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Ma Y, Mou X, Beeraka NM, Guo Y, Liu J, Dai J, Fan R. Machine Log File and Calibration Errors-based Patient-specific Quality Assurance (QA) for Volumetric Modulated Arc Therapy (VMAT). Curr Pharm Des 2023; 29:2738-2751. [PMID: 37916622 DOI: 10.2174/0113816128226519231017050459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 05/19/2023] [Accepted: 06/05/2023] [Indexed: 11/03/2023]
Abstract
INTRODUCTION Dose reconstructed based on linear accelerator (linac) log-files is one of the widely used solutions to perform patient-specific quality assurance (QA). However, it has a drawback that the accuracy of log-file is highly dependent on the linac calibration. The objective of the current study is to represent a new practical approach for a patient-specific QA during Volumetric modulated arc therapy (VMAT) using both log-file and calibration errors of linac. METHODS A total of six cases, including two head and neck neoplasms, two lung cancers, and two rectal carcinomas, were selected. The VMAT-based delivery was optimized by the TPS of Pinnacle^3 subsequently, using Elekta Synergy VMAT linac (Elekta Oncology Systems, Crawley, UK), which was equipped with 80 Multi-leaf collimators (MLCs) and the energy of the ray selected at 6 MV. Clinical mode log-file of this linac was used in this study. A series of test fields validate the accuracy of log-file. Then, six plans of test cases were delivered and log-file of each was obtained. The log-file errors were added to the corresponding plans through the house script and the first reconstructed plan was obtained. Later, a series of tests were performed to evaluate the major calibration errors of the linac (dose-rate, gantry angle, MLC leaf position) and the errors were added to the first reconstruction plan to generate the second reconstruction plan. At last, all plans were imported to Pinnacle and recalculated dose distribution on patient CT and ArcCheck phantom (SUN Nuclear). For the former, both target and OAR dose differences between them were compared. For the latter, γ was evaluated by ArcCheck, and subsequently, the surface dose differences between them were performed. RESULTS Accuracy of log-file was validated. If error recordings in the log file were only considered, there were four arcs whose proportion of control points with gantry angle errors more than ± 1°larger than 35%. Errors of leaves within ± 0.5 mm were 95% for all arcs. The distinctness of a single control point MU was bigger, but the distinctness of cumulative MU was smaller. The maximum, minimum, and mean doses for all targets were distributed between -6.79E-02-0.42%, -0.38-0.4%, 2.69E-02-8.54E-02% respectively, whereas for all OAR, the maximum and mean dose were distributed between -1.16-2.51%, -1.21-3.12% respectively. For the second reconstructed dose: the maximum, minimum, and mean dose for all targets was distributed between 0.0995~5.7145%, 0.6892~4.4727%, 0.5829~1.8931% separately. Due to OAR, maximum and mean dose distribution was observed between -3.1462~6.8920%, -6.9899~1.9316%, respectively. CONCLUSION Patient-specific QA based on the log-file could reflect the accuracy of the linac execution plan, which usually has a small influence on dose delivery. When the linac calibration errors were considered, the reconstructed dose was closer to the actual delivery and the developed method was accurate and practical.
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Affiliation(s)
- Yangguang Ma
- Department of Radiation Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
- School of Information and Communications Engineering, Xi'AN Jiaotong University, Xi'an 710049, China
| | - Xuanqin Mou
- School of Information and Communications Engineering, Xi'AN Jiaotong University, Xi'an 710049, China
| | - Narasimha M Beeraka
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER), Anantapuramu, Chiyyedu, Andhra Pradesh 515721, India
- Department of Human Anatomy, I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Str., Moscow 119991, Russia
| | - Yuexin Guo
- Department of Radiation Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Junqi Liu
- Department of Radiation Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Jianrong Dai
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100021, China
| | - Ruitai Fan
- Department of Radiation Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
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Hanley J, Dresser S, Simon W, Flynn R, Klein EE, Letourneau D, Liu C, Yin FF, Arjomandy B, Ma L, Aguirre F, Jones J, Bayouth J, Holmes T. AAPM Task Group 198 Report: An implementation guide for TG 142 quality assurance of medical accelerators. Med Phys 2021; 48:e830-e885. [PMID: 34036590 DOI: 10.1002/mp.14992] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/16/2021] [Accepted: 04/28/2021] [Indexed: 11/11/2022] Open
Abstract
The charges on this task group (TG) were as follows: (a) provide specific procedural guidelines for performing the tests recommended in TG 142; (b) provide estimate of the range of time, appropriate personnel, and qualifications necessary to complete the tests in TG 142; and (c) provide sample daily, weekly, monthly, or annual quality assurance (QA) forms. Many of the guidelines in this report are drawn from the literature and are included in the references. When literature was not available, specific test methods reflect the experiences of the TG members (e.g., a test method for door interlock is self-evident with no literature necessary). In other cases, the technology is so new that no literature for test methods was available. Given broad clinical adaptation of volumetric modulated arc therapy (VMAT), which is not a specific topic of TG 142, several tests and criteria specific to VMAT were added.
