to a Varian Eclipse work station for convenient extraction of a 2D coronal dose plane corresponding to the film position. The plan was delivered with a sheet of Gafchromic EBT3 film positioned 1mm from the catheter using an Ir-192 Nucletron HDR source. The film was then digitized with an Epson 10000 XL color scanner. Film analysis is performed with MatLab imaging toolbox. A density to dose calibration curve was created using TG43 formalism for a single dwell position exposure at over 100 points for statistical accuracy. The plan and measured film dose planes were registered using a known dwell position relative to four film marks. The plan delivered 500 cGy to points 2 cm from the sources. Results: The distance to agreement of the 500 cGy isodose between the plan and film measurement laterally was 0.5 mm but can be as much as 1.5 mm superior and inferior. The difference between the computed plan dose and film measurement was calculated per pixel. The greatest errors up to 50 cGy are near the apex. Conclusion: The methodology presented will be useful to implement more comprehensive quality assurance to verify patient-specific dose distributions.

  15. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    International Nuclear Information System (INIS)

    Craciunescu, O; Todor, D; Leeuw, A de

    2014-01-01

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy

  16. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, O [Duke University Medical Center, Durham, NC (United States); Todor, D [Virginia Commonwealth University, Richmond, VA (United States); Leeuw, A de

    2014-06-15

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy.

  17. Educational treasures in Radiology: The Radiology Olympics - striving for gold in Radiology education

    OpenAIRE

    Talanow, Roland

    2010-01-01

    This article focuses on Radiology Olympics (www.RadiologyOlympics.com) - a collaboration with the international Radiology community for Radiology education, Radiolopolis (www.Radiolopolis.com). The Radiology Olympics honour the movers and shakers in Radiology education and offer an easy to use platform for educating medical professionals based on Radiology cases.

  18. A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Palmer, Antony L.; Diez, Patricia; Gandon, Laura; Wynn-Jones, Andrea; Bownes, Peter; Lee, Chris; Aird, Edwin; Bidmead, Margaret; Lowe, Gerry; Bradley, David; Nisbet, Andrew

    2015-01-01

    Purpose: To undertake the first multicentre fully ‘end to end’ dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. Materials and methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. Results: The mean difference between planned and measured dose at Point A was −0.6% for plastic applicators and −3.0% for metal applicators, at standard uncertainty 3.0% (k = 1). Isodose distributions agreed within 1 mm over a dose range 2–16 Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2 mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. Conclusions: The concept of ‘end to end’ dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved

  19. Radiology

    International Nuclear Information System (INIS)

    Bigot, J.M.; Moreau, J.F.; Nahum, H.; Bellet, M.

    1990-01-01

    The 17th International Congress of Radiology was conducted in two separate scientific sessions, one for radiodiagnosis and one for radiation oncology. Topics covered are: Radiobiology -radioprotection; imaging and data processing; contrast media; MRI; nuclear medicine; radiology and disasters; radiology of tropical diseases; cardiovascular radiology; interventional radiology; imaging of trauma; imaging of chest, gastro-intestinal tract, breast and genito-urinary tract; imaging in gynecology;imaging in oncology; bone and joint radiology; head and neck-radiology; neuro-radiology. (H.W.). refs.; fig.; tabs

  20. High dose rate intraoperative radiation therapy (HDR-IORT) as part of the management strategy for locally advanced primary and recurrent rectal cancer

    International Nuclear Information System (INIS)

    Harrison, Louis B.; Minsky, Bruce D.; Enker, Warren E.; Mychalczak, Borys; Guillem, Jose; Paty, Philip B.; Anderson, Lowell; White, Carol; Cohen, Alfred M.

    1998-01-01

    Purpose: Primary unresectable and locally advanced recurrent rectal cancer presents a significant clinical challenge. Local failure rates are high in both situations. Under such circumstances, there is a significant need to safely deliver tumoricidal doses of radiation in an attempt to improve local control. For this reason, we have incorporated a new approach utilizing high dose rate intraoperative radiation therapy (HDR-IORT). Methods and Materials: Between 11/92-12/96, a total of 112 patients were explored, of which 68 patients were treated with HDR-IORT, and 66 are evaluable. The majority of the 44 patients were excluded for unresectable disease or for distant metastases which eluded preoperative imaging. There were 22 patients with primary unresectable disease, and 46 patients who presented with recurrent disease. The histology was adenocarcinoma in 64 patients, and squamous cell carcinoma in four patients. In general, the patients with primary unresectable disease received preoperative chemotherapy with 5-fluorouracil (5-FU) and leucovorin, and external beam irradiation to 4500-5040 cGy, followed by surgical resection and HDR-IORT (1000-2000 cGy). In general , the patients with recurrent disease were treated with surgical resection and HDR-IORT (1000-2000 cGy) alone. All surgical procedures were done in a dedicated operating room in the brachytherapy suite, so that HDR-IORT could be delivered using the Harrison-Anderson-Mick (HAM) applicator. The median follow-up is 17.5 months (1-48 mo). Results: In primary cases, the actuarial 2-year local control is 81%. For patients with negative margins, the local control was 92% vs. 38% for those with positive margins (p = 0.002). The 2-year actuarial disease-free survival was 69%; 77% for patients with negative margins vs. 38% for patients with positive margins (p = 0.03). For patients with recurrent disease, the 2-year actuarial local control rate was 63%. For patients with negative margins, it was 82%, while it was

  1. Comparison of high dose rate (HDR) and low dose rate (LDR) brachytherapy in the treatment of stage IIIB cervix cancer with radiation therapy alone. The preliminary results

    International Nuclear Information System (INIS)

    Trippe, Nivaldo; Novaes, P.E.; Ferrigno, R.; Pellizzon, A.C.; Salvajoli, J.V.; Fogaroli, R.C.; Maia, M.A.C.; Baraldi, H.E.

    1996-01-01

    Purpose/Objective: To compare the results between HDR and LDR brachytherapy in the treatment of stage IIIB cervix cancer with radiation therapy alone through a prospective and randomized trial. Materials and Methods: From September 1992 to December 1993, 65 patients with stage IIIB cervical cancer were randomized to one of the following treatment schedule according to the brachytherapy used to complement the dose of external beam radiotherapy (EBRT): 1 - High dose rate (HDR) - 36 patients - 4 weekly insertions of 6,0 Gy at point A 2 - Low dose rate (LDR) - 29 patients - 2 insertions two weeks apart of 17,5 Gy at point A The External Beam radiotherapy was performed through a Linac 4MV, in box arrangement for whole pelvis and in AP-PA fields for parametrial complementation of dose. The dose at the whole pelvis was 45 Gy in 25 fractions of 1,8 Gy and the parametrial dose was 16 Gy. The brachytherapy was realized with Fletcher colpostats and intrauterine tandem, in both arms. The HDR brachytherapy was realized through a Micro-Selectron device, working with Iridium-192 with initial activity of 10 Ci and started ten days after the beginning of EBRT. The total treatment time was shortened in two weeks for this group. The LDR brachytherapy started only after the end of EBRT. Results: With the minimum follow up of 24 months and medium of 31 months, the disease free survival was 50% among the 36 patients in HDR group and 47,8% among the 29 patients in LDR group. Local failures occurred in 50% and 52,8% respectively. Grade I and II complications were restricted to rectites and cistites and the incidence of them was 8,3% for HDR group and 13% for LDR group. Until the time of evaluation there were no grade III complications in any group. Conclusions: Although the number of patients is small and the time of follow up still short, these preliminary results suggest that the HDR brachytherapy has an equivalent efficiency in local control as the LDR in the treatment of stage IIIB

  2. A comprehensive study on HDR brachytherapy treatments of cervical cancers: using the first Co-60 BEBIG Multisource Unit in Bangladesh

    Directory of Open Access Journals (Sweden)

    Naheed Rukhsana

    2011-07-01

    Full Text Available Purpose: The report presents an extraordinary synthesis of customer acceptance procedures (CAP, quality assurance tests (QA in the treatment of cervical cancer patients, using the first Co-60 Multisource Unit® in Bangladesh. The QA and commissioning required measurements and emergency tests verifying the functional limits of parameters acceptable for the new HDR afterloader. Acceptable limits were: 1 the deviation between specified and measured source strength: ± 3%; 2 the positional accuracy and uniformity: ± 1 mm; 3 the temporal accuracy (i.e. timer error and linearity and end error: ± 1% or 30 sec.; 4 treatment planning system (digitizer and localization software: ± 3% or 1 mm; 5 the distance from line to first dwell position and all the others: 5 mm and 10 mm (± 1 mm. Material and methods: Till February 2011, 47 patients were treated with HDR with more than 140 insertions applied. Amongst them, 12 patients were in stage IIB and IIIB, 22 were postoperative (IA and IB while the remaining 13 patients were with unknown stage. All the cases with stage IIB and IIIB received concurrent chemo-radiation and brachytherapy. Postoperative patients received EBRT (50 Gy and HDR according to the institutional protocol. CT scans were completed before HDR-plus planning with a good reproducibility (± 2% and were documented in repeating the plan for the same set up of a patient. Absorbed dose (Gy to a point P, at a distance of “r” in centimeters from a source of the Reference Air Kerma Rate (RAKR has been utilized for the QA of the source, where source strength measurement was accomplished. Results: All methods and analysis applicable to the QA and commissioning of Co-60 have been investigated and systematically analyzed, measured and documented before the treatment of a patient. Studies and safety requirements of this HDR remote afterloader were carried out. Acceptance and the QA were imperative to justify functionality and dependability in

  3. A comprehensive study on HDR brachytherapy treatments of cervical cancers: using the first Co-60 BEBIG Multisource Unit in Bangladesh.

    Science.gov (United States)

    Malik, Sadiq R; Banu, Parvin A; Rukhsana, Naheed

    2011-06-01

    The report presents an extraordinary synthesis of customer acceptance procedures (CAP), quality assurance tests (QA) in the treatment of cervical cancer patients, using the first Co-60 Multisource Unit ® in Bangladesh. The QA and commissioning required measurements and emergency tests verifying the functional limits of parameters acceptable for the new HDR afterloader. Acceptable limits were: 1) the deviation between specified and measured source strength: ± 3%; 2) the positional accuracy and uniformity: ± 1 mm; 3) the temporal accuracy (i.e. timer error and linearity and end error): ± 1% or 30 sec.; 4) treatment planning system (digitizer and localization software): ± 3% or 1 mm; 5) the distance from line to first dwell position and all the others: 5 mm and 10 mm (± 1 mm). Till February 2011, 47 patients were treated with HDR with more than 140 insertions applied. Amongst them, 12 patients were in stage IIB and IIIB, 22 were postoperative (IA and IB) while the remaining 13 patients were with unknown stage. All the cases with stage IIB and IIIB received concurrent chemo-radiation and brachytherapy. Postoperative patients received EBRT (50 Gy and HDR) according to the institutional protocol. CT scans were completed before HDR-plus planning with a good reproducibility (± 2%) and were documented in repeating the plan for the same set up of a patient. Absorbed dose (Gy) to a point P, at a distance of "r" in centimeters from a source of the Reference Air Kerma Rate (RAKR) has been utilized for the QA of the source, where source strength measurement was accomplished. All methods and analysis applicable to the QA and commissioning of Co-60 have been investigated and systematically analyzed, measured and documented before the treatment of a patient. Studies and safety requirements of this HDR remote afterloader were carried out. Acceptance and the QA were imperative to justify functionality and dependability in delivering the treatment. Implications of these studies

  4. Implementation of the technique of partial irradiation accelerated the breast with high doses (HDR) brachytherapy; Puesta en marcha de la tecnica de irradiacion parcial acelerada de la mama con braquterapia de alta tasa de dosis (HDR)

    Energy Technology Data Exchange (ETDEWEB)

    Molina Lopez, M. Y.; Pardo Perez, E.; Castro Novais, J.; Martinez Ortega, J.; Ruiz Maqueda, S.; Cerro Penalver, E. del

    2013-07-01

    The objective of this work is presents procedure carried out in our Centre for the implementation of the accelerated partial breast irradiation (APBI, accelerated partial-breast irradiation) with high-rate brachytherapy (HDR), using plastic tubes as applicators. Carried out measures, the evaluation of the dosimetric parameters analyzing and presenting the results. (Author)

  5. SU-C-202-02: A Comprehensive Evaluation of Adaptive Daily Planning for Cervical Cancer HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Meerschaert, R; Paul, A; Zhuang, L [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Nalichowski, A [Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States); Burmeister, J; Miller, A [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States)

    2016-06-15

    Purpose: To evaluate adaptive daily planning for cervical cancer patients who underwent high-dose-rate intra-cavitary brachytherapy (HDR-ICBT). Methods: This study included 22 cervical cancer patients who underwent 5 fractions of HDR ICBT. Regions of interest (ROIs) including high-risk clinical tumor volume (HR-CTV) and organs-at-risk (OARs) were manually contoured on daily CT images. All patients were treated with adaptive daily plans, which involved ROI delineation and dose optimization at each treatment fraction. Single treatment plans were retrospectively generated by applying the first treatment fraction’s dwell times adjusted for decay and dwell positions of the applicator to subsequent treatment fractions. Various existing similarity metrics were calculated for the ROIs to quantify interfractional organ variations. A novel similarity score (JRARM) was established, which combined both volumetric overlap metrics (DSC, JSC, and RVD) and distance metrics (ASD, MSD, and RMSD). Linear regression was performed to determine a relationship between inter-fractional organ variations of various similarity metrics and D2cc variations from both plans. Wilcoxon Signed Rank Tests were used to assess adaptive daily plans and single plans by comparing EQD2 D2cc (α/β=3) for OARs. Results: For inter-fractional organ variations, the sigmoid demonstrated the greatest variations based on the JRARM and DSC similarity metrics. Comparisons between paired ROIs showed differences in JRARM scores and DSCs at each treatment fraction. RVD, MSD, and RMSD were found to be significantly correlated to D2cc variations for bladder and sigmoid. The comparison between plans found that adaptive daily planning provided lower EQD2 D2cc of OARs than single planning, specifically for the sigmoid (p=0.015). Conclusion: Substantial inter-fractional organ motion can occur during HDR-BT, which may significantly affect D2cc of OARs. Adaptive daily planning provides improved dose sparing for OARs

  6. Speedup of optimization-based approach to local backlight dimming of HDR displays

    DEFF Research Database (Denmark)

    Burini, Nino; Nadernejad, Ehsan; Korhonen, Jari

    2012-01-01

    Local backlight dimming in Liquid Crystal Displays (LCD) is a technique for reducing power consumption and simultaneously increasing contrast ratio to provide a High Dynamic Range (HDR) image reproduction. Several backlight dimming algorithms exist with focus on reducing power consumption, while...... other algorithms aim at enhancing contrast, with power savings as a side effect. In our earlier work, we have modeled backlight dimming as a linear programming problem, where the target is to minimize the cost function measuring the distance between ideal and actual output. In this paper, we propose...

  7. Interactive, multi-modality image registrations for combined MRI/MRSI-planned HDR prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Galen Reed

    2011-03-01

    Full Text Available Purpose: This study presents the steps and criteria involved in the series of image registrations used clinically during the planning and dose delivery of focal high dose-rate (HDR brachytherapy of the prostate. Material and methods: Three imaging modalities – Magnetic Resonance Imaging (MRI, Magnetic Resonance Spectroscopic Imaging (MRSI, and Computed Tomography (CT – were used at different steps during the process. MRSI is used for identification of dominant intraprosatic lesions (DIL. A series of rigid and nonrigid transformations were applied to the data to correct for endorectal-coil-induced deformations and for alignment with the planning CT. Mutual information was calculated as a morphing metric. An inverse planning optimization algorithm was applied to boost dose to the DIL while providing protection to the urethra, penile bulb, rectum, and bladder. Six prostate cancer patients were treated using this protocol. Results: The morphing algorithm successfully modeled the probe-induced prostatic distortion. Mutual information calculated between the morphed images and images acquired without the endorectal probe showed a significant (p = 0.0071 increase to that calculated between the unmorphed images and images acquired without the endorectal probe. Both mutual information and visual inspection serve as effective diagnostics of image morphing. The entire procedure adds less than thirty minutes to the treatment planning. Conclusion: This work demonstrates the utility of image transformations and registrations to HDR brachytherapy of prostate cancer.

  8. Commissioning of a well type chamber for HDR and LDR brachytherapy applications: a review of methodology and outcomes.

    Science.gov (United States)

    Mukwada, Godfrey; Neveri, Gabor; Alkhatib, Zaid; Waterhouse, David K; Ebert, Martin

    2016-03-01

    For safe and accurate dose delivery in brachytherapy, associated equipment is subject to commissioning and ongoing quality assurance (QA). Many centres depend on the use of a well-type chamber ('well chamber') for performing brachytherapy dosimetry. Documentation of well chamber commissioning is scarce despite the important role the chamber plays in the whole brachytherapy QA process. An extensive and structured commissioning of the HDR 1000 plus well chamber (Standard Imaging Inc, Middleton WI) for HDR and LDR dosimetry was undertaken at Sir Charles Gairdner Hospital. The methodology and outcomes of this commissioning is documented and presented as a guideline to others involved in brachytherapy. The commissioning tests described include mechanical integrity, leakage current, directional dependence, response, length of uniform response, the influence of insert holders, ion collection efficiency, polarity effect, accuracy of measured air kerma strength (S(K)) or reference air kerma rate (K(R)) and baseline setting (for ongoing constancy checks). For the HDR 1000 plus well chamber, some of the insert holders modify the response curve. The measured sweet length was 2.5 cm which is within 0.5% of that specified by the manufacturer. Correction for polarity was negligible (0.9999) and ion recombination was small (0.9994). Directional dependence was small (less than 0.2%) and leakage current was negligible. The measured K(R) for (192)Ir agreed within 0.11% compared with a second well chamber of similar model and was within 0.5% of that determined via a free-in-air measurement method. Routine constancy checks over a year agreed with the baseline within 0.4%.

  9. HDR flood-water storage-tank modal vibration tests

    International Nuclear Information System (INIS)

    Gorman, V.W.; Thinnes, G.L.

    1983-01-01

    Modal vibration tests were conducted by EG and G Idaho on two vessels located at West Germany's Heissdampfreaktor (HDR) facility which is 25 kilometers east of Frankfurt. The tests were performed during May and June 1982 for the US Nuclear Regulatory Commission (NRC) as part of their cooperative effort with Kernforschungszentrum Karlsruhe (KfK) of West Germany. The primary purpose for performing this task was to determine modal properties (frequencies, mode shapes and associated damping ratios) in order to eventually provide guidelines for standards development by the NRC in modeling similar vessels. One of the vessels tested was a flood water storage tank (FWST) for empty, half full and full water conditions. The FWST was excited randomly with an electromagnetic shaker and by impulsive hammer blows. Excitation or input forces together with measured vessel responses were processed by a digital modal analyzer and stored on magnetic disks for subsequent evaluation

  10. Distribution of hydrogen within the HDR-containment under severe accident conditions. OECD standard problem. Final comparison report

    Energy Technology Data Exchange (ETDEWEB)

    Karwat, H

    1992-08-15

    The present report summarizes the results of the International Standard Problem Exercise ISP-29, based on the HDR Hydrogen Distribution Experiment E11.2. Post-test analyses are compared to experimentally measured parameters, well-known to the analysis. This report has been prepared by the Institute for Reactor Dynamics and Reactor Safety of the Technical University Munich under contract with the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) which received funding for this activity from the German Ministry for Research and Technology (BMFT) under the research contract RS 792. The HDR experiment E11.2 has been performed by the Kernforschungszentrum Karlsruhe (KfK) in the frame of the project 'Projekt HDR-Sicherheitsprogramm' sponsored by the BMFT. Ten institutions from eight countries participated in the post-test analysis exercise which was focussing on the long-lasting gas distribution processes expected inside a PWR containment under severe accident conditions. The gas release experiment was coupled to a long-lasting steam release into the containment typical for an unmitigated small break loss-of-coolant accident. In lieu of pure hydrogen a gas mixture consisting of 15% hydrogen and 85% helium has been applied in order to avoid reaching flammability during the experiment. Of central importance are common overlay plots comparing calculated transients with measurements of the global pressure, the local temperature-, steam- and gas concentration distributions throughout the entire HDR containment. The comparisons indicate relatively large margins between most calculations and the experiment. Having in mind that this exercise was specified as an 'open post-test' analysis of well-known measured data the reasons for discrepancies between measurements and simulations were extensively discussed during a final workshop. It was concluded that analytical shortcomings as well as some uncertainties of experimental boundary conditions may be responsible for deviations

  11. Distribution of hydrogen within the HDR-containment under severe accident conditions. OECD standard problem. Final comparison report

    International Nuclear Information System (INIS)

    Karwat, H.

    1992-08-01

    The present report summarizes the results of the International Standard Problem Exercise ISP-29, based on the HDR Hydrogen Distribution Experiment E11.2. Post-test analyses are compared to experimentally measured parameters, well-known to the analysis. This report has been prepared by the Institute for Reactor Dynamics and Reactor Safety of the Technical University Munich under contract with the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) which received funding for this activity from the German Ministry for Research and Technology (BMFT) under the research contract RS 792. The HDR experiment E11.2 has been performed by the Kernforschungszentrum Karlsruhe (KfK) in the frame of the project 'Projekt HDR-Sicherheitsprogramm' sponsored by the BMFT. Ten institutions from eight countries participated in the post-test analysis exercise which was focussing on the long-lasting gas distribution processes expected inside a PWR containment under severe accident conditions. The gas release experiment was coupled to a long-lasting steam release into the containment typical for an unmitigated small break loss-of-coolant accident. In lieu of pure hydrogen a gas mixture consisting of 15% hydrogen and 85% helium has been applied in order to avoid reaching flammability during the experiment. Of central importance are common overlay plots comparing calculated transients with measurements of the global pressure, the local temperature-, steam- and gas concentration distributions throughout the entire HDR containment. The comparisons indicate relatively large margins between most calculations and the experiment. Having in mind that this exercise was specified as an 'open post-test' analysis of well-known measured data the reasons for discrepancies between measurements and simulations were extensively discussed during a final workshop. It was concluded that analytical shortcomings as well as some uncertainties of experimental boundary conditions may be responsible for deviations

  12. SU-E-T-758: To Determine the Source Dwell Positions of HDR Brachytherapy Using 2D 729 Ion Chamber Array

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Syam [Malabar Cancer Centre, Kannur, Kerala (India); Sitha [University of Calicut, Calicut, Kerala (India)

    2015-06-15

    Purpose: Determination of source dwell positions of HDR brachytherapy using 2D 729 ion chamber array Methods: Nucletron microselectron HDR and PTW 2D array were used for the study. Different dwell positions were assigned in the HDR machine. Rigid interstitial needles and vaginal applicator were positioned on the 2D array. The 2D array was exposed for this programmed dwell positions. The positional accuracy of the source was analyzed after the irradiation of the 2D array. This was repeated for different dwell positions. Different test plans were transferred from the Oncentra planning system and irradiated with the same applicator position on the 2D array. The results were analyzed using the in house developed excel program. Results: Assigned dwell positions versus corresponding detector response were analyzed. The results show very good agreement with the film measurements. No significant variation found between the planned and measured dwell positions. Average dose response with 2D array between the planned and nearby dwell positions was found to be 0.0804 Gy for vaginal cylinder applicator and 0.1234 Gy for interstitial rigid needles. Standard deviation between the doses for all the measured dwell positions for interstitial rigid needle for 1 cm spaced positions were found to be 0.33 and 0.37 for 2cm spaced dwell positions. For intracavitory vaginal applicator this was found to be 0.21 for 1 cm spaced dwell positions and 0.06 for 2cm spaced dwell positions. Intracavitory test plans reproduced on the 2D array with the same applicator positions shows the ideal dose distribution with the TPS planned. Conclusion: 2D array is a good tool for determining the dwell position of HDR brachytherapy. With the in-house developed program in excel it is easy and accurate. The traditional way with film analysis can be replaced by this method, as the films will be more costly.

  13. SU-E-T-758: To Determine the Source Dwell Positions of HDR Brachytherapy Using 2D 729 Ion Chamber Array

    International Nuclear Information System (INIS)

    Kumar, Syam; Sitha

    2015-01-01

    Purpose: Determination of source dwell positions of HDR brachytherapy using 2D 729 ion chamber array Methods: Nucletron microselectron HDR and PTW 2D array were used for the study. Different dwell positions were assigned in the HDR machine. Rigid interstitial needles and vaginal applicator were positioned on the 2D array. The 2D array was exposed for this programmed dwell positions. The positional accuracy of the source was analyzed after the irradiation of the 2D array. This was repeated for different dwell positions. Different test plans were transferred from the Oncentra planning system and irradiated with the same applicator position on the 2D array. The results were analyzed using the in house developed excel program. Results: Assigned dwell positions versus corresponding detector response were analyzed. The results show very good agreement with the film measurements. No significant variation found between the planned and measured dwell positions. Average dose response with 2D array between the planned and nearby dwell positions was found to be 0.0804 Gy for vaginal cylinder applicator and 0.1234 Gy for interstitial rigid needles. Standard deviation between the doses for all the measured dwell positions for interstitial rigid needle for 1 cm spaced positions were found to be 0.33 and 0.37 for 2cm spaced dwell positions. For intracavitory vaginal applicator this was found to be 0.21 for 1 cm spaced dwell positions and 0.06 for 2cm spaced dwell positions. Intracavitory test plans reproduced on the 2D array with the same applicator positions shows the ideal dose distribution with the TPS planned. Conclusion: 2D array is a good tool for determining the dwell position of HDR brachytherapy. With the in-house developed program in excel it is easy and accurate. The traditional way with film analysis can be replaced by this method, as the films will be more costly

  14. Dose rate effect from the relationship between ICRU rectal dose and local control rate in intracavitary radiotherapy for carcinoma of the uterine cervix. Six fraction HDR and three-fraction LDR in three weeks

    International Nuclear Information System (INIS)

    Jingu, Kenichi; Akita, Yuzou; Ohmagari, Jyunichi

    2001-01-01

    The dose rate effect, low dose rate radiotherapy (LDR)/high dose rate radiotherapy (HDR), was calculated using the isoeffect ICRU rectal dose by intracavitary radiotherapy (ICRT) for uterine cervix cancer. The subjects analyzed consisted of 78 LDR and 74 HDR patients whose ICRU rectal dose could be calculated and whose local control as stage II/III cases could be evaluated. The point A dose in ICRT was 45-55 Gy/3 fractions/3 weeks for LDR and 30 Gy/6 fractions/3 weeks for HDR. The dose effect relationships associated with local control at each whole pelvis external radiation dose were calculated using the double integration method and Probit analysis, and the 50% and 90% local control ICRU rectal doses were calculated from this relationship. Finally, the dose rate effect LDR/HDR was determined from 50% and 90% local control doses. The dose rate effect calculated from the 50% local control dose was 1.24 and that from the 90% local control dose was 1.14. (author)

  15. Comparison of the cost between 60Co and 192Ir, as the sources for high-dose-rate remote control afterloading systems (HDR-RALS)

    International Nuclear Information System (INIS)

    Ogata, Hitoshi

    1994-01-01

    High-Dose-Rate remote control afterloading systems (HDR-RALS) installing 60 Co sources have been prevailing currently in Japan. The survey conducted by Japan Isotope Association (JIA) reports that 180 machines are at working condition. Although the wide prevalence of the HDR-RALS, the stable supply of 60 Co is becoming difficult because of the short availability of raw materials. The supply of 60 Co is planned to be terminated in March 1996. In place of 60 Co, 192 Ir is going to be produced in 1996. The size of 192 Ir, which is much smaller than that of 60 Co, may facilitate broader clinical usability. On the other hand, for the reason that the half life of 192 Ir (73.8 days) is much shorter than that of 60 Co (5.27 years), several exchanges of the sources in a year are necessary. This report analyses the difference of the cost between 60 Co and 192 Ir as the sources for HDR-RALS. As the cost of the 60 Co sources is dependent on the distance from Tokyo. Radiation activity, etc., the cost-calculation was done on the basis the 60 Co sources were installed for the HDR-RALS systems in Yamanashi Central Hospital. The total cost of 60 Co is 3,377,000 yen on the data from JIA. According to the half life of 5.27 years, the available duration can be thought as 7 years and the monthly cost be calculated as about 40,000 yen. In case of 192 Ir, the prices for Buchler' system and Nucletron's system are 800,000 yen and 990,000 yen respectively. Concerning the shortness of the half life, an exchange in every 3 months is ideal. Therefore the monthly cost of 192 Ir would be 260,000-330,000 yen. Consequently the cost-ratio for 192 Ir and 60 Co would become 6.7-8.3. The cost of intracavitary irradiation is controlled by the government as 10,000 yen per treatment in Japan. If this setting remains the same for HDR-RALS installing 192 Ir, almost all the facilities of radiation therapy would suffer from the cost-income inbalance in the near future. (author)

  16. SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual approach.

  17. SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    International Nuclear Information System (INIS)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

    2016-01-01

    Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual approach.

  18. Poster - Thur Eve - 03: LDR to HDR: RADPOS applications in brachytherapy.

    Science.gov (United States)

    Cherpak, A J; Cygler, J E; Kertzscher, G; E, C; Perry, G

    2012-07-01

    The RADPOS in vivo dosimetry system combines an electromagnetic positioning sensor and either one or five MOSFET dosimeters. The feasibility of using the system for quality control has been explored for a range of radiotherapy treatment techniques including most recently transperineal interstitial permanent prostate brachytherapy and high dose rate (HDR) treatments. Dose and position information was collected by a RADPOS array detector inside a Foley catheter within patients' urethra during permanent seed implantation. Ten patients were studied, and average displacement during implantation was Δr = (1.4-5.1) mm, with movements up to 9.7 mm due to the removal of the transrectal ultrasound probe. Maximum integral dose in the prostatic urethra ranged from 110-195 Gy, and it was found that the dose can change up to 63 cGy (62.0%) depending on whether the rectal probe is in place. For HDR, a RADPOS detector was first calibrated with an Ir-192 source. A treatment was then simulated using a total of 50 dwell positions in 5 catheters in an acrylic phantom. Dwell positions ranged from 1 to 10 cm away from the RADPOS detector and dose was measured for each source position. An average calibration coefficient of 0.74±0.11 cGy/mV was calculated for the detector and the average absolute difference between measured values and expected dose was 0.7±5.4 cGy (5±20%). The demonstrated accuracy of RADPOS dose measurements along with its ability to simultaneously measure displacement makes it a powerful tool for brachytherapy treatments, where high dose gradients can present unique in vivo dosimetry challenges. © 2012 American Association of Physicists in Medicine.

  19. Pre- and post-calculations for crack opening and leak rate experiments on piping components within the HDR-program

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1991-01-01

    In this paper calculations to experiments on leak opening and leak rates of piping components are presented. The experiments are performed at the HDR-facility at Karlstein/Germany and up to now straight pipes and pipe branches were considered. Numerical and experimental results are compared. (author)

  20. SU-F-T-31: Shape and Isodose Distributions in Co60 HDR Brachytherapy for Different Utero-Vaginal Time Ratios

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Sprinberg, G [Faculty of Sciences, Montevideo, Montevideo (Venezuela, Bolivarian Republic of); Piriz, G [Hospital Pereyra Rossell, Montevideo, Montevideo (Venezuela, Bolivarian Republic of)

    2016-06-15

    Purpose: To optimize the dose in bladder and rectum and show the different shapes of the isodose volumes in Co60-HDR brachytherapy, considering different utero and vaginal sources dwell ratio times (TU:TV). Methods: Besides Ir192-HDR, new Co60-HDR sources are being incorporated. We considered different TU:TV times and computed the dosis in bladder, rectum and at the reference points of the Manchester system. Also, we calculated the isodose volume and shape in each case. We used a EZAG-BEBIG Co0.A86 model with TPS HDRplus3.0.4. and LCT42-7, LCT42-2(R,L) applicators. A reference dose RA= 1.00 Gy was given to the A-right point. We considered the TU:TV dwell time ratios 1:0.25, 1:0.33, 1:0.5, 1:1, 1:2, 1:3, and 1:4. Given TU:TV, the stop time at each dwell position is fixed for each applicator. Results: Increasing TU:TV systematically results in a decreasing of the dose in bladder and rectum, e.g. 9% and 27% reduction were found in 1:0.25 with respect to 1:1, while 12% and 34% increase were found in 1:4 with respect to 1:1. Also, the isodose volume parameters height (h), width (w), thickness (t) and volume (hwt) increased from the 1:0.25 case to the 1:4 value: hwt is 25% lower and 31% higher than the 1:1 reference volume in these cases. Also w decreased for higher TU:TV and may compromise the tumoral volume coverage, decreasing 17% in the 1:0.25 case compared to the 1:1 case. The shape of the isodose volume was obtained for the different TU:TV considered. Conclusion: We obtained the shape of isodose volumes for different TU:TV values in gynecological Co60-HDR. We studied the dose reduction in bladder and rectum for different TU:TV ratios. The volume parameters and hwt are strongly dependent on this ratio. This information is useful for a quantitative check of the TPS and as a starting point towards optimization.

  1. Late complications after high-dose-rate interstitial brachytherapy for tongue cancer

    International Nuclear Information System (INIS)

    Shimizutani, Kimishige; Inoue, Takehiro; Inoue, Toshihiko; Yoshioka, Yasuo; Teshima, Teruki; Kakimoto, Naoya; Murakami, Shumei; Furukawa, Souhei; Fuchihata, Hajime

    2005-01-01

    The objectives of this study was to analyze the treatment results and late complications of high-dose-rate (HDR) interstitial brachytherapy (ISBT) for early (T1N0, T2N0) mobile tongue cancer using the microSelectron-HDR. From January 1993 through April 2001, a total of 72 patients with early squamous cell carcinomas of the mobile tongue were treated with microSelectron-HDR interstitial brachytherapy at the Department of Radiology, Osaka University Hospital. Of the patients, 18% were treated with a combination of prior external radiation and HDR-ISBT, and 82% were treated with HDR-ISBT alone. For HDR-ISBT alone, all cases were treated with a total dose of 54 Gy/9 fractions every 5 days or 60 Gy/10 fractions every 8 days. In combined therapy with an external dose of 30 to 40 Gy, HDR-ISBT was given at a total dose of 42-50 Gy. The Brinkman and alcohol indexes were used to analyze the incidence of late complications after HDR-ISBT. The 2- and 5-year local control rates were 85% and 82%, respectively. Fifteen of 72 patients (21%) treated with HDR-ISBT had late complications. Ten of 15 patients (67%) with late complications had a Brinkman index exceeding 600. HDR-ISBT is useful and easily applied under local anesthesia to early or superficial lesions of the mobile tongue. However, we found an increase in late complications, such as soft-tissue ulcers and bone exposure, after irradiation of tongue cancer with 60 Gy HDR-ISBT in patients with a Brinkman index greater than 600. (author)

  2. Estimation of distance error by fuzzy set theory required for strength determination of HDR (192)Ir brachytherapy sources.

    Science.gov (United States)

    Kumar, Sudhir; Datta, D; Sharma, S D; Chourasiya, G; Babu, D A R; Sharma, D N

    2014-04-01

    Verification of the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm(3) is one of the recommended methods for measuring RAKR of HDR (192)Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR (192)Ir source strength measurement.

  3. Radiology today

    International Nuclear Information System (INIS)

    Donner, M.W.; Heuck, F.H.W.

