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Oliver-Cañamás L, Vijande J, Candela-Juan C, Gimeno-Olmos J, Pujades-Claumarchirant MC, Rovira-Escutia JJ, Ballester F, Perez-Calatayud J. A User-Friendly System for Mailed Dosimetric Audits of 192Ir or 60Co HDR Brachytherapy Sources. Cancers (Basel) 2023; 15:cancers15092484. [PMID: 37173950 PMCID: PMC10177083 DOI: 10.3390/cancers15092484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVES The main goal of this work is to design and characterize a user-friendly methodology to perform mailed dosimetric audits in high dose rate (HDR) brachytherapy for systems using either Iridium-192 (192Ir) or Cobalt-60 (60Co) sources. METHODS A solid phantom was designed and manufactured with four catheters and a central slot to place one dosimeter. Irradiations with an Elekta MicroSelectron V2 for 192Ir, and with a BEBIG Multisource for 60Co were performed for its characterization. For the dose measurements, nanoDots, a type of optically stimulated luminescent dosimeters (OSLDs), were characterized. Monte Carlo (MC) simulations were performed to evaluate the scatter conditions of the irradiation set-up and to study differences in the photon spectra of different 192Ir sources (Microselectron V2, Flexisource, BEBIG Ir2.A85-2 and Varisource VS2000) reaching the dosimeter in the irradiation set-up. RESULTS MC simulations indicate that the surface material on which the phantom is supported during the irradiations does not affect the absorbed dose in the nanoDot. Generally, differences below 5% were found in the photon spectra reaching the detector when comparing the Microselectron V2, the Flexisource and the BEBIG models. However, differences up to 20% are observed between the V2 and the Varisource VS2000 models. The calibration coefficients and the uncertainty in the dose measurement were evaluated. CONCLUSIONS The system described here is able to perform dosimetric audits in HDR brachytherapy for systems using either 192Ir or 60Co sources. No significant differences are observed between the photon spectra reaching the detector for the MicroSelectron V2, the Flexisource and the BEBIG 192Ir sources. For the Varisource VS2000, a higher uncertainty is considered in the dose measurement to allow for the nanoDot response.
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Affiliation(s)
- Laura Oliver-Cañamás
- Servei de Radiofísica i Protecció Radiològica, Consorci Hospitalari Provincial de Castelló (CHPC), 12002 Castelló de la Plana, Spain
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), 46100 Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Instituto de Investigación Sanitaria La Fe (IIS-La Fe), Universitat de Valencia (UV), 46026 València, Spain
- Instituto de Física Corpuscular, Instituto de Física Corpuscular-IFIC (UV-CSIC), 46100 Burjassot, Spain
| | | | - Jose Gimeno-Olmos
- Unitat de Radiofísica, Servei d'Oncologia Radioteràpica, Hospital Universitari i Politècnic La Fe, 46026 València, Spain
| | | | - Juan J Rovira-Escutia
- Servei de Radiofísica i Protecció Radiològica, Consorci Hospital General Universitari de València, 46014 València, Spain
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), 46100 Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Instituto de Investigación Sanitaria La Fe (IIS-La Fe), Universitat de Valencia (UV), 46026 València, Spain
| | - Jose Perez-Calatayud
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Instituto de Investigación Sanitaria La Fe (IIS-La Fe), Universitat de Valencia (UV), 46026 València, Spain
- Unitat de Radiofísica, Servei d'Oncologia Radioteràpica, Hospital Universitari i Politècnic La Fe, 46026 València, Spain
- Hospital Clínica Benidorm, 03501 Benidorm, Spain
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Biglin ER, Aitkenhead AH, Price GJ, Chadwick AL, Santina E, Williams KJ, Kirkby KJ. A preclinical radiotherapy dosimetry audit using a realistic 3D printed murine phantom. Sci Rep 2022; 12:6826. [PMID: 35474242 PMCID: PMC9042835 DOI: 10.1038/s41598-022-10895-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 04/05/2022] [Indexed: 11/08/2022] Open
Abstract
Preclinical radiation research lacks standardized dosimetry procedures that provide traceability to a primary standard. Consequently, ensuring accuracy and reproducibility between studies is challenging. Using 3D printed murine phantoms we undertook a dosimetry audit of Xstrahl Small Animal Radiation Research Platforms (SARRPs) installed at 7 UK centres. The geometrically realistic phantom accommodated alanine pellets and Gafchromic EBT3 film for simultaneous measurement of the dose delivered and the dose distribution within a 2D plane, respectively. Two irradiation scenarios were developed: (1) a 10 × 10 mm2 static field targeting the pelvis, and (2) a 5 × 5 mm2 90° arc targeting the brain. For static fields, the absolute difference between the planned dose and alanine measurement across all centres was 4.1 ± 4.3% (mean ± standard deviation), with an overall range of - 2.3 to 10.5%. For arc fields, the difference was - 1.2% ± 6.1%, with a range of - 13.1 to 7.7%. EBT3 dose measurements were greater than alanine by 2.0 ± 2.5% and 3.5 ± 6.0% (mean ± standard deviation) for the static and arc fields, respectively. 2D dose distributions showed discrepancies to the planned dose at the field edges. The audit demonstrates that further work on preclinical radiotherapy quality assurance processes is merited.
