Transport calculations of depth-dose distributions for gadolinium neutron capture therapy.

abstract：:A pencil beam model for the calculation of the lateral scattering in water of protons for any therapeutic energy and depth is presented. It is based on the full Molière theory, taking into account the energy loss and the effects of mixtures and compounds. Concerning the electromagnetic part, the model has no free para...

journal_title：Physics in medicine and biology

authors： Bellinzona EV,Ciocca M,Embriaco A,Ferrari A,Fontana A,Mairani A,Parodi K,Rotondi A,Sala P,Tessonnier T

更新日期：2016-02-21 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：:In this study we investigate light penetration into skin in order to define the optimal wavelength for the treatment of port wine stains. A two-layer model (epidermis and dermis) is applied with a cylindric tube representing the ectatic blood vessel. Light propagation is calculated by the Monte Carlo method. Values fo...

journal_title：Physics in medicine and biology

authors： Kienle A,Hibst R

更新日期：1995-10-01 00:00:00

abstract：:The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, ...

journal_title：Physics in medicine and biology

authors： Pepin EW,Wu H,Sandison GA,Langer M,Shirato H

更新日期：2010-06-21 00:00:00

abstract：:In dynamic renal scintigraphy, the main interest is the radiopharmaceutical redistribution as a function of time. Quality control (QC) of renal procedures often relies on phantom experiments to compare image-based results with the measurement setup. A phantom with a realistic anatomy and time-varying activity distribu...

journal_title：Physics in medicine and biology

authors： Brolin G,Gleisner KS,Ljungberg M

更新日期：2013-05-21 00:00:00

abstract：:The S-value is a standard measure in cellular dosimetry. S-values are calculated by applying analytical methods or by Monte Carlo simulation. In Monte Carlo simulation, particles are either tracked individually event-by-event or close events are condensed and processed collectively in different steps. Both of these me...

journal_title：Physics in medicine and biology

authors： Tajik-Mansoury MA,Rajabi H,Mozdarani H

更新日期：2017-03-07 00:00:00

abstract：:For medical applications of ultrasound inside the brain, it is necessary to understand the relationship between the apparent density of skull bone and its corresponding speed of sound and attenuation coefficient. Although there have been previous studies exploring this phenomenon, there is still a need to extend the m...

journal_title：Physics in medicine and biology

authors： Pichardo S,Sin VW,Hynynen K

更新日期：2011-01-07 00:00:00

abstract：:A single experimental apparatus has been designed to allow measurements of stopping cross-sections of materials in liquid and vapour phase, for alpha particles, using an indirect method. The method, in which residual energies for increasing absorber thicknesses are obtained and differentiated, has been used in a numbe...

journal_title：Physics in medicine and biology

authors： Thwaites DI

更新日期：1980-09-01 00:00:00

abstract：:Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbea...

journal_title：Physics in medicine and biology

authors： Correia M,Maresca D,Goudot G,Villemain O,Bizé A,Sambin L,Tanter M,Ghaleh B,Pernot M

更新日期：2020-06-05 00:00:00

abstract：:Radiation therapy is an image-guided process whose success critically depends on the imaging modality used for treatment planning and the level of integration of the available imaging information. In this work, we establish a dose optimization framework for incorporating metabolic information from functional imaging m...

journal_title：Physics in medicine and biology

authors： Xing L,Cotrutz C,Hunjan S,Boyer AL,Adalsteinsson E,Spielman D

更新日期：2002-10-21 00:00:00

abstract：:Many models exist for predicting toxicities based on dose-volume histograms (DVHs) or dose-surface histograms (DSHs). This approach has several drawbacks as firstly the reduction of the dose distribution to a histogram results in the loss of spatial information and secondly the bins of the histograms are highly correl...

journal_title：Physics in medicine and biology

authors： Buettner F,Gulliford SL,Webb S,Partridge M

更新日期：2011-04-07 00:00:00

abstract：:We study threshold-driven optimization methodology for automatically generating a treatment plan that is motivated by a reference DVH for IMRT treatment planning. We present a framework for threshold-driven optimization for reference-based auto-planning (TORA). Commonly used voxel-based quadratic penalties have two co...

journal_title：Physics in medicine and biology

authors： Long T,Chen M,Jiang S,Lu W

更新日期：2018-02-08 00:00:00

abstract：:In this paper we present a novel method of reducing the dosimetric effects of the finite leaf width of a multileaf collimator (MLC) in conformal and intensity modulated radiotherapy (IMRT). This is achieved by decomposing the required high-resolution fluence distribution into two orthogonal components, which are deliv...

journal_title：Physics in medicine and biology

authors： Evans PM,Partridge M

更新日期：2000-03-01 00:00:00

abstract：:A method is presented for extraction of intra and inter fraction motion of seeds/markers within the patient from cone beam CT (CBCT) projection images. The position of the marker is determined on each projection image and fitted to a function describing the projection of a fixed point onto the imaging panel at differe...

journal_title：Physics in medicine and biology

authors： Marchant TE,Amer AM,Moore CJ

更新日期：2008-02-21 00:00:00

abstract：:In this work, we propose a framework for optimizing spectral CT imaging parameters and hardware design with regard to material classification tasks. Compared with conventional CT, many more parameters must be considered when designing spectral CT systems and protocols. These choices will impact material classification...