    1981-01-01

    The book encompasses the proceedings of a postgraduate course held in Salzburg in June 1980. 230 radiologists from 17 countries discussed here the important and practical advances of diagnostic radiology, nuclear medicine and ultrasound as they contribute to gastrointestinal, urologic, skeletal, cardiovascular, pediatric, and neuroradiology. The book contains 55 single contributions of different authors to the following main themes: Cardiovascular, Radiology, pulmonary radiology, gastrointestinal radiology, urinary tract radiology, skeletal radiology, mammography, lymphography, ultrasound, ENT radiology, and neuroradiology. (orig./MG)

  4. TU-D-201-06: HDR Plan Prechecks Using Eclipse Scripting API

    Energy Technology Data Exchange (ETDEWEB)

    Palaniswaamy, G; Morrow, A; Kim, S; Rangaraj, D [Baylor Scott & White Health, Temple, TX (United States)

    2016-06-15

    Purpose: Automate brachytherapy treatment plan quality check using Eclipse v13.6 scripting API based on pre-configured rules to minimize human error and maximize efficiency. Methods: The HDR Precheck system is developed based on a rules-driven approach using Eclipse scripting API. This system checks for critical plan parameters like channel length, first source position, source step size and channel mapping. The planned treatment time is verified independently based on analytical methods. For interstitial or SAVI APBI treatment plans, a Patterson-Parker system calculation is performed to verify the planned treatment time. For endobronchial treatments, an analytical formula from TG-59 is used. Acceptable tolerances were defined based on clinical experiences in our department. The system was designed to show PASS/FAIL status levels. Additional information, if necessary, is indicated appropriately in a separate comments field in the user interface. Results: The HDR Precheck system has been developed and tested to verify the treatment plan parameters that are routinely checked by the clinical physicist. The report also serves as a reminder or checklist for the planner to perform any additional critical checks such as applicator digitization or scenarios where the channel mapping was intentionally changed. It is expected to reduce the current manual plan check time from 15 minutes to <1 minute. Conclusion: Automating brachytherapy plan prechecks significantly reduces treatment plan precheck time and reduces human errors. When fully developed, this system will be able to perform TG-43 based second check of the treatment planning system’s dose calculation using random points in the target and critical structures. A histogram will be generated along with tabulated mean and standard deviation values for each structure. A knowledge database will also be developed for Brachyvision plans which will then be used for knowledge-based plan quality checks to further reduce

  5. Evaluation of Wall Correction Factor of INER's Air-Kerma Primary Standard Chamber and Dose Variation by Source Displacement for HDR 192Ir Brachytherapy

    Directory of Open Access Journals (Sweden)

    J. H. Lee

    2013-01-01

    Full Text Available The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR 192Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan. The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the 192Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA and the National Physical Laboratory (NPL, UK for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR 192Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR 192Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  6. Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

    Science.gov (United States)

    de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

    2016-01-01

    To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

  7. Vaginal HDR-afterloading in the treatment of endometrial carcinoma - analysis of side effects and relapse rates

    International Nuclear Information System (INIS)

    Weiss, E.; Arnold-Bofinger, H.; Weidner, N.; Hirnle, P.; Bamberg, M.

    1996-01-01

    Introduction: In a retrospective analysis side effects, relapse rates and the value of in vivo dosimetry for vaginal HDR-brachytherapy (BT) in women with endometrial carcinoma are evaluated. Material and Methods: From 1987 to 1993 124 women received vaginal HDR-BT (Ir-192) only for adjuvant treatment of early endometrial carcinoma. The usual fractionation was 1x7 Gy per week applied to the surface of the vaginal cylinder to a total dose of 21 Gy. During BT we performed in vivo dosimetry using bladder and rectal probes. The measured doses per patient in the bladder ranged from 1.5 to 9.8 Gy, 6.7 Gy in the mean. In the rectum the mean dose was 8.2 Gy (1.7 to 13.8 Gy). Results: The analysis of side effects shows that only 23 of 124 women (18 %) reported any problems at all. 13 women (10 %) noticed dysuria or pollakisuria for a maximum of 6 weeks. The average measured bladder dose in those patients was 5.3 Gy, (below the average bladder dose of 6.7 Gy). Diarrhea was reported in 3 patients (2 %), in those the average measured rectal dose was 6.8 Gy (lower than the average rectal dose of 8.2 Gy). 6 women (5 %) received antibiotic treatment because of bacteriuria. Of all patients 10 (8%) had a pelvic relapse, 3 in the vagina only. 5 women showed distant metastases during follow-up (3 of those having also a local relapse). Discussion and Conclusion: With only 2 % vaginal relapses HDR-BT is a save method to reduce the probability of vaginal metastases of endometrial carcinoma in an adjuvant setting. Moreover the incidence of acute side effects is low, no lasting complications were seen in our patients. There existed no correlation between the incidence of side effects and the measured in vivo doses in bladder and rectum, questioning the future usage in the era of well advanced BT-planning systems

  8. Pediatric radiology for medical-technical radiology assistants/radiologists

    International Nuclear Information System (INIS)

    Oppelt, Birgit

    2010-01-01

    The book on pediatric radiology includes the following chapter: differences between adults and children; psycho-social aspects concerning the patient child in radiology; relevant radiation doses in radiology; help for self-help: simple phantoms for image quality estimation in pediatric radiology; general information; immobilization of the patient; pediatric features for radiological settings; traumatology; contrast agents; biomedical radiography; computerized tomography; NMR imaging; diagnostic ultrasonography; handling of stress practical recommendations; medical displays.

  9. 192Ir high dose rate (HDR) interstitial brain implant: optimisation

    International Nuclear Information System (INIS)

    Tyagi, Anuj; Singh, Dinesh; Chitra, S.; Gupta, J.P.

    2001-01-01

    The new modality of stepping source dosimetry system (SSDs) illustrates a remarkable improvement in attaining the uniform and homogeneous dose distribution within the target volume. The technique enables the physicist to correct for a certain amount of misplacement or curvature of implant geometry. The short course of brachytherapy provides good palliation in terms of functional improvements with low and acceptable toxicity in high-grade glioma. With continual refinements of the technique, brachytherapy performed by a skilled brachytherapy team offers an opportunity to improve patient survival and quality of life. Since 1997, micro selectron HDR 192 Ir treatments are done including gynecological, oesophageal, breast, surface mould, soft tissue sarcoma (STS) and brain in our hospital. In this paper, procedure of interstitial brain implant in glioma as implant technique, simulation and treatment planning will be discussed

  10. HDR Brachytherapy in the Management of High-Risk Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Susan Masson

    2012-01-01

    Full Text Available High-dose-rate (HDR brachytherapy is used with increasing frequency for the treatment of prostate cancer. It is a technique which allows delivery of large individual fractions to the prostate without exposing adjacent normal tissues to unacceptable toxicity. This approach is particularly favourable in prostate cancer where tumours are highly sensitive to dose escalation and to increases in radiotherapy fraction size, due to the unique radiobiological behaviour of prostate cancers in contrast with other malignancies. In this paper we discuss the rationale and the increasing body of clinical evidence for the use of this technique in patients with high-risk prostate cancer, where it is combined with external beam radiotherapy. We highlight practical aspects of delivering treatment and discuss toxicity and limitations, with particular reference to current practice in the United Kingdom.

  11. Enrichment of G2/M cell cycle phase in human pluripotent stem cells enhances HDR-mediated gene repair with customizable endonucleases.

    Science.gov (United States)

    Yang, Diane; Scavuzzo, Marissa A; Chmielowiec, Jolanta; Sharp, Robert; Bajic, Aleksandar; Borowiak, Malgorzata

    2016-02-18

    Efficient gene editing is essential to fully utilize human pluripotent stem cells (hPSCs) in regenerative medicine. Custom endonuclease-based gene targeting involves two mechanisms of DNA repair: homology directed repair (HDR) and non-homologous end joining (NHEJ). HDR is the preferred mechanism for common applications such knock-in, knock-out or precise mutagenesis, but remains inefficient in hPSCs. Here, we demonstrate that synchronizing synchronizing hPSCs in G2/M with ABT phase increases on-target gene editing, defined as correct targeting cassette integration, 3 to 6 fold. We observed improved efficiency using ZFNs, TALENs, two CRISPR/Cas9, and CRISPR/Cas9 nickase to target five genes in three hPSC lines: three human embryonic stem cell lines, neural progenitors and diabetic iPSCs. neural progenitors and diabetic iPSCs. Reversible synchronization has no effect on pluripotency or differentiation. The increase in on-target gene editing is locus-independent and specific to the cell cycle phase as G2/M phase enriched cells show a 6-fold increase in targeting efficiency compared to cells in G1 phase. Concurrently inhibiting NHEJ with SCR7 does not increase HDR or improve gene targeting efficiency further, indicating that HR is the major DNA repair mechanism after G2/M phase arrest. The approach outlined here makes gene editing in hPSCs a more viable tool for disease modeling, regenerative medicine and cell-based therapies.

  12. SU-G-201-15: Nomogram as an Efficient Dosimetric Verification Tool in HDR Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liang, J; Todor, D [Virginia Commonwealth University, Richmond, VA (United States)

    2016-06-15

    Purpose: Nomogram as a simple QA tool for HDR prostate brachytherapy treatment planning has been developed and validated clinically. Reproducibility including patient-to-patient and physician-to-physician variability was assessed. Methods: The study was performed on HDR prostate implants from physician A (n=34) and B (n=15) using different implant techniques and planning methodologies. A nomogram was implemented as an independent QA of computer-based treatment planning before plan execution. Normalized implant strength (total air kerma strength Sk*t in cGy cm{sup 2} divided by prescribed dose in cGy) was plotted as a function of PTV volume and total V100. A quadratic equation was used to fit the data with R{sup 2} denoting the model predictive power. Results: All plans showed good target coverage while OARs met the dose constraint guidelines. Vastly different implant and planning styles were reflected on conformity index (entire dose matrix V100/PTV volume, physician A implants: 1.27±0.14, physician B: 1.47±0.17) and PTV V150/PTV volume ratio (physician A: 0.34±0.09, physician B: 0.24±0.07). The quadratic model provided a better fit for the curved relationship between normalized implant strength and total V100 (or PTV volume) than a simple linear function. Unlike the normalized implant strength versus PTV volume nomogram which differed between physicians, a unique quadratic model based nomogram (Sk*t)/D=−0.0008V2+0.0542V+1.1185 (R{sup 2}=0.9977) described the dependence of normalized implant strength on total V100 over all the patients from both physicians despite two different implant and planning philosophies. Normalized implant strength - total V100 model also generated less deviant points distorting the smoothed ones with a significantly higher correlation. Conclusion: A simple and universal, excel-based nomogram was created as an independent calculation tool for HDR prostate brachytherapy. Unlike similar attempts, our nomogram is insensitive to implant

  13. Requirements tests for QC of microSelectron-HDR

    International Nuclear Information System (INIS)

    Gesheva-Atanasova, N.; Gogova, A.; Peycheva, S.; Constantinov, B.; Ganchev, M.

    2000-01-01

    The Quality Control (QC) considers checks and measurements with the purpose of reconstruction, maintaining and increasing the quality of medical procedures and equipment. The QC tests for micro Selectron HDR afterloading machine with 192 Ir which allows more precise calculation and realisation of the tumour's dose have been created and introduced regularly in National Oncological Centre, Sofia. This paper has been cover the machine and software performance, source positioning, application equipment and radiation safety. A list of tests, their frequency, tolerance and action levels, as well as the tests' procedures have been worked out. The used methods are based on establishment of QC protocols. The documents have achieved for a certain period of time and they are available at any time. The experience shows drastically reduction of failures during medical treatment, ensuring the reliability of the used equipment and confidence that all the patients have treated adequate. Where some parameter is above the tolerance is it possible to do proper corrections measures immediately. This QA protocols give assurance that specific objectives being successfully met

  14. Radiological Worker Training: Radiological Worker 2 study guides

    International Nuclear Information System (INIS)

    1992-10-01

    Upon completion of this training course, the participant will have the knowledge to work safely in areas controlled for radiological purposes using proper radiological practices. Radiological Worker H Training, for the worker whose job assignment involves entry into Radiological Buffer Areas and all types of Radiation Contamination and Airborne Radioactivity Areas. This course is designed to prepare the worker to work safely in and around radiological areas and present methods to use to ensure individual radiation exposure is maintained As Low As Reasonably Achievable

  15. Structural safety of HDR reactor building during large scale vibration tests

    International Nuclear Information System (INIS)

    Stangenberg, F.; Zinn, R.

    1985-01-01

    In the second phase of the HDR investigations, a high shaker excitation of the building is planned using a large shaker which will be located on the operating floor and will be brought up to speed in a balanced condition and then unbalanced and decoupled from the drive system. With decreasing speed the shaker comes in resonance with the building frequencies and its energy is transferred to the building. In this paper the structural safety of the reactor building during the projected shaker tests is analysed. Dynamic response calculations with coupling between building and shaker by simultaneously integrating the equilibrium equations of both building and shaker are presented. The resulting building stresses, soil pressures etc. are compared with allowable values. (orig.)

  16. Radiological clerkships as a critical curriculum component in radiology education

    International Nuclear Information System (INIS)

    Kourdioukova, Elena V.; Verstraete, Koenraad L.; Valcke, Martin

    2011-01-01

    Objective: The aim of this research was to explore the perceived value of clinical clerkships in the radiology curriculum as well as the impact of radiology clerkship on students' beliefs about the profession of radiology as a whole and as a career. Methods: This study is a sequel to a previous survey in which student perceptions about radiology curriculum components were investigated. The present study focuses on a further analysis of a subsection in this study, based on 14 statements about radiology clerkship and two statements about radiology as a career. Results: Perceived usefulness of the aspects of radiology clerkship as 'radiology examination', 'skills development' and 'diagnosis focus' were awarded the highest scores. The predict value of the subscale 'radiology examination' on the level of performance was very high (adjusted R 2 = 0.19, p < .001). Conclusion: Students expressed highly favorable evaluation of clerkship as a learning environment to learn to order and to interpret imaging studies as well as an unique possibility to attend various radiological examinations and to access to specific radiology software systems, as well as to get a better view on radiology and to improve image interpretation skills. This positive attitude towards clerkship is closely tied to students' beliefs about the profession of radiology as a whole. These aspects of dedicated radiology clerkship are crucial for effective and high-quality education as well as for the choice of radiology as a career.

  17. TU-H-CAMPUS-JeP3-05: Adaptive Determination of Needle Sequence HDR Prostate Brachytherapy with Divergent Needle-By-Needle Delivery

    International Nuclear Information System (INIS)

    Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A; Denis de Senneville, B; Hautvast, G; Binnekamp, D

    2016-01-01

    Purpose: To develop a new method which adaptively determines the optimal needle insertion sequence for HDR prostate brachytherapy involving divergent needle-by-needle dose delivery by e.g. a robotic device. A needle insertion sequence is calculated at the beginning of the intervention and updated after each needle insertion with feedback on needle positioning errors. Methods: Needle positioning errors and anatomy changes may occur during HDR brachytherapy which can lead to errors in the delivered dose. A novel strategy was developed to calculate and update the needle sequence and the dose plan after each needle insertion with feedback on needle positioning errors. The dose plan optimization was performed by numerical simulations. The proposed needle sequence determination optimizes the final dose distribution based on the dose coverage impact of each needle. This impact is predicted stochastically by needle insertion simulations. HDR procedures were simulated with varying number of needle insertions (4 to 12) using 11 patient MR data-sets with PTV, prostate, urethra, bladder and rectum delineated. Needle positioning errors were modeled by random normally distributed angulation errors (standard deviation of 3 mm at the needle’s tip). The final dose parameters were compared in the situations where the needle with the largest vs. the smallest dose coverage impact was selected at each insertion. Results: Over all scenarios, the percentage of clinically acceptable final dose distribution improved when the needle selected had the largest dose coverage impact (91%) compared to the smallest (88%). The differences were larger for few (4 to 6) needle insertions (maximum difference scenario: 79% vs. 60%). The computation time of the needle sequence optimization was below 60s. Conclusion: A new adaptive needle sequence determination for HDR prostate brachytherapy was developed. Coupled to adaptive planning, the selection of the needle with the largest dose coverage impact

  18. Diagnostic radiology 1987

    International Nuclear Information System (INIS)

    Margulis, A.R.; Gooding, C.A.

    1987-01-01

    This is the latest version of the continuing education course on diagnostic radiology given yearly by the Department of Radiology at the University of California, San Francisco. The lectures are grouped into sections on gastrointestinal radiology, mammography, uroradiology, magnetic resonance, hepatobiliary radiology, pediatric radiology, ultrasound, interventional radiology, chest radiology, nuclear medicine, cardiovascular radiology, and skeletal radiology. Each section contains four to eight topics. Each of these consists of text that represents highlights in narrative form, selected illustrations, and a short bibliography. The presentation gives a general idea of what points were made in the lecture

  19. SU-E-T-459: Impact of Source Position and Traveling Time On HDR Skin Surface Applicator Dosimetry

    International Nuclear Information System (INIS)

    Jeong, J; Barker, C; Zaider, M; Cohen, G

    2015-01-01

    Purpose: Observed dosimetric discrepancy between measured and treatment planning system (TPS) predicted values, during applicator commissioning, were traced to source position uncertainty in the applicator. We quantify the dosimetric impact of this geometric uncertainty, and of the source traveling time inside the applicator, and propose corrections for clinical use. Methods: We measured the dose profiles from the Varian Leipzig-style (horizontal) HDR skin applicator, using EBT3 film, photon diode, and optically stimulated luminescence dosimeter (OSLD) and three different GammaMed HDR afterloders. The dose profiles and depth dose of each aperture were measured at several depths (up to about 10 mm, depending on the dosimeter). The measured dose profiles were compared with Acuros calculated profiles in BrachyVision TPS. For the impact of the source position, EBT3 film measurements were performed with applicator, facing-down and facing-up orientations. The dose with and without source traveling was measured with diode detector using HDR timer and electrometer timer, respectively. Results: Depth doses measured using the three dosimeters were in good agreement, but were consistently higher than the Acuros dose calculations. Measurements with the applicator facing-up were significantly lower than those in the facing-down position with maximum difference of about 18% at the surface, due to source sag inside the applicator. Based on the inverse-square law, the effective source sag was evaluated to be about 0.5 mm from the planned position. The additional dose from the source traveling was about 2.8% for 30 seconds with 10 Ci source, decreasing with increased dwelling time and decreased source activity. Conclusion: Due to the short source-to-surface distance of the applicator, the small source sag inside the applicator has significant dosimetric impact, which should be considered before the clinical use of the applicator. Investigation of the effect for other applicators

  20. Is there any place for LDR brachytherapy for head and neck carcinomas in HDR era?

    OpenAIRE

    Fijuth, Jacek

    2009-01-01

    In Poland, the classical LDR brachytherapy for head and neck carcinomas with Ir-192 wires or hairpins has completely disappeared some time ago after 30 years of successful clinical use. Can this technique be fully and safely replaced by HDR or PDR application? This option seems attractive because of new possibilities of 3D reconstruction and computer real-time treatment planning and optimization. However, in my opinion, long time is needed to get a clinical and scientific experience that has ...

  1. High dose rate (HDR) and low dose rate (LDR) interstitial irradiation (IRT) of the rat spinal cord

    International Nuclear Information System (INIS)

    Pop, Lucas A.M.; Plas, Mirjam van der; Skwarchuk, Mark W.; Hanssen, Alex E.J.; Kogel, Albert J. van der

    1997-01-01

    Purpose: To describe a newly developed technique to study radiation tolerance of rat spinal cord to continuous interstitial irradiation (IRT) at different dose rates. Material and methods: Two parallel catheters are inserted just laterally on each side of the vertebral bodies from the level of Th 10 to L 4 . These catheters are afterloaded with two 192 Ir wires of 4 cm length each (activity 1-2.3 mCi/cm) for the low dose rate (LDR) IRT or connected to the HDR micro-Selectron for the high dose rate (HDR) IRT. Spinal cord target volume is located at the level of Th 12 -L 2 . Due to the rapid dose fall-off around the implanted sources, a dose inhomogeneity across the spinal cord thickness is obtained in the dorso-ventral direction. Using the 100% reference dose (rate) at the ventral side of the spinal cord to prescribe the dose, experiments have been carried out to obtain complete dose response curves at average dose rates of 0.49, 0.96 and 120 Gy/h. Paralysis of the hind-legs after 5-6 months and histopathological examination of the spinal cord of each irradiated rat are used as experimental endpoints. Results: The histopathological damage seen after irradiation is clearly reflected the inhomogeneous dose distribution around the implanted catheters, with the damage predominantly located in the dorsal tract of the cord or dorsal roots. With each reduction in average dose rate, spinal cord radiation tolerance is significantly increased. When the dose is prescribed at the 100% reference dose rate, the ED 50 (induction of paresis in 50% of the animals) for the HDR-IRT is 17.3 Gy. If the average dose rate is reduced from 120 Gy/h to 0.96 or 0.49 Gy/h, a 2.9- or 4.7-fold increase in the ED 50 values to 50.3 Gy and 80.9 Gy is observed; for the dose prescribed at the 150% reference dose rate (dorsal side of cord) ED 50 values are 26.0, 75.5 and 121.4 Gy, respectively. Using different types of analysis and in dependence of the dose prescription and reference dose rate, the

  2. SU-F-T-11: Scintillator Based Quality Assurance Device for HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jozsef, G [New York University Medical Center, New York, NY (United States)

    2016-06-15

    Purpose: To build a test device for HDR afterloaders capable of checking source positions, times at positions and estimate the activity of the source. Methods: A catheter is taped on a plastic scintillation sheet. When a source travels through the catheter, the scintillator sheet lights up around the source. The sheet is monitored with a video camera, and records the movement of the light spot. The center of the spot on each image on the video provides the source location, and the time stamps of the images can provide the dwell time the source spend in each location. Finally, the brightness of the light spot is related to the activity of the source. A code was developed for noise removal, calibrate the scale of the image to centimeters, eliminate the distortion caused by the oblique view angle, identifying the boundaries of the light spot, transforming the image into binary and detect and calculate the source motion, positions and times. The images are much less noisy if the camera is shielded. That requires that the light spot is monitored in a mirror, rather than directly. The whole assembly is covered from external light and has a size of approximately 17×35×25cm (H×L×W) Results: A cheap camera in BW mode proved to be sufficient with a plastic scintillator sheet. The best images were resulted by a 3mm thick sheet with ZnS:Ag surface coating. The shielding of the camera decreased the noise, but could not eliminate it. A test run even in noisy condition resulted in approximately 1 mm and 1 sec difference from the planned positions and dwell times. Activity tests are in progress. Conclusion: The proposed method is feasible. It might simplify the monthly QA process of HDR Brachytherapy units.

  3. Dosimetric analysis at ICRU reference points in HDR-brachytherapy of cervical carcinoma.

    Science.gov (United States)

    Eich, H T; Haverkamp, U; Micke, O; Prott, F J; Müller, R P

    2000-01-01

    In vivo dosimetry in bladder and rectum as well as determining doses on suggested reference points following the ICRU report 38 contribute to quality assurance in HDR-brachytherapy of cervical carcinoma, especially to minimize side effects. In order to gain information regarding the radiation exposure at ICRU reference points in rectum, bladder, ureter and regional lymph nodes those were calculated (digitalisation) by means of orthogonal radiographs of 11 applications in patients with cervical carcinoma, who received primary radiotherapy. In addition, the doses at the ICRU rectum reference point was compared to the results of in vivo measurements in the rectum. The in vivo measurements were by factor 1.5 below the doses determined for the ICRU rectum reference point (4.05 +/- 0.68 Gy versus 6.11 +/- 1.63 Gy). Reasons for this were: calibration errors, non-orthogonal radiographs, movement of applicator and probe in the time span between X-ray and application, missing connection of probe and anterior rectal wall. The standard deviation of calculations at ICRU reference points was on average +/- 30%. Possible reasons for the relatively large standard deviation were difficulties in defining the points, identifying them on radiographs and the different locations of the applicators. Although 3 D CT, US or MR based treatment planning using dose volume histogram analysis is more and more established, this simple procedure of marking and digitising the ICRU reference points lengthened treatment planning only by 5 to 10 minutes. The advantages of in vivo dosimetry are easy practicability and the possibility to determine rectum doses during radiation. The advantages of computer-aided planning at ICRU reference points are that calculations are available before radiation and that they can still be taken into account for treatment planning. Both methods should be applied in HDR-brachytherapy of cervical carcinoma.

  4. Preliminary results of a phase I/II study of HDR brachytherapy alone for T1/T2 breast cancer

    International Nuclear Information System (INIS)

    Wazer, David E.; Berle, Lisa; Graham, Roger; Chung, Maureen; Rothschild, Janice; Graves, Theresa; Cady, Blake; Ulin, Kenneth; Ruthazer, Robin; DiPetrillo, Thomas A.

    2002-01-01

    Purpose: To investigate the feasibility, toxicity, cosmetic outcome, and local control of high-dose-rate (HDR) brachytherapy alone without whole breast external beam irradiation for early-stage breast carcinoma. Methods and Materials: Between June 1997 and August 1999, 32 women diagnosed with a total of 33 AJCC Stage I/II breast carcinomas underwent surgical breast excision and postoperative irradiation using HDR brachytherapy interstitial implantation as part of a multi-institutional clinical Phase I/II protocol. Eligible patients included those with T1, T2, N0, N1 (≤3 nodes positive), and M0 tumors of nonlobular histologic features with negative surgical margins, no extracapsular lymph node extension, and a negative postexcision mammogram. Brachytherapy catheters were placed at the initial excision, reexcision, or either sentinel or full-axillary sampling. Direct visualization, surgical clips, and ultrasound and/or CT scan assisted in the delineation of the target volume, defined as the excision cavity plus a 2-cm margin. High-activity 192 Ir (3-10 Ci) was used to deliver 340 cGy/fraction, 2 fractions/d, for 5 consecutive days, to a total dose of 34 Gy to the target volume. Source position and dwell times were calculated using standard volume optimization techniques. Results: The median follow-up of all patients was 33 months, and the mean patient age was 63 years. The mean tumor size was 1.3 cm, and 55% had an extensive intraductal component. Three patients had positive axillary nodes. Two patients experienced moderate perioperative pain that required narcotic analgesics. No peri- or postoperative infections occurred. No wound healing problems and no significant skin reactions related to the implant developed. The Radiation Therapy Oncology Group late radiation morbidity scoring scheme was applied to the entire 33-case cohort. In the assessment of the skin, 30 cases were Grade 0-1 and 3 cases were Grade 2. Subcutaneous toxicity was scored as 11 patients with

  5. Radiology fundamentals

    CERN Document Server

    Singh, Harjit

    2011-01-01

    ""Radiology Fundamentals"" is a concise introduction to the dynamic field of radiology for medical students, non-radiology house staff, physician assistants, nurse practitioners, radiology assistants, and other allied health professionals. The goal of the book is to provide readers with general examples and brief discussions of basic radiographic principles and to serve as a curriculum guide, supplementing a radiology education and providing a solid foundation for further learning. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imag

  6. Poul Erik Andersen's radiological work on Osteochondrodysplasias and interventional radiology

    DEFF Research Database (Denmark)

    Andersen, Poul Erik

    2011-01-01

    Hospital. His significant experience and extensive scientific work has led to many posts in the Danish Society of Interventional Radiology, the European Society of Radiology and the Cardiovascular and Interventional Radiological Society of Europe, where he is a fellow and has passed the European Board...... of Interventional Radiology - The European qualification in Interventional Radiology....

  7. Sampling on radiological protection training in diagnostic radiology

    International Nuclear Information System (INIS)

    Gaona, E.

    2001-01-01

    Radiological security aspects were evaluated in radiology departments from Mexico City. The study was carried out in two stages, the first one evaluated 40 departments just before the implementation of the new Official Mexican Standards related to Radiological Security and Quality Control in Radiology; in the second stage 33 departments were evaluated 2 years after those standards were implanted, showing a favorable impact of the training programs for the type of answers obtained [es

  8. Biological effective dose evaluation in gynaecological brachytherapy: LDR and HDR treatments, dependence on radiobiological parameters, and treatment optimisation.

    Science.gov (United States)

    Bianchi, C; Botta, F; Conte, L; Vanoli, P; Cerizza, L

    2008-10-01

    This study was undertaken to compare the biological efficacy of different high-dose-rate (HDR) and low-dose-rate (LDR) treatments of gynaecological lesions, to identify the causes of possible nonuniformity and to optimise treatment through customised calculation. The study considered 110 patients treated between 2001 and 2006 with external beam radiation therapy and/or brachytherapy with either LDR (afterloader Selectron, (137)Cs) or HDR (afterloader microSelectron Classic, (192)Ir). The treatments were compared in terms of biologically effective dose (BED) to the tumour and to the rectum (linear-quadratic model) by using statistical tests for comparisons between independent samples. The difference between the two treatments was statistically significant in one case only. However, within each technique, we identified considerable nonuniformity in therapeutic efficacy due to differences in fractionation schemes and overall treatment time. To solve this problem, we created a Microsoft Excel spreadsheet allowing calculation of the optimal treatment for each patient: best efficacy (BED(tumour)) without exceeding toxicity threshold (BED(rectum)). The efficacy of a treatment may vary as a result of several factors. Customised radiobiological evaluation is a useful adjunct to clinical evaluation in planning equivalent treatments that satisfy all dosimetric constraints.

  9. SU-F-T-37: Dosimetric Evaluation of Planned Versus Decay Corrected Treatment Plans for the Treatment of Tandem-Based Cervical HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, M [Texas Oncology, PA, Fort Worth, TX (United States); Shobhit University, Meerut, Uttar Pradesh (India); Manjhi, J; Rai, D [Shobhit University, Meerut, Uttar Pradesh (India); Kehwar, T [Pinnacle Health Cancer Center, Mechanicsburg, PA (United States); Barker, J; Heintz, B; Shide, K [Texas Oncology, PA, Fort Worth, TX (United States)

    2016-06-15

    Purpose: This study evaluated dosimetric parameters for actual treatment plans versus decay corrected treatment plans for cervical HDR brachytherapy. Methods: 125 plans of 25 patients, who received 5 fractions of HDR brachytherapy, were evaluated in this study. Dose was prescribed to point A (ICRU-38) and High risk clinical tumor volume (HR-CTV) and organs at risk (OAR) were, retrospectively, delineated on original CT images by treating physician. First HDR plan was considered as reference plan and decay correction was applied to calculate treatment time for subsequent fractions, and was applied, retrospectively, to determine point A, HR-CTV D90, and rectum and bladder doses. Results: The differences between mean point A reference doses and the point A doses of the plans computed using decay times were found to be 1.05%±0.74% (−2.26% to 3.26%) for second fraction; −0.25%±0.84% (−3.03% to 3.29%) for third fraction; 0.04%±0.70% (−2.68% to 2.56%) for fourth fraction and 0.30%±0.81% (−3.93% to 2.67%) for fifth fraction. Overall mean point A dose difference, for all fractions, was 0.29%±0.38% (within ± 5%). Mean rectum and bladder dose differences were calculated to be −3.46%±0.12% and −2.47%±0.09%, for points, respectively, and −1.72%±0.09% and −0.96%±0.06%, for D2cc, respectively. HR-CTV D90 mean dose difference was found to be −1.67% ± 0.11%. There was no statistically significant difference between the reference planned point A doses and that calculated using decay time to the subsequent fractions (p<0.05). Conclusion: This study reveals that a decay corrected treatment will provide comparable dosimetric results and can be utilized for subsequent fractions of cervical HDR brachytherapy instead of actual treatment planning. This approach will increase efficiency, decrease workload, reduce patient observation time between applicator insertion and treatment delivery. This would be particularly useful for institutions with limited

  10. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    Kovacs, Gyoergy; Hoskin, Peter

    2013-01-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  11. Ir-192 HDR transit dose and radial dose function determination using alanine/EPR dosimetry

    International Nuclear Information System (INIS)

    Calcina, Carmen S Guzman; Almeida, Adelaide de; Rocha, Jose R Oliveira; Abrego, Felipe Chen; Baffa, Oswaldo

    2005-01-01

    Source positioning close to the tumour in high dose rate (HDR) brachytherapy is not instantaneous. An increment of dose will be delivered during the movement of the source in the trajectory to its static position. This increment is the transit dose, often not taken into account in brachytherapeutic treatment planning. The transit dose depends on the prescribed dose, number of treatment fractions, velocity and activity of the source. Combining all these factors, the transit dose can be 5% higher than the prescribed absorbed dose value (Sang-Hyun and Muller-Runkel, 1994 Phys. Med. Biol. 39 1181-8, Nath et al 1995 Med. Phys. 22 209-34). However, it cannot exceed this percentage (Nath et al 1995). In this work, we use the alanine-EPR (electron paramagnetic resonance) dosimetric system using analysis of the first derivative of the signal. The transit dose was evaluated for an HDR system and is consistent with that already presented for TLD dosimeters (Bastin et al 1993 Int. J. Radiat. Oncol. Biol. Phys. 26 695-702). Also using the same dosimetric system, the radial dose function, used to evaluate the geometric dose degradation around the source, was determined and its behaviour agrees better with those obtained by Monte Carlo simulations (Nath et al 1995, Williamson and Nath 1991 Med. Phys. 18 434-48, Ballester et al 1997 Med. Phys. 24 1221-8, Ballester et al 2001 Phys. Med. Biol. 46 N79-90) than with TLD measurements (Nath et al 1990 Med. Phys. 17 1032-40)

  12. Chronicle of pediatric radiology

    International Nuclear Information System (INIS)

    Benz-Bohm, Gabriele; Richter, Ernst

    2012-01-01

    The chronicle of pediatric radiology covers the following issues: Development of pediatric radiology in Germany (BRD, DDR, pediatric radiological accommodations); development of pediatric radiology in the Netherlands (chronology and pediatric radiological accommodations); development of pediatric radiology in Austria (chronology and pediatric radiological accommodations); development of pediatric radiology in Switzerland (chronology and pediatric radiological accommodations).

  13. Imaging and radiology

    Science.gov (United States)

    Interventional radiology; Diagnostic radiology; X-ray imaging ... DIAGNOSTIC RADIOLOGY Diagnostic radiology helps health care professionals see structures inside your body. Doctors that specialize in the interpretation ...

  14. Is there any place for LDR brachytherapy for head and neck carcinomas in HDR era?

    Science.gov (United States)

    Fijuth, Jacek

    2009-03-01

    In Poland, the classical LDR brachytherapy for head and neck carcinomas with Ir-192 wires or hairpins has completely disappeared some time ago after 30 years of successful clinical use. Can this technique be fully and safely replaced by HDR or PDR application? This option seems attractive because of new possibilities of 3D reconstruction and computer real-time treatment planning and optimization. However, in my opinion, long time is needed to get a clinical and scientific experience that has been accumulated for decades with the use of LDR technique.

  15. Radiological Control Manual

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records.

  16. Radiological Control Manual

    International Nuclear Information System (INIS)

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records

  17. Radiological English

    Energy Technology Data Exchange (ETDEWEB)

    Ribes, R. [Hospital Reina Sofia, Cordoba (Spain). Servicio de Radiologia; Ros, P.R. [Harvard Medical School, Boston, MA (United States). Div. of Radiology

    2007-07-01

    The book is an introductory book to radiological English on the basis that there are a lot of radiologists, radiology residents, radiology nurses, radiology students, and radiographers worldwide whose English level is indeterminate because their reading skills are much higher than their fluency. It is intended to help those health care professionals who need English for their work but do not speak English on a day-to-day basis. (orig.)

