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Three-dimensional IMRT QA of Monte Carlo and full scatter convolution algorithms based on 3D film dosimetry. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Mizuno H, Yamashita W, Okuyama H, Takase N, Tohyama N, Shimizu H, Fujita Y, Kito S, Nakaji T, Fukuda S. Dose response of a radiophotoluminescent glass dosimeter for TomoTherapy, CyberKnife, and flattening-filter-free linear accelerator output measurements in dosimetry audit. Phys Med 2021; 88:91-97. [PMID: 34214838 DOI: 10.1016/j.ejmp.2021.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/11/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE We experimentally determined the radiophotoluminescent glass dosimeter (RPLD) dose responses for TomoTherapy, CyberKnife, and flattening-filter-free (FFF) linear accelerator (linac) outputs for dosimetry audits in Japan. METHODS A custom-made solid phantom with a narrow central-axis spacing of three RPLD elements was used for output measurement to minimise the dose-gradient effect of the non-flattening filter beams. For RPLD dose estimation, we used the ISO 22127 formalism. Additional unit-specific correction factors were introduced and determined via the measured data. For TomoTherapy (7 units) and CyberKnife (4 units), the doses were measured under machine-specific reference fields. For FFF linac (5 units), in addition to the reference condition, we obtained the field-size effects for the range from 5×5 cm to 25×25 cm. RESULTS The correction factors were estimated as 1.008 and 0.999 for TomoTherapy and CyberKnife, respectively. For FFF linac, they ranged from 1.011 to 0.988 for 6 MV and from 1.011 to 0.997 for 10 MV as a function of the side length of the square field from 5 to 25 cm. The estimated uncertainties of the absorbed dose to water measured by RPLD for the units were 1.32%, 1.35%, and 1.30% for TomoTherapy, CyberKnife, and FFF linac, respectively. A summary of the dosimetry audits of these treatment units using the obtained correction factors is also presented. The average percentage differences between the measured and hospital-stated doses were <1% under all conditions. CONCLUSION RPLD can be successfully used as a dosimetry audit tool for modern treatment units.
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Affiliation(s)
- Hideyuki Mizuno
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan.
| | | | | | | | - Naoki Tohyama
- Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, Japan
| | | | | | - Satoshi Kito
- Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Japan; Graduate School of Medicine, Kyoto University, Japan
| | - Taku Nakaji
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
| | - Shigekazu Fukuda
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
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Axford A, Dikaios N, Roberts DA, Clark CH, Evans PM. An end-to-end assessment on the accuracy of adaptive radiotherapy in an MR-linac. Phys Med Biol 2021; 66:055021. [PMID: 33503604 DOI: 10.1088/1361-6560/abe053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop and demonstrate an end-to-end assessment procedure for adaptive radiotherapy (ART) within an MR-guided system. METHODS AND MATERIALS A 3D printed pelvic phantom was designed and constructed for use in this study. The phantom was put through the complete radiotherapy treatment chain, with planned internal changes made to model prostate translations and shape changes, allowing an investigation into three ART techniques commonly used. Absolute dosimetry measurements were made within the phantom using both gafchromic film and alanine. Comparisons between treatment planning system (TPS) calculations and measured dose values were made using the gamma evaluation with criteria of 3 mm/3% and 2 mm/2%. RESULTS Gamma analysis evaluations for each type of treatment plan adaptation investigated showed a very high agreement with pass rates for each experiment ranging from 98.10% to 99.70% and 92.60% to 97.55%, for criteria of 3%/3 mm and 2%/2 mm respectively. These pass rates were consistent for both shape and position changes. Alanine measurements further supported the results, showing an average difference of 1.98% from the TPS. CONCLUSION The end-to-end assessment procedure provided demanding challenges for treatment plan adaptations to demonstrate the capabilities and achieved high consistency in all findings.
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Affiliation(s)
- A Axford
- The Centre for Vision Speech and Signal Processing (CVSSP), University of Surrey, Guildford, Surrey, United Kingdom. Metrology for Medical Physics (MEMPHYS), National Physical Laboratory, Teddington, United Kingdom
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Bouchard H. Reference dosimetry of modulated and dynamic photon beams. Phys Med Biol 2021; 65:24TR05. [PMID: 33438582 DOI: 10.1088/1361-6560/abc3fb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the late 1980s, a new technique was proposed that would revolutionize radiotherapy. Now referred to as intensity-modulated radiotherapy, it is at the core of state-of-the-art photon beam delivery techniques, such as helical tomotherapy and volumetric modulated arc therapy. Despite over two decades of clinical application, there are still no established guidelines on the calibration of dynamic modulated photon beams. In 2008, the IAEA-AAPM work group on nonstandard photon beam dosimetry published a formalism to support the development of a new generation of protocols applicable to nonstandard beam reference dosimetry (Alfonso et al 2008 Med. Phys. 35 5179-86). The recent IAEA Code of Practice TRS-483 was published as a result of this initiative and addresses exclusively small static beams. But the plan-class specific reference calibration route proposed by Alfonso et al (2008 Med. Phys. 35 5179-86) is a change of paradigm that is yet to be implemented in radiotherapy clinics. The main goals of this paper are to provide a literature review on the dosimetry of nonstandard photon beams, including dynamic deliveries, and to discuss anticipated benefits and challenges in a future implementation of the IAEA-AAPM formalism on dynamic photon beams.
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Affiliation(s)
- Hugo Bouchard
- Département de physique, Université de Montréal, Complexe des sciences, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada. Centre de recherche du Centre hospitalier de l'Université de Montréal, 900 Rue Saint-Denis, Montréal, Québec H2X 0A9, Canada. Département de radio-oncologie, Centre hospitalier de l'Université de Montréal (CHUM), 1051 Rue Sanguinet, Montréal, Québec H2X 3E4, Canada
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Wesolowska P, Georg D, Lechner W, Kazantsev P, Bokulic T, Tedgren AC, Adolfsson E, Campos AM, Alves VGL, Suming L, Hao W, Ekendahl D, Koniarova I, Bulski W, Chelminski K, Samper JLA, Vinatha SP, Rakshit S, Siri S, Tomsejm M, Tenhunen M, Povall J, Kry SF, Followill DS, Thwaites DI, Izewska J. Testing the methodology for a dosimetric end-to-end audit of IMRT/VMAT: results of IAEA multicentre and national studies. Acta Oncol 2019; 58:1731-1739. [PMID: 31423867 DOI: 10.1080/0284186x.2019.1648859] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: Within an International Atomic Energy Agency (IAEA) co-ordinated research project (CRP), a remote end-to-end dosimetric quality audit for intensity modulated radiation therapy (IMRT)/ volumetric arc therapy (VMAT) was developed to verify the radiotherapy chain including imaging, treatment planning and dose delivery. The methodology as well as the results obtained in a multicentre pilot study and national trial runs conducted in close cooperation with dosimetry audit networks (DANs) of IAEA Member States are presented.Material and methods: A solid polystyrene phantom containing a dosimetry insert with an irregular solid water planning target volume (PTV) and organ at risk (OAR) was designed for this audit. The insert can be preloaded with radiochromic film and four thermoluminescent dosimeters (TLDs). For the audit, radiotherapy centres were asked to scan the phantom, contour the structures, create an IMRT/VMAT treatment plan and irradiate the phantom. The dose prescription was to deliver 4 Gy to the PTV in two fractions and to limit the OAR dose to a maximum of 2.8 Gy. The TLD measured doses and film measured dose distributions were compared with the TPS calculations.Results: Sixteen hospitals from 13 countries and 64 hospitals from 6 countries participated in the multicenter pilot study and in the national runs, respectively. The TLD results for the PTV were all within ±5% acceptance limit for the multicentre pilot study, whereas for national runs, 17 participants failed to meet this criterion. All measured doses in the OAR were below the treatment planning constraint. The film analysis identified seven plans in national runs below the 90% passing rate gamma criteria.Conclusion: The results proved that the methodology of the IMRT/VMAT dosimetric end-to-end audit was feasible for its intended purpose, i.e., the phantom design and materials were suitable; the phantom was easy to use and it was robust enough for shipment. Most importantly the audit methodology was capable of identifying suboptimal IMRT/VMAT delivery.
