Abstract：
INTRODUCTION:The purpose of this study was to present the optimization process of CT parameters to reduce patient exposure during bone SPECT/CT without affecting the quality of SPECT images with attenuation correction (AC). MATERIAL AND METHODS:A fillable phantom reflecting realistic bone scintigraphy conditions was developed and acquired on an AnyScan SC. SPECT/CT scans were carried out with different x-ray tube current values (10, 20, 30, 40, 50, 60, 70, 90, 110, 130, 150, and 200 mA) at three different high-voltage values (80, 100, and 120 kV). The contrast (C) and coefficients of variation (CV) in the SPECT images as well as the signal-to-noise ratio (SNR) and noise (SDCT ) in the CT images with CTDIvol were measured. An optimal acquisition protocol that obtained SPECT/CT images with no artifacts on both CT and SPECT images, acceptable C, SNR, CV, and SDCT values, and the largest reduction in patient exposure compared to the reference acquisition procedure was sought. RESULTS:The optimal set of parameters for bone SPECT/CT was determined based on a phantom study. It has been implemented in clinical practice. Two groups of patients were examined according to the baseline and optimized protocols, respectively. The new SPECT/CT protocol substantially reduced patients' radiation exposure compared to the old protocol while maintaining the required diagnostic quality of SPECT and CT images. CONCLUSIONS:In the study, we present a methodology that finds a compromise between diagnostic information and patient exposure during bone SPECT/CT procedures.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Tulik M,Tulik P,Kowalska Tdoi
10.1002/acm2.13069subject
Has Abstractpub_date
2020-10-27 00:00:00issn
1526-9914pub_type
杂志文章abstract：:TomoEDGE is an advanced delivery form of tomotherapy which uses a dynamic secondary collimator. This plan comparison study describes the new features, their clinical applicability, and their effect on plan quality and treatment speed. For the first 45 patients worldwide that were scheduled for a treatment with TomoEdg...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i2.4964
更新日期：2015-03-08 00:00:00
abstract：:We describe a method for independently verifying the dose distributions from pre- and post-implant brachytherapy source distributions. Monte Carlo calculations have been performed to characterize the three-dimensional dose distribution in water phantom from a low-energy brachytherapy source. The calculations are perfo...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v4i1.2543
更新日期：2003-01-01 00:00:00
abstract：PURPOSE:We introduce an automated, quantitative image analysis package for gamma camera and single photon emission computed tomography quality control. Our focus was to produce consistent methods that are feasible in clinical settings and use standard phantoms. METHODS:Four gamma cameras were used to acquire planar im...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.13057
更新日期：2020-11-03 00:00:00
abstract：PURPOSE:Elekta XVI 5.0 allows for four-dimensional cone beam computed tomography (4D CBCT) image acquisition during treatment delivery to monitor intrafraction motion. These images can have poorer image quality due to undersampling of kV projections and treatment beam MV scatter effects. We determine if a universal int...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12755
更新日期：2019-12-01 00:00:00
abstract：INTRODUCTION:A previous pilot study has demonstrated the feasibility of a novel image-based approach for remote dosimetric auditing of clinical trials. The approach uses a model to convert in-air acquired intensity modulated radiotherapy (IMRT) images to delivered dose inside a virtual phantom. The model was developed ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12521
更新日期：2019-01-01 00:00:00
abstract：PURPOSE:The aim of the current study was to evaluate the backscatter dose and energy spectrum from the Lipiodol with flattening filter (FF) and flattening filter-free (FFF) beams. Moreover, the backscatter range, that was defined as the backscatter distance (BD) are revealed. METHODS:6 MVX FF and FFF beams were delive...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12560
更新日期：2019-06-01 00:00:00
abstract：:A custom-made computer program, SWIMRT, to construct "multileaf collimator (MLC) machine" file for intensity-modulated radiotherapy (IMRT) fluence maps was developed using MATLAB and the sliding window algorithm. The user can either import a fluence map with a graphical file format created by an external treatment-pla...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v7i2.2231
更新日期：2006-05-25 00:00:00
abstract：:Atlas-based autosegmentation is an established tool for segmenting structures for CT-planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI-based, atlas-based autosegmentation for organs at risk (OAR) and lymph node ...
