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 safety. METHODS:We developed a linear scintillator array detector using radiation hard scintillating fibers and high speed parallel signal conditioning and data acquisition to monitor external beam treatment fluence in real time. The detector captures and resolves the time and amplitude of each linac pulse at each MLC segment. The detector has 60 fibers aligned to each MLC leaf and two output channels per fiber. The data is captured by a high speed parallel digitizer to determine the IMRT beam output delivered to a patient in real time. We evaluated the detector peak pulse linearity according to dose rate, MLC positioning, and beam energy. We analyzed the detector sensitivity, signal to noise ratio, and pulse distribution statistics to determine beam output and fluence in real time. RESULTS:We analyzed the response of the detector to 6 MV and 10 MV photon beams. The statistical analysis of the detected linac pulses indicates that a minimum of 20 pulses are required to evaluate MLC positioning and fluence with 3 mm and 3% resolution, respectively. During testing, no false positives were detected. Linearity with respect to output rate, MLC or jaw opening, and fluence is within 2%. CONCLUSIONS:Measured sensitivity and signal to noise ratio of a real time linear fiber array detector show that delivered beam fluence can be monitored every 55 msec, with no observed false positives during treatment to provide in vivo real time patient safety and beam monitoring.
journal_name
Med Physjournal_title
Medical physicsauthors
Izaguirre EW,Price SG,Smajlovic S,Yaddanapudi S,Wooten H,Mutic Sdoi
10.1118/1.4735217subject
Has Abstractpub_date
2012-06-01 00:00:00pages
3739issue
6Part12eissn
0094-2405issn
2473-4209journal_volume
39pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract:PURPOSE:The combination of nonhuman primates (NHPs) with the state-of-the-art molecular imaging technologies allows for within-subject longitudinal research aiming at gaining new insights into human normal and disease conditions and provides an ideal foundation for future translational studies of new diagnostic tools, ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14333
更新日期:2020-09-01 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
pub_type: 杂志文章
doi:10.1118/1.2991286
更新日期:2008-11-01 00:00:00
abstract:PURPOSE:The purpose of this study was to assess the accuracy of a Monte Carlo simulation-based method for estimating radiation dose from multidetector computed tomography (MDCT) by comparing simulated doses in ten patients to in-vivo dose measurements. METHODS:MD Anderson Cancer Center Institutional Review Board appro...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4906178
更新日期:2015-02-01 00:00:00
abstract:PURPOSE:The lateral edge of a proton therapy beam is commonly used to achieve conformality to the treatment volume where critical structures reside close to the target. However, when treating shallow depths, the lateral edge of a pencil beam scanning (PBS) system may be broader than that of a double scattered (DS) syst...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4941957
更新日期:2016-03-01 00:00:00
abstract:PURPOSE:In this abstract, we discuss a biomechanical head and neck model that will be able to represent patient setup variations as well as physiologic changes and subsequently enable dose calculations on the deformed anatomy. METHODS:We selected Multi Pose MRI as the imaging modality to aid in model development and v...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4734893
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:In C-arm computed tomography (CT), the field of view (FOV) is often not sufficient to acquire certain anatomical structures, e.g., a full hip or thorax. Proposed methods to extend the FOV use a fixed detector displacement and a 360° scan range to double the radius of the FOV. These trajectories are designed for...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4915542
更新日期:2015-05-01 00:00:00
abstract::The objective of this study was to compare the contrast-detail performance of five different commercial liquid crystal displays (LCDs) to other LCD and cathode-ray tube (CRT) displays for medical applications. A contrast-detail phantom, supplemented with 5 in. of acrylic, was imaged on a commercial digital radiographi...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2868780
更新日期:2008-04-01 00:00:00
abstract::A conceptual design is presented showing that, by judiciously choosing the beryllium target thickness and the backstop material, improvements can be achieved in dose-rate, skin sparing, and penetration of neutron beams generated by the same proton accelerator. ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594748
更新日期:1980-09-01 00:00:00
abstract:PURPOSE:The aim of this work is to search for new metrics that could give more reliable acceptance/rejection criteria on the IMRT verification process and to offer solutions to the discrepancies found among different conventional metrics. Therefore, besides conventional metrics, new ones are proposed and evaluated with...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4964796
更新日期:2016-11-01 00:00:00
abstract::Linac calibration is done in water, but patients are comprised primarily of soft tissue. Conceptually, and specified in NRG/RTOG trials, dose should be reported as dose-to-muscle to describe the dose to the patient. Historically, the dose-to-water of the linac calibration was often converted to dose-to-muscle for pati...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.13995
更新日期:2020-03-01 00:00:00
abstract:PURPOSE:Motion compensated positron emission tomography (PET) imaging requires detecting and monitoring of patient body motion. We developed a semiautomatic list-mode method to track the three-dimensional (3D) motion of fiducial positron-emitting markers during PET imaging. METHODS:A previously developed motion tracki...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14206
更新日期:2020-08-01 00:00:00
abstract::The aim of the work was to investigate in advance the dosimetric properties of a new multileaf collimator (MLC) concept with the help of Monte Carlo (MC) simulations prior to the production of a prototype. The geometrical design of the MLC was implemented in the MC code GEANT4. For the simulation of a 6 MV treatment b...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2181298