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Affiliation(s)
- Joseph Hanley
- Princeton Radiation Oncology, Monroe, New Jersey, 08831, USA
| | - Sean Dresser
- Winship Cancer Institute, Radiation Oncology, Emory University, Atlanta, Georgia, 30322, USA
| | | | - Ryan Flynn
- Department of Radiation Oncology, University of Iowa, Iowa City, Iowa, 52242, USA
| | - Eric E Klein
- Brown university, Rhode Island Hospital, Providence, Rhode Island, 02905, USA
| | | | - Chihray Liu
- University of Florida, Gainesville, Florida, 32610-0385, USA
| | - Fang-Fang Yin
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, 27710, USA
| | - Bijan Arjomandy
- Karmanos Cancer Institute at McLaren-Flint, Flint, Michigan, 48532, USA
| | - Lijun Ma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, 94143-0226, USA
| | | | - Jimmy Jones
- Department of Radiation Oncology, The University of Colorado Health-Poudre Valley, Fort Collins, Colorado, 80525, USA
| | - John Bayouth
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, 53792-0600, USA
| | - Todd Holmes
- Varian Medical Systems, Palo Alto, California, 94304, USA
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Li Q, Gu W, Mu J, Yin W, Gao M, Mo J, Pei H. Collimator rotation in volumetric modulated arc therapy for craniospinal irradiation and the dose distribution in the beam junction region. Radiat Oncol 2015; 10:235. [PMID: 26584626 PMCID: PMC4653929 DOI: 10.1186/s13014-015-0544-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/27/2015] [Indexed: 11/10/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the role of beam collimator rotation in Volumetric Modulated Arc Therapy (VMAT) for craniospinal irradiation (CSI), and the impact on dose distribution in the beam junctions. METHODS Six adult patients were selected for the study. Six VMAT plans with different collimator angles were generated for each patient. The patients were treated in supine position with two beam isocenters. The plans were evaluated by analysis of Dose-Volume Histogram (DVHs) data for planning target volume (PTV) and organs at risk (OAR), and conformity index (CI) and homogeneity index (HI) for the target. Dose distributions in the beam junctions were examined carefully and experimentally validated in phantom, with measurement using an ion chamber array and film. RESULTS The mean values of HI and CI for the plans with different beam collimator angles were not significantly different. The numbers of segments, monitor units (MUs) and the delivery time of the plans with 45° beam collimator were obviously higher than those in plans with other beam collimator angles. When collimator angle for both sets of beams were set at 0°, there was a 1 mm low dose gap measured in the junction region. CONCLUSIONS By setting the collimator angle to 45°, only two isocenters were needed for the treatment of a target with the length up to 90 cm. The HI and CI of the plans were almost the same, regardless if the collimator angles were at 0°. The collimator angles for at least one set of beams should be off 0° in order to avoid a dose gap in the beam junction region.
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Affiliation(s)
- Qilin Li
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Wendong Gu
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Jinming Mu
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Wenming Yin
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Min Gao
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Juncong Mo
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
| | - Honglei Pei
- Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou City, 185 Ju Qian Jie, Changzhou City, 213003, Jiangsu Province, China.
