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Piotrowski M, Maras P, Kozicki M. On the Use of the Fricke-Pluronic F-127 Gel Dosimeter for Radiation Isocenter Testing of a Medical Linear Accelerator. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1521. [PMID: 38612035 PMCID: PMC11012804 DOI: 10.3390/ma17071521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/19/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024]
Abstract
This work presents a Fricke-XO-Pluronic F-127 2D radiochromic dosimeter with a flat-bed scanner for 2D reading and a dedicated data processing software package as a tool for performing coincidence testing of the radiation and mechanical isocenter of a medical accelerator. The optimal irradiation parameters were determined as follows: monitor units per beam and multi-leaf collimator gap, which are ≤750-≤2500 MU and 2-5 mm, respectively, for a cuboidal container with dimensions of 12 × 12 × 0.3 cm3. Despite the diffusion of Fe3+ ions occurring during irradiation, 2D reading can be performed at least 3 h after irradiation, without affecting the calculation performance of the coincidence test. The test was successfully performed for various irradiation settings. Overall, the Fricke-XO-Pluronic F-127 dosimeter has proven to be a potential tool for the coincidence testing of medical accelerators.
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Affiliation(s)
- Michał Piotrowski
- Department of Mechanical Engineering, Informatics and Chemistry of Polymer Materials, Faculty of Materials Technologies and Textile Design, Lodz University of Technology, 90-543 Lodz, Poland;
| | - Piotr Maras
- Department of Radiotherapy Planning, Copernicus Hospital, 93-513 Lodz, Poland;
| | - Marek Kozicki
- Department of Mechanical Engineering, Informatics and Chemistry of Polymer Materials, Faculty of Materials Technologies and Textile Design, Lodz University of Technology, 90-543 Lodz, Poland;
- GeVero Co., 90-980 Lodz, Poland
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2
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Karger CP, Elter A, Dorsch S, Mann P, Pappas E, Oldham M. Validation of complex radiotherapy techniques using polymer gel dosimetry. Phys Med Biol 2024; 69:06TR01. [PMID: 38330494 DOI: 10.1088/1361-6560/ad278f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
Modern radiotherapy delivers highly conformal dose distributions to irregularly shaped target volumes while sparing the surrounding normal tissue. Due to the complex planning and delivery techniques, dose verification and validation of the whole treatment workflow by end-to-end tests became much more important and polymer gel dosimeters are one of the few possibilities to capture the delivered dose distribution in 3D. The basic principles and formulations of gel dosimetry and its evaluation methods are described and the available studies validating device-specific geometrical parameters as well as the dose delivery by advanced radiotherapy techniques, such as 3D-CRT/IMRT and stereotactic radiosurgery treatments, the treatment of moving targets, online-adaptive magnetic resonance-guided radiotherapy as well as proton and ion beam treatments, are reviewed. The present status and limitations as well as future challenges of polymer gel dosimetry for the validation of complex radiotherapy techniques are discussed.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
| | - Stefan Dorsch
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Evangelos Pappas
- Radiology & Radiotherapy Sector, Department of Biomedical Sciences, University of West Attica, Athens, Greece
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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Knäusl B, Belotti G, Bertholet J, Daartz J, Flampouri S, Hoogeman M, Knopf AC, Lin H, Moerman A, Paganelli C, Rucinski A, Schulte R, Shimizu S, Stützer K, Zhang X, Zhang Y, Czerska K. A review of the clinical introduction of 4D particle therapy research concepts. Phys Imaging Radiat Oncol 2024; 29:100535. [PMID: 38298885 PMCID: PMC10828898 DOI: 10.1016/j.phro.2024.100535] [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: 10/11/2023] [Revised: 12/12/2023] [Accepted: 01/04/2024] [Indexed: 02/02/2024] Open
Abstract
Background and purpose Many 4D particle therapy research concepts have been recently translated into clinics, however, remaining substantial differences depend on the indication and institute-related aspects. This work aims to summarise current state-of-the-art 4D particle therapy technology and outline a roadmap for future research and developments. Material and methods This review focused on the clinical implementation of 4D approaches for imaging, treatment planning, delivery and evaluation based on the 2021 and 2022 4D Treatment Workshops for Particle Therapy as well as a review of the most recent surveys, guidelines and scientific papers dedicated to this topic. Results Available technological capabilities for motion surveillance and compensation determined the course of each 4D particle treatment. 4D motion management, delivery techniques and strategies including imaging were diverse and depended on many factors. These included aspects of motion amplitude, tumour location, as well as accelerator technology driving the necessity of centre-specific dosimetric validation. Novel methodologies for X-ray based image processing and MRI for real-time tumour tracking and motion management were shown to have a large potential for online and offline adaptation schemes compensating for potential anatomical changes over the treatment course. The latest research developments were dominated by particle imaging, artificial intelligence methods and FLASH adding another level of complexity but also opportunities in the context of 4D treatments. Conclusion This review showed that the rapid technological advances in radiation oncology together with the available intrafractional motion management and adaptive strategies paved the way towards clinical implementation.