更新日期:2006-04-01 00:00:00
abstract::In patients with lymphoma, identification and quantification of the tumor extent on serial CT examinations is critical for assessing tumor response to therapy. In this paper, we present a computer method to automatically match and segment lymphomas in follow-up CT images. The method requires that target lymph nodes in...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2404617
更新日期:2007-01-01 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::The BEAMnrc/EGSnrc Monte Carlo code system is employed to develop a model of the National Research Council of Canada primary standard of absorbed dose to tissue in a beta radiation field, comprising an extrapolation chamber and 90Sr/90Y beta source. We benchmark the model against the measured response of the chamber i...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1997347
更新日期:2005-10-01 00:00:00
abstract:PURPOSE:To develop a fluoroscopy imaging based approach that can determine the magnitude and phase variation in respiratory motion against the treatment planning images in order to quantify the online patient setup deviation in thoracic cancer IGRT for the real time adaptive patient positionadjustment. METHODS:A numer...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4734876
更新日期:2012-06-01 00:00:00
abstract::The wall of an ionization chamber is commonly assumed to have a negligible effect on chamber response in electron beams. For cylindrical chambers with thin walls this assumption is valid. However, parallel-plate chambers commonly possess large mechanical supports which may affect chamber response in a manner not accou...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596165
更新日期:1988-01-01 00:00:00
abstract::Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3147143
更新日期:2009-07-01 00:00:00
abstract:PURPOSE:Colon cancer is a major public health problem due to its high disease rate and death toll worldwide. The use of FTIR microscopy in the field of cancer diagnosis has become attractive over the past 20 years. In the present study, the authors investigated the potential of FTIR microscopy to define spectral change...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3298013
更新日期:2010-03-01 00:00:00
abstract:PURPOSE:To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. METHODS:The authors show that by taking an...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4859295
更新日期:2014-02-01 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::While simple, intravascular brachytherapy (IVB) presents a considerable potential for harm to the patient. The medical physicist maintains the responsibility to minimize the likelihood of operational problems or dosimetric errors. The principals for safe operation remain the same as with any radiotherapy treatment: to...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1524167
更新日期:2002-12-01 00:00:00
abstract::A commercially available open MRI unit is under routine use for radiation therapy simulation. The effects of a gradient distortion correction (GDC) program used to post process the images were assessed by comparison with the known geometry of a phantom. The GDC reduced the magnitude of the distortions at the periphery...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1513991
更新日期:2002-11-01 00:00:00
abstract::Using stable materials capable of mimicking any soft tissues of the human body--quantitatively with respect to speed of sound, density, and attenuation coefficient and semiquantitatively with respect to scatter--we have constructed a torso section phantom containing simulated bowel gas, kidney, kidney fat pad, liver, ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594657
更新日期:1980-01-01 00:00:00
abstract:PURPOSE:The automated correct segmentation of left and right lungs is a nontrivial problem, because the tissue layer between both lungs can be quite thin. In the case of lung segmentation with left and right lung models, overlapping segmentations can occur. In this paper, the authors address this issue and propose a so...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4894817
更新日期:2014-10-01 00:00:00
abstract::Functional single photon emission computed tomography (SPECT) images of brain activation are based on a comparison of base line and activation images. The correctness of the functional images depends, among other factors, on the accurate spatial registration (alignment) of the base line and activation image data. The ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597412
更新日期:1994-10-01 00:00:00
abstract::One of the methods currently being used to treat choroidal melanoma employs an episcleral plaque containing I-125 radioactive seeds. However, comprehensive dosimetry studies on the plaque are scarce and controversial. For this work, we use film to study the dosimetry outside the lip of the gold shield of the eye plaqu...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596556
更新日期:1990-09-01 00:00:00
abstract::Effects of changes in the physics of EGSnrc compared to EGS4/PRESTA on energy deposition kernels for monoenergetic photons and on dose point kernels for beta sources in water are investigated. In the diagnostic energy range, Compton binding corrections were found to increase the primary energy fraction up to 4.5% at 3...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1861412
更新日期:2005-03-01 00:00:00
abstract::Some limitations of conventional two-dimensional computer programs used to plan radiation therapy are presented. These include: a lack of involvement in defining the clinical problem; deficiencies in the algorithms for computing dose; failure to compute dose throughout the volume of interest; an inability to handle tr...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595226
更新日期:1982-07-01 00:00:00
abstract:PURPOSE:To build a statistical model to quantitatively correlate the anatomic features of structures and the corresponding dose-volume histogram (DVH) of head and neck (HN) Tomotherapy (Tomo) plans. To study if the model built upon one intensity modulated radiation therapy (IMRT) technique (such as conventional Linac) ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4828788
更新日期:2013-12-01 00:00:00