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Dietrich KA, Klüter S, Dinkel F, Echner G, Brons S, Orzada S, Debus J, Ladd ME, Platt T. An essentially radiation-transparent body coil integrated with a patient rotation system for MR-guided particle therapy. Med Phys 2024; 51:4028-4043. [PMID: 38656549 DOI: 10.1002/mp.17065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 12/28/2023] [Accepted: 03/20/2024] [Indexed: 04/26/2024] Open
Abstract
BACKGROUND The pursuit of adaptive radiotherapy using MR imaging for better precision in patient positioning puts stringent demands on the hardware components of the MR scanner. Particularly in particle therapy, the dose distribution and thus the efficacy of the treatment is susceptible to beam attenuation from interfering materials in the irradiation path. This severely limits the usefulness of conventional imaging coils, which contain highly attenuating parts such as capacitors and preamplifiers in an unknown position, and requires development of a dedicated radiofrequency (RF) coil with close consideration of the materials and components used. PURPOSE In MR-guided radiation therapy in the human torso, imaging coils with a large FOV and homogeneous B1 field distribution are required for reliable tissue classification. In this work, an imaging coil for MR-guided particle therapy was developed with minimal ion attenuation while maintaining flexibility in treatment. METHODS A birdcage coil consisting of nearly radiation-transparent materials was designed and constructed for a closed-bore 1.5 T MR system. Additionally, the coil was mounted on a rotatable patient capsule for flexible positioning of the patient relative to the beam. The ion attenuation of the RF coil was investigated in theory and via measurements of the Bragg peak position. To characterize the imaging quality of the RF coil, transmit and receive field distributions were simulated and measured inside a homogeneous tissue-simulating phantom for various rotation angles of the patient capsule ranging from 0° to 345° in steps of 15°. Furthermore, simulations with a heterogeneous human voxel model were performed to better estimate the effect of real patient loading, and the RF coil was compared to the internal body coil in terms of SNR for a full rotation of the patient capsule. RESULTS The RF coil (total water equivalent thickness (WET) ≈ 420 µm, WET of conductor ≈ 210 µm) can be considered to be radiation-transparent, and a measured transmit power efficiency (B1 +/P $\sqrt {\mathrm{P}} $ ) between 0.17 µT/W $\sqrt {\mathrm{W}} $ and 0.26 µT/W $\sqrt {\mathrm{W}} $ could be achieved in a volume (Δz = 216 mm, complete x and y range) for the 24 investigated rotation angles of the patient capsule. Furthermore, homogeneous transmit and receive field distributions were measured and simulated in the transverse, coronal and sagittal planes in a homogeneous phantom and a human voxel model. In addition, the SNR of the radiation-transparent RF coil varied between 103 and 150, in the volume (Δz = 216 mm) of a homogeneous phantom and surpasses the SNR of the internal body coil for all rotation angles of the patient capsule. CONCLUSIONS A radiation-transparent RF coil was developed and built that enables flexible patient to beam positioning via full rotation capability of the RF coil and patient relative to the beam, with results providing promising potential for adaptive MR-guided particle therapy.
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Affiliation(s)
- Kilian A Dietrich
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics, Heidelberg University, Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Klüter
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
| | - Fabian Dinkel
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Gernot Echner
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Brons
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany
| | - Stephan Orzada
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Faculty of Physics, Heidelberg University, Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Mark E Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics, Heidelberg University, Heidelberg, Germany
- Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Tanja Platt
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Dajani S, Hill VB, Kalapurakal JA, Horbinski CM, Nesbit EG, Sachdev S, Yalamanchili A, Thomas TO. Imaging of GBM in the Age of Molecular Markers and MRI Guided Adaptive Radiation Therapy. J Clin Med 2022; 11:jcm11195961. [PMID: 36233828 PMCID: PMC9572863 DOI: 10.3390/jcm11195961] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 12/03/2022] Open
Abstract
Glioblastoma (GBM) continues to be one of the most lethal malignancies and is almost always fatal. In this review article, the role of radiation therapy, systemic therapy, as well as the molecular basis of classifying GBM is described. Technological advances in the treatment of GBM are outlined as well as the diagnostic imaging characteristics of this tumor. In addition, factors that affect prognosis such as differentiating progression from treatment effect is discussed. The role of MRI guided radiation therapy and how this technology may provide a mechanism to improve the care of patients with this disease are described.
