An automated dosimetry data-acquisition and analysis system at the LAMPF pion therapy facility.

abstract：:A method to significantly reduce the exposure area product in fluoroscopy using a pre-patient region-of-interest (ROI) attenuator is presented. The attenuator has a thin central region and a gradually increasing thickness away from the center. It is shown that the unwanted brightening artifact caused by the attenuator...

journal_title：Medical physics

authors： Robert N,Komljenovic PT,Rowlands JA

更新日期：2002-05-01 00:00:00

abstract：PURPOSE:The feasibility of magnetic resonance image (MRI)-based proton therapy is based, among several other factors, on the implementation of appropriate extensions on current dose calculation methods. This work aims to develop a pencil beam algorithm (PBA) for dose calculation of proton beams within magnetic field re...

journal_title：Medical physics

authors： Padilla-Cabal F,Georg D,Fuchs H

更新日期：2018-05-01 00:00:00

abstract：PURPOSE:Radioembolization with yttrium-90 microspheres may be optimized with patient-specific pretherapy treatment planning. Dose verification and validation of treatment planning methods require quantitative imaging of the post-therapy distribution of yttrium-90 (Y-90). Methods for quantitative imaging of Y-90 using b...

journal_title：Medical physics

authors： Yue J,Mauxion T,Reyes DK,Lodge MA,Hobbs RF,Rong X,Dong Y,Herman JM,Wahl RL,Geschwind JH,Frey EC

更新日期：2016-10-01 00:00:00

abstract：PURPOSE:The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil ...

journal_title：Medical physics

authors： Chen CC,Chang C,Moyers MF,Gao M,Mah D

更新日期：2016-02-01 00:00:00

abstract：PURPOSE:Removal of the linear accelerator (linac) flattening filter enables a high rate of dose deposition with reduced treatment time. When used for megavoltage imaging, an unflat beam has reduced primary beam scatter resulting in sharper images. In fluoroscopic imaging mode, the unflat beam has higher photon count pe...

journal_title：Medical physics

authors： Christensen JD,Kirichenko A,Gayou O

更新日期：2013-08-01 00:00:00

abstract：:The measurement of the radioactivity administered to the patient is one of the major components of 90Y microsphere liver brachytherapy. The activity of 90Y microspheres in a glass delivery vial was measured in a dose calibrator. The calibration value to use for 90Y in the dose calibrator was verified using an activity...

journal_title：Medical physics

authors： Dezarn WA,Kennedy AS

更新日期：2007-06-01 00:00:00

abstract：PURPOSE:To investigate dosimetry for ocular brachytherapy for a range of eye plaque models containing(103)Pd, (125)I, or (131)Cs seeds with model-based dose calculations. METHODS:Five representative plaque models are developed based on a literature review and are compared to the standardized COMS plaque, including pla...

journal_title：Medical physics

authors： Lesperance M,Martinov M,Thomson RM

更新日期：2014-03-01 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:To study and compare the dose response curves of the new GafChromic EBT3 film for megavoltage and kilovoltage x-ray beams, with different spatial resolution. METHODS:Two sets of EBT3 films (lot#A101711-02) were exposed to each x-ray beam (6MV, 15MV and 50kV) at 8 dose values (50-3200cGy). The megavoltage beams...

journal_title：Medical physics

authors： Chiu-Tsao S,Massillon-Jl G,Domingo-Muñoz I,Chan M

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:In this work, the fabrication, operation, and evaluation of a probe-format graphite calorimeter - herein referred to as Aerrow - as an absolute clinical dosimeter of high-energy photon beams while in the presence of a B = 1.5 T magnetic field is described. Comparable to a cylindrical ionization chamber (IC) in ...

journal_title：Medical physics

authors： Renaud J,Sarfehnia A,Bancheri J,Seuntjens J

更新日期：2020-03-01 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：:The scattered-photon part of pencil-beam dose kernels for high-energy x-ray beams can be derived experimentally by differentiating the broad-beam scatter-to-primary dose ratio as a function of radius. Formally, this requires a uniform and parallel beam, and the procedure is complicated by the nonideal, actual beam con...

journal_title：Medical physics

authors： Ceberg CP,Bjärngard BE

更新日期：1996-09-01 00:00:00

abstract：PURPOSE:The main objective of this work was to design a comprehensive dosimetry package that would keep all aspects of internal dose calculation within the framework of a single software environment and that would be applicable for a variety of dose calculation approaches. METHODS:Our MATLAB-based graphical user inter...

journal_title：Medical physics

authors： Grimes J,Uribe C,Celler A

更新日期：2013-07-01 00:00:00

abstract：PURPOSE:In Stereotactic body radiation therapy (SBRT) higher dose per fraction is delivered to patients and thus the need for an accurate dose computation is further elevated. However under such conditions of small field geometries, the electronic equilibrium can be lost, making it challenging for the dose-calculation ...

journal_title：Medical physics

authors： Shosha M,Deiab N,Eldib A,Tohamy K

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To provide a cascaded-systems framework based on the noise-power spectrum (NPS), modulation transfer function (MTF), and noise-equivalent number of quanta (NEQ) for quantitative evaluation of differential phase-contrast imaging (Talbot interferometry) in relation to conventional absorption contrast under equal-...

journal_title：Medical physics

authors： Fredenberg E,Danielsson M,Stayman JW,Siewerdsen JH,Aslund M

更新日期：2012-09-01 00:00:00

abstract：:Modern linear accelerators contain multiple isocentres, defined by the mechanical motions of gantry, collimator and table. Isocentre localization for these motions has been performed using film and manual evaluations which have difficulty in relating the individual motions. To address these limitations, we have develo...