  18. Radiological English

    International Nuclear Information System (INIS)

    Ribes, R.; Ros, P.R.

    2007-01-01

    The book is an introductory book to radiological English on the basis that there are a lot of radiologists, radiology residents, radiology nurses, radiology students, and radiographers worldwide whose English level is indeterminate because their reading skills are much higher than their fluency. It is intended to help those health care professionals who need English for their work but do not speak English on a day-to-day basis. (orig.)

  19. Handbook of radiologic procedures

    International Nuclear Information System (INIS)

    Hedgcock, M.

    1986-01-01

    This book is organized around radiologic procedures with each discussed from the points of view of: indications, contraindications, materials, method of procedures and complications. Covered in this book are: emergency radiology chest radiology, bone radiology, gastrointestinal radiology, GU radiology, pediatric radiology, computerized tomography, neuroradiology, visceral and peripheral angiography, cardiovascular radiology, nuclear medicine, lymphangiography, and mammography

  20. Heissdampfreaktor (HDR) steel-containment-vessel and floodwater-storage-tank structural-dynamics tests

    International Nuclear Information System (INIS)

    Arendts, J.G.

    1982-01-01

    Inertance (vibration) testing of two significant vessels at the Heissdampfreaktor (HDR) facility, located near Kahl, West Germany, was recently completed. Transfer functions were obtained for determination of the modal properties (frequencies, mode shapes and damping) of the vessels using two different test methods for comparative purposes. One of the vessels tested was the steel containment vessel (SCV). The SCV is approximately 180 feet high and 65 feet in diameter with a 1.2-inch wall thickness. The other vessel, called the floodwater storage tank (FWST), is a vertically standing vessel approximately 40 feet high and 10 feet in diameter with a 1/2-inch wall thickness. The FWST support skirt is square (in plan views) with its corners intersecting the ellipsoidal bottom head near the knuckle region

  1. Comparison of leak opening and leak rate calculations to HDR experimental results

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1993-01-01

    During the last years a number of calculations of leak opening and leak rate for through cracks in piping components have been performed. Analyses are pre- or mostly post-calculations to experiments performed at the HDR facility under PWR operating conditions. Piping components under consideration were small diameter straight pipes with circumferential cracks, pipe bends with longitudinal or circumferential cracks and pipe branches with weldment cracks. The components were loaded by internal pressure and opening as well as closing bending moment. The finite element method and two-phase flow leak rate programs were used for the calculations. Results of the analyses are presented as J-integral values, crack opening displacements and areas and leak rates as well as comparisons to the experimental results

  2. RSVP radiology

    International Nuclear Information System (INIS)

    Kirks, D.R.; Chaffee, D.J.

    1990-01-01

    This paper develops a relative scale of value for pediatric radiology (RSVPR). Neither the HCFA/ACA Relative Value Scale nor the Workload Measurement System developed by Health and Welfare Canada specifically addressed pediatric radiologic examinations. Technical and professional charges for examinations at Children's Hospital Medical Center were reviewed and compared with time and cost analysis. A scale was developed with chest radiography (PA and lateral views) assigned a value of 1. After review by pediatric radiologic technologists, radiologic administrators, pediatric radiologists, and chairs of departments of children's hospitals, this proposed scale was modified to reflect more accurately relative value components of pediatric radiologic and imaging examinations

  3. Radiological anatomy - evaluation of integrative education in radiology.

    Science.gov (United States)

    Dettmer, S; Schmiedl, A; Meyer, S; Giesemann, A; Pabst, R; Weidemann, J; Wacker, F K; Kirchhoff, T

    2013-09-01

    Evaluation and analysis of the integrative course "Radiological Anatomy" established since 2007 at the Medical School Hannover (MHH) in comparison with conventional education. Anatomy and radiology are usually taught separately with a considerable time lag. Interdisciplinary teaching of these associated subjects seems logical for several reasons. Therefore, the integrative course "Radiological Anatomy" was established in the second year of medical education, combining these two closely related subjects. This interdisciplinary course was retrospectively evaluated by consideration of a student questionnaire and staff observations. The advantages and disadvantages of integrative teaching in medical education are discussed. The course ratings were excellent (median 1; mean 1.3 on a scale of 1 to 6). This is significantly (p radiology increased during the course (88 %). According to the students' suggestions the course was enhanced by a visitation in the Department of Radiology and the additional topic central nervous system. Integrative teaching of anatomy and radiology was well received by the students. Both, anatomical and radiological comprehension and the motivation to learn were improved. However, it should be considered, that the amount of work and time required by the teaching staff is considerably increased compared to traditional teaching. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Analysis of the Radiology Reports from Radiology Clinics

    International Nuclear Information System (INIS)

    Kim, Eun Jin; Kwack, Kyu Sung; Cho, Jae Hyun; Jang, Eun Ho

    2009-01-01

    The purpose of this study was to investigate the form and content of the radiology reports from radiology clinics in Korea. One hundred and sixty six radiology reports from 49 radiology clinics were collected, and these reports were referred to the academic tertiary medical center from March 2008 to February 2009. These included reports for CT (n = 18), MRI (n = 146) and examinations not specified (n = 2). Each report was evaluated for the presence of required contents (demographics, technical information, findings, conclusion, the name, license number and signature of the radiologist and the referring facility). These requirements were based on the guideline of the American College of Radiology and the previous research. The name of the patient, the gender, the body part, the type of examination, the time of examination and the conclusion, the name of the radiologist and the name of facility were well recorded in over 90% of the radiology reports. However, the identification number of the patient, the referring facility, the referring physician, the use of contrast material, the clinical information, the time of dictation, the signature of the radiologist and the license number of the radiologist were poorly recorded (less than 50%). The optimal format of a radiology report should be established for reliable and valid communication with clinicians

  5. Radiology research in mainland China in the past 10 years: a survey of original articles published in Radiology and European Radiology.

    Science.gov (United States)

    Zhang, Long Jiang; Wang, Yun Fei; Yang, Zhen Lu; Schoepf, U Joseph; Xu, Jiaqian; Lu, Guang Ming; Li, Enzhong

    2017-10-01

    To evaluate the features and trends of Radiology research in Mainland China through bibliometric analysis of the original articles published in Radiology and European Radiology (ER) between 2006 and 2015. We reviewed the original articles published in Radiology and ER between 2006 and 2015. The following information was abstracted: imaging subspecialty, imaging technique(s) used, research type, sample size, study design, statistical analysis, study results, funding declarations, international collaborations, number of authors, department and province of the first author. All variables were examined longitudinally over time. Radiology research in Mainland China saw a substantial increase in original research articles published, especially in the last 5 years (P Radiology research, neuroradiology, vascular/interventional Radiology, and abdominal Radiology were the most productive fields; MR imaging was the most used modality, and a distinct geographic provenience was observed for articles published in Radiology and ER. Radiology research in Mainland China has seen substantial growth in the past 5 years with neuroradiology, vascular/interventional Radiology, and abdominal Radiology as the most productive fields. MR imaging is the most used modality. Article provenience shows a distinct geographical pattern. • Radiology research in Mainland China saw a substantial increase. • Neuroradiology, vascular/interventional Radiology, and abdominal Radiology are the most productive fields. • MRI is the most used modality in Mainland China's Radiology research. • Guangdong, Shanghai, and Beijing are the most productive provinces.

  6. Introduction of radiological protection; Pengenalan kepada perlindungan radiologi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-12-31

    The chapter briefly discussed the following subjects: basic principles of radiological protection , dose limit which was suggested, stochastic and nonstochastic effects, equivalent dose and alternative of it`s calculation, limit for the publics, ICRP (International Commission for Radiological Protection) recommendations, and the principles of radiological protection. Dangerous radiation sources also briefly summarized i.e. x-ray generators, reactor nucleus.

  7. 13. status report of the project HDR safety program of Kernforschungszentrum Karlsruhe. Working report 05.46/89

    International Nuclear Information System (INIS)

    Katzenmeier, G.

    1989-01-01

    The programme phase III, which extends to the end of 1991, is divided into the part projects containment behaviour in extreme accidents, long-term damage and monitoring the components in operation, behaviour of damaged components in dynamic accidents and large fires of actual materials. The main aims, state of the HDR safety programme, main points of the programme for 1990 and 8 technical reports on phase II and III are documented. There is a survey of costs. (DG) [de

  8. Accurate assessment of the distortions produced by the transit dose in HDR brachytherapy

    International Nuclear Information System (INIS)

    Nani, E.K.; Kyere, A.W.K.; Tetteh, K.

    2001-01-01

    Current polynomial methods used in the modelling of the dose distributions in HDR brachytherapy have been reformulated to improve accuracy. An example is provided to show the effects of the transit dose on the output. The transit dose, which is neglected by current computer software for calculating doses, can result in significant dosimetric errors. These additional unrecognised doses imply over-dosing and distortions in the dose distributions within the irradiated volume. Assessment of dose to critical and radiosensitive organs is therefore inaccurate. These could increase late tissue complications as predicted by the Linear Quadratic Model. Our model works very well for straight catheters and is highly recommended for the evaluation of the transit dose around such catheters. (author)

  9. Radiology

    International Nuclear Information System (INIS)

    Edholm, P.R.

    1990-01-01

    This is a report describing diagnostic techniques used in radiology. It describes the equipment necessary for, and the operation of a radiological department. Also is described the standard methods used in radiodiagnosis. (K.A.E.)

  10. A national survey of HDR source knowledge among practicing radiation oncologists and residents: Establishing a willingness-to-pay threshold for cobalt-60 usage.

    Science.gov (United States)

    Mailhot Vega, Raymond; Talcott, Wesley; Ishaq, Omar; Cohen, Patrice; Small, Christina J; Duckworth, Tamara; Sarria Bardales, Gustavo; Perez, Carmen A; Schiff, Peter B; Small, William; Harkenrider, Matthew M

    Ir-192 is the predominant source for high-dose-rate (HDR) brachytherapy in United States markets. Co-60, with longer half-life and fewer source exchanges, has piloted abroad with comparable clinical dosimetry but increased shielding requirements. We sought to identify practitioner knowledge of Co-60 and establish acceptable willingness-to-pay (WTP) thresholds for additional shielding requirements for use in future cost-benefit analysis. A nationwide survey of U.S. radiation oncologists was conducted from June to July 2015, assessing knowledge of HDR sources, brachytherapy unit shielding, and factors that may influence source-selection decision-making. Self-identified decision makers in radiotherapy equipment purchase and acquisition were asked their WTP on shielding should a more cost-effective source become available. Four hundred forty surveys were completed and included. Forty-four percent were ABS members. Twenty percent of respondents identified Co-60 as an HDR source. Respondents who identified Co-60 were significantly more likely to be ABS members, have attended a national brachytherapy conference, and be involved in brachytherapy selection. Sixty-six percent of self-identified decision makers stated that their facility would switch to a more cost-effective source than Ir-192, if available. Cost and experience were the most common reasons provided for not switching. The most common WTP value selected by respondents was decision makers to establish WTP for shielding costs that source change to Co-60 may require. These results will be used to establish WTP threshold for future cost-benefit analysis. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. The influence of the dwell time deviation constraint (DTDC) parameter on dosimetry with IPSA optimisation for HDR prostate brachytherapy

    International Nuclear Information System (INIS)

    Smith, Ryan L.; Millar, Jeremy L.; Panettieri, Vanessa; Mason, Natasha; Lancaster, Craig; Francih, Rick D.

    2015-01-01

    To investigate how the dwell time deviation constraint (DTDC) parameter, applied to inverse planning by simulated annealing (IPSA) optimisation limits large dwell times from occurring in each catheter and to characterise the effect on the resulting dosimetry for prostate high dose rate (HDR) brachytherapy treatment plans. An unconstrained IPSA optimised treatment plan, using the Oncentra Brachytherapy treatment planning system (version 4.3, Nucletron an Elekta company, Elekta AB, Stockholm, Sweden), was generated for 20 consecutive HDR prostate brachytherapy patients, with the DTDC set to zero. Successive constrained optimisation plans were also created for each patient by increasing the DTDC parameter by 0.2, up to a maximum value of 1.0. We defined a “plan modulation index”, to characterise the change of dwell time modulation as the DTDC parameter was increased. We calculated the dose volume histogram indices for the PTV (D90, V100, V150, V200%) and urethra (D10%) to characterise the effect on the resulting dosimetry. The average PTV D90% decreases as the DTDC is applied, on average by only 1.5 %, for a DTDC = 0.4. The measures of high dose regions in the PTV, V150 and V200%, increase on average by less than 5 and 2 % respectively. The net effect of DTDC on the modulation of dwell times has been characterised by the introduction of the plan modulation index. DTDC applied during IPSA optimisation of HDR prostate brachytherapy plans reduce the occurrence of large isolated dwell times within individual catheters. The mechanism by which DTDC works has been described and its effect on the modulation of dwell times has been characterised. The authors recommend using a DTDC parameter no greater than 0.4 to obtain a plan with dwell time modulation comparable to a geometric optimised plan. This yielded on average a 1.5 % decrease in PTV coverage and an acceptable increase in V150%, without compromising the urethral dose.

  12. Radiology research in mainland China in the past 10 years: a survey of original articles published in Radiology and European Radiology

    International Nuclear Information System (INIS)

    Zhang, Long Jiang; Wang, Yun Fei; Yang, Zhen Lu; Lu, Guang Ming; Schoepf, U.J.; Xu, Jiaqian; Li, Enzhong

    2017-01-01

    To evaluate the features and trends of Radiology research in Mainland China through bibliometric analysis of the original articles published in Radiology and European Radiology (ER) between 2006 and 2015. We reviewed the original articles published in Radiology and ER between 2006 and 2015. The following information was abstracted: imaging subspecialty, imaging technique(s) used, research type, sample size, study design, statistical analysis, study results, funding declarations, international collaborations, number of authors, department and province of the first author. All variables were examined longitudinally over time. Radiology research in Mainland China saw a substantial increase in original research articles published, especially in the last 5 years (P < 0.001). Within Mainland China's Radiology research, neuroradiology, vascular/interventional Radiology, and abdominal Radiology were the most productive fields; MR imaging was the most used modality, and a distinct geographic provenience was observed for articles published in Radiology and ER. Radiology research in Mainland China has seen substantial growth in the past 5 years with neuroradiology, vascular/interventional Radiology, and abdominal Radiology as the most productive fields. MR imaging is the most used modality. Article provenience shows a distinct geographical pattern. (orig.)

  13. Radiology research in mainland China in the past 10 years: a survey of original articles published in Radiology and European Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang; Wang, Yun Fei; Yang, Zhen Lu; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Xu, Jiaqian [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Li, Enzhong [National Natural Science Foundation of China, Department of Medical Science, Beijing (China)

    2017-10-15

    To evaluate the features and trends of Radiology research in Mainland China through bibliometric analysis of the original articles published in Radiology and European Radiology (ER) between 2006 and 2015. We reviewed the original articles published in Radiology and ER between 2006 and 2015. The following information was abstracted: imaging subspecialty, imaging technique(s) used, research type, sample size, study design, statistical analysis, study results, funding declarations, international collaborations, number of authors, department and province of the first author. All variables were examined longitudinally over time. Radiology research in Mainland China saw a substantial increase in original research articles published, especially in the last 5 years (P < 0.001). Within Mainland China's Radiology research, neuroradiology, vascular/interventional Radiology, and abdominal Radiology were the most productive fields; MR imaging was the most used modality, and a distinct geographic provenience was observed for articles published in Radiology and ER. Radiology research in Mainland China has seen substantial growth in the past 5 years with neuroradiology, vascular/interventional Radiology, and abdominal Radiology as the most productive fields. MR imaging is the most used modality. Article provenience shows a distinct geographical pattern. (orig.)

  14. NPIP: A skew line needle configuration optimization system for HDR brachytherapy

    International Nuclear Information System (INIS)

    Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtürk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean

    2012-01-01

    Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, δ. The candidate needle set consisted of 5000 needles, and a range of δ values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of δ values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer

  15. Radiological protection in interventional radiology

    International Nuclear Information System (INIS)

    Padovani, R.

    2001-01-01

    Interventional radiology (IR) reduces the need for many traditional interventions, particularly surgery, so reducing the discomfort and risk for patients compared with traditional systems. IR procedures are frequently performed by non-radiologist physicians, often without the proper radiological equipment and sufficient knowledge of radiation protection. Levels of doses to patients and staff in IR vary enormously. A poor correlation exists between patient and staff dose, and large variations of dose are reported for the same procedure. The occurrence of deterministic effects in patients is another peculiar aspect of IR owing to the potentially high skin doses of some procedures. The paper reviews the use of IR and the radiological protection of patients and staff, and examines the need for new standards for IR equipment and the training of personnel. (author)

  16. General Employee Radiological Training and Radiological Worker Training: Program management manual

    International Nuclear Information System (INIS)

    1992-10-01

    This manual defines and describes the DOE General Employee Radiological Training (GERT) and Radiological Worker I and II (RW I and II) Training programs. It includes material development requirements, standards and policies, and program administration. This manual applies to General Employee Radiological Training and Radiological Worker Training at all DOE contractor sites. The training materials of both GERT and RW I and II training reflect the requirements identified in the DOE Radiological Control Manual and DOE Order 5480.11. The training programs represent the minimum requirement for the standardized core materials. Each contractor shall implement the program in its entirety and may augment the standardized core materials to increase the general employee and radiological worker level of competency

  17. Laboratory implantation for well type ionization chambers calibration

    International Nuclear Information System (INIS)

    Vianello, E.A.; Dias, D.J.; Almeida, C.E. de

    1998-01-01

    The Radiological Science Laboratory is implanting a service for calibration of well type chambers by IAEA training program. The kerma rate in the air (mu Gy/h) of the linear Cs-137 reference source CDCS-J4 have been determined using a well type chamber Standard Imaging HDR-1000 model, which have been calibrated at Secondary Standard Laboratory Calibration of IAEA, whereas two HDR-1000 Plus chambers were calibrated too, following the same standards. The results were compared with Wisconsin University calibration certification and has demonstrated that well type ionization chamber calibration can be used in brachytherapy for several kinds of radionuclides. (Author)

  18. Laboratory implantation for well type ionization chambers calibration; Implantacao de um laboratorio para calibracao de camaras de ionizacao tipo poco

    Energy Technology Data Exchange (ETDEWEB)

    Vianello, E.A.; Dias, D.J.; Almeida, C.E. de [Laboratorio de Ciencias Radiologicas- LCR- DBB (UERJ). R. Sao Francisco Xavier, 524- Pav. HLC, sala 136 terreo- CEP 20.550-013. Rio de Janeiro (Brazil)

    1998-12-31

    The Radiological Science Laboratory is implanting a service for calibration of well type chambers by IAEA training program. The kerma rate in the air (mu Gy/h) of the linear Cs-137 reference source CDCS-J4 have been determined using a well type chamber Standard Imaging HDR-1000 model, which have been calibrated at Secondary Standard Laboratory Calibration of IAEA, whereas two HDR-1000 Plus chambers were calibrated too, following the same standards. The results were compared with Wisconsin University calibration certification and has demonstrated that well type ionization chamber calibration can be used in brachytherapy for several kinds of radionuclides. (Author)

  19. Exclusive radiation therapy of endometrial carcinoma using HDR Co-60 and Cf-252 sources

    International Nuclear Information System (INIS)

    Inciura, A.; Janulionis, E.; Atkocius, V.

    2000-01-01

    Although the main treatment of endometrial cancer is surgery, the gross spread of carcinoma in pelvis, elderly age of the patients and serious therapeutical diseases do not allow to operate 20% of the patients. For these patients only radical treatment decision is the combined radiation therapy. However, using various modalities of combined radiotherapy, the treatment results are not satisfying: only 52% of patients survive 5 years. There was implemented a new method of combined radiotherapy, using a three-channel applicator with two-positional locating of HDR Co-60 radioactive sources (group I). A new method of brachytherapy for endometrial carcinoma using a HDR Cf 252 sources (group II) was implemented too. For group I the medium total dose of the point A was 77.6 Gy, point I - 69.6 Gy. point 2 - 84.2 Gy, point B - 52.6 Gy, For group II the medium total dose the points A, 3 and 4 was 50 iGy. For group I 1 year overaII survival rate was 85%, 3 year - 73%. The 3 year survival rate for stage I was 79%, for stage II - 89%, for stage III - 33%. 3 year survival for highly virulent tumours - 56% and for low virulent (adenocarcinoma) - 82% was statistically different. The loss of tumour differentiation correlated with the worse prognosis: 3 year survival for G1 and G2 tumours was 92%, for G3 - 45%. Low hemoglobin level was also associated with low survival rate: 2 year survival for Hb≥120g/l was 85% and Hb<120g/l - 23%. 1 year survival rate was 87%, 3 year - 66%, 5 year - 58% for group II, treated with Cf-252. Radiation complications occurred for 13.8% of the patients for group I and 6.2% for group II. Good survival rates and a small number of complications sufficiently proofed treatment method. (author)

  20. 3D workflow for HDR image capture of projection systems and objects for CAVE virtual environments authoring with wireless touch-sensitive devices

    Science.gov (United States)

    Prusten, Mark J.; McIntyre, Michelle; Landis, Marvin

    2006-02-01

    A 3D workflow pipeline is presented for High Dynamic Range (HDR) image capture of projected scenes or objects for presentation in CAVE virtual environments. The methods of HDR digital photography of environments vs. objects are reviewed. Samples of both types of virtual authoring being the actual CAVE environment and a sculpture are shown. A series of software tools are incorporated into a pipeline called CAVEPIPE, allowing for high-resolution objects and scenes to be composited together in natural illumination environments [1] and presented in our CAVE virtual reality environment. We also present a way to enhance the user interface for CAVE environments. The traditional methods of controlling the navigation through virtual environments include: glove, HUD's and 3D mouse devices. By integrating a wireless network that includes both WiFi (IEEE 802.11b/g) and Bluetooth (IEEE 802.15.1) protocols the non-graphical input control device can be eliminated. Therefore wireless devices can be added that would include: PDA's, Smart Phones, TabletPC's, Portable Gaming consoles, and PocketPC's.

  1. Video Enhancement and Dynamic Range Control of HDR Sequences for Automotive Applications

    Directory of Open Access Journals (Sweden)

    Giovanni Ramponi

    2007-01-01

    Full Text Available CMOS video cameras with high dynamic range (HDR output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorithms have been proposed in the literature to reduce the dynamic range of still pictures. Anyway, extending the available methods to video is not straightforward, due to the peculiar nature of video data. We propose an algorithm for both reducing the dynamic range of video sequences and enhancing its appearance, thus improving visual quality and reducing temporal artifacts. We also provide an optimized version of our algorithm for a viable hardware implementation on an FPGA. The feasibility of this implementation is demonstrated by means of a case study.

  2. Preliminary results of intersticial HDR brachytherapy in association with conservative surgery for soft tissue sarcomas

    International Nuclear Information System (INIS)

    Pellizzon, A.C.A; Ferrigno, R.; Trippe, N.; Novaes, P.; Salvajoli, J.V.; Fogareli, R.; Maja, M.A.C.; Baraldi, H.

    1996-01-01

    From january 1994 to january 1995 seven patients were treated with conservative surgery in association to postoperative HDR brachytherapy through Micro-Selectron HDR. Four patients were male and three female, the ages ranged from 20 to 60 years old and the main site of the tumor were at the extremities and just one had a perineal lesion. The follow up ranged from 4 to 24 months. Most of the implants were done through single plane technic. Definition of the treatment volume was based on CT scans and metallic clips inserted during the surgery. The prescribed dose was at 10mm from the implant plane. The patient with perineal lesion had a volumetric implant and the dose prescription was based on Paris System, in which the total volume of the tumor bed must be included in a 85% isodose curve. The number of catheters used ranged from 6 to 14 and the active length from 20 to 150mm, placed intraoperatively. The volumetric implant was performed through perineal template to guide the needles in number of nine and an active length of 60mm. The prescribed dose ranged from 20 to 25Gy when associated with EBRT and 30 to 35Gy when brachytherapy alone was used. Results: All patients had local control. Acute complications were observed only in the skin, limited to mild erytema and dry descanation. Conclusions: Although the number of the patients is small, this procedure has been shown to be effective in local control when associated to conservative surgery, can be easily and safely done and gives the possibilities of dose optimization

  3. Feasibility and early results of interstitial intensity-modulated HDR/PDR brachytherapy (IMBT) with/without complementary external-beam radiotherapy and extended surgery in recurrent pelvic colorectal cancer

    International Nuclear Information System (INIS)

    Tepel, J.; Bokelmann, F.; Faendrich, F.; Kremer, B.; Schmid, A.; Kovacs, G.; University Hospital of Schleswig-Holstein, Kiel

    2005-01-01

    Background: A new multimodality treatment concept consisting of extended resection and postoperative fractionated intensity-modulated interstitial brachytherapy (IMBT) was introduced for pelvic recurrence of colorectal carcinoma. Patients and Methods: 46 patients received extended resection and single plastic tubes were sutured directly onto the tumor bed. IMBT was started within 2 weeks postoperatively with a median dose of 24.5 Gy (5-35 Gy). Patients were treated either with high-dose-rate brachytherapy (HDR; n=23) or with pulsed-dose-rate brachytherapy (PDR; n=23). 25 patients received complementary 45-Gy external-beam irradiation (EBRT) to the pelvic region after explanting the plastic tubes. Results: Median follow-up was 20.6 months (7-107 months) and mean patient survival 25.7±25.8 months (median 17, range 1-107 months). After 5 years overall survival, disease-free survival and local control rate were 23%, 20% and 33%, significantly influenced by the resectional state. There was a trend in favor of PDR compared to HDR, which reached statistical significance in patients who had not received additional EBRT. Conclusion: The combination of extended surgery and postoperative interstitial IMBT is feasible and offers effective interdisciplinary treatment of recurrent colorectal cancer. In this small and inhomogeneous cohort of patients PDR seems to be more effective than HDR, particularly when application of complementary EBRT is not possible. None of the patients who required resection of distant metastasis survived >2 years in this study. (orig.)

  4. Development of a TLD mailed system for remote dosimetry audit for 192Ir HDR and PDR sources

    International Nuclear Information System (INIS)

    Roue, Amelie; Venselaar, Jack L.M.; Ferreira, Ivaldo H.; Bridier, Andre; Dam, Jan van

    2007-01-01

    Background and purpose: In the framework of an ESTRO ESQUIRE project, the BRAPHYQS Physics Network and the EQUAL-ESTRO laboratory have developed a procedure for checking the absorbed dose to water in the vicinity of HDR or PDR sources using a mailed TLD system. The methodology and the materials used in the procedure are based on the existing EQUAL-ESTRO external radiotherapy dose checks. Materials and methods: A phantom for TLD postal dose assurance service, adapted to accept catheters from different HDR afterloaders, has been developed. The phantom consists of three PMMA tubes supporting catheters placed at 120 degrees around a central TLD holder. A study on the use of LiF powder type DTL 937 (Philitech) has been performed in order to establish the TLD calibration in dose-to-water at a given distance from 192 Ir source, as well as to determine all correction factors to convert the TLD reading into absorbed dose to water. The dosimetric audit is based on the comparison between the dose to water measured with the TL dosimeter and the dose calculated by the clinical TPS. Results of the audits are classified in four different levels depending on the ratio of the measured dose to the stated dose. The total uncertainty budget in the measurement of the absorbed dose to water using TLD near an 192 Ir HDR source, including TLD reading, correction factors and TLD calibration coefficient, is determined as 3.27% (1 s). Results: To validate the procedures, the external audit was first tested among the members of the BRAPHYQS Network. Since November 2004, the test has been made available for use by all European brachytherapy centres. To date, 11 centres have participated in the checks and the results obtained are very encouraging. Nevertheless, one error detected has shown the usefulness of this audit. Conclusion: A method of absorbed dose to water determination in the vicinity of an 192 Ir brachytherapy source was developed for the purpose of a mailed TL dosimetry system. The

  5. Development of a TLD mailed system for remote dosimetry audit for (192)Ir HDR and PDR sources.

    Science.gov (United States)

    Roué, Amélie; Venselaar, Jack L M; Ferreira, Ivaldo H; Bridier, André; Van Dam, Jan

    2007-04-01

    In the framework of an ESTRO ESQUIRE project, the BRAPHYQS Physics Network and the EQUAL-ESTRO laboratory have developed a procedure for checking the absorbed dose to water in the vicinity of HDR or PDR sources using a mailed TLD system. The methodology and the materials used in the procedure are based on the existing EQUAL-ESTRO external radiotherapy dose checks. A phantom for TLD postal dose assurance service, adapted to accept catheters from different HDR afterloaders, has been developed. The phantom consists of three PMMA tubes supporting catheters placed at 120 degrees around a central TLD holder. A study on the use of LiF powder type DTL 937 (Philitech) has been performed in order to establish the TLD calibration in dose-to-water at a given distance from (192)Ir source, as well as to determine all correction factors to convert the TLD reading into absorbed dose to water. The dosimetric audit is based on the comparison between the dose to water measured with the TL dosimeter and the dose calculated by the clinical TPS. Results of the audits are classified in four different levels depending on the ratio of the measured dose to the stated dose. The total uncertainty budget in the measurement of the absorbed dose to water using TLD near an (192)Ir HDR source, including TLD reading, correction factors and TLD calibration coefficient, is determined as 3.27% (1s). To validate the procedures, the external audit was first tested among the members of the BRAPHYQS Network. Since November 2004, the test has been made available for use by all European brachytherapy centres. To date, 11 centres have participated in the checks and the results obtained are very encouraging. Nevertheless, one error detected has shown the usefulness of this audit. A method of absorbed dose to water determination in the vicinity of an (192)Ir brachytherapy source was developed for the purpose of a mailed TL dosimetry system. The accuracy of the procedure was determined. This method allows a

  6. MEMO radiology

    International Nuclear Information System (INIS)

    Wagner-Manslau, C.

    1989-01-01

    This radiology volume is a concise handbook of imaging techniques, nuclear medicine, and radiation therapy, albeit that the main emphasis is on classic radiology. It offers, for instance, a survey of radiological findings for the most frequent pathological conditions, many overviews of differential diagnosis, a glossary of the technical bases of radiology and so forth. The contents are divided into the following chapters: Physical and biological bases; skeleton; thorax with the subdivisions lungs, heart, mediastinum, and pleura; gastrointestinal tract with the subsections esophagus, small and large intestine; liver; biliary tract; pancreas; retroperitoneal space; kidney; suprarenal glands; bladder; blood vessels, lymph nodes, spleen; mammary glands; female genitals; prostate and scrotum, epididymis and seminal vesicle. (orig./MG) With 23 figs [de

  7. Radiology and fine art.

    Science.gov (United States)

    Marinković, Slobodan; Stošić-Opinćal, Tatjana; Tomić, Oliver

    2012-07-01

    The radiologic aesthetics of some body parts and internal organs have inspired certain artists to create specific works of art. Our aim was to describe the link between radiology and fine art. We explored 13,625 artworks in the literature produced by 2049 artists and found several thousand photographs in an online image search. The examination revealed 271 radiologic artworks (1.99%) created by 59 artists (2.88%) who mainly applied radiography, sonography, CT, and MRI. Some authors produced radiologic artistic photographs, and others used radiologic images to create artful compositions, specific sculptures, or digital works. Many radiologic artworks have symbolic, metaphoric, or conceptual connotations. Radiology is clearly becoming an original and important field of modern art.

  8. Radiological protection of patients in diagnostic and interventional radiology, nuclear medicine and radiotherapy. Contributed papers

    International Nuclear Information System (INIS)

    2001-01-01

    An International Conference on the Radiological Protection of Patients in Diagnostic and Interventional Radiology, Nuclear Medicine and Radiotherapy organized by the International Atomic Energy Agency and co-sponsored by the European Commission, the Pan American Health Organization and the World Health Organization was held in Malaga, Spain, from 26 to 30 March 2001. The Government of Spain hosted this Conference through the Ministerio de Sanidad y Consumo, the Consejo de Seguridad Nuclear, the Junta de Andalucia, the Universidad de Malaga and the Grupo de Investigacion en Proteccion Radiologica de la Universidad de Malaga (PRUMA). The Conference was organized in co-operation with the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Commission on Radiological Protection (ICRP) and the following professional societies: International Organization of Medical Physicists (IOMP), International Radiation Protection Association (IRPA), International Society of Radiation Oncology (ISRO), International Society of Radiology (ISR), International Society of Radiographers and Radiological Technologists (ISRRT) and World Federation of Nuclear Medicine and Biology (WFNMB). This publication contains contributed papers submitted to the Conference Programme Committee. The papers are in one of the two working languages of this Conference, English and Spanish. The topics covered by the Conference are as follows: Radiological protection of patients in general diagnostic radiology (radiography), Radiological protection of patients in general diagnostic radiology (fluoroscopy), Radiological protection issues in specific uses of diagnostic radiology, such as mammography and computed tomography (with special consideration of the impact of digital techniques), Radiological protection in interventional radiology, including fluoroscopy not carried out by radiologists, Radiological protection of patients in nuclear medicine, Developing and

  9. Radiological protection of patients in diagnostic and interventional radiology, nuclear medicine and radiotherapy. Contributed papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    An International Conference on the Radiological Protection of Patients in Diagnostic and Interventional Radiology, Nuclear Medicine and Radiotherapy organized by the International Atomic Energy Agency and co-sponsored by the European Commission, the Pan American Health Organization and the World Health Organization was held in Malaga, Spain, from 26 to 30 March 2001. The Government of Spain hosted this Conference through the Ministerio de Sanidad y Consumo, the Consejo de Seguridad Nuclear, the Junta de Andalucia, the Universidad de Malaga and the Grupo de Investigacion en Proteccion Radiologica de la Universidad de Malaga (PRUMA). The Conference was organized in co-operation with the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Commission on Radiological Protection (ICRP) and the following professional societies: International Organization of Medical Physicists (IOMP), International Radiation Protection Association (IRPA), International Society of Radiation Oncology (ISRO), International Society of Radiology (ISR), International Society of Radiographers and Radiological Technologists (ISRRT) and World Federation of Nuclear Medicine and Biology (WFNMB). This publication contains contributed papers submitted to the Conference Programme Committee. The papers are in one of the two working languages of this Conference, English and Spanish. The topics covered by the Conference are as follows: Radiological protection of patients in general diagnostic radiology (radiography), Radiological protection of patients in general diagnostic radiology (fluoroscopy), Radiological protection issues in specific uses of diagnostic radiology, such as mammography and computed tomography (with special consideration of the impact of digital techniques), Radiological protection in interventional radiology, including fluoroscopy not carried out by radiologists, Radiological protection of patients in nuclear medicine, Developing and

  10. Radiology and the mobile device: Radiology in motion

    Directory of Open Access Journals (Sweden)

    Sridhar G Panughpath

    2012-01-01

    Full Text Available The use of mobile devices is revolutionizing the way we communicate, interact, are entertained, and organize our lives. With healthcare in general and radiology in particular becoming increasingly digital, the use of such devices in radiologic practice is inevitable. This article reviews the current status of the use of mobile devices in the clinical practice of radiology, namely in emergency teleradiology. Technical parameters such as luminance and resolution are discussed. The article also discusses the benefits of such mobility vis-à-vis the current limitations of the technologies available.

