Pre-optimization of radiotherapy treatment planning: an artificial neural network classification aided technique.

abstract：:Radiation dose calculation using models of the human anatomy has been a subject of great interest to radiation protection, medical imaging, and radiotherapy. However, early pioneers of this field did not foresee the exponential growth of research activity as observed today. This review article walks the reader through...

journal_title：Physics in medicine and biology

authors： Xu XG

更新日期：2014-09-21 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：:In response to the recognized fragility of reactor-produced (99)Mo supply, direct production of (99m)Tc via (100)Mo(p,2n)(99m)Tc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with (99m)Tc, other technetium (Tc) radioa...

journal_title：Physics in medicine and biology

authors： Hou X,Tanguay J,Buckley K,Schaffer P,Bénard F,Ruth TJ,Celler A

更新日期：2016-01-21 00:00:00

abstract：:Conventional molecular assessment of tissue through histology, if adapted to fresh thicker samples, has the potential to enhance cancer detection in surgical margins and monitoring of 3D cell culture molecular environments. However, in thicker samples, substantial background staining is common despite repeated rinsing...

journal_title：Physics in medicine and biology

authors： Xu X,Wang Y,Xiang J,Liu JTC,Tichauer KM

更新日期：2017-06-21 00:00:00

abstract：:The ion recombination is examined in parallel-plate ionization chambers in scanning proton beams at the Danish Centre for Particle Therapy and the Skandion Clinic. The recombination correction factor k s is investigated for clinically relevant energies between 70 MeV and 244 MeV for dose rates below 400 Gy min-1 in ai...

journal_title：Physics in medicine and biology

authors： Christensen JB,Almhagen E,Stolarczyk L,Liszka M,Hernandez GG,Bassler N,Nørrevang O,Vestergaard A

更新日期：2020-06-05 00:00:00

abstract：:To address the quality assurance (QA) of a MR-linac which is an MRI combined with a linear accelerator (linac), the traditional linac QA-tests need to be redesigned, since the presence of the static magnetic field in the MR-linac alters the electron trajectory. The latter causes the asymmetry in the dose kernel which ...

journal_title：Physics in medicine and biology

authors： van Zijp HM,van Asselen B,Wolthaus JW,Kok JM,de Vries JH,Ishakoglu K,Beld E,Lagendijk JJ,Raaymakers BW

更新日期：2016-02-07 00:00:00

abstract：:Diffuse optical tomography is an imaging technique whereby spatial maps of absorption and scattering coefficients are derived from the characteristics of multiply scattered light transmitted through the object. The system described here used four intensity-modulated light sources and measurements of the intensity and ...

journal_title：Physics in medicine and biology

authors： Pogue BW,Patterson MS,Jiang H,Paulsen KD

更新日期：1995-10-01 00:00:00

abstract：:Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contras...

journal_title：Physics in medicine and biology

authors： Tsai CH,Zhang JW,Liao YY,Liu HL

更新日期：2016-04-07 00:00:00

abstract：:Recently, there has been an increased interest in imaging different pulmonary disorders using PET techniques. Previous work has shown, for static PET/CT, that air content in the lung influences reconstructed image values and that it is vital to correct for this 'tissue fraction effect' (TFE). In this paper, we extend ...

journal_title：Physics in medicine and biology

authors： Holman BF,Cuplov V,Millner L,Hutton BF,Maher TM,Groves AM,Thielemans K

更新日期：2015-09-21 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：:Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse t...

journal_title：Physics in medicine and biology

authors： Simicevic N

更新日期：2005-11-07 00:00:00

abstract：:This study evaluates the performance of the Bruker positron emission tomograph (PET) insert combined with a BioSpec 70/30 USR magnetic resonance imaging (MRI) scanner using the manufacturer acceptance protocol and the NEMA NU 4-2008 for small animal PET. The PET insert is made of 3 rings of 8 monolithic LYSO crystals ...

journal_title：Physics in medicine and biology

authors： Gsell W,Molinos C,Correcher C,Belderbos S,Wouters J,Junge S,Heidenreich M,Vande Velde G,Rezaei A,Nuyts J,Cawthorne C,Cleeren F,Nannan L,Deroose CM,Himmelreich U,González Martínez AJ

更新日期：2020-06-26 00:00:00

abstract：:Ion chamber dosimetry requires a high degree of precision, at all steps within the dosimetric process, in order to ensure accurate dose measurements. This work presents a novel technique for ion chamber volume determination and quality assurance, using micro-computed tomography (micro-CT). Four nominally identical Exr...

journal_title：Physics in medicine and biology

authors： McNiven AL,Umoh J,Kron T,Holdsworth DW,Battista JJ

更新日期：2008-09-21 00:00:00

abstract：:The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose us...

journal_title：Physics in medicine and biology

authors： Cai W,Dhou S,Cifter F,Myronakis M,Hurwitz MH,Williams CL,Berbeco RI,Seco J,Lewis JH

更新日期：2016-01-21 00:00:00

abstract：:Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR an...

journal_title：Physics in medicine and biology

authors： Chang T,Chang G,Kohlmyer S,Clark JW,Rohren E,Mawlawi OR

更新日期：2011-08-21 00:00:00

abstract：:In radiation therapy, a plan is robust if the calculated and the delivered dose are in agreement, even in the case of different uncertainties. The current practice is to use safety margins, expanding the clinical target volume sufficiently enough to account for treatment uncertainties. This, however, might not be idea...

