Commissioning of pencil beam and Monte Carlo dose engines for non-isocentric treatments in scanned proton beam therapy.

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：:This is a proof of principle study on an algorithm for optimizing external beam radiotherapy in terms of both photon beamlet energy and fluence. This simultaneous beamlet energy and fluence optimization is denoted modulated photon radiotherapy (XMRT). XMRT is compared with single-energy intensity modulated radiotherap...

journal_title：Physics in medicine and biology

authors： McGeachy P,Villarreal-Barajas JE,Zinchenko Y,Khan R

更新日期：2016-02-21 00:00:00

abstract：:As the use of radiofrequency (RF) electromagnetic (EM) fields has increased along with increased use of wireless communication, the possible related health risks have also been widely discussed. One safety aspect is the interaction of medical implants and RF devices like mobile phones. In the literature, effects on ac...

journal_title：Physics in medicine and biology

authors： Virtanen H,Keshvari J,Lappalainen R

更新日期：2007-03-07 00:00:00

abstract：:In this work we present the first delivery of intensity modulated arc therapy on the Elekta Unity 1.5 T MR-linac. The machine's current IMRT based control system was modified suitably to enable dynamic delivery of radiation, for the purpose of exploring MRI-guided radiation therapy adaptation modes in a research setti...

journal_title：Physics in medicine and biology

authors： Kontaxis C,Woodhead PL,Bol GH,Lagendijk JJW,Raaymakers BW

更新日期：2020-12-23 00:00:00

abstract：:Infrared measurements have been used to profile or image biological tissue, including human skin. Usually, analysis of such measurements has assumed that infrared absorption is due to water and collagen. Such an assumption may be reasonable for soft tissue, but introduction of exogenous agents into skin or the measure...

journal_title：Physics in medicine and biology

authors： Viator JA,Choi B,Peavy GM,Kimel S,Nelson JS

更新日期：2003-01-21 00:00:00

abstract：:It has been demonstrated that gas-filled microbubble contrast agents, based on their volume changes, can serve as pressure probes in an MR field. It was recently reported that such an MR-based pressure measurement with microbubbles at 1.5 T must make use of microbubbles that have a volumetric magnetic susceptibility d...

journal_title：Physics in medicine and biology

authors： Dharmakumar R,Plewes DB,Wright GA

更新日期：2005-10-21 00:00:00

abstract：:The use of deformable image registration methods in the context of adaptive radiotherapy leads to uncertainties in the simulation of the administered dose distributions during the treatment course. Evaluation of these methods is a prerequisite to decide if a plan adaptation will improve the individual treatment. Curre...

journal_title：Physics in medicine and biology

authors： Teske H,Bartelheimer K,Meis J,Bendl R,Stoiber EM,Giske K

更新日期：2017-06-21 00:00:00

abstract：:The concepts of radiance and fluence are fundamental to the description of a radiation field. The International Commission on Radiological Units and Measurements (ICRU) has defined fluence in terms of the number of the radiation particles crossing a small sampling sphere. A second definition has been proposed in which...

journal_title：Physics in medicine and biology

authors： Papiez L,Battista JJ

更新日期：1994-06-01 00:00:00

abstract：:We find the dose distribution that maximizes the tumour control probability (TCP) for a fixed mean tumour dose per fraction. We consider a heterogeneous tumour volume having a radiation response characterized by the linear quadratic model with heterogeneous radiosensitivity and repopulation rate that may vary in time....

journal_title：Physics in medicine and biology

authors： Levin-Plotnik D,Hamilton RJ

更新日期：2004-02-07 00:00:00

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：:The aim of this study is to investigate the use of mathematical morphology for the determination of left ventricular contours in scintigraphic images using multigated radionuclide angiography. We have developed a completely automatic method that first restores the image with a Wiener filter, then finds the region wher...

