Liver-ultrasound based motion modelling to estimate 4D dose distributions for lung tumours in scanned proton therapy.

abstract：:Source anisotropy is a very important factor in the brachytherapy quality assurance of high-dose rate (HDR) 192Ir 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 ...

journal_title：Physics in medicine and biology

authors： Baltas D,Giannouli S,Garbi A,Diakonos F,Geramani K,Ioannidis GT,Tsalpatouros A,Uzunoglu N,Kolotas C,Zamboglou N

更新日期：1998-06-01 00:00:00

abstract：:We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic co...

journal_title：Physics in medicine and biology

authors： Horas JA,Olguin OR,Rizzotto MG

更新日期：2005-04-21 00:00:00

abstract：:Two dosimetry protocols based on absorbed dose to water have recently been implemented: TG-51 and TRS-398. These protocols use different beam-quality indices: %dd(10)x and TPR20,10. The effect of electron contamination in measurements of %dd(10)x has been proposed as a disadvantage of the TG-51. For actual measurement...

journal_title：Physics in medicine and biology

authors： Lopez Medina A,Teijeiro A,Salvador F,Medal D,Vazquez J,Salgado M,Carrion MC

更新日期：2004-01-07 00:00:00

abstract：:Positron range impairs resolution in PET imaging, especially for high-energy emitters and for small-animal PET. De-blurring in image reconstruction is possible if the blurring distribution is known. Furthermore, the percentage of annihilation events within a given distance from the point of positron emission is releva...

journal_title：Physics in medicine and biology

authors： Jødal L,Le Loirec C,Champion C

更新日期：2012-06-21 00:00:00

abstract：:Energy and angular distributions of electron beams with different energies were simulated by Monte Carlo calculations. These beams were generated by the NOVAC7 system (Hitesys, Italy), a mobile electron accelerator specifically dedicated to intra-operative radiation therapy (IORT). The electron beam simulations were v...

journal_title：Physics in medicine and biology

authors： Pimpinella M,Mihailescu D,Guerra AS,Laitano RF

更新日期：2007-10-21 00:00:00

abstract：:Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteri...

journal_title：Physics in medicine and biology

authors： Hoffmann AL,den Hertog D,Siem AY,Kaanders JH,Huizenga H

更新日期：2008-11-21 00:00:00

abstract：:Optical topography is a method for visualization of conical activity. Ways of improving the spatial resolution of the topographical image with three arrangements of optical fibres are discussed. A distribution of sensitivity is obtained from the phantom experiment, and used to reconstruct topographical images of an ac...

journal_title：Physics in medicine and biology

authors： Yamamoto T,Maki A,Kadoya T,Tanikawa Y,Yamad Y,Okada E,Koizumi H

更新日期：2002-09-21 00:00:00

abstract：:Large blood vessels can produce steep temperature gradients in heated tissues leading to inadequate tissue temperatures during hyperthermia. This paper utilizes a finite difference scheme to solve the basic equations of heat transfer and fluid flow to model blood vessel cooling. Unlike previous formulations, heat tran...

journal_title：Physics in medicine and biology

authors： Kolios MC,Sherar MD,Hunt JW

更新日期：1995-04-01 00:00:00

abstract：:The goal of this study is to demonstrate the feasibility of a novel non-coplanar-arc optimization algorithm (CyberArc). This method aims to reduce the delivery time of conventional CyberKnife treatments by allowing for continuous beam delivery. CyberArc uses a 4 step optimization strategy, in which nodes, beams, and c...

journal_title：Physics in medicine and biology

authors： Kearney V,Cheung JP,McGuinness C,Solberg TD

更新日期：2017-06-26 00:00:00

abstract：:The basic principles of x-ray image formation in radiology have remained essentially unchanged since Röntgen first discovered x-rays over a hundred years ago. The conventional approach relies on x-ray attenuation as the sole source of contrast and draws exclusively on ray or geometrical optics to describe and interpre...

journal_title：Physics in medicine and biology

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

更新日期：2010-09-21 00:00:00

abstract：:Monte Carlo (MC) simulations are often at the heart of the testing procedure in biomedical optics. One of the critical points in MC simulations is to define the new photon direction after each scattering event. One of the most popular solutions is to use the Henyey-Greenstein phase function or some linear combinations...