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Affiliation(s)
- Barbara Knäusl
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Gabriele Belotti
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Jenny Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - Juliane Daartz
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Mischa Hoogeman
- Department of Medical Physics & Informatics, HollandPTC, Delft, The Netherlands
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, The Netherlands
| | - Antje C Knopf
- Institut für Medizintechnik und Medizininformatik Hochschule für Life Sciences FHNW, Muttenz, Switzerland
| | - Haibo Lin
- New York Proton Center, New York, NY, USA
| | - Astrid Moerman
- Department of Medical Physics & Informatics, HollandPTC, Delft, The Netherlands
| | - Chiara Paganelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Antoni Rucinski
- Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow, Poland
| | - Reinhard Schulte
- Division of Biomedical Engineering Sciences, School of Medicine, Loma Linda University
| | - Shing Shimizu
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kristin Stützer
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
| | - Xiaodong Zhang
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Katarzyna Czerska
- Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI, Switzerland
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Schieferecke J, Gantz S, Hoffmann A, Pawelke J. Investigation of contrast mechanisms for MRI phase signal-based proton beam visualization in water phantoms. Magn Reson Med 2023; 90:1776-1788. [PMID: 37345700 DOI: 10.1002/mrm.29752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/23/2023]
Abstract
PURPOSE The low sensitivity and limitation to water phantoms of convection-dependent MRI magnitude signal-based proton beam visualization hinder its in vivo applicability in MR-integrated proton beam therapy. The purpose of the present study was, therefore, to assess possible contrast mechanisms for MRI phase signal-based proton beam visualization that can potentially be exploited to enhance the sensitivity of the method and extend its applicability to tissue materials. METHODS To assess whether proton beam-induced magnetic field perturbations, changes in material susceptibility or convection result in detectable changes in the MRI phase signal, water phantom characteristics, experiment timing, and imaging parameters were varied in combined irradiation and imaging experiments using a time-of-flight angiography pulse sequence on a prototype in-beam MRI scanner. Velocity encoding was used to further probe and quantify beam-induced convection. RESULTS MRI phase signal-based proton beam visualization proved feasible. The observed phase difference contrast was evoked by beam-induced buoyant convection with flow velocities in the mm/s range. Proton beam-induced magnetic field perturbations or changes in magnetic susceptibility did not influence the MRI phase signal. Velocity encoding was identified as a means to enhance the detection sensitivity. CONCLUSION Because the MRI phase difference contrast observed during proton beam irradiation of water phantoms is caused by beam-induced convection, this method will unlikely be transferable to tightly compartmentalized tissue wherein flow effects are restricted. However, strong velocity encoded pulse sequences were identified as promising candidates for the future development of MRI-based methods for water phantom-based geometric quality assurance in MR-integrated proton beam therapy.
