Abstract:
PURPOSE:The authors use reduced-order constrained optimization (ROCO) to create clinically acceptable IMRT plans quickly and automatically for advanced lung cancer patients. Their new ROCO implementation works with the treatment planning system and full dose calculation used at Memorial Sloan-Kettering Cancer Center (MSKCC). The authors have implemented mean dose hard constraints, along with the point-dose and dose-volume constraints that the authors used for our previous work on the prostate. METHODS:ROCO consists of three major steps. First, the space of treatment plans is sampled by solving a series of optimization problems using penalty-based quadratic objective functions. Next, an efficient basis for this space is found via principal component analysis (PCA); this reduces the dimensionality of the problem. Finally, a constrained optimization problem is solved over this basis to find a clinically acceptable IMRT plan. Dimensionality reduction makes constrained optimization computationally efficient. RESULTS:The authors apply ROCO to 12 stage III non-small-cell lung cancer (NSCLC) cases, generating IMRT plans that meet all clinical constraints and are clinically acceptable, and demonstrate that they are competitive with the clinical treatment plans. The authors also test how many samples and PCA modes are necessary to achieve an adequate lung plan, demonstrate the importance of long-range dose calculation for ROCO, and evaluate the performance of nonspecific normal tissue ("rind") constraints in ROCO treatment planning for the lung. Finally, authors show that ROCO can save time for planners, and they estimate that in the clinic, planning using their approach would save a median of 105 min for the patients in the study. CONCLUSIONS:New challenges arise when applying ROCO to the lung site, which include the lack of a class solution, a larger treatment site, an increased number of parameters and beamlets, a variable number of beams and beam arrangement, and the customary use of rinds in clinical plans to avoid high-dose areas outside the PTV. In the authors previous work, use of an approximate dose calculation in the hard constraint optimization sometimes meant that clinical constraints were not met when evaluated with the full dose calculation. This difficulty has been removed in the current work by using the full dose calculation in the hard constraint optimization. The authors have demonstrated that ROCO offers a fast and automatic way to create IMRT plans for advanced NSCLC, which extends their previous application of ROCO to prostate cancer IMRT planning.
journal_name
Med Physjournal_title
Medical physicsauthors
Stabenau H,Rivera L,Yorke E,Yang J,Lu R,Radke RJ,Jackson Adoi
10.1118/1.3575416subject
Has Abstractpub_date
2011-05-01 00:00:00pages
2731-41issue
5eissn
0094-2405issn
2473-4209journal_volume
38pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract::Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Sev...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1624755
更新日期:2003-12-01 00:00:00
abstract::Assessment of clinic and site specific margins are essential for the effective use of three-dimensional and intensity modulated radiation therapy. An electronic portal imaging device (EPID) based methodology is introduced which allows individual and population based CTV-to-PTV margins to be determined and compared wit...
journal_title:Medical physics
pub_type: 临床试验,杂志文章
doi:10.1118/1.1800712
更新日期:2004-11-01 00:00:00
abstract::In this paper, the authors review the field of resolution modeling in positron emission tomography (PET) image reconstruction, also referred to as point-spread-function modeling. The review includes theoretical analysis of the resolution modeling framework as well as an overview of various approaches in the literature...
