Abstract:
PURPOSE:In prostate radiotherapy, dose distribution may be calculated on CT images, while the MRI can be used to enhance soft tissue visualization. Therefore, a registration between MR and CT images could improve the overall treatment planning process, by improving visualization with a demonstrated interobserver delineation variability when segmenting the prostate, which in turn can lead to a more precise planning. This registration must compensate for prostate deformations caused by changes in size and form between the acquisitions of both modalities. METHODS:We present a fully automatic MRI/CT nonrigid registration method for prostate radiotherapy treatment planning. The proposed registration methodology is a two-step registration process involving both a rigid and a nonrigid registration step. The registration is constrained to volumes of interest in order to improve robustness and computational efficiency. The method is based on the maximization of the mutual information in combination with a deformation field parameterized by cubic B-Splines. RESULTS:The proposed method was validated on eight clinical patient datasets. Quantitative evaluation, using Hausdorff distance between prostate volumes in both images, indicated that the overall registration errors is 1.6 ± 0.2 mm, with a maximum error of less than 2.3 mm, for all patient datasets considered in this study. CONCLUSIONS:The proposed approach provides a promising solution for an effective and accurate prostate radiotherapy treatment planning since it satisfies the desired clinical accuracy.
journal_name
Med Physjournal_title
Medical physicsauthors
Hamdan I,Bert J,Rest CCL,Tasu JP,Boussion N,Valeri A,Dardenne G,Visvikis Ddoi
10.1002/mp.12629subject
Has Abstractpub_date
2017-12-01 00:00:00pages
6447-6455issue
12eissn
0094-2405issn
2473-4209journal_volume
44pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract:PURPOSE:Many biological objects, including neuronal dendrites, blood vasculature, airways, phylogenetic trees, produce tree structured data. Current methods of analysis either ignore the complex structure of trees or use distance-based methods which limit the scope of multivariate modeling. METHODS:We propose a branch...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12751
更新日期:2018-03-01 00:00:00
abstract:PURPOSE:The appearance of parenchymal∕stromal patterns in mammography have been characterized as having a Wiener power spectrum with an inverse power-law shape described by the exponential parameter, β. The amount of fibroglandular tissue, which can be quantified in terms of volumetric breast density (VBD), influences ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4736422
更新日期:2012-08-01 00:00:00
abstract::Studies suggest that clinical outcomes are improved in repeat trigeminal neuralgia (TN) Gamma Knife radiosurgery if a different part of the nerve from the previous radiosurgery is treated. The MR images taken in the first and repeat radiosurgery need to be coregistered to map the first radiosurgery volume onto the sec...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1944287
更新日期:2005-07-01 00:00:00
abstract:PURPOSE:We studied the sensitivity of a novel transmission fiber scintillator array designed and built for in line treatment verification. The purpose of this project is to assess the capability of the fiber detector array technology to detect treatment errors in real time without false positives to enhance patient saf...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4735217
更新日期:2012-06-01 00:00:00
abstract::Electron spectral reconstruction of medical accelerators from measured depth doses is a practical method for providing the input initial phase space distribution at the patient surface that is required by Monte Carlo treatment planning systems. The posed inverse problem of spectral reconstruction is ill conditioned an...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2161404
更新日期:2006-02-01 00:00:00
abstract:PURPOSE:Stringent quality assurance is required in MRI breast screening to ensure that different scanners and imaging protocols reach similar diagnostic performance. The authors propose a methodology, based on power spectrum analysis (PSA), to evaluate spatial resolution in clinical images. To demonstrate this approach...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4966704
更新日期:2016-12-01 00:00:00
abstract::We investigated protection strategies of organs at risk (OARs) in intensity modulated radiation therapy (IMRT). These strategies apply to delivery of IMRT to moving body anatomies that show relative displacement of OAR in close proximity to a tumor target. We formulated an efficient genetic algorithm which makes it po...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3132305
更新日期:2009-07-01 00:00:00
abstract:PURPOSE:Most radiation therapy optimization problems can be formulated as an unconstrained problem and solved efficiently by quasi-Newton methods such as the Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm. However, several next generation planning techniques such as total variation regularization- b...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12165
更新日期:2017-04-01 00:00:00
abstract::The NSD equation, D = 1850 x T0.11 x N0.24, is a celebrated transmogrification of Cohen's two well-known collations of data on response to clinical irradiations (3 degrees erythema and 0.90 ablation of skin cancer) in which the relation of D and T is fixed by the data selected by Cohen and the additional constraint th...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595034
更新日期:1981-11-01 00:00:00
abstract:PURPOSE:The purpose of this study was to detect and analyze anomalies between a large number of computed tomography (CT) scanners, tracked over time, utilized to collect human pulmonary CT data for a national multicenter study: chronic obstructive pulmonary disease genetic epidemiology study (COPDGene). METHODS:A cust...
