Portal dose image (PDI) prediction for dosimetric treatment verification in radiotherapy. I. An algorithm for open beams.

abstract：PURPOSE:The authors combine the registration of 2D beam's eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). METHODS:During treatment of lung SBRT cases...

journal_title：Medical physics

authors： Bryant JH,Rottmann J,Lewis JH,Mishra P,Keall PJ,Berbeco RI

更新日期：2014-12-01 00:00:00

abstract：:We have studied the effect of real-time optical image processing (OIP) in an image intensifier/television (II-TV) radiographic imaging system by using a liquid-crystal display (LCD) placed between the II and the TV camera. The LCD compresses the dynamic range of the transmitted image by modulating the spatial distribu...

journal_title：Medical physics

authors： Lam KL,Chan HP,Doi K

更新日期：1988-11-01 00:00:00

abstract：PURPOSE:Tumor grading is an important part of breast cancer diagnosis and currently requires biopsy as its standard. Here, the authors investigate quantitative ultrasound parameters in locally advanced breast cancers that can potentially separate tumors from normal breast tissue and differentiate tumor grades. METHODS...

journal_title：Medical physics

authors： Tadayyon H,Sadeghi-Naini A,Wirtzfeld L,Wright FC,Czarnota G

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer. METHOD:Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermo...

journal_title：Medical physics

authors： Donovan EM,James H,Bonora M,Yarnold JR,Evans PM

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:The repair rate conventionally assumed to be constant during the entire radiation course. However, increasing evidences from animal studies show that the repair process may slow down with time and the experimental data does not fit an exponential pattern. To address this enigma, we presented a generalized linea...

journal_title：Medical physics

authors： Huang Z,Mayr NA,Lo SS,McLawhorn R,Gao M,Liu T,Yuh W

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Accurate detection of pulmonary nodules remains a technical challenge in computer-aided diagnosis systems because some nodules may adhere to the blood vessels or the lung wall, which have low contrast compared to the surrounding tissues. In this paper, the analysis of typical shape features of candidate nodules...

journal_title：Medical physics

authors： Wang B,Tian X,Wang Q,Yang Y,Xie H,Zhang S,Gu L

更新日期：2015-03-01 00:00:00

abstract：PURPOSE:Total and regional body composition are important indicators of health and mortality risk, but their measurement is usually restricted to controlled environments in clinical settings with expensive and specialized equipment. A method that approaches the accuracy of the current gold standard method, dual-energy ...

journal_title：Medical physics

authors： Tian IY,Ng BK,Wong MC,Kennedy S,Hwaung P,Kelly N,Liu E,Garber AK,Curless B,Heymsfield SB,Shepherd JA

更新日期：2020-12-01 00:00:00

abstract：PURPOSE:Current treatment planning for 90 Y radioembolization estimates lung mean dose (LMD) by measuring the lung shunt fraction (LSF) from 99m Tc-macroaggregated albumin (MAA) planar imaging and assuming a 1-kg lung mass. This methodology, however, overestimates LSF and LMD and could therefore unnecessarily limit the...

journal_title：Medical physics

authors： Lopez B,Mahvash A,Lam MGEH,Kappadath SC

更新日期：2019-09-01 00:00:00

abstract：:The contribution of a commercially available diode matrix (MapCHECK, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation ...

journal_title：Medical physics

authors： Borca VC,Pasquino M,Ozzello F,Tofani S

更新日期：2009-04-01 00:00:00

abstract：:The dissemination of scientific advances has changed little since the first peer-reviewed journal was published in 1665 - that is, until this past decade. The print journal, delivered by mail and stored on office shelves and in library reading rooms around the world, has been transformed by immediate, on-demand access...

journal_title：Medical physics

authors： Armato S,Hendee W,Marshall C,Curran B

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Periprocedural assessment of tissue perfusion by imaging methods could improve outcome control during treatment of peripheral vascular disease. Currently, endovascular revascularization treatments are assessed by planar angiography which only allows for qualitative inspection of blood flow in vessels. In this p...