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Affiliation(s)
- Juliane Schieferecke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Sebastian Gantz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Aswin Hoffmann
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
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Schieferecke J, Gantz S, Karsch L, Pawelke J, Hoffmann A. MRI magnitude signal-based proton beam visualisation in water phantoms reflects composite effects of beam-induced buoyant convection and radiation chemistry. Phys Med Biol 2023; 68:185002. [PMID: 37607554 DOI: 10.1088/1361-6560/acf2e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
Objective. Local magnetic resonance (MR) signal loss was previously observed during proton beam irradiation of free-floating water phantoms at ambient temperature using a research prototype in-beam magnetic resonance imaging (MRI) scanner. The emergence of this MR signal loss was hypothesised to be dependent on beam-induced convection. The aim of this study was therefore to unravel whether physical conditions allowing the development of convection must prevail for the beam-induced MRI signatures to emerge.Approach. The convection dependence of MRI magnitude signal-based proton beam visualisation was investigated in combined irradiation and imaging experiments using a gradient echo (GE)-based time-of-flight (ToF) angiography pulse sequence, which was first tested for its suitability for proton beam visualisation in free-floating water phantoms at ambient temperature. Subsequently, buoyant convection was selectively suppressed in water phantoms using either mechanical barriers or temperature control of water expansivity. The underlying contrast mechanism was further assessed using sagittal imaging and variation of T1 relaxation time-weighting.Main results. In the absence of convection-driven water flow, weak beam-induced MR signal changes occurred, whereas strong changes did occur when convection was not mechanically or thermally inhibited. Moreover, the degree of signal loss was found to change with the variation of T1-weighting. Consequently, beam-induced MR signal loss in free-floating water phantoms at ambient temperature does not exclusively originate from buoyant convection, but is caused by local composite effects of beam-induced motion and radiation chemistry resulting in a local change in the water T1 relaxation time.Significance. The identification of ToF angiography sequence-based proton beam visualisation in water phantoms to result from composite effects of beam-induced motion and radiation chemistry represents the starting point for the future elucidation of the currently unexplained motion-based MRI contrast mechanism and the identification of the proton beam-induced material change causing T1 relaxation time lengthening.
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Affiliation(s)
- Juliane Schieferecke
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Sebastian Gantz
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Leonhard Karsch
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Jörg Pawelke
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Aswin Hoffmann
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Gantz S, Karsch L, Pawelke J, Peter J, Schellhammer S, Smeets J, van der Kraaij E, Hoffmann A. Direct visualization of proton beam irradiation effects in liquids by MRI. Proc Natl Acad Sci U S A 2023; 120:e2301160120. [PMID: 37252953 PMCID: PMC10265969 DOI: 10.1073/pnas.2301160120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/06/2023] [Indexed: 06/01/2023] Open
Abstract
The main advantage proton beams offer over photon beams in radiation therapy of cancer patients is the dose maximum at their finite range, yielding a reduction in the dose deposited in healthy tissues surrounding the tumor. Since no direct method exists to measure the beam's range during dose delivery, safety margins around the tumor are applied, compromising the dose conformality and reducing the targeting accuracy. Here, we demonstrate that online MRI can visualize the proton beam and reveal its range during irradiation of liquid-filled phantoms. A clear dependence on beam energy and current was found. These results stimulate research into novel MRI-detectable beam signatures and already find application in the geometric quality assurance for magnetic resonance-integrated proton therapy systems currently under development.