journal_title：Physics in medicine and biology

authors： Pladellorens J,Serrat J,Castell A,Yzuel MJ

更新日期：1993-12-01 00:00:00

abstract：:Changes in the relative biological effectiveness (RBE) of the radiation-induced cell killing of human salivary glands (HSG) were assessed along the Bragg peak of a 60 MeV clinical proton beam by means of coupling biophysical models with the results of Monte Carlo radiation transport simulations and experimental measur...

journal_title：Physics in medicine and biology

authors： Parisi A,Olko P,Swakoń J,Horwacik T,Jabłoński H,Malinowski L,Nowak T,Struelens L,Vanhavere F

更新日期：2020-01-10 00:00:00

abstract：:The 0.35 T 60Co MRIdian system (ViewRay Inc., Mountain View) has been in clinical use in our institution since May 2016. For quality assurance (QA) of dose delivery and end-to-end testing for this machine, a reliable dosimeter is required. However, it is possible that a magnetic field may cause perturbations to dosime...

journal_title：Physics in medicine and biology

authors： Barten DLJ,Hoffmans D,Palacios MA,Heukelom S,van Battum LJ

更新日期：2018-08-20 00:00:00

abstract：:In this paper, we present a segmentation and classification method for thyroid follicular neoplasms based on a combination of the prior-based level set method and deep convolutional neural network. The proposed method aims to discriminate thyroid follicular adenoma (TFA) and follicular thyroid carcinoma (FTC) in ultra...

journal_title：Physics in medicine and biology

authors： Yang B,Yan M,Yan Z,Zhu C,Xu D,Dong F

更新日期：2020-11-02 00:00:00

abstract：:This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR (192)Ir brachytherapy sources. I...

journal_title：Physics in medicine and biology

authors： Bidmead AM,Sander T,Locks SM,Lee CD,Aird EG,Nutbrown RF,Flynn A,IPEM Working Party.

更新日期：2010-06-07 00:00:00

abstract：:Fixed-pattern noise in electronic portal images (EPIs) is normally eliminated by dividing raw image data by an open-field calibration image (OFCI). However, for successful elimination, there must be exact registration between the two image sets. Any movement within the imaging system, such as that which occurs with ga...

journal_title：Physics in medicine and biology

authors： Kirby MC

更新日期：1996-11-01 00:00:00

abstract：:Spreadsheet templates which calculate cumulative exposures to other persons from patients to whom radioactive materials have been administered have been developed by the authors. Calculations can be based on any specified single-, bi- or tri-exponential whole-body clearance rate and a diurnal (or any other periodic) c...

journal_title：Physics in medicine and biology

authors： Cormack J,Shearer J

更新日期：1998-03-01 00:00:00

abstract：:Computer aided detection (CADe) for breast lesion can provide an important reference for radiologists in breast cancer screening. Architectural distortion (AD) is a type of breast lesion that is difficult to detect. A majority of CADe methods focus on detecting the radial pattern, which is a main characteristic of typ...

journal_title：Physics in medicine and biology

authors： Li Y,He Z,Lu Y,Ma X,Guo Y,Xie Z,Xu Z,Chen W,Chen H

更新日期：2020-06-02 00:00:00

abstract：:A software program, SpekCalc, is presented for the calculation of x-ray spectra from tungsten anode x-ray tubes. SpekCalc was designed primarily for use in a medical physics context, for both research and education purposes, but may also be of interest to those working with x-ray tubes in industry. Noteworthy is the p...

journal_title：Physics in medicine and biology

authors： Poludniowski G,Landry G,DeBlois F,Evans PM,Verhaegen F

更新日期：2009-10-07 00:00:00

abstract：:The artificial urinary sphincter should be long enough to prevent strangulation effects of the urethral tissue and short enough to avoid the improper dissection of the surrounding tissue. To optimize the sphincter length, the empirical three-parameter urethra compression model is proposed based on the mechanical prope...

journal_title：Physics in medicine and biology

authors： Marti F,Leippold T,John H,Blunschi N,Müller B

更新日期：2006-03-07 00:00:00

abstract：:Acidic drinks and foodstuffs can demineralize dental hard tissues, leading to a pathological condition known as dental erosion, which is of increasing clinical concern. The first step in enamel dissolution is a demineralization of the outer few micrometres of tissue, which results in a softening of the structure. The ...

