Dosimetry for radiocolloid therapy of cystic craniopharyngiomas.

abstract：:Different methods exist to determine the air kerma calibration factor of an ionization chamber for the spectrum of a 192Ir high-dose-rate (HDR) or pulsed-dose-rate (PDR) source. An analysis of two methods to obtain such a calibration factor was performed: (i) the method recommended by [Goetsch et al., Med. Phys. 18, 4...

journal_title：Medical physics

authors： van Dijk E,Kolkman-Deurloo IK,Damen PM

更新日期：2004-10-01 00:00:00

abstract：PURPOSE:The authors investigate performance of thin-film cadmium telluride (CdTe) in detecting high-energy (6 MV) x rays. The utilization of this material has become technologically feasible only in recent years due to significant development in large area photovoltaic applications. METHODS:The CdTe film is combined w...

journal_title：Medical physics

authors： Parsai EI,Shvydka D,Kang J

更新日期：2010-08-01 00:00:00

abstract：PURPOSE:To investigate the feasibility of implementing a novel approach for patient-specific QA of TomoDirect(TM) whole breast treatment. METHODS:The most currently used TomoTherapy DQA method, consisting in the verification of the 2D dose distribution in a coronal or sagittal plane of the Cheese Phantom by means of g...

journal_title：Medical physics

authors： Catuzzo P,Zenone F,Aimonetto S,Peruzzo A,Casanova Borca V,Pasquino M,Franco P,La Porta MR,Ricardi U,Tofani S

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:We investigated the feasibility of proton tomosynthesis as daily positioning of patients and compared the results with photon tomosynthesis as an alternative to conventional portal imaging or on-board cone-beam computed tomography. METHODS:Dedicated photon-like proton beam using the passively scattered proton ...

journal_title：Medical physics

authors： Min B,Kwak J,Lee J,Cho S,Park S,Yoo S,Chung K,Cho S,Lim Y,Shin D,Lee S,Kim J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To develop and validate a multivariate statistical method to optimize scanning parameters for material quantification in spectral x-rayimaging. METHODS:An optimization metric was constructed by extensively sampling the thickness space for the expected number of counts for m (two or three) materials. This resul...

journal_title：Medical physics

authors： Nik SJ,Thing RS,Watts R,Meyer J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Wide-angle free-air chambers (WAFACs) are used as primary standard measurement devices for establishing the air-kerma strength of low-energy, low-dose rate brachytherapy seeds. The National Research Council of Canada (NRC) is commissioning a primary standard wide-angle free-air chamber (NRC WAFAC) to serve the ...

journal_title：Medical physics

authors： Shen H,Culberson WS,Ross CK

更新日期：2016-07-01 00:00:00

abstract：:Many papers discussed the I value for water given by the ICRU, concluding that a value of about 80 +/- 2 eV instead of 67.2 eV would reproduce measured ion depth-dose curves. A change in the I value for water would have an effect on the stopping power and, hence, on the water-to-air stopping power ratio, which is impo...

journal_title：Medical physics

authors： Henkner K,Bassler N,Sobolevsky N,Jäkel O

更新日期：2009-04-01 00:00:00

abstract：PURPOSE:The local depth dose gradient and the displacement correction factor for Farmer-type ionization chambers are quantified for reference dosimetry at shallow depth in single-layer scanned proton fields. METHOD:Integrated radial profiles as a function of depth (IRPDs) measured at three proton therapy centers were ...

journal_title：Medical physics

authors： Palmans H,Medin J,Trnková P,Vatnitsky S

更新日期：2020-12-01 00:00:00

abstract：PURPOSE:To investigate the effect of energy (kVp) and filters (no filter, half Bowtie, and full Bowtie) on the dose response curves of the Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters (OSLDs) in CBCT dose fields. To measure surface and internal doses received during x-ray volume imager (...

journal_title：Medical physics

authors： Giaddui T,Cui Y,Galvin J,Yu Y,Xiao Y

更新日期：2013-06-01 00:00:00

abstract：PURPOSE:This study investigated the dosimetry performance of a linear fiber-optic coupled dosimeter with a sensitive element varying from 3 to 15 cm in length. The dosimeter is comprised of a tissue equivalent plastic scintillating fiber coupled to a photomultiplier tube (PMT). The sensitive element has a length repres...

