Monte Carlo aided room scatter studies in the primary air kerma strength standardization of a remote afterloading 192Ir HDR source.

abstract：:The quality of radiation therapy delivered for treating cancer patients is related to set-up errors and organ motion. Due to the margins needed to ensure adequate target coverage, many breast cancer patients have been shown to develop late side effects such as pneumonitis and cardiac damage. Breathing-adapted radiatio...

journal_title：Physics in medicine and biology

authors： Kakar M,Nyström H,Aarup LR,Nøttrup TJ,Olsen DR

更新日期：2005-10-07 00:00:00

abstract：:Depth-dose distributions were calculated for thermal and epithermal neutron fluence and capture gamma ray dose rates using a two-dimensional neutron-coupled gamma-ray transport code (DOT 3.5) for gadolinium neutron capture therapy. The results show that (i) a capture gamma-ray dose rate of 10 Gy h-1 was obtained with ...

journal_title：Physics in medicine and biology

authors： Matsumoto T

更新日期：1992-01-01 00:00:00

abstract：:The practical use of a discrete vessel thermal model for hyperthermia treatment planning requires a number of choices with respect to the unknown part of the patient's vasculature. This work presents a study of the thermal effects of blood flow in a simple tissue geometry with a detailed artificial vessel network. The...

journal_title：Physics in medicine and biology

authors： Van Leeuwen GM,Kotte AN,Raaymakers BW,Lagendijk JJ

更新日期：2000-04-01 00:00:00

abstract：:A novel approach to read out radiochromic film was introduced recently by the manufacturer of GafChromic film. In this study, the performance of this triple-channel film dosimetry method was compared against the conventional single-red-channel film dosimetry procedure, with and without inclusion of a pre-irradiation (...

journal_title：Physics in medicine and biology

authors： van Hoof SJ,Granton PV,Landry G,Podesta M,Verhaegen F

更新日期：2012-07-07 00:00:00

abstract：:Prompt γ-ray imaging with a knife-edge shaped slit camera provides the possibility of verifying proton beam range in tumor therapy. Dedicated experiments regarding the characterization of the camera system have been performed previously. Now, we aim at implementing the prototype into clinical application of monitoring...

journal_title：Physics in medicine and biology

authors： Priegnitz M,Barczyk S,Nenoff L,Golnik C,Keitz I,Werner T,Mein S,Smeets J,Vander Stappen F,Janssens G,Hotoiu L,Fiedler F,Prieels D,Enghardt W,Pausch G,Richter C

更新日期：2016-11-21 00:00:00

abstract：:Effects of different scatter compensation methods incorporated in fully 3D iterative reconstruction are investigated. The methods are: (i) the inclusion of an 'ideal scatter estimate' (ISE); (ii) like (i) but with a noiseless scatter estimate (ISE-NF); (iii) incorporation of scatter in the point spread function during...

journal_title：Physics in medicine and biology

authors： Beekman FJ,Kamphuis C,Frey EC

更新日期：1997-08-01 00:00:00

abstract：:A photon diffusion model has been developed to calculate the steady-state spatially resolved fluorescence from pencil beam excitation in layered tissue. The model allows the calculation of both the excitation reflectance and the fluorescence escape for an arbitrary continuous depth distribution of tissue optical prope...

journal_title：Physics in medicine and biology

authors： Hyde DE,Farrell TJ,Patterson MS,Wilson BC

更新日期：2001-02-01 00:00:00

abstract：PURPOSE:A system for long-length intraoperative imaging is reported based on longitudinal motion of an O-arm gantry featuring a multi-slot collimator. We assess the utility of long-length tomosynthesis and the geometric accuracy of 3D image registration for surgical guidance and evaluation of long spinal constructs. M...

journal_title：Physics in medicine and biology

authors： Zhang X,Uneri A,Wu P,Ketcha MD,Jones C,Huang Y,Lo SL,Helm PA,Siewerdsen JH

更新日期：2021-01-21 00:00:00

abstract：:In modern radiotherapy the verification of complex treatments plans is often performed in inhomogeneous or even anthropomorphic phantoms. For dose verification small detectors are necessary and therefore alanine detectors are most suitable. Though the response of alanine for a wide range of clinical photon energies in...