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Affiliation(s)
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Vienna, Austria
| | - Wolfgang Lechner
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Vienna, Austria
| | | | | | - Asa Carlsson Tedgren
- Medical Radiation Physics, Department of Medical Physics and Department of Medical and Health Sciences, Linkoping University, Linköping, Sweden
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Emelie Adolfsson
- Medical Radiation Physics, Department of Medical Physics and Department of Medical and Health Sciences, Linkoping University, Linköping, Sweden
| | | | | | - Luo Suming
- Chinese Centre for Disease Control and Prevention, Beijing, China
| | - Wu Hao
- Beijing Cancer Hospital, Beijing, China
| | | | - Irena Koniarova
- National Radiation Protection Institute, Prague, Czech Republic
| | - Wojciech Bulski
- Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland
| | - Krzysztof Chelminski
- Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw, Poland
| | | | - Sumanth Panyam Vinatha
- Radiation Standards Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre Trombay, Mumbai, India
| | - Sougata Rakshit
- Radiation Standards Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre Trombay, Mumbai, India
| | - Srimanoroth Siri
- SSDL, Bureau of Radiation and Medical Devices, Department of Medical Science, Nonthaburi, Thailand
| | - Milan Tomsejm
- CHU Charleroi, Hopital Andre Vesale, Montigny-le-Tilleul, Belgium
| | - Mikko Tenhunen
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Julie Povall
- University of Leeds, St James’s University Hospital, Leeds, United Kingdom
| | - Stephen F. Kry
- Imaging and Radiation Oncology Core Houston QA Centre, Anderson Cancer Centre, Houston, TX, USA
| | - David S. Followill
- Imaging and Radiation Oncology Core Houston QA Centre, Anderson Cancer Centre, Houston, TX, USA
| | - David I. Thwaites
- University of Leeds, St James’s University Hospital, Leeds, United Kingdom
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, Australia
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Chiavassa S, Bessieres I, Edouard M, Mathot M, Moignier A. Complexity metrics for IMRT and VMAT plans: a review of current literature and applications. Br J Radiol 2019; 92:20190270. [PMID: 31295002 PMCID: PMC6774599 DOI: 10.1259/bjr.20190270] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 12/21/2022] Open
Abstract
Modulated radiotherapy with multileaf collimators is widely used to improve target conformity and normal tissue sparing. This introduced an additional degree of complexity, studied by multiple teams through different properties. Three categories of complexity metrics were considered in this review: fluence, deliverability and accuracy metrics. The first part of this review is dedicated to the inventory of these complexity metrics. Different applications of these metrics emerged. Influencing the optimizer by integrating complexity metrics into the cost function has been little explored and requires more investigations. In modern treatment planning system, it remains confined to MUs or treatment time limitation. A large majority of studies calculated metrics only for analysis, without plan modification. The main application was to streamline the patient specific quality assurance workload, investigating the capability of complexity metrics to predict patient specific quality assurance results. Additionally complexity metrics were used to analyze behaviour of TPS optimizer, compare TPS, operators and plan properties, and perform multicentre audit. Their potential was also explored in the context of adaptive radiotherapy and automation planning. The second part of the review gives an overview of these studies based on the complexity metrics.
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Affiliation(s)
- Sophie Chiavassa
- Department of Medical Physics, Institut de Cancérologie de l’Ouest Centre René Gauducheau, 44805 Saint-Herblain, France
| | - Igor Bessieres
- Departement of Medical Physics, Centre Georges-François Leclerc, 1 rue Professeur Marion, 21000 Dijon, France
| | - Magali Edouard
- Department of Radiation Oncology, Gustave Roussy, 114 rue Édouard-Vaillant, 94805 Villejuif, France
| | - Michel Mathot
- Liege University Hospital, Domaine du Sart Tilman - B.35 - B-4000 LIEGE1, Belgium
| | - Alexandra Moignier
- Department of Medical Physics, Institut de Cancérologie de l’Ouest Centre René Gauducheau, 44805 Saint-Herblain, France
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Bradley FL. Radiotherapy dosimetry audits carried out in Ireland at the request of the National Radiation Safety Committee in 2014 & 2017. Phys Med 2019; 65:94-98. [DOI: 10.1016/j.ejmp.2019.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/25/2019] [Accepted: 08/01/2019] [Indexed: 10/26/2022] Open
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Abstract
PURPOSE The IAEA newly developed "end-to-end" audit methodology for on-site verification of IMRT dose delivery has been carried out in Portugal in 2018. The main goal was to evaluate the physical aspects of the head and neck (H&N) cancer IMRT treatments. This paper presents the national results. METHODS All institutions performing IMRT treatments in Portugal, 20 out of 24, have voluntarily participated in this audit. Following the adopted methodology, a Shoulder, Head and Neck End-to-End phantom (SHANE) - that mimics an H&N region, underwent all steps of an IMRT treatment, according to the local practices. The measurements using an ionization chamber placed inside the SHANE phantom at four reference locations (three in PTVs and one in the spinal cord) and an EBT3 film positioned in a coronal plane were compared with calculated doses. FilmQA Pro software was used for film analysis. RESULTS For ionization chamber measurements, the percent difference was within the specified tolerances of ±5% for PTVs and ±7% for the spinal cord in all participating institutions. Considering film analysis, gamma passing rates were on average 96.9%±2.9% for a criterion of 3%/3 mm, 20% threshold, all above the acceptance limit of 90%. CONCLUSIONS The national results of the H&N IMRT audit showed a compliance between the planned and the delivered doses within the specified tolerances, confirming no major reasons for concern. At the same time the audit identified factors that contributed to increased uncertainties in the IMRT dose delivery in some institutions resulting in recommendations for quality improvement.
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Kumar L, Yadav G, Kishore V, Bhushan M, Gairola M, Tripathi D. Validation of the RapidArc Delivery System Using a Volumetric Phantom as Per Task Group Report 119 of the American Association of Physicists in Medicine. J Med Phys 2019; 44:126-134. [PMID: 31359931 PMCID: PMC6580814 DOI: 10.4103/jmp.jmp_118_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Aim This study validated the RapidArc (RA) delivery using a volumetric ArcCHECK phantom as per the guidelines proposed in Task Group Report 119 from the American Association of Physicists in Medicine Task group 119 (AAPM TG 119). This study also investigated the impact of the Acuros XB (AXB) algorithm in comparison to analytical anisotropic algorithm (AAA) on the RA dose calculations in the homogeneous medium of the ArcCHECK phantom. Materials and Methods A volumetric ArcCHECK phantom along with AAPM TG 119 tests was used to evaluate the RA plans and verify the dose delivery for photon beam of 6 MV energy. Results The RA planning results were comparable and satisfied the planning criteria stated in the TG 119 report for all test cases. The average percentage gamma passing rates for the AAA-calculated plans were 98.5 (standard deviation [SD]: 0.6), 98.5 (SD: 1.3), and 98.1 (SD: 2.0) and for the AXB-calculated plans were 95.1 (SD: 1.8), 96.1 (SD: 1.3), and 94.0 (SD: 0.9) for the Clinac-iX (6 MV) and TrueBeam (TB)-STx (6 MV_filtered beam [FB] and 6 MV_flattening filter-free beam [FFFB]), respectively. For ion chamber measurements, the average percentage dose differences for the AAA-calculated plans were 1.5 (SD: 2.5), 2.7 (SD: 1.4), and 1.4(SD: 2.7) and for AXB-calculated plans were 2.3 (SD: 1.6), 3.2 (SD: 1.5), and 2.3 (SD: 2.0) for Clinac-iX (6 MV) and TB-STx (6 MV_FB and 6 MV_FFFB), respectively. Conclusion Thus, the ArcCHECK can successfully be utilized for the validation of the RA delivery. The AXB has potential to perform dose calculations comparable to those of the AAA for RA plans in the homogeneous medium of the ArcCHECK phantom.
