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Lee H, Cheon BW, Feld JW, Grogg K, Perl J, Ramos-Méndez JA, Faddegon B, Min CH, Paganetti H, Schuemann J. TOPAS-imaging: extensions to the TOPAS simulation toolkit for medical imaging systems. Phys Med Biol 2023; 68:10.1088/1361-6560/acc565. [PMID: 36930985 PMCID: PMC10164408 DOI: 10.1088/1361-6560/acc565] [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: 11/30/2022] [Accepted: 03/17/2023] [Indexed: 03/19/2023]
Abstract
Objective. The TOol for PArticle Simulation (TOPAS) is a Geant4-based Monte Carlo software application that has been used for both research and clinical studies in medical physics. So far, most users of TOPAS have focused on radiotherapy-related studies, such as modeling radiation therapy delivery systems or patient dose calculation. Here, we present the first set of TOPAS extensions to make it easier for TOPAS users to model medical imaging systems.Approach. We used the extension system of TOPAS to implement pre-built, user-configurable geometry components such as detectors (e.g. flat-panel and multi-planar detectors) for various imaging modalities and pre-built, user-configurable scorers for medical imaging systems (e.g. digitizer chain).Main results. We developed a flexible set of extensions that can be adapted to solve research questions for a variety of imaging modalities. We then utilized these extensions to model specific examples of cone-beam CT (CBCT), positron emission tomography (PET), and prompt gamma (PG) systems. The first of these new geometry components, the FlatImager, was used to model example CBCT and PG systems. Detected signals were accumulated in each detector pixel to obtain the intensity of x-rays penetrating objects or prompt gammas from proton-nuclear interaction. The second of these new geometry components, the RingImager, was used to model an example PET system. Positron-electron annihilation signals were recorded in crystals of the RingImager and coincidences were detected. The simulated data were processed using corresponding post-processing algorithms for each modality and obtained results in good agreement with the expected true signals or experimental measurement.Significance. The newly developed extension is a first step to making it easier for TOPAS users to build and simulate medical imaging systems. Together with existing TOPAS tools, this extension can help integrate medical imaging systems with radiotherapy simulations for image-guided radiotherapy.
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Affiliation(s)
- Hoyeon Lee
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Bo-Wi Cheon
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Gangwon-do 26493, Republic of Korea
| | - Joseph W Feld
- Electrical Engineering and Computer Science Department, Massachusetts Institute of Technology, Cambridge, MA 02139, United States of America
| | - Kira Grogg
- The Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Joseph Perl
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025 United States of America
| | - José A Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115 United States of America
| | - Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115 United States of America
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Gangwon-do 26493, Republic of Korea
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
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Keshmiri S, Brocard S, Serduc R, Adam JF. A high resolution dose calculation engine for x-ray microbeams radiation therapy. Med Phys 2022; 49:3999-4017. [PMID: 35342953 PMCID: PMC9322281 DOI: 10.1002/mp.15637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Microbeam radiation therapy (MRT) is a treatment modality based on spatial fractionation of synchrotron generated x-rays into parallel, high dose, microbeams of a few microns width. MRT is still an under-development radiosurgery technique for which, promising preclinical results on brain tumors and epilepsy encourages its clinical transfer. PURPOSE A safe clinical transfer of MRT needs a specific treatment planning system (TPS) that provides accurate dose calculations in human patients, taking into account the MRT beams properties (high dose gradients, spatial fractionation, polarization effects). So far, the most advanced MRT treatment planning system, based on a hybrid dose calculation algorithm, is limited to a macroscopic rendering of the dose and does not account for the complex dose distribution inherent to MRT if delivered as conformal irradiations with multiple incidences. For overcoming these limitations, a multi-scale full Monte-Carlo calculation engine called penMRT has been developed and benchmarked against two general purpose Monte Carlo codes: penmain based on PENELOPE and Gate based on Geant4. METHODS PenMRT, is based on the PENELOPE (2018) Monte Carlo (MC) code, modified to take into account the voxelized geometry of the patients (CT-scans) and offering an adaptive micrometric dose calculation grid independent to the CT size, location and orientation. The implementation of the dynamic memory allocation in penMRT, makes the simulations feasible within a huge number of dose scoring bins. The possibility of using a source replication approach to simulate arrays of microbeams, and the parallelization using OpenMPI have been added to penMRT in order to increase the calculation speed for clinical usages. This engine can be implemented in a TPS as a dose calculation core. RESULTS The performance tests highlight the reliability of penMRT to be used for complex irradiation conditions in MRT. The benchmarking against a standard PENELOPE code did not show any significant difference for calculations in centimetric beams, for a single microbeam and for a microbeam array. The comparisons between penMRT and Gate as an independent MC code did not show any difference in the beam paths, whereas in valley regions, relative differences between the two codes rank from 1 to 7.5% which are probably due to the differences in physics lists that are used in these two codes. The reliability of the source replication approach has also been tested and validated with an underestimation of no more than 0.6% in low dose areas. CONCLUSIONS Good agreements (a relative difference between 0 to 8%) were found when comparing calculated peak to valley dose ratio (PVDR) values using penMRT, for irradiations with a full microbeam array, with calculated values in the literature. The high-resolution calculated dose maps obtained with penMRT are used to extract differential and cumulative dose-volume histograms (DVHs) and analyze treatment plans with much finer metrics regarding the irradiation complexity. To our knowledge, these are the first high-resolution dose maps and associated DVHs ever obtained for cross-fired microbeams irradiation, which is bringing a significant added value to the field of treatment planning in spatially fractionated radiation therapy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | - Sylvan Brocard