journal_title:Medical physics
pub_type: 杂志文章,评审
doi:10.1118/1.4800806
更新日期:2013-06-01 00:00:00
abstract:PURPOSE:High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly (192)Ir with an air KERMA strength range between 20,000 and 40,000 U, where 1 U = 1 μGy m(2)/h in a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4822736
更新日期:2013-11-01 00:00:00
abstract:PURPOSE:The application of compressed sensing (CS) technology in magnetic resonance imaging (MRI) is to accelerate the MRI scan speed by incoherent undersampling of k-space data and nonlinear iterative reconstruction of MRI images. This paper generalizes the existing rosette trajectories to configure the sampling patte...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4928152
更新日期:2015-09-01 00:00:00
abstract::Due to practical limitations in data acquisition, 3-D computed tomography systems must attempt to provide rapid reconstructions of acceptable quality from a limited number of views. The use of convolution backprojection (CBP) for image reconstruction from an inadequate number of projections, results in view aliasing a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.598606
更新日期:1999-06-01 00:00:00
abstract::Angioplasty balloons inflated with a solution of the beta-emitter Re-188 have been used for intravascular brachytherapy to prevent restenosis. Coronary stents are in extensive clinical use for the treatment of de novo atherosclerotic stenoses. In this study, the effect of an interposed stent on the dose distribution h...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1533749
更新日期:2003-02-01 00:00:00
abstract:PURPOSE:Anomalous pixels may be defined as those pixels whose exposure response relationship is deviant from the typical, expected or calibrated response. A group of anomalous pixels may Result in visible correlated artifacts. Here we demonstrate an approach to identify anomalous pixels and correlated artifacts using f...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4734820
更新日期:2012-06-01 00:00:00
abstract::Multimodality NIR spectroscopy systems offer the possibility of region-based vascular and molecular characterization of tissue in vivo. However, computationally efficient 3D image reconstruction algorithms specific to these image-guided systems currently do not exist. Image reconstruction is often based on finite-elem...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2795832
更新日期:2007-11-01 00:00:00
abstract::An in vitro radiographic technique which uses saline/iodine displacement has been developed to study the thickness of bone-equivalent and soft-tissue-equivalent materials within atherosclerotic plaques in arterial specimens which have been cut open longitudinally and laid flat. Results concerning the optimization of t...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597916
更新日期:1997-01-01 00:00:00
abstract::In this article, we present a characterization of the effect of difference of Gaussians (DoG) filters in the detection of mammographic regions. DoG filters have been used previously in mammographic mass computer-aided detection (CAD) systems. As DoG filters are constructed from the subtraction of two bivariate Gaussia...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2358326
更新日期:2006-11-01 00:00:00
abstract::We discuss a formalism for clinical proton beam dosimetry based on the use of ionization chamber absorbed dose-to-water calibration and beam quality correction factors. A quantity kQ, the beam quality correction factor, is defined which corrects the absorbed dose-to-water calibration factor ND,w in a reference beam of...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597768
更新日期:1996-01-01 00:00:00
abstract::This paper outlines a method for determining proper removal-diffusion parameters to be used in removal-diffusion theory calculations for the purpose of BNCT treatment planning. Additionally, this paper demonstrates that, given the proper choice of removal-diffusion parameters, removal-diffusion theory may provide an a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1386424
更新日期:2001-09-01 00:00:00
abstract::Although x-ray computed tomography (CT) has been in clinical use for over 3 decades, spectral optimization has not been a topic of great concern; high voltages around 120 kV have been in use since the beginning of CT. It is the purpose of this study to analyze, in a rigorous manner, the energies at which the patient d...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3075901
更新日期:2009-03-01 00:00:00
abstract:PURPOSE:Small animal immobilization devices facilitate positioning of animals for reproducible imaging and accurate focal radiation therapy. In this study, the authors demonstrate the use of three-dimensional (3D) printing technology to fabricate a custom-designed mouse head restraint. The authors evaluate the accuracy...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4933200
更新日期:2015-11-01 00:00:00
abstract:PURPOSE:Colitis refers to inflammation of the inner lining of the colon that is frequently associated with infection and allergic reactions. In this paper, we propose deep convolutional neural networks methods for lesion-level colitis detection and a support vector machine (SVM) classifier for patient-level colitis dia...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12399
更新日期:2017-09-01 00:00:00
abstract::The ability to control thermal drifts is essential in operating a calorimeter. We investigated a thermal enclosure, which envelops the calorimeter with temperature-regulated air, thus thermally isolating the calorimeter from the room. The desired temperature in the enclosure is controlled by a control circuit and a th...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595760
