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, a high-definition MLC (HD120 MLC) with 2.5 mm central leaves, a 6D robotic couch, an optical guidance positioning system, as well as X-ray-based image guidance tools to provide high accuracy radiation delivery for stereotactic radiosurgery and stereotactic body radiation therapy procedures. We have performed extensive tests for each of the components, and analyzed the clinical data collected in our clinic. We present technical guidelines in this report focusing on methods for: (1) efficient and accurate beam data collection for commissioning treatment planning systems, including small field output measurements conducted using a wide range of detectors; (2) commissioning tests for the HD120 MLC; (3) data collection for the baseline characteristics of the on-board imager (OBI) and ExacTrac X-ray (ETX) image guidance systems in conjunction with the 6D robotic couch; and (4) end-to-end testing of the entire clinical process. Established from our clinical experience thus far, recommendations are provided for accurate and efficient use of the OBI and ETX localization systems for intra- and extracranial treatment sites. Four results are presented. (1) Basic beam data measurements: Our measurements confirmed the necessity of using small detectors for small fields. Total scatter factors varied significantly (30% to approximately 62%) for small field measurements among detectors. Unshielded stereotactic field diode (SFD) overestimated dose by ~ 2% for large field sizes. Ion chambers with active diameters of 6 mm suffered from significant volume averaging. The sharpest profile penumbra was observed for the SFD because of its small active diameter (0.6 mm). (2) MLC commissioning: Winston Lutz test, light/radiation field congruence, and Picket Fence tests were performed and were within criteria established by the relevant task group reports. The measured mean MLC transmission and dynamic leaf gap of 6 MV SRS beam were 1.17% and 0.36 mm, respectively. (3) Baseline characteristics of OBI and ETX: The isocenter localization errors in the left/right, posterior/anterior, and superior/inferior directions were, respectively, -0.2 ± 0.2 mm, -0.8 ± 0.2 mm, and -0.8 ± 0.4 mm for ETX, and 0.5 ± 0.7 mm, 0.6 ± 0.5 mm, and 0.0 ± 0.5 mm for OBI cone-beam computed tomography. The registration angular discrepancy was 0.1 ± 0.2°, and the maximum robotic couch error was 0.2°. (4) End-to-end tests: The measured isocenter dose differences from the planned values were 0.8% and 0.4%, measured respectively by an ion chamber and film. The gamma pass rate, measured by EBT2 film, was 95% (3% DD and 1 mm DTA). Through a systematic series of quantitative commissioning experiments and end-to-end tests and our initial clinical experience, described in this report, we demonstrate that the NTX is a robust system, with the image guidance and MLC requirements to treat a wide variety of sites - in particular for highly accurate delivery of SRS and SBRT-based treatments.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Kim J,Wen N,Jin JY,Walls N,Kim S,Li H,Ren L,Huang Y,Doemer A,Faber K,Kunkel T,Balawi A,Garbarino K,Levin K,Patel S,Ajlouni M,Miller B,Nurushev T,Huntzinger C,Schulz R,Chetty IJ,Movsas B,Ryu Sdoi
10.1120/jacmp.v13i3.3729subject
Has Abstractpub_date
2012-05-10 00:00:00pages
3729issue
3issn
1526-9914journal_volume
13pub_type
杂志文章abstract::Magnetic Resonance Imaging (MRI) simulation differs from diagnostic MRI in purpose, technical requirements, and implementation. We propose a semiautomatic method for image acceptance and commissioning for the scanner, the radiofrequency (RF) coils, and pulse sequences for an MRI simulator. The ACR MRI accreditation la...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12311
更新日期:2018-05-01 00:00:00
abstract::The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i4.6218
更新日期:2016-07-08 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::PET/CT imaging could improve delineation of rectal carcinoma gross tumor volume (GTV) and reduce interobserver variability. The objective of this work was to compare various functional volume delineation algorithms. We enrolled 31 consecutive patients with locally advanced rectal carcinoma. The FDG PET/CT and the high...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i5.4696
更新日期:2014-09-08 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
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doi:10.1120/jacmp.v17i2.5988
更新日期:2016-03-08 00:00:00
abstract::Our institution performs in vivo verification measurement for each of our total body irradiation (TBI) patients with optically stimulated luminescent dosimeters (OSLD). The lung block verification measurements were commonly higher than expected. The aim of this work is to understand this discrepancy and improve the ac...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i3.6128
更新日期:2016-05-08 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::Stereotactic body radiation therapy (SBRT) has been increasingly used as an efficacious treatment modality for early-stage non-small cell lung cancer. The accuracy of dose calculations is compromised due to the presence of inhomogeneity. For the purpose of a consistent prescription, radiation doses were calculated wit...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i2.4011
更新日期:2013-03-04 00:00:00
abstract::The purpose of this study was to quantify the intrafraction motion of pediatric patients with brain tumors during radiation therapy and investigate any correlation between motion, use of general anesthesia, and daily treatment duration. 100 pediatric patients with a mean age of 8.5 years (range: 1.0 to 17.8) were incl...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i4.3609
更新日期:2011-11-15 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12919