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Affiliation(s)
- Emma R Biglin
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK.
| | - Adam H Aitkenhead
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - Gareth J Price
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK
- The Christie NHS Foundation Trust, Manchester, UK
| | - Amy L Chadwick
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK
- The Christie NHS Foundation Trust, Manchester, UK
| | - Elham Santina
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK
- The Christie NHS Foundation Trust, Manchester, UK
| | - Kaye J Williams
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Karen J Kirkby
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3rd floor Proton Beam Therapy Centre, Oak Road, Manchester, M20 4BX, UK
- The Christie NHS Foundation Trust, Manchester, UK
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Ayala Alvarez DS, Watson PGF, Popovic M, Heng VJ, Evans MDC, Seuntjens J. Monte Carlo calculation of the TG-43 dosimetry parameters for the INTRABEAM source with spherical applicators. Phys Med Biol 2021; 66. [PMID: 34663769 DOI: 10.1088/1361-6560/ac309f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/18/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The relative TG-43 dosimetry parameters of the INTRABEAM (Carl Zeiss Meditec AG, Jena, Germany) bare probe were recently reported by Ayala Alvarezet al(2020Phys. Med. Biol.65245041). The current study focuses on the dosimetry characterization of the INTRABEAM source with the eight available spherical applicators according to the TG-43 formalism using Monte Carlo (MC) simulations. APPROACH This report includes the calculated dose-rate conversion coefficients that determine the absolute dose rate to water at a reference point of 10 mm from the applicator surface, based on calibration air-kerma rate measurements at 50 cm from the source on its transverse plane. Since the air-kerma rate measurements are not yet provided from a standards laboratory for the INTRABEAM, the values in the present study were calculated with MC. This approach is aligned with other works in the search for standardization of the dosimetry of electronic brachytherapy sources. As a validation of the MC model, depth dose calculations along the source axis were compared with calibration data from the source manufacturer. MAIN RESULTS The calculated dose-rate conversion coefficients were 434.0 for the bare probe, and 683.5, 548.3, 449.9, 376.5, 251.0, 225.6, 202.8, and 182.6 for the source with applicators of increasing diameter from 15 to 50 mm, respectively. The radial dose and the 2D anisotropy functions of the TG-43 formalism were also obtained and tabulated in this document. SIGNIFICANCE This work presents the data required by a treatment planning system for the characterization of the INTRABEAM system in the context of intraoperative radiotherapy applications.