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Buckley JG, Dong B, Liney GP. Imaging performance of a high-field in-line magnetic resonance imaging linear accelerator with a patient rotation system for fixed-gantry radiotherapy. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2020; 16:130-133. [PMID: 33458355 PMCID: PMC7807630 DOI: 10.1016/j.phro.2020.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/05/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023]
Abstract
This paper describes the imaging performance of a high-field in-line MRI linear accelerator with a patient rotation system in-situ. Signal quality was quantified using signal-to-noise ratio (SNR) and RF uniformity maps. B0-field inhomogeneity was assessed using magnetic field mapping. SNR was evaluated with various entries into the Faraday cage which were required for extended couch translations. SNR varied between 103 and 87 across PRS rotation angles. Maximum B0-field inhomogeneity corresponded to 0.7 mm of geometric distortion. A 45 × 55 cm2 aperture allowed PRS translation with no reduction in SNR. Imaging performance with the PRS in-situ was found to be acceptable.
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Affiliation(s)
- Jarryd G Buckley
- Centre for Medical Radiation Physics, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.,Ingham Institute for Applied Medical Research, 1 Campbell St, Liverpool, NSW 2170, Australia
| | - Bin Dong
- Ingham Institute for Applied Medical Research, 1 Campbell St, Liverpool, NSW 2170, Australia.,Liverpool and Macarthur Cancer Therapy Centre, Liverpool Hospital, 75 Elizabeth St, Liverpool, NSW 2170, Australia
| | - Gary P Liney
- Ingham Institute for Applied Medical Research, 1 Campbell St, Liverpool, NSW 2170, Australia.,Liverpool and Macarthur Cancer Therapy Centre, Liverpool Hospital, 75 Elizabeth St, Liverpool, NSW 2170, Australia
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Liney GP, Jelen U, Byrne H, Dong B, Roberts TL, Kuncic Z, Keall P. Technical Note: The first live treatment on a 1.0 Tesla inline
MRI
‐linac. Med Phys 2019; 46:3254-3258. [DOI: 10.1002/mp.13556] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/29/2019] [Accepted: 04/16/2019] [Indexed: 11/06/2022] Open
Affiliation(s)
- Gary P. Liney
- Department of Medical Physics Ingham Institute for Applied Medical Research Liverpool NSW Australia
- Liverpool Cancer Therapy Centre, Radiation Physics Liverpool NSW Australia
- School of Medicine University of New South Wales Sydney NSW Australia
- Centre for Medical Radiation Physics University of Wollongong Wollongong NSW Australia
| | - Urszula Jelen
- Department of Medical Physics Ingham Institute for Applied Medical Research Liverpool NSW Australia
| | - Hilary Byrne
- School of Physics Faculty of Science University of Sydney Sydney NSW Australia
- ACRF ImageX Institute Sydney Medical School University of Sydney Sydney NSW Australia
| | - Bin Dong
- Department of Medical Physics Ingham Institute for Applied Medical Research Liverpool NSW Australia
| | - Tara L. Roberts
- Department of Medical Physics Ingham Institute for Applied Medical Research Liverpool NSW Australia
- School of Medicine Western Sydney University Macarthur NSW Australia
| | - Zdenka Kuncic
- School of Physics Faculty of Science University of Sydney Sydney NSW Australia
- ACRF ImageX Institute Sydney Medical School University of Sydney Sydney NSW Australia
| | - Paul Keall
- ACRF ImageX Institute Sydney Medical School University of Sydney Sydney NSW Australia
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Tijssen RHN, Philippens MEP, Paulson ES, Glitzner M, Chugh B, Wetscherek A, Dubec M, Wang J, van der Heide UA. MRI commissioning of 1.5T MR-linac systems - a multi-institutional study. Radiother Oncol 2018; 132:114-120. [PMID: 30825959 DOI: 10.1016/j.radonc.2018.12.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/14/2018] [Accepted: 12/11/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Magnetic Resonance linear accelerator (MR-linac) systems represent a new type of technology that allows for online MR-guidance for high precision radiotherapy (RT). Currently, the first MR-linac installations are being introduced clinically. Since the imaging performance of these integrated MR-linac systems is critical for their application, a thorough commissioning of the MRI performance is essential. However, guidelines on the commissioning of MR-guided RT systems are not yet defined and data on the performance of MR-linacs are not yet available. MATERIALS & METHODS Here we describe a comprehensive commissioning protocol, which contains standard MRI performance measurements as well as dedicated hybrid tests that specifically assess the interactions between the Linac and the MRI system. The commissioning results of four MR-linac systems are presented in a multi-center study. RESULTS Although the four systems showed similar performance in all the standard MRI performance tests, some differences were observed relating to the hybrid character of the systems. Field homogeneity measurements identified differences in the gantry shim configuration, which was later confirmed by the vendor. CONCLUSION Our results highlight the importance of dedicated hybrid commissioning tests and the ability to compare the machines between institutes at this very early stage of clinical introduction. Until formal guidelines and tolerances are defined the tests described in this study may be used as a practical guideline. Moreover, the multi-center results provide initial bench mark data for future MR-linac installations.