journal_title：Physics in medicine and biology

authors： Binzoni T,Leung TS,Gandjbakhche AH,Rüfenacht D,Delpy DT

更新日期：2006-09-07 00:00:00

abstract：:Intensive computation time is required to simulate images of electronic portal imaging device (EPID) using Monte Carlo (MC) technique, limiting the development of applications associated with EPID, such as mega-voltage cone-beam computed tomography (MV-CBCT). In this study, a fast, accurate simulation strategy for MV-...

journal_title：Physics in medicine and biology

authors： Shi M,Myronakis M,Jacobson M,Lehmann M,Ferguson D,Baturin P,Huber P,Fueglistaller R,Harris T,Lozano IV,Williams C,Morf D,Berbeco RI

更新日期：2020-07-06 00:00:00

abstract：:We evaluated the basic properties of a commercially available BANGkit gel dosimeter, which is a normoxic type of BANG gel. This gel-kit has the same composition as the BANG 3 gel, but is fully oxygenated. To exclude oxygen, oxygen scavenging ascorbic acid and copper sulfate as a catalyst are used. The properties that ...

journal_title：Physics in medicine and biology

authors： Murakami Y,Nakashima T,Watanabe Y,Akimitsu T,Matsuura K,Kenjo M,Kaneyasu Y,Wadasaki K,Hirokawa Y,Ito K

更新日期：2007-04-21 00:00:00

abstract：:In the field of regenerative medicine, there has been a growing interest in studying the combination of bone scaffolds and cells that can maximize newly formed bone. In-line phase-contrast x-ray tomography was used to image porous bone scaffolds (Skelite(©)), seeded with bone forming cells. This technique allows the q...

journal_title：Physics in medicine and biology

authors： Weber L,Langer M,Tavella S,Ruggiu A,Peyrin F

更新日期：2016-05-07 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：:Therapy with helium ions is currently receiving significantly increasing interest because helium ions have a sharper penumbra than protons and undergo less fragmentation than carbon ions and thus require less complicated dose calculations. For any ion of interest in hadron therapy, the accuracy of dose delivery is lim...

journal_title：Physics in medicine and biology

authors： Ozoemelam I,van der Graaf E,Brandenburg S,Dendooven P

更新日期：2019-12-05 00:00:00

abstract：:Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitive image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE)...

journal_title：Physics in medicine and biology

authors： Padgett R,Kotre CJ

更新日期：2004-03-21 00:00:00

abstract：:To achieve accurate and fast deformable image registration (DIR) for pulmonary CT, we proposed a Multi-scale DIR framework with unsupervised Joint training of Convolutional Neural Network (MJ-CNN). MJ-CNN contains three models at multi-scale levels for a coarse-to-fine DIR to avoid being trapped in a local minimum. It...

journal_title：Physics in medicine and biology

authors： Jiang Z,Yin FF,Ge Y,Ren L

更新日期：2020-01-13 00:00:00

abstract：:Rheumatoid arthritis is one of the most common epidemic diseases in the world. For some patients, the treatment with steroids or nonsteroidal anti-inflammatory drugs is not effective, thus necessitating physical removal of the inflamed synovium. Alternative approaches other than surgery will provide appropriate diseas...

journal_title：Physics in medicine and biology

authors： Wu J,Chang SJ,Chuang KS,Hsueh YW,Yeh KC,Wang JN,Tsai WP

更新日期：2007-03-21 00:00:00

abstract：:The phosphor GdO2S:Tb is widely used in camera-based electronic portal imaging devices (EPIDs). There is considerable interest in the application of EPIDs to dosimetry and the verification of intensity modulated radiation therapy produced by dynamic multileaf collimation (DMLC). This paper presents direct measurement ...

journal_title：Physics in medicine and biology

authors： Glendinning AG,Hunt SG,Bonnett DE

更新日期：2001-02-01 00:00:00

abstract：:Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image ...

