Improvement of off-axis SABR plan verification results by using adapted dose reconstruction algorithms for the Octavius 4D system.

abstract：PURPOSE:Anatomical variations occur during head and neck (H&N) radiotherapy treatment. kV cone-beam computed tomography (CBCT) images can be used for daily dose monitoring to assess dose variations owing to anatomic changes. Deep learning methods (DLMs) have recently been proposed to generate pseudo-CT (pCT) from CBCT ...

journal_title：Medical physics

authors： Barateau A,De Crevoisier R,Largent A,Mylona E,Perichon N,Castelli J,Chajon E,Acosta O,Simon A,Nunes JC,Lafond C

更新日期：2020-10-01 00:00:00

abstract：:In a series of in vivo experiments on five adult canines, a small cylindrical permanent magnet (approximately 5-mm diameter x 5 mm long) was magnetically moved under fluoroscopic guidance from an occipital-lobe burr hole to a predetermined destination within the brain and then removed. On three of the animals, dorsal ...

journal_title：Medical physics

authors： Grady MS,Howard MA 3rd,Molloy JA,Ritter RC,Quate EG,Gillies GT

更新日期：1990-05-01 00:00:00

abstract：:The use of characteristic-line radiation from rare-earth targets bombarded by high-energy (up to 1 MeV) electron beams has been evaluated as an x-ray source for dual energy K-edge subtraction imaging of the human coronary arteries. Two characteristic-line x-ray sources, one using the split K alpha 1 and K alpha 2 line...

journal_title：Medical physics

authors： Manning HL,Shefer RE,Klinkowstein RE,Mistretta CA

更新日期：1991-09-01 00:00:00

abstract：PURPOSE:To use machine-learning algorithms and blur measure (BM) operators to automatically detect motion blur in mammograms. Motion blur has been reported to reduce lesion detection performance and mask small abnormalities, resulting in failure to detect them until they reach more advanced stages. Automatic detection ...

journal_title：Medical physics

authors： Kamona N,Loew M

更新日期：2020-04-01 00:00:00

abstract：PURPOSE:Patient-specific QA of highly conformal radiotherapy treatments are usually conducted using 2D or 3D dosimetry of the incident dose distribution in a water-equivalent phantom. However, dosimeters typically used for this task usually lack in either spatial resolution or dose accuracy. The purpose of this work is...

journal_title：Medical physics

authors： Goulet M,Archambault L,Beaulieu L,Gingras L

更新日期：2012-08-01 00:00:00

abstract：PURPOSE:Current on-board imaging systems commonly used by modern linear accelerators (LINACs) have a limited field of view (FOV) for a cone-beam CT (CBCT) scan, which is typically less than 50 cm. Consequently, truncation artifacts often occur for large patients. The goal of this work is to investigate a novel method t...

journal_title：Medical physics

authors： Li T,Li X,Yang Y,Heron DE,Huq MS

更新日期：2010-12-01 00:00:00

abstract：PURPOSE:In the context of fluorescence diffuse optical tomography, determining the optimal way to exploit the time-resolved information has been receiving much attention and different features of the time-resolved signals have been introduced. In this article, the authors revisit and generalize the notion of feature, c...

journal_title：Medical physics

authors： Ducros N,Da Silva A,Dinten JM,Seelamantula CS,Unser M,Peyrin F

更新日期：2010-06-01 00:00:00

abstract：PURPOSE:To provide an overview of the types of adverse events reported to the US Food and Drug Administration (US FDA) for magnetic resonance (MR) systems over a 10-yr period. METHODS:Two reviewers independently reviewed adverse events reported to FDA for MR systems from 1 January 2008 to 31 December 2017 and manually...

journal_title：Medical physics

authors： Delfino JG,Krainak DM,Flesher SA,Miller DL

更新日期：2019-12-01 00:00:00

abstract：:An in vitro radiographic technique which uses saline/iodine displacement has been developed to study the thickness of bone-equivalent and soft-tissue-equivalent materials within atherosclerotic plaques in arterial specimens which have been cut open longitudinally and laid flat. Results concerning the optimization of t...