- Univ. Grenoble Alpes, INSERM, UA07 STROBE, Grenoble, 38000, France
| | - Raphaël Serduc
- Univ. Grenoble Alpes, INSERM, UA07 STROBE, Grenoble, 38000, France.,Centre Hospitalier Universitaire de Grenoble, Grenoble, 38000, France
| | - Jean-François Adam
- Univ. Grenoble Alpes, INSERM, UA07 STROBE, Grenoble, 38000, France.,Centre Hospitalier Universitaire de Grenoble, Grenoble, 38000, France
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Laissue JA. Elke Bräuer-Krisch: dedication, creativity and generosity: May 17, 1961-September 10, 2018. Int J Radiat Biol 2021; 98:280-287. [PMID: 34129423 DOI: 10.1080/09553002.2021.1941385] [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] [Indexed: 10/21/2022]
Abstract
PURPOSE This extraordinary woman worked her professional way from a radiation protection engineer to become the successful principal investigator of a prestigious international European project for a new radiation therapy (ERC Synergy grant, HORIZON 2020). The evaluation of the submitted proposal was very positive. The panel proposed that it be funded. Elke tragically passed away a few days before this conclusion of the panel. The present account describes her gradual career development; it includes many episodes that Elke personally chronicled in her curriculum of 2017. METHODS An internet literature search was performed using Google Scholar and other sources to assist in the writing of this narrative review and account. CONCLUSIONS In parallel to the development of the new Biomedical Beamline ID17 at the European Synchrotron Radiation Facility in Grenoble in the late nineties, Elke focused her interest and her personal and professional priorities on MRT, particularly on its clinical goals. She outlined her main objectives in several documents: (1) develop a new paradigm of cancer care by broadening the foundation for MRT. (2) Filling the gaps in basic biological knowledge about the mechanisms of MRT effects on normal and neoplastic tissues. (3) Broaden the preclinical level of evidence for the low normal organ toxicity of MRT versus standard X-ray irradiations; preclinical experiments involved the application of MRT to animal tumor patients, to animals of larger size than laboratory rodents, using larger radiation field sizes, and irradiating in a real-time scenario comparable to the one planned for human patients. (4) To foster the specific purpose of radiosurgical MRT of tumor patients at the ESRF that required development of new, specific state of the art modalities and tools for treatment planning, dosimetry, dose calculation, patient positioning and, of particular importance, redundant levels of patient safety. Just as she was about to take responsibility as principal investigator for a prestigious international European project on a new radiation therapy, death called Elke in.
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Affiliation(s)
- Jean A Laissue
- Institute of Pathology, University of Bern, Bern, Switzerland
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4
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Clinical microbeam radiation therapy with a compact source: specifications of the line-focus X-ray tube. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2021; 14:74-81. [PMID: 33458318 PMCID: PMC7807643 DOI: 10.1016/j.phro.2020.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/20/2020] [Accepted: 05/29/2020] [Indexed: 02/02/2023]
Abstract
Line-focus X-ray tubes are suitable for clinical microbeam radiation therapy (MRT). A modular high-voltage supply safely enables high electron beam powers. An electron accelerator was designed to generate an eccentric focal spot. We simulated a peak-to-valley dose ratio above 20 for single-field MRT. Microbeam arc therapy spares healthy brain tissue compared to single-field MRT.
Background and purpose Microbeam radiotherapy (MRT) is a preclinical concept in radiation oncology with arrays of alternating micrometer-wide high-dose peaks and low-dose valleys. Experiments demonstrated a superior normal tissue sparing at similar tumor control rates with MRT compared to conventional radiotherapy. Possible clinical applications are currently limited to large third-generation synchrotrons. Here, we investigated the line-focus X-ray tube as an alternative microbeam source. Materials and methods We developed a concept for a high-voltage supply and an electron source. In Monte Carlo simulations, we assessed the influence of X-ray spectrum, focal spot size, electron incidence angle, and photon emission angle on the microbeam dose distribution. We further assessed the dose distribution of microbeam arc therapy and suggested to interpret this complex dose distribution by equivalent uniform dose. Results An adapted modular multi-level converter can supply high-voltage powers in the megawatt range for a few seconds. The electron source with a thermionic cathode and a quadrupole can generate an eccentric, high-power electron beam of several 100 keV energy. Highest dose rates and peak-to-valley dose ratios (PVDRs) were achieved for an electron beam impinging perpendicular onto the target surface and a focal spot smaller than the microbeam cross-section. The line-focus X-ray tube simulations demonstrated PVDRs above 20. Conclusion The line-focus X-ray tube is a suitable compact source for clinical MRT. We demonstrated its technical feasibility based on state-of-the-art high-voltage and electron-beam technology. Microbeam arc therapy is an effective concept to increase the target-to-entrance dose ratio of orthovoltage microbeams.