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Affiliation(s)
- Lalit Kumar
- Department of Radiation Oncology, Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India.,Department of Applied Science and Humanities, Dr. A.P.J Abdul Kalam Technical University, Lucknow, Uttar Pradesh, India
| | - Girigesh Yadav
- Department of Radiation Oncology, Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Vimal Kishore
- Department of Applied Science and Humanities, Bundelkhand Institute of Engineering and Technology, Jhansi, Uttar Pradesh, India
| | - Manindra Bhushan
- Department of Radiation Oncology, Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India.,Department of Applied Science, Amity School of Applied Sciences, Amity University, Noida, Uttar Pradesh, India
| | - Munish Gairola
- Department of Radiation Oncology, Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Deepak Tripathi
- Department of Applied Science, Amity School of Applied Sciences, Amity University, Noida, Uttar Pradesh, India
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Antoine M, Ralite F, Soustiel C, Marsac T, Sargos P, Cugny A, Caron J. Use of metrics to quantify IMRT and VMAT treatment plan complexity: A systematic review and perspectives. Phys Med 2019; 64:98-108. [PMID: 31515041 DOI: 10.1016/j.ejmp.2019.05.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Fixed-field intensity modulated radiation therapy (FF-IMRT) or volumetric modulated arc therapy (VMAT) beams complexity is due to fluence fluctuation. Pre-treatment Quality Assurance (PTQA) failure could be linked to it. Several plan complexity metrics (PCM) have been published to quantify this complexity but in a heterogeneous formalism. This review proposes to gather different PCM and to discuss their eventual PTQA failure identifier abilities. METHODS AND MATERIALS A systematic literature search and outcome extraction from MEDLINE/PubMed (National Center for Biotechnology Information, NCBI) was performed. First, a list and a synthesis of available PCM is made in a homogeneous formalism. Second, main results relying on the link between PCM and PTQA results but also on other uses are listed. RESULTS A total of 163 studies were identified and n = 19 were selected after inclusion and exclusion criteria application. Difference is made between fluence and degree of freedom (DOF)-based PCM. Results about the PCM potential as PTQA failure identifier are described and synthesized. Others uses are also found in quality, big data, machine learning and audit procedure. CONCLUSIONS A state of the art is made thanks to this homogeneous PCM classification. For now, PCM should be seen as a planning procedure quality indicator although PTQA failure identifier results are mitigated. However limited clinical use seems possible for some cases. Yet, addressing the general PTQA failure prediction case could be possible with the big data or machine learning help.
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Affiliation(s)
- Mikaël Antoine
- Service d'onco-radiothérapie, Polyclinique de Bordeaux Nord, 33000 Bordeaux, France; Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France.
| | - Flavien Ralite
- Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France; SUBATECH, IMT-Atlantique, CNRS/IN2P3, Université de Nantes, Nantes, France
| | - Charles Soustiel
- Department of Radiotherapy, Centre Hospitalier de Dax, Dax, France
| | - Thomas Marsac
- Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France
| | - Paul Sargos
- Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France
| | - Audrey Cugny
- Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France
| | - Jérôme Caron
- Department of Radiotherapy, Institut Bergonié, Comprehensive Cancer Centre, F-33000 Bordeaux, France
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Smyth G, Evans PM, Bamber JC, Mandeville HC, Rollo Moore A, Welsh LC, Saran FH, Bedford JL. Dosimetric accuracy of dynamic couch rotation during volumetric modulated arc therapy (DCR-VMAT) for primary brain tumours. Phys Med Biol 2019; 64:08NT01. [PMID: 30808011 PMCID: PMC6877349 DOI: 10.1088/1361-6560/ab0a8e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Radiotherapy treatment plans using dynamic couch rotation during volumetric modulated arc therapy (DCR-VMAT) reduce the dose to organs at risk (OARs) compared to coplanar VMAT, while maintaining the dose to the planning target volume (PTV). This paper seeks to validate this finding with measurements. DCR-VMAT treatment plans were produced for five patients with primary brain tumours and delivered using a commercial linear accelerator (linac). Dosimetric accuracy was assessed using point dose and radiochromic film measurements. Linac-recorded mechanical errors were assessed by extracting deviations from log files for multi-leaf collimator (MLC), couch, and gantry positions every 20 ms. Dose distributions, reconstructed from every fifth log file sample, were calculated and used to determine deviations from the treatment plans. Median (range) treatment delivery times were 125 s (123-133 s) for DCR-VMAT, compared to 78 s (64-130 s) for coplanar VMAT. Absolute point doses were 0.8% (0.6%-1.7%) higher than prediction. For coronal and sagittal films, respectively, 99.2% (96.7%-100%) and 98.1% (92.9%-99.0%) of pixels above a 20% low dose threshold reported gamma <1 for 3% and 3 mm criteria. Log file analysis showed similar gantry rotation root-mean-square error (RMSE) for VMAT and DCR-VMAT. Couch rotation RMSE for DCR-VMAT was 0.091° (0.086-0.102°). For delivered dose reconstructions, 100% of pixels above a 5% low dose threshold reported gamma <1 for 2% and 2 mm criteria in all cases. DCR-VMAT, for the primary brain tumour cases studied, can be delivered accurately using a commercial linac.
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Affiliation(s)
- Gregory Smyth
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom. Author to whom any correspondence should be addressed
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Miri N, Vial P, Greer PB. Remote dosimetric auditing of clinical trials: The need for vendor specific models to convert images to dose. J Appl Clin Med Phys 2019; 20:175-183. [PMID: 30597730 PMCID: PMC6333142 DOI: 10.1002/acm2.12521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 10/02/2018] [Accepted: 11/04/2018] [Indexed: 11/09/2022] Open
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 using images from an electronic portal imaging device (EPID) on a Varian linear accelerator. It was tuned using beam profiles and field size factors (FSFs) of a series of square fields measured in water tank. This work investigates the need for vendor specific conversion models for image-based auditing. The EPID measured profile and FSF data for Varian (vendor 1) and Elekta (vendor 2) systems are compared along with the performance of the existing Varian model (VM) and a new Elekta model (EM) for a series of audit IMRT fields measured on vendor 2 systems. MATERIALS AND METHODS The EPID measured beam profile and FSF data were studied for the two vendors to quantify and understand their relevant dosimetric differences. Then, an EM was developed converting EPID to dose in the virtual water phantom using a vendor 2 water tank data and images from corresponding EPID. The VM and EM were compared for predicting vendor 2 measured dose in water tank. Then, the performance of the new EM was compared to the VM for auditing of 54 IMRT fields from four vendor 2 facilities. Statistical significance of using vendor specific models was determined. RESULTS Observed dosimetry differences between the two vendors suggested developing an EM would be beneficial. The EM performed better than VM for vendor 2 square and IMRT fields. The IMRT audit gamma pass rates were (99.8 ± 0.5)%, (98.6 ± 2.3)% and (97.0 ± 3.0)% at respectively 3%/3 mm, 3%/2 mm and 2%/2 mm with improvements at most fields compared with using the VM. For the pilot audit, the difference between gamma results of the two vendors was reduced when using vendor specific models (VM: P < 0.0001, vendor specific models: P = 0.0025). CONCLUSION A new model was derived to convert images from vendor 2 EPIDs to dose for remote auditing vendor 2 deliveries. Using vendor specific models is recommended to remotely audit systems from different vendors, however, the improvements found were not major.