journal_title：Journal of applied clinical medical physics
pub_type： 临床试验,杂志文章
doi：10.1120/jacmp.v17i4.6051
更新日期：2016-07-08 00:00:00
abstract：:Documentation is a required component of a residency program, but can be difficult to collect and disseminate, resulting in minimal utilization by residents and faculty. The purpose of this work is to adapt a commercially-available Web-based medical residency management system to improve the learning experience by eff...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v15i6.4866
更新日期：2014-11-08 00:00:00
abstract：:This work introduces a new technology for electron intensity modulation, which uses small area island blocks within the collimating aperture and small area island apertures in the collimating insert. Due to multiple Coulomb scattering, electrons contribute dose under island blocks and lateral to island apertures. By s...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12163
更新日期：2017-11-01 00:00:00
abstract：:We conducted a metrological evaluation of the dosimetric impact due to the polysulfone cap used with the Fletcher-Williamson (FW) colpostat for 192Ir high-dose rate and pulsed-dose rate intracavitary brachytherapy using Monte Carlo simulations. Polysulfone caps with diameter of 30 mm, 25 mm, 20 mm, and 16 mm (mini-ovo...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v11i1.3146
更新日期：2010-01-28 00:00:00
abstract：:Remote afterloading devices used for high-dose-rate (HDR) brachytherapy may be supplied with different sources, and these sources typically have differing initial source strengths. In addition, the proposed frequency for source changes may also vary, depending upon the source type. Dosimetric parameters unique to each...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v14i6.4239
更新日期：2013-11-04 00:00:00
abstract：:This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v10i2.2867
更新日期：2009-04-22 00:00:00
abstract：:Highly attenuating radiation treatment couches are no longer useful in the present era of radiotherapy utilizing IMRT and IGRT. Carbon fibers couch tops with its high tensile strength and low density present a useful alternative. The objective of the current study was to quantify the attenuation of megavoltage photons...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v10i3.2979
更新日期：2009-06-02 00:00:00
abstract：:Detection and accurate quantification of treatment delivery errors is important in radiation therapy. This study aims to evaluate the accuracy of DVH based QA in quantifying delivery errors. Eighteen previously treated VMAT plans (prostate, H&N, and brain) were randomly chosen for this study. Conventional IMRT deliver...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i5.6344
更新日期：2016-09-08 00:00:00
abstract：:A quality assurance (QA) procedure was developed to evaluate the congruence between the cone-beam computed tomography (CBCT) image center and the radiation isocenter on a Varian Trilogy linac. In contrast to the published QA procedures, this method did not require a ball bearing (BB) phantom to be placed exactly at th...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v11i4.3297
更新日期：2010-07-02 00:00:00
abstract：:A thorax phantom was used to assess radiotherapy dose deviations induced by respiratory motion of the target volume. Both intensity modulated and static, non-modulated treatment plans were planned on CT scans of the phantom. The plans were optimized using various CT reconstructions, to investigate whether they had an ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12847
更新日期：2020-04-01 00:00:00
abstract：:The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth-dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small fi...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v12i1.3267
更新日期：2010-10-04 00:00:00
abstract：:Small field dosimetry is a challenging task. The difficulties of small field measurements, particularly stereotactic field size measurements, are highlighted by the large interinstitution variability that can be observed for circular cone collimator commissioning measurements. We believe the best way to improve the co...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v14i6.4493
更新日期：2013-11-04 00:00:00
abstract：:The design concept and dosimetric characteristics of a new applicator system for intraoperative radiation therapy (IORT) are presented in this work. A new hard-docking commercial system includes polymethylmethacrylate (PMMA) applicators with different diameters and applicator end angles and a set of secondary lead col...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v11i4.3244
更新日期：2010-07-19 00:00:00
abstract：:A new calculation algorithm has been developed for independently verifying doses calculated by the TomoTherapy Hi.Art treatment planning system (TPS). The algorithm is designed to confirm the dose to a point in a high dose, low dose-gradient region. Patient data used by the algorithm include the radiological depth to ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v10i1.2772
更新日期：2009-02-05 00:00:00
abstract：:We retrospectively generated IMRT plans for 14 NSCLC patients who had experienced grade 2 or 3 esophagitis (CTCAE version 3.0). We generated 11-beam and reduced esophagus dose plan types to compare changes in the volume and length of esophagus receiving doses of 50, 55, 60, 65, and 70 Gy. Changes in planning target vo...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v14i4.4248
更新日期：2013-07-08 00:00:00
abstract：:Two patients with multiple lung metastases (≥ 5) were treated using frameless stereotactic body radiation therapy (SBRT) on an Elekta Axesse linear accelerator equipped with an interdigitation-capable multileaf collimator and four-dimensional cone-beam CT (4D CBCT). The technique and the early clinical outcomes were e...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v15i4.4737
更新日期：2014-07-08 00:00:00
abstract：:A microchamber, PTW Pinpoint 31006, was used to measure transverse beam profiles for an Elekta Gamma Knife, Model B, and compared with profiles measured with film dosimetry. The microchamber sensitive volume has a diameter of 2 mm, which is smaller than the gamma knife beams, and a length of 5 mm. The chamber was moun...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v3i1.2587
更新日期：2002-01-01 00:00:00
abstract：PURPOSE:To report our early experiences with failure mode and effects analysis (FMEA) in a community practice setting. METHODS:The FMEA facilitator received extensive training at the AAPM Summer School. Early efforts focused on department education and emphasized the need for process evaluation in the context of high ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12190
更新日期：2017-11-01 00:00:00
abstract：PURPOSE:To quantify the effects of combining layer-based repainting and respiratory gating as a strategy to mitigate the dosimetric degradation caused by the interplay effect between a moving target and dynamic spot-scanning proton delivery. METHODS:An analytic routine modeled three-dimensional dose distributions of p...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12702
更新日期：2019-09-01 00:00:00
abstract：:Many head-and-neck cancer (HNC) patients treated with radiotherapy suffer significant anatomical changes due to tumor shrinkage or weight loss. The purpose of this study was to assess dose changes over target volumes and organs at risk during intensity-modulated radiotherapy for HNC patients. Sixteen HNC IMRT patients...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v13i6.3723
更新日期：2012-11-08 00:00:00
abstract：PURPOSE:To present an open-source software (https://github.com/CHUSRadOncPhys/FluoMV) for monitoring intrafraction motion that is based on the visualization of superimposed contours of projected region-of-interests from DICOM RTSTRUCT files on cine-MV images acquired and displayed in real-time during radiation therapy ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12940
更新日期：2020-08-01 00:00:00
abstract：:The purpose of this study was to perform comprehensive measurements and testing of a Novalis Tx linear accelerator, and to develop technical guidelines for com-missioning from the time of acceptance testing to the first clinical treatment. The Novalis Tx (NTX) linear accelerator is equipped with, among other features,...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v13i3.3729
更新日期：2012-05-10 00:00:00
abstract：PURPOSE:This study evaluates the clinical use of the RUBY modular QA phantom for linac QA to validate the integrity of IGRT workflows including the congruence of machine isocenter, imaging isocenter, and room lasers. The results have been benchmarked against those obtained with widely used systems. Additionally, the RU...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.13006
更新日期：2020-10-01 00:00:00