journal_title：Physics in medicine and biology

authors： von Voigts-Rhetz P,Anton M,Vorwerk H,Zink K

更新日期：2016-02-07 00:00:00

abstract：:A cost-effective method employing polysulphone, nalidixic acid, 8-methoxypsoralen and phenothiazine as UV dosimeters is presented for evaluating the UV spectrum. The exposure measured by each dosimeter is a function of the source spectrum and the spectral response of the material. Each material has a different spectra...

journal_title：Physics in medicine and biology

authors： Parisi AV,Wong JC,Moore GI

更新日期：1997-01-01 00:00:00

abstract：:Four-dimensional volumetric modulated arc therapy (4D VMAT) is a treatment strategy for lung cancers that aims to exploit relative target and tissue motion to improve organ at risk (OAR) sparing. The algorithm incorporates the entire patient respiratory cycle using 4D CT data into the optimization process. Resulting t...

journal_title：Physics in medicine and biology

authors： Chin E,Loewen SK,Nichol A,Otto K

更新日期：2013-02-21 00:00:00

abstract：:Over the past few years there has been much interest in the development of three-dimensional dosimeters to determine the complex absorbed dose distribution in modern radiotherapy techniques such as IMRT and IGRT. In routine methods used for three-dimensional dosimetry, polymer gels are commonly used. Recently, a novel...

journal_title：Physics in medicine and biology

authors： Mostaar A,Hashemi B,Zahmatkesh MH,Aghamiri SM,Mahdavi SR

更新日期：2010-02-07 00:00:00

abstract：:Investigate 3D (spatial and temporal) convolutional neural networks (CNNs) for real-time on-the-fly magnetic resonance imaging (MRI) reconstruction. In particular, we investigated the applicability of training CNNs on a patient-by-patient basis for the purpose of lung tumor segmentation. Data were acquired with our 3 ...

journal_title：Physics in medicine and biology

authors： Dietz B,Yun J,Yip E,Gabos Z,Fallone BG,Wachowicz K

更新日期：2019-09-23 00:00:00

abstract：:Grating-based x-ray phase-contrast imaging provides three simultaneous image channels originating from a single image acquisition. While the phase signal provides direct access to the electron density in tomography, there is additional information on sub-resolutional structural information which is called dark-field s...

journal_title：Physics in medicine and biology

authors： Braig EM,Pfeiffer D,Willner M,Sellerer T,Taphorn K,Petrich C,Scholz J,Petzold L,Birnbacher L,Dierolf M,Pfeiffer F,Herzen J

更新日期：2020-09-18 00:00:00

abstract：:Heating induced near deep brain stimulation (DBS) lead electrodes during magnetic resonance imaging with a 3 T transceive head coil was measured, modeled, and imaged in three cadaveric porcine heads (mean body weight = 85.47 ± 3.19 kg, mean head weight = 5.78 ± 0.32 kg). The effect of the placement of the extra-crania...

journal_title：Physics in medicine and biology

authors： Shrivastava D,Abosch A,Hughes J,Goerke U,DelaBarre L,Visaria R,Harel N,Vaughan JT

更新日期：2012-09-07 00:00:00

abstract：:The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and w...

journal_title：Physics in medicine and biology

authors： Craft D,Halabi T,Bortfeld T

更新日期：2005-12-21 00:00:00

abstract：:Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units ...

journal_title：Physics in medicine and biology

authors： Salter BJ,Sarkar V,Wang B,Shukla H,Szegedi M,Rassiah-Szegedi P

更新日期：2011-04-07 00:00:00

abstract：:Until now, no matrix transducer has been realized for 3D transesophageal echocardiography (TEE) in pediatric patients. In 3D TEE with a matrix transducer, the biggest challenges are to connect a large number of elements to a standard ultrasound system, and to achieve a high volume rate (>200 Hz). To address these issu...

journal_title：Physics in medicine and biology

authors： Bera D,Raghunathan SB,Chen C,Chen Z,Pertijs MAP,Verweij MD,Daeichin V,Vos HJ,van der Steen AFW,de Jong N,Bosch JG

更新日期：2018-03-29 00:00:00

abstract：:Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the ima...

journal_title：Physics in medicine and biology

authors： Zhao C,Konstantinidis AC,Zheng Y,Anaxagoras T,Speller RD,Kanicki J

更新日期：2015-12-07 00:00:00

abstract：:Monolithic scintillation detectors for positron emission tomography and single-photon emission computed tomography (SPECT) imaging have many advantages over pixelated detectors. The use of monolithic crystals allows for reducing the scintillator cost per unit volume and increasing the sensitivity along with the energy...