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Affiliation(s)
- Narges Miri
- School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Philip Vial
- Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia.,Ingham Institute of Applied Medical Research, Sydney, Australia.,Institute of Medical Physics, School of Physics, University of Sydney, Sydney, Australia.,South Western Sydney Clinical School, University of New South Wales, Sydney, Australia
| | - Peter B Greer
- School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, NSW, Australia.,Calvary Mater Newcastle Hospital, Newcastle, New South Wales, Australia
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Tuntipumiamorn L, Tangboonduangjit P, Sanghangthum T, Rangseevijitprapa R, Khamfongkhruea C, Niyomthai T, Vuttiprasertpong B, Supanant S, Chatchaipaiboon N, Iampongpaiboon P, Nakkrasae P, Jaikuna T. Multi-institutional evaluation using the end-to-end test for implementation of dynamic techniques of radiation therapy in Thailand. Rep Pract Oncol Radiother 2019; 24:124-132. [PMID: 30532660 PMCID: PMC6265520 DOI: 10.1016/j.rpor.2018.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/23/2018] [Accepted: 11/10/2018] [Indexed: 10/27/2022] Open
Abstract
AIM In this study, an accuracy survey of intensity-modulated radiation therapy (IMRT) and volumetric arc radiation therapy (VMAT) implementation in radiotherapy centers in Thailand was conducted. BACKGROUND It is well recognized that there is a need for radiotherapy centers to evaluate the accuracy levels of their current practices, and use the related information to identify opportunities for future development. MATERIALS AND METHODS An end-to-end test using a CIRS thorax phantom was carried out at 8 participating centers. Based on each center's protocol for simulation and planning, linac-based IMRT or VMAT plans were generated following the IAEA (CRP E24017) guidelines. Point doses in the region of PTVs and OARs were obtained from 5 ionization chamber readings and the dose distribution from the radiochromic films. The global gamma indices of the measurement doses and the treatment planning system calculation doses were compared. RESULTS The large majority of the RT centers (6/8) fulfilled the dosimetric goals, with the measured and calculated doses at the specification points agreeing within ±3% for PTV and ±5% for OARS. At 2 centers, TPS underestimated the lung doses by about 6% and spinal cord doses by 8%. The mean percentage gamma pass rates for the 8 centers were 98.29 ± 0.67% (for the 3%/3 mm criterion) and 96.72 ± 0.84% (for the 2%/2 mm criterion). CONCLUSIONS The 8 participating RT centers achieved a satisfactory quality level of IMRT/VMAT clinical implementation.
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Affiliation(s)
- Lalida Tuntipumiamorn
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Puangpen Tangboonduangjit
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Taweap Sanghangthum
- Division of Radiation Oncology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Rattapol Rangseevijitprapa
- Division of Radiation Oncology, Faculty of Medicine, Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand
| | | | | | | | | | | | - Porntip Iampongpaiboon
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pitchayut Nakkrasae
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Tanwiwat Jaikuna
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Miri N, Legge K, Colyvas K, Lehmann J, Vial P, Moore A, Harris M, Greer PB. A remote EPID-based dosimetric TPS-planned audit of centers for clinical trials: outcomes and analysis of contributing factors. Radiat Oncol 2018; 13:178. [PMID: 30223857 PMCID: PMC6142693 DOI: 10.1186/s13014-018-1125-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/03/2018] [Indexed: 12/17/2022] Open
Abstract
Background A novel remote method for external dosimetric TPS-planned auditing of intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for clinical trials using electronic portal imaging device (EPID) has been developed. The audit has been applied to multiple centers across Australia and New Zealand. This work aims to assess the audit outcomes and explores the variables that contributed to the audit results. Methods Thirty audits were performed of 21 radiotherapy facilities, 17 facilities underwent IMRT audits and 13 underwent VMAT audits. The assessment was based on comparisons between the delivered doses derived from images acquired with EPIDs and planned doses from the local treatment planning systems (TPS). Gamma pass-rate (GPR) and gamma mean value (GMV) were calculated for each IMRT field and VMAT arc (total 268 comparisons). A multiple variable linear model was applied to the GMV results (3%/3 mm criteria) to assess the influence and significance of explanatory variables. The explanatory variables were Linac-TPS combination, TPS grid resolution, IMRT/VMAT delivery, age of EPID, treatment site, record and verification system (R&V) type and dose-rate. Finally, the audit results were compared with other recent audits by calculating the incidence ratio (IR) as a ratio of the observed mean/median GPRs for the remote audit to the other audits. Results The average (± 1 SD) of the centers’ GPRs were: 99.3 ± 1.9%, 98.6 ± 2.7% & 96.2 ± 5.5% at 3%, 3 mm, 3%, 2 mm and 2%, 2 mm criteria respectively. The most determinative variables on the GMVs were Linac-TPS combination, TPS grid resolution and IMRT/VMAT delivery type. The IR values were 1 for seven comparisons, indicating similar GPRs of the remote audit with the reference audits and > 1 for four comparisons, indicating higher GPRs of the remote audit than the reference audits. Conclusion The remote dosimetry audit method for clinical trials demonstrated high GPRs and provided results comparable to established more resource-intensive audit methods. Several factors were found to influence the results including some effect of Linac-TPS combination. Electronic supplementary material The online version of this article (10.1186/s13014-018-1125-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Narges Miri
- University of Newcastle, Newcastle, NSW, Australia
| | | | - Kim Colyvas
- University of Newcastle, Newcastle, NSW, Australia
| | - Joerg Lehmann
- University of Newcastle, Newcastle, NSW, Australia.,Calvary Mater Newcastle, Newcastle, NSW, Australia
| | - Philip Vial
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Liverpool, NSW, Australia.,University of Sydney, Sydney, NSW, Australia
| | | | | | - Peter B Greer
- University of Newcastle, Newcastle, NSW, Australia. .,Calvary Mater Newcastle, Newcastle, NSW, Australia.
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Kumazaki Y, Ozawa S, Nakamura M, Kito S, Minemura T, Tachibana H, Nishio T, Ishikura S, Nishimura Y. An end-to-end postal audit test to examine the coincidence between the imaging isocenter and treatment beam isocenter of the IGRT linac system for Japan Clinical Oncology Group (JCOG) clinical trials. Phys Med 2018; 53:145-152. [PMID: 30241749 DOI: 10.1016/j.ejmp.2018.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/06/2018] [Accepted: 08/12/2018] [Indexed: 10/28/2022] Open
Abstract
PURPOSE The aim of this study was to develop an end-to-end postal audit test to examine the coincidence between the imaging isocenter and treatment beam isocenter of the image guided radiotherapy (IGRT) linac system for Japan Clinical Oncology Group (JCOG) trials, as a part of IGRT credentialing of institutions participating in JCOG trials. METHODS We developed an end-to-end postal audit test to verify radiation positional errors associated with IGRT techniques. This test is intended for simulating a clinical IGRT flow and uses a static cubic phantom measuring 15 × 15 × 15 cm3 and weighing approximately 3.4 kg. The phantom has four gold fiducial markers and a spherical dummy target for setup, with known shift values from the phantom center. Two pairs of Gafchromic RTQA2 films were inserted 5 mm from the phantom's anterior-posterior and right-left surfaces. Radiation positional errors at the isocenter were determined by analyzing the center of the radiation field on the films and the known shift values of the dummy target. The test was performed on 47 IGRT devices at 35 institutions. RESULTS Radiation positional errors were within acceptance levels (1 mm/1°) for 42 IGRT devices (89.4%) in the first check. Median time to complete IGRT credentialing was 11.5 days. This audit method was applicable for any radiotherapy machine with an IGRT device. CONCLUSIONS A postal audit test to verify radiation positional errors for JCOG trials was successfully developed. In the postal audit, all but one institution passed this credentialing item within two trials.