journal_title：Physics in medicine and biology

authors： Barbour ME,Shellis RP

更新日期：2007-02-21 00:00:00

abstract：:Inverse treatment planning in intensity modulated particle therapy (IMPT) with scanned carbon-ion beams is currently based on the optimization of RBE-weighted dose to satisfy requirements of target coverage and limited toxicity to organs-at-risk (OARs) and healthy tissues. There are many feasible IMPT plans that meet ...

journal_title：Physics in medicine and biology

authors： Burigo LN,Ramos-Méndez J,Bangert M,Schulte RW,Faddegon B

更新日期：2019-01-04 00:00:00

abstract：:An open-ended coaxial probe is often used for investigating the dielectric properties of biological tissues. The present study indicates that in addition to the probe size, the penetration of the electromagnetic (EM) fields of an open-ended coaxial probe in contact with the skin is dependent on the applied frequency b...

journal_title：Physics in medicine and biology

authors： Alanen E,Lahtinen T,Nuutinen J

更新日期：1999-07-01 00:00:00

abstract：:Partial volume effects (PVEs) are consequences of the limited spatial resolution in emission tomography. They lead to a loss of signal in tissues of size similar to the point spread function and induce activity spillover between regions. Although PVE can be corrected for by using algorithms that provide the correct ra...

journal_title：Physics in medicine and biology

authors： Boussion N,Hatt M,Lamare F,Bizais Y,Turzo A,Cheze-Le Rest C,Visvikis D

更新日期：2006-04-07 00:00:00

abstract：:Calculating the dynamic properties of magnetization of single-domain particles is of great importance for the tomographic imaging modality known as magnetic particle imaging (MPI). Although the assumption of instantaneous thermodynamic equilibrium (Langevin function) after application of time-dependent magnetic fields...

journal_title：Physics in medicine and biology

authors： Weizenecker J

更新日期：2018-01-22 00:00:00

abstract：:Measurement of the dielectric properties of ocular tissues up to 110 GHz was performed by the coaxial probe method. A coaxial sensor was fabricated to allow the measurement of small amounts of biological tissues. Four-standard calibration was applied in the dielectric property measurement to obtain more accurate data ...

journal_title：Physics in medicine and biology

authors： Sasaki K,Isimura Y,Fujii K,Wake K,Watanabe S,Kojima M,Suga R,Hashimoto O

更新日期：2015-08-21 00:00:00

abstract：:The layer-stacking method can provide three-dimensional conformal dose distributions to the target based on a passive scattering method using mini-spread-out Bragg peak (SOBP). The purpose of this work is to demonstrate the effectiveness of a new weight optimization algorithm that can enhance the robustness of dose di...

journal_title：Physics in medicine and biology

authors： Sakamoto Y,Maeda Y,Yamada Y,Ikeda M,Tameshige Y,Sasaki M,Shibata S,Yamamoto K

更新日期：2020-09-28 00:00:00

abstract：:We show that it is possible to translate an intensity modulated radiation therapy (IMRT) treatment plan and deliver it as a single arc. This technique is referred to in this paper as aperture modulation arc therapy (AMAT). During this arc, the MLC leaves do not conform to the projection of the target PTV and the machi...

journal_title：Physics in medicine and biology

authors： Crooks SM,Wu X,Takita C,Watzich M,Xing L

更新日期：2003-05-21 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：:Determining a multidimensional velocity field within microscale opaque fluid flows is needed in areas such as microfluidic devices, biofluid mechanics and hemodynamics research in animal studies. The ultrasonic particle image velocimetry (EchoPIV) technique is appropriate for measuring opaque flows by taking advantage...

journal_title：Physics in medicine and biology

authors： Qian M,Niu L,Wang Y,Jiang B,Jin Q,Jiang C,Zheng H

更新日期：2010-10-21 00:00:00