journal_title：Medical physics

authors： Hoerner M,Hintenlang D

更新日期：2012-06-01 00:00:00

abstract：:Electron beam dosimetry at low monitor unit (MU) settings is important for dosimetric applications. Dose linearity, beam flatness, and beam energies were studied at low MU settings with various dose rates for different types of linear accelerators. It is observed that for the scattering foil units, the dose/MU is a sm...

journal_title：Medical physics

authors： Das IJ,Harrington JC,Akber SF,Tomer AF,Murray JC,Cheng CW

更新日期：1994-06-01 00:00:00

abstract：:An analytic expression is derived for the transmission of isotropic scattered radiation incident upon an ideal parallel grid. It is found that the expression for the transmission usually found in the literature overestimates the transmission by approximately a factor of two. ...

journal_title：Medical physics

authors： Siddon RL

更新日期：1981-11-01 00:00:00

abstract：:A method is described for obtaining S values between a tumor and its host organ for use with the MIRD formalism. It applies the point-source specific absorbed fractions for an infinite water medium, tabulated by Berger, to a rectangular solid of arbitrary dimensions which contains a rectangular tumor of arbitrary dime...

journal_title：Medical physics

authors： Stinchcomb TG,Durham JS,Fisher DR

更新日期：1991-05-01 00:00:00

abstract：PURPOSE:The spatial and temporal tracking performance of a commercially available 3D optical surface imaging system is evaluated for its potential use in frameless stereotactic radiosurgery head tracking applications. METHODS:Both 3D surface and infrared (IR) marker tracking were performed simultaneously on a head pha...

journal_title：Medical physics

authors： Wiersma RD,Tomarken SL,Grelewicz Z,Belcher AH,Kang H

更新日期：2013-11-01 00:00:00

abstract：:A study of the objective imaging characteristics of a new asymmetric screen-film system is presented herein. The system is characterized by high x-ray absorption asymmetric screens, and a low-noise, high-contrast asymmetric film having near-zero crossover. Comparisons are made with the imaging characteristics of two w...

journal_title：Medical physics

authors： Van Metter R,Dickerson R

更新日期：1994-09-01 00:00:00

abstract：:A series of experiments has been carried out in order to characterize a miniannular phased array applicator prior to possible clinical implementation. The energy deposition patterns over the frequency range of 100 to 200 MHz were determined in several human limb models of different complexities by measuring the electr...

journal_title：Medical physics

authors： Guerquin-Kern JL,Hagmann MJ,Levin RL

更新日期：1987-07-01 00:00:00

abstract：PURPOSE:To characterize the radiation dose and three-dimensional (3D) imaging performance of a recently developed mobile, isocentric C-arm equipped with a flat-panel detector (FPD) for intraoperative cone-beam computed tomography (CBCT) (Cios Spin 3D, Siemens Healthineers) and to identify potential improvements in 3D i...

journal_title：Medical physics

authors： Sheth NM,De Silva T,Uneri A,Ketcha M,Han R,Vijayan R,Osgood GM,Siewerdsen JH

更新日期：2020-03-01 00:00:00

abstract：:The measurement of output factors for small fields is challenging and can lead to large dose errors in patient treatments if corrections for detector size and scatter from high-Z material are not applied. Due to its high spatial resolution and near tissue equivalence, GAFCHROMIC® film potentially provides a correction...

journal_title：Medical physics

authors： Vandervoort E,La Russa D,Ploquin N,Kadir IAE,Szanto J

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:Proton computed tomography (pCT) will enable accurate prediction of proton and ion range in a patient while providing the benefit of lower radiation exposure than in x-ray CT. The accuracy of the range prediction is essential for treatment planning in proton or ion therapy and depends upon the detector used to ...

journal_title：Medical physics

authors： Bashkirov VA,Schulte RW,Hurley RF,Johnson RP,Sadrozinski HF,Zatserklyaniy A,Plautz T,Giacometti V