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Zabihzadeh M, Rabiei A, Shahbazian H, Razmjoo S. Investigating the Dosimetric Characteristics of Microbeam Radiation Treatment. JOURNAL OF MEDICAL SIGNALS & SENSORS 2021; 11:45-51. [PMID: 34026590 PMCID: PMC8043115 DOI: 10.4103/jmss.jmss_12_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 07/05/2020] [Accepted: 07/11/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND High-radiation therapeutic gain could be achieved by the modern technique of microbeam radiation treatment (MRT). The aim of this study was to investigate the dosimetric properties of MRT. METHODS The EGSnrc Monte Carlo (MC) code system was used to transport photons and electrons in MRT. The mono-energetic beams (1 cm × 1 cm array) of 50, 100, and 150 keV and the spectrum photon beam (European Synchrotron Radiation Facility [ESRF]) were modeled to transport through multislit collimators with the aperture's widths of 25 and 50 μm and the center-to-center (c-t-c) distance between two adjacent microbeams (MBs) of 200 μm. The calculated phase spaces at the upper surface of water phantom (1 cm × 1 cm) were implemented in DOSXYZnrc code to calculate the percentage depth dose (PDD), the dose profile curves (in depths of 0-1, 1-2, and 3-4 cm), and the peak-to-valley dose ratios (PVDRs). RESULTS The PDD, dose profile curves, and PVDRs were calculated for different effective parameters. The more flatness of lateral dose profile was obtained for the ESRF spectrum MB. With constant c-t-c distance, an increase in the MB size increased the peak and valley dose; simultaneously, the PVDR was larger for the 25 μm MB (33.5) compared to 50 μm MB (21.9) beam, due to the decreased scattering photons followed to the lower overlapping of the adjacent MBs. An increase in the depth decreased the PVDRs (i.e., 54.9 in depth of 0-1 cm). CONCLUSION Our MC model of MRT successfully calculated the effect of dosimetric parameters including photon's energy, beam width, and depth to estimate the dose distribution.
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Affiliation(s)
- Mansour Zabihzadeh
- Cancer Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Department of Clinical Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Atefeh Rabiei
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Hojattollah Shahbazian
- Department of Clinical Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Sasan Razmjoo
- Department of Clinical Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Day LRJ, Pellicioli P, Gagliardi F, Barnes M, Smyth LML, Butler D, Livingstone J, Stevenson AW, Lye J, Poole CM, Hausermann D, Rogers PAW, Crosbie JC. A Monte Carlo model of synchrotron radiotherapy shows good agreement with experimental dosimetry measurements: Data from the imaging and medical beamline at the Australian Synchrotron. Phys Med 2020; 77:64-74. [PMID: 32791426 DOI: 10.1016/j.ejmp.2020.07.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 06/22/2020] [Accepted: 07/13/2020] [Indexed: 02/06/2023] Open
Abstract
Experimental measurement of Synchrotron Radiotherapy (SyncRT) doses is challenging, especially for Microbeam Radiotherapy (MRT), which is characterised by very high dynamic ranges with spatial resolutions on the micrometer scale. Monte Carlo (MC) simulation is considered a gold standard for accurate dose calculation in radiotherapy, and is therefore routinely relied upon to produce verification data. We present a MC model for Australian Synchrotron's Imaging and Medical Beamline (IMBL), which is capable of generating accurate dosimetry data to inform and/or verify SyncRT experiments. Our MC model showed excellent agreement with dosimetric measurement for Synchrotron Broadbeam Radiotherapy (SBBR). Our MC model is also the first to achieve validation for MRT, using two methods of dosimetry, to within clinical tolerances of 5% for a 20×20 mm2 field size, except for surface measurements at 5 mm depth, which remained to within good agreement of 7.5%. Our experimental methodology has allowed us to control measurement uncertainties for MRT doses to within 5-6%, which has also not been previously achieved, and provides a confidence which until now has been lacking in MRT validation studies. The MC model is suitable for SyncRT dose calculation of clinically relevant field sizes at the IMBL, and can be extended to include medical beamlines at other Synchrotron facilities as well. The presented MC model will be used as a validation tool for treatment planning dose calculation algorithms, and is an important step towards veterinary SyncRT trials at the Australian Synchrotron.