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Affiliation(s)
- Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan.
| | - Shuichi Ozawa
- Department of Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Satoshi Kito
- Radiation Physics Section, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-Ku, Tokyo 113-8677, Japan
| | - Toshiyuki Minemura
- Center for Cancer Control and Information Services, National Cancer Center, 5-1-1 Tsukiji, Chuo-Ku, Tokyo 104-0045, Japan
| | - Hidenobu Tachibana
- Particle Therapy Division, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa City, Chiba 277-8577, Japan
| | - Teiji Nishio
- Department of Medical Physics, Tokyo Women's Medical University, 8-1 Kawatamachi, Shinjuku, Tokyo 162-8666, Japan
| | - Satoshi Ishikura
- Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan
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Pogson E, Arumugam S, Hansen C, Currie M, Blake S, Roberts N, Carolan M, Vial P, Alharthi T, Holloway L, Thwaites D. Comparison of multi-institutional pre-treatment verification for VMAT of nasopharynx with delivery errors. Phys Med 2018; 53:25-31. [DOI: 10.1016/j.ejmp.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/19/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022] Open
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A virtual dosimetry audit - Towards transferability of gamma index analysis between clinical trial QA groups. Radiother Oncol 2018; 125:398-404. [PMID: 29100698 DOI: 10.1016/j.radonc.2017.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 11/22/2022]
Abstract
PURPOSE Quality assurance (QA) for clinical trials is important. Lack of compliance can affect trial outcome. Clinical trial QA groups have different methods of dose distribution verification and analysis, all with the ultimate aim of ensuring trial compliance. The aim of this study was to gain a better understanding of different processes to inform future dosimetry audit reciprocity. MATERIALS Six clinical trial QA groups participated. Intensity modulated treatment plans were generated for three different cases. A range of 17 virtual 'measurements' were generated by introducing a variety of simulated perturbations (such as MLC position deviations, dose differences, gantry rotation errors, Gaussian noise) to three different treatment plan cases. Participants were blinded to the 'measured' data details. Each group analysed the datasets using their own gamma index (γ) technique and using standardised parameters for passing criteria, lower dose threshold, γ normalisation and global γ. RESULTS For the same virtual 'measured' datasets, different results were observed using local techniques. For the standardised γ, differences in the percentage of points passing with γ < 1 were also found, however these differences were less pronounced than for each clinical trial QA group's analysis. These variations may be due to different software implementations of γ. CONCLUSIONS This virtual dosimetry audit has been an informative step in understanding differences in the verification of measured dose distributions between different clinical trial QA groups. This work lays the foundations for audit reciprocity between groups, particularly with more clinical trials being open to international recruitment.
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Lehmann J, Alves A, Dunn L, Shaw M, Kenny J, Keehan S, Supple J, Gibbons F, Manktelow S, Oliver C, Kron T, Williams I, Lye J. Dosimetric end-to-end tests in a national audit of 3D conformal radiotherapy. Phys Imaging Radiat Oncol 2018; 6:5-11. [PMID: 33458381 PMCID: PMC7807562 DOI: 10.1016/j.phro.2018.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 03/14/2018] [Accepted: 03/14/2018] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Independent dosimetry audits improve quality and safety of radiation therapy. This work reports on design and findings of a comprehensive 3D conformal radiotherapy (3D-CRT) Level III audit. MATERIALS AND METHODS The audit was conducted as onsite audit using an anthropomorphic thorax phantom in an end-to-end test by the Australian Clinical Dosimetry Service (ACDS). Absolute dose point measurements were performed with Farmer-type ionization chambers. The audited treatment plans included open and half blocked fields, wedges and lung inhomogeneities. Audit results were determined as Pass Optimal Level (deviations within 3.3%), Pass Action Level (greater than 3.3% but within 5%) and Out of Tolerance (beyond 5%), as well as Reported Not Scored (RNS). The audit has been performed between July 2012 and January 2018 on 94 occasions, covering approximately 90% of all Australian facilities. RESULTS The audit pass rate was 87% (53% optimal). Fifty recommendations were given, mainly related to planning system commissioning. Dose overestimation behind low density inhomogeneities by the analytical anisotropic algorithm (AAA) was identified across facilities and found to extend to beam setups which resemble a typical breast cancer treatment beam placement. RNS measurements inside lung showed a variation in the opposite direction: AAA under-dosed a target beyond lung and over-dosed the lung upstream and downstream of the target. Results also highlighted shortcomings of some superposition and convolution algorithms in modelling large angle wedges. CONCLUSIONS This audit showed that 3D-CRT dosimetry audits remain relevant and can identify fundamental global and local problems that also affect advanced treatments.
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Affiliation(s)
- Joerg Lehmann
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
- Institute of Medical Physics, School of Physics A28, University of Sydney NSW 2006, Australia
- School of Mathematical and Physical Sciences, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, 124 La Trobe Street, Melbourne, VIC 3000, Australia
| | - Andrew Alves
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Leon Dunn
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Maddison Shaw
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, 124 La Trobe Street, Melbourne, VIC 3000, Australia
| | - John Kenny
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Stephanie Keehan
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, 124 La Trobe Street, Melbourne, VIC 3000, Australia
| | - Jeremy Supple
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Francis Gibbons
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Sophie Manktelow
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Chris Oliver
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Tomas Kron
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, 124 La Trobe Street, Melbourne, VIC 3000, Australia
- Department of Radiation Oncology, Peter MacCallum Cancer Center, 305 Grattan Street, Melbourne, VIC 3000, Australia
| | - Ivan Williams
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - Jessica Lye
- Australian Clinical Dosimetry Service (ACDS), Australian Radiation Protection and National Safety Agency (ARPANSA), 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
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Carlino A, Gouldstone C, Kragl G, Traneus E, Marrale M, Vatnitsky S, Stock M, Palmans H. End-to-end tests using alanine dosimetry in scanned proton beams. ACTA ACUST UNITED AC 2018; 63:055001. [DOI: 10.1088/1361-6560/aaac23] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Izewska J, Lechner W, Wesolowska P. Global availability of dosimetry audits in radiotherapy: The IAEA dosimetry audit networks database. Phys Imaging Radiat Oncol 2018; 5:1-4. [PMID: 33458360 PMCID: PMC7807735 DOI: 10.1016/j.phro.2017.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/12/2017] [Accepted: 12/18/2017] [Indexed: 10/26/2022] Open
Abstract
The International Atomic Energy Agency (IAEA) has established a database describing activities of dosimetry audit networks (DAN) in radiotherapy. Since 2010 the data on different aspects of the dosimetry audit have been collected. This information has allowed for the analysis and comparison of current practices in dosimetry auditing activities worldwide. Overall, 79 organizations in 58 countries confirmed that they offer dosimetry audit services for radiotherapy; however, access of radiotherapy centres to the audit remains insufficient. Increased availability of audits is necessary to improve dosimetry practices, reduce the likelihood of errors and the consequences that would result for patients' health.
