Prediction of dose-volume histograms in nasopharyngeal cancer IMRT using geometric and dosimetric information.

abstract：:Fast calculation or simulation of the ablation zone induced by radiofrequency ablation (RFA) has a critical role in hepatic RFA planning and therapy. However, it remains challenging to approximate the ablation zone in real time, especially when more than one probe is involved in one ablation session. This paper presen...

journal_title：Physics in medicine and biology

authors： Chen R,Zhang J,Kong D,Lou Q,Lu F

更新日期：2021-01-27 00:00:00

abstract：:The dynamic magnetization of immobilized spherical single-domain magnetic nanoparticles (MNPs) with uniaxial or cubic magnetocrystalline anisotropy was studied computationally by executing simulations based on the Landau-Lifshitz-Gilbert (LLG) equation. For situations when a static magnetic field was suddenly applied ...

journal_title：Physics in medicine and biology

authors： Zhao Z,Garraud N,Arnold DP,Rinaldi C

更新日期：2020-01-17 00:00:00

abstract：:In multiple plan adaptive radiotherapy (ART) strategies of bladder cancer, a library of plans corresponding to different bladder volumes is created based on images acquired in early treatment sessions. Subsequently, the plan for the smallest PTV safely covering the bladder on cone-beam CT (CBCT) is selected as the pla...

journal_title：Physics in medicine and biology

authors： Chai X,van Herk M,Betgen A,Hulshof M,Bel A

更新日期：2012-06-21 00:00:00

abstract：:This work aims at developing a generic virtual source model (VSM) preserving all existing correlations between variables stored in a Monte Carlo pre-computed phase space (PS) file, for dose calculation and high-resolution portal image prediction. The reference PS file was calculated using the PENELOPE code, after the ...

journal_title：Physics in medicine and biology

authors： Chabert I,Barat E,Dautremer T,Montagu T,Agelou M,Croc de Suray A,Garcia-Hernandez JC,Gempp S,Benkreira M,de Carlan L,Lazaro D

更新日期：2016-07-21 00:00:00

abstract：:The trend towards conformal, intensity modulated radiotherapy treatments has established the need for a true integrating dosimeter. In traditional radiotherapy, radiographic film dosimetry is commonly used. The accuracy and reproducibility of film optical density as an indicator of dose is influenced by several variab...

journal_title：Physics in medicine and biology

authors： Suchowerska N,Hoban P,Butson M,Davison A,Metcalfe P

更新日期：2001-05-01 00:00:00

abstract：:Currently, standards for the compliance testing of wireless devices are being extended to cover a wider frequency band and different usage patterns of mobile phones as well as of novel body-worn and handheld devices. As a consequence, not only the head but also strongly varying tissue distributions of the body are exp...

journal_title：Physics in medicine and biology

authors： Christ A,Samaras T,Klingenböck A,Kuster N

更新日期：2006-10-07 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：:The aim of this work was to evaluate the accuracy of dose predicted in heterogeneous media by a pencil beam (PB), a collapsed cone (CC) and a Monte Carlo (MC) algorithm. For this purpose, a simple multi-layer phantom composed of Styrofoam and white polystyrene was irradiated with 10 x 10 cm2 as well as 20 x 20 cm2 ope...

journal_title：Physics in medicine and biology

authors： Krieger T,Sauer OA

更新日期：2005-03-07 00:00:00

abstract：:The medical imaging and therapeutic technologies that are based on the use of radiation are reviewed briefly, with special emphasis on the recent developments of synchrotron radiation (SR) methods. New results have been achieved in all of these areas since the last comprehensive reviews were written in this field. Thi...

journal_title：Physics in medicine and biology

authors： Suortti P,Thomlinson W

更新日期：2003-07-07 00:00:00

abstract：:We introduce a novel x-ray imaging approach that yields information about the local texture of structures smaller than the image pixel resolution inside an object. The approach is based on a recently developed x-ray dark-field imaging technique, using scattering from sub-micron structures in the sample. We show that t...