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Affiliation(s)
- L R J Day
- School of Science, RMIT University, Melbourne, Australia.
| | - P Pellicioli
- The European Synchrotron Radiation Facility, ID17 Biomedical Beamline, Grenoble, France; Inserm UA7 STROBE, Grenoble Alps University, Grenoble, France; Swansea University Medical School, Singleton Park, Swansea, United Kingdom
| | - F Gagliardi
- Radiation Oncology, Alfred Hospital, Melbourne, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
| | - M Barnes
- Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia; Australian Nuclear Science and Technology Organisation (ANSTO), Australian Synchrotron, Clayton, Australia
| | - L M L Smyth
- Department of Obstetrics and Gynaecology, University of Melbourne, Royal Women's Hospital, Melbourne, Australia
| | - D Butler
- Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Melbourne, Australia
| | - J Livingstone
- Australian Nuclear Science and Technology Organisation (ANSTO), Australian Synchrotron, Clayton, Australia
| | - A W Stevenson
- Australian Nuclear Science and Technology Organisation (ANSTO), Australian Synchrotron, Clayton, Australia
| | - J Lye
- Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Melbourne, Australia
| | - C M Poole
- Radiation Analytics, Brisbane, Australia
| | - D Hausermann
- Australian Nuclear Science and Technology Organisation (ANSTO), Australian Synchrotron, Clayton, Australia
| | - P A W Rogers
- Department of Obstetrics and Gynaecology, University of Melbourne, Royal Women's Hospital, Melbourne, Australia
| | - J C Crosbie
- School of Science, RMIT University, Melbourne, Australia
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Bartzsch S, Corde S, Crosbie JC, Day L, Donzelli M, Krisch M, Lerch M, Pellicioli P, Smyth LML, Tehei M. Technical advances in x-ray microbeam radiation therapy. Phys Med Biol 2020; 65:02TR01. [PMID: 31694009 DOI: 10.1088/1361-6560/ab5507] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In the last 25 years microbeam radiation therapy (MRT) has emerged as a promising alternative to conventional radiation therapy at large, third generation synchrotrons. In MRT, a multi-slit collimator modulates a kilovoltage x-ray beam on a micrometer scale, creating peak dose areas with unconventionally high doses of several hundred Grays separated by low dose valley regions, where the dose remains well below the tissue tolerance level. Pre-clinical evidence demonstrates that such beam geometries lead to substantially reduced damage to normal tissue at equal tumour control rates and hence drastically increase the therapeutic window. Although the mechanisms behind MRT are still to be elucidated, previous studies indicate that immune response, tumour microenvironment, and the microvasculature may play a crucial role. Beyond tumour therapy, MRT has also been suggested as a microsurgical tool in neurological disorders and as a primer for drug delivery. The physical properties of MRT demand innovative medical physics and engineering solutions for safe treatment delivery. This article reviews technical developments in MRT and discusses existing solutions for dosimetric validation, reliable treatment planning and safety. Instrumentation at synchrotron facilities, including beam production, collimators and patient positioning systems, is also discussed. Specific solutions reviewed in this article include: dosimetry techniques that can cope with high spatial resolution, low photon energies and extremely high dose rates of up to 15 000 Gy s-1, dose calculation algorithms-apart from pure Monte Carlo Simulations-to overcome the challenge of small voxel sizes and a wide dynamic dose-range, and the use of dose-enhancing nanoparticles to combat the limited penetrability of a kilovoltage energy spectrum. Finally, concepts for alternative compact microbeam sources are presented, such as inverse Compton scattering set-ups and carbon nanotube x-ray tubes, that may facilitate the transfer of MRT into a hospital-based clinical environment. Intensive research in recent years has resulted in practical solutions to most of the technical challenges in MRT. Treatment planning, dosimetry and patient safety systems at synchrotrons have matured to a point that first veterinary and clinical studies in MRT are within reach. Should these studies confirm the promising results of pre-clinical studies, the authors are confident that MRT will become an effective new radiotherapy option for certain patients.
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Affiliation(s)
- Stefan Bartzsch
- Department of Radiation Oncology, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany. Helmholtz Centre Munich, Institute for Radiation Medicine, Munich, Germany
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Kandlakunta P, Momin S, Sloop A, Zhang T, Khan R. Characterizing a Geant4 Monte Carlo model of a multileaf collimator for a TrueBeam™ linear accelerator. Phys Med 2019; 59:1-12. [PMID: 30928056 DOI: 10.1016/j.ejmp.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The purpose of this work was to develop and validate a multileaf collimator (MLC) model for a TrueBeam™ linac using Geant4 Monte Carlo (MC) simulation kit. METHODS A Geant4 application was developed to accurately represent TrueBeam™ linac. Pre-computed phase-space file in a plane just above the jaws was used for radiation transport. A Varian 120 leaf Millennium™ MLC was modeled using geometry and material specifications provided by the manufacturer using Geant4 constructs. Leaf characteristics e.g. tongue-groove design, variable thickness, interleaf gap were simulated. The linac model was validated by comparing simulated dose profiles and depth-doses with experimental data using an ionization chamber in water. Dosimetric characteristics of the MLC such as inter- and intra-leaf leakage, penumbra effect, MLC leaf positioning, and dynamic characteristics were also investigated. RESULTS For the depth dose curves, 99% of the calculated data points agree within 1% of the experimental values for the 4 × 4 cm2 and 10 × 10 cm2 and within 2% of the experimental values for 20 × 20, 30 × 30 and 40 × 40 cm2 jaw defined fields. The cross-plane dose profiles show agreement <2% for depths up to 10 cm and to within 4% beyond 10 cm. MLC dosimetric characterization with MC agree well with film measurements. The rounded leaf penumbra remained constant throughout the range of leaf motion. CONCLUSIONS The TrueBeam™ linac equipped with 120-leaf MLC was successfully modeled using Geant4. The accuracy of the model was verified by comparing the simulations with experiments. The model may be utilized for independent dose verification and QA of IMRT.
