A simple model for examining issues in radiotherapy optimization.

abstract：:The Anisotropic Analytical Algorithm (AAA) of the Varian Eclipse treatment planning system calculates absolute dose for a variety of beam settings including those with an enhanced dynamic wedge (EDW). This algorithm has gone through a number of version updates since it was first released in July 2005. Previous version...

journal_title：Medical physics

authors： Salomons G,Kerr A,Mei X,Patel D

更新日期：2008-07-01 00:00:00

abstract：:The validity of conclusions drawn from multi-institutional radiotherapy studies is dependent upon the degree to which participating hospitals adhere to study requirements. A major effort undertaken by the Quality Assurance Review Center (QARC) assesses whether or not patient data which are deemed evaluable actually co...

journal_title：Medical physics

authors： Reinstein LE,McShan D,Glicksman AS

更新日期：1982-03-01 00:00:00

abstract：PURPOSE:Talbot-Lau x-ray interferometry provides information about the scattering and refractive properties of an object - in addition to the object's attenuation features. Until recently, this method was ineligible for imaging human-sized objects as it is challenging to adapt Talbot-Lau interferometers (TLIs) to the r...

journal_title：Medical physics

authors： Hauke C,Bartl P,Leghissa M,Ritschl L,Sutter SM,Weber T,Zeidler J,Freudenberger J,Mertelmeier T,Radicke M,Michel T,Anton G,Meinel FG,Baehr A,Auweter S,Bondesson D,Gaass T,Dinkel J,Reiser M,Hellbach K

更新日期：2018-06-01 00:00:00

abstract：:Two acrylic cube phantoms have been constructed for BNCT applications that allow the depth distribution of neutrons to be measured with miniature 10BF3 detectors in 0.5-cm steps beginning at 1-cm depth. Sizes and weights of the cubes are 14 cm, 3.230 kg, and 11 cm, 1.567 kg. Tests were made with the epithermal neutron...

journal_title：Medical physics

authors： Alburger DE,Raparia D,Zucker MS

更新日期：1998-09-01 00:00:00

abstract：:High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classificatio...

journal_title：Medical physics

authors： Li L,Zheng Y,Zhang L,Clark RA

更新日期：2001-02-01 00:00:00

abstract：:The purpose of this paper is to develop a method that reduces the number of segments for intensity modulated arc therapy (IMAT) and intensity modulated radiotherapy (IMRT) for concave target volumes (TV). The aim was to utilize no more than two intensity levels per organ at risk (OAR) and to derive both optimal segmen...

journal_title：Medical physics

authors： Bratengeier K

更新日期：2005-03-01 00:00:00

abstract：PURPOSE:The Alvarez-Macovski method extracts the x-ray energy-dependent information by expanding the attenuation coefficient as a linear combination of functions of energy multiplied by basis set coefficients. Since the basis functions are known a priori, the coefficients represent all the energy-dependent information....

journal_title：Medical physics

authors： Alvarez RE

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:Secondary particles produced in the collision of protons with beam modifiers are of concern in proton therapy. Nevertheless, secondary radiation can provide information on the dosimetric parameters through its dependency on the modulating accessories (range shifter and range modulating wheel). Relatively little...

journal_title：Medical physics

authors： Carnicer A,Letellier V,Rucka G,Angellier G,Sauerwein W,Herault J

更新日期：2012-12-01 00:00:00

abstract：PURPOSE:Mega-voltage cone-beam CT (MVCBCT) imaging can be used to monitor changes in neck flexion and calculate the true spinal cord dose during radiotherapy. To sum the dose over multiple fractions and compare with the planned dose requires deformable image registration. This study investigates the accuracy of deforma...

