A Novel method to generate on-board 4D MRI using prior 4D MRI and on-board kV projections from a conventional LINAC for target localization in liver SBRT.

abstract：:A very important issue in contemporary inverse treatment radiotherapy planning is the specification of proper dose-volume constraints limiting the treatment planning algorithm from delivering high doses to the normal tissue surrounding the tumor. Recently we have proposed a method called reverse mapping of normal tiss...

journal_title：Medical physics

authors： Markov K,Schinkel C,Stavreva N,Stavrev P,Weldon M,Fallone BG

更新日期：2006-09-01 00:00:00

abstract：:We propose a new method based on statistical analysis technique to determine the minimum setup distance of a well chamber used in the calibration of 192Ir high dose rate (HDR). The chamber should be placed at least this distance away from any wall or from the floor in order to mitigate the effect of scatter. Three dif...

journal_title：Medical physics

authors： Chang L,Ho SY,Chui CS,Lee JH,Du YC,Chen T

更新日期：2008-06-01 00:00:00

abstract：PURPOSE:To investigate the dosimetric robustness of dynamically collimated proton therapy (DCPT) treatment plans delivered using a dynamic collimation system (DCS) with respect to random uncertainties in beam spot and collimator position as well as systematic offsets in the DCS mounting alignment. This work also demons...

journal_title：Medical physics

authors： Smith BR,Hyer DE,Culberson WS

更新日期：2020-08-01 00:00:00

abstract：:Coherent-scatter computed tomography (CSCT) is a novel imaging method we are developing to produce cross-sectional images based on the low-angle (<10 degrees) scatter properties of tissue. At diagnostic energies, this scatter is primarily coherent with properties dependent upon the molecular structure of the scatterer...

journal_title：Medical physics

authors： Batchelar DL,Cunningham IA

更新日期：2002-08-01 00:00:00

abstract：:In this article, we report on the development of a simple and accurate method for quality assurance of electron beam output and energy. Aluminum disks of thicknesses d(max) or d50 of the particular electron energy are positioned sequentially over a parallel-plate ion chamber and the ratio of the two signals is compare...

journal_title：Medical physics

authors： Woo MK,Videla NG

更新日期：2004-05-01 00:00:00

abstract：:An integrating solid-state dosimeter has been developed to detect ultraviolet radiation using the process of "direct" ultraviolet stimulation. This process yields a thermoluminescent signal after an exposure to ultraviolet radiation, without prior exposure to ionizing radiation. Magnesium oxide crystals were found to ...

journal_title：Medical physics

authors： Dhar A,DeWerd LA,Stoebe TG

更新日期：1976-11-01 00:00:00

abstract：PURPOSE:To investigate the sensitivity of the plan-class specific correction factor to dose distributions in composite nonstandard field dosimetry. METHODS:A cylindrical water-filled PMMA phantom was constructed at the center of which reference absorbed dose could be measured. Ten different TomoTherapy(®)-based IMRT f...

journal_title：Medical physics

authors： Chung E,Soisson E,Seuntjens J

更新日期：2012-01-01 00:00:00

abstract：:A cumulative dose histogram is the graph of an integral function integrated over a domain VCR3 and is dubbed the dose-volume histogram (DVH), the dose-surface histogram (DSH) or the dose-wall histogram (DWH), depending on the dimension and structure of the region V. This paper presents a comparative study of the three...

journal_title：Medical physics

authors： Song JS,Albert M,D'Amico AV,Cormack RA

更新日期：2005-02-01 00:00:00

abstract：PURPOSE:To evaluate the treatment planning system (TPS) performance of the ZAP-X stereotactic radiosurgery (SRS) system through nondosimetric, dosimetric, and end-to-end (E2E) tests. METHODS:A comprehensive set of TPS commissioning and validation tests were developed using published guidelines. Nondosimetric validatio...

journal_title：Medical physics

authors： Srivastava SP,Jani SS,Pinnaduwage DS,Yan X,Rogers L,Barranco FD,Barani IJ,Sorensen S