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Affiliation(s)
- Sebastian Gantz
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Leonhard Karsch
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Jörg Pawelke
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Juliane Peter
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Sonja Schellhammer
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Julien Smeets
- Ion Beam Applications SA, 1348Louvain-la-Neuve, Belgium
| | | | - Aswin Hoffmann
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
- Division of Medical Radiation Physics, Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307Dresden, Germany
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Gayol A, Malano F, Ribo Montenovo C, Pérez P, Valente M. Dosimetry Effects Due to the Presence of Fe Nanoparticles for Potential Combination of Hyperthermic Cancer Treatment with MRI-Based Image-Guided Radiotherapy. Int J Mol Sci 2022; 24:ijms24010514. [PMID: 36613959 PMCID: PMC9820326 DOI: 10.3390/ijms24010514] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/03/2022] [Accepted: 12/06/2022] [Indexed: 12/29/2022] Open
Abstract
Nanoparticles have proven to be biocompatible and suitable for many biomedical applications. Currently, hyperthermia cancer treatments based on Fe nanoparticle infusion excited by alternating magnetic fields are commonly used. In addition to this, MRI-based image-guided radiotherapy represents, nowadays, one of the most promising accurate radiotherapy modalities. Hence, assessing the feasibility of combining both techniques requires preliminary characterization of the corresponding dosimetry effects. The present work reports on a theoretical and numerical simulation feasibility study aimed at pointing out preliminary dosimetry issues. Spatial dose distributions incorporating magnetic nanoparticles in MRI-based image-guided radiotherapy have been obtained by Monte Carlo simulation approaches accounting for all relevant radiation interaction properties as well as charged particles coupling with strong external magnetic fields, which are representative of typical MRI-LINAC devices. Two main effects have been evidenced: local dose enhancement (up to 60% at local level) within the infused volume, and non-negligible changes in the dose distribution at the interfaces between different tissues, developing to over 70% for low-density anatomical cavities. Moreover, cellular uptakes up to 10% have been modeled by means of considering different Fe nanoparticle concentrations. A theoretical temperature-dependent model for the thermal enhancement ratio (TER) has been used to account for radiosensitization due to hyperthermia. The outcomes demonstrated the reliability of the Monte Carlo approach in accounting for strong magnetic fields and mass distributions from patient-specific anatomy CT scans to assess dose distributions in MRI-based image-guided radiotherapy combined with magnetic nanoparticles, while the hyperthermic radiosensitization provides further and synergic contributions.
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Affiliation(s)
- Amiel Gayol
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Francisco Malano
- Centro de Excelencia de Física e Ingeniería en Salud (CFIS), Departamento de Ciencias Físicas, Universidad de La Frontera, Av. Salazar 01145, Casilla 54D, Temuco 4811230, Chile
- Correspondence: (F.M.); (M.V.)
| | - Clara Ribo Montenovo
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Pedro Pérez
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Mauro Valente
- Instituto de Física E. Gaviola (IFEG), CONICET & Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIRx), Facultad de Matemática, Astronomía, Física y Computación (FAMAF), Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
- Centro de Excelencia de Física e Ingeniería en Salud (CFIS), Departamento de Ciencias Físicas, Universidad de La Frontera, Av. Salazar 01145, Casilla 54D, Temuco 4811230, Chile
- Correspondence: (F.M.); (M.V.)
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Wheatley M, De Deene Y. A novel anthropomorphic breathing phantom with a pneumatic MR-safe actuator for tissue deformation studies during MRI and radiotherapy. Phys Med 2022; 104:43-55. [PMID: 36368090 DOI: 10.1016/j.ejmp.2022.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/01/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022] Open
Abstract
A novel MR-safe anthropomorphic torso phantom with an MR-conditional pneumatic respiration system and inflatable lungs for tissue deformation studies is proposed. The phantom consists of a pair of lungs made from sponges encased in flexible polyurethane. The lung phantom also contains a set of silicone tubes of various diameters to mimic the larger vasculature and airways of the lungs. The lungs are surrounded by a plastic ribcage and immersed in a gelatine hydrogel within a flexible polyurethane skin. A plastic pneumatic pump system was constructed to inflate and deflate the lungs. A fibre optic rotary encoder was constructed to determine the volume of displaced air in the lungs. The pneumatic pump and rotary encoder were constructed of plastic materials to allow placement within the bore of the MR scanner with minimal interaction with the magnetic field. Breath-gated scans and rapid imaging scans (2.5 s per image) were taken of the phantom in the stationary state and during inflation/deflation, and with Cartesian and BLADE k-space sampling. It was found that BLADE shows the least motion artifacts during breathing. This phantom and respiration system shows potential for quality assurance of MRI incorporating breathing corrections and for radiotherapy applications in tracking a moving target.