journal_title：Medical physics

authors： Ueda U,Chen J,Kirby N,Quivey J,Yom S,Pouliot J

更新日期：2012-06-01 00:00:00

abstract：:The physical characteristics of a clinical charge coupled device (CCD)-based imager (Senovision, GE Medical Systems, Milwaukee, WI) for small-field digital mammography have been investigated. The imager employs a MinR 2000 (Eastman Kodak Company, Rochester, NY) scintillator coupled by a 1:1 optical fiber to a front-il...

journal_title：Medical physics

authors： Vedantham S,Karellas A,Suryanarayanan S,Levis I,Sayag M,Kleehammer R,Heidsieck R,D'Orsi CJ

更新日期：2000-08-01 00:00:00

abstract：:Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. ...

journal_title：Medical physics

authors： Walters BR,Ding GX,Kramer R,Kawrakow I

更新日期：2009-07-01 00:00:00

abstract：PURPOSE:To evaluate a simple, semi-automated lung mass estimation method on CT scans from a variety of acquisition techniques for mass correction of MIRD dose estimates. METHODS:CT scans from ten patients undergoing stereotactic body radiation therapy treatment planning on a GE DST PET/CT scanner were analyzed retrosp...

journal_title：Medical physics

authors： Busse N,Erwin W,Pan T

更新日期：2012-06-01 00:00:00

abstract：:Dose to the total body from induced radiation resulting from primary exposure to radiotherapeutic beams is not detailed in routine treatment planning though this information is potentially important for better estimates of health risks including secondary cancers. This information can also allow better management of p...

journal_title：Medical physics

authors： Difilippo F,Papiez L,Moskvin V,Peplow D,DesRosiers C,Johnson J,Timmerman R,Randall M,Lillie R

更新日期：2003-10-01 00:00:00

abstract：PURPOSE:Colon cancer is a major public health problem due to its high disease rate and death toll worldwide. The use of FTIR microscopy in the field of cancer diagnosis has become attractive over the past 20 years. In the present study, the authors investigated the potential of FTIR microscopy to define spectral change...

journal_title：Medical physics

authors： Zwielly A,Mordechai S,Sinielnikov I,Salman A,Bogomolny E,Argov S

更新日期：2010-03-01 00:00:00

abstract：:We are developing an automated stereo spot mammography technique for improved imaging of suspicious dense regions within digital mammograms. The technique entails the acquisition of a full-field digital mammogram, automated detection of a suspicious dense region within that mammogram by a computer aided detection (CAD...

journal_title：Medical physics

authors： Goodsitt MM,Chan HP,Lydick JT,Gandra CR,Chen NG,Helvie MA,Bailey JE,Roubidoux MA,Paramagul C,Blane CE,Sahiner B,Petrick NA

更新日期：2004-06-01 00:00:00

abstract：:Previous ultrasound tomography work conducted by our group showed a direct correlation between measured sound speed and physical density in vitro, and increased in vivo sound speed with increasing mammographic density, a known risk factor for breast cancer. Building on these empirical results, the purpose of this work...

journal_title：Medical physics

authors： Glide-Hurst CK,Duric N,Littrup P

更新日期：2008-09-01 00:00:00

abstract：:This paper presents a numerical investigation of the effective point of measurement of thimble ionization chambers in megavoltage photon beams using Monte Carlo simulations with the EGSNRC system. It is shown that the effective point of measurement for relative photon beam dosimetry depends on every detail of the cham...

journal_title：Medical physics

authors： Kawrakow I

更新日期：2006-06-01 00:00:00

abstract：PURPOSE:To correct for the deviations of the detector response when typical radiation detectors are used under non-reference conditions, factor kNR was calculated from the known energy dependence of the detector response at photon energies from 10 keV upwards and from clinical photon spectra within a large water phanto...

journal_title：Medical physics

authors： Chofor N,Poppe B,Harder D

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Phase contrast imaging, particularly of the breast, is being actively investigated. The purpose of this work is to investigate the x-ray phase contrast properties of breast tissues and commonly used breast tissue substitutes or phantom materials with an aim of determining the phantom materials best representati...

