Poster - Thur Eve - 09: Novel radiation safety challenges of a brachytherapy redevelopment at the Credit Valley Hospital.

abstract：:The ratio between scatter dose and scatter kerma for points on the central axis of 15-MV x-ray beams has been examined by Monte Carlo calculations. This ratio, beta'S, behaves differently from that between the primary dose and kerma, beta'p. Both the primary and scatter components of beta' undergo an initial rapid bui...

journal_title：Medical physics

authors： Hannallah D,Zhu TC,Bjärngard BE

更新日期：1996-11-01 00:00:00

abstract：:This article is the first in a series on the calculation of electron dose using multiple-scattering theory. In it we develop a unified theory, which we term Gaussian multiple-scattering theory, starting from a number of contributions already in the literature: the Fermi-Eyges multiple-scattering theory, the Yang path ...

journal_title：Medical physics

authors： Jette D

更新日期：1988-03-01 00:00:00

abstract：:The use of electronic portal imaging devices (EPIDs) is a promising method for the dosimetric verification of external beam, megavoltage radiation therapy-both pretreatment and in vivo. In this study, a previously developed EPID back-projection algorithm was modified for IMRT techniques and applied to an amorphous sil...

journal_title：Medical physics

authors： Wendling M,Louwe RJ,McDermott LN,Sonke JJ,van Herk M,Mijnheer BJ

更新日期：2006-02-01 00:00:00

abstract：PURPOSE:To present a system for robotic 4D ultrasound (US) imaging concurrent with radiotherapy beam delivery and estimate the proportion of liver stereotactic ablative body radiotherapy (SABR) cases in which robotic US image guidance can be deployed without interfering with clinically used VMAT beam configurations. M...

journal_title：Medical physics

authors： Schlosser J,Gong RH,Bruder R,Schweikard A,Jang S,Henrie J,Kamaya A,Koong A,Chang DT,Hristov D

更新日期：2016-11-01 00:00:00

abstract：PURPOSE:The hematopoietically active tissues of skeletal bone marrow are a prime target for computational dosimetry given potential risks of leukemia and, at higher dose levels, acute marrow toxicity. The complex three-dimensional geometry of trabecular spongiosa, however, complicates schema for dose assessment in such...

journal_title：Medical physics

authors： Geyer AM,Schwarz BC,Hobbs RF,Sgouros G,Bolch WE

更新日期：2017-01-01 00:00:00

abstract：PURPOSE:To quantify detector perturbation effects in megavoltage small photon fields and support the theoretical explanation on the nature of quality correction factors in these conditions. METHODS:In this second paper, a modern approach to radiation dosimetry is defined for any detector and applied to small photon fi...

journal_title：Medical physics

authors： Bouchard H,Kamio Y,Palmans H,Seuntjens J,Duane S

更新日期：2015-10-01 00:00:00

abstract：:Generating an optimized radiation treatment plan requires understanding the factors affecting tumour control. Mathematical models of tumour dynamics may help in future studies of factors predicting tumor sensitivity to radiotherapy. In this study, a time-dependent differential model, incorporating biological cancer ma...

journal_title：Medical physics

authors： Campbell A,Davidson M,Lock M,Wong E

更新日期：2008-07-01 00:00:00

abstract：PURPOSE:To achieve more translatable preclinical research results, small animal irradiation needs to more closely simulate human radiotherapy. Although the clinical gold standard is intensity-modulated radiation therapy (IMRT), the direct translation of this method for small animals is impractical. In this study we des...

journal_title：Medical physics

authors： Woods K,Nguyen D,Neph R,Ruan D,O'Connor D,Sheng K

更新日期：2019-12-01 00:00:00

abstract：:The dosimetric characteristics of a new dedicated radiosurgical treatment unit are systematically measured in terms of its percent depth dose, beam profile, and relative scatter factor. High-resolution diode detector, mini-ion-chamber detector, and conventional Kodak XV films are used to measure dosimetric data for a ...

journal_title：Medical physics

authors： Yin FF,Zhu J,Yan H,Gaun H,Hammoud R,Ryu S,Kim JH

更新日期：2002-08-01 00:00:00

abstract：PURPOSE:Intracavitary accelerated partial breast irradiation (APBI) has become a popular treatment for early stage breast cancer in recent years due to its shortened course of treatment and simplified treatment planning compared to traditional external beam breast conservation therapy. However, the exit dose to the ski...