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Affiliation(s)
- Morgan Wheatley
- Faculty of Science and Engineering, Macquarie University, Sydney, Australia.
| | - Yves De Deene
- Faculty of Science and Engineering, Macquarie University, Sydney, Australia; Faculty of Science, Western Sydney University, Sydney, Australia
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De Deene Y. Radiation Dosimetry by Use of Radiosensitive Hydrogels and Polymers: Mechanisms, State-of-the-Art and Perspective from 3D to 4D. Gels 2022; 8:gels8090599. [PMID: 36135311 PMCID: PMC9498652 DOI: 10.3390/gels8090599] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/07/2022] [Accepted: 09/10/2022] [Indexed: 12/22/2022] Open
Abstract
Gel dosimetry was developed in the 1990s in response to a growing need for methods to validate the radiation dose distribution delivered to cancer patients receiving high-precision radiotherapy. Three different classes of gel dosimeters were developed and extensively studied. The first class of gel dosimeters is the Fricke gel dosimeters, which consist of a hydrogel with dissolved ferrous ions that oxidize upon exposure to ionizing radiation. The oxidation results in a change in the nuclear magnetic resonance (NMR) relaxation, which makes it possible to read out Fricke gel dosimeters by use of quantitative magnetic resonance imaging (MRI). The radiation-induced oxidation in Fricke gel dosimeters can also be visualized by adding an indicator such as xylenol orange. The second class of gel dosimeters is the radiochromic gel dosimeters, which also exhibit a color change upon irradiation but do not use a metal ion. These radiochromic gel dosimeters do not demonstrate a significant radiation-induced change in NMR properties. The third class is the polymer gel dosimeters, which contain vinyl monomers that polymerize upon irradiation. Polymer gel dosimeters are predominantly read out by quantitative MRI or X-ray CT. The accuracy of the dosimeters depends on both the physico-chemical properties of the gel dosimeters and on the readout technique. Many different gel formulations have been proposed and discussed in the scientific literature in the last three decades, and scanning methods have been optimized to achieve an acceptable accuracy for clinical dosimetry. More recently, with the introduction of the MR-Linac, which combines an MRI-scanner and a clinical linear accelerator in one, it was shown possible to acquire dose maps during radiation, but new challenges arise.
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Affiliation(s)
- Yves De Deene
- Liverpool & Macarthur Cancer Therapy Centres, Liverpool, NSW 1871, Australia; or
- Ingham Institute, Liverpool, NSW 2170, Australia
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
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10
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Azadeh P, Amiri S, Mostaar A, Yaghobi Joybari A, Paydar R. Evaluation of MAGIC-f polymer gel dosimeter for dose profile measurement in small fields and stereotactic irradiation. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.109991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Patterson E, Oborn BM, Cutajar D, Jelen U, Liney G, Rosenfeld AB, Metcalfe PE. Characterizing magnetically focused contamination electrons by off-axis irradiation on an inline MRI-Linac. J Appl Clin Med Phys 2022; 23:e13591. [PMID: 35333000 PMCID: PMC9195023 DOI: 10.1002/acm2.13591] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/10/2021] [Accepted: 03/02/2022] [Indexed: 11/18/2022] Open
Abstract
Purpose The aim of this study is to investigate off‐axis irradiation on the Australian MRI‐Linac using experiments and Monte Carlo simulations. Simulations are used to verify experimental measurements and to determine the minimum offset distance required to separate electron contamination from the photon field. Methods Dosimetric measurements were performed using a microDiamond detector, Gafchromic® EBT3 film, and MOSkinTM. Three field sizes were investigated including 1.9 × 1.9, 5.8 × 5.8, and 9.7 × 9.6 cm2. Each field was offset a maximum distance, approximately 10 cm, from the central magnetic axis (isocenter). Percentage depth doses (PDDs) were collected at a source‐to‐surface distance (SSD) of 1.8 m for fields collimated centrally and off‐axis. PDD measurements were also acquired at isocenter for each off‐axis field to measure electron contamination. Monte Carlo simulations were used to verify experimental measurements, determine the minimum field offset distance, and demonstrate the use of a spoiler to absorb electron contamination. Results Off‐axis irradiation separates the majority of electron contamination from an x‐ray beam and was found to significantly reduce in‐field surface dose. For the 1.9 × 1.9, 5.8 × 5.8, and 9.7 × 9.6 cm2 field, surface dose was reduced from 120.9% to 24.9%, 229.7% to 39.2%, and 355.3% to 47.3%, respectively. Monte Carlo simulations generally were within experimental error to MOSkinTM and microDiamond, and used to determine the minimum offset distance, 2.1 cm, from the field edge to isocenter. A water spoiler 2 cm thick was shown to reduce electron contamination dose to near zero. Conclusions Experimental and simulation data were acquired for a range of field sizes to investigate off‐axis irradiation on an inline MRI‐Linac. The skin sparing effect was observed with off‐axis irradiation, a feature that cannot be achieved to the same extent with other methods, such as bolusing, for beams at isocenter.