journal_title：Medical physics

authors： Moreau M,Holdsworth DW,Fenster A

更新日期：1997-01-01 00:00:00

abstract：PURPOSE:Intensity Modulated Neutron Radiotherapy (IMNRT) has been commissioned for clinical use. The number of allowable segments in IMNRT plans is limited by MLC speed. Quality and deliverability of static IMNRT treatment plans using the TG-119 test suite were evaluated to establish guidelines for the number of segmen...

journal_title：Medical physics

authors： Spink R,Burmeister J,Bossenberger T,Snyder M

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted i...

journal_title：Medical physics

authors： Ubeda C,Miranda P,Vano E

更新日期：2015-02-01 00:00:00

abstract：:Routine electron beam quality assurance requires an accurate, yet practical, method of energy characterization. Subtle shifts in beam energy may be produced by the linac bending magnet assembly, and the sensitivity of a commercially available electron beam energy-monitoring device for monitoring these small energy dri...

journal_title：Medical physics

authors： Evans MD,Moftah BA,Olivares M,Podgorsak EB

更新日期：2000-07-01 00:00:00

abstract：:The intensity modulated arc has been proposed as an alternative to tomotherapy. Treatment planing systems more typically model the conventional step and shoot or sliding window dynamic multileaf collimator (DMLC) deliveries, and may not support intensity modulated arc therapy (IMAT). As well, another potential drawbac...

journal_title：Medical physics

authors： MacKenzie MA,Robinson DM

更新日期：2002-10-01 00:00:00

abstract：PURPOSE:The purpose of this study is to quantify the change in monthly VMAT quality assurance (QA) and determine the tests to maintain consistent delivery with a baseline. METHODS:VMAT monthly QA has been performed for over 14 months on two Elekta Synergy LINACs. A baseline was established at acceptance and the monthl...

journal_title：Medical physics

authors： Stenbeck J,Oves S,Gebreamlak W,Alkhatib H

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:This study investigated the dosimetry performance of a linear fiber-optic coupled dosimeter with a sensitive element varying from 3 to 15 cm in length. The dosimeter is comprised of a tissue equivalent plastic scintillating fiber coupled to a photomultiplier tube (PMT). The sensitive element has a length repres...

journal_title：Medical physics

authors： Hoerner M,Hintenlang D

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To develop and evaluate the impact on lesion conspicuity of a software-based x-ray scatter correction algorithm for digital breast tomosynthesis (DBT) imaging into which a precomputed library of x-ray scatter maps is incorporated. METHODS:A previously developed model of compressed breast shapes undergoing mamm...

journal_title：Medical physics

authors： Feng SS,D'Orsi CJ,Newell MS,Seidel RL,Patel B,Sechopoulos I

更新日期：2014-03-01 00:00:00

abstract：:The BEAMnrc/EGSnrc Monte Carlo code system is employed to develop a model of the National Research Council of Canada primary standard of absorbed dose to tissue in a beta radiation field, comprising an extrapolation chamber and 90Sr/90Y beta source. We benchmark the model against the measured response of the chamber i...

journal_title：Medical physics

authors： Selvam TP,Saull PR,Rogers DW,National Research Council of Canada.

更新日期：2005-10-01 00:00:00

abstract：:Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides 137Cs, 125I, 192Ir, 103Pd, and 169Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of pha...

journal_title：Medical physics

authors： Melhus CS,Rivard MJ

更新日期：2006-06-01 00:00:00

abstract：:A new high-resolution detector has been developed for use in a slot-scanned digital mammography system. The detector is a hybrid device that consists of a CCD operating in time-delay integration mode that is bonded to a 150-microm-thick CdZnTe photoconductor array. The CCD was designed with a detector element pitch of...

