Abstract:
PURPOSE:The purpose of the present study was to perform an analysis of the changes in the dynamic seroma cavity based on fiducial markers in early stage breast cancer patients treated with accelerated partial breast irradiation (APBI) using three-dimensional conformal external beam radiotherapy (3D-CRT). METHODS:A prospective, single arm trial was designed to investigate the utility of gold fiducial markers in image guided APBI using 3D-CRT. At the time of lumpectomy, four to six suture-type gold fiducial markers were sutured to the walls of the cavity. Patients were treated with a fractionation scheme consisting of 15 fractions with a fractional dose of 333 cGy. Treatment design and planning followed NSABP∕RTOG B-39 guidelines. During radiation treatment, daily kV imaging was performed and the markers were localized and tracked. The change in distance between fiducial markers was analyzed based on the planning CT and daily kV images. RESULTS:Thirty-four patients were simulated at an average of 28 days after surgery, and started the treatment on an average of 39 days after surgery. The average intermarker distance (AiMD) between fiducial markers was strongly correlated to seroma volume. The average reduction in AiMD was 19.1% (range 0.0%-41.4%) and 10.8% (range 0.0%-35.6%) for all the patients between simulation and completion of radiotherapy, and between simulation and beginning of radiotherapy, respectively. The change of AiMD fits an exponential function with a half-life of seroma shrinkage. The average half-life for seroma shrinkage was 15 days. After accounting for the reduction which started to occur after surgery through CT simulation and treatment, radiation was found to have minimal impact on the distance change over the treatment course. CONCLUSIONS:Using the marker distance change as a surrogate for seroma volume, it appears that the seroma cavity experiences an exponential reduction in size. The change in seroma size has implications in the size of the CTV, PTV, and percent of normal breast tissue irradiated when using 3D-CRT.
journal_name
Med Physjournal_title
Medical physicsauthors
Yue NJ,Haffty BG,Kearney T,Kirstein L,Chen S,Goyal Sdoi
10.1118/1.4788644subject
Has Abstractpub_date
2013-02-01 00:00:00pages
021717issue
2eissn
0094-2405issn
2473-4209journal_volume
40pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract:PURPOSE:In cardiac ablation therapy, accurate anatomic guidance is necessary to create effective tissue lesions for elimination of left atrial fibrillation. While fluoroscopy, ultrasound, and electroanatomic maps are important guidance tools, they lack information regarding detailed patient anatomy which can be obtaine...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4861712
更新日期:2014-02-01 00:00:00
abstract:PURPOSE:To introduce a pair of accelerated non-Cartesian acquisition principles that when combined, exploit the periodicity of k-space acquisition, and thereby enable acquisition of high-temporal cine Cardiac Magnetic Resonance (CMR). METHODS:The mathematical formulation of a noniterative, undersampled non-Cartesian c...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12234
更新日期:2017-07-01 00:00:00
abstract:PURPOSE:A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4772075
更新日期:2013-01-01 00:00:00
abstract:PURPOSE:One technical barrier to patient-specific computed tomography (CT) dosimetry has been the lack of computational tools for the automatic patient-specific multi-organ segmentation of CT images and rapid organ dose quantification. When previous CT images are available for the same body region of the patient, the a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14131
更新日期:2020-06-01 00:00:00
abstract::A modified neutron production target assembly has been developed to provide improved performance of the proton-cyclotron-based neutron radiotherapy facility at the University of Washington for applications involving neutron capture enhanced fast-neutron therapy. The new target produces a neutron beam that yields essen...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.598839
更新日期:2000-02-01 00:00:00
abstract:PURPOSE:The aim of this study was to evaluate the suitability of several detectors for the determination of absorbed dose in bone. METHODS:Three types of ultrathin LiF-based thermoluminescent dosimeters (TLDs)-two LiF:Mg,Cu,P-based (MCP-Ns and TLD-2000F) and a (7)Li-enriched LiF:Mg,Ti-based (MTS-7s)-as well as EBT2 Ga...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4886760
更新日期:2014-08-01 00:00:00
abstract:PURPOSE:For accurate tissue inhomogeneity correction in radiotherapy treatment planning, the authors had previously proposed a novel conversion of the energy-subtracted CT number to an electron density (ΔHU-ρe conversion), which provides a single linear relationship between ΔHU and ρe over a wide ρe range. The purpose ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4881327
更新日期:2014-07-01 00:00:00
abstract:PURPOSE:The primary feasibility steps of demonstrating the ability of microwave-induced thermoacoustic (TA) in phantoms have been previously reported. However, none were shown to target a diseased site in living subjects in thermoacoustic tomography (TAT) field so far. To determine the expressions of oncogenic surface ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3466696
更新日期:2010-08-01 00:00:00
abstract::A system for measuring two-dimensional (2D) dose distributions in orthogonal anatomical planes in the cranium was developed and used to evaluate the accuracy of coplanar conformal therapy using ExacTrac image guidance. Dose distributions were measured in the axial, sagittal, and coronal planes using a CIRS (Computeriz...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2955751
更新日期:2008-08-01 00:00:00
abstract:PURPOSE:Liver segmentation is an important prerequisite for the assessment of liver cancer treatment options like tumor resection, image-guided radiation therapy (IGRT), radiofrequency ablation, etc. The purpose of this work was to evaluate a new approach for liver segmentation. METHODS:A graph cuts segmentation metho...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3682171
更新日期:2012-03-01 00:00:00
abstract:PURPOSE:To evaluate dependence of measured dose on size and location of region of interest (ROI) in Gafchromic EBT3 film dosimetry. METHODS:Gafchromic EBT3 films were irradiated perpendicularly using the 6MV beam from a linear accelerator at 10 cm depth (100 cm SSD) of a 30 × 30 × 20 cm3 solid water phantom for a rang...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12885
更新日期:2018-05-01 00:00:00