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Affiliation(s)
- Joanna Izewska
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, A-1400 Vienna, Austria
| | | | - Paulina Wesolowska
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, A-1400 Vienna, Austria
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Seravalli E, Houweling AC, Van Battum L, Raaben TA, Kuik M, de Pooter JA, Van Gellekom MP, Kaas J, de Vries W, Loeff EA, Van de Kamer JB. Auditing local methods for quality assurance in radiotherapy using the same set of predefined treatment plans. Phys Imaging Radiat Oncol 2018; 5:19-25. [PMID: 33458364 PMCID: PMC7807668 DOI: 10.1016/j.phro.2018.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 01/13/2018] [Accepted: 01/15/2018] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND AND PURPOSE Local implementation of plan-specific quality assurance (QA) methods for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) treatment plans may vary because of dissimilarities in procedures, equipment and software. The purpose of this work is detecting possible differences between local QA findings and those of an audit, using the same set of treatment plans. METHODS A pre-defined set of clinical plans was devised and imported in the participating institute's treatment planning system for dose computation. The dose distribution was measured using an ionisation chamber, radiochromic film and an ionisation chamber array. The centres performed their own QA, which was compared to the audit findings. The agreement/disagreement between the audit and the institute QA results were assessed along with the differences between the dose distributions measured by the audit team and computed by the institute. RESULTS For the majority of the cases the results of the audit were in agreement with the institute QA findings: ionisation chamber: 92%, array: 88%, film: 76% of the total measurements. In only a few of these cases the evaluated measurements failed for both: ionisation chamber: 2%, array: 4%, film: 0% of the total measurements. CONCLUSION Using predefined treatment plans, we found that in approximately 80% of the evaluated measurements the results of local QA of IMRT and VMAT plans were in line with the findings of the audit. However, the percentage of agreement/disagreement depended on the characteristics of the measurement equipment used and on the analysis metric.
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Affiliation(s)
- Enrica Seravalli
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Antonetta C. Houweling
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Leo Van Battum
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Marc Kuik
- Department of Radiotherapy, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | | | | | - Jochem Kaas
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Wilfred de Vries
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Erik A. Loeff
- Department of Radiation Oncology, Erasmus MC-Cancer Institute, Rotterdam, The Netherlands
| | - Jeroen B. Van de Kamer
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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Pasler M, Hernandez V, Jornet N, Clark CH. Novel methodologies for dosimetry audits: Adapting to advanced radiotherapy techniques. Phys Imaging Radiat Oncol 2018; 5:76-84. [PMID: 33458373 PMCID: PMC7807589 DOI: 10.1016/j.phro.2018.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 03/08/2018] [Accepted: 03/08/2018] [Indexed: 11/25/2022] Open
Abstract
With new radiotherapy techniques, treatment delivery is becoming more complex and accordingly, these treatment techniques require dosimetry audits to test advanced aspects of the delivery to ensure best practice and safe patient treatment. This review of novel methodologies for dosimetry audits for advanced radiotherapy techniques includes recent developments and future techniques to be applied in dosimetry audits. Phantom-based methods (i.e. phantom-detector combinations) including independent audit equipment and local measurement equipment as well as phantom-less methods (i.e. portal dosimetry, transmission detectors and log files) are presented and discussed. Methodologies for both conventional linear accelerator (linacs) and new types of delivery units, i.e. Tomotherapy, stereotactic devices and MR-linacs, are reviewed. Novel dosimetry audit techniques such as portal dosimetry or log file evaluation have the potential to allow parallel auditing (i.e. performing an audit at multiple institutions at the same time), automation of data analysis and evaluation of multiple steps of the radiotherapy treatment chain. These methods could also significantly reduce the time needed for audit and increase the information gained. However, to maximise the potential, further development and harmonisation of dosimetry audit techniques are required before these novel methodologies can be applied.
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Affiliation(s)
- Marlies Pasler
- Lake Constance Radiation Oncology Center Singen-Friedrichshafen, Germany
| | - Victor Hernandez
- Department of Medical Physics, Hospital Sant Joan de Reus, IISPV, Tarragona, Spain
| | - Núria Jornet
- Servei de RadiofísicaiRadioprotecció, Hospital de la Santa CreuiSant Pau, Spain
| | - Catharine H. Clark
- Department of Medical Physics, Royal Surrey County Hospital, Guildford, Surrey, UK
- Metrology for Medical Physics (MEMPHYS), National Physical Laboratory, Teddington, Middlesex, UK
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Jafari S, Distefano G, Lee J, Gouldstone C, Mayles H, Jupp T, Nisbet A, Clark C. Feasibility study of silica bead thermoluminescence detectors (TLDs) in an external radiotherapy dosimetry audit programme. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Palmer AL, Nash D, Kearton JR, Jafari SM, Muscat S. A multicentre ‘end to end’ dosimetry audit of motion management (4DCT-defined motion envelope) in radiotherapy. Radiother Oncol 2017; 125:453-458. [DOI: 10.1016/j.radonc.2017.09.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/25/2017] [Accepted: 09/25/2017] [Indexed: 12/25/2022]
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A multi-centre dosimetry audit on advanced radiotherapy in lung as part of the Isotoxic IMRT study. Phys Imaging Radiat Oncol 2017. [DOI: 10.1016/j.phro.2017.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Miri N, Lehmann J, Legge K, Zwan BJ, Vial P, Greer PB. Remote dosimetric auditing for intensity modulated radiotherapy: A pilot study. Phys Imaging Radiat Oncol 2017. [DOI: 10.1016/j.phro.2017.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Jurado-Bruggeman D, Hernández V, Sáez J, Navarro D, Pino F, Martínez T, Alayrach ME, Ailleres N, Melero A, Jornet N. Multi-centre audit of VMAT planning and pre-treatment verification. Radiother Oncol 2017; 124:302-310. [DOI: 10.1016/j.radonc.2017.05.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/24/2017] [Accepted: 05/24/2017] [Indexed: 11/24/2022]
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Thomas RA, Bolt MA, Bass G, Nutbrown R, Chen T, Nisbet A, Clark CH. Radiotherapy reference dose audit in the United Kingdom by the National Physical Laboratory: 20 years of consistency and improvements. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2017. [DOI: 10.1016/j.phro.2017.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Challenges in calculation of the gamma index in radiotherapy – Towards good practice. Phys Med 2017; 36:1-11. [DOI: 10.1016/j.ejmp.2017.03.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/07/2017] [Accepted: 03/05/2017] [Indexed: 11/19/2022] Open
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Miri N, Lehmann J, Legge K, Vial P, Greer PB. Virtual EPID standard phantom audit (VESPA) for remote IMRT and VMAT credentialing. Phys Med Biol 2017; 62:4293-4299. [PMID: 28248642 DOI: 10.1088/1361-6560/aa63df] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A virtual EPID standard phantom audit (VESPA) has been implemented for remote auditing in support of facility credentialing for clinical trials using IMRT and VMAT. VESPA is based on published methods and a clinically established IMRT QA procedure, here extended to multi-vendor equipment. Facilities are provided with comprehensive instructions and CT datasets to create treatment plans. They deliver the treatment directly to their EPID without any phantom or couch in the beam. In addition, they deliver a set of simple calibration fields per instructions. Collected EPID images are uploaded electronically. In the analysis, the dose is projected back into a virtual cylindrical phantom. 3D gamma analysis is performed. 2D dose planes and linear dose profiles are provided and can be considered when needed for clarification. In addition, using a virtual flat-phantom, 2D field-by-field or arc-by-arc gamma analyses are performed. Pilot facilities covering a range of planning and delivery systems have performed data acquisition and upload successfully. Advantages of VESPA are (1) fast turnaround mainly driven by the facility's capability of providing the requested EPID images, (2) the possibility for facilities performing the audit in parallel, as there is no need to wait for a phantom, (3) simple and efficient credentialing for international facilities, (4) a large set of data points, and (5) a reduced impact on resources and environment as there is no need to transport heavy phantoms or audit staff. Limitations of the current implementation of VESPA for trials credentialing are that it does not provide absolute dosimetry, therefore a Level I audit is still required, and that it relies on correctly delivered open calibration fields, which are used for system calibration. The implemented EPID based IMRT and VMAT audit system promises to dramatically improve credentialing efficiency for clinical trials and wider applications.
