Three dimensional intensity modulated brachytherapy (IMBT): dosimetry algorithm and inverse treatment planning.

abstract：:The minimum margins required to compensate for random geometric uncertainties in the delivery of radiotherapy treatment were determined for a spherical Clinical Target Volume, using an analytic model for the cumulative dose. Margins were calculated such that the minimum dose in the target would be no less than 95% of ...

journal_title：Medical physics

authors： Witte MG,van der Geer J,Schneider C,Lebesque JV,van Herk M

更新日期：2004-11-01 00:00:00

abstract：PURPOSE:When an intensity-modulated radiation beam is delivered to a moving target, the interplay effect between dynamic beam delivery and the target motion due to miss-synchronization can cause unpredictable dose delivery. The portal dose image in electronic portal imaging device (EPID) represents radiation attenuated...

journal_title：Medical physics

authors： Yeo IJ,Jung JW,Yi BY,Kim JO

更新日期：2013-05-01 00:00:00

abstract：PURPOSE:To find an upper bound on the maximum dose reduction possible for any reconstruction algorithm, analytic or iterative, that result from the inclusion of the data statistics. The authors do not analyze noise reduction possible from prior knowledge or assumptions about the object. METHODS:The authors examined th...

journal_title：Medical physics

authors： Hsieh SS,Chesler DA,Fleischmann D,Pelc NJ

更新日期：2016-03-01 00:00:00

abstract：:Intensity modulated radiation therapy (IMRT) with a dynamic multileaf collimator (DMLC) requires synchronization of DMLC leaf motion with dose delivery. A delay in DMLC communication is known to cause leaf lag and lead to dosimetric errors. The errors may be exacerbated by gated operation. The purpose of this study wa...

journal_title：Medical physics

authors： Duan J,Shen S,Fiveash JB,Brezovich IA,Popple RA,Pareek PN

更新日期：2003-08-01 00:00:00

abstract：:A proton beam is extracted from the 200-MeV linear accelerator at the Fermi National Accelerator Laboratory to investigate the efficacy of proton radiography in medical diagnosis. Fluence rates from 2 X 10(3) to 2 X 10(5) protons/cm2s over a 28-cm diameter field are obtained with a full width at half-maximum beam-ener...

journal_title：Medical physics

authors： Curry J,Steward VW

更新日期：1978-05-01 00:00:00

abstract：PURPOSE:To quantitatively characterize the interfractional anatomic variations in post-operative radiation therapy (RT) for prostate bed, so that appropriate strategy that can fully address these variations can be developed. METHODS:A total of 102 daily pre-treatment CT acquired using an in-room CT (CTVision, Siemens)...

journal_title：Medical physics

authors： Liu F,Ahunbay E,Christian R,Lawton C,Wang D,Li X

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Magnetic particle imaging (MPI) is a relatively new method to image the spatial distribution of magnetic nanoparticle (MNP) tracers administered to the body with high spatial and temporal resolution using an inhomogeneous magnetic field. The spatial information of the MNP's is encoded using a field free point (...

journal_title：Medical physics

authors： Top CB,Güngör A,Ilbey S,Güven HE

更新日期：2019-04-01 00:00:00

abstract：PURPOSE:Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the hi...

journal_title：Medical physics

authors： Larraga-Gutierrez JM,Garcia-Hernandez D,Garcia-Garduno OA,Galvan de la Cruz OO,Ballesteros-Zebadua P,Esparza-Moreno KP

更新日期：2012-10-01 00:00:00

abstract：:Vessel size measurement is perhaps the most often performed quantitative analysis in diagnostic and interventional angiography. Although automated vessel sizing techniques are generally considered to have good accuracy and precision, we have observed that clinicians rarely use these techniques in standard clinical pra...

journal_title：Medical physics

authors： Hoffmann KR,Dmochowski J,Nazareth DP,Miskolczi L,Nemes B,Gopal A,Wang Z,Rudin S,Bednarek DR

更新日期：2003-04-01 00:00:00

abstract：:The synchronization of dynamic multileaf collimator (DMLC) response with respiratory motion is critical to ensure the accuracy of DMLC-based four dimensional (4D) radiation delivery. In practice, however, a finite time delay (response time) between the acquisition of tumor position and multileaf collimator response ne...