journal_title：Medical physics

authors： Raffi JA,Davis SD,Hammer CG,Micka JA,Kunugi KA,Musgrove JE,Winston JW Jr,Ricci-Ott TJ,DeWerd LA

更新日期：2010-06-01 00:00:00

abstract：PURPOSE:To automatically detect and isolate areas of low and high stiffness temporal stability in shear wave elastography (SWE) image sequences and define their impact in chronic liver disease (CLD) diagnosis improvement by means of clinical examination study and deep learning algorithm employing convolutional neural n...

journal_title：Medical physics

authors： Gatos I,Tsantis S,Spiliopoulos S,Karnabatidis D,Theotokas I,Zoumpoulis P,Loupas T,Hazle JD,Kagadis GC

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:The authors have developed a system that monitors intrafractional target motion perpendicular to the treatment beam with the aid of radioopaque markers by means of separating kV image and megavoltage (MV) treatment field on a single flat-panel detector. METHODS:They equipped a research Siemens Artiste linear a...

journal_title：Medical physics

authors： Fast MF,Krauss A,Oelfke U,Nill S

更新日期：2012-01-01 00:00:00

abstract：PURPOSE:Patient-specific IMRT QA measurements are important components of processes designed to identify discrepancies between calculated and delivered radiation doses. Discrepancy tolerance limits are neither well defined nor consistently applied across centers. The AAPM TG-218 report provides a comprehensive review a...

journal_title：Medical physics

authors： Miften M,Olch A,Mihailidis D,Moran J,Pawlicki T,Molineu A,Li H,Wijesooriya K,Shi J,Xia P,Papanikolaou N,Low DA

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:A joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and ...

journal_title：Medical physics

authors： Ma Y,Vijande J,Ballester F,Tedgren ÅC,Granero D,Haworth A,Mourtada F,Fonseca GP,Zourari K,Papagiannis P,Rivard MJ,Siebert FA,Sloboda RS,Smith R,Chamberland MJP,Thomson RM,Verhaegen F,Beaulieu L

更新日期：2017-11-01 00:00:00

abstract：:In order to determine accurately the relative x-ray intensities transmitted through the different steps of an aluminum stepwedge and incident on an image intensifier (II)-TV digital system, we used a 100-mm camera which was attached to the II output. The characteristic curves of an II-TV digital system, which relate t...

journal_title：Medical physics

authors： Fujita H,Doi K

更新日期：1986-11-01 00:00:00

abstract：PURPOSE:Potential collision between the patient∕couch and the gantry could delay the start of the treatment and reduce clinical efficiency. The ability to accurately detect possible collisions during the treatment planning phase is desired. Such collision detection should account for the specific proton gantry design, ...

journal_title：Medical physics

authors： Zou W,Lin H,Plastaras JP,Wang H,Bui V,Vapiwala N,McDonough J,Tochner Z,Both S

更新日期：2012-11-01 00:00:00

abstract：:Skeletal dosimetry based on microCT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the microCT images for skeletal dosimetry, spongiosa voxels in the skele...

journal_title：Medical physics

authors： Kramer R,Khoury HJ,Vieira JW,Robson Brown KA

更新日期：2009-11-01 00:00:00

abstract：PURPOSE:Accurate detection of pulmonary nodules remains a technical challenge in computer-aided diagnosis systems because some nodules may adhere to the blood vessels or the lung wall, which have low contrast compared to the surrounding tissues. In this paper, the analysis of typical shape features of candidate nodules...

journal_title：Medical physics

authors： Wang B,Tian X,Wang Q,Yang Y,Xie H,Zhang S,Gu L

更新日期：2015-03-01 00:00:00

abstract：PURPOSE:The use of 4D computed tomography (4D-CT) of the lung is important in lung cancer radiotherapy for tumor localization and treatment planning. Sometimes, dense sampling is not acquired along the superior-inferior direction. This disadvantage results in an interslice thickness that is much greater than in-plane v...

journal_title：Medical physics

authors： Zhang Y,Wu X,Yang W,Feng Q,Chen W

更新日期：2014-11-01 00:00:00

abstract：:The aim of the current study was to (a) provide normalized dose data for the estimation of the radiation dose from upper gastrointestinal tract contrast (UGIC) studies carried out to infants and (b) estimate the average patient dose and risks associated with radiation from UGIC examinations performed in our institutio...

journal_title：Medical physics

authors： Damilakis J,Stratakis J,Raissaki M,Perisinakis K,Kourbetis N,Gourtsoyiannis N