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Carosi A, Ingrosso G, Ponti E, Tolu B, Murgia A, di Cristino D, Santoni R. Dosimetric effect of Elekta Beam modulator micromultileaf in three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for prostate cancer. Med Dosim 2014; 39:180-4. [PMID: 24433833 DOI: 10.1016/j.meddos.2013.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 10/29/2013] [Accepted: 12/09/2013] [Indexed: 10/25/2022]
Abstract
The purpose of this study is to analyze the dosimetric effect of Elekta Beam Modulator in 3-dimensional conformal radiation therapy (3DCRT) and in intensity-modulated radiation therapy (IMRT) for localized prostate cancer. We compared treatment plans developed with 2 different Elekta multileaf collimators (MLC): Beam Modulator micro-MLC (mMLC) (4-mm leaf width at the isocenter) and standard MLC (10-mm leaf width at the isocenter). The comparison was performed for 15 patients with localized prostate cancer in 3DCRT and IMRT delivery; a total of 60 treatment plans were processed. The dose-volume histograms were used to provide the quantitative comparison between plans. In particular, we analyzed differences between rectum and bladder sparing in terms of a set of appropriate Vx (percentage of organ at risk [OAR] volume receiving the x dose) and differences between target conformity and coverage in terms of coverage factor and conformation number. Our analysis demonstrates that in 3DCRT there is an advantage in the use of Elekta Beam Modulator mMLC in terms of organ sparing; in particular, a significant decrease in rectal V60 and V50 (p = 0.001) and in bladder V70 and V65 (p = 0.007 and 0.002, respectively) was found. Moreover, a better target dose conformity was obtained (p = 0.002). IMRT plans comparison demonstrated no significant differences between the use of the 4 or 10-mm MLCs. Our analysis shows that in 3DCRT the use of the Elekta Beam Modulator mMLC gives a gain in target conformity and in OARs dose sparing whereas in IMRT plans there is no advantage.
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Affiliation(s)
- Alessandra Carosi
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy.
| | - Gianluca Ingrosso
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
| | - Elisabetta Ponti
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
| | - Barbara Tolu
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
| | - Alessandra Murgia
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
| | - Daniela di Cristino
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
| | - Riccardo Santoni
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata University General Hospital, Rome, Italy
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Simon TA, Kahler D, Simon WE, Fox C, Li J, Palta J, Liu C. An MLC calibration method using a detector array. Med Phys 2010; 36:4495-503. [PMID: 19928080 DOI: 10.1118/1.3218767] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The authors have developed a quantitative calibration method for a multileaf collimator (MLC) which measures individual leaf positions relative to the MLC backup jaw on an Elekta Synergy linear accelerator. METHODS The method utilizes a commercially available two-axis detector array (Profiler 2; Sun Nuclear Corporation, Melbourne, FL). To calibrate the MLC bank, its backup jaw is positioned at the central axis and the opposing jaw is retracted to create a half-beam configuration. The position of the backup jaws field edge is then measured with the array to obtain what is termed the radiation defined reference line. The positions of the individual leaf ends relative to this reference line are then inferred by the detector response in the leaf end penumbra. Iteratively adjusting and remeasuring the leaf end positions to within specifications completes the calibration. Using the backup jaw as a reference for the leaf end positions is based on three assumptions: (1) The leading edge of an MLC leaf bank is parallel to its backup jaw's leading edge, (2) the backup jaw position is reproducible, and (3) the measured radiation field edge created by each leaf end is representative of that leaf's position. Data from an electronic portal imaging device (EPID) were used in a similar analysis to check the results obtained with the array. RESULTS The relative leaf end positions measured with the array differed from those measured with the EPID by an average of 0.11+/-0.09 mm per leaf. The maximum leaf positional change measured with the Profiler 2 over a 3 month period was 0.51 mm. A leaf positional accuracy of +/-0.4 mm is easily attainable through the iterative calibration process. The method requires an average of 40 min to measure both leaf banks. CONCLUSIONS This work demonstrates that the Profiler 2 is an effective tool for efficient and quantitative MLC quality assurance and calibration.
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Affiliation(s)
- Thomas A Simon
- Department of Nuclear and Radiological Engineering, University of Florida, 202 Nuclear Science Building, Gainesville, Florida 32611-8300, USA.
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