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Affiliation(s)
- Rob H N Tijssen
- Department of Radiotherapy, University Medical Center Utrecht, the Netherlands.
| | | | - Eric S Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, United States
| | - Markus Glitzner
- Department of Radiotherapy, University Medical Center Utrecht, the Netherlands
| | - Brige Chugh
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Andreas Wetscherek
- Joint Department of Physics, the Institute of Cancer Research and the Royal Marsden Hospital NHS Foundation Trust, London, UK
| | - Michael Dubec
- The Christie NHS Foundation Trust and the University of Manchester, UK
| | - Jihong Wang
- Department of Radiation Physics, the University of Texas MD Anderson Cancer Center, Houston, United States
| | - Uulke A van der Heide
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
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Liney G, Whelan B, Oborn B, Barton M, Keall P. MRI-Linear Accelerator Radiotherapy Systems. Clin Oncol (R Coll Radiol) 2018; 30:686-691. [DOI: 10.1016/j.clon.2018.08.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/25/2018] [Accepted: 08/20/2018] [Indexed: 12/25/2022]
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Liney GP, Dong B, Weber E, Rai R, Destruel A, Garcia-Alvarez R, Manton DJ, Jelen U, Zhang K, Barton M, Keall P, Crozier S. Imaging performance of a dedicated radiation transparent RF coil on a 1.0 Tesla inline MRI-linac. ACTA ACUST UNITED AC 2018; 63:135005. [DOI: 10.1088/1361-6560/aac813] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hoogcarspel SJ, Zijlema SE, Tijssen RHN, Kerkmeijer LGW, Jürgenliemk-Schulz IM, Lagendijk JJW, Raaymakers BW. Characterization of the first RF coil dedicated to 1.5 T MR guided radiotherapy. ACTA ACUST UNITED AC 2018; 63:025014. [DOI: 10.1088/1361-6560/aaa303] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Arivarasan I, Anuradha C, Subramanian S, Anantharaman A, Ramasubramanian V. Magnetic resonance image guidance in external beam radiation therapy planning and delivery. Jpn J Radiol 2017; 35:417-426. [DOI: 10.1007/s11604-017-0656-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/29/2017] [Indexed: 12/14/2022]
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Liney GP, Dong B, Begg J, Vial P, Zhang K, Lee F, Walker A, Rai R, Causer T, Alnaghy SJ, Oborn BM, Holloway L, Metcalfe P, Barton M, Crozier S, Keall P. Technical Note: Experimental results from a prototype high-field inline MRI-linac. Med Phys 2017; 43:5188. [PMID: 27587049 DOI: 10.1118/1.4961395] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid magnetic resonance imaging (MRI)-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-linac system. This work describes results from a prototype experimental system to demonstrate the feasibility of a high field inline MR-linac. METHODS The magnet is a 1.5 T MRI system (Sonata, Siemens Healthcare) was located in a purpose built radiofrequency (RF) cage enabling shielding from and close proximity to a linear accelerator with inline (and future perpendicular) orientation. A portable linear accelerator (Linatron, Varian) was installed together with a multileaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-linac experiments was performed to investigate (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array; and (3) electron contamination effects measured using Gafchromic film and an electronic portal imaging device (EPID). RESULTS (1) Image quality was unaffected by the radiation beam with the macropodine phantom image with the beam on being almost identical to the image with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background intensity when the radiation beam was on. (3) Film and EPID measurements demonstrated electron focusing occurring along the centerline of the magnet axis. CONCLUSIONS A proof-of-concept high-field MRI-linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field inline MRI-linac and study a number of the technical challenges and solutions.