更新日期：2021-01-28 00:00:00

abstract：:The aim of this work was to test the suitability of a PTW diamond detector for nonreference condition dosimetry in photon beams of different energy (6 and 25 MV) and field size (from 2.6 cm x 2.6 cm to 10 cm x 10 cm). Diamond behavior was compared to that of a Scanditronix p-type silicon diode and a Scanditronix RK io...

journal_title：Medical physics

authors： Bucciolini M,Buonamici FB,Mazzocchi S,De Angelis C,Onori S,Cirrone GA

更新日期：2003-08-01 00:00:00

abstract：PURPOSE:The purpose of this work was to investigate the use of an experimental complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) for tracking of moving fiducial markers during radiotherapy. METHODS:The APS has an active area of 5.4 × 5.4 cm and maximum full frame read-out rate of 20 frame s(-1),...

journal_title：Medical physics

authors： Osmond JP,Zin HM,Harris EJ,Lupica G,Allinson NM,Evans PM

更新日期：2011-11-01 00:00:00

abstract：:The data from Meisberger et al. [Radiology 90, 953-957 (1968)] are often used as a basis for dose calculations in brachytherapy. In order to describe the absorbed dose in water around a brachytherapy point source, Meisberger provided a polynomial fit for different isotopes taking into account the effect of attenuation...

journal_title：Medical physics

authors： Tiourina TB,Dries WJ,van der Linden PM

更新日期：1995-05-01 00:00:00

abstract：PURPOSE:Helical tomotherapy is a complex delivery technique, integrating CT image guidance and intensity modulated radiotherapy in a single system. The integration of the CT detector ring on the gantry not only allows patient position verification but is also often used to perform various QA procedures. This convenienc...

journal_title：Medical physics

authors： Wong JH,Hardcastle N,Tomé WA,Bayliss A,Tolakanahalli R,Lerch ML,Petasecca M,Carolan M,Metcalfe P,Rosenfeld AB

更新日期：2011-04-01 00:00:00

abstract：:The same calibration grade ionization chamber and electrometer were sequentially sent to all five currently AAPM Accredited Dosimetry Calibration Laboratories (ADCL). A Cesium-137 based check device was utilized to ensure chamber and electrometer factor constancy and showed a maximum deviation of 0.32% (typically less...

journal_title：Medical physics

authors： Blackwell CR,McCullough EC

更新日期：1992-01-01 00:00:00

abstract：:Recently, new imaging modalities based on the detection of weak phase perturbations effects, among which are phase contrast and diffraction imaging, have been developed by several researchers. Due to their high sensitivity to weakly absorbing details, these techniques seem to be very promising for applications in the ...

journal_title：Medical physics

authors： Olivo A,Arfelli F,Cantatore G,Longo R,Menk RH,Pani S,Prest M,Poropat P,Rigon L,Tromba G,Vallazza E,Castelli E

更新日期：2001-08-01 00:00:00

abstract：PURPOSE:To investigate how the setting of optimization parameters, fractional dose and tuning structure in tomotherapy treatment planning affects plan dosimetric quality and treatment efficiency. METHODS:A digital phantom to simulate head and neck radiotherapy was constructed for this study. Tumor was 10cm long C-shap...

journal_title：Medical physics

authors： Lian J,Burkhardt K,Chera B,Chang S

更新日期：2012-06-01 00:00:00

abstract：:The purpose of this study was to implement the Monte Carlo method for clinical radiotherapy dose calculations. We used the EGS4/BEAM code to obtain the phase-space data for 6-20 MeV electron beams and 4, 6, and 15 MV photon beams for Varian Clinac 1800, 2100C, and 2300CD accelerators. A multiple-source model was used ...

journal_title：Medical physics

authors： Ma CM,Mok E,Kapur A,Pawlicki T,Findley D,Brain S,Forster K,Boyer AL

更新日期：1999-10-01 00:00:00

abstract：:A scintillation dosemeter is calibrated for 90Sr/90Y beta rays from an ophthalmic applicator, using an extrapolation ionization chamber as a reference instrument. The calibration factor for the scintillation dosemeter agrees with that given by the manufacturer of the dosemeter within ca. 2%. The estimated overall unce...