abstract::Encapsulated, cylindrical sources containing 2, 5, and 8 Ci of 241Am have been designed and fabricated for intracavitary irradiation of uterine cancers. Exposure rates in air and dose rates in water around these sources have been measured using an ionization chamber and a lithium fluoride thermoluminescent dosimetry s...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596007
更新日期:1987-09-01 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
pub_type: 杂志文章
doi:10.1118/1.4734942
更新日期:2012-06-01 00:00:00
abstract::Intensity Modulated Arc Therapy (IMAT) is a rotational variant of Intensity Modulated Radiation Therapy (IMRT) that can be implemented with or without angular dose rate optimization. The purpose of this study is to determine the inter-relationship among arc range, Multi-Leaf Collimator (MLC) leaf positions and angular...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2965975
更新日期:2008-07-01 00:00:00
abstract::An applicator system for intraoperative radiation therapy has been fabricated which does not require physical docking with the accelerator. A dosimetric study has been completed which documents the properties of this system for a variety of electron beam energies, applicator sizes, collimator settings, both primary an...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596338
更新日期:1989-09-01 00:00:00
abstract:PURPOSE:Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum. METHODS:In the variational image segmen...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4945046
更新日期:2016-05-01 00:00:00
abstract::We are developing an automated stereo spot mammography technique for improved imaging of suspicious dense regions within digital mammograms. The technique entails the acquisition of a full-field digital mammogram, automated detection of a suspicious dense region within that mammogram by a computer aided detection (CAD...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1737492
更新日期:2004-06-01 00:00:00
abstract:PURPOSE:To quantitatively characterize the interfractional anatomic variations in post-operative radiation therapy (RT) for prostate bed, so that appropriate strategy that can fully address these variations can be developed. METHODS:A total of 102 daily pre-treatment CT acquired using an in-room CT (CTVision, Siemens)...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4734844
更新日期:2012-06-01 00:00:00
abstract::Significant advances have been made in recent years to improve photon dose calculation. However, accurate prediction of dose perturbation effects near the interfaces of different media, where charged particle equilibrium is not established, remain unsolved. Furthermore, changes in atomic number, which affect the multi...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597611
更新日期:1995-07-01 00:00:00
abstract::Several updated Monte Carlo (MC) codes are available to perform calculations of voxel S values for radionuclide targeted therapy. The aim of this work is to analyze the differences in the calculations obtained by different MC codes and their impact on absorbed dose evaluations performed by voxel dosimetry. Voxel S val...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3103401
更新日期:2009-05-01 00:00:00
abstract::The method of images is employed to insert the effects of the presence of a single lateral boundary on contrast functions previously derived for an infinite slab using a random walk model of photon transport. The predictions of the model for zero and extrapolated boundary conditions are compared with Monte Carlo (MC) ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.598687
更新日期:1999-09-01 00:00:00
abstract:PURPOSE:For cone-beam computed tomography (CBCT) systems, we propose a sphere phantom based method to estimate the full three-dimensional (3D) modulation transfer function (MTF). METHODS:The FDK reconstruction of CBCT system in a local region was modeled by a triple convolution operator. Afterward, we calculated the d...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14147
更新日期:2020-07-01 00:00:00
abstract:PURPOSE:To develop a novel three-dimensional (3D) hybrid-encoding framework using compressed sensing (CS) and Toeplitz encoding with variable phase-scrambled radio-frequency (RF) excitation, which has the following advantages: low power deposition of RF pulses, reduction of the signal dynamic range, no additional hardw...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.13987
更新日期:2020-04-01 00:00:00
abstract::Spectra, yields, average energies, and kerma rates in tissue of neutrons from 21-MeV deuteron bombardment of deuterium gas targets have been calculated for target thicknesses of 1, 3.5, and 5 MeV. A high pressure gas cell was constructed and was filled with 33 atm of D2 gas (equivalent to an energy loss of 3.5 MeV for...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594561
更新日期:1979-05-01 00:00:00
abstract:PURPOSE:The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4908000
更新日期:2015-04-01 00:00:00
abstract::Anisotropy of dose distributions around 103Pd, 125I, and 192Ir sources for interstitial brachytherapy was examined. Dose rates around 125I models 6702 and 6711 and 192Ir sources were measured using lithium fluoride thermoluminescence dosimeters (LiF TLDs) in a water-equivalent, solid phantom. From these measured data ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597110
更新日期:1993-09-01 00:00:00
abstract:PURPOSE:Wide bore CT scanners use extended field-of-view (eFOV) reconstruction algorithms to attempt to recreate tissue truncated due to large patient habitus. Radiation therapy planning systems rely on accurate CT numbers in order to correctly plan and calculate radiation dose. This study looks at the impact of eFOV r...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.13299
更新日期:2019-02-01 00:00:00
abstract::In this paper, the consistency of kilovoltage (tube potentials between 40 and 300 kV) x-ray beam dosimetry using the "in-air" method and the in-phantom measurement has been studied. The procedures for the measurement of the central-axis depth-dose curve, which serve as a link between the dose at the reference depth to...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.598448
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:Experimental dosimetry of high-dose-rate (HDR) 192 Ir brachytherapy (BT) sources is complicated due to high dose and dose-rate gradients, and softening of photon energy spectrum with depth. A single crystal synthetic diamond detector microDiamond (PTW 60019, Freiburg, Germany) has a small active volume, high se...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12694
更新日期:2018-01-01 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
pub_type: 杂志文章
doi:10.1118/1.596464
更新日期:1990-11-01 00:00:00