journal_title：Physics in medicine and biology

authors： Jensen TH,Bech M,Bunk O,Donath T,David C,Feidenhans'l R,Pfeiffer F

更新日期：2010-06-21 00:00:00

abstract：:Two novel materials have been developed to simulate the dielectric properties of human muscle and fat at 1000 MHz. These materials, which are based on ethanediol set with gelatine, are easily made and have good mechanical properties. The complex permittivity, epsilon *, of each material was measured with an open-ended...

journal_title：Physics in medicine and biology

authors： Robinson MP,Richardson MJ,Green JL,Preece AW

更新日期：1991-12-01 00:00:00

abstract：:A 3D anatomical computational model is developed to assess thermal effects due to exposure to the electromagnetic field required to power a new investigational active implantable microvalve for the treatment of glaucoma. Such a device, located in the temporal superior eye quadrant, produces a filtering bleb, which is ...

journal_title：Physics in medicine and biology

authors： Schaumburg F,Guarnieri FA

更新日期：2017-05-07 00:00:00

abstract：:W (the average energy to form an ion pair) for 5.4 MeV 241Am alpha particles in a Rossi-type tissue-equivalent (TE) gas, argon and methane was determined to an accuracy better than 0.2% using a new automated data handling system. A vibrating reed electrometer and current digitiser were used to measure the current prod...

journal_title：Physics in medicine and biology

authors： Krieger GL,Baum JW,Varma MN,Beach JL

更新日期：1979-03-01 00:00:00

abstract：:The purpose of this work is to provide an evaluation of the mean glandular dose (MGD) for breast computed tomography (CT) with synchrotron radiation in an axial scanning configuration with a partial or total organ volume irradiation, for the in vivo program of breast CT ongoing at the ELETTRA facility (Trieste, Italy)...

journal_title：Physics in medicine and biology

authors： Mettivier G,Fedon C,Di Lillo F,Longo R,Sarno A,Tromba G,Russo P

更新日期：2016-01-21 00:00:00

abstract：:Intracoronary thermography is a technique that measures lumen wall temperatures for vulnerable plaque detection. In this paper the influence of vulnerable plaque composition on lumen wall temperatures was studied numerically. Concerning the vulnerable plaque heat generation, the location of the heat source and its hea...

journal_title：Physics in medicine and biology

authors： ten Have AG,Gijsen FJ,Wentzel JJ,Slager CJ,Serruys PW,van der Steen AF

更新日期：2006-11-21 00:00:00

abstract：:Gel dosimetry based on magnetic resonance imaging (MRI) has previously been shown to provide verification of calculated dose distributions in soft tissue equivalent homogeneous phantoms. This study demonstrates how measurements of dose distribution can also be achieved in a phantom containing porous, lung-equivalent, ...

journal_title：Physics in medicine and biology

authors： Olberg S,Skretting A,Bruland O,Olsen DR

更新日期：2000-10-01 00:00:00

abstract：:In order to optimize external-beam conformal radiotherapy, patient movement during treatment must be minimized. For treatment on the upper torso, the target organs are known to move substantially due to patient respiration. This paper deals with the technical aspects of gating the radiotherapy beam synchronously with ...

journal_title：Physics in medicine and biology

authors： Kubo HD,Hill BC

更新日期：1996-01-01 00:00:00

abstract：:The convergence rates of the fast Padé transform (FPT) and the fast Fourier transform (FFT) are compared. These two estimators are used to process a time-signal encoded at 4 T by means of one-dimensional magnetic resonance spectroscopy (MRS) for healthy human brain. It is found systematically that at any level of trun...

journal_title：Physics in medicine and biology

authors： Belkić D,Belkić K

更新日期：2005-09-21 00:00:00

abstract：:The dosimetrical characteristics of a new miniature multileaf collimator (ModuLeaf MLC, MRC Systems GmbH, Heidelberg, Germany) attached to the accessory holder of a Siemens accelerator with 6 MV x-rays (PRIMUS, Siemens OCS, Concord, California, USA) have been investigated. In particular, those parameters which are imp...