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Affiliation(s)
- Praneeth Kandlakunta
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Shadab Momin
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Austin Sloop
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Tiezhi Zhang
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Rao Khan
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA.
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Donzelli M, Oelfke U, Bräuer-Krisch E. Introducing the concept of spiral microbeam radiation therapy (spiralMRT). Phys Med Biol 2019; 64:065005. [PMID: 30650386 DOI: 10.1088/1361-6560/aaff23] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
MOTIVATION With interlaced microbeam radiation therapy (MRT) a first kilovoltage radiotherapy (RT) concept combining spatially fractionated entrance beams and homogeneous dose distribution at the target exists. However, this technique suffers from its high sensitivity to positioning errors of the target relative to the radiation source. With spiral microbeam radiation therapy (spiralMRT), this publication introduces a new irradiation geometry, offering similar spatial fractionation properties as interlaced MRT, while being less vulnerable to target positioning uncertainties. METHODS The dose distributions achievable with spiralMRT in a simplified human head geometry were calculated with Monte Carlo simulations based on Geant4 and the dependence of the result on the microbeam pitch, total field size, and photon energy were analysed. A comparison with interlaced MRT and conventional megavoltage tomotherapy was carried out. RESULTS SpiralMRT can deliver homogeneous dose distributions, while using spatially fractionated entrance beams. The valley dose of spiralMRT entrance beams is by up to 40% lower than the corresponding tomotherapy dose, thus indicating a better normal tissue sparing. The optimum photon energy is found to be around [Formula: see text]. CONCLUSIONS SpiralMRT is a promising approach to delivering homogeneous dose distributions with spatially fractionated entrance beams, possibly decreasing normal tissue side effects in hypofractionated RT.
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Affiliation(s)
- Mattia Donzelli
- European Synchrotron Radiation Facility, Biomedical beamline ID17, Grenoble, France. Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom. Author to whom any correspondence should be addressed
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Slimani FAA, Hamdi M, Bentourkia M. G4DARI: Geant4/GATE based Monte Carlo simulation interface for dosimetry calculation in radiotherapy. Comput Med Imaging Graph 2018; 67:30-39. [PMID: 29738914 DOI: 10.1016/j.compmedimag.2018.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/15/2018] [Accepted: 04/24/2018] [Indexed: 11/17/2022]
Abstract
Monte Carlo (MC) simulation is widely recognized as an important technique to study the physics of particle interactions in nuclear medicine and radiation therapy. There are different codes dedicated to dosimetry applications and widely used today in research or in clinical application, such as MCNP, EGSnrc and Geant4. However, such codes made the physics easier but the programming remains a tedious task even for physicists familiar with computer programming. In this paper we report the development of a new interface GEANT4 Dose And Radiation Interactions (G4DARI) based on GEANT4 for absorbed dose calculation and for particle tracking in humans, small animals and complex phantoms. The calculation of the absorbed dose is performed based on 3D CT human or animal images in DICOM format, from images of phantoms or from solid volumes which can be made from any pure or composite material to be specified by its molecular formula. G4DARI offers menus to the user and tabs to be filled with values or chemical formulas. The interface is described and as application, we show results obtained in a lung tumor in a digital mouse irradiated with seven energy beams, and in a patient with glioblastoma irradiated with five photon beams. In conclusion, G4DARI can be easily used by any researcher without the need to be familiar with computer programming, and it will be freely available as an application package.
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Affiliation(s)
- Faiçal A A Slimani
- Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada
| | - Mahdjoub Hamdi
- Département de Génie Électrique, Université de Mostaganem, Algeria
| | - M'hamed Bentourkia
- Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada.
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Donzelli M, Bräuer-Krisch E, Oelfke U, Wilkens JJ, Bartzsch S. Hybrid dose calculation: a dose calculation algorithm for microbeam radiation therapy. Phys Med Biol 2018; 63:045013. [PMID: 29324439 PMCID: PMC5964549 DOI: 10.1088/1361-6560/aaa705] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 12/07/2017] [Accepted: 01/11/2018] [Indexed: 12/17/2022]
Abstract
Microbeam radiation therapy (MRT) is still a preclinical approach in radiation oncology that uses planar micrometre wide beamlets with extremely high peak doses, separated by a few hundred micrometre wide low dose regions. Abundant preclinical evidence demonstrates that MRT spares normal tissue more effectively than conventional radiation therapy, at equivalent tumour control. In order to launch first clinical trials, accurate and efficient dose calculation methods are an inevitable prerequisite. In this work a hybrid dose calculation approach is presented that is based on a combination of Monte Carlo and kernel based dose calculation. In various examples the performance of the algorithm is compared to purely Monte Carlo and purely kernel based dose calculations. The accuracy of the developed algorithm is comparable to conventional pure Monte Carlo calculations. In particular for inhomogeneous materials the hybrid dose calculation algorithm out-performs purely convolution based dose calculation approaches. It is demonstrated that the hybrid algorithm can efficiently calculate even complicated pencil beam and cross firing beam geometries. The required calculation times are substantially lower than for pure Monte Carlo calculations.
