Abstract:
PURPOSE:A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. METHODS:A total of 300 patients receiving lung SBRT treatments in four different institutions were retrospectively reviewed. The treatments were delivered using Linac based SBRT (160 patients) or image guided robotic radiosurgery (140). Most tumors were located peripherally (250/300). Median fractional doses and ranges were 18 Gy (8-20 Gy), 12 Gy (6-15 Gy), and 10 Gy (5-12 Gy) for three, four, and five fraction treatments, respectively. The following planning criteria derived from RTOG trials and the literature were used to evaluate the treatment plans: planning target volumes, PTVV 100 ≥ 95% and PTVV 95 ≥ 99%; conformality indices, CI100% < 1.2 and CI50% range of 2.9-5.9 dependent on PTV; total lung-ITV: V20Gy < 10%, V12.5Gy < 15%, and V5Gy < 37%; contralateral lung V5Gy < 26%; and maximum doses for spinal cord, esophagus, trachea/bronchus, and heart and great vessels. Populations were grouped by number of fractions, and dosimetric criteria satisfaction rates (CSRs) were reported. RESULTS:Five fraction regimens were the most common lung SBRT fractionation (46%). The median PTV was 27.2 cm(3) (range: 3.8-419.5 cm(3)). For all plans: mean PTVV 100 was 94.5% (±5.6%, planning CSR: 69.8%), mean PTVV 95 was 98.1% (±4.1%, CSR: 69.5%), mean CI100% was 1.14 (±0.21, CSR: 79.1%, and 16.5% within minor deviation), and mean CI50% was 5.63 (±2.8, CSR: 33.0%, and 28.0% within minor deviation). When comparing plans based on location, peripherally located tumors displayed higher PTVV 100 and PTVV 95 CSR (71.5% and 71.9%, respectively) than centrally located tumors (61.2% and 57.1%, respectively). Overall, the planning criteria were met for all the critical structure such as lung, heart, spinal cord, esophagus, and trachea/bronchus for at least 85% of the patients. CONCLUSIONS:Among the various parameters that were used to evaluate the SBRT plans, the CI100% and CI50% were the most challenging criteria to meet. Although the CSRs of organs at risk were higher among all cases, their proximity to the PTV was a significant factor.
journal_name
Med Physjournal_title
Medical physicsauthors
Woerner A,Roeske JC,Harkenrider MM,Fan J,Aydogan B,Koshy M,Laureckas R,Vali F,Campana M,Surucu Mdoi
10.1118/1.4926551subject
Has Abstractpub_date
2015-08-01 00:00:00pages
4629-35issue
8eissn
0094-2405issn
2473-4209journal_volume
42pub_type
杂志文章,多中心研究相关文献
MEDICAL PHYSICS文献大全abstract::Accurate dosimetry of small-field photon beams tends to be difficult to perform due to the presence of lateral electronic disequilibrium and steep dose gradients. In stereotactic radiosurgery (SRS), small fields of 6-30 mm in diameter are used. Generally thermoluminescence dosimetry chips, Farmer, Thimble ion chamber,...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1350437
更新日期:2001-03-01 00:00:00
abstract::Part III (oral exam) is the final part of ABR board exam for Diagnostic Medical Physics. In this exam, each of five oral examiners questions the candidate in each of five question categories. Oral exam has unique challenges to the candidate compared with the written exams. The candidate is expected to have not only ad...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4736136
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:Cone-beam CT (CBCT) images contain severe shading artifacts mostly due to scatter. Many algorithms have been proposed to alleviate this problem by data correction on projections. Sophisticated methods have also been designed to further improve the image quality when prior patient information is available. In th...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4736218
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:Hypoxia is one of the most important factors influencing clinical outcome after radiotherapy. Improved knowledge of factors affecting the levels and distribution of oxygen within a tumor is needed. The authors constructed a theoretical 3D model based on histological images to analyze the influence of vessel den...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4773886
更新日期:2013-02-01 00:00:00
abstract:PURPOSE:Several works have recently focused on flattening-filter-free (FFF) beams of linear accelerators of various companies (in particular, Varian and Elekta), but no overview as yet exists for the flattening-filter free 7XU beam (Siemens Artiste). METHODS:Dosimetric properties of the 7XU beam were measured in May a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3703835
更新日期:2012-05-01 00:00:00
abstract:PURPOSE:This article presents a new reconstruction method for 3D imaging using a multiple 360 degrees circular orbit cone beam CT system, specifically a way to combine 3D volumes reconstructed with each orbit. The main goal is to improve the noise performance in the combined image while avoiding cone beam artifacts. M...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3484058
更新日期:2010-10-01 00:00:00
abstract:PURPOSE:Quantitative cone-beam CT (CBCT) imaging is on increasing demand for high-performance image guided radiation therapy (IGRT). However, the current CBCT has poor image qualities mainly due to scatter contamination. Its current clinical application is therefore limited to patient setup based on only bony structure...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3693050
更新日期:2012-04-01 00:00:00
abstract:PURPOSE:In MRI-guided needle interventions, such as biopsies and brachytherapy, tissue deformation caused by needle movement may result in localization errors and thus hamper the outcome of the procedure. Monitoring the local tissue deformation provides the ability to compensate for it, e.g., by increasing the needle i...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3633906
更新日期:2011-10-01 00:00:00
abstract::This paper presents a numerical investigation of the effective point of measurement of thimble ionization chambers in megavoltage photon beams using Monte Carlo simulations with the EGSNRC system. It is shown that the effective point of measurement for relative photon beam dosimetry depends on every detail of the cham...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2201147
更新日期:2006-06-01 00:00:00
abstract::Generating an optimized radiation treatment plan requires understanding the factors affecting tumour control. Mathematical models of tumour dynamics may help in future studies of factors predicting tumor sensitivity to radiotherapy. In this study, a time-dependent differential model, incorporating biological cancer ma...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2965923
更新日期:2008-07-01 00:00:00