journal_title：Physics in medicine and biology

authors： Rigie DS,La Rivière PJ

更新日期：2016-06-21 00:00:00

abstract：:In nonlinear optimisation, using exact Hessian computations (full-Newton) hold superior convergence properties over quasi-Newton methods or gradient-based methods. However, for medium-scale problems, computing the Hessian can be computationally expensive and thus time-consuming. For solvers dedicated to a specific pro...

journal_title：Physics in medicine and biology

authors： van Haveren R,Breedveld S

更新日期：2019-08-14 00:00:00

abstract：:Several applications in nuclear medicine require absolute activity quantification of single photon emission computed tomography images. Obtaining a repeatable calibration factor that converts voxel values to activity units is essential for these applications. Because source preparation and measurement of the source ac...

journal_title：Physics in medicine and biology

authors： Anizan N,Wang H,Zhou XC,Wahl RL,Frey EC

更新日期：2015-02-07 00:00:00

abstract：:The degradation of low energy electrons in a methane based, tissue equivalent gas was studied experimentally by ionization chamber experiments and theoretically by Monte Carlo electron transport simulation in the energy range between 25 eV and 5 keV. From measured ionization yields and calculated ionization and energy...

journal_title：Physics in medicine and biology

authors： Waibel E,Grosswendt B

更新日期：1992-05-01 00:00:00

abstract：:A recent paper proposed a novel technique for determining the total body water (TBW) of patients suffering with abnormal hydration levels, using a resonant cavity perturbation method. Current techniques to measure TBW are limited by resolution and technical constraints. However, this new method involves measuring the ...

journal_title：Physics in medicine and biology

authors： Stone DA,Robinson MP

更新日期：2004-05-07 00:00:00

abstract：:The aim of this study was to evaluate angiogenic compositions and tumour response in the course of neoadjuvant chemotherapy in patients with locally advanced breast cancer (LABC) using dynamic contrast-enhanced (DCE) MRI. Thirteen patients with LABC underwent serial DCE MRI during the course of chemotherapy. DCE MRI w...

journal_title：Physics in medicine and biology

authors： Chang YC,Huang CS,Liu YJ,Chen JH,Lu YS,Tseng WY

更新日期：2004-08-21 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 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：:A comprehensive set of measurements and calculations has been conducted to investigate the accuracy of the Dose Planning Method (DPM) Monte Carlo code for electron beam dose calculations in heterogeneous media. Measurements were made using 10 MeV and 50 MeV minimally scattered, uncollimated electron beams from a racet...

journal_title：Physics in medicine and biology

authors： Chetty IJ,Moran JM,Nurushev TS,McShan DL,Fraass BA,Wilderman SJ,Bielajew AF

更新日期：2002-06-07 00:00:00

abstract：:Mean glandular dose is the quantity used for dosimetry in mammography and depends on breast-related characteristics, such as thickness and density, and on the x-ray spectrum used for breast imaging. This work aims to present an experimentally-based method to derive polyenergetic normalized glandular dose coefficients ...

journal_title：Physics in medicine and biology

authors： Santos JC,Tomal A,de Barros N,Costa PR

更新日期：2019-05-10 00:00:00

abstract：:This study looks at blood flow in four different human right coronary arteries (RCAs), which have been reconstructed from bi-plane angiograms. A generalized power-law model of blood viscosity is used to study the blood flow at a particular point in the cardiac cycle. Large differences are found in the wall shear stres...

journal_title：Physics in medicine and biology

authors： Johnston BM,Johnston PR

更新日期：2007-05-07 00:00:00

abstract：:Online adaptive radiation therapy (ART) based on real-time magnetic resonance imaging represents a paradigm-changing treatment scheme. However, conventional quality assurance (QA) methods based on phantom measurements are not feasible with the patient on the treatment couch. The purpose of this work is to develop a fa...

journal_title：Physics in medicine and biology

authors： Wang Y,Mazur TR,Park JC,Yang D,Mutic S,Li HH

更新日期：2017-06-21 00:00:00

abstract：:The standard Fourier metrics used for assessing image quality in computed tomography (CT) use a planar (2D) formulation of the noise equivalent quanta (NEQ) without a specific concept to manage the influence of longitudinal resolution variations, thus create a bias in the comparison of image quality for different reco...

journal_title：Physics in medicine and biology

authors： Monnin P,Viry A,Verdun FR,Racine D

更新日期：2020-06-09 00:00:00

abstract：:Many applications of electroporation, especially those utilizing electrofusion and in-vivo electroporation, involve cell environments that include close cell-to-cell proximity and a wide range of target cell size. It is important to understand how this kind of environment may alter optimum electroporation electrical p...

journal_title：Physics in medicine and biology

authors： Gaynor PT,Bodger PS

更新日期：2006-06-21 00:00:00

abstract：:An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two d...

journal_title：Physics in medicine and biology

authors： Lehnert W,Meikle SR,Siegel S,Newport D,Banati RB,Rosenfeld AB

更新日期：2006-08-21 00:00:00

abstract：:The transverse magnetic field of an MRI-linac sweeps contaminant electrons away from the radiation beam. Films oriented perpendicular to the magnetic field and 5 cm from the radiation beam edge show a projection of the divergent beam, indicating that contaminant electrons spiral along magnetic field lines and deposit ...

journal_title：Physics in medicine and biology

authors： Hackett SL,van Asselen B,Wolthaus JWH,Bluemink JJ,Ishakoglu K,Kok J,Lagendijk JJW,Raaymakers BW

更新日期：2018-05-01 00:00:00