  11. Radiology and the mobile device: Radiology in motion

    International Nuclear Information System (INIS)

    Panughpath, Sridhar G; Kalyanpur, Arjun

    2012-01-01

    The use of mobile devices is revolutionizing the way we communicate, interact, are entertained, and organize our lives. With healthcare in general and radiology in particular becoming increasingly digital, the use of such devices in radiologic practice is inevitable. This article reviews the current status of the use of mobile devices in the clinical practice of radiology, namely in emergency teleradiology. Technical parameters such as luminance and resolution are discussed. The article also discusses the benefits of such mobility vis-à-vis the current limitations of the technologies available

  12. Bacteriological Monitoring of Radiology Room Apparatus in the Department of Radiological Technology and Contamination on Hands of Radiological Technologists

    International Nuclear Information System (INIS)

    Kim, Seon Chil

    2008-01-01

    Distribution of microorganisms were examined for the bucky tables in the radiology rooms of the department of radiological technology, the aprons, handles of various apparatus, handles of mobile radiological apparatus, and hands of the radiological technologists. As a result, relatively larger amounts of bacteria were found on the handles of the mobile radiological apparatus and the aprons. Among the isolated bacteria, Acinetobacter baumanni (7.3%), Klebsiella pneumoniae (6.7%), Staphylococcus aureus (3.9%), Serratia liquefaciens (1.7%), Enterobacter cloaceae (0.6%), Providenica rettgeri (0.6%) are known as the cause of nosocomial infection (hospital acquired infection). In addition, similar colonies were also found on the hands of the radiological technologists such as microorganisms of Klebsiella pneumoniae (8.4%), Staphylococcus aureus (6.6%), Yersinia enterocolotica (5.4%), Acinetobacter baumanni (4.2%), Enterobacter cloaceae (2.4%), Serratia liquefaciens (1.8%), Yersinia pseuotuberculosis (18%), Enterobacter sakazakii (1.2%), and Escherichia coli (0.6%). In particular, this result indicates clinical significance since Staphylococcus aureus and Escherichia coli show strong pathogenicity. Therefore, a continuous education is essential for the radiological technologists to prevent the nosocomial infection.

  13. Bacteriological Monitoring of Radiology Room Apparatus in the Department of Radiological Technology and Contamination on Hands of Radiological Technologists

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Chil [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of)

    2008-12-15

    Distribution of microorganisms were examined for the bucky tables in the radiology rooms of the department of radiological technology, the aprons, handles of various apparatus, handles of mobile radiological apparatus, and hands of the radiological technologists. As a result, relatively larger amounts of bacteria were found on the handles of the mobile radiological apparatus and the aprons. Among the isolated bacteria, Acinetobacter baumanni (7.3%), Klebsiella pneumoniae (6.7%), Staphylococcus aureus (3.9%), Serratia liquefaciens (1.7%), Enterobacter cloaceae (0.6%), Providenica rettgeri (0.6%) are known as the cause of nosocomial infection (hospital acquired infection). In addition, similar colonies were also found on the hands of the radiological technologists such as microorganisms of Klebsiella pneumoniae (8.4%), Staphylococcus aureus (6.6%), Yersinia enterocolotica (5.4%), Acinetobacter baumanni (4.2%), Enterobacter cloaceae (2.4%), Serratia liquefaciens (1.8%), Yersinia pseuotuberculosis (18%), Enterobacter sakazakii (1.2%), and Escherichia coli (0.6%). In particular, this result indicates clinical significance since Staphylococcus aureus and Escherichia coli show strong pathogenicity. Therefore, a continuous education is essential for the radiological technologists to prevent the nosocomial infection.

  14. Braquiterapia endoluminal HDR no tratamento de tumores primários ou recidivas na árvore traqueobrônquica

    Directory of Open Access Journals (Sweden)

    Maria Fortunato

    2009-03-01

    Full Text Available Resumo: Introdução: Tumores localmente avançados como forma de apresentação inicial dos tumores localizados na árvore traqueobrônquica não são um fenómeno raro. A recidiva brônquica é um acontecimento frequente na história natural de algumas neoplasias. As opções terapêuticas são múltiplas, sendo no entanto dependentes de variáveis, como a terapêutica inicial utilizada, o local da recorrência, a sintomatologia e as condições físicas do doente.Objectivos: Demonstrar as principais vantagens terapêuticas da braquiterapia endoluminal (BTE com alta taxa de dose (HDR em tumores primários e na recidiva tumoral localizada na árvore traqueobrônquica.Material e métodos: Avaliámos retrospectivamente sete doentes (dts com tumor primário do cólon, traqueia e pulmão. A recidiva traqueobrônquica (dois dts na traqueia e cinco dts no brônquio ocorreu entre Março de 2003 e Setembro de 2004, os dts foram submetidos a BT HDR como terapêutica primária ou na recidiva, em associação com RTE, laserterapia e quimioterapia (QT, com intuito paliativo/curativo. Na BTE HDR foram utilizadas doses de 5 a 7 Gy em duas a quatro fracções, prescritas a 1 cm do eixo da fonte. O tratamento consistiu na aplicação endoluminal de Ir192, utilizando um cateter 6 French.Resultados: Verificámos o rápido alívio sintomático associado à redução da massa tumoral em seis dos sete doentes submetidos a esta técnica. Em um dos seis doentes estudados observouse uma progressão da doença local entre a 2.ª e a 3.ª fracções de tratamento (obstrução da traqueia. Com um follow-up mediano entre a terapêutica com BT e a avaliação do presente estudo de 17 meses (2-40, três doentes estão vivos, um sem evidência de doença e dois apresentam uma recidiva brônquica; quatro faleceram, um após hemoptise

  15. Increasing Fractional Doses Increases the Probability of Benign PSA Bounce in Patients Undergoing Definitive HDR Brachytherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, Carlin R.; Ye, Hong; Chen, Peter Y.; Gustafson, Gary S.; Limbacher, Amy; Krauss, Daniel J., E-mail: Daniel.krauss@beaumont.edu

    2017-05-01

    Purpose: Prostate-specific antigen (PSA) bounce is a temporary elevation of the PSA level above a prior nadir. The purpose of this study was to determine whether the frequency of a PSA bounce following high-dose-rate (HDR) interstitial brachytherapy for the treatment of prostate cancer is associated with individual treatment fraction size. Methods and Materials: Between 1999 and 2014, 554 patients underwent treatment of low- or intermediate-risk prostate cancer with definitive HDR brachytherapy as monotherapy and had ≥3 subsequent PSA measurements. Four different fraction sizes were used: 950 cGy × 4 fractions, 1200 cGy × 2 fractions, 1350 cGy × 2 fractions, 1900 cGy × 1 fraction. Four definitions of PSA bounce were applied: ≥0.2, ≥0.5, ≥1.0, and ≥2.0 ng/mL above the prior nadir with a subsequent return to the nadir. Results: The median follow-up period was 3.7 years. The actuarial 3-year rate of PSA bounce for the entire cohort was 41.3%, 28.4%, 17.4%, and 6.8% for nadir +0.2, +0.5, +1.0, and +2.0 ng/mL, respectively. The 3-year rate of PSA bounce >0.2 ng/mL was 42.2%, 32.1%, 41.0%, and 59.1% for the 950-, 1200-, 1350-, and 1900-cGy/fraction levels, respectively (P=.002). The hazard ratio for bounce >0.2 ng/mL for patients receiving a single fraction of 1900 cGy compared with those receiving treatment in multiple fractions was 1.786 (P=.024). For patients treated with a single 1900-cGy fraction, the 1-, 2-, and 3-year rates of PSA bounce exceeding the Phoenix biochemical failure definition (nadir +2 ng/mL) were 4.5%, 18.7%, and 18.7%, respectively, higher than the rates for all other administered dose levels (P=.025). Conclusions: The incidence of PSA bounce increases with single-fraction HDR treatment. Knowledge of posttreatment PSA kinetics may aid in decision making regarding management of potential biochemical failures.

  16. Increasing Fractional Doses Increases the Probability of Benign PSA Bounce in Patients Undergoing Definitive HDR Brachytherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Hauck, Carlin R.; Ye, Hong; Chen, Peter Y.; Gustafson, Gary S.; Limbacher, Amy; Krauss, Daniel J.

    2017-01-01

    Purpose: Prostate-specific antigen (PSA) bounce is a temporary elevation of the PSA level above a prior nadir. The purpose of this study was to determine whether the frequency of a PSA bounce following high-dose-rate (HDR) interstitial brachytherapy for the treatment of prostate cancer is associated with individual treatment fraction size. Methods and Materials: Between 1999 and 2014, 554 patients underwent treatment of low- or intermediate-risk prostate cancer with definitive HDR brachytherapy as monotherapy and had ≥3 subsequent PSA measurements. Four different fraction sizes were used: 950 cGy × 4 fractions, 1200 cGy × 2 fractions, 1350 cGy × 2 fractions, 1900 cGy × 1 fraction. Four definitions of PSA bounce were applied: ≥0.2, ≥0.5, ≥1.0, and ≥2.0 ng/mL above the prior nadir with a subsequent return to the nadir. Results: The median follow-up period was 3.7 years. The actuarial 3-year rate of PSA bounce for the entire cohort was 41.3%, 28.4%, 17.4%, and 6.8% for nadir +0.2, +0.5, +1.0, and +2.0 ng/mL, respectively. The 3-year rate of PSA bounce >0.2 ng/mL was 42.2%, 32.1%, 41.0%, and 59.1% for the 950-, 1200-, 1350-, and 1900-cGy/fraction levels, respectively (P=.002). The hazard ratio for bounce >0.2 ng/mL for patients receiving a single fraction of 1900 cGy compared with those receiving treatment in multiple fractions was 1.786 (P=.024). For patients treated with a single 1900-cGy fraction, the 1-, 2-, and 3-year rates of PSA bounce exceeding the Phoenix biochemical failure definition (nadir +2 ng/mL) were 4.5%, 18.7%, and 18.7%, respectively, higher than the rates for all other administered dose levels (P=.025). Conclusions: The incidence of PSA bounce increases with single-fraction HDR treatment. Knowledge of posttreatment PSA kinetics may aid in decision making regarding management of potential biochemical failures.

  17. Portrayal of radiology in a major medical television series: How does it influence the perception of radiology among patients and radiology professionals?

    International Nuclear Information System (INIS)

    Heye, T.; Merkle, E.M.; Boll, D.T.; Leyendecker, J.R.; Gupta, R.T.

    2016-01-01

    To assess how the portrayal of Radiology on medical TV shows is perceived by patients and radiology professionals. In this IRB-approved study with patient consent waived, surveys were conducted among adult patients scheduled for radiological examinations and radiology professionals. The questionnaire investigated medical TV watching habits including interest in medical TV shows, appearance of radiological examination/staff, radiology's role in diagnosis-making, and rating of the shows' accuracy in portraying radiology relative to reality. One hundred and twenty-six patients and 240 professionals (133 technologists, 107 radiologists) participated. 63.5 % patients and 63.2 % technologists rated interest in medical TV shows ≥5 (scale 1-10) versus 38.3 % of radiologists. All groups noted regular (every 2nd/3rd show) to >1/show appearance of radiological examinations in 58.5-88.2 % compared to 21.0-46.2 % for radiological staff appearance. Radiology played a role in diagnosis-making regularly to >1/show in 45.3-52.6 %. There is a positive correlation for interest in medical TV and the perception that radiology is accurately portrayed for patients (r = 0.49; P = 0.001) and technologists (r = 0.38; P = 0.001) but not for radiologists (r = 0.01). The majority of patients perceive the portrayed content as accurate. Radiologists should be aware of this cultivation effect to understand their patients' behaviour which may create false expectations towards radiological examinations and potential safety hazards. (orig.)

  18. Current radiology. Volume 5

    International Nuclear Information System (INIS)

    Wilson, G.H.; Hanafee, W.N.

    1984-01-01

    This book contains 10 selections. They are: Nuclear Magnetic Resonance Imaging, Interventional Vascular Radiology, Genitourinary Radiology, Skeletal Radiology, Digital Subtraction Angiography, Neuroradiology, Computed Tomographic Evaluation of Degenerative Diseases of the Lumbar Spine, The Lung, Otolaringology and Opthalmology, and Pediatric Radiology: Cranial, Facial, Cervical, Vertebral, and Appendicular

  19. WE-A-17A-10: Fast, Automatic and Accurate Catheter Reconstruction in HDR Brachytherapy Using An Electromagnetic 3D Tracking System

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, E; Racine, E; Beaulieu, L [CHU de Quebec - Universite Laval, Quebec, Quebec (Canada); Binnekamp, D [Integrated Clinical Solutions and Marketing, Philips Healthcare, Best, DA (Netherlands)

    2014-06-15

    Purpose: In high dose rate brachytherapy (HDR-B), actual catheter reconstruction protocols are slow and errors prompt. The purpose of this study was to evaluate the accuracy and robustness of an electromagnetic (EM) tracking system for improved catheter reconstruction in HDR-B protocols. Methods: For this proof-of-principle, a total of 10 catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a Philips-design 18G biopsy needle (used as an EM stylet) and the second generation Aurora Planar Field Generator from Northern Digital Inc. The Aurora EM system exploits alternating current technology and generates 3D points at 40 Hz. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical CT system with a resolution of 0.089 mm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, 5 catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 seconds or less. This would imply that for a typical clinical implant of 17 catheters, the total reconstruction time would be less than 3 minutes. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.92 ± 0.37 mm and 1.74 ± 1.39 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be significantly more accurate (unpaired t-test, p < 0.05). A mean difference of less than 0.5 mm was found between successive EM reconstructions. Conclusion: The EM reconstruction was found to be faster, more accurate and more robust than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators. We would like to disclose that the equipments, used in this study, is coming from a collaboration with Philips Medical.

  20. WE-A-17A-10: Fast, Automatic and Accurate Catheter Reconstruction in HDR Brachytherapy Using An Electromagnetic 3D Tracking System

    International Nuclear Information System (INIS)

    Poulin, E; Racine, E; Beaulieu, L; Binnekamp, D

    2014-01-01

    Purpose: In high dose rate brachytherapy (HDR-B), actual catheter reconstruction protocols are slow and errors prompt. The purpose of this study was to evaluate the accuracy and robustness of an electromagnetic (EM) tracking system for improved catheter reconstruction in HDR-B protocols. Methods: For this proof-of-principle, a total of 10 catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a Philips-design 18G biopsy needle (used as an EM stylet) and the second generation Aurora Planar Field Generator from Northern Digital Inc. The Aurora EM system exploits alternating current technology and generates 3D points at 40 Hz. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical CT system with a resolution of 0.089 mm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, 5 catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 seconds or less. This would imply that for a typical clinical implant of 17 catheters, the total reconstruction time would be less than 3 minutes. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.92 ± 0.37 mm and 1.74 ± 1.39 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be significantly more accurate (unpaired t-test, p < 0.05). A mean difference of less than 0.5 mm was found between successive EM reconstructions. Conclusion: The EM reconstruction was found to be faster, more accurate and more robust than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators. We would like to disclose that the equipments, used in this study, is coming from a collaboration with Philips Medical

  1. Medical Ethics in Radiology

    International Nuclear Information System (INIS)

    Kim, Kyung Won; Park, Jae Hyung; Yoon, Soon Ho

    2010-01-01

    According to the recent developments in radiological techniques, the role of radiology in the clinical management of patients is ever increasing and in turn, so is the importance of radiology in patient management. Thus far, there have been few open discussions about medical ethics related to radiology in Korea. Hence, concern about medical ethics as an essential field of radiology should be part of an improved resident training program and patient management. The categories of medical ethics related with radiology are ethics in the radiological management of patient, the relationship of radiologists with other medical professionals or companies, the hazard level of radiation for patients and radiologists, quality assurance of image products and modalities, research ethics, and other ethics issues related to teleradiology and fusion imaging. In order to achieve the goal of respectful progress in radiology as well as minimizing any adverse reaction from other medical professions or society, we should establish a strong basis of medical ethics through the continuous concern and self education

  2. Analysis of papers in radiological journals in recent years: a comparison of journal of Korean radiologic society and radiology

    International Nuclear Information System (INIS)

    Kim, Jin Suh; Kim, Jae Kyun; Han, Dong Bok; Lim, Tae Hwan

    1997-01-01

    The purpose of this study was to determine current trends and the mode of future development in the field of medical radiology and to promote research among the nation's radiologists by analyzing the contents of the Journal of the Korean Radiologic Society(JKRS) and Radiology. The number of articles published in JKRS each year between 1990 and 1994 was counted. The research articles in JKRS(n=740) and in Radiology(n=1748) between 1992 and 1994 were categorized according to the objective, type, topic, materials, and radiologic techniques of their contents on the basis of predetermined criteria. Domestic Masters theses(n=126) and doctoral dissertations(n=75) accepted between 1990 and 1994, and domestic materials published in international journals (n=416) between 1986 and 1994 were also categorized using the same criteria. The greatest increase in the number of articles published in JKRS was seen during 1994. The majority of these aimed to retrospectively analyse the findings of diseases while the majority of articles published in Radiology dealt prospectively with the development and/or evaluation of diagnostic methods. More variety of topics and issues was seen in Radiology than in JKRS. The number of articles of domestic materials published in international journals increased from 1986 to 1994, while the number of articles of foreign materials published in Korea was relatively stationary : A significant number of theses and dissertations dealt, mostly prospectively, with studies of pathophysiologic and/or pharmacologic mechanisms using animal models. In order to understand both current trends and the direction and mode of future developments in the field of radiology, and to be able to actively deal with challenges at the forefront of radiologic development, it is essential to review research articles published in radiology-related journals

  3. Value of palliation and improvement in quality of life in oesophageal cancer patients treated with iridium - 192 HDR fractionated brachytherapy

    International Nuclear Information System (INIS)

    Biaias, B.; Kaleta, R.; Fijaikowski, M.

    1996-01-01

    During December 1992 - November 1995 twenty-two patients with oesophageal cancer were treated with palliative HDR brachytherapy. Sixteen patients had local recurrence or progression after external radiotherapy and the remaining six patients were treated with brachytherapy alone. All patients received fractions of 7.5 Gy at the reference point 2 - 4 time weekly. Reference point was calculated at 0.5 cm distance from applicator surface. Microselectron HDR device with Iridium-192 source were used. Criteria for palliative effect were as follow: relive of symptoms time of occurrence and duration of palliative effect. Quality of life during and after treatment were evaluated by patients and staff independently. In majority of patients both palliative effect and significant improvement of quality of life were noted. Detail results include: - improvement in swallowing in 63,6% ((14(22))); - increase in body weight in 45% ((10(22))); - pain relive 70% ((12(17))); - appearance of palliation 1 hour - 8 days; - duration of palliation - 3-12 mo. (median 5 mo.); Quality of live - improvement - 59% ((13(22))); - no improvement - 27.3% ((6(22))); - worsening - 13.7% ((3(22))); No improvement or worsening in quality of life were observed only in patients who obtained radical radiotherapy previously. Brachytherapy is an effective method of palliative treatment for as well primary and recurrent oesophageal cancer

  4. Air kerma standard for calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources and its traceability

    Energy Technology Data Exchange (ETDEWEB)

    Di Prinzio, Renato; Almeida, Carlos Eduardo de [Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil) and Instituto de Radioprotecao e Dosimetria-Comissao Nacional de Energia Nuclear (IRD/CNEN), Av. Salvador Allende, s/n, Jacarepagua-CE22780-160-Rio de Janeiro, RJ (Brazil); Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil)

    2009-03-15

    In Brazil there are over 100 high dose rate (HDR) brachytherapy facilities using well-type chambers for the determination of the air kerma rate of {sup 192}Ir sources. This paper presents the methodology developed and extensively tested by the Laboratorio de Ciencias Radiologicas (LCR) and presently in use to calibrate those types of chambers. The system was initially used to calibrate six well-type chambers of brachytherapy services, and the maximum deviation of only 1.0% was observed between the calibration coefficients obtained and the ones in the calibration certificate provided by the UWADCL. In addition to its traceability to the Brazilian National Standards, the whole system was taken to University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) for a direct comparison and the same formalism to calculate the air kerma was used. The comparison results between the two laboratories show an agreement of 0.9% for the calibration coefficients. Three Brazilian well-type chambers were calibrated at the UWADCL, and by LCR, in Brazil, using the developed system and a clinical HDR machine. The results of the calibration of three well chambers have shown an agreement better than 1.0%. Uncertainty analyses involving the measurements made both at the UWADCL and LCR laboratories are discussed.

  5. Machine Learning and Radiology

    Science.gov (United States)

    Wang, Shijun; Summers, Ronald M.

    2012-01-01

    In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. PMID:22465077

  6. Die Ukraine-Krise und kritische Fragen an die EU-Erweiterungspolitik

    OpenAIRE

    Lippert, Barbara

    2014-01-01

    Die Ukraine-Krise konfrontiert die EU mit kritischen Fragen zu ihrer Erweiterungs-politik. Muss sie nach der Osterweiterung 2004/07 und dem gerade erst begonnenen Einzug der Westbalkan-Staaten nun mit Osteuropa für die übernächste Erweiterungs-runde rechnen? Sollte sie sich gar alsbald politisch verpflichten, interessierte und beitrittsfähige osteuropäische Länder eines Tages aufzunehmen? Wie jetzt auch viel-fach von EU-Akteuren geäußert, wäre dies voreilig: Denn in der konfliktgeladenen und ...

  7. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    International Nuclear Information System (INIS)

    Balvert, Marleen; Gorissen, Bram L; Den Hertog, Dick; Hoffmann, Aswin L

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D 90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2–5 cc. However, this comes at a cost of a reduction in D 90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D 90% against uncertainty in dwell positions for both models. (paper)

  8. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    Science.gov (United States)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  9. Pediatric radiology malpractice claims - characteristics and comparison to adult radiology claims

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Micheal A.; Taylor, George A. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Dwyer, Kathy; Yu-Moe, Winnie [CRICO Risk Management Foundation, Boston, MA (United States)

    2017-06-15

    Medical malpractice is the primary method by which people who believe they have suffered an injury in the course of medical care seek compensation in the United States and Canada. An increasing body of research demonstrates that failure to correctly diagnose is the most common allegation made in malpractice claims against radiologists. Since the 1994 survey by the Society of Chairmen of Radiology in Children's Hospitals (SCORCH), no other published studies have specifically examined the frequency or clinical context of malpractice claims against pediatric radiologists or arising from pediatric imaging interpretation. We hypothesize that the frequency, character and outcome of malpractice claims made against pediatric radiologists differ from those seen in general radiology practice. We searched the Controlled Risk Insurance Co. (CRICO) Strategies' Comparative Benchmarking System (CBS), a private repository of approximately 350,000 open and closed medical malpractice claims in the United States, for claims related to pediatric radiology. We further queried these cases for the major allegation, the clinical environment in which the claim arose, the clinical severity of the alleged injury, indemnity paid (if payment was made), primary imaging modality involved (if applicable) and primary International Classification of Diseases, 9th revision (ICD-9) diagnosis underlying the claim. There were a total of 27,056 fully coded claims of medical malpractice in the CBS database in the 5-year period between Jan. 1, 2010, and Dec. 31, 2014. Of these, 1,472 cases (5.4%) involved patients younger than 18 years. Radiology was the primary service responsible for 71/1,472 (4.8%) pediatric cases. There were statistically significant differences in average payout for pediatric radiology claims ($314,671) compared to adult radiology claims ($174,033). The allegations were primarily diagnosis-related in 70% of pediatric radiology claims. The most common imaging modality

  10. Pediatric radiology malpractice claims - characteristics and comparison to adult radiology claims

    International Nuclear Information System (INIS)

    Breen, Micheal A.; Taylor, George A.; Dwyer, Kathy; Yu-Moe, Winnie

    2017-01-01

    Medical malpractice is the primary method by which people who believe they have suffered an injury in the course of medical care seek compensation in the United States and Canada. An increasing body of research demonstrates that failure to correctly diagnose is the most common allegation made in malpractice claims against radiologists. Since the 1994 survey by the Society of Chairmen of Radiology in Children's Hospitals (SCORCH), no other published studies have specifically examined the frequency or clinical context of malpractice claims against pediatric radiologists or arising from pediatric imaging interpretation. We hypothesize that the frequency, character and outcome of malpractice claims made against pediatric radiologists differ from those seen in general radiology practice. We searched the Controlled Risk Insurance Co. (CRICO) Strategies' Comparative Benchmarking System (CBS), a private repository of approximately 350,000 open and closed medical malpractice claims in the United States, for claims related to pediatric radiology. We further queried these cases for the major allegation, the clinical environment in which the claim arose, the clinical severity of the alleged injury, indemnity paid (if payment was made), primary imaging modality involved (if applicable) and primary International Classification of Diseases, 9th revision (ICD-9) diagnosis underlying the claim. There were a total of 27,056 fully coded claims of medical malpractice in the CBS database in the 5-year period between Jan. 1, 2010, and Dec. 31, 2014. Of these, 1,472 cases (5.4%) involved patients younger than 18 years. Radiology was the primary service responsible for 71/1,472 (4.8%) pediatric cases. There were statistically significant differences in average payout for pediatric radiology claims ($314,671) compared to adult radiology claims ($174,033). The allegations were primarily diagnosis-related in 70% of pediatric radiology claims. The most common imaging modality implicated in

  11. Pediatric radiology malpractice claims - characteristics and comparison to adult radiology claims.

    Science.gov (United States)

    Breen, Micheál A; Dwyer, Kathy; Yu-Moe, Winnie; Taylor, George A

    2017-06-01

    Medical malpractice is the primary method by which people who believe they have suffered an injury in the course of medical care seek compensation in the United States and Canada. An increasing body of research demonstrates that failure to correctly diagnose is the most common allegation made in malpractice claims against radiologists. Since the 1994 survey by the Society of Chairmen of Radiology in Children's Hospitals (SCORCH), no other published studies have specifically examined the frequency or clinical context of malpractice claims against pediatric radiologists or arising from pediatric imaging interpretation. We hypothesize that the frequency, character and outcome of malpractice claims made against pediatric radiologists differ from those seen in general radiology practice. We searched the Controlled Risk Insurance Co. (CRICO) Strategies' Comparative Benchmarking System (CBS), a private repository of approximately 350,000 open and closed medical malpractice claims in the United States, for claims related to pediatric radiology. We further queried these cases for the major allegation, the clinical environment in which the claim arose, the clinical severity of the alleged injury, indemnity paid (if payment was made), primary imaging modality involved (if applicable) and primary International Classification of Diseases, 9th revision (ICD-9) diagnosis underlying the claim. There were a total of 27,056 fully coded claims of medical malpractice in the CBS database in the 5-year period between Jan. 1, 2010, and Dec. 31, 2014. Of these, 1,472 cases (5.4%) involved patients younger than 18 years. Radiology was the primary service responsible for 71/1,472 (4.8%) pediatric cases. There were statistically significant differences in average payout for pediatric radiology claims ($314,671) compared to adult radiology claims ($174,033). The allegations were primarily diagnosis-related in 70% of pediatric radiology claims. The most common imaging modality implicated in

  12. Radiological protection and quality control for diagnostic radiology in China

    International Nuclear Information System (INIS)

    Baorong, Yue

    2008-01-01

    Full text: There are 43,000 diagnostic departments, nearly 70,000 X-ray diagnostic facilities, 7,000 CT, 250 million for the annual total numbers of X-ray examinations, 120,000 occupationally exposed workers in diagnostic radiology. 'Basic standards for protection against ionizing radiation and for the safety of radiation sources' is promulgated on October, 2002. This basic standard follows the BSS. 'Rule on the administration of radio-diagnosis and radiotherapy', as a order of the Ministry of Health No. 46, is promulgated by Minister of Health on January 24, 2006. It includes general provisions, requirements and practice, establishment and approval of radio-diagnosis and radiotherapy services, safeguards and quality assurance, and so on. There are a series of radiological protection standards and quality control standards in diagnostic radiology, including 'radiological protection standard for the examination in X-ray diagnosis', 'radiological health protection standards for X-ray examination of child-bearing age women and pregnant women', 'radiological protection standards for the children in X-ray diagnosis', 'standards for radiological protection in medical X-ray diagnosis', 'specification for radiological protection monitoring in medical X-ray diagnosis', 'guide for reasonable application of medical X-ray diagnosis', 'general aspects for quality assurance in medical X-ray image of diagnosis', 'specification of image quality control test for the medical X-ray diagnostic equipment', 'specification of image quality assurance test for X-ray equipment for computed tomography', 'specification for testing of quality control in computed radiography (CR)' and 'specification for testing of quality control in X-ray mammography'. With the X-ray diagnostic equipment, there are acceptant tests, status tests and routing tests in large hospitals. It is poor for routing test in middle and smaller hospitals. CT is used widely in diagnostic radiology, however most workers in CT

  13. Machine learning and radiology.

    Science.gov (United States)

    Wang, Shijun; Summers, Ronald M

    2012-07-01

    In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. Copyright © 2012. Published by Elsevier B.V.

  14. Radiology in Medical Education: A Pediatric Radiology Elective as a Template for Other Radiology Courses.

    Science.gov (United States)

    Hilmes, Melissa A; Hyatt, Eddie; Penrod, Cody H; Fleming, Amy E; Singh, Sudha P

    2016-03-01

    Traditionally, the pediatric radiology elective for medical students and pediatric residents constituted a morning teaching session focused mainly on radiography and fluoroscopy. A more structured elective was desired to broaden the exposure to more imaging modalities, create a more uniform educational experience, and include assessment tools. In 2012, an introductory e-mail and formal syllabus, including required reading assignments, were sent to participants before the start date. A rotating weekly schedule was expanded to include cross-sectional imaging (ultrasound, CT, MR) and nuclear medicine. The schedule could accommodate specific goals of the pediatric resident or medical student, as requested. Starting in 2013, an online pre-test and post-test were developed, as well as an online end-of-rotation survey specific to the pediatric radiology elective. Taking the Image Gently pledge was required. A scavenger hunt tool, cue cards, and electronic modules were added. Pre-test and post-test scores, averaged over 2 years, showed improvement in radiology knowledge, with scores increasing by 27% for medical students and 21% for pediatric residents. Surveys at the end of the elective were overwhelmingly positive, with constructive criticism and complimentary comments. We have successfully created an elective experience in radiology that dedicates time to education while preserving the workflow of radiologists. We have developed tools to provide a customized experience with many self-directed learning opportunities. Our tools and techniques are easily translatable to a general or adult radiology elective. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  15. Fat Necrosis After Partial-Breast Irradiation With Brachytherapy or Electron Irradiation Versus Standard Whole-Breast Radiotherapy-4-Year Results of a Randomized Trial

    International Nuclear Information System (INIS)

    Loevey, Katalin; Fodor, Janos; Major, Tibor; Szabo, Eva; Orosz, Zsolt; Sulyok, Zoltan; Janvary, Levente; Froehlich, Georgina; Kasler, Miklos; Polgar, Csaba

    2007-01-01

    Purpose: To examine the incidence and clinical relevance of fat necrosis after accelerated partial-breast irradiation (PBI) using interstitial high-dose-rate brachytherapy (HDR-BT) in comparison with partial-breast electron irradiation (ELE) and whole-breast irradiation (WBI). Methods and Materials: Between 1998 and 2004, 258 early-stage breast cancer patients were randomized to receive 50 Gy WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy HDR-BT (n = 88) or 50 Gy ELE (n = 40). The incidence of fat necrosis, its impact on cosmetic outcome, accompanying radiologic features, and clinical symptoms were evaluated. Results: The 4-year actuarial rate of fat necrosis was 31.1% for all patients, and 31.9%, 36.5%, and 17.7% after WBI, HDR-BT and ELE, respectively (p WBI/HDR-BT = 0.26; p WBI/ELE = 0.11; p ELE/HDR-BT = 0.025). The respective rate of asymptomatic fat necrosis was 20.2%, 25.3%, and 10% of patients. The incidence of symptomatic fat necrosis was not significantly different after WBI (8.5%), HDR-BT (11.4%), and ELE (7.5%). Symptomatic fat necrosis was significantly associated with a worse cosmetic outcome, whereas asymptomatic fat necrosis was not. Fat necrosis was detectable with mammography and/or ultrasound in each case. Additional imaging examinations were required in 21% of cases and aspiration cytology in 42%. Conclusions: Asymptomatic fat necrosis is a common adverse event of breast-conserving therapy, having no significant clinical relevance in the majority of the cases. The incidence of both symptomatic and asymptomatic fat necrosis is similar after conventional WBI and accelerated partial-breast HDR-BT

  16. Experimental and theoretical investigations of soil-structure interaction effect at HDR-reactor-building

    International Nuclear Information System (INIS)

    Wassermann, K.

    1983-01-01

    Full-scale dynamic testing on intermediate and high levels was performed at the Heissdampfreaktor (HDR) in 1979. Various types of dynamic forces were applied and response of the reactor containment structure and internal components was measured. Precalculations of dynamic behaviour and response of the structure were made through different mathematical models for the structure and the underlying soil. Soil-Structure Interaction effects are investigated and different theoretical models are compared with experimental results. In each model, the soil is represented by springs attached to the structural model. Stiffnesses of springs are calculated by different finite-element idealizations and half-space approximations. Eigenfrequencies and damping values related to interaction effects (translation, rocking, torsion) are identified from test results. The comparisons of dynamic characteristic of the soil-structure system between precalculations and test results show good agreement in general. (orig.)

  17. Radiology education: a radiology curriculum for all medical students?

    Science.gov (United States)

    Zwaan, Laura; Kok, Ellen M; van der Gijp, Anouk

    2017-09-26

    Diagnostic errors in radiology are frequent and can cause severe patient harm. Despite large performance differences between radiologists and non-radiology physicians, the latter often interpret medical images because electronic health records make images available throughout the hospital. Some people argue that non-radiologists should not diagnose medical images at all, and that medical school should focus on teaching ordering skills instead of image interpretation skills. We agree that teaching ordering skills is crucial as most physicians will need to order medical images in their professional life. However, we argue that the availability of medical images is so ubiquitous that it is important that non-radiologists are also trained in the basics of medical image interpretation and, additionally in recognizing when radiological consultancy should be sought. In acute situations, basic image interpretations skills can be life-saving. We plead for a radiology curriculum for all medical students. This should include the interpretation of common abnormalities on chest and skeletal radiographs and a basic distinction of normal from abnormal images. Furthermore, substantial attention should be given to the correct ordering of radiological images. Finally, it is critical that students are trained in deciding when to consult a radiologist.

  18. Radiation protection and quality assurance in dental radiology: II. Panoramic radiology

    International Nuclear Information System (INIS)

    Jodar-Porlan, S.; Alcaraz, M.; Martinez-Beneyto, Y.; Saura-Iniesta, A.M.; Velasco-Hidalgo, E.