更新日期:1985-05-01 00:00:00
abstract::A new approach to the calculation of the x-ray spectrum emerging from an x-ray tube is proposed. Theoretical results for the bremsstrahlung cross section appearing in the literature are summarized. Four different treatments of electron penetration, based on the work presented in Part I, are then used to generate brems...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2734726
更新日期:2007-06-01 00:00:00
abstract:PURPOSE:The purpose of this work is twofold: First, to characterize the artifacts occurring in helical 4D-CT imaging; second, to propose a method that can automatically identify the artifacts in 4D-CT images. The authors have designed a process that can automatically identify the artifacts in 4D-CT images, which may be...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3553556
更新日期:2011-04-01 00:00:00
abstract::The 1983 AAPM protocol for the determination of absorbed dose from high-energy photon and electron beams recommends using Pion (the reciprocal of collection efficiency), as determined by the two-voltage technique, to correct for recombination losses in ionization chambers. Methods and data for the determination of ion...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595574
更新日期:1984-11-01 00:00:00
abstract::An important aspect of heavy charged particle radiotherapy is its ability to localize dose to the target volume. Current techniques generally employ beam delivery schemes which use range modulated beams in which the Bragg peak is spread out over a range of depths. The range modulation is constant over the entire beam ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595419
更新日期:1983-11-01 00:00:00
abstract:PURPOSE:To introduce video surface imaging guidance in synchronization with 4D cone-beam CT (CBCT) scans, and in combination with respiration- gated or target-tracked dose delivery to treat mobile tumors, without collaterally damaging nearby critical structures. METHODS:The approach uses the concept that the integral ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4734688
更新日期:2012-06-01 00:00:00
abstract::In this study, BrachyDose, a recently developed EGSnrc Monte Carlo code for rapid brachytherapy dose calculations, has been benchmarked by reproducing previously published dosimetry parameters for three brachytherapy seeds with varied internal structure and encapsulation. Calculations are performed for two 125I seeds ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2400843
更新日期:2007-02-01 00:00:00
abstract::During our routine calibration of a Varian Clinac-20 linear accelerator, the absorbed dose for a fixed monitor unit (mu) was found to decrease with increasing dose rate. Between dose rates of 100 and 500 mu/min, there was up to 20% difference in absorbed dose for a 20-MeV electron beam. The cause of this problem was a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596192
更新日期:1988-09-01 00:00:00
abstract:PURPOSE:The aim of this work is to investigate the predictive power of a common conventional intensity modulated radiation therapy (IMRT) quality assurance (QA) performance metric, the gamma passing rate (%GP), through the analysis of the sensitivity and of the correlation between %GP and different dose discrepancies b...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4767763
更新日期:2012-12-01 00:00:00
abstract::We propose a new starting point for comparing planar dose distributions using a Jacobian-based measure. The measure is normalization independent, i.e., is sensitive to dose patterns while not being biased by global dose scaling. The measure is free of tunable parameters and is bounded between zero and one. We also pro...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2982136
更新日期:2008-11-01 00:00:00
abstract::The purpose of this paper is to determine the correlation between dose-volume histogram (DVH) and dose wall-histogram (DWH) in the evaluation of rectal complications for prostate cancer patients treated with three-dimensional conformal radiotherapy (3D-CRT). A retrospective analysis of DVHs and DWHs of a subset of 25 ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1951427
更新日期:2005-08-01 00:00:00
abstract::The large variation of x-ray fluence at the detector in cone-beam CT (CBCT) poses a significant challenge to detectors' limited dynamic range, resulting in the loss of skinline as well as reduction of CT number accuracy, contrast-to-noise ratio, and image uniformity. The authors investigate the performance of a bowtie...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3017470
更新日期:2009-01-01 00:00:00
abstract::We investigated the utility of three manual planimetric methods to quantify carotid plaque volume. A single observer measured 15 individual plaques from 15 three-dimensional (3D) ultrasound (3D US) images of patients ten times each using three different planimetric approaches. Individual plaque volumes were measured (...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2715487
更新日期:2007-04-01 00:00:00
abstract::The number of intensity modulated radiation therapy (IMRT) procedures is continuously growing worldwide and it is necessary to develop tools for patient specific quality assurance (QA) that avoid using machine time that could be employed in treating additional patients. One way of achieving this goal is to perform a m...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2815359
更新日期:2008-01-01 00:00:00