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Affiliation(s)
| | - Bradley M Oborn
- Centre for Medical Radiation Physics, Wollongong, NSW, Australia.,Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, NSW, Australia
| | - Dean Cutajar
- Centre for Medical Radiation Physics, Wollongong, NSW, Australia
| | - Urszula Jelen
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
| | - Gary Liney
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, Wollongong, NSW, Australia.,Illawarra Health Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Peter E Metcalfe
- Centre for Medical Radiation Physics, Wollongong, NSW, Australia.,Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
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12
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Deene YD, Wheatley M, Greig T, Hayes D, Ryder W, Loh H. A multi-modality medical imaging head and neck phantom: Part 1. Design and fabrication. Phys Med 2022; 96:166-178. [DOI: 10.1016/j.ejmp.2022.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 10/19/2022] Open
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13
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Improvement of light stability of DHR123 radio fluorogenic nano clay gel dosimeter by incorporating a new dispersant. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Marrale M, d’Errico F. Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry. Gels 2021; 7:74. [PMID: 34205640 PMCID: PMC8293215 DOI: 10.3390/gels7020074] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 11/28/2022] Open
Abstract
Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30-50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-sensitive gels. The gels are tissue equivalent, so they also serve as phantoms, and their response is largely independent of radiation quality and dose rate. Some of them are infused with ferrous sulfate and rely on the radiation-induced oxidation of ferrous ions to ferric ions (Fricke-gels). Other formulations consist of monomers dispersed in a gelatinous medium (Polyacrylamide gels) and rely on radiation-induced polymerization, which creates a stable polymer structure. In both gel types, irradiation causes changes in proton relaxation rates that are proportional to locally absorbed dose and can be imaged using magnetic resonance imaging (MRI). Changes in color and/or opacification of the gels also occur upon irradiation, allowing the use of optical tomography techniques. In this work, we review both Fricke and polyacrylamide gels with emphasis on their chemical and physical properties and on their applications for radiation dosimetry.
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Affiliation(s)
- Maurizio Marrale
- Department of Physics and Chemistry, “Emilio Segrè” ATeN Center, University of Palermo, 90128 Palermo, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Catania, 95123 Catania, Italy
| | - Francesco d’Errico
- Scuola di Ingegneria, Università degli Studi di Pisa, 56126 Pisa, Italy;
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, 56127 Pisa, Italy
- School of Medicine, Yale University New Haven, CT 06510, USA
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15
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Baldock C, Karger CP, Zaidi H. Gel dosimetry provides the optimal end‐to‐end quality assurance dosimetry for MR‐linacs. Med Phys 2020; 47:3259-3262. [DOI: 10.1002/mp.14239] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 05/09/2020] [Indexed: 01/08/2023] Open
Affiliation(s)
- Clive Baldock
- School of Engineering College of Science and Engineering University of Tasmania TAS Hobart 7005Australia
| | - Christian P. Karger
- Medical Physics in Radiation Oncology German Cancer Research Center (DKFZ), and National Center for Radiation Research in Oncology (NCRO) Heidelberg Institute for Radiation Oncology (HIRO) Im Neuenheimer Feld 280 Heidelberg Germany
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