journal_title：Physics in medicine and biology

authors： Hartmann GH,Föhlisch F

更新日期：2002-06-21 00:00:00

abstract：:A hydrogen clearance technique for the measurement of capillary blood flow in skeletal muscle (both resting and working) and the beating heart in experimental animals is described. Various methods for introducing the hydrogen into the region of measurement are compared, together with the appropriate methods for evalua...

journal_title：Physics in medicine and biology

authors： Harrison DK,Kessler M

更新日期：1989-10-01 00:00:00

abstract：:Ultrasound shock wave therapy is increasingly used for non-invasive surgery. It requires the focusing of very high pressure amplitude in precisely controlled focal spots. In transcostal therapy of the heart or the liver, the high impedance mismatch between the bones and surrounding tissues gives rise to strong aberrat...

journal_title：Physics in medicine and biology

authors： Robin J,Simon A,Arnal B,Tanter M,Pernot M

更新日期：2018-09-06 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：:The present note addresses the development of a lung tumor position predictor to be used in dynamic tumor tracking radiotherapy, abbreviated as DTT-RT. As there exists 50-500 ms positioning lag in the control of the multi-leaf collimator (MLC) of commercial medical linear accelerators, prediction of future lung tumor ...

journal_title：Physics in medicine and biology

authors： Jiang K,Fujii F,Shiinoki T

更新日期：2019-10-31 00:00:00

abstract：:To monitor and strategically control energy deposition in magnetic resonance imaging (MRI), measured as a specific absorption rate (SAR), numerical methods using generic human models have been employed to estimate worst-case values. Radiofrequency (RF) sequences are therefore often designed conservatively with large s...

journal_title：Physics in medicine and biology

authors： Jin J,Liu F,Weber E,Crozier S

更新日期：2012-12-21 00:00:00

abstract：:We describe an improved algorithm for localising equivalent sources of biomagnetic fields in the human brain. The algorithm is an improvement over the sphere model in that it considers two distinct surfaces: an ellipsoid, to model the region of the skull on which the sensors are placed, and a sphere as the medium in w...

journal_title：Physics in medicine and biology

authors： Pistella F,Barone P,Narici L,Ocello N,Pizzella V,Romani GL

更新日期：1987-01-01 00:00:00

abstract：:Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding techniqu...

journal_title：Physics in medicine and biology

authors： McNally KM,Sorg BS,Welch AJ,Dawes JM,Owen ER

更新日期：1999-04-01 00:00:00

abstract：:Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The...

journal_title：Physics in medicine and biology

authors： Akbarzadeh A,Ay MR,Ghadiri H,Sarkar S,Zaidi H

更新日期：2010-04-21 00:00:00

abstract：:In charged particle therapy with pencil beam scanning (PBS), localization of the dose in the Bragg peak makes dose distributions sensitive to lateral tissue heterogeneities. The sensitivity of a PBS plan to lateral tissue heterogeneities can be reduced by selecting appropriate beam angles. The purpose of this study is...

journal_title：Physics in medicine and biology

authors： Toramatsu C,Inaniwa T

更新日期：2016-12-21 00:00:00

abstract：:We report a new preparative method for providing contrast through reduction in electron density that is uniquely suited for propagation-based differential x-ray phase contrast imaging. The method, which results in an air or fluid filled vasculature, makes possible visualization of the smallest microvessels, roughly do...

journal_title：Physics in medicine and biology

authors： Laperle CM,Hamilton TJ,Wintermeyer P,Walker EJ,Shi D,Anastasio MA,Derdak Z,Wands JR,Diebold G,Rose-Petruck C

更新日期：2008-12-07 00:00:00

abstract：:The measurand relevant for the dosimetry for radiation therapy is the absorbed dose to water, DW. The Physikalisch-Technische Bundesanstalt (PTB) is establishing a secondary standard for DW for high-energy photon and electron radiation based on electron spin resonance (ESR) of the amino acid alanine. For practical app...

journal_title：Physics in medicine and biology

authors： Anton M

更新日期：2008-03-07 00:00:00