更新日期:2020-08-01 00:00:00
abstract:INTRODUCTION:Designing a radiation plan that optimally delivers both target coverage and normal tissue sparing is challenging. There are limited tools to determine what is dosimetrically achievable and frequently the experience of the planner/physician is relied upon to make these determinations. PlanIQ software provid...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12165
更新日期:2017-09-01 00:00:00
abstract::True 3D CT dataset for treatment planning of an oversized patient is difficult to acquire due to the bore size and field of view (FOV) reconstruction. This project aims to provide a simple approach to reconstruct true CT data for oversize patients using CT scanner with limited FOV by acquiring double partial CT (left ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i2.3629
更新日期:2012-03-08 00:00:00
abstract::The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the mo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i5.4335
更新日期:2013-09-06 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:To investigate the daily setup, interfraction motion, variability in the junction areas, and dosimetric effect in craniospinal irradiation (CSI) patients. METHODS:Fifteen CSI patients who had undergone split-field IMRT were followed in the study. Previous, middle, and posttreatment, each target volume position...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12909
更新日期:2020-08-01 00:00:00
abstract:PURPOSE:The aim of this study was to develop and assess the performance of supervised machine learning technique to classify magnetic resonance imaging (MRI) voxels as cancerous or noncancerous using noncontrast multiparametric MRI (mp-MRI), comprised of T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12992
更新日期:2020-10-01 00:00:00
abstract::Radiochromic film has become an important tool to verify dose distributions in highly conformal radiation therapy such as IMRT. Recently, a new generation of these films, EBT3, has become available. EBT3 has the same composition and thickness of the sensitive layer of the previous EBT2 films, but its symmetric layer c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i2.4111
更新日期:2013-03-04 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: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::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...
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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:OBJECTIVES:To evaluate the influence of MRI scanning parameters on texture analysis features. METHODS:Publicly available data from the Reference Image Database to Evaluate Therapy Response (RIDER) project sponsored by The Cancer Imaging Archive included MRIs on a phantom comprised of 18 25-mm doped, gel-filled tubes, ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12482
更新日期:2018-11-01 00:00:00
abstract::The purpose of this study is to find the uncertainties in the reconstruction of MR compatible ring-tandem intracavitary applicators of high-dose rate image-based brachytherapy treatment planning using rigid registration of 3D MR and CT image fusion. Tandem and ring reconstruction in MR image based brachytherapy planni...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i2.4206
更新日期:2014-03-06 00:00:00
abstract::Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in-plane (x,y) and z-axis (slice thickness) inf...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6294
更新日期:2016-09-08 00:00:00
abstract::For most computed tomography (CT) simulators, radiation therapists must remove the flat couch top to perform daily CT quality assurance (QA), and then use separate tools to perform localization-laser QA. This process wastes time and effort and creates the opportunity for accidents to occur. In this study, we tested a ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i3.2844
更新日期:2009-06-17 00:00:00
abstract::The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system's behavior in simple geometries...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i3.4636
更新日期:2015-05-08 00:00:00
abstract::A spreadsheet-based model for economically characterizing the operation of a radiation treatment program has been used to perform a quantitative financial analysis of scheduled and unscheduled downtime. The incremental cost of downtime is broken down into three categories: remuneration of in-house or third party servi...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v1i2.2647
更新日期:2000-04-01 00:00:00
abstract::This study evaluated the extent of improvement in dose predication accuracy achieved by the Fast Monte Carlo algorithm (MC) compared to the Ray Tracing algorithm (RAT) in stereotactic body radiotherapy (SBRT) of non-small cell lung cancer (NSCLC), and how their differences were influenced by the tumor site and size. T...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i5.4280
更新日期:2013-09-06 00:00:00
abstract::The aim of this study is to compare the dosimetric characteristics of robotic and conventional linac-based SBRT techniques for lung cancer, and to provide planning guidance for each modality. Eight patients who received linac-based SBRT were retrospectively included in this study. A dose of 60 Gy given in three fracti...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i3.3223
更新日期:2010-06-29 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::Chest wall radiation therapy treatment delivery was monitored using a 5 mm thick radiochromic poly(vinyl alcohol) cryogel that also provided buildup material. The cryogels were used to detect positioning errors and measure the impact of shifts for a chest wall treatment that was delivered to a RANDO phantom. The phant...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6148
更新日期:2016-09-08 00:00:00