journal_title：Medical physics

authors： Mainprize JG,Ford NL,Yin S,Gordon EE,Hamilton WJ,Tümer TO,Yaffe MJ

更新日期：2002-12-01 00:00:00

abstract：PURPOSE:Megavoltage grid therapy is currently delivered with step-and-shoot multisegment techniques or using a high attenuation block with divergent holes. However, the commercial availability of grid blocks is limited, their construction is difficult, and step-and-shoot techniques require longer treatment times and ar...

journal_title：Medical physics

authors： Almendral P,Mancha PJ,Roberto D

更新日期：2013-05-01 00:00:00

abstract：:The head-scatter factors H were examined for four different linear accelerators and were found to be similar at field sizes larger than 3 x 3 cm2. Sharply reduced values for small collimator openings were observed for all the accelerators. It is concluded that the head-scatter (or collimator-scatter) factor has two ma...

journal_title：Medical physics

authors： Zhu TC,Bjärngard BE

更新日期：1994-01-01 00:00:00

abstract：PURPOSE:MR thermometry based on the proton resonance frequency shift (PRFS) is the most commonly used method for the monitoring of thermal therapies. As the chemical shift of water protons is temperature dependent, the local temperature variation (relative to an initial baseline) may be calculated from time-dependent p...

journal_title：Medical physics

authors： Viallon M,Terraz S,Roland J,Dumont E,Becker CD,Salomir R

更新日期：2010-04-01 00:00:00

abstract：PURPOSE:To apply the recent code of practice from the IAEA/AAPM, TRS 483, to helical tomotherapy (HT) for reference and relative dosimetry obtaining correction factors for the Exradin A1SL ionization chamber. METHODS:The beam quality correction factor for the A1SL chamber was obtained through three different approache...

journal_title：Medical physics

authors： Lopes MDC,Santos T,Ventura T,Capela M

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:To construct a Monte Carlo (MC)-based simulation model for analyzing the dependence of tumor oxygen distribution on different variables related to tumor vasculature [blood velocity, vessel-to-vessel proximity (vessel proximity), and inflowing oxygen partial pressure (pO2)]. METHODS:A voxel-based tissue model c...

journal_title：Medical physics

authors： Lagerlöf JH,Kindblom J,Bernhardt P

更新日期：2014-09-01 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：:The purpose of this study was to investigate if interfraction and intrafraction motion in free-breathing and gated lung IMRT can lead to systematic dose differences between 3DCT and 4DCT. Dosimetric effects were studied considering the breathing pattern of three patients monitored during the course of their treatment ...

journal_title：Medical physics

authors： Seco J,Sharp GC,Wu Z,Gierga D,Buettner F,Paganetti H

更新日期：2008-01-01 00:00:00

abstract：PURPOSE:To evaluate a commercial volumetric modulated arc therapy (VMAT), using multiple noncoplanar arcs, for linac-based cranial radiosurgery, as well as evaluate the combined accuracy of the VMAT dose calculations and delivery. METHODS:Twelve patients with cranial lesions of variable size (0.1-29 cc) and two multip...

journal_title：Medical physics

authors： Audet C,Poffenbarger BA,Chang P,Jackson PS,Lundahl RE,Ryu SI,Ray GR

更新日期：2011-11-01 00:00:00

abstract：:Using stable materials capable of mimicking any soft tissues of the human body--quantitatively with respect to speed of sound, density, and attenuation coefficient and semiquantitatively with respect to scatter--we have constructed a torso section phantom containing simulated bowel gas, kidney, kidney fat pad, liver, ...

journal_title：Medical physics

authors： Madsen EL,Zagzebski JA,Ghilardi-Netto T

更新日期：1980-01-01 00:00:00

abstract：:A new type of radiographic film, EDR (extended dose range) film, has been recently become available for film dosimetry. It is particularly attractive for composite isodose verification of intensity modulated radiation therapy because of its low sensitivity relative to the more common Kodak XV film. For XV film, the re...

journal_title：Medical physics

authors： Zhu XR,Yoo S,Jursinic PA,Grimm DF,Lopez F,Rownd JJ,Gillin MT

更新日期：2003-05-01 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