Comparison of organ-at-risk sparing and plan robustness for spot-scanning proton therapy and volumetric modulated arc photon therapy in head-and-neck cancer.

abstract：PURPOSE:Carpal tunnel syndrome (CTS) is the common entrapment neuropathy that occurs due to compression of the median nerve at the wrist. Ultrasound images have been used to highlight anatomical variants of the median nerve, and CTS is thought to be associated to enlargement of the cross-sectional area (CSA) of the med...

journal_title：Medical physics

authors： Liao YY,Wu CC,Kuo TT,Chen JP,Hsu YW,Yeh CK

更新日期：2012-12-01 00:00:00

abstract：BACKGROUND AND PURPOSE:Differential baseline shifts between primary tumor and involved lymph nodes in locally advanced lung cancer patients compromise the accuracy of radiotherapy. The purpose of this study was to evaluate the performance of an average anatomy model (AAM) derived from repeat imaging and deformable regi...

journal_title：Medical physics

authors： Abdoli M,Van Kranen SR,Stankovic U,Rossi MMG,Belderbos JSA,Sonke JJ

更新日期：2017-07-01 00:00:00

abstract：PURPOSE:A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. METHODS:A total of 300 patients receiving lung SBRT ...

journal_title：Medical physics

authors： Woerner A,Roeske JC,Harkenrider MM,Fan J,Aydogan B,Koshy M,Laureckas R,Vali F,Campana M,Surucu M

更新日期：2015-08-01 00:00:00

abstract：:Deionized water is commonly used to couple microwave applicators to the patient surface in the administration of local hyperthermia. Profiles of the specific absorption rate (SAR) at 1-cm depth show that deionized water coupling significantly distorts the SAR distributions of the Clini-Therm 915-MHz 10 X 10 and 15 X 1...

journal_title：Medical physics

authors： Waterman FM,Nerlinger RE

更新日期：1986-05-01 00:00:00

abstract：:We have studied the effect of real-time optical image processing (OIP) in an image intensifier/television (II-TV) radiographic imaging system by using a liquid-crystal display (LCD) placed between the II and the TV camera. The LCD compresses the dynamic range of the transmitted image by modulating the spatial distribu...

journal_title：Medical physics

authors： Lam KL,Chan HP,Doi K

更新日期：1988-11-01 00:00:00

abstract：:In order to understand the role of water desorption, i.e., the opposite of water adsorption, in optical clearing of biological tissue created by the application of hyperosmotic agents, dynamics of water loss in fresh porcine muscle tissue administrated with glycerol or ethylene glycol was investigated with the near-in...

journal_title：Medical physics

authors： Xu X,Wang RK

更新日期：2003-06-01 00:00:00

abstract：:This paper deals with methods of reducing the total time required to acquire the projection data for a set of contiguous computed tomography (CT) images. Normally during the acquisition of a set of slices, the patient is held stationary during data collection and translated to the next axial location during an intersc...

journal_title：Medical physics

authors： Crawford CR,King KF

更新日期：1990-11-01 00:00:00

abstract：PURPOSE:By means of Monte Carlo (MC) simulations and indirect measurements, we have evaluated the maximum dose rates achievable with conventional x-ray tubes and related them to FLASH therapy dose rates of >40 Gy/s. METHODS:Monte Carlo models of two 160 kV x-ray tubes, the 3-kW MXR-160/22 and the 6-kW MXR-165, were bu...

journal_title：Medical physics

authors： Bazalova-Carter M,Esplen N

更新日期：2019-12-01 00:00:00

abstract：PURPOSE:The purpose of this study was to investigate the impact of transverse magnetic fields on the dose response of a radiophotoluminescent glass dosimeter (RGD) in megavoltage photon beams. METHODS:The RGD relative response (i.e., RGD dose per absorbed dose to water at the midpoint of the detector in the absence of...

journal_title：Medical physics

authors： Ito S,Araki F,Ohno T

更新日期：2020-04-01 00:00:00

abstract：PURPOSE:Onboard imaging-currently performed primarily by x-ray transmission modalities-is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single pho...