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Affiliation(s)
- Mattia Donzelli
- The European
Synchrotron Radiation Facility, 71 Avenue des Martyrs 38000,
Grenoble, France
- The Institute of
Cancer Research, 15 Cotswold Road, Sutton, London SM2 5NG,
United Kingdom
- Author to whom any correspondence should be
addressed
| | - Elke Bräuer-Krisch
- The European
Synchrotron Radiation Facility, 71 Avenue des Martyrs 38000,
Grenoble, France
| | - Uwe Oelfke
- The Institute of
Cancer Research, 15 Cotswold Road, Sutton, London SM2 5NG,
United Kingdom
| | - Jan J Wilkens
- Department of Radiation Oncology, Klinikum rechts
der Isar, Technical University of
Munich, Ismaninger Straße 22, 81675 Munich,
Germany
| | - Stefan Bartzsch
- The Institute of
Cancer Research, 15 Cotswold Road, Sutton, London SM2 5NG,
United Kingdom
- Department of Radiation Oncology, Klinikum rechts
der Isar, Technical University of
Munich, Ismaninger Straße 22, 81675 Munich,
Germany
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12
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Livingstone J, Stevenson AW, Häusermann D, Adam JF. Experimental optimisation of the X-ray energy in microbeam radiation therapy. Phys Med 2017; 45:156-161. [PMID: 29472081 DOI: 10.1016/j.ejmp.2017.12.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/18/2017] [Accepted: 12/23/2017] [Indexed: 11/30/2022] Open
Abstract
Microbeam radiation therapy has demonstrated superior normal tissue sparing properties compared to broadbeam radiation fields. The ratio of the microbeam peak dose to the valley dose (PVDR), which is dependent on the X-ray energy/spectrum and geometry, should be maximised for an optimal therapeutic ratio. Simulation studies in the literature report the optimal energy for MRT based on the PVDR. However, most of these studies have considered different microbeam geometries to that at the Imaging and Medical Beamline (50 μm beam width with a spacing of 400 μm). We present the first fully experimental investigation of the energy dependence of PVDR and microbeam penumbra. Using monochromatic X-ray energies in the range 40-120 keV the PVDR was shown to increase with increasing energy up to 100 keV before plateauing. PVDRs measured for pink beams were consistently higher than those for monochromatic energies similar or equivalent to the average energy of the spectrum. The highest PVDR was found for a pink beam average energy of 124 keV. Conversely, the microbeam penumbra decreased with increasing energy before plateauing for energies above 90 keV. The effect of bone on the PVDR was investigated at energies 60, 95 and 120 keV. At depths greater than 20 mm beyond the bone/water interface there was almost no effect on the PVDR. In conclusion, the optimal energy range for MRT at IMBL is 90-120 keV, however when considering the IMBL flux at different energies, a spectrum with 95 keV weighted average energy was found to be the best compromise.
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Affiliation(s)
- Jayde Livingstone
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, Victoria, Australia.
| | - Andrew W Stevenson
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, Victoria, Australia
| | - Daniel Häusermann
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, Victoria, Australia
| | - Jean-François Adam
- Equipe d'accueil Rayonnement Synchrotron et Recherche Médicale, Université Grenoble-Alpes, Grenoble, France; Centre Hospitalier Universitaire de Grenoble, Grenoble, France
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13
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Lin H, Jing J, Xu L, Mao X. Monte Carlo study of the influence of energy spectra, mesh size, high Z element on dose and PVDR based on 1-D and 3-D heterogeneous mouse head phantom for Microbeam Radiation Therapy. Phys Med 2017; 44:96-107. [DOI: 10.1016/j.ejmp.2017.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 12/01/2022] Open
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14
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Guardiola C, Peucelle C, Prezado Y. Optimization of the mechanical collimation for minibeam generation in proton minibeam radiation therapy. Med Phys 2017; 44:1470-1478. [DOI: 10.1002/mp.12131] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 01/17/2017] [Accepted: 01/17/2017] [Indexed: 11/11/2022] Open
Affiliation(s)
- Consuelo Guardiola
- IMNC-UMR 8165; CNRS; Paris 7 and Paris 11 Universities; 15 rue Georges Clemenceau Orsay Cedex 91405 France
| | - Cécile Peucelle
- IMNC-UMR 8165; CNRS; Paris 7 and Paris 11 Universities; 15 rue Georges Clemenceau Orsay Cedex 91405 France
| | - Yolanda Prezado
- IMNC-UMR 8165; CNRS; Paris 7 and Paris 11 Universities; 15 rue Georges Clemenceau Orsay Cedex 91405 France
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15
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Fernandez-Palomo C, Mothersill C, Bräuer-Krisch E, Laissue J, Seymour C, Schültke E. γ-H2AX as a marker for dose deposition in the brain of wistar rats after synchrotron microbeam radiation. PLoS One 2015; 10:e0119924. [PMID: 25799425 PMCID: PMC4370487 DOI: 10.1371/journal.pone.0119924] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 01/17/2015] [Indexed: 01/01/2023] Open
Abstract
Objective Synchrotron radiation has shown high therapeutic potential in small animal models of malignant brain tumours. However, more studies are needed to understand the radiobiological effects caused by the delivery of high doses of spatially fractionated x-rays in tissue. The purpose of this study was to explore the use of the γ-H2AX antibody as a marker for dose deposition in the brain of rats after synchrotron microbeam radiation therapy (MRT). Methods Normal and tumour-bearing Wistar rats were exposed to 35, 70 or 350 Gy of MRT to their right cerebral hemisphere. The brains were extracted either at 4 or 8 hours after irradiation and immediately placed in formalin. Sections of paraffin-embedded tissue were incubated with anti γ-H2AX primary antibody. Results While the presence of the C6 glioma does not seem to modulate the formation of γ-H2AX in normal tissue, the irradiation dose and the recovery versus time are the most important factors affecting the development of γ-H2AX foci. Our results also suggest that doses of 350 Gy can trigger the release of bystander signals that significantly amplify the DNA damage caused by radiation and that the γ-H2AX biomarker does not only represent DNA damage produced by radiation, but also damage caused by bystander effects. Conclusion In conclusion, we suggest that the γ-H2AX foci should be used as biomarker for targeted and non-targeted DNA damage after synchrotron radiation rather than a tool to measure the actual physical doses.