journal_title：Medical physics

authors： Hakanen AT,Sipilä PM,Kosunen A

更新日期：2004-05-01 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：:Accurate segmentation of microcalcifications in mammography is crucial for the quantification of morphologic properties by features incorporated in computer-aided diagnosis schemes. A novel segmentation method is proposed implementing active rays (polar-transformed active contours) on B-spline wavelet representation t...

journal_title：Medical physics

authors： Arikidis NS,Skiadopoulos S,Karahaliou A,Likaki E,Panayiotakis G,Costaridou L

更新日期：2008-11-01 00:00:00

abstract：PURPOSE:To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. METHODS:An iterative image reconstruction that sought to minimize a weighted leas...

journal_title：Medical physics

authors： Xu Q,Yang D,Tan J,Anastasio M

更新日期：2012-06-01 00:00:00

abstract：:Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved ...

journal_title：Medical physics

authors： Parodi K

更新日期：2015-12-01 00:00:00

abstract：PURPOSE:External beam radiation therapy (EBRT) usually uses heterogeneous dose distributions in a given volume. Designing detectors for quality control of these treatments is still a developing subject. The size of the detectors should be small to enhance spatial resolution and ensure low perturbation of the beam. A hi...

journal_title：Medical physics

authors： Barbés B,Azcona JD,Burguete J,Martí-Climent JM

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:With increased use of handheld and tablet display devices for viewing medical images, methods for consistently measuring reflectivity of the devices are needed. In this note, the authors report on the characterization of diffuse reflections for handheld display devices including mobile phones and tablets using ...

journal_title：Medical physics

authors： Liu P,Badano A

更新日期：2014-08-01 00:00:00

abstract：PURPOSE:Brachytherapy is a treatment modality which delivers large doses of radiation in a reduced number of visits. Since a small number of large dose-per-fraction is administered in high dose rate brachytherapy, ensuring the right dose is delivered is highly critical. In this work, a scintillation detector is coupled...

journal_title：Medical physics

authors： Tho D,Beaulieu L

更新日期：2019-05-01 00:00:00

abstract：:Nowadays, digital subtraction angiography systems must be able to sustain real-time acquisition (30 frames per second) of 512 x 512 x 8 bit images and store several sequences of such images on low cost and general-purpose mass memories. Concretely, that means a 7.8 Mbytes per second rate and about 780 Mbytes disk spac...

journal_title：Medical physics

authors： Liénard J

更新日期：1989-11-01 00:00:00

abstract：PURPOSE:Primary goal of this study is to select optimal registration schemes in the framework of interstitial lung disease (ILD) follow-up analysis in CT. METHODS:A set of 128 multiresolution schemes composed of multiresolution nonrigid and combinations of rigid and nonrigid registration schemes are evaluated, utilizi...

journal_title：Medical physics

authors： Vlachopoulos G,Korfiatis P,Skiadopoulos S,Kazantzi A,Kalogeropoulou C,Pratikakis I,Costaridou L

更新日期：2015-08-01 00:00:00

abstract：PURPOSE:Previous studies have shown atlas-based segmentation using a single best matched (SBM) atlas subject can significantly reduce contouring time. A new multi-atlas approach has been shown to provide greater accuracy than SBM for cancer of the head and neck. The goal of this study was to evaluate the multi-atlas te...

journal_title：Medical physics

authors： Pirozzi S,Horvat M,Piper J,Nelson A

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:The authors' objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-sp...

journal_title：Medical physics

authors： Grimes J,Celler A

更新日期：2014-09-01 00:00:00

abstract：PURPOSE:Currently applied calibration approaches lead to satisfying 3D roadmapping overlay and 3D reconstruction accuracies; however, the required calibration times are extensive. The aim of this paper is the introduction of a novel model-based approach for geometric system calibrations, leading to a significant reduct...

journal_title：Medical physics

authors： van der Maas R,de Jager B,Steinbuch M,Dries J

更新日期：2015-11-01 00:00:00