journal_title：Medical physics

authors： Bowsher J,Yan S,Roper J,Giles W,Yin FF

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:Myocardial infarct (MI) may consist of an infarct core (IC) and a heterogeneous, semi-viable border zone (BZ). Patients with chronic MI in the left ventricular (LV) myocardium are at increased risk of developing ventricular arrhythmias, and may therefore qualify for implantable cardioverter defibrillator (ICD) ...

journal_title：Medical physics

authors： Farrag NA,Ramanan V,Wright GA,Ukwatta E

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:To report on significant dose enhancement effects caused by magnetic fields aligned parallel to 6 MV photon beam radiotherapy of small lung tumors. Findings are applicable to future inline MRI-guided radiotherapy systems. METHODS:A total of eight clinical lung tumor cases were recalculated using Monte Carlo me...

journal_title：Medical physics

authors： Oborn BM,Ge Y,Hardcastle N,Metcalfe PE,Keall PJ

更新日期：2016-01-01 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：PURPOSE:To compare and evaluate intensity-based registration methods for computation of serial x-ray mammogram correspondence. METHODS:X-ray mammograms were simulated from MRIs of 20 women using finite element methods for modeling breast compressions and employing a MRI/x-ray appearance change model. The parameter con...

journal_title：Medical physics

authors： Pinto Pereira SM,Hipwell JH,McCormack VA,Tanner C,Moss SM,Wilkinson LS,Khoo LA,Pagliari C,Skippage PL,Kliger CJ,Hawkes DJ,Silva IM

更新日期：2010-09-01 00:00:00

abstract：:The purpose of this work is to calculate the dose perturbations due to the presence of iodine contrast media in catheter-based intravascular brachytherapy (IVBT). The EGSnrc Monte Carlo system was used to perform the calculation for the two most commonly used beta and gamma sources (90Sr and 192Ir as well as for a var...

journal_title：Medical physics

authors： Li XA

更新日期：2001-05-01 00:00:00

abstract：:Most detectors in current positron emission tomography (PET) scanners and prototypes use lutetium oxyorthosilicate (LSO) or lutetium yttrium oxyorthosilicate (LYSO) scintillators. The aim of this work is to provide a complete set of background energy spectra, due to the scintillator intrinsic radioactivity, for a wide...

journal_title：Medical physics

authors： Domínguez-Jiménez DY,Alva-Sánchez H

更新日期：2021-01-21 00:00:00

abstract：PURPOSE:High-dose-rate brachytherapy (HDR-BT) is a treatment option for malignant skin diseases compared to external beam radiation therapy, HDR-BT provides improved target coverage, better organ sparing, and has comparable treatment times. This is especially true for large clinical targets with complex topologies. To ...

journal_title：Medical physics

authors： Guthier CV,Devlin PM,Harris TC,O'Farrell DA,Cormack RA,Buzurovic I

更新日期：2020-03-01 00:00:00

abstract：:A new rubber band straightening transform (RBST) is introduced for characterization of mammographic masses as malignant or benign. The RBST transforms a band of pixels surrounding a segmented mass onto the Cartesian plane (the RBST image). The border of a mammographic mass appears approximately as a horizontal line, a...

journal_title：Medical physics

authors： Sahiner B,Chan HP,Petrick N,Helvie MA,Goodsitt MM

更新日期：1998-04-01 00:00:00

abstract：PURPOSE:Repeated brain MRI scans are performed in many clinical scenarios, such as follow up of patients with tumors and therapy response assessment. In this paper, the authors show an approach to utilize former scans of the patient for the acceleration of repeated MRI scans. METHODS:The proposed approach utilizes the...

journal_title：Medical physics

authors： Weizman L,Eldar YC,Ben Bashat D

更新日期：2015-09-01 00:00:00

abstract：:A computerized scheme is being developed for the detection of masses in digital mammograms. Based on the deviation from the normal architectural symmetry of the right and left breasts, a bilateral subtraction technique is used to enhance the conspicuity of possible masses. The scheme employs two pairs of conventional ...