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Affiliation(s)
- Cristian Fernandez-Palomo
- Stereotactic Neurosurgery and Laboratory for Molecular Neurosurgery, Freiburg University Medical Center, Freiburg, Germany
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
| | - Carmel Mothersill
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, Canada
| | | | - Jean Laissue
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Colin Seymour
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, Canada
| | - Elisabeth Schültke
- Stereotactic Neurosurgery and Laboratory for Molecular Neurosurgery, Freiburg University Medical Center, Freiburg, Germany
- Department of Radiotherapy/Laboratory of Radiobiology, Rostock University Medical Center, Rostock, Germany
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16
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Anderson DL, Mirzayans R, Andrais B, Siegbahn EA, Fallone BG, Warkentin B. Spatial and temporal distribution of γH2AX fluorescence in human cell cultures following synchrotron-generated X-ray microbeams: lack of correlation between persistent γH2AX foci and apoptosis. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:801-810. [PMID: 24971978 DOI: 10.1107/s1600577514011424] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/17/2014] [Indexed: 06/03/2023]
Abstract
Formation of γH2AX foci (a marker of DNA double-strand breaks), rates of foci clearance and apoptosis were investigated in cultured normal human fibroblasts and p53 wild-type malignant glioma cells after exposure to high-dose synchrotron-generated microbeams. Doses up to 283 Gy were delivered using beam geometries that included a microbeam array (50 µm wide, 400 µm spacing), single microbeams (60-570 µm wide) and a broad beam (32 mm wide). The two cell types exhibited similar trends with respect to the initial formation and time-dependent clearance of γH2AX foci after irradiation. High levels of γH2AX foci persisted as late as 72 h post-irradiation in the majority of cells within cultures of both cell types. Levels of persistent foci after irradiation via the 570 µm microbeam or broad beam were higher when compared with those observed after exposure to the 60 µm microbeam or microbeam array. Despite persistence of γH2AX foci, these irradiation conditions triggered apoptosis in only a small proportion (<5%) of cells within cultures of both cell types. These results contribute to the understanding of the fundamental biological consequences of high-dose microbeam irradiations, and implicate the importance of non-apoptotic responses such as p53-mediated growth arrest (premature senescence).
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Affiliation(s)
- Danielle L Anderson
- Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada
| | - Razmik Mirzayans
- Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada
| | - Bonnie Andrais
- Experimental Oncology, Cross Cancer Institute, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada
| | - E Albert Siegbahn
- Medical Physics, Stockholm University, Box 260, S-17176 Stockholm, Sweden
| | - B Gino Fallone
- Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada
| | - Brad Warkentin
- Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada
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Cornelius I, Guatelli S, Fournier P, Crosbie JC, Sanchez Del Rio M, Bräuer-Krisch E, Rosenfeld A, Lerch M. Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:518-528. [PMID: 24763641 DOI: 10.1107/s1600577514004640] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 02/28/2014] [Indexed: 06/03/2023]
Abstract
Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including recent modifications, using the Geant4 Monte Carlo toolkit interfaced with the SHADOW X-ray optics and ray-tracing libraries. The code was benchmarked by simulating dose profiles in water-equivalent phantoms subject to irradiation by broad-beam (without spatial fractionation) and microbeam (with spatial fractionation) fields, and comparing against those calculated with a previous model of the beamline developed using the PENELOPE code. Validation against additional experimental dose profiles in water-equivalent phantoms subject to broad-beam irradiation was also performed. Good agreement between codes was observed, with the exception of out-of-field doses and toward the field edge for larger field sizes. Microbeam results showed good agreement between both codes and experimental results within uncertainties. Results of the experimental validation showed agreement for different beamline configurations. The asymmetry in the out-of-field dose profiles due to polarization effects was also investigated, yielding important information for the treatment planning process in MRT. This work represents an important step in the development of a Monte Carlo-based independent verification tool for treatment planning in MRT.