journal_title：Medical physics

authors： Vedam S,Docef A,Fix M,Murphy M,Keall P

更新日期：2005-06-01 00:00:00

abstract：:Clinical and biological evidence suggest that the success of GRID therapy in debulking large tumors depends on the high peak-to-valley contrast in the dose distribution. In this study, we show that the peaks and valleys can be significantly blurred out by respiration-induced tumor motion, possibly affecting the clinic...

journal_title：Medical physics

authors： Naqvi SA,Mohiuddin MM,Ha JK,Regine WF

更新日期：2008-10-01 00:00:00

abstract：:In x-ray spectral measurement using a semiconductor detector system, accurate positioning of the detector in front of the anode is very important. This needs accurate determination of the focal spot position on the target in an x-ray tube. We present a simple technique to determine the focal spot position accurately. ...

journal_title：Medical physics

authors： Kubota H,Ozaki Y,Matsumoto M,Kanamori H

更新日期：1993-07-01 00:00:00

abstract：:Complementary metal-oxide-semiconductors (CMOS) active pixel sensors can be optically coupled to CsI:Tl phosphors forming a indirect active pixel flat panel imager (APFPI) for high performance medical imaging. The aim of this work is to determine the x-ray imaging capabilities of CMOS-based APFPI and study the signal ...

journal_title：Medical physics

authors： Arvanitis CD,Bohndiek SE,Blakesley J,Olivo A,Speller RD

更新日期：2009-01-01 00:00:00

abstract：PURPOSE:The authors investigate the extent to which Response Evaluation Criteria in Solid Tumors (RECIST) can predict tumor volumes in ideal geometric settings and using clinical data. METHODS:The authors consider a hierarchy of models including uniaxial ellipsoids, general ellipsoids, and composites of ellipsoids, us...

journal_title：Medical physics

authors： Levine ZH,Galloway BR,Peskin AP,Heussel CP,Chen JJ

更新日期：2011-05-01 00:00:00

abstract：PURPOSE:To develop and evaluate the impact on lesion conspicuity of a software-based x-ray scatter correction algorithm for digital breast tomosynthesis (DBT) imaging into which a precomputed library of x-ray scatter maps is incorporated. METHODS:A previously developed model of compressed breast shapes undergoing mamm...

journal_title：Medical physics

authors： Feng SS,D'Orsi CJ,Newell MS,Seidel RL,Patel B,Sechopoulos I

更新日期：2014-03-01 00:00:00

abstract：PURPOSE:In radiotherapy, it is important to predict the response of tumors to irradiation prior to the treatment. This is especially important for hypoxic tumors, which are known to be highly radioresistant. Mathematical modeling based on the dose distribution, biological parameters, and medical images may help to impr...

journal_title：Medical physics

authors： Espinoza I,Peschke P,Karger CP

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:The purpose of this study is to evaluate the feasibility of kilovoltage cone-beam CT (CBCT) images that are obtained with the Varian On-Board Imager in dose calculation at each radiation therapy. METHODS:CBCT images are commonly degraded by scattered radiations originating in the patient's body, and so the CT ...

journal_title：Medical physics

authors： Usui K,Ogawa K,Kunieda E

更新日期：2012-06-01 00:00:00

abstract：:The availability of digital radiographic imaging on simulators has led to the investigation of a number of new imaging possibilities, including digital linear tomography (tomosynthesis). It has been shown that a single set of projections in this case is sufficient to reconstruct images from multiple planes, including ...

journal_title：Medical physics

authors： Zwicker RD,Atari NA

更新日期：1997-06-01 00:00:00

abstract：:Using high-energy photon and electron beams, the response of two solid water parallel-plate chambers is evaluated against a PTW (Physicallsch-Technische Werkstatten) Farmer-type chamber. These two chambers are (1) a Memorial "Holt" chamber which was further modified by this author to take advantage of electrically con...

journal_title：Medical physics

authors： Kubo H

更新日期：1993-03-01 00:00:00

abstract：PURPOSE:To develop a novel aperture-based algorithm for volumetric modulated are therapy (VMAT) treatment plan optimization with high quality and high efficiency. METHODS:The VMAT optimization problem is formulated as a large-scale convex programming problem solved by a column generation approach. The authors consider...