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Affiliation(s)
- Narges Miri
- School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, Australia
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Eaton DJ, Tyler J, Backshall A, Bernstein D, Carver A, Gasnier A, Henderson J, Lee J, Patel R, Tsang Y, Yang H, Zotova R, Wells E. An external dosimetry audit programme to credential static and rotational IMRT delivery for clinical trials quality assurance. Phys Med 2017; 35:25-30. [PMID: 28236559 DOI: 10.1016/j.ejmp.2017.02.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/23/2017] [Accepted: 02/14/2017] [Indexed: 11/19/2022] Open
Affiliation(s)
- David J Eaton
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK.
| | - Justine Tyler
- RTTQA, Royal Marsden Hospital, Fulham Road, London, UK
| | | | | | | | - Anne Gasnier
- RTTQA, Royal Marsden Hospital, Fulham Road, London, UK
| | | | - Jonathan Lee
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK
| | - Rushil Patel
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK
| | - Yatman Tsang
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK
| | - Huiqi Yang
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK
| | - Rada Zotova
- Radiotherapy Trials QA Group (RTTQA), Mount Vernon Hospital, Northwood, UK
| | - Emma Wells
- RTTQA, Royal Marsden Hospital, Fulham Road, London, UK
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Distefano G, Lee J, Jafari S, Gouldstone C, Baker C, Mayles H, Clark CH. A national dosimetry audit for stereotactic ablative radiotherapy in lung. Radiother Oncol 2017; 122:406-410. [PMID: 28117079 DOI: 10.1016/j.radonc.2016.12.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 11/16/2016] [Accepted: 12/05/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE A UK national dosimetry audit was carried out to assess the accuracy of Stereotactic Ablative Body Radiotherapy (SABR) lung treatment delivery. METHODS AND MATERIALS This mail-based audit used an anthropomorphic thorax phantom containing nine alanine pellets positioned in the lung region for dosimetry, as well as EBT3 film in the axial plane for isodose comparison. Centres used their local planning protocol/technique, creating 27 SABR plans. A range of delivery techniques including conformal, volumetric modulated arc therapy (VMAT) and Cyberknife (CK) were used with six different calculation algorithms (collapsed cone, superposition, pencil-beam (PB), AAA, Acuros and Monte Carlo). RESULTS The mean difference between measured and calculated dose (excluding PB results) was 0.4±1.4% for alanine and 1.4±3.4% for film. PB differences were -6.1% and -12.9% respectively. The median of the absolute maximum isodose-to-isodose distances was 3mm (-6mm to 7mm) and 5mm (-10mm to +19mm) for the 100% and 50% isodose lines respectively. CONCLUSIONS Alanine and film is an effective combination for verifying dosimetric and geometric accuracy. There were some differences across dose algorithms, and geometric accuracy was better for VMAT and CK compared with conformal techniques. The alanine dosimetry results showed that planned and delivered doses were within ±3.0% for 25/27 SABR plans.
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Affiliation(s)
- Gail Distefano
- Department of Medical Physics, Royal Surrey County Hospital NHS Trust, Guildford, UK.
| | - Jonny Lee
- Clatterbridge Cancer Centre, Liverpool, UK
| | - Shakardokht Jafari
- Department of Physics, University of Surrey, Guildford, UK; Radiology Department, Faculty of Medicine, Kabul Medical University, Afghanistan
| | | | - Colin Baker
- Clatterbridge Cancer Centre, Liverpool, UK; Radiotherapy Physics, Royal Berkshire NHS Foundation Trust, Reading, UK
| | | | - Catharine H Clark
- Department of Medical Physics, Royal Surrey County Hospital NHS Trust, Guildford, UK; Department of Physics, University of Surrey, Guildford, UK; National Physical Laboratory, Teddington, UK
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Abolaban F, Zaman S, Cashmore J, Nisbet A, Clark C. Changes in Patterns of Intensity-modulated Radiotherapy Verification and Quality Assurance in the UK. Clin Oncol (R Coll Radiol) 2016; 28:e28-34. [DOI: 10.1016/j.clon.2016.01.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 12/08/2015] [Accepted: 01/05/2016] [Indexed: 10/22/2022]
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Lafond C, Chiavassa S, Bertaut C, Boussion N, Chapel N, Chapron L, Coste F, Crespin S, Dy G, Faye PA, Leleu C, Bouvier J, Madec L, Mesgouez J, Palisson J, Vela A, Delpon G. DEMAT: A multi-institutional dosimetry audit of rotational and static intensity-modulated radiotherapy. Phys Med 2016; 32:664-70. [DOI: 10.1016/j.ejmp.2016.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/03/2016] [Accepted: 04/18/2016] [Indexed: 10/21/2022] Open
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McGarry CK, Agnew CE, Hussein M, Tsang Y, Hounsell AR, Clark CH. The use of log file analysis within VMAT audits. Br J Radiol 2016; 89:20150489. [PMID: 27072390 DOI: 10.1259/bjr.20150489] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE This work investigated the delivery accuracy of different Varian linear accelerator models using log file-derived multileaf collimator (MLC) root mean square (RMS) values. METHODS Seven centres independently created a plan on the same virtual phantom using their own planning system, and the log files were analyzed following delivery of the plan in each centre to assess MLC positioning accuracy. A single standard plan was also delivered by the seven centres to remove variations in complexity, and the log files were analyzed for Varian TrueBeams and Clinacs (2300IX or 2100CD models). RESULTS Varian TrueBeam accelerators had better MLC positioning accuracy (<1.0 mm) than the 2300IX (<2.5 mm) following delivery of the plans created by each centre and also the standard plan. In one case, log files provided evidence that reduced delivery accuracy was not associated with the linear accelerator model but was due to planning issues. CONCLUSION Log files are useful in identifying differences between linear accelerator models and isolate errors during end-to-end testing in volumetric-modulated arc therapy (VMAT) audits. Log file analysis can rapidly eliminate the machine delivery from the process and divert attention with confidence to other aspects. ADVANCES IN KNOWLEDGE Log file evaluation was shown to be an effective method to rapidly verify satisfactory treatment delivery when a dosimetric evaluation fails during end-to-end dosimetry audits. MLC RMS values for Varian TrueBeams were shown to be much smaller than those for Varian Clinacs for VMAT deliveries.
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Affiliation(s)
- Conor K McGarry
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK.,2 Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Christina E Agnew
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK
| | - Mohammad Hussein
- 3 Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.,4 Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK
| | - Yatman Tsang
- 5 RTTQA Group, Mount Vernon Hospital, Northwood, UK
| | - Alan R Hounsell
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK.,2 Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Catharine H Clark
- 3 Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.,4 Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK.,6 Radiation Dosimetry Group, National Physical Laboratory, Teddington, UK
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Dimitriadis A, Kirkby KJ, Nisbet A, Clark CH. Current status of cranial stereotactic radiosurgery in the UK. Br J Radiol 2015; 89:20150452. [PMID: 26689091 DOI: 10.1259/bjr.20150452] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE To investigate and benchmark the current clinical and dosimetric practices in stereotactic radiosurgery (SRS) in the UK. METHODS A detailed questionnaire was sent to 70 radiotherapy centres in the UK. 97% (68/70) of centres replied between June and December 2014. RESULTS 21 centres stated that they are practising SRS, and a further 12 centres plan to start SRS by the end of 2016. The most commonly treated indications are brain metastases and acoustic neuromas. A large range of prescription isodoses that range from 45% to 100% between different radiotherapy centres was seen. Ionization chambers and solid-water phantoms are used by the majority of centres for patient-specific quality assurance, and thermoplastic masks for patient immobilization are more commonly used than fixed stereotactic frames. The majority of centres perform orthogonal kilovoltage X-rays for localization before and during delivery. The acceptable setup accuracy reported ranges from 0.1 to 2 mm with a mean of 0.8 mm. CONCLUSION SRS has been increasing in use in the UK and will continue to increase in the next 2 years. There is no current consensus between SRS centres as a whole, or even between SRS centres with the same equipment, on the practices followed. This indicates the need for benchmarking and standardization in SRS practices within the UK. ADVANCES IN KNOWLEDGE This article outlines the current practices in SRS and provides a benchmark for reference and comparison with future research in this technique.