journal_title：Medical physics

authors： Vedantham S,Karellas A

更新日期：2013-04-01 00:00:00

abstract：:Age-related macular degeneration (AMD) is a leading cause for vision loss for people over the age of 65 in the United States and a major health problem worldwide. Research for new treatments of the wet form of the disease using kilovoltage stereotactic radiosurgery is currently underway at Oraya Therapeutics, Inc. In ...

journal_title：Medical physics

authors： Hanlon J,Lee C,Chell E,Gertner M,Hansen S,Howell RW,Bolch WE

更新日期：2009-08-01 00:00:00

abstract：PURPOSE:Cone-beam computed tomography (CBCT) is an increasingly utilized imaging modality for the diagnosis and treatment planning of the patients with craniomaxillofacial (CMF) deformities. Accurate segmentation of CBCT image is an essential step to generate three-dimensional (3D) models for the diagnosis and treatmen...

journal_title：Medical physics

authors： Wang L,Chen KC,Gao Y,Shi F,Liao S,Li G,Shen SG,Yan J,Lee PK,Chow B,Liu NX,Xia JJ,Shen D

更新日期：2014-04-01 00:00:00

abstract：PURPOSE:The thermoluminescence dosimeter (TLD) has desirable features including low cost, reusability, small size, and relatively low energy dependence. However, the commonly available poly-crystal TLDs (e.g., TLD-100) exhibit high interdetector variability that requires individual calibration for high detection accura...

journal_title：Medical physics

authors： Shang D,Gu W,Landers A,Woods K,Yu V,Neph R,Tenn S,Sheng K

更新日期：2020-01-01 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 assess the image quality, scatter, and leakage radiation of an integrated magnetic resonance linear accelerator (MR-LINAC or MRL) system. METHODS:A large American College of Radiology (ACR) magnetic resonance imaging (MRI) accreditation phantom was used to evaluate the MRI capabilities of the integrated MRL...

journal_title：Medical physics

authors： Wang J,Yung J,Kadbi M,Hwang K,Ding Y,Ibbott GS

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:To achieve more translatable preclinical research results, small animal irradiation needs to more closely simulate human radiotherapy. Although the clinical gold standard is intensity-modulated radiation therapy (IMRT), the direct translation of this method for small animals is impractical. In this study we des...

journal_title：Medical physics

authors： Woods K,Nguyen D,Neph R,Ruan D,O'Connor D,Sheng K

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:The goal of this work is to propose a new multichannel method correcting for systematic thickness disturbances and to evaluate its precision in relevant radiation dosimetry applications. METHODS:The eigencolor ratio technique is introduced and theoretically developed to provide a method correcting for thicknes...

journal_title：Medical physics

authors： Bouchard H,Billas I,Subie A,Duane S

更新日期：2021-02-01 00:00:00

abstract：:In the present investigation, the necessary tests for implementing a quality assurance program for a commercial treatment planning system (TPS), recently installed at Sao Paulo University School of Medicine Clinicas Hospital-Brazil, was established and performed in accordance with the new IAEA publication TRS 430, and...

journal_title：Medical physics

authors： Camargo PR,Rodrigues LN,Furnari L,Rubo RA

更新日期：2007-07-01 00:00:00

abstract：:A systems analysis of reduced dose mammography with scatter removal has quantitatively specified the relationships between the several parameters in mammography systems. While the results are only preliminary in the sense that they need to be proven experimentally, they do seem to provide a good feel for the nature of...

journal_title：Medical physics

authors： Muntz EP

更新日期：1979-03-01 00:00:00

abstract：PURPOSE:The nonlocal influence from distant magnetization will affect the magnetic field at a voxel in question. Existing reports on BOLD simulation only consider vasculature inside a single voxel, thus omitting the contribution from the surrounding regions. In this article, the authors study the effect of the surround...

journal_title：Medical physics

authors： Chen Z,Caprihan A,Calhoun V

更新日期：2010-04-01 00:00:00

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