    2001-01-01

    This paper studies 278 official reports on quality assurance in dental radiology in the context of the first revision of these dental clinics, as a result of the entry into force of the regulations establishing the duties for these types of facilities. In the results section we present a quantitative analysis of the facilities equipped with an panoramic radiology apparatus, making a special reference to the brands they have available, as well as their physical features (kV, mA, filtration) and the deviations detected in their operation. Some of their features in the process of obtaining radiological images at those facilities (film control, development time, liquid renewal) are determined, and the average dose of ionising radiation used in order to obtain the same tooth radiological image is presented. This paper shows, in a quantitative way, the characteristic features of panoramic radiology in our medium. The study is intended to be continued during the next years, which would allow the assessment of the prospective improvement in dental radiological performances as a result of the newly established regulations. (author)

  19. Radiology education: a radiology curriculum for all medical students?

    NARCIS (Netherlands)

    Zwaan, Laura; Kok, E.M.; van der Gijp, Anouk

    2017-01-01

    Diagnostic errors in radiology are frequent and can cause severe patient harm. Despite large performance differences between radiologists and non-radiology physicians, the latter often interpret medical images because electronic health records make images available throughout the hospital. Some

  20. Radiological optimization

    International Nuclear Information System (INIS)

    Zeevaert, T.

    1998-01-01

    Radiological optimization is one of the basic principles in each radiation-protection system and it is a basic requirement in the safety standards for radiation protection in the European Communities. The objectives of the research, performed in this field at the Belgian Nuclear Research Centre SCK-CEN, are: (1) to implement the ALARA principles in activities with radiological consequences; (2) to develop methodologies for optimization techniques in decision-aiding; (3) to optimize radiological assessment models by validation and intercomparison; (4) to improve methods to assess in real time the radiological hazards in the environment in case of an accident; (5) to develop methods and programmes to assist decision-makers during a nuclear emergency; (6) to support the policy of radioactive waste management authorities in the field of radiation protection; (7) to investigate existing software programmes in the domain of multi criteria analysis. The main achievements for 1997 are given

  1. High-level seismic tests of piping at the HDR [Heissdampfreaktor

    International Nuclear Information System (INIS)

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Costello, J.F.

    1989-01-01

    As part of the second-phase testing at the Heissdampfreaktor (HDR) Test Facility in Kahl/Main, Federal Republic of Germany (FRG), high-level seismic experiments, designated SHAM, were performed on an in-plant piping system during the period of 19 April to 27 May 1988. The objectives of the SHAM experiments were to (1) study the response of piping subjected to seismic excitation levels that exceed design levels manifold and which may result in failure/plastification of pipe supports and pipe elements; (2) provide data for the validation of linear and nonlinear pipe response analyses; (3) compare and evaluate, under identical loading conditions, the performance of various dynamic support system, ranging from very flexible to very stiff support configurations; (4) establish seismic margins for piping, dynamic pipe supports, and pipe anchorages; and (5) investigate the response, operability, and fragility of dynamic supports and of a typical US gate valve under extreme levels of seismic excitation. A brief description of the SHAM tests is provided, followed by highlights of the test results that are given primarily in the form of maximum response values. Also presented are very limited comparisons of experimental data and pretest analytical predictions. 6 refs., 8 figs

  2. Radiology systems architecture.

    Science.gov (United States)

    Deibel, S R; Greenes, R A

    1996-05-01

    This article focuses on the software requirements for enterprise integration in radiology. The needs of a future radiology systems architecture are examined, both at a concrete functional level and at an abstract system-properties level. A component-based approach to software development is described and is validated in the context of each of the abstract system requirements for future radiology computing environments.

  3. Calculated organ doses using Monte Carlo simulations in a reference male phantom undergoing HDR brachytherapy applied to localized prostate carcinoma

    International Nuclear Information System (INIS)

    Candela-Juan, Cristian; Perez-Calatayud, Jose; Ballester, Facundo; Rivard, Mark J.

    2013-01-01

    Purpose: The aim of this study was to obtain equivalent doses in radiosensitive organs (aside from the bladder and rectum) when applying high-dose-rate (HDR) brachytherapy to a localized prostate carcinoma using 60 Co or 192 Ir sources. These data are compared with results in a water phantom and with expected values in an infinite water medium. A comparison with reported values from proton therapy and intensity-modulated radiation therapy (IMRT) is also provided. Methods: Monte Carlo simulations in Geant4 were performed using a voxelized phantom described in International Commission on Radiological Protection (ICRP) Publication 110, which reproduces masses and shapes from an adult reference man defined in ICRP Publication 89. Point sources of 60 Co or 192 Ir with photon energy spectra corresponding to those exiting their capsules were placed in the center of the prostate, and equivalent doses per clinical absorbed dose in this target organ were obtained in several radiosensitive organs. Values were corrected to account for clinical circumstances with the source located at various positions with differing dwell times throughout the prostate. This was repeated for a homogeneous water phantom. Results: For the nearest organs considered (bladder, rectum, testes, small intestine, and colon), equivalent doses given by 60 Co source were smaller (8%–19%) than from 192 Ir. However, as the distance increases, the more penetrating gamma rays produced by 60 Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a 60 Co source (11.1 mSv/Gy) is lower than from a 192 Ir source (13.2 mSv/Gy). On the other hand, equivalent doses were the same in the tissue and the homogeneous water phantom for those soft tissues closer to the prostate than about 30 cm. As the distance increased, the differences of photoelectric effect in water and soft tissue, and appearance of other materials such as air, bone, or lungs, produced

  4. Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer.

    Science.gov (United States)

    Ecke, Thorsten H; Huang-Tiel, Hui-Juan; Golka, Klaus; Selinski, Silvia; Geis, Berit Christine; Koswig, Stephan; Bathe, Katrin; Hallmann, Steffen; Gerullis, Holger

    2016-11-10

    High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D'Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis ( p = 0.009), PSA on date of first HDR-BT ( p = 0.033), and PSA on date of first follow-up after one year ( p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  5. Radiological controls integrated into design

    Energy Technology Data Exchange (ETDEWEB)

    Kindred, G.W. [Cleveland Electric Illuminating Co., Perry, OH (United States)

    1995-03-01

    Radiological controls are required by law in the design of commercial nuclear power reactor facilities. These controls can be relatively minor or significant, relative to cost. To ensure that radiological controls are designed into a project, the health physicist (radiological engineer) must be involved from the beginning. This is especially true regarding keeping costs down. For every radiological engineer at a nuclear power plant there must be fifty engineers of other disciplines. The radiological engineer cannot be an expert on every discipline of engineering. However, he must be knowledgeable to the degree of how a design will impact the facility from a radiological perspective. This paper will address how to effectively perform radiological analyses with the goal of radiological controls integrated into the design package.

  6. New era of the relationship between Chinese interventional radiology sub-society and journal of interventional radiology

    International Nuclear Information System (INIS)

    Li Linsun

    2009-01-01

    The past decades have witnessed interventional radiology in China to go from a very initial clinical practice to an important medical player in modern medicine. Recently, a friendly collaboration has been successfully established between the Chinese Interventional Radiology Sub-society and the Journal of Interventional Radiology. The Chinese Interventional Radiology Sub-society will take the full responsibility for the academic governance of the Journal of Interventional Radiology and the Journal of Interventional Radiology will formally become the sole interventional academic periodical of the Chinese Interventional Radiology Sub-society in China. This collaboration will surely make Chinese interventional radiology to initiate a new era,promote the further development of interventional radiology at home and enable the Journal of Interventional Radiology to step into the international medical circle. (authors)

  7. Prospective randomized trial of HDR brachytherapy as a sole modality in palliation of advanced esophageal carcinoma--an International Atomic Energy Agency study

    International Nuclear Information System (INIS)

    Sur, Ranjan K.; Levin, C. Victor; Donde, Bernard; Sharma, Vinay; Miszczyk, Leszek; Nag, Subir

    2002-01-01

    Background: Previous studies from South Africa have established that fractionated high-dose-rate (HDR) brachytherapy gives the best results in terms of palliation and survival in advanced esophageal cancer. A multicenter, prospective randomized study was therefore conducted under the auspices of the International Atomic Energy Agency to evaluate two HDR regimens. Methods and Materials: Surgically inoperable patients with histologically proven squamous cell cancer of the esophagus, tumor >5 cm in length on barium swallow and/or endoscopy, Karnofsky performance score >50, age 17-70 years, primary disease in the thoracic esophagus, no prior malignancy within the past 5 years, and any N or M status were included in the study. Exclusion criteria included cervical esophagus location, tumor extending 0.05). The overall survival was 7.9 months for the whole group (Group A, 9.1 months; Group B, 6.9 months; p>0.05). On univariate analysis, the presenting weight (p=0.0083), gender (p=0.0038), race (p=0.0105), the presenting dysphagia score (p=0.0083), the treatment center (p=0.0029), and tumor grade (p=0.0029) had an impact on the dysphagia-free survival, and gender (p=0.0011) and performance score (p=0.0060) had an impact on dysphagia-free survival on multivariate analysis. Only age had an impact on overall survival on both univariate (p=0.0430) and multivariate (p=0.0331) analysis. The incidence of strictures (Group A, n=12; Group B, n=13; p>0.05) and fistulas (Group A, n=11; Group B, n=12; p>0.05) was similar in both groups. Conclusion: Fractionated HDR brachytherapy alone is an effective method of palliating advanced esophageal cancers, surpassing the results of any other modality of treatment presently available. Dose fractions of 6 Gy x 3 and 8 Gy x 2 give similar results for dysphagia-free survival, overall survival, strictures, and fistulas and are equally effective in palliation of advanced esophageal cancer

  8. Procedures in diagnostic radiology

    International Nuclear Information System (INIS)

    Doyle, T.; Hare, W.S.C.; Thomson, K.; Tess, B.

    1989-01-01

    This book outlines the various procedures necessary for the successful practice of diagnostic radiology. Topics covered are: general principles, imaging of the urinary and gastrointestinal tracts, vascular radiology, arthrography, and miscellaneous diagnostic radiologic procedures

  9. Socioeconomic trends in radiology

    International Nuclear Information System (INIS)

    Barneveld Binkhuysen, F.H.

    1998-01-01

    For radiology the socioeconomic environment is a topic of increasing importance. In addition to the well-known important scientific developments in radiology such as interventional MRI, several other major trends can be recognized: (1) changes in the delivery of health care, in which all kinds of managed care are developing and will influence the practice of radiology, and (2) the process of computerization and digitization. The socioeconomic environment of radiology will be transformed by the developments in managed care, teleradiology and the integration of information systems. If radiologists want to manage future radiology departments they must have an understanding of the changes in the fields of economics and politics that are taking place and that will increasingly influence radiology. Some important and recognizable aspects of these changes will be described here. (orig.)

  10. Dental radiology

    International Nuclear Information System (INIS)

    Bhaskar, S.N.

    1982-01-01

    The book presents the radiological manifestations of the maxillodental region in a suitable manner for fast detection and correct diagnosing of diseases of the teeth, soft tissue, and jaws. Classification therefore is made according to the radiological manifestations of the diseases and not according to etiology. (orig./MG) [de

  11. White Paper: Curriculum in Interventional Radiology.

    Science.gov (United States)

    Mahnken, Andreas H; Bücker, Arno; Hohl, Christian; Berlis, Ansgar

    2017-04-01

    Purpose  Scope and clinical importance of interventional radiology markedly evolved over the last decades. Consequently it was acknowledged as independent subspecialty by the "European Union of Medical Specialists" (UEMS). Based on radiological imaging techniques Interventional Radiology is an integral part of Radiology. Materials und Methods  In 2009 the German Society for Interventional Radiology and minimally-invasive therapy (DeGIR) developed a structured training in Interventional Radiology. In cooperation with the German Society of Neuroradiology (DGNR) this training was extended to also cover Interventional Neuroradiology in 2012. Tailored for this training in Interventional Radiology a structured curriculum was developed, covering the scope of this modular training. Results  The curriculum is based on the DeGIR/DGNR modular training concept in Interventional Radiology. There is also an European Curriculum and Syllabus for Interventional Radiology developed by the "Cardiovascular and Interventional Radiological Society of Europe" (CIRSE). The presented curriculum in Interventional Radiology is designed to provide a uniform base for the training in Interventional Radiology in Germany, based on the competencies obtained during residency. Conclusion  This curriculum can be used as a basis for training in Interventional Radiology by all training sites. Key Points: · Interventional Radiology is an integral part of clinical radiology. · The German Society for Interventional Radiology and minimally-invasive therapy (DeGIR) developed a curriculum in Interventional Radiology. · This curriculum is an integrative basis for the training in interventional. Citation Format · Mahnken AH, Bücker A, Hohl C et al. White Paper: Curriculum in Interventional Radiology. Fortschr Röntgenstr 2017; 189: 309 - 311. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Does HDR Pre-Processing Improve the Accuracy of 3D Models Obtained by Means of two Conventional SfM-MVS Software Packages? The Case of the Corral del Veleta Rock Glacier

    Directory of Open Access Journals (Sweden)

    Álvaro Gómez-Gutiérrez

    2015-08-01

    Full Text Available The accuracy of different workflows using Structure-from-Motion and Multi-View-Stereo techniques (SfM-MVS is tested. Twelve point clouds of the Corral del Veleta rock glacier, in Spain, were produced with two different software packages (123D Catch and Agisoft Photoscan, using Low Dynamic Range images and High Dynamic Range compositions (HDR for three different years (2011, 2012 and 2014. The accuracy of the resulting point clouds was assessed using benchmark models acquired every year with a Terrestrial Laser Scanner. Three parameters were used to estimate the accuracy of each point cloud: the RMSE, the Cloud-to-Cloud distance (C2C and the Multiscale-Model-to-Model comparison (M3C2. The M3C2 mean error ranged from 0.084 m (standard deviation of 0.403 m to 1.451 m (standard deviation of 1.625 m. Agisoft Photoscan overcome 123D Catch, producing more accurate and denser point clouds in 11 out 12 cases, being this work, the first available comparison between both software packages in the literature. No significant improvement was observed using HDR pre-processing. To our knowledge, this is the first time that the geometrical accuracy of 3D models obtained using LDR and HDR compositions are compared. These findings may be of interest for researchers who wish to estimate geomorphic changes using SfM-MVS approaches.

  13. SU-C-BRD-02: A Team Focused Clinical Implementation and Failure Mode and Effects Analysis of HDR Skin Brachytherapy Using Valencia and Leipzig Surface Applicators

    International Nuclear Information System (INIS)

    Sayler, E; Harrison, A; Eldredge-Hindy, H; Dinome, J; Munro, S; Anne, R; Comber, E; Lockamy, V

    2014-01-01

    Purpose: and Leipzig applicators (VLAs) are single-channel brachytherapy surface applicators used to treat skin lesions up to 2cm diameter. Source dwell times can be calculated and entered manually after clinical set-up or ultrasound. This procedure differs dramatically from CT-based planning; the novelty and unfamiliarity could lead to severe errors. To build layers of safety and ensure quality, a multidisciplinary team created a protocol and applied Failure Modes and Effects Analysis (FMEA) to the clinical procedure for HDR VLA skin treatments. Methods: team including physicists, physicians, nurses, therapists, residents, and administration developed a clinical procedure for VLA treatment. The procedure was evaluated using FMEA. Failure modes were identified and scored by severity, occurrence, and detection. The clinical procedure was revised to address high-scoring process nodes. Results: Several key components were added to the clinical procedure to minimize risk probability numbers (RPN): -Treatments are reviewed at weekly QA rounds, where physicians discuss diagnosis, prescription, applicator selection, and set-up. Peer review reduces the likelihood of an inappropriate treatment regime. -A template for HDR skin treatments was established in the clinical EMR system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planning physicist, and increases the detectability of an error during the physics second check. -A screen check was implemented during the second check to increase detectability of an error. -To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display. This facilitates data entry and verification. -VLAs are color-coded and labeled to match the EMR prescriptions, which simplifies in-room selection and verification. Conclusion: Multidisciplinary planning and FMEA increased delectability and

  14. Radiological protection

    International Nuclear Information System (INIS)

    Azorin N, J.; Azorin V, J. C.

    2010-01-01

    This work is directed to all those people related with the exercise of the radiological protection and has the purpose of providing them a base of knowledge in this discipline so that they can make decisions documented on technical and scientist factors for the protection of the personnel occupationally exposed, the people in general and the environment during the work with ionizing radiations. Before de lack of a text on this matter, this work seeks to cover the specific necessities of our country, providing a solid presentation of the radiological protection, included the bases of the radiations physics, the detection and radiation dosimetry, the radiobiology, the normative and operational procedures associates, the radioactive wastes, the emergencies and the transport of the radioactive material through the medical and industrial applications of the radiations, making emphasis in the relative particular aspects to the radiological protection in Mexico. The book have 16 chapters and with the purpose of supplementing the given information, are included at the end four appendixes: 1) the radioactive waste management in Mexico, 2-3) the Mexican official standards related with the radiological protection, 4) a terms glossary used in radiological protection. We hope this book will be of utility for those people that work in the investigation and the applications of the ionizing radiations. (Author)

  15. Radiology trainer. Musculoskeletal system

    International Nuclear Information System (INIS)

    Staebler, A.; Erlt-Wagner, B.

    2006-01-01

    This book enables students to simulate examinations. The Radiology Trainer series comprises the whole knowledge of radiology in the form of case studies for self-testing. It is based on the best-sorted German-language collection of radiological examinations of all organ regions. Step by step, radiological knowledge is trained in order to make diagnoses more efficient. The book series ensures optimal preparation for the final medical examinations and is also a valuable tool for practical training. (orig.)

  16. Computed versus measured response of HDR reactor building in large scale shaking tests

    International Nuclear Information System (INIS)

    Werkle, H.; Waas, G.

    1987-01-01

    The earthquake resistant design of NPP structures and their installations is commonly based on linear analysis methods. Nonlinear effects, which may occur during strong earthquakes, are approximately accounted for in the analysis by adjusting the structural damping values. Experimental investigations of nonlinear effects were performed with an extremely heavy shaker at the decommissioned HDR reactor building in West Germany. The tests were directed by KfK (Nuclear Research Center Karlsruhe, West Germany) and supported by several companies and institutes from West Germany, Switzerland and the USA. The objective was the dynamic repsonse behaviour of the structure, piping and components to strong earthquake-like shaking including nonlinear effects. This paper presents some results of safety analyses and measurements, which were performed prior and during the test series. It was intended to shake the building up to a level where only a marginal safety against global structural failure was left

  17. Dosimetric measurements of an 192Ir HDR source with a diamond detector

    International Nuclear Information System (INIS)

    Rustgi, Surendra N.

    1996-01-01

    Purpose: To study the feasibility of using a diamond detector for the dosimetry of a high dose rate (HDR) 192 Ir source and to compare the measurement results with published data and calculations from a commercial treatment planning system. Materials and methods: The sensitive volume of the diamond detector consists of a disk of 0.26 mm thickness and 3 mm diameter. The detector was applied an external bias of +100 V and was preirradiated to a dose of 500 cGy to stabilize its response. The 192 Ir source from the Nucletron microSelectron unit has an active diameter of 0.6 mm and a length of 3.5 mm. Photon fluence anisotropy factors in air were measured at distances of 5 and 10 cm from two sources and compared with TLD measurements. Dose profiles and isodose distributions were measured at several distances from the source and compared with calculations from a Nucletron treatment planning system. These dose calculations in water use a point source approximation with the anisotropy factors independent of the radial distance from the source. Results: The photon fluence around the 192 Ir HDR source, measured with a diamond detector at distances of 5 and 10 cm from the source, is very anisotropic. Compared to the source transverse direction, the photon fluence intensity along the source axis reduces to approximately 60%. Measurements performed on two sources indicate that the photon anisotropy does not change with distance in air. Within experimental uncertainty, similar results were obtained with TLD rods and are in excellent agreement with published anisotropy factors 1 . Dose profiles, measured with the diamond detector in a water phantom, at distances of 1,2,3 and 5 cm from the source, are found to be in excellent agreement with the Nucletron planning system calculations. Similar excellent agreement is observed between the measured and calculated isodose curves in planes parallel to the source plane. Conclusion: The diamond detector has been demonstrated to be suitable

  18. Radiology and social media: are private practice radiology groups more social than academic radiology departments?

    Science.gov (United States)

    Glover, McKinley; Choy, Garry; Boland, Giles W; Saini, Sanjay; Prabhakar, Anand M

    2015-05-01

    This study assesses the prevalence of use of the most commonly used social media sites among private radiology groups (PRGs) and academic radiology departments (ARDs). The 50 largest PRGs and the 50 ARDs with the highest level of funding from the National Institutes of Health were assessed for presence of a radiology-specific social media account on Facebook, Twitter, Instagram, Pinterest, YouTube, and LinkedIn. Measures of organizational activity and end-user activity were collected, including the number of posts and followers, as appropriate; between-group comparisons were performed. PRGs adopted Facebook 12 months earlier (P = .02) and Twitter 18 months earlier (P = .02) than did ARDs. A total of 76% of PRGs maintained ≥1 account on the social media sites included in the study, compared with 28% of ARDs (P Instagram, 2%. The prevalence of radiology-specific social media accounts for ARDs was: Facebook, 18%; LinkedIn, 0%; Twitter, 24%; YouTube, 6%; Pinterest, 0%; and Instagram, 0%. There was no significant difference between ARDs and PRGs in measures of end-user or organizational activity on Facebook or Twitter. Use of social media in health care is emerging as mainstream, with PRGs being early adopters of Facebook and Twitter in comparison with ARDs. Competitive environments and institutional policies may be strong factors that influence how social media is used by radiologists at the group and department levels. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  19. Radiological diagnostics in hyperparathyroidism

    International Nuclear Information System (INIS)

    Moedder, U.; Kuhn, F.P.; Gruetzner, G.

    1991-01-01

    The most important radiologically detectable effects of the primary and secondary hyperparathyroidism of the skeletal system and the periarticular soft tissue structures are presented. In the following sensitivity and specificity of radiological imaging - sonography, scintigraphy, computed tomography, magnetic resonance imaging, arteriography and selective venous sampling - in the preoperative diagnostic of the parathyroid adenomas are discussed. Therefore, radiological imaging can be omitted before primary surgery. It was only in secondary surgery that radiological process proved useful and a guide during surgical intervention. (orig.) [de

  20. Assessment of radiological protection systems among diagnostic radiology facilities in North East India.

    Science.gov (United States)

    Singh, Thokchom Dewan; Jayaraman, T; Arunkumar Sharma, B

    2017-03-01

    This study aims to assess the adequacy level of radiological protection systems available in the diagnostic radiology facilities located in three capital cities of North East (NE) India. It further attempts to understand, using a multi-disciplinary approach, how the safety codes/standards in diagnostic radiology framed by the Atomic Energy Regulatory Board (AERB) and the International Atomic Energy Agency (IAEA) to achieve adequate radiological protection in facilities, have been perceived, conceptualized, and applied accordingly in these facilities. About 30 diagnostic radiology facilities were randomly selected from three capitals of states in NE India; namely Imphal (Manipur), Shillong (Meghalaya) and Guwahati (Assam). A semi-structured questionnaire developed based on a multi-disciplinary approach was used for this study. It was observed that radiological practices undertaken in these facilities were not exactly in line with safety codes/standards in diagnostic radiology of the AERB and the IAEA. About 50% of the facilities had registered/licensed x-ray equipment with the AERB. More than 80% of the workers did not use radiation protective devices, although these devices were available in the facilities. About 85% of facilities had no institutional risk management system. About 70% of the facilities did not carry out periodic quality assurance testing of their x-ray equipment or surveys of radiation leakage around the x-ray room, and did not display radiation safety indicators in the x-ray rooms. Workers in these facilities exhibited low risk perception about the risks associated with these practices. The majority of diagnostic radiology facilities in NE India did not comply with the radiological safety codes/standards framed by the AERB and IAEA. The study found inadequate levels of radiological protection systems in the majority of facilities. This study suggests a need to establish firm measures that comply with the radiological safety codes/standards of the

  1. Variations of intracavitary applicator geometry during multiple HDR brachytherapy insertions in carcinoma cervix and its influence on reporting as per ICRU report 38

    International Nuclear Information System (INIS)

    Datta, Niloy Ranjan; Kumar, Shaleen; Das, Koilpillai Joseph Maria; Pandey, Chandra Mani; Halder, Shikha; Ayyagari, Sunder

    2001-01-01

    Purpose: This paper examines the extent of variation in the applicator geometry during multiple high dose rate (HDR) intracavitary brachytherapy (ICBT) applications and its impact on reporting as per ICRU report 38. Materials and methods: Eighty orthogonal radiographs from 20 consecutive patients of carcinoma cervix (FIGO stages, IIA-IIIB) having four HDR ICBT applications of 6 Gy each at weekly intervals following teletherapy were evaluated. The applicator consisted of a flexible intrauterine tandem (IUT) independent of the ovoid assembly. The applicator geometry was evaluated in terms of: α angle, β angle, intrauterine length (IUTL), interovoid (IOV), os to right ovoid (ORT) and os to left ovoid (OLT) distances along with vertical (VDL) and anteroposterior displacements (ADL) of the os with respect to the ovoids. The Cartesian co-ordinates (X, Y, and Z) of the IUT tip, centre of both ovoids and os were also measured. Doses to right point A (ARD), left point A (ALD), along with a reference volume of 6 Gy for ICRU height (IRH), width (IRW), thickness (IRT) and volume (IRV) were estimated for each application. Results: Highly significant differences (P<0.001) between four insertions in any given patient across 20 patients for α angle, β angle, IUTL, IOV, ORT, VDL, co-ordinates of the IUT, ovoids and os were observed, except for ADL (P=0.041) and OLT (P=0.247). As a consequence, variations were observed in ARD (P=0.027), ALD (P=0.017); IRH, IRW, IRT and IRV (all P<0.001). Applicator factors which influenced the various dose specification parameters were: β angle and ORT for both ARD and ALD; UTLN, VDL and ORT for IRH; UTLN and IOV for IRW; UTLN for IRT and VDL for the 6 Gy IRV. Conclusions: A significant variation of the applicator geometry and its movement was observed in patients undergoing multiple HDR ICBT. This could have implications for reporting dose and volume specifications as required by ICRU report 38

  2. Pediatric radiology

    International Nuclear Information System (INIS)

    Benz-Bohm, G.

    1997-01-01

    Pediatric radiology is an important subsection of diagnostic radiology involving specific difficulties, but unfortunately is quite too often neglected as a subject of further education and training. The book therefore is not intended for specialists in the field, but for radiologists wishing to plunge deeper into the matter of pediatric radiology and to acquire a sound, basic knowledge and information about well-proven modalities, the resulting diagnostic images, and interpretation of results. The book is a compact guide and a helpful source of reference and information required for every-day work, or in special cases. With patients who are babies or children, the challenges are different. The book offers all the information needed, including important experience from pediatric hospital units that may be helpful in diagnostic evaluation, information about specific dissimilarities in anatomy and physiology which affect the imaging results, hints for radiology planning and performance, as well as information about the various techniques and their indication and achievements. The book presents a wide spectrum of informative and annotated images. (orig./CB) [de

  3. Attention for pediatric interventional radiology

    International Nuclear Information System (INIS)

    Zhu Ming; Cheng Yongde

    2005-01-01

    Radiological interventions possess wide utilization in the diagnosis and treatment for pediatric patients. Pediatric interventional radiology is an important branch of interventional radiology and also an important branch of pediatric radiology. Pediatric interventional radiology has grown substantially over the last 30 years, radiologists closely cooperation with surgeons and other physicians providing a new horizon in the management of pediatric diseases in western countries. It includes pediatric cardiac interventional radiology, pediatric neuro-interventional radiology, pediatric vascular interventional radiology, pediatric nonvascular interventional radiology, pediatric tumor interventional radiology and others. In the United States, every children hospital which owns two hundred beds has to have special trained interventional radiologists in radiologic department installing with advanced digital subtraction angiographic equipment. Interventional therapeutic procedures and diagnostic angiography have been proceeding more and more for the congenital and acquired diseases of children. The promising results give use uprising and interventional therapy as an alternative or a replacement or supplement to surgical operation. Pediatric interventional radiology is rather underdeveloped in China with a few special pediatric interventional radiologist, lack of digital subtraction angiography equipment. Pediatric radiologists have no enough field for interventional procedures such as pediatric neuro-interventional radiology and pediatric vascular interventional radiology. In the contrary adult interventional radiologists do have better interventional jobs in China and Pediatric cardiologists also share the same trend. They perform angiocardiography for congenital heart diseases and treat congenital heart disease with interventional procedures including balloon dilation of valves and vessels, coil embolization of collaterals, patent ducts and other arterial fistulae

  4. Radiological evaluation of dysphagia

    Energy Technology Data Exchange (ETDEWEB)

    Ott, D.J.; Gelfand, D.W.; Wu, W.C.; Chen, Y.M.

    1986-11-21

    Dysphagia is a common complaint in patients presenting for radiological or endoscopic examination of the esophagus and is usually due to functional or structural abnormalities of the esophageal body or esophagogastric region. The authors review the radiological evaluation of the esophagus and esophagogastric region in patients with esophageal dysphagia and discuss the roentgenographic techniques used, radiological efficacy for common structural disorders, and evaluation of esophageal motor function. Comparison is made with endoscopy in assessing dysphagia, with the conclusion that the radiological examination be used initially in patients with this complaint.

  5. Radiological evaluation of dysphagia

    International Nuclear Information System (INIS)

    Ott, D.J.; Gelfand, D.W.; Wu, W.C.; Chen, Y.M.

    1986-01-01

    Dysphagia is a common complaint in patients presenting for radiological or endoscopic examination of the esophagus and is usually due to functional or structural abnormalities of the esophageal body or esophagogastric region. The authors review the radiological evaluation of the esophagus and esophagogastric region in patients with esophageal dysphagia and discuss the roentgenographic techniques used, radiological efficacy for common structural disorders, and evaluation of esophageal motor function. Comparison is made with endoscopy in assessing dysphagia, with the conclusion that the radiological examination be used initially in patients with this complaint

  6. A project: 'Radiological protection in radiology', IAEA - Universidad Central de Venezuela

    International Nuclear Information System (INIS)

    Diaz, A.R.; Salazar, G.; Fermin, R.; Gonzalez, M.

    2001-01-01

    For several years a reference center of the UCV has been working on the project VEN/9/007 on dose reduction in diagnostic radiology sponsored by the IAEA. The dose and quality image was evaluated for different types of radiological study (conventional radiology, CT, mammography, interventional radiology) in different facilities at Caracas and others regions of the Venezuela. TL dosimeters were used to assess dose and reduction in dose. Based on the recommendations given by CEC documents on diagnostic quality criteria, a quality control program in radiological protection of patients and staff has been developed, for example: Pilot study by using TLD in personnel radiation monitoring. Comparative study between high and low kVp in chest. Evaluation and dose reduction in chest pediatric. Reduction of radiation dose in studies of billiards via Quality Image and reduction of the dose in studies of colon by enema. Radiation dose of staff in fluoroscopy procedures. Evaluation and dose reduction in dental radiography in public Institutions. A mammography accreditation program for Venezuela, applied to public hospitals. (author)

  7. Radiological Evaluation Standards in the Radiology Department of Shahid Beheshti Hospital (RAH) YASUJ Based on Radiology standards in 92

    OpenAIRE

    A َKalantari; SAM Khosravani

    2014-01-01

    Background & aim: Radiology personnel’s working in terms of performance and safety is one of the most important functions in order to increase the quality and quantity. This study aimed to evaluate the radiological standards in Shahid Beheshti Hospital of Yasuj, Iran, in 2013. Methods: The present cross-sectional study was based on a 118 randomly selected graphs and the ranking list, with full knowledge of the standards in radiology was performed two times. Data were analyzed using descri...

  8. SHAM: High-level seismic tests of piping at the HDR

    International Nuclear Information System (INIS)

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Malcher, L.; Schrammel, D.; Steinhilber, H.; Costello, J.F.

    1988-01-01

    As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level simulated seismic tests (SHAM) were performed during April--May 1988 on the VKL (Versuchskreislauf) in-plant piping system with two servohydraulic actuators, each capable of generating 40 tons of force. The purpose of these experiments was to study the behavior of piping subjected to seismic excitation levels that exceed design levels manifold and may result in failure/plastification of pipe supports and pipe elements, and to establish seismic margins for piping and pipe supports. The performance of six different dynamic pipe support systems was compared in these tests and the response, operability, and fragility of dynamic supports and of a typical US gate valve were investigated. Data obtained in the tests are used to validate analysis methods. Very preliminary evaluations lead to the observation that, in general, failures of dynamic supports (in particular snubbers) occur only at load levels that substantially exceed the design capacity. Pipe strains at load levels exceeding the design level threefold are quite small, and even when exceeding the design level eightfold are quite tolerable. Hence, under seismic loading, even at extreme levels and in spite of multiple support failures, pipe failure is unlikely. 5 refs., 16 figs

  9. SU-G-201-07: Dosimetric Verification of a 3D Printed HDR Skin Brachytherapy Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, K; Stanley, D; Eng, T; Kirby, N; Gutierrez, A; Stathakis, S; Papanikolaou, N [University of Texas HSC SA, San Antonio, TX (United States); Baumgarten, A; Pelletier, C; Jung, J; Feng, Y; Huang, Z; Ju, A [East Carolina University, Greenville, NC (United States); Corbett, M [Greenville Health System, Greenville, SC (United States)

    2016-06-15

    Purpose: The use of radiation as a treatment modality for skin cancer has increased significantly over the last decade with standardized applicators. Utilizing 3D printing, the ability to make applicators specifically designed for each patient’s anatomy has become economically feasible. With this in mind it was the aim of this study to determine the dosimetric accuracy of a 3-D printed HDR brachytherapy applicator for the skin. Methods: A CT reference image was used to generate a custom applicator based on an anthropomorphic head and neck phantom. To create the applicator a 1cm expansion anteriorly with 0.5cmX0.5cm trenches on the outer surface that were spaced 1cm sup-inf to accommodate standard 6F flexible catheters. The applicator was printed using PLA material using a printrbot simple printer. A treatment plan optimized to deliver a clinically representative volume was created in Oncentra and delivered with a nucletron afterloader. Measurements were made using TLDs and EBT3 gafchromic film that were placed between the applicator and the phantom’s forehead. An additional piece of film was also used to qualitatively asses the dose distribution in the transverse plane. Using a standard vaginal cylinder and bolus, a standardized curve correlating TLD and film exposure-to-radiation dose was established by irradiating film to known doses (200,500,700 cGy) at a 3.5 cm radius distance. Results: Evaluated TLDs showed the absolute dose delivered to the skin surface using the 3-D printed bolus was 615cGy±6%, with a mean predicted TPS value in the measured area of 617.5±7%. Additionally, planar dose distributions had good qualitative agreement with calculated TPS isodoses. Conclusion: This work demonstrates patient specific 3-D printed HDR brachytherapy applicators for skin cancer treatments are practical and accurate in TPS calculations but additional measurements are needed to verify additional sites and dose at depth.

