Technical note: the calibration of 90Y-labeled SIR-Spheres using a nondestructive spectroscopic assay.

abstract：:Radiation therapy treatment modalities continue to develop and have become increasingly complex. With this, dose verification and quality assurance (QA) is of great importance to ensure that a prescribed dose is accurately and precisely delivered to a patient. Radiochromic film dosimetry has been adopted as a convenie...

journal_title：Medical physics

authors： Alexander K,Percy E,Olding T,Schreiner LJ,Salomons G

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:To provide specific experience-based guidance and recommendations for centers wishing to develop, validate, and implement an accurate and efficient process for directly using positron emission tomography-computed tomography (PET-CT) for the radiotherapy planning of head and neck cancer patients. METHODS:A PET-...

journal_title：Medical physics

authors： Thomas CM,Pike LC,Hartill CE,Baker S,Woods E,Convery DJ,Greener AG

更新日期：2014-04-01 00:00:00

abstract：PURPOSE:To simplify the often complex and user-dependent manual region of interest (ROI) selection process for head motion monitoring, an automatic ROI selection method was developed. METHODS:The automatic ROI selection algorithm calculated the displacements and velocities of 3D surface points between a temporally cor...

journal_title：Medical physics

authors： Kang HJ,Grelewicz Z,Wiersma RD

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Total variation minimization (TVM) is a popular and useful method for accurate CT reconstruction from few-views and limited-angle data. However, the optimization procedure of previous TVM-based algorithms is very time-consuming. The purpose of this paper was to accelerate the high image quality CT reconstructio...

journal_title：Medical physics

authors： Hou X,Teng Y,Kang Y,Qi S

更新日期：2018-02-01 00:00:00

abstract：:The BrachySeed model LS-1 is one of the latest in a series of new brachytherapy 125I seeds that have recently become available commercially for interstitial implants. The dosimetric properties of the seed were investigated analytically, experimentally, and by Monte Carlo simulation. Following the AAPM Task Group 43 fo...

journal_title：Medical physics

authors： Chan GH,Prestwich WV

更新日期：2002-02-01 00:00:00

abstract：PURPOSE:To develop an individually optimized contrast-enhanced (CE) 4D-computed tomography (CT) for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). METHODS:Ten PDA patients were enrolled. Each underwent three CT scans: a 4D-CT immediately following a CE 3D-CT and an individually optimized CE 4D-CT ...

journal_title：Medical physics

authors： Choi W,Xue M,Lane BF,Kang MK,Patel K,Regine WF,Klahr P,Wang J,Chen S,D'Souza W,Lu W

更新日期：2016-10-01 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：:This article is the first in a series on the calculation of electron dose using multiple-scattering theory. In it we develop a unified theory, which we term Gaussian multiple-scattering theory, starting from a number of contributions already in the literature: the Fermi-Eyges multiple-scattering theory, the Yang path ...

journal_title：Medical physics

authors： Jette D

更新日期：1988-03-01 00:00:00

abstract：:A water beam imaging system (WBIS) has been developed and used to verify dose distributions for intensity modulated radiotherapy using dynamic multileaf collimator. This system consisted of a water container, a scintillator screen, a charge-coupled device camera, and a portable personal computer. The scintillation ima...

journal_title：Medical physics

authors： Li JS,Boyer AL,Ma CM

更新日期：2001-12-01 00:00:00

abstract：PURPOSE:Periodic MV∕KV radiographs taken during volumetric modulated arc therapy (VMAT) for hypofractionated treatment provide guidance in intrafractional motion management. The choice of imaging frequency and timing are key components in delivering the desired dose while reducing associated overhead such as imaging do...

journal_title：Medical physics

authors： Zhang P,Hunt M,Happersett L,Cox B,Mageras G

更新日期：2012-09-01 00:00:00

abstract：PURPOSE:Magnetic resonance imaging (MRI) is increasingly used for radiotherapy target delineation, image guidance, and treatment response monitoring. Recent studies have shown that an entire external x-ray radiotherapy treatment planning (RTP) workflow for brain tumor or prostate cancer patients based only on MRI refer...

journal_title：Medical physics

authors： Koivula L,Wee L,Korhonen J

更新日期：2016-08-01 00:00:00

abstract：:A theoretical model is described for application in ultrasonic tissue characterization using a calibrated 2-D spectrum analysis method. This model relates 2-D spectra computed from ultrasonic backscatter signals to intrinsic physical properties of tissue microstructures, e.g., size, shape, and acoustic impedance. The ...

journal_title：Medical physics

authors： Liu T,Lizzi FL,Ketterling JA,Silverman RH,Kutcher GJ

更新日期：2007-03-01 00:00:00

abstract：PURPOSE:In breast radiotherapy with intensity modulation, it is a well established practice to extend the dose fluence outside the limit of the body contour to account for small changes in size and position of the target and the rest of the tissues due to respiration or to possible oedema. A simple approach is not appl...

journal_title：Medical physics

authors： Giorgia N,Antonella F,Alessandro C,Eugenio V,Luca C

更新日期：2011-07-01 00:00:00

abstract：PURPOSE:We have investigated the dosimetric errors caused by the interplay between the motions of the LINAC and the tumor during the delivery of a volume modulated arc therapy treatment. This includes the development of an IMRT QA technique, applied here to evaluate RapidArc plans of varying complexity. METHODS:An IMR...

journal_title：Medical physics

authors： Court L,Wagar M,Berbeco R,Reisner A,Winey B,Schofield D,Ionascu D,Allen AM,Popple R,Lingos T