abstract:PURPOSE:A preobject grid can reduce and correct scatter in cone beam computed tomography (CBCT). However, half of the signal in each projection is blocked by the grid. A synchronized moving grid (SMOG) has been proposed to acquire two complimentary projections at each gantry position and merge them into one complete pr...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4937934
更新日期:2016-01-01 00:00:00
abstract:PURPOSE:The extensive use of computed tomography (CT) in diagnostic procedures is accompanied by a growing need for more accurate and patient-specific dosimetry techniques. Optically stimulated luminescent dosimeters (OSLDs) offer a potential solution for patient-specific CT point-based surface dosimetry by measuring a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4914398
更新日期:2015-04-01 00:00:00
abstract::The Anisotropic Analytical Algorithm (AAA) of the Varian Eclipse treatment planning system calculates absolute dose for a variety of beam settings including those with an enhanced dynamic wedge (EDW). This algorithm has gone through a number of version updates since it was first released in July 2005. Previous version...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2965929
更新日期:2008-07-01 00:00:00
abstract:PURPOSE:Tumor grading is an important part of breast cancer diagnosis and currently requires biopsy as its standard. Here, the authors investigate quantitative ultrasound parameters in locally advanced breast cancers that can potentially separate tumors from normal breast tissue and differentiate tumor grades. METHODS...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4852875
更新日期:2014-01-01 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:One of the promising options for motion management in radiation therapy (RT) is the use of LINAC-compatible robotic-arm-mounted ultrasound imaging system due to its high soft tissue contrast, real-time capability, absence of ionizing radiation, and low cost. The purpose of this work is to develop a novel deep l...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.13510
更新日期:2019-05-01 00:00:00
abstract:PURPOSE:Modern CT systems adjust X-ray flux accommodating for patient size to achieve certain image noise values. The effectiveness of this adaptation is an important aspect of CT performance and should ideally be characterized in the context of real patient cases. The objective of this study was to characterize CT per...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12172
更新日期:2017-06-01 00:00:00
abstract::Monte Carlo (MC) simulations were performed to estimate brachytherapy dose distributions for Collaborative Ocular Melanoma Study (COMS) eye plaques. Brachytherapy seed models 200, 6711, and CS-1 Rev2 carrying 103Pd, 125I, and 131Cs radionuclides, respectively, were modeled and benchmarked against previously published ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2940604
更新日期:2008-07-01 00:00:00
abstract:PURPOSE:The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and p...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4870387
更新日期:2014-05-01 00:00:00
abstract::The performance of an indirect-detection, active matrix flat-panel imager (FPI) at diagnostic energies is reported in terms of measured and theoretical signal size, noise power spectrum (NPS), and detective quantum efficiency (DQE). Based upon a 1536 x 1920 pixel, 127 microns pitch array of a-Si:H thin-film transistor...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.598243
更新日期:1998-05-01 00:00:00
abstract::The intensity of Compton scattered photons is directly proportional to the electron density of a substance; therefore it is possible to detect changes in electron density by this noninvasive method. The source-detector geometry has been varied to study the effects of geometry on the calculated electron density values,...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595730
更新日期:1985-01-01 00:00:00
abstract::The concept of equivalent uniform dose (EUD) has been suggested as a means to quantitatively consider heterogeneous dose distributions within targets. Tumor cell density/function is typically assumed to be uniform. We herein propose to use 18F-labeled 2-deoxyglucose (FDG) positron emission tomography (PET) tumor imagi...
journal_title:Medical physics
pub_type: 临床试验,杂志文章
doi:10.1118/1.1779372
更新日期:2004-09-01 00:00:00
abstract:PURPOSE:Recent advances in compressed sensing (CS) enable accurate CT image reconstruction from highly undersampled and noisy projection measurements, due to the sparsifiable feature of most CT images using total variation (TV). These novel reconstruction methods have demonstrated advantages in clinical applications wh...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4729837
更新日期:2012-07-01 00:00:00
abstract::Multi-instrument activity estimation and decay correction techniques were developed for radionuclide mixtures, motivated by the desire for accurate quantitation of Tc-94m positron emission tomography (PET) studies. Tc-94m and byproduct Tc isotopes were produced by proton irradiation of enriched Mo-94 and natural Mo ta...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1333411
更新日期:2001-01-01 00:00:00
abstract:PURPOSE:The implementation of an accurate beam model is an integral part of the commissioning of any planning system. This process is especially challenging in the case of IMRT beam models owing to the complexity of small field sizes and MLC leaf-end and tongue-and-groove effects. The question of how to judge the quali...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4735679
更新日期:2012-06-01 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:PURPOSE:This paper presents the application of MAGIC-f gel in a three-dimensional dose distribution measurement and its ability to accurately measure the dose distribution from a tomotherapy unit. METHODS:A prostate intensity-modulated radiation therapy (IMRT) irradiation was simulated in the gel phantom and the treat...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4704496
更新日期:2012-05-01 00:00:00
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:PURPOSE:Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the hi...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4752211
更新日期:2012-10-01 00:00:00
abstract::Quantitation of planar radionuclide images is hampered by structures containing radioactivity which overlie or underlie the organ of interest. The introduction of single photon emission computerized tomography (SPECT) overcame this problem to a large extent and enhanced the contrast of the images. Attenuation of photo...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596684
更新日期:1991-05-01 00:00:00