更新日期：2016-02-01 00:00:00

abstract：:A doorless entry system has been designed for use in high-energy radiation therapy rooms. The doorless entry improves patient access, safety and throughput, increases the physical safety for the radiation therapists, and avoids the significant cost of heavy shielding doors. The design meets concerns relating to radiat...

journal_title：Medical physics

authors： Dawson DJ,Wissing WW,Tonks RE

更新日期：1998-02-01 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：PURPOSE:The research is to develop a novel CNN-based adversarial deep learning method to improve and expedite the multi-organ semantic segmentation of CT images and to generate accurate contours on pelvic CT images. METHODS:Planning CT and structure datasets for 120 patients with intact prostate cancer were retrospect...

journal_title：Medical physics

authors： Zhang Z,Zhao T,Gay H,Zhang W,Sun B

更新日期：2020-11-05 00:00:00

abstract：PURPOSE:This article presents a new reconstruction method for 3D imaging using a multiple 360 degrees circular orbit cone beam CT system, specifically a way to combine 3D volumes reconstructed with each orbit. The main goal is to improve the noise performance in the combined image while avoiding cone beam artifacts. M...

journal_title：Medical physics

authors： Baek J,Pelc NJ

更新日期：2010-10-01 00:00:00

abstract：:The performance of an indirect-detection, active matrix flat-panel imager (FPI) at diagnostic energies is reported in terms of measured and theoretical signal size, noise power spectrum (NPS), and detective quantum efficiency (DQE). Based upon a 1536 x 1920 pixel, 127 microns pitch array of a-Si:H thin-film transistor...

journal_title：Medical physics

authors： Siewerdsen JH,Antonuk LE,el-Mohri Y,Yorkston J,Huang W,Cunningham IA

更新日期：1998-05-01 00:00:00

abstract：:This is an introductory tutorial to the field of microdosimetry. Following a brief historical outline, we review the physics of experimental and theoretical microdosimetry and the application of microdosimetry to radiation biology within the so-called "site" approximation. Modern interpretations of microdosimetry that...

journal_title：Medical physics

authors： Rossi HH,Zaider M

更新日期：1991-11-01 00:00:00

abstract：PURPOSE:The authors are developing a system for calibrated breast density measurements using full field digital mammography (FFDM). Breast tissue equivalent (BTE) phantom images are used to establish baseline (BL) calibration curves at time zero. For a given FFDM unit, the full BL dataset is comprised of approximately ...

journal_title：Medical physics

authors： Lu B,Smallwood AM,Sellers TA,Drukteinis JS,Heine JJ,Fowler EE

更新日期：2015-02-01 00:00:00

abstract：PURPOSE:Metal artifact reduction (MAR) is a major problem and a challenging issue in x-ray computed tomography (CT) examinations. Iterative reconstruction from sinograms unaffected by metals shows promising potential in detail recovery. This reconstruction has been the subject of much research in recent years. However,...

journal_title：Medical physics

authors： Zhang H,Wang L,Li L,Cai A,Hu G,Yan B

更新日期：2016-06-01 00:00:00

abstract：PURPOSE:The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different...

journal_title：Medical physics

authors： Schmitz T,Bassler N,Blaickner M,Ziegner M,Hsiao MC,Liu YH,Koivunoro H,Auterinen I,Serén T,Kotiluoto P,Palmans H,Sharpe P,Langguth P,Hampel G

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:Optically stimulated luminescence (OSL) dosimetry has been recently introduced in radiation therapy as a potential alternative to the thermoluminescent dosimeter (TLD) system. The aim of this study was to investigate the feasibility of using OSL point dosimeters in the energy range used in diagnostic imaging. ...

journal_title：Medical physics

authors： Al-Senan RM,Hatab MR

更新日期：2011-07-01 00:00:00

abstract：:An anthropomorphic 1H MRS head phantom has been developed which mimics the in vivo structure, metabolite concentrations, and relaxation times (for both water and metabolites) of human brain tissue. Different brain regions and two tumor types, fluid-containing ventricles, and air-filled sinus, and subcutaneous fat are ...

journal_title：Medical physics

authors： Rice JR,Milbrandt RH,Madsen EL,Frank GR,Boote EJ,Blechinger JC

更新日期：1998-07-01 00:00:00