journal_title：Physics in medicine and biology

authors： España S,Deprez K,Van Holen R,Vandenberghe S

更新日期：2013-07-21 00:00:00

abstract：:Existing studies have suggested some debate on whether the quality of radiation that delivers dose outside of the primary field of a radiotherapy photon beam can be considered the same as that inside the primary field. We used a Monte Carlo approach to simulate the electron fluence differential in energy inside a wate...

journal_title：Physics in medicine and biology

authors： Kirkby C,Field C,MacKenzie M,Syme A,Fallone BG

更新日期：2007-06-21 00:00:00

abstract：:In recent years, particle therapy has become a widely accepted form of cancer treatment and technological advances in beam delivery technology (i.e. pencil beam scanning (PBS)) have enabled the application of highly conformal dose distributions to static targets. Current research focuses on the possibilities for the t...

journal_title：Physics in medicine and biology

authors： Bernatowicz K,Lomax AJ,Knopf A

更新日期：2013-11-21 00:00:00

abstract：:The presence of motion artifacts is a typical problem in thoracic imaging. However, synchronizing the respiratory cycle with computed tomography (CT) image acquisition can reduce these artifacts. We currently employ a method of in vivo respiratory-gated micro-CT imaging for small laboratory animals (mice). This proced...

journal_title：Physics in medicine and biology

authors： Walters EB,Panda K,Bankson JA,Brown E,Cody DD

更新日期：2004-09-07 00:00:00

abstract：:Dynamic modulation can be affected by inaccuracies when the required acceleration is larger than the highest allowed by the mechanical characteristics of the whole apparatus. In this study, inertia effects have been investigated with regard to the single absorber 1D modulation, analysing primarily how the acceleration...

journal_title：Physics in medicine and biology

authors： Corletto D,Broggi S,Fiorino C,Mangili P,Calandrino R,Lev A,Gennari D,Rudello F

更新日期：1999-11-01 00:00:00

abstract：:Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry ...

journal_title：Physics in medicine and biology

authors： Afsharpour H,Landry G,D'Amours M,Enger S,Reniers B,Poon E,Carrier JF,Verhaegen F,Beaulieu L

更新日期：2012-06-07 00:00:00

abstract：:Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to in...

journal_title：Physics in medicine and biology

authors： Petoussi-Henss N,Zanki M,Fill U,Regulla D

更新日期：2002-01-07 00:00:00

abstract：:The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work was to develop a systematic method that yields accurate and patient-specific RSPs by combining (1) pre-treatment x-ray CT and (2) daily proton radiography of the patient. The me...

journal_title：Physics in medicine and biology

authors： Collins-Fekete CA,Brousmiche S,Hansen DC,Beaulieu L,Seco J

更新日期：2017-08-03 00:00:00

abstract：:This study presents a combined small animal holding fixture system, termed a 'bridge capsule', which provides for small animal re-fixation with positional reproducibility. This system comprises separate holding fixtures for the head and lower body and a connecting part to a gas anesthesia system. A mouse is fixed in p...

journal_title：Physics in medicine and biology

authors： Kokuryo D,Kimura Y,Obata T,Yamaya T,Kawamura K,Zhang MR,Kanno I,Aoki I

更新日期：2010-07-21 00:00:00

abstract：:The purpose of this study was to derive a complete set of correction and perturbation factors for output factors (OF) and dose profiles. Modern small field detectors were investigated including a plastic scintillator (Exradin W1, SI), a liquid ionization chamber (microLion 31018, PTW), an unshielded diode (Exradin D1V...

journal_title：Physics in medicine and biology

authors： Papaconstadopoulos P,Tessier F,Seuntjens J

更新日期：2014-10-07 00:00:00

abstract：:This paper presents a method to obtain the pencil-beam kernels that characterize a megavoltage photon beam generated in a flattening filter free (FFF) linear accelerator (linac) by deconvolution from experimental measurements at different depths. The formalism is applied to perform independent dose calculations in mod...

journal_title：Physics in medicine and biology

authors： Azcona JD,Barbés B,Wang L,Burguete J

更新日期：2016-01-07 00:00:00