journal_title：Medical physics

authors： Yin FF,Giger ML,Doi K,Metz CE,Vyborny CJ,Schmidt RA

更新日期：1991-09-01 00:00:00

abstract：:Treatment simulation is usually performed with a conventional simulator using kV X-rays or with a computed tomography (CT) simulator before the treatment course begins. The purpose is to verify patient setup under the same conditions as for treatment planning. Systematic (preparation) setup errors can be introduced by...

journal_title：Medical physics

authors： Wu Q,Lockman D,Wong J,Yan D

更新日期：2007-05-01 00:00:00

abstract：:Single-photon emission-computed tomography (SPECT) imaging of deep brain structures is compromised by loss of photons due to attenuation. We have previously shown that a centrally peaked collimator sensitivity function can compensate for this phenomenon, increasing sensitivity over most of the brain. For dual-head ins...

journal_title：Medical physics

authors： Park MA,Moore SC,Kijewski MF

更新日期：2005-07-01 00:00:00

abstract：:Stereotactic Body Radiation Therapy (SBRT) is an important form of cancer therapy with increasingly broad application across a spectrum of tumor types in primary and metastatic settings. In this presentation the radiation biology, clinical experience from various trials, and cautionary updates on normal tissue toleran...

journal_title：Medical physics

authors： Read P

更新日期：2012-06-01 00:00:00

abstract：:With the increasing complexity of dose patterns external beam radiotherapy, there is a great need for new types of dosimeters. We studied the first prototype of a new dosimeter array consisting of water-equivalent plastic scintillating fibers for dose measurement in external beam radiotherapy. We found that this array...

journal_title：Medical physics

authors： Archambault L,Beddar AS,Gingras L,Lacroix F,Roy R,Beaulieu L

更新日期：2007-05-01 00:00:00

abstract：:Over the past decade, computed tomography (CT) theory, techniques and applications have undergone a rapid development. Since CT is so practical and useful, undoubtedly CT technology will continue advancing biomedical and non-biomedical applications. In this outlook article, we share our opinions on the research and de...

journal_title：Medical physics

authors： Wang G,Yu H,De Man B

更新日期：2008-03-01 00:00:00

abstract：PURPOSE:There is significant current interest in the use of biological image guidance in radiotherapy planning. In lung-cancer treatment, tumor motion due to respiration is known to be a limitation. This is particularly true in PET, where image data are collected over a number of minutes. An in-house-developed 4D PET a...

journal_title：Medical physics

authors： Perrin R,Evans PM,Webb S,Partridge M

更新日期：2010-02-01 00:00:00

abstract：:This paper describes a multileaf collimator, designed to obtain irregularly shaped neutron fields, that fits into an existing fixed field-size collimator system. The shape of the desired portal field is obtained by appropriately setting the position of each leaf of the collimator. The collimator consists of 40 polyeth...

journal_title：Medical physics

authors： Chu JC,Bloch P

更新日期：1987-03-01 00:00:00

abstract：:Dose calculations for treatment planning of photon beam radiotherapy require a model of the beam to drive the dose calculation models. The beam shaping process involves scattering and filtering that yield radiation components which vary with collimator settings. The necessity to model these components has motivated th...

journal_title：Medical physics

authors： Ahnesjö A,Weber L,Murman A,Saxner M,Thorslund I,Traneus E

更新日期：2005-06-01 00:00:00

abstract：:Due to practical limitations such as inter- and intraleaf transmission, nondivergent leaf end design, and leaf scatter, multileaf collimators (MLCs) are unable to accurately produce the ideal fluence patterns generated by inverse planning systems. Consequently, low dose regions receive substantially more radiation tha...

journal_title：Medical physics

authors： Popple RA,Fiveash JB,Brezovich IA

更新日期：2007-10-01 00:00:00

abstract：PURPOSE:The previously described 2D standardized vessel-wall-plus-plaque thickness (VWT) maps constructed from 3D ultrasound vessel wall measurements using an arc-length (AL) scaling approach adjusted the geometric variability of carotid arteries and has allowed for the comparisons of VWT distributions in longitudinal ...

journal_title：Medical physics

authors： Chen Y,Chiu B

更新日期：2016-12-01 00:00:00