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Affiliation(s)
- G P Liney
- Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170, Australia; Radiation Physics, Liverpool Cancer Therapy Centre, Liverpool NSW 2170, Australia; School of Medicine, University of New South Wales, Sydney NSW 2170, Australia; and Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia
| | - B Dong
- Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170, Australia
| | - J Begg
- Radiation Physics, Liverpool Cancer Therapy Centre, Liverpool NSW 2170, Australia
| | - P Vial
- Radiation Physics & Liverpool Cancer Therapy Centre, Liverpool, NSW 2170, Australia and Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - K Zhang
- Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170, Australia
| | - F Lee
- Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - A Walker
- Medical Physics, Ingham Institute for Applied Medical Research, Liverpool, NSW 2170, Australia and Radiation Physics, Liverpool Cancer Therapy Centre, Liverpool NSW 2170, Australia
| | - R Rai
- Medical Physics, Ingham Institute for Applied Medical Research, Liverpool, NSW 2170, Australia and Radiation Physics, Liverpool Cancer Therapy Centre, Liverpool NSW 2170, Australia
| | - T Causer
- Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia
| | - S J Alnaghy
- Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia
| | - B M Oborn
- Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia and Illawarra Cancer Care Centre, Wollongong Hospital, NSW 2500, Australia
| | - L Holloway
- Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170, Australia; Radiation Physics, Liverpool Cancer Therapy Centre, Liverpool NSW 2170, Australia; School of Medicine, University of New South Wales, Sydney NSW 2170, Australia; Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia; and Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - P Metcalfe
- Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia
| | - M Barton
- Department of Medical Physics, Ingham Institute for Applied Medical Research, Liverpool NSW 2170, Australia and School of Medicine, University of New South Wales, Sydney NSW 2170, Australia
| | - S Crozier
- School of Information Technology & Electrical Engineering, University of Queensland, Brisbane, QLD 4072, Australia
| | - P Keall
- Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney NSW 2170, Australia
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Rubinstein AE, Liao Z, Melancon AD, Guindani M, Followill DS, Tailor RC, Hazle JD, Court LE. Technical Note: A Monte Carlo study of magnetic-field-induced radiation dose effects in mice. Med Phys 2016; 42:5510-6. [PMID: 26328998 DOI: 10.1118/1.4928600] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Magnetic fields are known to alter radiation dose deposition. Before patients receive treatment using an MRI-linear accelerator (MRI-Linac), preclinical studies are needed to understand the biological consequences of magnetic-field-induced dose effects. In the present study, the authors sought to identify a beam energy and magnetic field strength combination suitable for preclinical murine experiments. METHODS Magnetic field dose effects were simulated in a mouse lung phantom using various beam energies (225 kVp, 350 kVp, 662 keV [Cs-137], 2 MV, and 1.25 MeV [Co-60]) and magnetic field strengths (0.75, 1.5, and 3 T). The resulting dose distributions were compared with those in a simulated human lung phantom irradiated with a 6 or 8 MV beam and orthogonal 1.5 T magnetic field. RESULTS In the human lung phantom, the authors observed a dose increase of 45% and 54% at the soft-tissue-to-lung interface and a dose decrease of 41% and 48% at the lung-to-soft-tissue interface for the 6 and 8 MV beams, respectively. In the mouse simulations, the magnetic fields had no measurable effect on the 225 or 350 kVp dose distribution. The dose increases with the Cs-137 beam for the 0.75, 1.5, and 3 T magnetic fields were 9%, 29%, and 42%, respectively. The dose decreases were 9%, 21%, and 37%. For the 2 MV beam, the dose increases were 16%, 33%, and 31% and the dose decreases were 9%, 19%, and 30%. For the Co-60 beam, the dose increases were 19%, 54%, and 44%, and the dose decreases were 19%, 42%, and 40%. CONCLUSIONS The magnetic field dose effects in the mouse phantom using a Cs-137, 3 T combination or a Co-60, 1.5 or 3 T combination most closely resemble those in simulated human treatments with a 6 MV, 1.5 T MRI-Linac. The effects with a Co-60, 1.5 T combination most closely resemble those in simulated human treatments with an 8 MV, 1.5 T MRI-Linac.