journal_title：Medical physics

authors： Giordano M,Vonken EJ,Bertram M,Mali W,Viergever MA,Neukirchen C

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:Osteoporosis is a common bone disease associated with increased risk of low-trauma fractures leading to substantial morbidity, mortality, and financial costs. Clinically, osteoporosis is defined by low bone mineral density (BMD); however, increasing evidence suggests that trabecular bone (TB) microarchitectural...

journal_title：Medical physics

authors： Saha PK,Liu Y,Chen C,Jin D,Letuchy EM,Xu Z,Amelon RE,Burns TL,Torner JC,Levy SM,Calarge CA

更新日期：2015-09-01 00:00:00

abstract：PURPOSE:Several new technologies for single photon emission computed tomography (SPECT) instrumentation with parallel-hole collimation have been proposed to improve detector sensitivity and signal collection efficiency. Benefits from improved signal efficiency include shorter acquisition times and lower dose requiremen...

journal_title：Medical physics

authors： Lee TC,Ellin JR,Huang Q,Shrestha U,Gullberg GT,Seo Y

更新日期：2014-11-01 00:00:00

abstract：PURPOSE:As radiation therapy evolves toward more adaptive techniques, image guidance plays an increasingly important role, not only in patient setup but also in monitoring the delivered dose and adapting the treatment to patient changes. This study aimed to validate a method for evaluation of delivered intensity modula...

journal_title：Medical physics

authors： Moteabbed M,Sharp GC,Wang Y,Trofimov A,Efstathiou JA,Lu HM

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:Many clinical applications depend critically on the accurate differentiation and classification of different types of materials in patient anatomy. This work introduces a unified framework for accurate nonlinear material decomposition and applies it, for the first time, in the concept of triple-energy CT (TECT)...

journal_title：Medical physics

authors： Zhao W,Vernekohl D,Han F,Han B,Peng H,Yang Y,Xing L,Min JK

更新日期：2018-07-01 00:00:00

abstract：:Digital tomosynthesis is an imaging technique to produce a tomographic image from a series of angular digital images in a manner similar to conventional focal plane tomography. Unlike film focal plane tomography, the acquisition of the data in a C-arm geometry causes the image receptor to be positioned at various angl...

journal_title：Medical physics

authors： Rakowski JT,Dennis MJ

更新日期：2006-08-01 00:00:00

abstract：:Skin entrance doses of patients undergoing interventional x-ray procedures are capable of causing skin damage and should be monitored routinely. Single TLD chips are not suitable because the location of maximum skin exposure cannot be predicted. Most photographic films are too sensitive at diagnostic x-ray energies fo...

journal_title：Medical physics

authors： Geise RA,Schueler BA,Lien W,Jones SC

更新日期：1997-10-01 00:00:00

abstract：PURPOSE:This article aims to introduce a novel algorithm for fast beam angle selection in intensity modulated radiotherapy (IMRT). METHODS:The algorithm models the optimization problem as a beam angle ranking problem and chooses suitable beam angles according to their rank. A new parameter called "beam intensity profi...

journal_title：Medical physics

authors： Vaitheeswaran R,Narayanan VK,Bhangle JR,Nirhali A,Kumar N,Basu S,Maiya V

更新日期：2010-12-01 00:00:00

abstract：:Results of an 18-alternative forced-choice experiment have shown that observers were capable of detecting a signal with a contrast of 1 in terms of 10-bit data which were displayed on a CRT monitor with an 8-bit video generator and a window width setting of 1024. We investigated the conditions under which 10-bit signa...

journal_title：Medical physics

authors： Giger ML,Ohara K,Doi K

更新日期：1986-05-01 00:00:00

abstract：PURPOSE:Couch-mounted cone-beam computed tomography (CBCT) imaging devices with independently rotatable x-ray source and flat-panel detector arms for acquisitions of arbitrary regions of interest (ROI) have recently been introduced in image-guided radiotherapy (IGRT). This work analyzes mechanical limitations and gravi...

journal_title：Medical physics

authors： Keuschnigg P,Kellner D,Fritscher K,Zechner A,Mayer U,Huber P,Sedlmayer F,Deutschmann H,Steininger P