journal_title：Medical physics

authors： Heaton R,Smale J,Norrlinger B,Wang Y,van Prooijen M,Islam M

更新日期：2008-07-01 00:00:00

abstract：:Our purpose in this paper is to present an in vivo dosimetry program designed both for measuring the rectal dose and for avoiding misadministrations in gynecological intracavitary implants. A device containing an energy compensated diode was specially designed for these measurements. Our calibration procedure as well ...

journal_title：Medical physics

authors： Alecu R,Alecu M

更新日期：1999-05-01 00:00:00

abstract：PURPOSE:Intensity-Modulated Radiation Therapy (IMRT), including its variations (including IMRT, Volumetric Arc Therapy (VMAT), and Tomotherapy), is a widely used and critically important technology for cancer treatment. It is a knowledge-intensive technology due not only to its own technical complexity, but also to the...

journal_title：Medical physics

authors： Ge Y,Wu QJ

更新日期：2019-06-01 00:00:00

abstract：:Positron emission mammography (PEM) is a new, specialized imaging modality utilizing PET radiopharmaceuticals to detect breast cancer. The capabilities and limitations of PEM in detecting breast tumors were investigated with a series of phantom experiments. The PEM imager was mounted on a standard Lorad biopsy table (...

journal_title：Medical physics

authors： Raylman RR,Majewski S,Wojcik R,Weisenberger AG,Kross B,Popov V,Bishop HA

更新日期：2000-08-01 00:00:00

abstract：PURPOSE:Upgrade and benchmarking of a research 4D treatment planning system (4DTPS) suitable for realistic patient treatment planning and treatment simulations taking into account specific requirements for scanned ion beam therapy, i.e., modeling of dose heterogeneities due to interplay effects and range changes caused...

journal_title：Medical physics

authors： Richter D,Schwarzkopf A,Trautmann J,Krämer M,Durante M,Jäkel O,Bert C

更新日期：2013-05-01 00:00:00

abstract：:Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal p...

journal_title：Medical physics

authors： Tward DJ,Siewerdsen JH,Daly MJ,Richard S,Moseley DJ,Jaffray DA,Paul NS

更新日期：2007-11-01 00:00:00

abstract：:Manganese (Mn) is an essential nutrient for growth and development. Unfortunately, overexposure can lead to neurological damage, which is manifested as a movement disorder marked by tremors. Preclinical symptoms have been found in populations occupationally exposed to the element, and it is suggested that in late stag...

journal_title：Medical physics

authors： Arnold ML,McNeill FE,Stronach IM,Pejovic-Milic A,Chettle DR,Waker A

更新日期：2002-11-01 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:Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most o...

journal_title：Medical physics

authors： Yoriyaz H,Moralles M,Siqueira Pde T,Guimarães Cda C,Cintra FB,dos Santos A

更新日期：2009-11-01 00:00:00

abstract：:We are evaluating the usefulness of stereomammography in improving breast cancer diagnosis. One area that we are investigating is whether the improved depth perception associated with stereomammography might be significantly enhanced with the use of a virtual 3D cursor. A study was performed to evaluate the accuracy o...

journal_title：Medical physics

authors： Goodsitt MM,Chan HP,Hadjiiski L

更新日期：2000-06-01 00:00:00

abstract：:One of the key components in modern LINAC room shielding design is the amount of 90 degrees head leakage radiation levels. With the general clinical acceptance of intensity-modulated radiation therapy (IMRT) technique, accurate knowledge of this quantity has become even more important. Measurement of 90 degrees head l...

journal_title：Medical physics

authors： Li Z,Mutic S,Low D

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:The aim of in vivo skin dosimetry was to measure the absorbed dose to the skin during radiotherapy, when treatment planning calculations cannot be relied on. It is of particularly importance in hypo-fractionated stereotactic modalities, where excessive dose can lead to severe skin toxicity. Currently, commercia...

journal_title：Medical physics

authors： Vicoroski N,Espinoza A,Duncan M,Oborn BM,Carolan M,Metcalfe P,Menichelli D,Perevertaylo VL,Lerch MLF,Rosenfeld AB,Petasecca M

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:The feasibility of intensity modulated brachytherapy (IMBT) to improve dose conformity for irregularly shaped targets has been previously investigated by researchers by means of using partially shielded sources. However, partial shielding does not fully explore the potential of IMBT. The goal of this study is t...

journal_title：Medical physics

authors： Shi C,Guo B,Cheng CY,Esquivel C,Eng T,Papanikolaou N

更新日期：2010-07-01 00:00:00

abstract：PURPOSE:Recently, brain tumor segmentation has made important progress. However, the quality of manual labels plays an important role in the performance, while in practice, it could vary greatly and in turn could substantially mislead the learning process and decrease the accuracy. We need to design a mechanism to comb...

journal_title：Medical physics

authors： Cheng G,Ji H,He L

更新日期：2020-09-24 00:00:00

abstract：PURPOSE:Atherosclerosis of peripheral cerebral arteries can lead to stroke either by stenosis formation or plaque rupture. This pathology is initiated by the alteration of arterial wall mechanical properties shown to be assessable by ultrasound elastography. Recently, noninvasive vascular elastography (NIVE) was introd...

journal_title：Medical physics

authors： Mercure E,Deprez JF,Fromageau J,Basset O,Soulez G,Cloutier G,Maurice RL

更新日期：2011-02-01 00:00:00