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Affiliation(s)
- Ashley E Rubinstein
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030
| | - Zhongxing Liao
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Adam D Melancon
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Michele Guindani
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - David S Followill
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Ramesh C Tailor
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - John D Hazle
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Laurence E Court
- Departments of Radiation Physics and Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
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Oborn BM, Dowdell S, Metcalfe PE, Crozier S, Mohan R, Keall PJ. Proton beam deflection in MRI fields: Implications for MRI-guided proton therapy. Med Phys 2015; 42:2113-24. [DOI: 10.1118/1.4916661] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
We have successfully built linac-magnetic resonance imaging (MR) systems based on a linac waveguide placed between open MR planes (perpendicular) or through the central opening of one of the planes (parallel) to improve dosimetric properties. It rotates on a gantry to irradiate at any angle. Irradiation during MR imaging and automatic 2-dimensional MR image-based target tracking and automatic beam steering to the moving target have been demonstrated with our systems. The functioning whole-body system (0.6-T MR and 6-MV linac) has been installed in an existing clinical vault without removing the walls or the ceiling and without the need of a helium exhaust vent.
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Lagendijk JJW, Raaymakers BW, Van den Berg CAT, Moerland MA, Philippens ME, van Vulpen M. MR guidance in radiotherapy. Phys Med Biol 2014; 59:R349-69. [PMID: 25322150 DOI: 10.1088/0031-9155/59/21/r349] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jan J W Lagendijk
- Department of Radiotherapy, University Medical Centre Utrecht, Heidelberglaan 100, Utrecht, The Netherlands
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Bostel T, Nicolay NH, Grossmann JG, Mohr A, Delorme S, Echner G, Häring P, Debus J, Sterzing F. MR-guidance--a clinical study to evaluate a shuttle- based MR-linac connection to provide MR-guided radiotherapy. Radiat Oncol 2014; 9:12. [PMID: 24401489 PMCID: PMC3904210 DOI: 10.1186/1748-717x-9-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/13/2013] [Indexed: 11/10/2022] Open
Abstract
Background The purpose of this clinical study is to investigate the clinical feasibility and safety of a shuttle-based MR-linac connection to provide MR-guided radiotherapy. Methods/Design A total of 40 patients with an indication for a neoadjuvant, adjuvant or definitive radiation treatment will be recruited including tumors of the head and neck region, thorax, upper gastrointestinal tract and pelvic region. All study patients will receive standard therapy, i.e. highly conformal radiation techniques like CT-guided intensity-modulated radiotherapy (IMRT) with or without concomitant chemotherapy or other antitumor medication, and additionally daily short MR scans in treatment position with the same immobilisation equipment used for irradiation for position verification and imaging of the anatomical and functional changes during the course of radiotherapy. For daily position control, skin marks and a stereotactic frame will be used for both imaging modalities. Patient transfer between the MR device and the linear accelerator will be performed with a shuttle system which uses an air-bearing patient platform for both procedures. The daily acquired MR and CT data sets will be digitally registrated, correlated with the planning CT and compared with each other regarding translational and rotational errors. Aim of this clinical study is to establish a shuttle-based approach for realising MR-guided radiotherapy for certain clinical situations. Second objectives are to compare MR-guided radiotherapy with the gold standard of CT image guidance for quality assurance of radiotherapy, to establish an appropiate MR protocol therefore, and to assess the possibility of using MR-based image guidance not only for position verification but also for adaptive strategies in radiotherapy. Discussion Compared to CT, MRI might offer the advantage of providing IGRT without delivering an additional radiation dose to the patients and the possibility of optimisation of adaptive therapy strategies due to its superior soft tissue contrast. However, up to now, hybrid MR-linac devices are still under construction and not clinically applicable. For the near future, a shuttle-based approach would be a promising alternative for providing MR-guided radiotherapy, so that the present study was initiated to determine feasibility and safety of such an approach. Besides positioning information, daily MR data under treatment offer the possibility to assess tumor regression and functional parameters, with a potential impact not only on adaptive therapy strategies but also on early assessment of treatment response.
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Affiliation(s)
- Tilman Bostel
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Hoogcarspel SJ, Crijns SPM, Lagendijk JJW, van Vulpen M, Raaymakers BW. The feasibility of using a conventional flexible RF coil for an online MR-guided radiotherapy treatment. Phys Med Biol 2013; 58:1925-32. [DOI: 10.1088/0031-9155/58/6/1925] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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