journal_title：Medical physics

authors： Men C,Romeijn HE,Jia X,Jiang SB

更新日期：2010-11-01 00:00:00

abstract：PURPOSE:Temporal subtraction is used to detect the interval change in chest radiographs and aid radiologists in patient diagnosis. This method registers two temporally different images by geometrically warping the lung region, or "lung mask," of a previous radiographic image to align with the current image. The gray le...

journal_title：Medical physics

authors： Armato SG 3rd,Sensakovic WF,Passen SJ,Engelmann R,MacMahon H

更新日期：2009-12-01 00:00:00

abstract：PURPOSE:To develop a pencil beam dose calculation algorithm for scanned proton beams that improves modeling of scatter events. METHODS:Our pencil beam algorithm (PBA) was developed for calculating dose from monoenergetic, parallel proton beams in homogeneous media. Fermi-Eyges theory was implemented for pencil beam tr...

journal_title：Medical physics

authors： Chapman J,Fontenot J,Newhauser W,Hogstrom K

更新日期：2012-06-01 00:00:00

abstract：:MR acoustic radiation force (ARF) imaging was developed for measuring tiSsue elastic properties using focused ultrasound to deliver a localized tissue motion. In this study, an imaging ultrasound transducer was mounted on the focused ultrasound transducer and ultrasound motion tracking was performed simultaneously to ...

journal_title：Medical physics

authors： Huang Y,Curiel L,Kukic A,Plewes DB,Chopra R,Hynynen K

更新日期：2009-06-01 00:00:00

abstract：PURPOSE:To develop and test the feasibility of a two-pass iterative reconstruction algorithm with material decomposition designed to obtain quantitative iodine measurements in digital breast tomosynthesis. METHODS:Contrast-enhanced mammography has shown promise as a cost-effective alternative to magnetic resonance ima...

journal_title：Medical physics

authors： Michielsen K,Rodríguez-Ruiz A,Reiser I,Nagy JG,Sechopoulos I

更新日期：2020-10-01 00:00:00

abstract：PURPOSE:An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as(99m)Tc or most positron emission tomography radiopharmaceuticals. METHODS:By evaluation of the resul...

journal_title：Medical physics

authors： Oliveira PA,Santos JA

更新日期：2014-07-01 00:00:00

abstract：PURPOSE:We propose a new method for efficient particle transportation in voxelized geometry for Monte Carlo simulations. We describe its use for calculating dose distribution in CT images for radiation therapy. MATERIAL AND METHODS:The proposed approach, based on an implicit volume representation named segmented volum...

journal_title：Medical physics

authors： Sarrut D,Guigues L

更新日期：2008-04-01 00:00:00

abstract：PURPOSE:A prototype in-house program was developed to assist deriving image guidance shifts clinically using our 4DCT method for lung SBRT. METHODS:Our in-house prototype program was implemented in MATLAB. The 4D DICOM CT dataset of interest is imported by the program from AW and subsequently accepts input from the us...

journal_title：Medical physics

authors： Wang B,Sarkar V,Busselberg C,Rassiah-Szegedi P,Zhao H,Huang Y,Szegedi M,Salter B

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:The aim of this study was to develop a dose calculation method which is applicable to the interseed attenuation and the geometry lacking the equilibrium radiation scatter conditions in brachytherapy. METHODS:The dose obtained from measurement with a radiophotoluminescent glass rod dosimeter (GRD) was compared ...

journal_title：Medical physics

authors： Tanaka K,Tateoka K,Asanuma O,Kamo K,Bengua G,Sato K,Ueda T,Takeda H,Takagi M,Hareyama M,Takada J

更新日期：2011-06-01 00:00:00

abstract：:In many of brachytherapy procedures, a large amount of radioactive sources are used to deliver desired doses to the target volume. It is both the federal regulation recommendation (U.S. Nuclear Regulatory Commission, 10 CFR 35.432) and recommendations of the American Association of Physicists in Medicine (AAPM) [Kutch...

journal_title：Medical physics

authors： Yue NJ,Haffty BG,Yue J

更新日期：2007-06-01 00:00:00

abstract：:Interstitial brachytherapy for carcinoma of the prostate is achieved through the use of a configuration of radioactive seeds placed in a manner that delivers a customized, reasonably uniform dose to the target volume. Accurate dose delivery depends on both precise seed placement and reliable seed strength in the impla...

journal_title：Medical physics

authors： Rosenzweig DP,Schell MC,Yu Y

更新日期：2000-01-01 00:00:00