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Affiliation(s)
- Alexis Dimitriadis
- 1 Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK.,2 Department of Medical Physics, Royal County Hospital NHS Foundation Trust, Guildford, UK.,3 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
| | - Karen J Kirkby
- 4 Manchester Academic Science, Institute of Cancer Sciences, University of Manchester, Manchester, UK.,5 The Christie NHS Foundation Trust, Manchester, UK
| | - Andrew Nisbet
- 1 Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK.,2 Department of Medical Physics, Royal County Hospital NHS Foundation Trust, Guildford, UK
| | - Catharine H Clark
- 2 Department of Medical Physics, Royal County Hospital NHS Foundation Trust, Guildford, UK.,3 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
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Linking log files with dosimetric accuracy – A multi-institutional study on quality assurance of volumetric modulated arc therapy. Radiother Oncol 2015; 117:407-11. [DOI: 10.1016/j.radonc.2015.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 09/22/2015] [Accepted: 11/11/2015] [Indexed: 11/17/2022]
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Muren LP, Jornet N, Georg D, Garcia R, Thwaites DI. Improving radiotherapy through medical physics developments. Radiother Oncol 2015; 117:403-6. [DOI: 10.1016/j.radonc.2015.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 11/19/2015] [Indexed: 01/21/2023]
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40
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Beierholm A, Behrens C, Andersen C. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy. RADIAT MEAS 2015. [DOI: 10.1016/j.radmeas.2015.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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McGarry CK, Agnew CE, Hussein M, Tsang Y, McWilliam A, Hounsell AR, Clark CH. The role of complexity metrics in a multi-institutional dosimetry audit of VMAT. Br J Radiol 2015; 89:20150445. [PMID: 26511276 DOI: 10.1259/bjr.20150445] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To demonstrate the benefit of complexity metrics such as the modulation complexity score (MCS) and monitor units (MUs) in multi-institutional audits of volumetric-modulated arc therapy (VMAT) delivery. METHODS 39 VMAT treatment plans were analysed using MCS and MU. A virtual phantom planning exercise was planned and independently measured using the PTW Octavius(®) phantom and seven29(®) 2D array (PTW-Freiburg GmbH, Freiburg, Germany). MCS and MU were compared with the median gamma index pass rates (2%/2 and 3%/3 mm) and plan quality. The treatment planning systems (TPS) were grouped by VMAT modelling being specifically designed for the linear accelerator manufacturer's own treatment delivery system (Type 1) or independent of vendor for VMAT delivery (Type 2). Differences in plan complexity (MCS and MU) between TPS types were compared. RESULTS For Varian(®) linear accelerators (Varian(®) Medical Systems, Inc., Palo Alto, CA), MCS and MU were significantly correlated with gamma pass rates. Type 2 TPS created poorer quality, more complex plans with significantly higher MUs and MCS than Type 1 TPS. Plan quality was significantly correlated with MU for Type 2 plans. A statistically significant correlation was observed between MU and MCS for all plans (R = -0.84, p < 0.01). CONCLUSION MU and MCS have a role in assessing plan complexity in audits along with plan quality metrics. Plan complexity metrics give some indication of plan deliverability but should be analysed with plan quality. ADVANCES IN KNOWLEDGE Complexity metrics were investigated for a national rotational audit involving 34 institutions and they showed value. The metrics found that more complex plans were created for planning systems which were independent of vendor for VMAT delivery.
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Affiliation(s)
- Conor K McGarry
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK.,2 Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Christina E Agnew
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK
| | - Mohammad Hussein
- 3 Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.,4 Department of Physics, University of Surrey, Guildford, UK
| | - Yatman Tsang
- 5 RTTQA Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - Alan McWilliam
- 6 Medical Physics and Engineering Department, Christie Hospital NHS Foundation Trust, Manchester, UK
| | - Alan R Hounsell
- 1 Radiotherapy Physics, Belfast Health and Social Care Trust, Belfast, UK.,2 Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Catharine H Clark
- 3 Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.,4 Department of Physics, University of Surrey, Guildford, UK.,7 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
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42
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Eaton DJ, Bolton S, Thomas RAS, Clark CH. Inter-departmental dosimetry audits - development of methods and lessons learned. J Med Phys 2015; 40:183-9. [PMID: 26865753 PMCID: PMC4728888 DOI: 10.4103/0971-6203.170791] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/05/2015] [Accepted: 08/05/2015] [Indexed: 11/10/2022] Open
Abstract
External dosimetry audits give confidence in the safe and accurate delivery of radiotherapy. In the United Kingdom, such audits have been performed for almost 30 years. From the start, they included clinically relevant conditions, as well as reference machine output. Recently, national audits have tested new or complex techniques, but these methods are then used in regional audits by a peer-to-peer approach. This local approach builds up the radiotherapy community, facilitates communication, and brings synergy to medical physics.
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Affiliation(s)
- David J. Eaton
- Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, London, UK
| | - Steve Bolton
- Inter-departmental Audit Group, Institute of Physics and Engineering in Medicine, York, UK
- Department of Medical Physics and Engineering, Christie Hospital, Manchester, UK
| | | | - Catharine H. Clark
- Radiation Dosimetry Group, National Physical Laboratory, London, UK
- Department of Medical Physics, Royal Surrey County Hospital, Guildford, UK
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Clark CH, Aird EGA, Bolton S, Miles EA, Nisbet A, Snaith JAD, Thomas RAS, Venables K, Thwaites DI. Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials. Br J Radiol 2015; 88:20150251. [PMID: 26329469 DOI: 10.1259/bjr.20150251] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed.
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Affiliation(s)
- Catharine H Clark
- 1 Department of Medical Physics, Royal Surrey County Hospital, Guildford, Surrey, UK.,2 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
| | - Edwin G A Aird
- 3 RTTQA Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - Steve Bolton
- 4 Medical Physics and Engineering Department, Christie Hospital NHS Foundation Trust, Manchester, UK.,5 Institute of Physics and Engineering in Medicine, York, UK
| | | | - Andrew Nisbet
- 1 Department of Medical Physics, Royal Surrey County Hospital, Guildford, Surrey, UK.,6 Department of Physics, University of Surrey, Guildford, UK
| | - Julia A D Snaith
- 2 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
| | - Russell A S Thomas
- 2 Radiation Dosimetry Group, National Physical Laboratory, Teddington, Middlesex, UK
| | - Karen Venables
- 3 RTTQA Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - David I Thwaites
- 7 Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia
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Eaton DJ. Electronic brachytherapy--current status and future directions. Br J Radiol 2015; 88:20150002. [PMID: 25748070 PMCID: PMC4628482 DOI: 10.1259/bjr.20150002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/28/2015] [Accepted: 03/05/2015] [Indexed: 12/17/2022] Open
Abstract
In the past decade, electronic brachytherapy (EB) has emerged as an attractive modality for the treatment of skin lesions and intraoperative partial breast irradiation, as well as finding wider applications in intracavitary and interstitial sites. These miniature X-ray sources, which operate at low kilovoltage energies (<100 kV), have reduced shielding requirements and inherent portability, therefore can be used outside the traditional realms of the radiotherapy department. However, steep dose gradients and increased sensitivity to inhomogeneities challenge accurate dosimetry. Secondly, ease of use does not mitigate the need for close involvement by medical physics experts and consultant oncologists. Finally, further studies are needed to relate the more heterogeneous dose distributions to clinical outcomes. With these provisos, the practical convenience of EB strongly suggests that it will become an established option for selected patients, not only in radiotherapy departments but also in a range of operating theatres and clinics around the world.
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Affiliation(s)
- D J Eaton
- NCRI Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, London, UK
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45
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A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment. Radiother Oncol 2015; 114:264-71. [DOI: 10.1016/j.radonc.2014.12.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 11/22/2022]
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