  10. SU-G-201-07: Dosimetric Verification of a 3D Printed HDR Skin Brachytherapy Applicator

    International Nuclear Information System (INIS)

    Rasmussen, K; Stanley, D; Eng, T; Kirby, N; Gutierrez, A; Stathakis, S; Papanikolaou, N; Baumgarten, A; Pelletier, C; Jung, J; Feng, Y; Huang, Z; Ju, A; Corbett, M

    2016-01-01

    Purpose: The use of radiation as a treatment modality for skin cancer has increased significantly over the last decade with standardized applicators. Utilizing 3D printing, the ability to make applicators specifically designed for each patient’s anatomy has become economically feasible. With this in mind it was the aim of this study to determine the dosimetric accuracy of a 3-D printed HDR brachytherapy applicator for the skin. Methods: A CT reference image was used to generate a custom applicator based on an anthropomorphic head and neck phantom. To create the applicator a 1cm expansion anteriorly with 0.5cmX0.5cm trenches on the outer surface that were spaced 1cm sup-inf to accommodate standard 6F flexible catheters. The applicator was printed using PLA material using a printrbot simple printer. A treatment plan optimized to deliver a clinically representative volume was created in Oncentra and delivered with a nucletron afterloader. Measurements were made using TLDs and EBT3 gafchromic film that were placed between the applicator and the phantom’s forehead. An additional piece of film was also used to qualitatively asses the dose distribution in the transverse plane. Using a standard vaginal cylinder and bolus, a standardized curve correlating TLD and film exposure-to-radiation dose was established by irradiating film to known doses (200,500,700 cGy) at a 3.5 cm radius distance. Results: Evaluated TLDs showed the absolute dose delivered to the skin surface using the 3-D printed bolus was 615cGy±6%, with a mean predicted TPS value in the measured area of 617.5±7%. Additionally, planar dose distributions had good qualitative agreement with calculated TPS isodoses. Conclusion: This work demonstrates patient specific 3-D printed HDR brachytherapy applicators for skin cancer treatments are practical and accurate in TPS calculations but additional measurements are needed to verify additional sites and dose at depth.

  11. Highly cited works in radiology: the top 100 cited articles in radiologic journals.

    Science.gov (United States)

    Pagni, Matthew; Khan, Nickalus R; Cohen, Harris L; Choudhri, Asim F

    2014-08-01

    The number of citations a publication receives can be used to show its impact on a field of study. It may indicate the educational interest in a given population or underline a perceived or real educational gap. This article identifies and characterizes the 100 top cited publications in radiologic journals as of May 2013. All clinical radiologic journals listed by Thomson Reuters Journal Citation Reports in 2011 were identified. A total of 46 journals were identified, and all articles published within these journals were analyzed for citation counts. The top 100 highly cited articles were recorded. The most frequently cited radiologic articles appeared in 9 of the 46 journals. These included 59 articles in Radiology, 17 in Journal of Nuclear Medicine, 9 in the American Journal of Roentgenology, 5 in the British Journal of Radiology, 4 in Investigative Radiology, 2 in American Journal of Neuroradiology, 2 in European Radiology, 2 in Radiologic Clinics of North America, 1 in the Seminars in Nuclear Medicine, and 1 in Pediatric Radiology. The citation values ranged from 422 to 7506 with a mean of 751. Publication dates ranged from 1967 to 2006 with the 5-year period between 1986 and 1990 accounting for the largest percentage of articles. The most frequently studied radiologic modality was magnetic resonance imaging (MRI; 28 articles), followed by vascular/interventional (19 articles) and nuclear medicine (13 articles). The central nervous system was the most frequently studied organ system (22 articles), followed by mixed organ systems (14 articles) and liver (12 articles). The top cited articles in radiologic journals span a wide range of imaging modalities, subspecialties, and organ systems. Topics that occurred frequently in the top 100 cited articles included contrast and radiopharmaceutical characterization, MRI of motion, percutaneous radiofrequency ablation in the liver and percutaneous vertebroplasty. We present a methodology that uses citation analysis to

  12. Characterization of commercial MOSFET detectors and their feasibility for in-vivo HDR brachytherapy.

    Science.gov (United States)

    Phurailatpam, Reena; Upreti, Rituraj; Nojin Paul, Siji; Jamema, Swamidas V; Deshpande, Deepak D

    2016-01-01

    The present study was to investigate the use of MOSFET as an vivo dosimeter for the application of Ir-192 HDR brachytherapy treatments. MOSFET was characterized for dose linearity in the range of 50-1000 cGy, depth dose dependence from 2 to 7 cm, angular dependence. Signal fading was checked for two weeks. Dose linearity was found to be within 2% in the dose range (50-1000 cGy). The response varied within 8.07% for detector-source distance of 2-7 cm. The response of MOSFET with the epoxy side facing the source (0 degree) is the highest and the lowest response was observed at 90 and 270 degrees. Signal was stable during the study period. The detector showed high dose linearity and insignificant fading. But due to angular and depth dependence, care should be taken and corrections must be applied for clinical dosimetry. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. 3D dosimetry in HDR brachytherapy resonance imaging nuclear magnetic (b= 0.2 t) using a base acrylic gel (MAGIC)

    International Nuclear Information System (INIS)

    Batista Hernandez, Guillermo; Velez, Graciela R.; Schurrer, Clemar

    2009-01-01

    Dosimetry gels using magnetic resonance imaging (MRI) has been extended in recent literature. Our study presents the preparation, calibration IRM of acrylic gel (MAGIC) and its application in measuring dose in a 3D distribution HDR Brachytherapy with 192Ir source. The first gels used were the type Fricke gels based on the relationship of dose and time T1 relaxation. In 2001, Fong presented a new normoxic gel known as MAGIC whose main components are Methacrylic Acid (polymerizing), and Hydroquinone (inhibitor of self-curing) based on the relationship of dose and T2 relaxation time. Subsequent studies make changes in the concentrations component of the MAGIC (Methacrylic Acid and Hydroquinone in particular) to observe the behavior of the sensitivity of the gel with respect to its components and beam magnetic resonance equipment using magnetic fields higher to 0.5 T. This is done with equipment available to the staff of a Radiotherapy clinic setting. MAGIC gel is prepared according to composition by Crescenti (6% methacrylic acid), is calibrated with a 60Co unit TERADI INVAP 8002c (Argentina). Was raised shooting in a Siemens MRI scanner of 0.2 T Magnetom Concerto irradiated with a team of Brachytherapy High Dose Rate (HDR) Micro selectron Nucletron's V2 HDR for comparison with dose distributions provided by the planning system from Nucletron PLATO Sunrise. Was obtained a calibration curve for doses ranging from 0 to 8.0 Gy and a field strength 0.2 T magnetic We compared the sensitivity obtained in our calibration (Slope of the calibration curve) with those presented in the literature. Two phantoms were prepared for measurement in brachytherapy: a PMMA and a PVC. It was noted that MAGIC gel reacts chemically with PMMA and cured prior to irradiation. The phantom of PVC (no reactions) were irradiated with Micro selectron equipment and measured the dose distribution in 3D MRI. Were measured doses at the points specified by the Planning System and PLATO Sunrise compared

  14. Verification of the HDR-test V44 using the computer program RALOC-MOD1/83

    International Nuclear Information System (INIS)

    Jahn, H.; Pham, T. v.; Weber, G.; Pham, B.T.

    1985-01-01

    RALOC-MOD1/83 was extended by a drainage and sump level modul and several component models to serve as a containment systems code for various LWR types. One such application is to simulate the blowdown in a full pressure containment which is important for the short and long term hydrogen distribution. The post test calculation of the containment standard problem experiment HDR-V44 shows a good agreement, to the test data. The code may be used for short and long term predictions, but it was learned that double containments need the representation of the gap between the inner and outer shell into several zones to achieve a good long-term temperature prediction. The present work completes the development, verification and documentation of RALOC-MOD1. (orig.) [de

  15. Radiological Worker Training: Radiological Worker 2 lesson plans

    International Nuclear Information System (INIS)

    1992-10-01

    Upon completion of this g course, the participant will have the knowledge to work safely in areas controlled for a radiological purposes using proper radiological practices. The participant will be able toidentify the fundamentals of radiation, radioactive material and radioactive contamination includes identify the three basic particles of an atom, define ionization, define ionizing radiation, radioactive material and radioactive contamination, distinguish between ionizing radiation and non-ionizing radiation, define radioactivity and radioactive half-life

  16. HDR-investigations of check valve closure and resultant water hammer effects

    International Nuclear Information System (INIS)

    Scholl, K.D.

    1983-01-01

    The presented investigations are based on the Loss of Coolant Accident (LOCA). They concentrate on the first blowdown phase after pipe break of a feedwater line. The effect of such a break is moderated by quick closing check valves, by which the loss of coolant water is reduced and optimal post accident conditions are obtained. Unfortunately the closure of the valve can cause high pressure peaks (water hammer effects) in the feedwater system which potentially could produce safety relevant secondary damage. The system loading by these effects has been analysed. The HDR-Investigation-results led to an improvement of the feedwater system safety by verifying damping measures of quick closing check valves. Pressure peaks obtained with undamped valves in the range of 300 bars, are reduced to zero or a few bars above the normal operation pressure in feedwater systems. For the analytical simulation of valve closure the following dominant acting forces are identified: the blowdown flow resistance of the valve cone and the damping pistong force. The analytical description and quantification of the forces depends on blowdown flow and valve friction parameters. These have been evaluated and are presented for practical use. (orig.)

  17. Rectal doses during LDR and HDR intracavitary brachytherapy of gyneacological malignancies: comparison of direct measurement with that of calculated from radiograph

    International Nuclear Information System (INIS)

    Chougule, Arun; Agarwal, D.P.

    2001-01-01

    In the present study rectal doses using CaSO 4 :Dy powder has been measured in 14 cases of cancer cervix treated by LDR brachytherapy and 20 cases of cancer cervix treated by HDR brachytherapy. The maximum rectal dose in LDR varied from 1073-1856 cGy for point A dose of 3000 cGy. The maximum rectal dose was found to be at 6-8 cm from the anal verge. The results of the calculation and actual measurements has been compared

  18. Radiological interpretation: The 'step-child' in radiology

    International Nuclear Information System (INIS)

    Heilmann, H.P.

    1981-01-01

    Radiology has a highly developed technique, an extensive scientific literature and is excellent for acquiring information; one must contrast with this the difficulties in interpreting the information. In an attempt to find the reason for this, the process of radiological interpretation has been scrutinised. Critical consideration has been given to errors in the interpretation of the findings and to problems arising from the use of the available data. An attempt is made, with the help of diagrams, to determine a pathway for further development of information handling in X-ray diagnosis. (orig.) [de

  19. Rational use of diagnostic radiology

    International Nuclear Information System (INIS)

    Racoveanu, N.T.; Volodin, V.

    1992-01-01

    The escalating number of radiodiagnostic investigations has, as a consequence, an increase in medical irradiation of patients and of cost of radiological services. Radiologists in USA and UK have since early 1970 questioned the efficacy of various radiological investigations and produced substantial evidence that more rational approaches are necessary. WHO initiated, in 1977, a programme in this direction which has issued four technical reports which give practical recommendations on how to rationalize the use of radiological examinations. Three main directions are considered: (1) Abandonment of routine radiological examinations, as procedures with no clinical or epidemiologic significance and which represent a waste of resources and patient dose. (2) Patient selection for various radiological investigations based on clinical criteria (high, intermediate, low yield). Selected patients have an increased prevalence of the given disease and the predictive value of radiological investigation is much higher. (3) Use of diagnostic algorithms with higher cost/efficiency and risk/benefit ratios, improving the outcome of radiological examinations

  20. Is there any advantage of CT based 3-dimensional conformal planning over conventional orthogonal x-ray based planning in HDR brachytherapy in breast cancer

    International Nuclear Information System (INIS)

    Biswal, B.M.; Idris, N.R.; Zakaria, A.B.; Khairul, N.

    2003-01-01

    The conventional brachytherapy dose calculation is based on a particular brachytherapy rule or individual dosimetry based on the reconstruction of the sources from the orthogonal films. In the recent years many centers are using CT based 3D conformal brachytherapy in order to improve the dosimetric outcome of a given plan. Here we would like to present our experience on the use of both techniques to deliver HDR interstitial brachytherapy as boost in early breast cancer. From January 2001 to January 2003, we treated 4 breast cancer patients using conventional orthogonal x-rays and CT scan in 3 cases for the treatment plan. All patients received an external beam radiotherapy dose of 46 Gy in 23 fractions over 4.5 weeks to the whole breast using 6 MV photon beam. Subsequently the primary lesion was supplimented with HDR brachytherapy to a dose of 2.5 Gy BID for 3 consecutive days using a (192)Ir microSelectronHDR. The dose prescription was individualized to encompass the tumor volume with a 10 mm margin. The differences of the dosimetric outcome were compared. All patients completed above schedule of radiotherapy. The primary was implanted with single plane in 3 patients and multiplane implant in 4 patients. Orthogonal x-ray based localization was performed in 4 patients and CT scan based localization in 3 cases. Three patients were implanted single plane and 4 patients with multiplane implants with a median catheter number of 9 (range 6-14). The 3D conformal dose optimization was performed using Nucletron planning system (Plato). The mean 100% and 150% isodose volume was 67.3 cm 3 and 31.25cm 3 respectively. The identification of primary tumor volume, organ at risk, and identification of afterloading catheters were superior in CT based plan than conventional planning. CT scan based 3D conformal brachytherapy planning give better identification of tumor volume and its curvature, decrease the time to identify the sources and evaluate the radiation dose to organs at

  1. SU-F-T-14: Dosimetric Impacts of Various Uncertainties in Cervical Cancer HDR Brachytherapy: Are Conventional Point Doses Good Surrogates for 3D Dosimetry?

    Energy Technology Data Exchange (ETDEWEB)

    Liang, X; Li, Z [University of Florida Health Proton Therapy Institute, Jacksonville, FL (United States); Zheng, D [University of Nebraska Medical Center, Omaha, NE (United States); Zhang, X; Narayanasamy, G; Morrill, S; Penagaricano, J; Paudel, N [University of Arkansas for Medical Sciences, Little Rock, AR (United States)

    2016-06-15

    Purpose: In the context of evaluating dosimetric impacts of a variety of uncertainties involved in HDR Tandem-and-Ovoid treatment, to study the correlations between conventional point doses and 3D volumetric doses. Methods: For 5 cervical cancer patients treated with HDR T&O, 150 plans were retrospectively created to study dosimetric impacts of the following uncertainties: (1) inter-fractional applicator displacement between two treatment fractions within a single insertion by applying Fraction#1 plan to Fraction#2 CT; (2) positional dwell error simulated from −5mm to 5mm in 1mm steps; (3) simulated temporal dwell error of 0.05s, 0.1s, 0.5s, and 1s. The original plans were based on point dose prescription, from which the volume covered by the prescription dose was generated as the pseudo target volume to study the 3D target dose effect. OARs were contoured. The point and volumetric dose errors were calculated by taking the differences between original and simulated plans. The correlations between the point and volumetric dose errors were analyzed. Results: For the most clinically relevant positional dwell uncertainty of 1mm, temporal uncertainty of 0.05s, and inter-fractional applicator displacement within the same insertion, the mean target D90 and V100 deviation were within 1%. Among these uncertainties, the applicator displacement showed the largest potential target coverage impact (2.6% on D90) as well as the OAR dose impact (2.5% and 3.4% on bladder D2cc and rectum D2cc). The Spearman correlation analysis shows a correlation coefficient of 0.43 with a p-value of 0.11 between target D90 coverage and H point dose. Conclusion: With the most clinically relevant positional and temporal dwell uncertainties and patient interfractional applicator displacement within the same insertion, the dose error is within clinical acceptable range. The lack of correlation between H point and 3D volumetric dose errors is a motivator for the use of 3D treatment planning in

  2. Occupational exposure in interventional radiology

    International Nuclear Information System (INIS)

    Oh, H.J.; Lee, K.Y.; Cha, S.H.; Kang, Y.K.; Kim, H.J.; Oh, H.J.

    2003-01-01

    This study was conducted to survey of radiation safety control and to measure occupational radiation exposure dose of staff in interventional radiology in Korea. Interventioanl radiology requires the operator and assisting personnel to remain close to the patient, and thus close to primary beams of radiation. Therefore exposure doses of these personnel are significant from a radiological protection point of view. We surveyed the status of radiation safety on interventional radiology of 72 hospitals. The result were that 119 radiation equipments are using in interventional radiology and 744 staffs are composed of 307 radiologists, 116 residents of radiology, 5 general physicians, 171 radiologic technologists and 145 nurses. 81.4% and 20.2 % of operating physicians are using neck collar protector and goggle respectively. The average radiation dose was measured 0.46±0.15 mSv/10 hours fluoroscopy inside examination room in radiation protection facilities. Occupational radiation exposure data on the staff were assessed in interventional radiology procedures from 8 interventional radiology equipments of 6 university hospitals. The dose measurements were made by placing a thermoluminesent dosimeter(TLD) on various body surface of operation and assistant staff during actual interventional radiology. The measured points were the corner of the eyes, neck(on the thyroid) , wrists, chest(outside and inside of the protector), and back. Average radiation equivalent dose of the corner of left eye and left wrist of operating physicians were 1.19 mSv(0.11∼4.13 mSv)/100 minutes fluoroscopy and 4.32 mSv(0.16∼11.0 mSv)/100 minutes fluoroscopy respectively. Average exposure dose may vary depending on the type of procedure, personal skills and the quality of equipment. These results will be contributed to prepare the guide line in interventional radiology in Korea

  3. Marks in Latin-American radiology

    International Nuclear Information System (INIS)

    Souza Almeida, S. de.

    1987-01-01

    An historical retrospective of Latin-American radiology is shortly presented. Several radiologic societies as well as personalities, scientists and doctors are reported emphasizing their contribuition to radiologic Latin-American culture. (M.A.C.) [pt

  4. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    Science.gov (United States)

    Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

    2013-10-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

  5. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Palmer, Antony L; Bradley, David; Nisbet, Andrew; Lee, Chris; Ratcliffe, Ailsa J

    2013-01-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit. (paper)

  6. Rational use of diagnostic radiology

    International Nuclear Information System (INIS)

    Racoveanu, N.T.; Volodin, V.

    1992-01-01

    Radiologists in USA and UK have since early 1970 questioned the efficacy of various radiological investigations and produced substantial evidence that more rational approaches are necessary. WHO initiated, in 1977, a programme which has issued four technical reports giving practical recommendations on how to rationalise the use of radiological examinations. Three main directions are considered: (1) Abandonment of routine radiological examinations, as procedures with no clinical or epidemiologic significance and which represent a waste of resources and patient dose. (2) Patient selection for various radiological investigations based on clinical criteria (high, intermediate, low yield). Selected patients have an increased prevalence of the given disease and the predictive value of radiological investigation is much higher. (3) Use of diagnostic algorithms with higher cost/efficiency and risk/benefit ratios, improving the outcome of radiological examinations. (author)

  7. Emergency radiological monitoring and analysis: Federal Radiological Monitoring and Assessment Center

    International Nuclear Information System (INIS)

    Thome, D.J.

    1995-01-01

    The US Federal Radiological Emergency Response Plan (FRERP) provides the framework for integrating the various Federal agencies responding to a major radiological emergency. The FRERP authorizes the creation of the Federal Radiological Monitoring and Assessment Center (FRMAC), which is established to coordinate all Federal agencies involved in the monitoring and assessment of the off-site radiological conditions in support of the impacted State(s) and the Lead Federal Agency (LFA). Within the FRMAC, the Monitoring and Analysis Division (M ampersand A) is responsible for coordinating all FRMAC assets involved in conducting a comprehensive program of environmental monitoring, sampling, radioanalysis, and quality assurance. To assure consistency, completeness, and the quality of the data produced, a methodology and procedures manual is being developed. This paper discusses the structure, assets, and operations of the FRMAC M ampersand A and the content and preparation of the manual

  8. Implementation of a remote system for monitoring of radiological areas of radiological areas

    International Nuclear Information System (INIS)

    Velazquez E, Walter; Galuppo G, Emiliano; Gutierrez G, Jorge; Reyes R, Jerson

    2008-01-01

    Full text: Introduction: The present work shows the development of a radiation remote monitoring system which control radiological areas in the principal facilities at CCHEN and the development in the last years to use this system called SMARR (Remote Radiological Area Monitoring System). This is an important issue in radiological safety is to know 'on line' and in a 'continuously way' the radiological variables of areas, especially if in these areas people manage radioactive sources or material, the monitoring system are operative on La Reina and Lo Aguirre Nuclear Centers. This 'knowledge' gets a good support to the radiological safety to safeguard the environment and people in the facilities. Nuclear Chilean Commission: Actually, this system is daily operating to register the background radiation and level operation, for example of the facilities research reactor, cyclone, irradiators, in order to probe the behaviors under operational requirements. The system was made using common Geiger Muller and NaI detectors. This signal is received, data by data, for a collector computer which uses a Labview program to do this displayed on a screen computer using graphics to show the activity on a radiological area, and when the lectures pass a setting value automatically the system send by e-mail and text message which also can be received for cell phones enabled for this for the supervisor. Each monitored facility is completely independent of each other and store a data backup, also every installation are monitoring with server computer, it's concentrating the information and allow to view it on line in real time, trough the intranet and internet network. In addition, the information is stored in the special report in the server and available for to do a statistics and identify the operation periods, and control of radioactive sources. The Industry: The radiological protection on industry is necessary today, the typical instrumentation on the industry is growing up in the

  9. Ergonomics in radiology

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, N. [Department of Radiology, University Hospital of Wales, Cardiff (United Kingdom)], E-mail: nimitgoyal@doctors.org.uk; Jain, N.; Rachapalli, V. [Department of Radiology, University Hospital of Wales, Cardiff (United Kingdom)

    2009-02-15

    The use of computers is increasing in every field of medicine, especially radiology. Filmless radiology departments, speech recognition software, electronic request forms and teleradiology are some of the recent developments that have substantially increased the amount of time a radiologist spends in front of a computer monitor. Computers are also needed for searching literature on the internet, communicating via e-mails, and preparing for lectures and presentations. It is well known that regular computer users can suffer musculoskeletal injuries due to repetitive stress. The role of ergonomics in radiology is to ensure that working conditions are optimized in order to avoid injury and fatigue. Adequate workplace ergonomics can go a long way in increasing productivity, efficiency, and job satisfaction. We review the current literature pertaining to the role of ergonomics in modern-day radiology especially with the development of picture archiving and communication systems (PACS) workstations.

  10. Ergonomics in radiology

    International Nuclear Information System (INIS)

    Goyal, N.; Jain, N.; Rachapalli, V.

    2009-01-01

    The use of computers is increasing in every field of medicine, especially radiology. Filmless radiology departments, speech recognition software, electronic request forms and teleradiology are some of the recent developments that have substantially increased the amount of time a radiologist spends in front of a computer monitor. Computers are also needed for searching literature on the internet, communicating via e-mails, and preparing for lectures and presentations. It is well known that regular computer users can suffer musculoskeletal injuries due to repetitive stress. The role of ergonomics in radiology is to ensure that working conditions are optimized in order to avoid injury and fatigue. Adequate workplace ergonomics can go a long way in increasing productivity, efficiency, and job satisfaction. We review the current literature pertaining to the role of ergonomics in modern-day radiology especially with the development of picture archiving and communication systems (PACS) workstations

  11. How Secure Is Your Radiology Department? Mapping Digital Radiology Adoption and Security Worldwide.

    Science.gov (United States)

    Stites, Mark; Pianykh, Oleg S

    2016-04-01

    Despite the long history of digital radiology, one of its most critical aspects--information security--still remains extremely underdeveloped and poorly standardized. To study the current state of radiology security, we explored the worldwide security of medical image archives. Using the DICOM data-transmitting standard, we implemented a highly parallel application to scan the entire World Wide Web of networked computers and devices, locating open and unprotected radiology servers. We used only legal and radiology-compliant tools. Our security-probing application initiated a standard DICOM handshake to remote computer or device addresses, and then assessed their security posture on the basis of handshake replies. The scan discovered a total of 2774 unprotected radiology or DICOM servers worldwide. Of those, 719 were fully open to patient data communications. Geolocation was used to analyze and rank our findings according to country utilization. As a result, we built maps and world ranking of clinical security, suggesting that even the most radiology-advanced countries have hospitals with serious security gaps. Despite more than two decades of active development and implementation, our radiology data still remains insecure. The results provided should be applied to raise awareness and begin an earnest dialogue toward elimination of the problem. The application we designed and the novel scanning approach we developed can be used to identify security breaches and to eliminate them before they are compromised.

  12. Constraints in the use of repair half times and mathematical modelling for the clinical application of HDR and PDR treatment schedules as an alternative for LDR brachytherapy

    International Nuclear Information System (INIS)

    Pop, L.A.M.; Broek, J.F.C.M. van den; Visser, A.G.; Kogel, A.J. van der

    1996-01-01

    Using theoretical models based on radiobiological principles for the design of new treatment schedules for HDR and PDR brachytherapy, it is important to realise the impact of assumptions regarding the kinetics of repair. Extrapolations based on longer repair half times in a continuous LDR reference scheme may lead to the calculation of dangerously high doses for alternative HDR and PDR treatment schedules. We used the clinical experience obtained with conventional ERT and LDR brachytherapy in head and neck cancer as a clinical guideline to check the impact of the radiobiological parameters used. Biologically equivalent dose (BED) values for the in clinical practice of LDR brachytherapy recommended dose of 65-70 Gy (prescribed at a dose rate between 30-50 cGy/h) are calculated as a function of the repair half time. These BED values are compared with the biological effect of a clinical reference dose of conventional ERT with 2 Gy/day and complete repair between the fractions. From this comparison of LDR and ERT treatment schedules, a range of values for the repair half times of acute or late responding tissues is demarcated with a reasonable fit to the clinical data. For the acute effects (or tumor control) the best fits are obtained for repair half times of about 0.5 h, while for late effects the repair half times are at least 1 h and can be as high as 3 h. Within these ranges of repair half times for acute and late effects, the outcome of 'alternative' HDR or PDR treatment schedules are discussed. It is predominantly the late reacting normal tissue with the longer repair half time for which problems will be encountered and no or only marginal gain is to be expected of decreasing the dose rate per pulse in PDR brachytherapy

  13. Emergency radiological monitoring and analysis United States Federal Radiological Monitoring and Assessment Center

    International Nuclear Information System (INIS)

    Thome, D.J.

    1994-01-01

    The United States Federal Radiological Emergency Response Plan (FRERP) provides the framework for integrating the various Federal agencies responding to a major radiological emergency. Following a major radiological incident the FRERP authorizes the creation of the Federal Radiological Monitoring and Assessment Center (FRMAC). The FRMAC is established to coordinate all Federal agencies involved in the monitoring and assessment of the off-site radiological conditions in support of the impacted states and the Lead Federal Agency (LFA). Within the FRMAC, the Monitoring and Analysis Division is responsible for coordinating all FRMAC assets involved in conducting a comprehensive program of environmental monitoring, sampling, radioanalysis and quality assurance. This program includes: (1) Aerial Radiological Monitoring - Fixed Wing and Helicopter, (2) Field Monitoring and Sampling, (3) Radioanalysis - Mobile and Fixed Laboratories, (4) Radiation Detection Instrumentation - Calibration and Maintenance, (5) Environmental Dosimetry, and (6) An integrated program of Quality Assurance. To assure consistency, completeness and the quality of the data produced, a methodology and procedures handbook is being developed. This paper discusses the structure, assets and operations of FRMAC monitoring and analysis and the content and preparation of this handbook

  14. Informatics in radiology: radiology gamuts ontology: differential diagnosis for the Semantic Web.

    Science.gov (United States)

    Budovec, Joseph J; Lam, Cesar A; Kahn, Charles E

    2014-01-01

    The Semantic Web is an effort to add semantics, or "meaning," to empower automated searching and processing of Web-based information. The overarching goal of the Semantic Web is to enable users to more easily find, share, and combine information. Critical to this vision are knowledge models called ontologies, which define a set of concepts and formalize the relations between them. Ontologies have been developed to manage and exploit the large and rapidly growing volume of information in biomedical domains. In diagnostic radiology, lists of differential diagnoses of imaging observations, called gamuts, provide an important source of knowledge. The Radiology Gamuts Ontology (RGO) is a formal knowledge model of differential diagnoses in radiology that includes 1674 differential diagnoses, 19,017 terms, and 52,976 links between terms. Its knowledge is used to provide an interactive, freely available online reference of radiology gamuts ( www.gamuts.net ). A Web service allows its content to be discovered and consumed by other information systems. The RGO integrates radiologic knowledge with other biomedical ontologies as part of the Semantic Web. © RSNA, 2014.

  15. Photovoltaics for appliances and small systems. Enhancement of the PVS for Windows simulation program for development and simulation of PV appliances and small systems. Final report; Photovoltaik fuer Geraete und Kleinsysteme. Erweiterung des Simulationsprogramms PVS fuer Windows zur Entwicklung und Simulation von PV-versorgten Geraeten und Kleinsystemen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.; Imann, C.; Jung, V.

    2002-06-28

    The PVS simulation program for Windows was to be extended to the development and simulation of PV-supported equipment and small systems. The following new functions were to be integrated: a) Simulation and dimensioning of indoor power supply of systems with different light sources and independent outdoor systems. b)Integration of small wind generators in the simulation and dimensioning of isolated autonomous systems, including wind data and a component database for small wind turbines; c) Differentiation of the PVS battery model for different battery types (lead, Ni/Cd, Li etc.), optimized operating strategies and flexible dimensioning including an additional component database for battery types; d) Extensive cost analysis for PV-supported appliances and small systems, from investments to consumption, operation and maintenance. This will facilitate investment decisions and help systems of this type along in the market. All program components were designed for high flexibility. Users should be able to vary as many parameters as possible, and to generate and modify their own records. The current project focused on the user interface, i.e. input, data processing, and output. Parallel to this, the Fraunhofer ISE Institute worked on modifications of the computer hardware. [German] Das Projekt zielte auf eine Erweiterung des Simulationsprogramms PVS fuer Windows zur Entwicklung und Simulation von PV-versorgten Geraeten und Kleinsystemen hin. Das Entwicklungsprodukt sollte zusaetzlich zu den bisherigen Funktionen insbesondere Folgendes leisten: (a) Simulation und Dimensionierung der Energieversorgung von Geraeten im Indoor-Bereich, wobei unterschiedliche Lichtquellen verarbeitet werden muessen, sowie von sonstigen netzfreien (Outdoor-) Kleinsystemen. (b) Einbindung kleiner Windgeneratoren in die Simulation und Dimensionierung von netzfernen Systemen (Insel-Anlagen), einschliesslich Bereitstellung der Wind-Daten und einer zusaetzlichen Komponenten-Datenbank fuer kleine

  16. Mobile technology in radiology resident education.

    Science.gov (United States)

    Korbage, Aiham C; Bedi, Harprit S

    2012-06-01

    The authors hypothesized that ownership of a mobile electronic device would result in more time spent learning radiology. Current trends in radiology residents' studying habits, their use of electronic and printed radiology learning resources, and how much of the funds allotted to them are being used toward printed vs electronic education tools were assessed in this study. A survey study was conducted among radiology residents across the United States from June 13 to July 5, 2011. Program directors listed in the Association of Program Directors in Radiology e-mail list server received an e-mail asking for residents to participate in an online survey. The questionnaire consisted of 12 questions and assessed the type of institution, the levels of training of the respondents, and book funds allocated to residents. It also assessed the residents' study habits, access to portable devices, and use of printed and electronic radiology resources. Radiology residents are adopters of new technologies, with 74% owning smart phones and 37% owning tablet devices. Respondents spend nearly an equal amount of time learning radiology from printed textbooks as they do from electronic resources. Eighty-one percent of respondents believe that they would spend more time learning radiology if provided with tablet devices. There is considerable use of online and electronic resources and mobile devices among the current generation of radiology residents. Benefits, such as more study time, may be obtained by radiology programs that incorporate tablet devices into the education of their residents. Copyright © 2012 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  17. Comparison of the distribution of non-radiological and radiological fatal risk in Ontario industries (addendum)

    International Nuclear Information System (INIS)

    Davis, C.K.; Forbes, W.F.; Hayward, L.M.

    1986-09-01

    Occupational limits for exposure to ionizing radiation, in force in Canada, are based on recommendations of international bodies, particularly the International Commission on Radiological Protection (ICRP). To determine whether the ICRP assertions concerning the similarity of the distributions of occupational risk at the higher risk levels (from non-radiation and from radiation work) to Canada a study of the high end of the distributions of non-radiological risk of occupational fatalities in the province of Ontario was performed. For the present study total doses from exposure to sources of ionizing radiation for Ontario workers were converted to relative risk rates to allow direct comparison with the non-radiological results. In addition, absolute values for the radiological risk rates (RRR) were derived. The radiological risk estimates are based on workers who work both from nuclear reactions and from X-rays. The conclusion is made that the radiological and non-radiological risk rate (NRRR) distributions are similar in shape, but the RRR are approximately 1 to 27 percent of the NRRR, depending on the industry concerned

  18. High-dose-rate intracavitary brachytherapy (HDR-IC) in treatment of cervical carcinoma: 5-year results and implication of increased low-grade rectal complication on initiation of an HDR-IC fractionation scheme

    International Nuclear Information System (INIS)

    Wang Chongjong; Wan Leung, Stephen; Chen Huichun; Sun Limin; Fang Fumin; Changchien Chanchao; Huang Engyen; Wu Jiaming; Chen Chuhnchih

    1997-01-01

    Purpose: To report the treatment results and rectal/bladder complications of cervical carcinoma radically treated with high-dose-rate intracavitary brachytherapy (HDR-IC). The current policy of using three-fraction scheme was examined. Methods and Materials: Between November 1987 and August 1990, 173 patients with cervical carcinoma were treated with curative-intent radiation therapy. Whole pelvic irradiation was administered with 10-MV X ray. Dose to the central cervix was 40-44 Gy in 20-22 fractions, following by pelvic wall boost 6-14 Gy in three to seven fractions with central shielding. 60 Co sources were used for HDR-IC, and 7.2 Gy was given to Point A for three applications, 1-2 weeks apart. Duration of follow-up was 5-7.8 years. Results: Twenty-eight patients (16%) developed central-regional recurrences. Overall 5-year actuarial pelvic control rate was 83%. By stage, 5-year actuarial pelvic control rates were 94%, 87%, and 72% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Thirty-one patients (18%) developed distant metastasis. Overall 5-year actuarial survival rate was 58%. By stage, 5-year actuarial survival rates were 79%, 59%, and 41% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Sixty-six (38%) and 19 patients (11%) developed rectal and bladder complications, respectively. For rectal complication, the overall actuarial rate was 38% at 5 years. By grade, 5-year actuarial rectal complication rates were 24%, 15%, 4%, and 3% for Grades 1-4, respectively. Overall prevalence of rectal complications was 37% and 14% at 2 and 5 years, respectively. Prevalence of low-grade rectal complication (Grades 1 and 2) was dominant at 2 years (30%), but declined to 8% at 5 years. Prevalence of high-grade, severe rectal complication (Grades 3 and 4) remained steady at 2 and 5 years (7% and 6%, respectively). Five-year actuarial bladder complication was 9%. Five-year prevalence of bladder complication was 2%. Conclusion: Using a three

  19. Radiological assessment and optimization

    International Nuclear Information System (INIS)

    Zeevaert, T.; Sohier, A.

    1998-01-01

    The objectives of SCK-CEN's research in the field of radiological assessment and optimization are (1) to implement ALARA principles in activities with radiological consequences; (2) to develop methodologies for radiological optimization in decision-aiding; (3) to improve methods to assess in real time the radiological hazards in the environment in case of an accident; (4) to develop methods and programmes to assist decision-makers during a nuclear emergency; (5) to support the policy of radioactive waste management authorities in the field of radiation protection; (6) to investigate computer codes in the area of multi criteria analysis; (7) to organise courses on off-site emergency response to nuclear accidents. Main achievements in these areas for 1997 are summarised

  20. Radiology. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Reiser, Maximilian; Kuhn, Fritz-Peter; Debus, Juergen

    2011-01-01

    The text book on radiology covers the following issues: Part A: General radiology: Fundamental physics: radiation biology; radiation protection fundamentals: radiologic methods; radiotherapy; nuclear medicine. Part B: Special radiology: Thorax; heart; urogenital tract and retroperitoneum; vascular system and interventional radiology; esophagus, stomach, small and large intestines; liver, biliary system, pancreas and spleen; mammary glands; central nervous system; spinal cord and spinal canal; basis of the skull, facial bones and eye socket; neck; pediatric imaging diagnostics.