更新日期：2006-04-01 00:00:00

abstract：PURPOSE:The combination of nonhuman primates (NHPs) with the state-of-the-art molecular imaging technologies allows for within-subject longitudinal research aiming at gaining new insights into human normal and disease conditions and provides an ideal foundation for future translational studies of new diagnostic tools, ...

journal_title：Medical physics

authors： Xie T,Chen X,Zaidi H

更新日期：2020-09-01 00:00:00

abstract：PURPOSE:The purpose of this study is to adapt an equivalent source model originally developed for conventional CT Monte Carlo dose quantification to the radiation oncology context and validate its application for evaluating concomitant dose incurred by a kilovoltage (kV) cone-beam CT (CBCT) system integrated into a lin...

journal_title：Medical physics

authors： McMillan K,McNitt-Gray M,Ruan D

更新日期：2013-11-01 00:00:00

abstract：:The immediate goal of clinically based x-ray-transmission computed tomography (CT) is to provide a measurement of the x-ray linear attenuation coefficient in cross section with the ultimate goal of impacting on patient management and care. To do this with the accuracy needed for clinical goals requires the careful int...

journal_title：Medical physics

authors： McCullough EC,Payne JT

更新日期：1977-03-01 00:00:00

abstract：:Attenuation correction is an essential component of the long chain of data correction techniques required to achieve the full potential of quantitative positron emission tomography (PET) imaging. The development of combined PET/magnetic resonance imaging (MRI) systems mandated the widespread interest in developing nov...

journal_title：Medical physics

authors： Mehranian A,Arabi H,Zaidi H

更新日期：2016-03-01 00:00:00

abstract：:Lag and residual contrast have been quantified in an amorphous selenium (a-Se) active-matrix flat-panel imager (AMFPI) as a function of frame time, kilovoltage (kV) and megavoltage (MV) x-ray photon energies and amount of radiation incident on the detector. The AMFPI contains a 200 microm thick a-Se layer deposited on...

journal_title：Medical physics

authors： Schroeder C,Stanescu T,Rathee S,Fallone BG

更新日期：2004-05-01 00:00:00

abstract：PURPOSE:The primary objective of this work is to measure the secondary neutron field produced by an uncollimated proton pencil beam impinging on different tissue-equivalent phantom materials using organic scintillation detectors. Additionally, the Monte Carlo code mcnpx-PoliMi was used to simulate the detector response...

journal_title：Medical physics

authors： Clarke SD,Pryser E,Wieger BM,Pozzi SA,Haelg RA,Bashkirov VA,Schulte RW

更新日期：2016-11-01 00:00:00

abstract：:The absorbed dose values determined with the Exradin and PTW-Markus plane-parallel chambers were compared to the values obtained with the ferrous sulphate dosimetry for a number of the Philips SL25 and the Therac 20 electron beams. For the plane-parallel chambers, the cavity-gas calibration factor Ngaspp, was derived ...

journal_title：Medical physics

authors： Xu Z,Li H,Almond PR,Guan TY

更新日期：1996-03-01 00:00:00

abstract：:The mixed-field dosimetry for 252Cf Applicator Tube (AT) type medical sources available from Oak Ridge National Laboratory (ORNL) has been characterized using ionization chambers, a GM counter, and Monte Carlo methods. Unlike the AAPM Task Group No. 43 (TG-43), specification of dose to muscle instead of water is recom...

journal_title：Medical physics

authors： Rivard MJ

更新日期：1999-08-01 00:00:00

abstract：:Volumetric modulated arc therapy (VMAT) has recently been used to improve the dose distribution and efficiency of treatment delivery over the standard intensity-modulated radiotherapy (IMRT) technique. This study compares the dosimetry between RapidArc plan and standard IMRT plan for head and neck cancer. Three head a...

journal_title：Medical physics

authors： Jiang R,Fleck A,Schaly B,Charland P,Zhan L,Alliet K,Rachakonda R,Osei E

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:To compare beam characteristics of superficial X-rays with 6 MeV Electrons for the purpose of replacing superficial treatments with electron fields for skin lesions. METHODS:Electron beam cutouts were made with 12mm thickness cerrobend in diameters 2-5 cm to match superficial X-ray machine cones. Central axis ...

journal_title：Medical physics

authors： Avadhani J,Sasidharan S,Carton C,Lowen M,Klapproth T,Licitra C

更新日期：2012-06-01 00:00:00