更新日期：2017-01-01 00:00:00

abstract：:The effective energy of the x-ray beam from linear accelerators changes as a function of the position in the beam due to nonuniform filtration by the flattening filter. In this work, the transmittance through a water column was measured in good geometry and the beam quality characterized in units of HVL in water. Meas...

journal_title：Medical physics

authors： Hanson WF,Berkley LW,Peterson M

更新日期：1980-03-01 00:00:00

abstract：PURPOSE:In recent years, laser-based acceleration of charged particles has rapidly progressed and medical applications, e.g., in radiotherapy, might become feasible in the coming decade. Requirements are monoenergetic particle beams with long-term stable and reproducible properties as well as sufficient particle intens...

journal_title：Medical physics

authors： Beyreuther E,Enghardt W,Kaluza M,Karsch L,Laschinsky L,Lessmann E,Nicolai M,Pawelke J,Richter C,Sauerbrey R,Schlenvoigt HP,Baumann M

更新日期：2010-04-01 00:00:00

abstract：PURPOSE:To compare optimization characteristics, plan quality, and treatment delivery efficiency between total marrow irradiation (TMI) plans using the new TomoTherapy graphic processing unit (GPU) based dose engine and CPU/cluster based dose engine. METHODS:Five TMI plans created on an anthropomorphic phantom were op...

journal_title：Medical physics

authors： Nalichowski A,Burmeister J

更新日期：2013-07-01 00:00:00

abstract：PURPOSE:The recent development of multifocal stereotactic radiosurgery (SRS) using a single isocenter volumetric modulated arc theory (VMAT) technique warrants a re-examination of the quality assurance (QA) tolerances for routine mechanical QA recommended by the American Association of Physicists in Medicine Task Group...

journal_title：Medical physics

authors： Faught AM,Trager M,Yin FF,Kirkpatrick J,Adamson J

更新日期：2016-10-01 00:00:00

abstract：:Extensive information has been made available relative to the physical aspects necessary for calculation of radiation absorbed dose from radiopharmaceuticals. A similar data base for the biological factors involved in these calculations has not been documented as thoroughly. The authors present an extensive literature...

journal_title：Medical physics

authors： Flannery A,Veber J,Greenfield MA,McIntyre AB,Hamilton DR

更新日期：1980-05-01 00:00:00

abstract：:The intensity of Compton scattered photons is directly proportional to the electron density of a substance; therefore it is possible to detect changes in electron density by this noninvasive method. The source-detector geometry has been varied to study the effects of geometry on the calculated electron density values,...

journal_title：Medical physics

authors： Huddleston AL,Sackler JP

更新日期：1985-01-01 00:00:00

abstract：PURPOSE:To evaluate the patient positioning accuracy and reproducibility of two commercially available immobilization systems for Stereotactic Body Radiotherapy (SBRT) treatment. METHODS:Forty one patients with lung (n=21) or liver (n=20) malignancies were assigned to one of the two immobilization devices: Elekta ster...

journal_title：Medical physics

authors： Cao M,Cao N,Cardenes H,Fakiris A,Desrosiers C,Das I

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:New preclinical image-guided irradiators and treatment planning systems represent a huge progress in radiobiology. Nevertheless, quality control of preclinical treatments is not as advanced as in clinical radiotherapy and in vivo dosimetry is less developed. In this study, we evaluate the use of a scintillating...

journal_title：Medical physics

authors： Le Deroff C,Pérès EA,Ledoux X,Toutain J,Frelin-Labalme AM

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Material-specific imaging and virtual monochromatic imaging/analysis are the two forms of spectral imaging in CT implemented via either energy-integration or photon-counting data acquisition. Aimed at further understanding the fundamentals and providing guidelines on its design and implementation, we quantitati...

journal_title：Medical physics

authors： Tang X,Ren Y

更新日期：2021-01-07 00:00:00

abstract：:In this article, we report on the development of a simple and accurate method for quality assurance of electron beam output and energy. Aluminum disks of thicknesses d(max) or d50 of the particular electron energy are positioned sequentially over a parallel-plate ion chamber and the ratio of the two signals is compare...

journal_title：Medical physics

authors： Woo MK,Videla NG

更新日期：2004-05-01 00:00:00