  1. Radiological Worker Training: Radiological Worker 1 lesson plans

    International Nuclear Information System (INIS)

    1992-10-01

    Upon completion of this training course, the participant will have the knowledge to work safely in areas controlled for radiological purposes using proper radiological practices. Upon completion of this unit the participant will be able to identify the fundamentals of radiation, radioactive material and radioactive contamination. The participant will be able to select the correct response from a group of responses which verifies his/her ability to: Define ionizing radiation, radioactive material and radioactive contamination and identify the units used to measure radiation and radioactivity

  2. Federal support of radiological research

    International Nuclear Information System (INIS)

    Hendee, W.R.

    1981-01-01

    Pervading the plans and objective outlined herein for continued and enhanced federal support of research in radiology is a challenge of unparalleled magnitude, for the economic foundation on which this support is based has rarely been more precarious. The new administration in Washington may well be the most fiscally constrained in half a century, and its stated interest in reducing federal expenditures could have disastrous consequences for the scientific research effort in this country, including that in radiology and the radiological sciences. The circumvention of these consequences may well require the dedicated effort of the entire scientific community over the next few months and years, including that part representing radiology and the radiological sciences

  3. 21 CFR 892.1980 - Radiologic table.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiologic table. 892.1980 Section 892.1980 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1980 Radiologic table. (a) Identification. A radiologic...

  4. Clinical evaluation of a medical high dynamic range display

    International Nuclear Information System (INIS)

    Marchessoux, Cedric; Paepe, Lode de; Vanovermeire, Olivier; Albani, Luigi

    2016-01-01

    function of the local average luminance around the nodules. For the lowest luminance range, there is more than 30% in favor of the HDR display. For the highest luminance range, there is less than 6% in favor of the LDR display. Conclusions: This study shows the potential benefit of using a HDR display in radiology.

  5. RADRELAY RADIOLOGICAL DATA LINK DEVICE

    International Nuclear Information System (INIS)

    Harpring, L.; Frank Heckendorn, F.

    2007-01-01

    The RadRelay effort developed small, field appropriate, portable prototype devices that allow radiological spectra to be downloaded from field radiological detectors, like the identiFINDER-U, and transmitted to land based experts. This communications capability was designed for the U. S. Coast Guard (USCG) but is also applicable to the Customs and Border Protection (CBP) personnel working in remote locations. USCG Level II personnel currently use the identiFINDER-U Hand-Held Radioisotope ID Devices (HHRIID) to detect radiological materials during specific boarding operations. These devices will detect not only radiological emissions but will also evaluate those emissions against a table of known radiological spectra. The RadRelay has been developed to significantly improve the functionality of HHRIID, by providing the capability to download radiological spectra and then transmit them using satellite or cell phone technology. This remote wireless data transfer reduces the current lengthy delay often encountered between the shipboard detection of unknown radiological material and the evaluation of that data by technical and command personnel. That delay is reduced from hours to minutes and allows the field located personnel to remain on station during the inspection and evaluation process

  6. SU-E-T-242: Design of a Novel Afterloader Clearance QA Device for Biliary HDR Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, JP; Deufel, CL [Mayo Clinic, Rochester, MN (United States)

    2015-06-15

    Purpose: Bile duct cancer affects 2–3 thousand people annually in the United States. Radiation therapy has been shown to double median survival, with combined external beam and intraluminal high dose-rate (HDR) brachytherapy being most effective. Endoscopic retrograde cholangiopancreatography (ERCP) biliary HDR, a less-invasive alternative to trans-hepatic brachytherapy, is delivered through a catheter that travels a tortuous path from nose to bile duct, requiring wire drive force and dexterity beyond typical afterloader performance specifications. Thus, specific afterloader quality assurance(QA) is recommended for this procedure. Our aim was to create a device and process for Varisource afterloader clearance QA with objectives that it be quantitative and can monitor afterloader performance over time, compare performance between two distinct afterloaders and potentially Result in a predictive nomogram for patient-specific clearance. Methods: Based on retrospective reconstruction of 20 ERCP patient anatomies, we designed a phantom to test afterloader ability to drive the source wire along an intended treatment path. The ability of the afterloader to fully extend the intended treatment path is a function of number and diameters of turns. We have determined experimentally that relative position of the turns does not impact performance. Results: Both patient and QA paths involve three common turns/loops: a large turn representing the stomach(10.8cm±2.0cm), an elliptical loop representing the duodenum(7.3cm±1.5cmx4.8cm±0.7cm), and a final turn at the end of the bile duct that may be tight for some patient-specific anatomies and absent in others(3.7cm±0.7cm, where present). Our phantom design uses anatomical average turn diameters for the stomach and duodenum then terminates in a turn of quantitatively selectable diameter. The smallest final turn diameter that an afterloader can pass is recorded as the QA parameter. Conclusion: With this device and QA process, we

  7. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Département de physique, de génie physique et d’optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de radio-oncologie et Axe Oncologie du Centre de recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Binnekamp, Dirk [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best 5680 DA (Netherlands)

    2015-03-15

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  8. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    International Nuclear Information System (INIS)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc; Binnekamp, Dirk

    2015-01-01

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora ® Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators

  9. Radiological hazards

    International Nuclear Information System (INIS)

    Hamilton, M.

    1984-01-01

    The work of the (United Kingdom) National Radiological Protection Board is discussed. The following topics are mentioned: relative contributions to genetically significant doses of radiation from various sources; radon gas in non-coal mines and in dwelling houses; effects of radiation accidents; radioactive waste disposal; radiological protection of the patient in medicine; microwaves, infrared radiation and cataracts; guidance notes for use with forthcoming Ionising Radiations Regulations; training courses; personal dosimetry service; work related to European Communities. (U.K.)

  10. Health surveillance of radiological work

    International Nuclear Information System (INIS)

    Pauw, H.; Vliet, J.V.D.; Zuidema, H.

    1988-01-01

    Shielding x-ray devices and issuing film badges to radiological workers in 1936 can be considered the start of radiological protection in the Philips enterprises in the Netherlands. Shielding and equipment were constantly improved based upon the dosimetry results of the filmbadges. The problem of radioactive waste led to the foundation of a central Philips committee for radiological protection in 1956, which in 1960 also issued an internal license system in order to regulate the proper precautions to be taken : workplace design and layout, technological provisions and working procedures. An evaluation of all radiological work in 1971 learnt that a stricter health surveillance program was needed to follow up the precautions issued by the license. On one hand a health surveillance program was established and on the other hand all types of radiological work were classified. In this way an obligatory and optimal health surveillance program was issued for each type of radiological work

  11. SU-F-T-29: The Important of Each Fraction Image-Guided Planning for Postoperative HDR-Brachytherapy in Endometrial Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Piriyasang, D; Pattaranutaporn, P; Manokhoon, K [Ramathibodi Hospital, Rachatewi, Bangkok (Thailand)

    2016-06-15

    Purpose: Cylindrical applicators are often used for postoperative HDRbrachytherapy in endometrial carcinoma. It has been considered that dosimetric variation between fractions for this treatment is minimal and might not be necessary to perform treatment planning for every fractions. At our institute, it is traditional to perform treatment planning with CT simulation on the first fraction and uses this plan for the rest of treatment. This study was aim to evaluate the errors of critical structure doses between the fractions when simulation and planning were done for first fraction only. Methods: Treatment plans of 10 endometrial carcinoma patients who received postoperative HDR-brachytherapy and underwent CT-simulation for every HDR-fractions at our department were retrospectively reviewed. All of these patients were treated with cylindrical applicator and prescribed dose 15Gy in 3 fractions to 0.5cm from vaginal surface. The treatment plan from the first fraction was used to simulate in second and third CT-simulation. Radiation dose for critical structures in term of Dose-to-2cc (D2cc) were evaluated and compared between planning CT. Results: The D2cc for bladder and rectum were evaluated. For bladder, the mean error of D2cc estimation for second and third fractions was 7.6% (0.1–20.1%, SD=5.7). And the mean error for D2cc of rectum was 8.5% (0.1–29.4%, SD=8.5). Conclusion: The critical structure doses could be significant difference between fractions which may affects treatment outcomes or toxicities. From our data, image-guided brachytherapy at least with CT-Simulation should be done for every treatment fractions.

  12. SU-G-TeP2-07: Dosimetric Characterization of a New HDR Multi-Channel Esophageal Applicator for Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, A; Gao, S; Greskovich, J; Wilkinson, D [Cleveland Clinic, Cleveland, OH (United States); Diener, T [Cleveland State University, Cleveland, OH (United States)

    2016-06-15

    Purpose: To characterize the dose distribution of a new multi-channel esophageal applicator for brachytherapy HDR treatment, and particularly the effect of the presence of air or water in the applicator’s expansion balloon. Methods: A new multi-channel (6) inflatable applicator for esophageal HDR has been developed in house and tested in a simple water phantom. CT image sets were obtained under several balloon expansions (80ml of air, 50 cc of water), and channel loadings and used with the Oncentra (Elekta) planning system based on TG43 formalism. 400 cGy was prescribed to a plane 1cm away from the applicator. Planar dose distributions were measured for that plane and one next to the applicator using Gafchromic EBT3 film and scanned by a Vidar VXR-12 film digitizer. Film and TPS generated dose distributions of film were sent to OmniPro I’mRT (iba DOSIMETRY) for analysis. 2D dose profiles in both X and Y directions were compared and gamma analysis performed. Results: Film dose measurement of the air-inflated applicator is lower than the TPS calculated dose by as much as 60%. Only 80.8% of the pixels passed the gamma criteria (3%/3mm). For the water-inflated applicator, the measured film dose is fairly close to the TPS calculated dose (typically within <3%). 99.84% of the pixels passed the gamma criteria (3%/3mm). Conclusion: TG43 based calculations worked well when water was used in the expansion balloon. However, when air is present in that balloon, the neglect of heterogeneity corrections in the TG43 calculation results in large differences between calculated and measured doses. This could result in severe underdosing when used in a patient. This study illustrates the need for a TPS with an advanced algorithm which can account for heterogeneity. Supported by Innovations Department, Cleveland Clinic.

  13. SU-F-T-24: Impact of Source Position and Dose Distribution Due to Curvature of HDR Transfer Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A; Yue, N [Rutgers University, New Brunswick, NJ (United States)

    2016-06-15

    Purpose: Brachytherapy is a highly targeted from of radiotherapy. While this may lead to ideal dose distributions on the treatment planning system, a small error in source location can lead to change in the dose distribution. The purpose of this study is to quantify the impact on source position error due to curvature of the transfer tubes and the impact this may have on the dose distribution. Methods: Since the source travels along the midline of the tube, an estimate of the positioning error for various angles of curvature was determined using geometric properties of the tube. Based on the range of values a specific shift was chosen to alter the treatment plans for a number of cervical cancer patients who had undergone HDR brachytherapy boost using tandem and ovoids. Impact of dose to target and organs at risk were determined and checked against guidelines outlined by radiation oncologist. Results: The estimate of the positioning error was 2mm short of the expected position (the curved tube can only cause the source to not reach as far as with a flat tube). Quantitative impact on the dose distribution is still in the process of being analyzed. Conclusion: The accepted positioning tolerance for the source position of a HDR brachytherapy unit is plus or minus 1mm. If there is an additional 2mm discrepancy due to tube curvature, this can result in a source being 1mm to 3mm short of the expected location. While we do always attempt to keep the tubes straight, in some cases such as with tandem and ovoids, the tandem connector does not extend as far out from the patient so the ovoid tubes always contain some degree of curvature. The dose impact of this may be significant.

  14. An overview of dental radiology: a primer on dental radiology

    International Nuclear Information System (INIS)

    Manny, E.F.; Carlson, K.C.; McClean, P.M.; Rachlin, J.A.; Segal, P.

    1980-01-01

    To provide medical and scientific background on certain selected technologies generally considered to be of particular significance, the National Center for Health Care Technology (NCHCT) has commissioned a series of overview papers. This is one of several projects entered into jointly by the Bureau of Radiological Health (BRH) and NCHCT relating to the use of radiation for health care. Dental radiation protection has been a long-time interest of BRH. Both past and on-going efforts to minimize population radiation exposure from electronic products have included specific action programs directed at minimizing unnecessary radiation exposure to the population from dental radiology. Current efforts in quality assurance and referral criteria are two aspects of NCHCT's own assessment of this technology which are described within the larger picture presented in this overview. The issues considered in this document go beyond the radiation exposure aspects of dental x-ray procedures. To be responsive to the informational needs of NCHCT, the assessment includes various other factors that influence the practice of dental radiology. It is hoped this analysis will serve as the basis for planning and conducting future programs to improve the practice of dental radiology

  15. Radiology's value chain.

    Science.gov (United States)

    Enzmann, Dieter R

    2012-04-01

    A diagnostic radiology value chain is constructed to define its main components, all of which are vulnerable to change, because digitization has caused disaggregation of the chain. Some components afford opportunities to improve productivity, some add value, while some face outsourcing to lower labor cost and to information technology substitutes, raising commoditization risks. Digital image information, because it can be competitive at smaller economies of scale, allows faster, differential rates of technological innovation of components, initiating a centralization-to-decentralization technology trend. Digitization, having triggered disaggregation of radiology's professional service model, may soon usher in an information business model. This means moving from a mind-set of "reading images" to an orientation of creating and organizing information for greater accuracy, faster speed, and lower cost in medical decision making. Information businesses view value chain investments differently than do small professional services. In the former model, producing a better business product will extend image interpretation beyond a radiologist's personal fund of knowledge to encompass expanding external imaging databases. A follow-on expansion with integration of image and molecular information into a report will offer new value in medical decision making. Improved interpretation plus new integration will enrich and diversify radiology's key service products, the report and consultation. A more robust, information-rich report derived from a "systems" and "computational" radiology approach will be facilitated by a transition from a professional service to an information business. Under health care reform, radiology will transition its emphasis from volume to greater value. Radiology's future brightens with the adoption of a philosophy of offering information rather than "reads" for decision making. Staunchly defending the status quo via turf wars is unlikely to constitute a

  16. Gout. Radiological aspects

    International Nuclear Information System (INIS)

    Restrepo Suarez, Jose Felix; Pena Cortes, Mario; Rondon Herrera, Federico; Iglesias Gamarra, Antonio; Calvo Paramo, Enrique

    2000-01-01

    In this paper we reviewed the clinical and radiological aspects of gout, showing the most frequent radiological findings that can guide to the correct diagnosis of the disease. The cases that we presented here have been analyzed for many years in our rheumatology service, Universidad Nacional de Colombia, Hospital San Juan de Dios, Bogota

  17. Commissioning and quality assurance procedures for the HDR Valencia skin applicators

    Directory of Open Access Journals (Sweden)

    Domingo Granero

    2016-11-01

    Full Text Available The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR 192 Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm. The user must perform commissioning and periodic testing of these applicators to guarantee the proper and safe delivery of the intended absorbed dose, as recommended in the standards in radiation oncology. In this study, based on AAPM and GEC-ESTRO guidelines for brachytherapy units and our experience, a set of tests for the commissioning and periodic testing of the Valencia applicators is proposed. These include general considerations, verification of the manufacturer documentation and physical integrity, evaluation of the source-to-indexer distance and reproducibility, setting the library plan in the treatment planning system, evaluation of flatness and symmetry, absolute output and percentage depth dose verification, independent calculation of the treatment time, and visual inspection of the applicator before each treatment. For each test, the proposed methodology, equipment, frequency, expected results, and tolerance levels (when applicable are provided.

  18. Diagnostic and interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J. [Klinikum der Johann Wolfgang Goethe-Universitaet, Frankfurt am Main (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Reith, Wolfgang [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie; Rummeny, Ernst J. (ed.) [Technische Univ. Muenchen Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Radiologie

    2016-08-01

    This exceptional book covers all aspects of diagnostic and interventional radiology within one volume, at a level appropriate for the specialist. From the basics through diagnosis to intervention: the reader will find a complete overview of all areas of radiology. The clear, uniform structure, with chapters organized according to organ system, facilitates the rapid retrieval of information. Features include: Presentation of the normal radiological anatomy Classification of the different imaging procedures according to their diagnostic relevance Imaging diagnosis with many reference images Precise description of the interventional options The inclusion of many instructive aids will be of particular value to novices in decision making: Important take home messages and summaries of key radiological findings smooth the path through the jungle of facts Numerous tables on differential diagnosis and typical findings in the most common diseases offer a rapid overview and orientation Diagnostic flow charts outline the sequence of diagnostic evaluation All standard procedures within the field of interventional radiology are presented in a clinically relevant and readily understandable way, with an abundance of illustrations. This is a textbook, atlas, and reference in one: with more than 2500 images for comparison with the reader's own findings. This comprehensive and totally up-to-date book provides a superb overview of everything that the radiology specialist of today needs to know.

  19. Medical radiology terminology

    International Nuclear Information System (INIS)

    1986-01-01

    Standardization achievements in the field of radiology induced the IEC to compile the terminology used in its safety and application standards and present it in publication 788 (1984 issue), entitled 'Medical radiology terminology'. The objective pursued is to foster the use of standard terminology in the radiology standards. The value of publication 788 lies in the fact that it presents definitions of terms used in the French and English versions of IEC standards in the field of radiology, and thus facilitates adequate translation of these terms into other languages. In the glossary in hand, German-language definitions have been adopted from the DIN standards in cases where the French or English versions of definitions are identical with the German wording or meaning. The numbers of DIN standards or sections are then given without brackets, ahead of the text of the definition. In cases where correspondance of the various texts is not so good, or reference should be made to a term in a DIN standard, the numbers are given in brackets. (orig./HP) [de

  20. The radiological technologist

    International Nuclear Information System (INIS)

    Bundy, A.L.

    1988-01-01

    Radiologists rely upon the talents of the technologists with whom they work. Indeed, a good technologist will only enhance the radiologist's performance. Radiological technologists no longer solely take radiographs, but are involved in many more detailed areas of imaging, such as computered tomography, magnetic resonance imaging, nuclear radiology, ultrasound, angiography, and special procedures. They are also required to make decisions that affect the radiological examination. Besides the degree in radiological technology (RT), advanced degrees in nuclear medicine technology (NMT) and diagnostic medical sonography (RDMS) are attainable. The liability of the technologist is not the same as the radiologist involved, but the liability is potentially real and governed by a subdivision of jurisprudence known as agency law. Since plaintiffs and attorneys are constantly searching for new frontiers of medical liability, it is wise for the radiologist and technologist to be aware of the legalities governing their working relationship and to behave accordingly. The legal principles that apply to this working relationship are discussed in this chapter, followed by a presentation of some relevant and interesting cases that have been litigated

  1. Occupational radiological protection in diagnostic radiology

    International Nuclear Information System (INIS)

    Mota, H.C.

    1983-01-01

    The following topics are discussed: occupational expossure (the ALARA principle, dose-equivalent limit, ICRP justification); radiological protection planning (general aspects, barrier estimation) and determination of the occupational expossures (individual monitoring). (M.A.) [pt

  2. Radiological Control Manual. Revision 0, January 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records.

  3. Integrative teaching in Radiology. A survey

    International Nuclear Information System (INIS)

    Dettmer, S.; Weidemann, J.; Wacker, F.; Fischer, V.

    2015-01-01

    To survey integrative teaching in radiology at German universities. A questionnaire about radiological education was sent electronically to all 37 chairpersons of university radiology departments in Germany. The questions included the course type, teaching methods, concept, perception, and advantages and disadvantages of integrative teaching. Statistical analysis was performed with nonparametric statistics and chi-square test. The survey was considered representative with a return rate of 68%. Integrative teaching is established at 4/5 of all departments. Integrative teaching is well accepted with an acceptance rate that is significantly higher in so-called 'Modellstudiengaengen' (model courses of study) (100%) compared to conventional courses of study (72%). The advantages of integrative teaching include linking of content (92%) and preparation for interdisciplinary work (76%). The disadvantages include high effort (75%) and time (67%) for organization. Furthermore, there is a risk that basic radiological facts and knowledge cannot be conveyed and that the visibility of radiology as an independent discipline is lost. Conventional radiological teaching has a similarly high acceptance (84%) compared to integrative courses (76%). Integrative teaching has a high acceptance among chairpersons in radiology in Germany despite the greater effort. A good interdisciplinary collaboration is essential for integrative teaching and at the same time this can be conveyed to the students. However, the visibility of radiology as a discipline and the possibility to cover basic radiological content must be ensured. Therefore, both conventional courses and integrative teaching seems reasonable, especially in cross-disciplinary subjects such as radiology.

  4. Braquiterapia endoluminal HDR no tratamento de tumores primários ou recidivas na árvore traqueobrônquica Endoluminal high dose rate brachytherapy in the treatment of primary and recurrent bronchogenic tree malignancies

    Directory of Open Access Journals (Sweden)

    Maria Fortunato

    2009-03-01

    Full Text Available Introdução: Tumores localmente avançados como forma de apresentação inicial dos tumores localizados na árvore traqueobrônquica não são um fenómeno raro. A recidiva brônquica é um acontecimento frequente na história natural de algumas neoplasias. As opções terapêuticas são múltiplas, sendo no entanto dependentes de variáveis, como a terapêutica inicial utilizada, o local da recorrência, a sintomatologia e as condições físicas do doente. Objectivos: Demonstrar as principais vantagens terapêuticas da braquiterapia endoluminal (BTE com alta taxa de dose (HDR em tumores primários e na recidiva tumoral localizada na árvore traqueobrônquica. Material e métodos: Avaliámos retrospectivamente sete doentes (dts com tumor primário do cólon, traqueia e pulmão. A recidiva traqueobrônquica (dois dts na traqueia e cinco dts no brônquio ocorreu entre Março de 2003 e Setembro de 2004, os dts foram submetidos a BT HDR como terapêutica primária ou na recidiva, em associação com RTE, laserterapia e quimioterapia (QT, com intuito paliativo/ curativo. Na BTE HDR foram utilizadas doses de 5 a 7 Gy em duas a quatro fracções, prescritas a 1 cm do eixo da fonte. O tratamento consistiu na aplicação endoluminal de Ir192, utilizando um cateter 6 French. Resultados: Verificámos o rápido alívio sintomático associado à redução da massa tumoral em seis dos sete doentes submetidos a esta técnica. Em um dos seis doentes estudados observou-se uma progressão da doença local entre a 2.ª e a 3.ª fracções de tratamento (obstrução da traqueia. Com um follow-up mediano entre a terapêutica com BT e a avaliação do presente estudo de 17 meses (2 -40, três doentes estão vivos, um sem evidência de doença e dois apresentam uma recidiva brônquica; quatro faleceram, um após hemoptise maciça e três por progressão da doença. Discussão e conclusões Os dts submetidos a BT após recidiva tumoral endobrônquica ou com tumores

  5. A summary of the Fire Testing Program at the German HDR Test Facility

    International Nuclear Information System (INIS)

    Nowlen, S.P.

    1995-11-01

    This report provides an overview of the fire safety experiments performed under the sponsorship of the German government in the containment building of the decommissioned pilot nuclear power plant known as HDR. This structure is a highly complex, multi-compartment, multi-level building which has been used as the test bed for a wide range of nuclear power plant operation safety experiments. These experiments have included numerous fire tests. Test fire fuel sources have included gas burners, wood cribs, oil pools, nozzle release oil fires, and cable in cable trays. A wide range of ventilation conditions including full natural ventilation, full forced ventilation, and combined natural and forced ventilation have been evaluated. During most of the tests, the fire products mixed freely with the full containment volume. Macro-scale building circulation patterns which were very sensitive to such factors as ventilation configuration were observed and characterized. Testing also included the evaluation of selective area pressurization schemes as a means of smoke control for emergency access and evacuation stairwells

  6. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, E.; Sosa, M. A.; Gil V, A. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Av. Insurgentes 2354, 37150 Leon, Guanajuato (Mexico); Monzon, E., E-mail: eric_1985@fisica.ugto.mx [IMSS, Unidad Medica de Alta Especialidad No. 1, Av. Adolfo Lopez Mateos 1813, 37340 Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  7. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    International Nuclear Information System (INIS)

    Reyes, E.; Sosa, M. A.; Gil V, A.; Monzon, E.

    2015-10-01

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  8. Quality control in dental diagnostic radiology : anomalous in the use of radiological equipment

    International Nuclear Information System (INIS)

    Alcaraz, M.; Martinez-Beneyto, Y.; Jodar, S.; Velasco, E.; Garcia-Vera, M. C.

    2004-01-01

    7,176 official quality control reports on dental diagnostic radiology were studied, relating to dental clinics located in 37 Spanish provinces covering 16 different autonomous Regions. The reports were issued as a result of the entry into force of Royal Decree 2071/1995 on quality control in General Diagnostic Radiology facilities, this Royal Decree was replaced by R. D. 1976/1999. The reports were writen by the UTPR (Technical Unit of Radiological Protection) Agsigma S. A. L., a company approved by the Nuclear Safety Council, and they correspond with the official reports issued during 1996-2001. This meants that a 5-year period has been monitored in order to observe the impacts of the establlishment of this legislation on quality control in intraoral dental diagnostic radiology facilities. The results show that 72.79% of the reports checked in 2001 would comply with the European Union's official recommendation (70 kVp, 8 mA> 1.5 mm of Al and 20 cm collimator length). Significant alterations have detected in a third (30.59%) of the radiological equipment. (Author) 36 refs

  9. Continuing training in radiological protection as an effective means of avoiding radiological accidents

    International Nuclear Information System (INIS)

    Lima, C.M.A.; Pelegrineli, S.Q.; Martins, G.; Lima, A.R.; Silva, F.C.A. da

    2017-01-01

    it is notorious that one of the main causes of radiological accidents is the lack of knowledge of radiological protection of workers. In order to meet the needs of professionals in acquiring a solid base in radiological protection and safety, was created in 2013, by the Casa Branca School / SP and technically supported by the company MAXIM Cursos, the 'Post-Graduation Course Lato Sensu de Radiological Protection in Medical, Industrial and Nuclear Applications', which offers a broad improvement in radiation protection. The course of 380 hours and duration of 18 months is divided into 13 modules, including theoretical classes, in person and online using the virtual classroom and practical training in radiation protection in general. In the end students should present a monograph, guided by a course teacher and reviewed by an Examining Bank. Five classes have been formed in these four years, totaling 92 students. In all, 51 monographs have been defended on topics of technical and scientific interest. For this, the Faculty consists of 25 professors, being 9 Doctors, 13 Masters and 3 Specialists in Radiological Protection

  10. Laenderyggens degeneration og radiologi

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Gosvig, Kasper Kjaerulf; Sonne-Holm, Stig

    2006-01-01

    Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP and signi......Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP...... and significant relationships between radiological findings and subjective symptoms have both been notoriously difficult to identify. The lack of consensus on clinical criteria and radiological definitions has hampered the undertaking of properly executed epidemiological studies. The natural history of LBP...

  11. Recent trend of diagnostic radiology

    International Nuclear Information System (INIS)

    Kim, S.Y.; Kim, H.K.

    1979-01-01

    Present status and recent trend of diagnostic radiology have been reviewed. The interrelationships and Characteristics of various fields of radiology such as computed tomography, X-ray radiology, and nuclear medicine were discussed. The mevit of computed tomography and the promising use of short lived, accelerator produced radionuclides, and radiotherapy in nuclear medicine were emphasized. (author)

  12. The IPEM code of practice for determination of the reference air kerma rate for HDR 192Ir brachytherapy sources based on the NPL air kerma standard

    International Nuclear Information System (INIS)

    Bidmead, A M; Sander, T; Nutbrown, R F; Locks, S M; Lee, C D; Aird, E G A; Flynn, A

    2010-01-01

    This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR 192 Ir brachytherapy sources. In 2004, the National Physical Laboratory (NPL) commissioned a primary standard for the realization of RAKR of HDR 192 Ir brachytherapy sources. This has meant that it is now possible to calibrate ionization chambers directly traceable to an air kerma standard using an 192 Ir source (Sander and Nutbrown 2006 NPL Report DQL-RD 004 (Teddington: NPL) http://publications.npl.co.uk). In order to use the source specification in terms of either RAKR, .K R (ICRU 1985 ICRU Report No 38 (Washington, DC: ICRU); ICRU 1997 ICRU Report No 58 (Bethesda, MD: ICRU)), or air kerma strength, S K (Nath et al 1995 Med. Phys. 22 209-34), it has been necessary to develop algorithms that can calculate the dose at any point around brachytherapy sources within the patient tissues. The AAPM TG-43 protocol (Nath et al 1995 Med. Phys. 22 209-34) and the 2004 update TG-43U1 (Rivard et al 2004 Med. Phys. 31 633-74) have been developed more fully than any other protocol and are widely used in commercial treatment planning systems. Since the TG-43 formalism uses the quantity air kerma strength, whereas this COP uses RAKR, a unit conversion from RAKR to air kerma strength was included in the appendix to this COP. It is recommended that the measured RAKR determined with a calibrated well chamber traceable to the NPL 192 Ir primary standard is used in the treatment planning system. The measurement uncertainty in the source calibration based on the system described in this COP has been reduced considerably compared to other methods based on interpolation techniques.

  13. Role of radiology in occupational medicine

    International Nuclear Information System (INIS)

    Vehmas, T.

    2004-01-01

    This review discusses the contribution of radiology to occupational medicine as well as work-related problems in radiology dept.s. Research issues are emphasized. Radiology has been used especially when diagnosing occupational respiratory and locomotive system problems and solvent-induced encephalo- and hepatopathy. The aim of research in these areas is usually to characterize occupational diseases and to identify physico-chemical hazards in the work place by comparing between groups of workers and non-exposed controls. Radiological imaging allows an objective characterization of the disease, and it may clarify the pathogenesis of the process and provide a useful epidemiological tool. Advanced statistical methods are often needed to adjust analyses for confounding variables. As the diagnostic requirements are increasing, more sensitive and sophisticated radiological methods, such as high-resolution computed tomography, magnetic resonance imaging and magnetic resonance spectroscopy, may be required for the early recognition of occupational health risks. This necessitates good cooperation between occupational health units and well-equipped imaging dept.s. Considering occupational problems in radiology departments, the increasing use of digital radiology requires ergonomic measures to control and prevent locomotive problems caused by work with computers. Radiation protection measures are still worth concern, especially in interventional radiology

  14. Military radiology during the first world conflict

    International Nuclear Information System (INIS)

    Le Vot, J.

    2016-01-01

    Published at the occasion of the centenary of the First World War, this article proposes an historical overview of the emergence and development of military medical radiology during this conflict. The author first describes the situation of radiology in the different armies and countries on the eve of the war as this application of radiology is relatively recent (it is based on Roentgen's discovery in 1895). He indicates the first steps of emergence of radiology department in military hospitals, the interest of military physicians in radiology and the availability of mobile equipment which had been actually presented at the parade on the 14 July 1914. The author then highlights some important personalities who have been important actors of the development, application and use of radiology and of military radiology during the war. He proposes an overview of radiological equipment in 1914, of the variety of vehicles adapted to transport and use such equipment. He also comments how radiology professionals were trained

  15. SW England seismic monitoring for the HDR geothermal programme in Cornwall 1989 to September 1991

    International Nuclear Information System (INIS)

    Walker, A.B.

    1992-01-01

    The potential for earthquakes to be triggered by fluid injected into boreholes has been recognised for 25 years and natural earthquakes in Cornwall have been reported for over 250 years. As a result, the Geothermal Steering Committee advising the Hot Dry Rock project recommended that background seismic monitoring be undertaken around the HDR experimental site at Rosemanowes. A network of seismographs was established for this purpose by the British Geological Survey (BGS) in late 1980 and has been operated continuously through September 1991. The primary aim of the network has been to provide an independent, continuous assessment of all vibrational transients in order to discriminate between those caused by the Hot Dry Rock experiments and those of natural origin or from other man-made sources. In this respect, the work provides an insurance against claims that extraneous seismic activity is related to those experiments. (author)

  16. Evidence-based radiology: a new approach to evaluate the clinical practice of radiology

    International Nuclear Information System (INIS)

    Puig, S.; Felder-Puig, R.

    2006-01-01

    Over the last several years, the concept and methodology of evidence-based medicine (EBM) have received significant attention in the scientific community. However, compared to therapeutic medical disciplines, EBM-based radiological publications are still underrepresented. This article summarizes the principles of EBM and discusses the possibilities of their application in radiology. The presented topics include the critical appraisal of studies on the basis on EBM principles, the explanation of EBM-relevant statistical outcome parameters (e.g., ''likelihood ratio'' for diagnostic and ''number needed to treat'' for interventional procedures), as well as the problems facing evidence-based radiology. Evidence-based evaluation of radiological procedures does not only address aspects of cost-effectiveness, but is also particularly helpful in identifying patient-specific usefulness. Therefore it should become an integral part of radiologist training. (orig.)

  17. Integrative teaching in radiology - a survey.

    Science.gov (United States)

    Dettmer, S; Weidemann, J; Fischer, V; Wacker, F K

    2015-04-01

    To survey integrative teaching in radiology at German universities. A questionnaire about radiological education was sent electronically to all 37 chairpersons of university radiology departments in Germany. The questions included the course type, teaching methods, concept, perception, and advantages and disadvantages of integrative teaching. Statistical analysis was performed with nonparametric statistics and chi-square test. The survey was considered representative with a return rate of 68 %. Integrative teaching is established at 4/5 of all departments. Integrative teaching is well accepted with an acceptance rate that is significantly higher in so-called "Modellstudiengängen" [model courses of study] (100 %) compared to conventional courses of study (72 %). The advantages of integrative teaching include linking of content (92 %) and preparation for interdisciplinary work (76 %). The disadvantages include high effort (75 %) and time (67 %) for organization. Furthermore, there is a risk that basic radiological facts and knowledge cannot be conveyed and that the visibility of radiology as an independent discipline is lost. Conventional radiological teaching has a similarly high acceptance (84 %) compared to integrative courses (76 %). Integrative teaching has a high acceptance among chairpersons in radiology in Germany despite the greater effort. A good interdisciplinary collaboration is essential for integrative teaching and at the same time this can be conveyed to the students. However, the visibility of radiology as a discipline and the possibility to cover basic radiological content must be ensured. Therefore, both conventional courses and integrative teaching seems reasonable, especially in cross-disciplinary subjects such as radiology. Both integrative teaching and conventional radiological teaching are highly accepted. The advantages include the linking of multidisciplinary content and the preparation for interdisciplinary cooperation

  18. Radiological studies on Egyptian mummies

    International Nuclear Information System (INIS)

    Pahl, W.M.