journal_title：Physics in medicine and biology

authors： Albertini F,Hug EB,Lomax AJ

更新日期：2011-07-21 00:00:00

abstract：:Stereotactic Gamma Knife radiosurgery utilizes ionizing beams from (60)Co sources and relies on a combination of collimator sizes, weighting, etc to generate a high-dose region that is conformal with a designated target volume. Dose computation is typically performed by computer, but in this paper, single collimator d...

journal_title：Physics in medicine and biology

authors： Fenner J,Gwilliam M,Mehrem R,Bird A,Walton L

更新日期：2008-04-21 00:00:00

abstract：:This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen diff...

journal_title：Physics in medicine and biology

authors： Tada S

更新日期：2010-07-21 00:00:00

abstract：:Managing uncertainty is a major challenge in radiation therapy treatment planning, including uncertainty induced by intrafraction motion, which is particularly important for tumours in the thorax and abdomen. Common methods to account for motion are to introduce a margin or to convolve the static dose distribution wit...

journal_title：Physics in medicine and biology

authors： Chan TC,Bortfeld T,Tsitsiklis JN

更新日期：2006-05-21 00:00:00

abstract：:Several studies have been appeared, up to now, that indicate the effect of accurate simulation on dose received by different substructures of the eye, irradiated by external beams of short-range radiation such as electron. Different representations of the eye have consequently been introduced. Their accuracies depend ...

journal_title：Physics in medicine and biology

authors： Vejdani-Noghreiyan A,Ebrahimi-Khankook A

更新日期：2019-07-02 00:00:00

abstract：:The inadequate visibility of microcalcifications-small calcium deposits that cue radiologists to early stages of cancer-is a major limitation in current designs of dedicated breast computed tomography (bCT). This limitation has previously been attributed to the constituent components, spatial resolution, and utilized ...

journal_title：Physics in medicine and biology

authors： Ghazi P

更新日期：2020-12-04 00:00:00

abstract：:The energy dependence of alanine/EPR dosimetry, in terms of absorbed dose-to-water for clinical 6, 10, 25 MV x-rays and 60Co gamma-rays was investigated by measurements and Monte Carlo (MC) calculations. The dose rates were traceable to the NRC primary standard for absorbed dose, a sealed water calorimetry. The electr...

journal_title：Physics in medicine and biology

authors： Zeng GG,McEwen MR,Rogers DW,Klassen NV

更新日期：2004-01-21 00:00:00

abstract：:Monte Carlo-based simulation of positron emission tomography (PET) data plays a key role in the design and optimization of data correction and processing methods. Our first aim was to adapt and configure the PET-SORTEO Monte Carlo simulation program for the geometry of the widely distributed Inveon PET preclinical sca...

journal_title：Physics in medicine and biology

authors： Boisson F,Wimberley CJ,Lehnert W,Zahra D,Pham T,Perkins G,Hamze H,Gregoire MC,Reilhac A

更新日期：2013-10-07 00:00:00

abstract：:A leaf-setting algorithm is developed for generating arbitrary beam intensity profiles in discrete levels using dynamic multileaf collimators (DMLCs). The algorithm starts with the algebraic expression for the area under the beam profile. It is shown that the coefficients in this expression can be transformed into the...

journal_title：Physics in medicine and biology

authors： Ma L,Boyer AL,Xing L,Ma CM

更新日期：1998-06-01 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：:Medulloblastoma treatment involves irradiation of the entire central nervous system, i.e. craniospinal irradiation (CSI). This is associated with the significant exposure of large volumes of healthy tissue and there is growing concern regarding treatment-associated side effects. The current study compares out-of-field...

journal_title：Physics in medicine and biology

authors： De Saint-Hubert M,Verellen D,Poels K,Crijns W,Magliona F,Depuydt T,Vanhavere F,Struelens L

更新日期：2017-07-07 00:00:00

abstract：:Two detectors for fast two-dimensional (2D) and quasi-three-dimensional (quasi-3D) verification of the dose delivered by radiotherapy beams have been developed at University and Istituto Nazionale di Fisica Nucleare (INFN) of Torino. The Magic Cube is a stack of strip-segmented ionization chambers interleaved with wat...

journal_title：Physics in medicine and biology

authors： Cirio R,Garelli E,Schulte R,Amerio S,Boriano A,Bourhaleb F,Coutrakon G,Donetti M,Giordanengo S,Koss P,Madon E,Marchetto F,Nastasi U,Peroni C,Santuari D,Sardo A,Scielzo G,Stasi M,Trevisiol E

更新日期：2004-08-21 00:00:00

abstract：:The problem of fluorescence diffuse optical tomography consists in localizing fluorescent markers from near-infrared light measurements. Among the different available acquisition modalities, the time-resolved modality is expected to provide measurements of richer information content. To extract this information, the m...

journal_title：Physics in medicine and biology

authors： Ducros N,Hervé L,Da Silva A,Dinten JM,Peyrin F

更新日期：2009-12-07 00:00:00

abstract：:To replace the conventional pinhole (normal cone-beam) collimator, a novel skew-slit collimator was previously proposed and a Novikov-type algorithm developed to reconstruct images using the skew-slit geometry. The goal of this paper is to develop a reconstruction algorithm that has better noise control than the Novik...

journal_title：Physics in medicine and biology

authors： Tang Q,Zeng GL,Huang Q

更新日期：2006-12-07 00:00:00

abstract：:The use of liquid ionization chambers in radiotherapy has grown during the past few years. While for air ionization chambers the k(TP) correction for air mass density due to pressure and temperature variations is well known, less work has been done on the case of liquid ionization chambers, where there is still the ne...

journal_title：Physics in medicine and biology

authors： Gómez F,González-Castaño D,Díaz-Botana P,Pardo-Montero J

更新日期：2014-06-07 00:00:00