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Affiliation(s)
| | - Peter G F Watson
- Medical Physics Unit, McGill University and Cedars Cancer Center, Montreal, Canada
| | - Marija Popovic
- Medical Physics Unit, McGill University and Cedars Cancer Center, Montreal, Canada
| | - Veng Jean Heng
- Medical Physics Unit, McGill University and Cedars Cancer Center, Montreal, Canada
| | - Michael D C Evans
- Medical Physics Unit, McGill University and Cedars Cancer Center, Montreal, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University and Cedars Cancer Center, Montreal, Canada
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Monte Carlo based analysis and evaluation of energy spectrum for low-kV IORT spherical applicators. Z Med Phys 2020; 30:60-69. [DOI: 10.1016/j.zemedi.2019.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 08/15/2019] [Accepted: 08/26/2019] [Indexed: 02/06/2023]
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Martin CJ, Temperton DH, Jupp T, Hughes A. IPEM topical report: personal dose monitoring requirements in healthcare. ACTA ACUST UNITED AC 2019; 64:035008. [DOI: 10.1088/1361-6560/aafa3f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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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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Burrows T, Earner B, Faulkner P, Dancer N. Micro-commissioning of an INTRABEAM Intraoperative Radiotherapy (IORT) X-ray source (XRS) using EBT3 Gafchromic film in conjunction with multichannel film dosimetry and Matlab analysis. Phys Med 2016. [DOI: 10.1016/j.ejmp.2015.07.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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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: 42] [Impact Index Per Article: 4.7] [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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Misson-Yates S, Gonzalez R, McGovern M, Greener A. Comparative dosimetry study of three UK centres implementing total skin electron treatment through external audit. Br J Radiol 2015; 88:20140723. [PMID: 25761213 DOI: 10.1259/bjr.20140723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE This article describes the external audit measurements conducted in two UK centres implementing total skin electron beam therapy (TSEBT) and the results obtained. METHODS Measurements of output, energy, beam flatness and symmetry at a standard distance (95 or 100 cm SSD) were performed using a parallel plate chamber in solid water. Similarly, output and energy measurements were also performed at the treatment plane for single and dual fields. Clinical simulations were carried out using thermoluminescent dosemeters (TLDs) and Gafchromic® film (International Specialty Products, Wayne, NJ) on an anthropomorphic phantom. RESULTS Extended distance measurements confirmed that local values for the beam dosimetry at Centres A and B were within 2% for outputs and 1-mm agreement of the expected depth at which the dose is 50% of the maximum for the depth-dose curve in water (R50,D) value. Clinical simulation using TLDs) showed an agreement of -1.6% and -6.7% compared with the expected mean trunk dose for each centre, respectively, and a variation within 10% (±1 standard deviation) across the trunk. The film results confirmed that the delivery of the treatment technique at each audited centre complies with the European Organisation for Research and Treatment of Cancer recommendations. CONCLUSION This audit methodology has proven to be a successful way to confirm the agreement of dosimetric parameters for TSEBT treatments at both audited centres and could serve as the basis for an audit template to be used by other audit groups. ADVANCES IN KNOWLEDGE TSEBT audits are not established in the UK owing to a limited number of centres carrying out the treatment technique. This article describes the audits performed at two UK centres prior to their clinical implementation.
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Affiliation(s)
- S Misson-Yates
- Medical Physics Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Abstract
Dosimetric audit is required for the improvement of patient safety in radiotherapy and to aid optimization of treatment. The reassurance that treatment is being delivered in line with accepted standards, that delivered doses are as prescribed and that quality improvement is enabled is as essential for brachytherapy as it is for the more commonly audited external beam radiotherapy. Dose measurement in brachytherapy is challenging owing to steep dose gradients and small scales, especially in the context of an audit. Several different approaches have been taken for audit measurement to date: thimble and well-type ionization chambers, thermoluminescent detectors, optically stimulated luminescence detectors, radiochromic film and alanine. In this work, we review all of the dosimetric brachytherapy audits that have been conducted in recent years, look at current audits in progress and propose required directions for brachytherapy dosimetric audit in the future. The concern over accurate source strength measurement may be essentially resolved with modern equipment and calibration methods, but brachytherapy is a rapidly developing field and dosimetric audit must keep pace.
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Affiliation(s)
- A L Palmer
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, UK
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Hill R, Healy B, Holloway L, Kuncic Z, Thwaites D, Baldock C. Advances in kilovoltage x-ray beam dosimetry. Phys Med Biol 2014; 59:R183-231. [DOI: 10.1088/0031-9155/59/6/r183] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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