    1982-01-01

    The goal of this work as part of a mummy study project is to obtain the maximum amount of information through radiological methods with the minimum destruction of the object. For this proven radiological methods were used as well as conventional radiological methods which had not yet been used with mummy research and modern radiological methods using an electronic basis relative to their importance for the study of medical archaeological materials. It is shown that the knowledge which is gained from the use of a combination of classical radiological methods and computed tomography cannot be enhanced by an autopsy of the study objects. Since because of this the objects can be kept in their original condition, a later checking of the results is guaranteed with the possibility of clearing up remaining open questions by means of further developed methods. (orig.) [de

  19. How to Read Your Radiology Report

    Science.gov (United States)

    ... Site Index A-Z How to Read Your Radiology Report Imaging studies such as magnetic resonance imaging ( ... radiology report. top of page Sections of the Radiology Report Type of exam The type of exam ...

  20. WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

    International Nuclear Information System (INIS)

    Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R

    2016-01-01

    Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

  1. WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R [Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

  2. Radiology in the 21st century

    International Nuclear Information System (INIS)

    Carson, P.L.; Seltzer, S.E.; Gore, J.C.; Heiiman, R.S.; Abrams, H.L.; Davis, K.A.; Henkelman, M.R.

    1987-01-01

    On the leading edge in ''high-tech'' medicine, radiology is experiencing several revolutions simultaneously that promise an exciting future. New imaging methods and digital technologies not only offer novel ways to view tissues but also provide opportunities for quantitative evaluation of function and even permit determination of metabolic status. New approaches to technology assessment are being explored that alter the ways in which equipment and procedures are introduced into clinical medicine. With the plethora of radiology services available, the radiologist must serve as a consultant in the triage of patients in radiology and the dissemination of information from radiology. For similar reasons, training in diagnostic radiology may eventually accommodate to the concept of specialization along organ-system lines. Without question, radiology is destined for an exciting period as it moves into the 21st century

  3. Interventional Radiology in Paediatrics.

    Science.gov (United States)

    Chippington, Samantha J; Goodwin, Susie J

    2015-01-01

    As in adult practice, there is a growing role for paediatric interventional radiology expertise in the management of paediatric pathologies. This review is targeted for clinicians who may refer their patients to paediatric interventional radiology services, or who are responsible for patients who are undergoing paediatric interventional radiology procedures. The article includes a brief overview of the indications for intervention, techniques involved and the commonest complications. Although some of the procedures described are most commonly performed in a tertiary paediatric centre, many are performed in most Children's hospitals.

  4. Radiologic technology educators and andragogy.

    Science.gov (United States)

    Galbraith, M W; Simon-Galbraith, J A

    1984-01-01

    Radiologic technology educators are in constant contact with adult learners. However, the theoretical framework that radiologic educators use to guide their instruction may not be appropriate for adults. This article examines the assumptions of the standard instructional theory and the most modern approach to adult education-- andragogy . It also shows how these assumptions affect the adult learner in a radiologic education setting.

  5. Postoperative radiology

    International Nuclear Information System (INIS)

    Burhenne, H.J.

    1989-01-01

    This paper reports on the importance of postoperative radiology. Most surgical procedures on the alimentary tract are successful, but postoperative complications remain a common occurrence. The radiologist must be familiar with a large variety of possible surgical complications, because it is this specialty that is most commonly called on to render a definitive diagnosis. The decision for reoperation, for instance, is usually based on results from radiologic imaging techniques. These now include ultrasonography, CT scanning, needle biopsy, and interventional techniques in addition to contrast studies and nuclear medicine investigation

  6. Radiology

    International Nuclear Information System (INIS)

    Sykora, A.

    2006-01-01

    In this text-book basic knowledge about radiology, biomedical diagnostic methods (radiography, computer tomography), nuclear medicine and safety and radiation protection of personnel on the radiodiagnostic place of work are presented

  7. Federal Radiological Monitoring and Assessment Center (FRMAC), US response to major radiological accidents

    International Nuclear Information System (INIS)

    Mueller, P.G.

    2000-01-01

    During the 1960's and 70's the expanded use of nuclear materials to generate electricity, to provide medical benefits, and for research purposes continued to grow in the United States. While substantial effort went into constructing plants and facilities and providing for a number of redundant backup systems for safety purposes, little effort went into the development of emergency response plans for possible major radiological accidents. Unfortunately, adequate plans and procedures had not been developed to co-ordinate either state or federal emergency response assets and personnel should a major radiological accident occur. This situation became quite evident following the Three Mile Island Nuclear Reactor accident in 1979. An accident of that magnitude had not been adequately prepared for and Pennsylvania's limited emergency radiological resources and capabilities were quickly exhausted. Several federal agencies with statutory responsibilities for emergency response, including the U.S. Environmental Protection Agency (EPA), U.S. Department of Energy (DOE), Federal Emergency Management Agency (FEMA), Nuclear Regulatory Commission (NRC), and others provided extensive assistance and support during the accident. However, the assistance was not fully co-ordinated nor controlled. Following the Three Mile Island incident 13 federal agencies worked co-operatively to develop an agreement called the Federal Radiological Emergency Response Plan (FRERP). Signed in November 1985, this plan delineated the statutory responsibilities and authorities of each federal agency signatory to the FRERP. In the event of a major radiological accident, the FRERP would be activated to ensure that a co-ordinated federal emergency response would be available to respond to any major radiological accident scenario. The FRERP encompasses a wide variety of radiological accidents, not just those stemming from nuclear power plants. Activation of the FRERP could occur from major accidents involving

  8. Radiological Protection Science and Application

    International Nuclear Information System (INIS)

    Janssens, Augustin; ); Mossman, Ken; Morgan, Bill

    2016-01-01

    Since the discovery of radiation at the end of the 19. century, the health effects of exposure to radiation have been studied more than almost any other factor with potential effects on human health. The NEA has long been involved in discussions on the effects of radiation exposure, releasing two reports in 1994 and 2007 on radiological protection science. This report is the third in this state-of-the-art series, examining recent advances in the understanding of radiation risks and effects, particularly at low doses. It focuses on radiobiology and epidemiology, and also addresses the social science aspects of stakeholder involvement in radiological protection decision making. The report summarises the status of, and issues arising from, the application of the International System of Radiological Protection to different types of prevailing circumstances. Reports published by the NEA Committee on Radiation Protection and Public Health (CRPPH) in 1998 and 2007 provided an overview of the scientific knowledge available at that time, as well as the expected results from further research. They also discussed the policy implications that these results could have for the radiological protection system. The 2007 report highlighted challenges posed by developments in relation to medical exposure and by intentions to include the environment (i.e. non-human species), within the scope of the radiological protection system. It also addressed the need to be able to respond to a radiological terrorist attack. This report picks up on where the 1998 and 2007 reports left off, and addresses the state of the art in radiological prevention science and application today. It is divided into five chapters. Firstly, following broadly the structural topics from the 1998 and 2007 reports, the more purely scientific aspects of radiological protection are presented. These include cancer risk of low dose and dose rates, non-cancer effects and individual sensitivity. In view of the increasing

  9. Radiological attacks and accidents. Medical consequences

    International Nuclear Information System (INIS)

    Sakuta, Hidenari

    2007-01-01

    Probability of the occurrence of radiological attacks appears to be elevated after the terrorist attacks against the United States on September 11 in 2001. There are a lot of scenarios of radiological attack: simple radiological device, radiological disperse device (RDD or dirty bomb), attacks against nuclear reactor, improvised nuclear device, and nuclear weapons. Of these, RDD attack is the most probable scenario, because it can be easily made and can generate enormous psychological and economic damages. Radiological incidents are occurring to and fro in the world, including several cases of theft to nuclear facilities and unsuccessful terrorist attacks against them. Recently, a former Russian spy has allegedly been killed using polonium-210. In addition, serious radiological accidents have occurred in Chernobyl, Goiania, and Tokai-mura. Planning, preparation, education, and training exercise appear to be essential factors to cope with radiological attacks and accidents effectively without feeling much anxiety. Triage and psychological first aid are prerequisite to manage and provide effective medial care for mass casualties without inducing panic. (author)

  10. Dosimetric evaluation of PLATO and Oncentra treatment planning systems for High Dose Rate (HDR) brachytherapy gynecological treatments

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Hardev; De La Fuente Herman, Tania; Showalter, Barry; Thompson, Spencer J.; Syzek, Elizabeth J.; Herman, Terence; Ahmad, Salahuddin [Department of Radiation Oncology, Peggy and Charles Stephenson Oklahoma Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 (United States)

    2012-10-23

    This study compares the dosimetric differences in HDR brachytherapy treatment plans calculated with Nucletron's PLATO and Oncentra MasterPlan treatment planning systems (TPS). Ten patients (1 T1b, 1 T2a, 6 T2b, 2 T4) having cervical carcinoma, median age of 43.5 years (range, 34-79 years) treated with tandem and ring applicator in our institution were selected retrospectively for this study. For both Plato and Oncentra TPS, the same orthogonal films anterior-posterior (AP) and lateral were used to manually draw the prescription and anatomical points using definitions from the Manchester system and recommendations from the ICRU report 38. Data input for PLATO was done using a digitizer and Epson Expression 10000XL scanner was used for Oncentra where the points were selected on the images in the screen. The prescription doses for these patients were 30 Gy to points right A (RA) and left A (LA) delivered in 5 fractions with Ir-192 HDR source. Two arrangements: one dwell position and two dwell positions on the tandem were used for dose calculation. The doses to the patient points right B (RB) and left B (LB), and to the organs at risk (OAR), bladder and rectum for each patient were calculated. The mean dose and the mean percentage difference in dose calculated by the two treatment planning systems were compared. Paired t-tests were used for statistical analysis. No significant differences in mean RB, LB, bladder and rectum doses were found with p-values > 0.14. The mean percent difference of doses in RB, LB, bladder and rectum are found to be less than 2.2%, 1.8%, 1.3% and 2.2%, respectively. Dose calculations based on the two different treatment planning systems were found to be consistent and the treatment plans can be made with either system in our department without any concern.

  11. Radical surgical resection and high-dose intraoperative radiation therapy (HDR-IORT) in patients with recurrent gynecologic cancers

    International Nuclear Information System (INIS)

    Gemignani, Mary L.; Alektiar, Kaled M.; Leitao, Mario; Mychalczak, Boris; Chi, Dennis; Venkatraman, Ennapadam; Barakat, Richard R.; Curtin, John P.

    2001-01-01

    Objective: To determine the outcome for patients with recurrent gynecologic tumors treated with radical resection and combined high-dose intraoperative radiation therapy (HDR-IORT). Methods and Materials: Between November 1993 and June 1998, 17 patients with recurrent gynecologic malignancies underwent radical surgical resection and high-dose-rate brachytherapy. The mean age of the study group was 49 years (range 28-72 years). The site of the primary tumor was the cervix in 9 (53%) patients, the uterus in 7 (41%) patients, and the vagina in 1 (6%) patient. The treatment for the primary disease was surgery with or without adjuvant radiation in 14 (82%) patients and definitive radiation in 3 (18%) patients. The current surgery consisted of exenterative surgery in 10 (59%) patients and tumor resection in 7 (41%) patients. Complete gross resection was achieved in 13 (76%) patients. The mean HDR-IORT dose was 14 Gy (range 12-15). Additional radiation in the form of permanent Iodine-125 implant was given to 3 of 4 patients with gross residual disease. The median peripheral dose was 140 Gy. Results: With a median follow-up of 20 months (range 3-65 months), the 3-year actuarial local control (LC) rate was 67%. In patients with complete gross resection, the 3-year LC rate was 83%, compared to 25% in patients with gross residual disease, p<0.01. The 3-year distant metastasis disease-free and overall survival rates were 54% and 54%, respectively. The complications were as follows: gastrointestinal obstruction, 4 (24%); wound complications, 4 (24%); abscesses, 3 (18%); peripheral neuropathy, 3 (18%); rectovaginal fistula, 2 (12%); and ureteral obstruction, 2 (12%). Conclusion: Radical surgical resection and combined IORT for patients with recurrent gynecologic tumors seems to provide a reasonable local-control rate in patients who have failed prior surgery and/or definitive radiation. Patient selection is very important, however, as only those patients with complete gross

  12. Educational course in emergency radiology

    International Nuclear Information System (INIS)

    Velkova, K.; Stoeva, M.; Cvetkova, S.; Hilendarov, A.; Petrova, A.; Stefanov, P.; Simova, E.; Georgieva, V.; Sirakov, N.

    2012-01-01

    Emergency radiology is the part of radiology primarily focused on acute diagnosing conditions in ER patients. This advanced area of radiology improves the quality of care and treatment of patients and of the emergency medicine as a whole. The educational course in Emergency (ER) Radiology is available for medical students in their 8th and 9th semester. The main objective of the ER course is to obtain knowledge about the indications, possibilities and diagnostic value of the contemporary imaging methods in ER cases. Therapeutic methods under imaging control are also covered by the course. The curriculum of the course consists of 6 lectures and 12 practical classes. (authors)

  13. The Radiological Research Accelerator Facility

    International Nuclear Information System (INIS)

    Hall, E.J.; Marino, S.A.

    1990-07-01

    The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) -- formerly the Radiological Research Laboratory (RRL) -- of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). Fifteen different experiments were run during these 12 months, approximately the same as the previous two years. Brief summaries of each experiment are included. Accelerator usage is summarized and development activities are discussed. 7 refs., 4 tabs

  14. Radiological diagnostics of muscle diseases

    International Nuclear Information System (INIS)

    Weber, M.A.; Essig, M.; Kauczor, H.U.

    2007-01-01

    Muscular diseases are a heterogeneous group of diseases with difficult differential diagnosis. This article reviews morphological and functional radiological techniques for assessment of muscular diseases. Morphological techniques can describe edema-like changes, lipomatous and atrophic changes of muscular tissue. However, these imaging signs are often not disease-specific. As a result, clinicians assign radiology a secondary role in the management of muscular diseases. Meanwhile, functional radiological techniques allow the assessment of muscle fiber architecture, skeletal muscle perfusion, myocellular sodium-homoeostasis, lipid- and energy-phosphate metabolism, etc. By detecting and spatially localizing pathophysiological phenomena, these new techniques can increase the role of radiology in muscular diseases. (orig.)

  15. Physics of Radiology

    CERN Document Server

    Johns, Harold Elford

    1983-01-01

    Authority, comprehensivity and a consummate manner of presentation have been hallmarks of The Physics of Radiology since it first saw publication some three decades past. This Fourth Edition adheres to that tradition but again updates the context. It thoroughly integrates ideas recently advanced and practices lately effected. Students and professionals alike will continue to view it, in essence, as the bible of radiological physics.

  16. Radiological aspects of Gaucher disease

    International Nuclear Information System (INIS)

    Katz, Robert; Booth, Tom; Hargunani, Rikin; Wylie, Peter; Holloway, Brian

    2011-01-01

    Advances in imaging and the development of commercially available enzyme therapy have significantly altered the traditional radiology of Gaucher disease. The cost of treatment and need for monitoring response to therapy have magnified the importance of imaging. There are no recent comprehensive reviews of the radiology of this relatively common lysosomal storage disease. This article describes the modern imaging, techniques and radiological manifestations of Gaucher disease. (orig.)

  17. Radiological aspects of Gaucher disease

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Robert; Booth, Tom; Hargunani, Rikin; Wylie, Peter; Holloway, Brian [Royal Free Hospital, Radiology Department, London (United Kingdom)

    2011-12-15

    Advances in imaging and the development of commercially available enzyme therapy have significantly altered the traditional radiology of Gaucher disease. The cost of treatment and need for monitoring response to therapy have magnified the importance of imaging. There are no recent comprehensive reviews of the radiology of this relatively common lysosomal storage disease. This article describes the modern imaging, techniques and radiological manifestations of Gaucher disease. (orig.)

  18. Radiological characterisation - Know your objective

    International Nuclear Information System (INIS)

    Lindow, Veronica; Moeller, Jennifer

    2012-01-01

    When developing a programme for mapping the radiological characteristics of a facility to be decommissioned it is important to take into account the objectives of the programme. Will the results be used to plan for radiological control and selection of appropriate decontamination and dismantling techniques? Will the radiological inventory be used for dimensioning of future waste repositories? These are two examples of the applications for such studies, which could require that a radiological characterisation programme be adapted to provide the data appropriate to the intended use. The level of detail and scope needed for a radiological characterisation will also vary depending on how the data will be used. An application to free-release a facility requires a comprehensive survey and well documented analysis in order to ensure that no radioactive contamination above prescribed levels is present. A bounding calculation to determine the maximum anticipated volumes and activity of radioactive waste requires a different approach. During the past few years, older decommissioning studies for the Swedish nuclear power plants have been updated (or are in the process of being updated). The decommissioning study's main purpose is to estimate the cost for decommissioning. The cost estimation is based on material and activity inventories, which in turn is based on previous and, in some cases, updated radiological characterisations of the facilities. The radiological inventory is an important part of the study as it affects the cost of decommissioning but also the uncertainties and accuracy of the cost estimation. The presentation will discuss the challenges in specifying a radiological characterisation programme with multiple objectives, together with insights on how data delivered can be applied to yield results suitable for the intended purpose, without introducing excessive conservatism. The intent of the presentation is to define issues that can be of use in various aspects

  19. Streamlining interventional radiology admissions: The role of the interventional radiology clinic and physician's assistant

    International Nuclear Information System (INIS)

    White, R.I. Jr.; Rizer, D.M.; Shuman, K.; White, E.J.; Adams, P.; Doyle, K.; Kinnison, M.

    1987-01-01

    During a 5-year period (1982-1987), 376 patients were admitted to an interventional radiology service where they were managed by the senior physician and interventional radiology fellows. Sixty-eight percent of patients were admitted for angioplasty and 32% for elective embolotherapy/diagnostic angiography. A one-half-day, twice weekly interventional radiology clinic and employment of a physician's assistant who performed preadmission history and physicals and wrote orders accounted, in part, for a decrease in hospital stay length from 3.74 days (1982-1983) to 2.41 days (1986-1987). The authors conclude that use of the clinic and the physician's assistant streamlines patient flow and the admitting process and is partially responsible for a decreased length of stay for patients admitted to an interventional radiology service

  20. Radiology. 3. rev. and enl. ed.; Radiologie

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, Maximilian [Klinikum der Universitaet Muenchen (Germany). Inst. fuer Klinische Radiologie; Kuhn, Fritz-Peter [Klinikum Kassel (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Debus, Juergen [Radiologische Universitaetsklinik, Heidelberg (Germany). Abt. Radioonkologie und Strahlentherapie

    2011-07-01

    The text book on radiology covers the following issues: Part A: General radiology: Fundamental physics: radiation biology; radiation protection fundamentals: radiologic methods; radiotherapy; nuclear medicine. Part B: Special radiology: Thorax; heart; urogenital tract and retroperitoneum; vascular system and interventional radiology; esophagus, stomach, small and large intestines; liver, biliary system, pancreas and spleen; mammary glands; central nervous system; spinal cord and spinal canal; basis of the skull, facial bones and eye socket; neck; pediatric imaging diagnostics.

  1. Evidence-based Practice of Radiology.

    Science.gov (United States)

    Lavelle, Lisa P; Dunne, Ruth M; Carroll, Anne G; Malone, Dermot E

    2015-10-01

    Current health care reform in the United States is producing a shift in radiology practice from the traditional volume-based role of performing and interpreting a large number of examinations to providing a more affordable and higher-quality service centered on patient outcomes, which is described as a value-based approach to the provision of health care services. In the 1990 s, evidence-based medicine was defined as the integration of current best evidence with clinical expertise and patient values. When these methods are applied outside internal medicine, the process is called evidence-based practice (EBP). EBP facilitates understanding, interpretation, and application of the best current evidence into radiology practice, which optimizes patient care. It has been incorporated into "Practice-based Learning and Improvement" and "Systems-based Practice," which are two of the six core resident competencies of the Accreditation Council for Graduate Medical Education and two of the 12 American Board of Radiology milestones for diagnostic radiology. Noninterpretive skills, such as systems-based practice, are also formally assessed in the "Quality and Safety" section of the American Board of Radiology Core and Certifying examinations. This article describes (a) the EBP framework, with particular focus on its relevance to the American Board of Radiology certification and maintenance of certification curricula; (b) how EBP can be integrated into a residency program; and (c) the current value and likely place of EBP in the radiology information technology infrastructure. Online supplemental material is available for this article. © RSNA, 2015.

  2. Characterization of subsurface structure at Soultz HDR field by the triaxial drill-bit VSP; Sanjiku drill bit VSP ho ni yoru Soultz HDR field no chika kozo suitei

    Energy Technology Data Exchange (ETDEWEB)

    Asanuma, H; Niitsuma, H; Liu, H [Tohoku University, Sendai (Japan); Baria, R

    1997-10-22

    Triaxial drill-bit VSP (vertical seismic profiling) method is applied to the Soultz HDR (hot dry rock) field, France, where an artificial reservoir is provided inside the bedrock, and the structure inside the rockbed is estimated. An elastic wave detector is installed in the rockbed in this field, and data are acquired having frequency components up to approximately 1kHz. The trajectory of particles due to excavation noise is analyzed, and it is found that the drill-bit is the primary source of noise during excavation and that the SV-wave dominates in the emitted noise. Estimating the subsurface structure aided by the principle of the triaxial drill-bit VSP method, the lower part is detected of the artificial reservoir formed by hydraulic fracturing. As is reported in this paper, when the principle of the subject VSP method is considered, it has to be said that it is quite difficult to employ this method to extensively estimate the subsurface structure on the basis of measurements of the inside of the rockbed. There is a plan for a future study of a technique for accurately and extensively estimating subsurface structures by use of a small number of sensors. 8 refs., 7 figs.

  3. [Instruction in dental radiology

    NARCIS (Netherlands)

    Sanden, W.J.M. van der; Kreulen, C.M.; Berkhout, W.E.

    2016-01-01

    The diagnostic use of oral radiology is an essential part of daily dental practice. Due to the potentially harmful nature of ionising radiation, the clinical use of oral radiology in the Netherlands is framed by clinical practice guidelines and regulatory requirements. Undergraduate students receive

  4. Marketing a Radiology Practice.

    Science.gov (United States)

    Levin, David C; Rao, Vijay M; Flanders, Adam E; Sundaram, Baskaran; Colarossi, Margaret

    2016-10-01

    In addition to being a profession, the practice of radiology is a business, and marketing is an important part of that business. There are many facets to marketing a radiology practice. The authors present a number of ideas on how to go about doing this. Some marketing methods can be directed to both patients and referring physicians. Others should be directed just to patients, while still others should be directed just to referring physicians. Aside from marketing, many of them provide value to both target audiences. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  5. Referral expectations of radiology

    International Nuclear Information System (INIS)

    Smith, W.L.; Altmaier, E.; Berberoglu, L.; Morris, K.

    1989-01-01

    The expectation of the referring physician are key to developing a successful practice in radiology. Structured interviews with 17 clinicians in both community care and academic practice documented that accuracy of the radiologic report was the single most important factor in clinician satisfaction. Data intercorrelation showed that accuracy of report correlated with frequency of referral (r = .49). Overall satisfaction of the referring physician with radiology correlated with accuracy (r = .69), patient satisfaction (r = .36), and efficiency in archiving (r = .42). These data may be weighted by departmental managers to allocate resources for improving referring physician satisfaction

  6. [Controlling instruments in radiology].

    Science.gov (United States)

    Maurer, M

    2013-10-01

    Due to the rising costs and competitive pressures radiological clinics and practices are now facing, controlling instruments are gaining importance in the optimization of structures and processes of the various diagnostic examinations and interventional procedures. It will be shown how the use of selected controlling instruments can secure and improve the performance of radiological facilities. A definition of the concept of controlling will be provided. It will be shown which controlling instruments can be applied in radiological departments and practices. As an example, two of the controlling instruments, material cost analysis and benchmarking, will be illustrated.

  7. Radiology education: a glimpse into the future

    Energy Technology Data Exchange (ETDEWEB)

    Scarsbrook, A.F. [Department of Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford (United Kingdom)]. E-mail: andyscarsbrook1@aol.com; Graham, R.N.J. [Department of Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford (United Kingdom); Perriss, R.W. [Department of Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford (United Kingdom)

    2006-08-15

    The digital revolution in radiology continues to advance rapidly. There are a number of interesting developments within radiology informatics which may have a significant impact on education and training of radiologists in the near future. These include extended functionality of handheld computers, web-based skill and knowledge assessment, standardization of radiological procedural training using simulated or virtual patients, worldwide videoconferencing via high-quality health networks such as Internet2 and global collaboration of radiological educational resources via comprehensive, multi-national databases such as the medical imaging resource centre initiative of the Radiological Society of North America. This article will explore the role of e-learning in radiology, highlight a number of useful web-based applications in this area, and explain how the current and future technological advances might best be incorporated into radiological training.

  8. Radiology education: a glimpse into the future

    International Nuclear Information System (INIS)

    Scarsbrook, A.F.; Graham, R.N.J.; Perriss, R.W.

    2006-01-01

    The digital revolution in radiology continues to advance rapidly. There are a number of interesting developments within radiology informatics which may have a significant impact on education and training of radiologists in the near future. These include extended functionality of handheld computers, web-based skill and knowledge assessment, standardization of radiological procedural training using simulated or virtual patients, worldwide videoconferencing via high-quality health networks such as Internet2 and global collaboration of radiological educational resources via comprehensive, multi-national databases such as the medical imaging resource centre initiative of the Radiological Society of North America. This article will explore the role of e-learning in radiology, highlight a number of useful web-based applications in this area, and explain how the current and future technological advances might best be incorporated into radiological training

  9. The Future of Radiology

    Directory of Open Access Journals (Sweden)

    Alexander R. Margulis

    2011-07-01

    Full Text Available It has been my good fortune to live and practice radiology during a long period of momentous change – to see the transformation of the discipline from a supportive service into a mainstream, essential branch of clinical medicine. I remember wearing red goggles to adapt my vision before performing fluoroscopy; observing the horrible, now thankfully obsolete, practice of ventriculography, which was considered advanced neuroradiology; and performing other, now rarely prescribed procedures, such as double-contrast barium enemas and intravenous pyelography. Witnessing the beginnings of interventional radiology, I suggested its name in an editorial. I also had the good fortune to see the introduction of computed tomography (CT and a technology first known as nuclear magnetic resonance imaging. Together with fellow members of a committee of the American College of Radiology and editors of prestigious radiological journals, I took part in changing the name of the latter modality to MRI, freeing it from threatening implications. Looking back on these experiences, one lesson stands out above all: Innovation and transformation never cease. Looking forward, it is clear that radiology, along with the rest of medicine, is now undergoing further momentous changes that will affect the future of all those already practicing as well as those yet to start their careers.

  10. Radiological Work Planning and Procedures

    CERN Document Server

    Kurtz, J E

    2000-01-01

    Each facility is tasked with maintaining personnel radiation exposure as low as reasonably achievable (ALARA). A continued effort is required to meet this goal by developing and implementing improvements to technical work documents (TWDs) and work performance. A review of selected TWDs from most facilities shows there is a need to incorporate more radiological control requirements into the TWD. The Radioactive Work Permit (RWP) provides a mechanism to place some of the requirements but does not provide all the information needed by the worker as he/she is accomplishing the steps of the TWD. Requiring the engineers, planners and procedure writers to put the radiological control requirements in the work steps would be very easy if all personnel had a strong background in radiological work planning and radiological controls. Unfortunately, many of these personnel do not have the background necessary to include these requirements without assistance by the Radiological Control organization at each facility. In add...

  11. Implementation of a Radiological Safety Coach program

    Energy Technology Data Exchange (ETDEWEB)

    Konzen, K.K. [Safe Sites of Colorado, Golden, CO (United States). Rocky Flats Environmental Technology Site; Langsted, J.M. [M.H. Chew and Associates, Golden, CO (United States)

    1998-02-01

    The Safe Sites of Colorado Radiological Safety program has implemented a Safety Coach position, responsible for mentoring workers and line management by providing effective on-the-job radiological skills training and explanation of the rational for radiological safety requirements. This position is significantly different from a traditional classroom instructor or a facility health physicist, and provides workers with a level of radiological safety guidance not routinely provided by typical training programs. Implementation of this position presents a challenge in providing effective instruction, requiring rapport with the radiological worker not typically developed in the routine radiological training environment. The value of this unique training is discussed in perspective with cost-savings through better radiological control. Measures of success were developed to quantify program performance and providing a realistic picture of the benefits of providing one-on-one or small group training. This paper provides a description of the unique features of the program, measures of success for the program, a formula for implementing this program at other facilities, and a strong argument for the success (or failure) of the program in a time of increased radiological safety emphasis and reduced radiological safety budgets.

  12. Implementation of a Radiological Safety Coach program

    International Nuclear Information System (INIS)

    Konzen, K.K.

    1998-01-01

    The Safe Sites of Colorado Radiological Safety program has implemented a Safety Coach position, responsible for mentoring workers and line management by providing effective on-the-job radiological skills training and explanation of the rational for radiological safety requirements. This position is significantly different from a traditional classroom instructor or a facility health physicist, and provides workers with a level of radiological safety guidance not routinely provided by typical training programs. Implementation of this position presents a challenge in providing effective instruction, requiring rapport with the radiological worker not typically developed in the routine radiological training environment. The value of this unique training is discussed in perspective with cost-savings through better radiological control. Measures of success were developed to quantify program performance and providing a realistic picture of the benefits of providing one-on-one or small group training. This paper provides a description of the unique features of the program, measures of success for the program, a formula for implementing this program at other facilities, and a strong argument for the success (or failure) of the program in a time of increased radiological safety emphasis and reduced radiological safety budgets

  13. Development of radiology in Mongolia

    International Nuclear Information System (INIS)

    Gonchigsuren, D.; Munkhbaatar, D.; Tuvshinjargal, D.; Onkhuudai, P.

    2007-01-01

    Full text: Radiology had been introduced in Mongolia by the establishment of the first X-Ray room at the First State Central Hospital in 1934. First radiologists in Mongolia were invited from the former Soviet Union; V. Sokolov, P. Omelchenko and others worked at the ''Burevestnik'' X-ray equipment of Russian production with high X-ray exposure and low capacity; they could perform only limited arts of Xray studies like fluoroscopy of thorax, stomach, esophagus and roentgenography of skull and extremities. The second X- ray equipment has been presented by the close friend of Lenin, the Director of People's Commissariat of Health Protection of the Soviet Union, Dr. N.A. Semashko; the present had been dedicated to the 10th Anniversary of Mongolian Health Care sector. During the military maneuvers at Khalkhin- Gol in 1939, several province hospitals and military hospitals had been supplied by the Xray equipment. During the period 1959-1960 all province hospitals, specialized hospitals had got X-ray unit. In 1955, Radii 226 had been used at first time in Mongolia for a treatment. In 1959, the State Radiological Clinic had been founded as a branch of X-ray cabinet of the First State Central Hospital. By the initiative of the absolvent of University of Leipzig, German Democratic Republic, Dr. P. Onkhuudai, Laboratory of Nuclear Medicine was established on 31 PstP March 1975 at the First State Central Hospital, which performed urography, thyroid and liver studies using Iod-131, Au-198, Hg-203 isotopes. In 1982, the gamma-camera and radio immunological equipment had been donated by the World Health Organization, and the Laboratory of Nuclear Medicine had been reorganized into Department of Nuclear Laboratory. Afterwards, in 1992 CT and SPECT diagnostics had been introduced at the First State Central Hospital, therefore new possibilities for high quality radiological diagnostic in Mongolia had been created. In 2007 the Siemens Magnetom 0.3 Tesla had been installed at the

  14. Hygiene in radiology

    International Nuclear Information System (INIS)

    Kapp-Schwoerer, A.; Daschner, F.

    1987-01-01

    A survey is given of the hygienic management in radiological departments with special regard to the handling of injections and infusions. It includes prevention of bacterial as well as viral infections. In radiological departments disinfection of X-ray tables is necessary only in exceptional cases. A special proposal for disinfection is added. A safe method of sterilisation of flexible catheders is included, which proved to prevent bacterial infection. (orig.) [de

  15. Emergency radiology

    International Nuclear Information System (INIS)

    Keats, T.E.

    1986-01-01

    This book is the German, translated version of the original published in 1984 in the U.S.A., entitled 'Emergency Radiology'. The publication for the most part is made up as an atlas of the radiological images presenting the findings required for assessment of the emergency cases and their first treatment. The test parts' function is to explain the images and give the necessary information. The material is arranged in seven sections dealing with the skull, the facial part of the skull, the spine, thorax, abdominal region, the pelvis and the hip, and the limbs. With 690 figs [de

  16. ICRP PUBLICATION 121: Radiological Protection in Paediatric Diagnostic and Interventional Radiology

    International Nuclear Information System (INIS)

    Khong, P-L.; Ringertz, H.; Donoghue, V.; Frush, D.; Rehani, M.; Appelgate, K.; Sanchez, R.

    2013-01-01

    Paediatric patients have a higher average risk of developing cancer compared with adults receiving the same dose. The longer life expectancy in children allows more time for any harmful effects of radiation to manifest, and developing organs and tissues are more sensitive to the effects of radiation. This publication aims to provide guiding principles of radiological protection for referring clinicians and clinical staff performing diagnostic imaging and interventional procedures for paediatric patients. It begins with a brief description of the basic concepts of radiological protection, followed by the general aspects of radiological protection, including principles of justification and optimisation. Guidelines and suggestions for radiological protection in specific modalities – radiography and fluoroscopy, interventional radiology, and computed tomography – are subsequently covered in depth. The report concludes with a summary and recommendations. The importance of rigorous justification of radiological procedures is emphasised for every procedure involving ionising radiation, and the use of imaging modalities that are non-ionising should always be considered. The basic aim of optimisation of radiological protection is to adjust imaging parameters and institute protective measures such that the required image is obtained with the lowest possible dose of radiation, and that net benefit is maximised to maintain sufficient quality for diagnostic interpretation. Special consideration should be given to the availability of dose reduction measures when purchasing new imaging equipment for paediatric use. One of the unique aspects of paediatric imaging is with regards to the wide range in patient size (and weight), therefore requiring special attention to optimisation and modification of equipment, technique, and imaging parameters. Examples of good radiographic and fluoroscopic technique include attention to patient positioning, field size and adequate collimation

  17. Radiology Architecture Project Primer.

    Science.gov (United States)

    Sze, Raymond W; Hogan, Laurie; Teshima, Satoshi; Davidson, Scott

    2017-12-19

    The rapid pace of technologic advancement and increasing expectations for patient- and family-friendly environments make it common for radiology leaders to be involved in imaging remodel and construction projects. Most radiologists and business directors lack formal training in architectural and construction processes but are expected to play significant and often leading roles in all phases of an imaging construction project. Avoidable mistakes can result in significant increased costs and scheduling delays; knowledgeable participation and communication can result in a final product that enhances staff workflow and morale and improves patient care and experience. This article presents practical guidelines for preparing for and leading a new imaging architectural and construction project. We share principles derived from the radiology and nonradiology literature and our own experience over the past decade completely remodeling a large pediatric radiology department and building a full-service outpatient imaging center. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  18. Air-kerma evaluation at the maze entrance of HDR brachytherapy facilities

    International Nuclear Information System (INIS)

    Pujades, M C; Granero, D; Vijande, J; Ballester, F; Perez-Calatayud, J; Papagiannis, P; Siebert, F A

    2014-01-01

    In the absence of procedures for evaluating the design of brachytherapy (BT) facilities for radiation protection purposes, the methodology used for external beam radiotherapy facilities is often adapted. The purpose of this study is to adapt the NCRP 151 methodology for estimating the air-kerma rate at the door in BT facilities. Such methodology was checked against Monte Carlo (MC) techniq