journal_title:Medical physics
pub_type: 杂志文章,多中心研究
doi:10.1118/1.4747342
更新日期:2012-09-01 00:00:00
abstract::Extensive information has been made available relative to the physical aspects necessary for calculation of radiation absorbed dose from radiopharmaceuticals. A similar data base for the biological factors involved in these calculations has not been documented as thoroughly. The authors present an extensive literature...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594679
更新日期:1980-05-01 00:00:00
abstract::Segmentation of the lungs within magnetic resonance (MR) scans is a necessary step in the computer-based analysis of thoracic MR images. This process is often confounded by image acquisition artifacts and disease-induced morphological deformation. We have developed an automated method for lung segmentation that is ins...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2214165
更新日期:2006-09-01 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
pub_type: 杂志文章
doi:10.1002/mp.14554
更新日期:2020-12-01 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
pub_type: 杂志文章
doi:10.1002/mp.13968
更新日期:2020-03-01 00:00:00
abstract:PURPOSE:Alpha-emitting radionuclides exhibit a potential advantage for cancer treatments because they release large amounts of ionizing energy over a few cell diameters (50-80 μm), causing localized, irreparable double-strand DNA breaks that lead to cell death. Radioimmunotherapy (RIT) approaches using monoclonal antib...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4921997
更新日期:2015-07-01 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
pub_type: 杂志文章
doi:10.1118/1.4812678
更新日期:2013-08-01 00:00:00
abstract:PURPOSE:The authors discuss measurement methods and instrumentation useful for the characterization of the gray tracking performance of medical color monitors for diagnostic applications. The authors define gray tracking as the variability in the chromaticity of the gray levels in a color monitor. METHODS:The authors ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4953186
更新日期:2016-07-01 00:00:00
abstract::One limitation to the widespread implementation of Monte Carlo (MC) patient dose-calculation algorithms for radiotherapy is the lack of a general and accurate source model of the accelerator radiation source. Our aim in this work is to investigate the sensitivity of the photon-beam subsource distributions in a MC sour...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1884385
更新日期:2005-04-01 00:00:00
abstract::Approximately 70-85% of breast biopsies are performed on benign lesions. To reduce this high number of biopsies performed on benign lesions, a case-based reasoning (CBR) classifier was developed to predict biopsy results from BI-RADS findings. We used 1433 (931 benign) biopsy-proven mammographic cases. CBR similarity ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1501140
更新日期:2002-09-01 00:00:00
abstract::Recent absorbed-dose-based protocols allow for two methods of calibrating electron beams using plane-parallel chambers, one using the N(Co)D,w for a plane-parallel chamber, and the other relying on cross-calibration of the plane-parallel chamber in a high-energy electron beam against a cylindrical chamber which has an...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1449876
更新日期:2002-03-01 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
pub_type: 杂志文章
doi:10.1118/1.3669487
更新日期:2012-01-01 00:00:00
abstract::During the past decade the use of undersampled acquisition and constrained reconstruction have led to significant increases in data acquisition speed, SNR, spatial resolution and temporal resolution in MR imaging. When a separately acquired constraining image is combined with an angiographic time series the traditiona...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4735797
更新日期:2012-06-01 00:00:00
abstract::Conventional IMRT dose verification using film and ion chamber measurements is useful but limited with respect to the actual dose distribution received by the patient. The Monte Carlo simulation has been introduced as an independent dose verification tool for IMRT using the patient CT data and MLC leaf sequence files,...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2208916
更新日期:2006-07-01 00:00:00
abstract:PURPOSE:To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted i...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4905116
更新日期:2015-02-01 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
pub_type: 杂志文章
doi:10.1002/mp.12840
更新日期:2018-04-01 00:00:00
abstract:PURPOSE:Patient-specific QA of highly conformal radiotherapy treatments are usually conducted using 2D or 3D dosimetry of the incident dose distribution in a water-equivalent phantom. However, dosimeters typically used for this task usually lack in either spatial resolution or dose accuracy. The purpose of this work is...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4736526
更新日期:2012-08-01 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
pub_type: 杂志文章,多中心研究
doi:10.1118/1.4901299
更新日期:2015-01-01 00:00:00
abstract:PURPOSE:Dose verification in highly conformal radiation therapy such as IMRT or proton therapy can benefit from the high spatial resolution offered by radio-chromic films such as Gafchromic EBT or EBT2. Recently, a new generation of these films, EBT3, has become available. The composition and thickness of the sensitive...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4737890
更新日期:2012-08-01 00:00:00
abstract:PURPOSE:For stereotactic radiosurgery (SRS), accurate evaluation of dose-volume metrics for small structures is necessary. The purpose of this study was to compare the DVH metric capabilities of five commercially available SRS DVH analysis tools (Eclipse, Elements, Raystation, MIM, and Velocity). METHODS:DICOM RTdose ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14645
更新日期:2020-12-09 00:00:00
abstract::We measured the physical imaging performance of a 41 x 41 cm2 amorphous silicon flat panel detector designed for angiographic and R&F imaging applications using methods from the emerging IEC standard for the measurement of detective quantum efficiency (DQE) in digital radiographic detectors. Measurements on 12 product...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1609151
更新日期:2003-10-01 00:00:00