Abstract：
PURPOSE:The weighted CT dose index (CTDIw ) has been extended for a nominal total collimation width (nT) greater than 40 mm and relies on measurements of CTDIfreeair. The purpose of this work was to compare three methods of measuring CTDIfreeair and subsequent calculations of CTDIw to investigate their clinical appropriateness. METHODS:The CTDIfreeair, for multiple nTs up to 160 mm, was calculated from (1) high-resolution air kerma profiles from a step-and-shoot translation of a liquid ionization chamber (LIC) (considered to be a dosimetric reference), (2) pencil ionization chamber (PIC) measurements at multiple contiguous positions, and (3) air kerma profiles obtained through the continuous translation of a solid-state detector. The resulting CTDIfreeair was used to calculate the CTDIw , per the extended formalism, and compared. RESULTS:The LIC indicated that a 40 mm nT should not be excluded from the extension of the CTDIw formalism. The solid-state detector differed by as much as 8% compared to the LIC. The PIC was the most straightforward method and gave equivalent results to the LIC. CONCLUSIONS:The CTDIw calculated with the latest CTDI formalism will differ most for 160 mm nTs (e.g., whole-organ perfusion or coronary CT angiography) compared to the previous CTDI formalism. Inaccuracies in the measurement of CTDIfreeair will subsequently manifest themselves as erroneous calculations of the CTDIw , for nTs greater than 40 mm, with the latest CTDI formalism. The PIC was found to be the most clinically feasible method and was validated against the LIC.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Bujila R,Kull L,Danielsson M,Andersson Jdoi
10.1002/acm2.12363subject
Has Abstractpub_date
2018-07-01 00:00:00pages
281-289issue
4issn
1526-9914journal_volume
19pub_type
杂志文章abstract：:The aim of this work is to evaluate the performance of a commercial brachytherapy treatment planning system (TPS) with TG-43 Vendors Input Data (VID), analyze possible discrepancies with respect to a proper reference source and its implications for standard treatments, and judge the effectiveness of certain widespread...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i4.4730
更新日期：2015-07-08 00:00:00
abstract：:High dose rate (HDR) brachytherapy often involves optimization routines to calculate the dwell times and positions of a radioactive source along specified applicator paths. These routines optimize the dwells in such a way as to deliver the prescribed dose at one or more points while satisfying various constraints. The...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v4i2.2530
更新日期：2003-04-01 00:00:00
abstract：PURPOSE:This study aimed to evaluate dosimetric differences of intensity-modulated radiation therapy (IMRT) in target and normal tissues after breast-conserving surgery. METHODS:IMRT five-field plan I, IMRT six-field plan II, and field-in-field-direct machine parameter optimization-IMRT plan III were designed for each...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12287
更新日期：2018-05-01 00:00:00
abstract：:This article compares two algorithms for determining beam weights and wedge filters for conformal treatment planning. One algorithm, which is based on dose-gradient analysis, provides analytic formulas for determining beam weights, wedge angles, and collimator angles (i.e., wedge orientations) so that the dose distrib...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v3i3.2562
更新日期：2002-07-01 00:00:00
abstract：:The purpose of this study was to implement full/half bowtie filter models in a com-mercial treatment planning system (TPS) to calculate kilovoltage (kV) cone-beam CT (CBCT) doses of Varian On-Board Imager (OBI) kV X-ray imaging system. The full/half bowtie filter models were created as compensators in Pinnacle TPS usi...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.5988
更新日期：2016-03-08 00:00:00
abstract：:Studies have shown that source dwells within Varian's HDR CT/MR compatible ring applicators can deviate from intended positions by several millimeters. Quantifying this offset is an important part of commissioning. The aims of this study were to: 1) determine the reproducibility of the offset, 2) study the interobserv...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v12i4.3447
更新日期：2011-11-15 00:00:00
abstract：PURPOSE:Prescription practice in SRS plans for brain tumors differs significantly for different modalities. In this retrospective study, the strategies to optimize SRS plans for brain tumors with volumetric arc therapy (VMAT) were presented. METHODS:Fifty clinically treated cases were stratified by the maximum target ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12818
更新日期：2020-03-01 00:00:00
abstract：:Stereotactic body radiotherapy (SBRT) of lung tumors via the ring-mounted Halcyon Linac, a fast kilovoltage cone beam CT-guided treatment with coplanar geometry, a single energy 6MV flattening filter free (FFF) beam and volumetric modulated arc therapy (VMAT) is a fast, safe, and feasible treatment modality for select...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.13146
更新日期：2020-12-20 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
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：:This report provides guidelines for a peer review process between two clinical radiation oncology physicists. While the Task Group's work was primarily focused on ensuring timely and productive independent reviews for physicists in solo practice, these guidelines may also be appropriate for physicists in a group setti...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章,实务指引
doi：10.1120/jacmp.v6i4.2142
更新日期：2005-10-01 00:00:00
abstract：BACKGROUND AND PURPOSE:The purpose of this study of pancreatic cancer patients treated with respiratory-guided stereotactic body radiotherapy (SBRT) on a standard linac was to investigate (a) the intrafractional relationship change (IRC) between a breathing signal and the tumor position, (b) the impact of IRC on the de...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12841
更新日期：2020-03-01 00:00:00
abstract：PURPOSE:To establish a streamlined end-to-end test of a 6 degrees-of-freedom (6DoF) robotic table using a 3D printed phantom for periodic quality assurance. METHODS:A 3D printed phantom was fabricated with translational and rotational offsets and an imbedded central ball-bearing (BB). The phantom underwent each step o...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12227
更新日期：2018-01-01 00:00:00