journal_title：Physics in medicine and biology

authors： Schwemmer C,Rohkohl C,Lauritsch G,Müller K,Hornegger J

更新日期：2013-06-07 00:00:00

abstract：:Periacetabular osteotomy (PAO) is a joint preservation procedure for developmental dysplasia of the hip. Such a procedure requires osteotomy of the medial wall of the acetabulum, which may cause the narrow of the bony birth canal and increase the risk of complications during the childbirth process in the future. Using...

journal_title：Physics in medicine and biology

authors： Shao L,Li H,Liu X,Wang Y,Shi L,Ai D,Fan J,Song H,Zhang H,Yang J

更新日期：2021-01-22 00:00:00

abstract：:Shear wave elastography (SWE) is a potential tool to non-invasively assess cardiac muscle stiffness. This study focused on the effect of the orthotropic material properties and mechanical loading on the performance of cardiac SWE, as it is known that these factors contribute to complex 3D anisotropic shear wave propag...

journal_title：Physics in medicine and biology

authors： Caenen A,Pernot M,Peirlinck M,Mertens L,Swillens A,Segers P

更新日期：2018-03-23 00:00:00

abstract：:Recently, the Task Group 103 of the International Commission on Radiological Protection (ICRP) has developed new mesh-type reference computational phantoms (MRCPs) for adult male and female. When compared to the current voxel-type reference computational phantoms in ICRP Publication 110, the MRCPs have several advanta...

journal_title：Physics in medicine and biology

authors： Lee H,Yeom YS,Nguyen TT,Choi C,Han H,Shin B,Zhang X,Kim CH,Chung BS,Zankl M

更新日期：2019-02-05 00:00:00

abstract：:Beam tracking with scanned carbon ion radiotherapy achieves highly conformal target dose by steering carbon pencil beams to follow moving tumors using real-time magnetic deflection and range modulation. The purpose of this study was to evaluate the robustness of target dose coverage from beam tracking in light of posi...

journal_title：Physics in medicine and biology

authors： Eley JG,Newhauser WD,Richter D,Lüchtenborg R,Saito N,Bert C

更新日期：2015-02-21 00:00:00

abstract：:This paper describes an accurate and time-efficient method for the determination of total body potassium via a combination of measurements in the Birmingham whole body counter and the use of the Monte Carlo n-particle (MCNP) simulation code. In developing this method, MCNP has also been used to derive values for some ...

journal_title：Physics in medicine and biology

authors： O'Hehir S,Green S,Beddoe AH

更新日期：2006-09-07 00:00:00

abstract：:A method using both patient geometric and dosimetric information was proposed to predict dose-volume histograms (DVHs) of organs at risk (OARs) for a nasopharyngeal cancer (NPC) intensity-modulated radiation therapy (IMRT) plan. A total of 106 nine-field IMRT NPC plans were used in this study. Twenty-six plans were ra...

journal_title：Physics in medicine and biology

authors： Jiao SX,Chen LX,Zhu JH,Wang ML,Liu XW

更新日期：2019-12-05 00:00:00

abstract：:The purpose of this study was the evaluation of the impact of a variable relative biological effectiveness (RBE) compared to a constant RBE value of 1.1 in proton therapy prostate trials due to uncertainties in α/β ratio. Twenty patients receiving passive scattered proton therapy (PSPT) and fifteen patients receiving ...

journal_title：Physics in medicine and biology

authors： Marteinsdottir M,Paganetti H

更新日期：2019-06-05 00:00:00

abstract：:Evidence that some lung tumors change shape during respiration is derived from respiratory gated CT data by statistical shape modeling and image manipulation. Some tumors behave as rigid objects while others show systematic shape changes. Two views of lung motion are presented to allow analysis of the results. In the ...

journal_title：Physics in medicine and biology

authors： Kyriakou E,McKenzie DR

更新日期：2012-02-21 00:00:00

abstract：:The aim of the study is to determine PTV margin for inter-observer variability in the volumetric modulated arc therapy (VMAT) prostate radiotherapy with high-dose volumetric CT (HDVCT) and conventional helical CT (CCT) for planning. Secondly to investigate the impact of geometric (PTV expansion) and dosimetric (confor...

journal_title：Physics in medicine and biology

authors： Cho YB,Alasti H,Kong V,Catton C,Berlin A,Chung P,Bayley A,Jaffray D

更新日期：2019-03-14 00:00:00