更新日期：2010-01-01 00:00:00

abstract：:Recent absorbed-dose-based protocols allow for two methods of calibrating electron beams using plane-parallel chambers, one using the N(Co)D,w for a plane-parallel chamber, and the other relying on cross-calibration of the plane-parallel chamber in a high-energy electron beam against a cylindrical chamber which has an...

journal_title：Medical physics

authors： Stewart KJ,Seuntjens JP

更新日期：2002-03-01 00:00:00

abstract：PURPOSE:Respiratory motion in the chest region during single photon emission computed tomography (SPECT) is a major degrading factor that reduces the accuracy of image quantification. This effect is more notable when the tumor is very small, or the spatial resolution of the imaging system is less than the respiratory m...

journal_title：Medical physics

authors： Naseri M,Rajabi H,Wang J,Abbasi M,Kalantari F

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly (192)Ir with an air KERMA strength range between 20,000 and 40,000 U, where 1 U = 1 μGy m(2)/h in a...

journal_title：Medical physics

authors： Espinoza A,Beeksma B,Petasecca M,Fuduli I,Porumb C,Cutajar D,Corde S,Jackson M,Lerch ML,Rosenfeld AB

更新日期：2013-11-01 00:00:00

abstract：:Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tis...

journal_title：Medical physics

authors： Pogue BW,Paulsen KD,Samkoe KS,Elliott JT,Hasan T,Strong TV,Draney DR,Feldwisch J

更新日期：2016-06-01 00:00:00

abstract：:A new energy selective detector for dual energy computed radiography has been developed that combines many of the advantages of x-ray tube voltage switching and single exposure double screen detectors. The new active detector utilizes electro-optical modulation of the response of the storage phosphor screens to allow ...

journal_title：Medical physics

authors： Alvarez RE

更新日期：1996-10-01 00:00:00

abstract：:A multislit collimator was designed and fabricated for basic studies on microbeam radiation therapy (MRT) with an x-ray energy of about 100 keV. It consists of 30 slits that are 25 microm high, 30 mm wide, and 5 mm thick in the beam direction. The slits were made of 25 microm-thick polyimide sheets that were separated...

journal_title：Medical physics

authors： Ohno Y,Torikoshi M,Suzuki M,Umetani K,Imai Y,Uesugi K,Yagi N

更新日期：2008-07-01 00:00:00

abstract：:Purpose To investigate narrow, elongated magnetically focused proton beams and compare their properties with passively collimated beams using Monte Carlo simulation. METHODS:We performed Geant4 Monte Carlo simulations involving a single quadrapole focusing magnet, thereby creating a flattened beam with an elongated e...

journal_title：Medical physics

authors： McAuley G,Barnes S,Wroe A,Slater J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:In the practice code of dosimetry, humidity effect is assumed to be constant as far as the measurements are performed in the relative humidity (RH) range of (20-80)%; thus, the humidity effect can be ignored with a dose uncertainty of 0.15%. This assumption is based on the previous experimental results by Niate...

journal_title：Medical physics

authors： Sato Y,Shimizu M,Morishita Y,Sato M,Hoshina M

更新日期：2019-09-01 00:00:00

abstract：:An important aspect of heavy charged particle radiotherapy is its ability to localize dose to the target volume. Current techniques generally employ beam delivery schemes which use range modulated beams in which the Bragg peak is spread out over a range of depths. The range modulation is constant over the entire beam ...

journal_title：Medical physics

authors： Goitein M,Chen GT

更新日期：1983-11-01 00:00:00

abstract：:As a potentially important technology for medical x-ray computed tomography (CT), lambda tomography (LT) is to reconstruct a gradient-like image only from local projection data. Based on our recently derived exact fan-beam LT formula, [H. Y. Gu and G. Wang, Int. J. Biomed. Imaging 2006(1), 1-9 (2006)] here we propose ...

journal_title：Medical physics

authors： Yu H,Ye Y,Wang G

更新日期：2006-10-01 00:00:00

abstract：PURPOSE:A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system ...

journal_title：Medical physics

authors： Mendez I,Hartman V,Hudej R,Strojnik A,Casar B

更新日期：2013-01-01 00:00:00

abstract：OBJECTIVES:To evaluate the performance of RapidArc® (Eclipse 10.0.28) and SmartArc® (Pinnacle 9.0) radiotherapy plans for lung stereotactic body radiation therapy (SBRT) in terms of dosimetric plan quality, delivery efficiency, inhomogeneity corrections and accuracy of dose delivery using a custom-built heterogeneity i...

journal_title：Medical physics

authors： Fakir H,Hoover D,Chen JZ

更新日期：2012-07-01 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 commonly used Blunck and Leisegang electron energy-loss distribution falls off too rapidly with increasing energy loss. Also, for large thicknesses and/or low-Z media, where their distribution should approach Landau's, it normalizes to 0.92 rather than 1.0, it overestimates the number of very small energy-loss eve...

journal_title：Medical physics

authors： Weinhous MS,Nath R

更新日期：1984-05-01 00:00:00

abstract：PURPOSE:Elastography using computer tomography (CT) is a promising methodology that can provide patient-specific regional distributions of lung biomechanical properties. The purpose of this paper is to investigate the feasibility of performing elastography using simulated lower dose CT scans. METHODS:A cohort of eight...

journal_title：Medical physics

authors： Hasse K,Hsieh SS,O'Connell D,Stiehl B,Min Y,Neylon J,Low DA,Santhanam AP

更新日期：2020-08-01 00:00:00

abstract：:A tomographic attachment was designed and developed that attaches to our existing simulator. The film tomograms obtained with the aid of this device exhibit very low geometrical distortion and good contrast and resolution for the objects used in this investigation. In addition, our results to date show that adjacent a...

journal_title：Medical physics

authors： Kessaris ND,Harisiadis L

更新日期：1980-03-01 00:00:00