Optimization of tumour control probability for heterogeneous tumours in fractionated radiotherapy treatment protocols.

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：:The signal-to-noise ratio (SNR) in x-ray imaging can be increased using a photon counting detector which could allow for rejecting electronics noise and for weighting x-ray photons according to their energies. This approach, however, was not feasible for a long time because photon counting x-ray detectors with very hi...

journal_title：Physics in medicine and biology

authors： Shikhaliev PM

更新日期：2009-08-21 00:00:00

abstract：:We present a method based on spectral theory for the shape analysis of carpal bones of the human wrist. We represent the cortical surface of the carpal bone in a coordinate system based on the eigensystem of the two-dimensional Helmholtz equation. We employ a metric--global point signature (GPS)--that exploits the sca...

journal_title：Physics in medicine and biology

authors： Chaudhari AJ,Leahy RM,Wise BL,Lane NE,Badawi RD,Joshi AA

更新日期：2014-02-21 00:00:00

abstract：:A detailed Monte Carlo model of a proton therapy treatment head was commissioned to simulate the delivery of small field proton treatments. Small fields are challenging in the planning and quality assurance process because of aperture scattering and dosimetric disequilibrium. Four patients with small fields used in al...

journal_title：Physics in medicine and biology

authors： Bednarz B,Daartz J,Paganetti H

更新日期：2010-12-21 00:00:00

abstract：:We report on a radiographic measurement of an ex vivo human knee using a grating-based phase-contrast imaging setup and a medical x-ray tube at a tube voltage of 70 kV. The measurement has been carried out using a Talbot-Lau setup that is suitable to achieve a high visibility in the energy regime of medical imaging. I...

journal_title：Physics in medicine and biology

authors： Horn F,Gelse K,Jabari S,Hauke C,Kaeppler S,Ludwig V,Meyer P,Michel T,Mohr J,Pelzer G,Rieger J,Riess C,Seifert M,Anton G

更新日期：2017-08-01 00:00:00

abstract：:We investigate the effect of multiple scattering on the optical coherence tomography (OCT) signal and the Doppler OCT signal of flowing blood. Doppler OCT measurements at 1300 nm are performed on flowing diluted porcine blood with hematocrit ranging between 0% and 15%. Measured blood hematocrit and mean red blood cell...

journal_title：Physics in medicine and biology

authors： Kalkman J,Bykov AV,Streekstra GJ,van Leeuwen TG

更新日期：2012-04-07 00:00:00

abstract：:Cylindrical ionization chambers with varying radii have been used to determine the displacement effect at distances between 10 mm and 40 mm from 60Co and 192Ir brachytherapy sources. Agreement with published values of the displacement factor for external 60Co beams is obtained. The shift between the centre of the ioni...

journal_title：Physics in medicine and biology

authors： Tölli H,Johansson KA

更新日期：1993-10-01 00:00:00

abstract：:Practical dosimeters in brachytherapy, such as thermoluminescent dosimeters (TLD) and diodes, are usually calibrated against low-energy megavoltage beams. To measure absolute dose rate near a brachytherapy source, it is necessary to establish the energy response of the detector relative to that of the calibration ener...

journal_title：Physics in medicine and biology

authors： Das RK,Li Z,Perera H,Williamson JF

更新日期：1996-06-01 00:00:00

abstract：:In external beam radiation therapy, radioactive beams offer the best clinical solution to simultaneously treat and in vivo monitor the dose delivery and tumor response using PET or PET-CT imaging. However, difficulties mainly linked to the low production efficiency have so far limited their use. This study is devoted ...

journal_title：Physics in medicine and biology

authors： Lazzeroni M,Brahme A

更新日期：2011-03-21 00:00:00

abstract：:Voltage-sensitive dyes are an important tool in visualizing electrical activity in cardiac tissue. Until today, they have mainly been applied in cardiac electrophysiology to subsurface imaging. In the present study, we assess different imaging methods used in optical tomography with respect to their effectiveness in v...

journal_title：Physics in medicine and biology

authors： Bernus O,Wellner M,Mironov SF,Pertsov AM

更新日期：2005-01-21 00:00:00

abstract：:Ho-166 is a combined beta-gamma emitter of which the betas can be used therapeutically. From the 81 keV gammas of Ho-166, SPECT images can be obtained, which give opportunities to guide Ho-166 therapy. Accurate reconstruction of Ho-166 images is currently hampered by photopeak-scatter in the patient, down-scatter in t...

journal_title：Physics in medicine and biology

authors： de Wit TC,Xiao J,Nijsen JF,van het Schip FD,Staelens SG,van Rijk PP,Beekman FJ

更新日期：2006-10-07 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：:The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, o...

journal_title：Physics in medicine and biology

authors： Deeley MA,Chen A,Datteri R,Noble JH,Cmelak AJ,Donnelly EF,Malcolm AW,Moretti L,Jaboin J,Niermann K,Yang ES,Yu DS,Yei F,Koyama T,Ding GX,Dawant BM

更新日期：2011-07-21 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：: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：:Automatic tube current modulation (TCM) is used in modern CT devices. This is implemented in the numerical calculation of dose conversion coefficients for CT examinations. For four models of adults, the female and male reference models of ICRP and ICRU and a lighter and a heavier female model, dose conversion coeffici...