abstract：:Intraoperative electron radiation therapy (IOERT) cannot usually benefit, as conventional external radiotherapy, from software systems of treatment planning based on computed tomography and from common dose verify procedures. For this reason, in vivo film dosimetry (IVFD) proves to be an effective methodology to evalu...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i1.5065
更新日期：2014-01-08 00:00:00
abstract：PURPOSE:Targeting and tracking of central lung tumors may be feasible on the Elekta MRI-linac (MRL) due to the soft-tissue visualization capabilities of MRI. The purpose of this work is to develop a novel treatment planning methodology to simulate tracking of central lung tumors with the MRL and to quantify the benefit...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12233
更新日期：2018-01-01 00:00:00
abstract：:The image-guided radiotherapy technique (IGRT) makes use of imaging devices to verify the positions of the target volume and organs at risk during the treatment sessions. In this work we evaluate the image quality provided by an imaging system based on a kilovoltage cone-beam CT, and explore its ability to perform IGR...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v14i1.3888
更新日期：2013-01-07 00:00:00
abstract：:The analysis of dynamic multileaf collimator (MLC) positions for the delivered intensity-modulated radiotherapy (IMRT) plans is crucial in that it may capture dose delivery problems otherwise difficult to observe and quantify in the conventional dosimetric measurements with film or with an ionization chamber. In some ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v6i2.2076
更新日期：2005-04-01 00:00:00
abstract：:Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross-sectional library for the purpose of simulating different elem...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.5797
更新日期：2016-03-08 00:00:00
abstract：PURPOSE:To assess the impact of isocenter shifts due to linac gantry and table rotation during cranial stereotactic radiosurgery on D98 , target volume coverage (TVC), conformity (CI), and gradient index (GI). METHODS:Winston-Lutz (WL) checks were performed on two Elekta Synergy linacs. A stereotactic quality assuranc...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12854
更新日期：2020-05-01 00:00:00
abstract：:The American Association of Physicists in Medicine Task Group 36 (AAPM TG-36) data can be used to estimate peripheral dose (PD) distributions outside the primary radiation field. However, the report data does not apply to linear accelerators equipped with a multileaf collimator (MLC) and universal wedge (UW). Tertiary...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v3i4.2554
更新日期：2002-10-01 00:00:00
abstract：:We report on initial patient studies to evaluate the performance of a commercial respiratory gating radiotherapy system. The system uses a breathing monitor, consisting of a video camera and passive infrared reflective markers placed on the patient's thorax, to synchronize radiation from a linear accelerator with the ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v2i4.2596
更新日期：2001-10-01 00:00:00
abstract：:Dental amalgams are a common source of artifacts in head and neck (HN) images. Commercial artifact reduction techniques have been offered, but are substantially ineffectual at reducing artifacts from dental amalgams, can produce additional artifacts, provide inaccurate HU information, or require extensive computation ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12922
更新日期：2020-08-01 00:00:00
abstract：:The longitudinal coverage of a LINAC-mounted CBCT scan is limited to the corresponding dimensional limits of its flat panel detector, which is often shorter than the length of the treatment field. These limits become apparent when fields are designed to encompass wide regions, as when providing nodal coverage. Therefo...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v13i4.3796
更新日期：2012-07-05 00:00:00
abstract：:Endorectal balloons (ERBs) are routinely used in prostate proton radiation therapy to immobilize the prostate and spare the rectal wall. Rectal gas can distend the rectum and displace the prostate even in the presence of ERBs. The purpose of this work was to quantify the effects an ERB with a passive gas release condu...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v13i5.3945
更新日期：2012-09-06 00:00:00
abstract：:Quality control (QC) of CT scanners is important to evaluate image quality and radiation dose. Different QC phantoms for testing image quality parameters on CT are commercially available, and Catphan phantoms are widely used for this purpose. More data from measured image quality parameters on CT are necessary to asse...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12186
更新日期：2017-11-01 00:00:00
abstract：:Optimal choice of beam energy in radiation therapy is easy in many well-documented cases, but less obvious in some others. Low-energy beams may provide better conformity around the target than their high-energy counterparts due to reduced lateral scatter, but they also contribute to overdosage of peripheral normal tis...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v10i4.3012
更新日期：2009-09-03 00:00:00
abstract：:In radiation therapy, a secondary independent dose verification is an important component of a quality control system. Mobius3D calculates three-dimensional (3D) patient dose using reference beam data and a collapsed cone convolution algorithm and analyzes dose-volume histogram automatically. There are currently no pu...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12572
更新日期：2019-05-01 00:00:00
abstract：:The purpose of this study is to determine whether organ sparing and target coverage can be simultaneously maintained for pencil beam scanning (PBS) proton therapy treatment of thoracic tumors in the presence of motion, stopping power uncertainties, and patient setup variations. Ten consecutive patients that were previ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i6.5678
更新日期：2015-11-08 00:00:00
abstract：:This study aimed to verify the accuracy of half-value layer (HVL) measured using the new copper pipe method with the CT ionization chamber while the X-ray tube is rotating and to compare it with the conventional nonrotating method and Monte Carlo simulation method based on the actual measurement and geometry of the ne...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12780
更新日期：2019-12-01 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