journal_title：Physics in medicine and biology

authors： Schlattl H,Zankl M,Becker J,Hoeschen C

更新日期：2010-10-21 00:00:00

abstract：:This work modified the commonly used Monte Carlo tool package GATE by developing a new 'multiPatchPET' system so that GATE users can easily simulate PET systems with irregular geometries. The motivation was to design a brain PET scanner with high sensitivity. It is known that compact PET scanners with a large solid co...

journal_title：Physics in medicine and biology

authors： Chen G,Weng F,Hong X,Tao W,Zhao Z,Peng Q,Huang Q

更新日期：2018-09-06 00:00:00

abstract：:This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase spa...

journal_title：Physics in medicine and biology

authors： Pipek J,Novotný J,Novotný J,Kozubíková P

更新日期：2014-12-21 00:00:00

abstract：:Magnetic resonance and ultrasound elastography techniques are now important tools for staging high-grade fibrosis in patients with chronic liver disease. However, uncertainty remains about the effects of simple accumulation of fat (steatosis) and inflammation (steatohepatitis) on the parameters that can be measured us...

journal_title：Physics in medicine and biology

authors： Parker KJ,Ormachea J,Drage MG,Kim H,Hah Z

更新日期：2018-05-17 00:00:00

abstract：:The purpose of this study was to determine the performance of a single lutetium oxy-orthosilicate (LSO) crystal layer High Resolution Research Tomograph (HRRT) positron emission tomography (PET) scanner. The HRRT is a high resolution PET scanner designed for human brain and small animal imaging. The scanner consists o...

journal_title：Physics in medicine and biology

authors： Boellaard R,Buijs F,de Jong HW,Lenox M,Gremillion T,Lammertsma AA

更新日期：2003-02-21 00:00:00

abstract：:Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15-20 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotr...

journal_title：Physics in medicine and biology

authors： Uzunov NM,Melendez-Alafort L,Bello M,Cicoria G,Zagni F,De Nardo L,Selva A,Mou L,Rossi-Alvarez C,Pupillo G,Di Domenico G,Uccelli L,Boschi A,Groppi F,Salvini A,Taibi A,Duatti A,Martini P,Pasquali M,Loriggiola M,Mare

更新日期：2018-09-19 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：: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：:Input functions required for positron emission tomography (PET) tracer kinetic modeling are often obtained from arterial blood. In some situations, using short-lived radiotracers, e.g. [(15)O]water, rapid sample handling is required. A method used at several facilities is to pump blood through a detector system at a c...

journal_title：Physics in medicine and biology

authors： Laymon CM,Sashin D,Carney JP,Ruszkiewicz J,Altenburger D,Becker CR,Lopresti BJ,Mason NS,Mountz JM,Price JC,Schavey R,Mathis CA

更新日期：2008-01-21 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

abstract：:A mathematical model has been constructed to simulate the response of cells in vitro to fractionated doses of radiation. The model is capable of describing most of the radiobiological functions that are commonly studied. Input data are measurable cell properties. The details of the model and methods of acquiring the i...

journal_title：Physics in medicine and biology

authors： Niederer J,Cunningham JR

更新日期：1976-09-01 00:00:00

abstract：:The performance of a light sharing and recirculation mechanism that allows the extraction of depth of interaction (DOI) are investigated in this paper, with a particular focus on timing. In parallel, a method to optimize the coincidence time resolution (CTR) of PET detectors by use of the DOI information is proposed a...

journal_title：Physics in medicine and biology

authors： Pizzichemi M,Polesel A,Stringhini G,Gundacker S,Lecoq P,Tavernier S,Paganoni M,Auffray E

更新日期：2019-08-07 00:00:00

abstract：:An experimental investigation of the central axis depth-dose and stopping rate distribution of the SIN biomedical pion beam is reported. The pion stopping rate in a thin disc of tissue-equivalent plastic was determined using a counter telescope. The dose rate at the position of this dic 'target' was measured using a s...

journal_title：Physics in medicine and biology

authors： Nordell B,Baarli J,Sullivan AH,Zielczynski M

更新日期：1977-05-01 00:00:00

abstract：:This work describes the dosimetric commissioning of the treatment planning system (TPS) RayStation v6.1 from RaySearch Laboratories (Stockholm, Sweden) for a synchrotron-based scanned proton beam delivery with isocentric and non-isocentric setups at MedAustron. Focus was on the comparison of the pencil beam (PBv4.1) a...

journal_title：Physics in medicine and biology

authors： Carlino A,Böhlen T,Vatnitsky S,Grevillot L,Osorio J,Dreindl R,Palmans H,Stock M,Kragl G

更新日期：2019-08-28 00:00:00

abstract：:It is well known that the experimental dosimetry of brachytherapy sources presents a challenge. Depending on the particular-dosimeter used, measurements can suffer from poor spatial resolution (ion chambers), lack of 3D information (film) or errors due to the presence of the dosimeter itself distorting the radiation f...

journal_title：Physics in medicine and biology

authors： McJury M,Tapper PD,Cosgrove VP,Murphy PS,Griffin S,Leach MO,Webb S,Oldham M

更新日期：1999-10-01 00:00:00