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Affiliation(s)
- Iwan Cornelius
- Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Australia
| | - Pauline Fournier
- Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Australia
| | - Jeffrey C Crosbie
- Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, Victoria 3152, Australia
| | | | | | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Australia
| | - Michael Lerch
- Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Australia
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18
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Bartzsch S, Lerch M, Petasecca M, Bräuer-Krisch E, Oelfke U. Influence of polarization and a source model for dose calculation in MRT. Med Phys 2014; 41:041703. [DOI: 10.1118/1.4867858] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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19
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Abstract
PURPOSE This Monte Carlo simulation work aims at studying a new radiotherapy approach called proton-minibeam radiation therapy (pMBRT). The main objective of this proof of concept was the evaluation of the possible gain in tissue sparing, thanks to the spatial fractionation of the dose, which could be used to deposit higher and potentially curative doses in clinical cases where tissue tolerances are a limit for conventional methods. METHODS Monte Carlo simulations (GATE v.6) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) for arrays of proton minibeams of 0.7 mm width and several center-to-center distances, at different depths in a water phantom. The beam penumbras were also evaluated as an important parameter for tissue sparing, for example, in the treatment of non-cancer diseases like epilepsy. Two proton energies were considered in this study: a clinically relevant energy (105 MeV) and a very high energy (1 GeV), to benefit from a reduced lateral scattering. For the latter case, an interlaced geometry was also evaluated. RESULTS Higher or similar PVDR than the ones obtained in x-rays minibeam radiation therapy were achieved in several pMBRT configurations. In addition, for the two energies studied, the beam penumbras are smaller than in the case of Gamma Knife radiosurgery. CONCLUSIONS The high PVDR obtained for some configurations and the small penumbras in comparison with existing radiosurgery techniques, suggest a potential gain in healthy tissue sparing in this new technique. Biological studies are warranted to assess the effects of pMBRT on both normal and tumoral tissues.
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Affiliation(s)
- Y Prezado
- IMNC-UMR 8165, CNRS, Paris 7 and Paris 11 Universities, Orsay, France.
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20
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Schreiber EC, Chang SX. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology. Med Phys 2012; 39:4669-78. [PMID: 22894391 DOI: 10.1118/1.4728220] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. METHODS Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. RESULTS Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy∕min∕A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. CONCLUSIONS Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak-to-valley ratio for small animal MRT studies.
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Affiliation(s)
- Eric C Schreiber
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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21
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Anderson D, Siegbahn EA, Fallone BG, Serduc R, Warkentin B. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations. Phys Med Biol 2012; 57:3223-48. [PMID: 22546732 DOI: 10.1088/0031-9155/57/10/3223] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm² microbeam array in each phantom, as well as a 16 × 16 mm² array in the 8 cm cat head, and a 32 × 32 mm² array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2-49 (mouse) and 2-46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2-87% and 33-96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this study illustrate that different dose-volume metrics exhibit different functional dependences on MRT geometry parameters, and suggest that reliance on the PVDR as a predictor of therapeutic outcome may be insufficient.
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Affiliation(s)
- Danielle Anderson
- Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada.
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Annabell N, Yagi N, Umetani K, Wong C, Geso M. Evaluating the peak-to-valley dose ratio of synchrotron microbeams using PRESAGE fluorescence. JOURNAL OF SYNCHROTRON RADIATION 2012; 19:332-339. [PMID: 22514166 PMCID: PMC3621279 DOI: 10.1107/s0909049512005237] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 02/06/2012] [Indexed: 05/31/2023]
Abstract
Synchrotron-generated microbeam radiotherapy holds great promise for future treatment, but the high dose gradients present conventional dosimetry with a challenge. Measuring the important peak-to-valley dose ratio (PVDR) of a microbeam-collimated synchrotron source requires both a dosimeter and an analysis method capable of exceptional spatial resolution. The PVDR is of great interest since it is the limiting factor for potential application of the microbeam radiation therapy technique clinically for its tissue-sparing properties (i.e. the valley dose should be below the tolerance of normal tissue). In this work a new method of measuring the dose response of PRESAGE dosimeters is introduced using the fluorescence from a 638 nm laser on a confocal laser-scanning microscope. This fluorescent microscopy method produces dosimetry data at a pixel size as low as 78 nm, giving a much better spatial resolution than optical computed tomography, which is normally used for scanning PRESAGE dosimeters. Using this technique the PVDR of the BL28B2 microbeam at the SPring-8 synchrotron in Japan is estimated to be approximately 52:1 at a depth of 2.5 mm. The PVDR was also estimated with EBT2 GAFchromic films as 30.5:1 at the surface in order to compare the PRESAGE fluorescent results with a more established dosimetry system. This estimation is in good agreement with previously measured ratios using other dosimeters and Monte Carlo simulations. This means that it is possible to use PRESAGE dosimeters with confocal microscopy for the determination of PVDR.
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Affiliation(s)
| | - N. Yagi
- JASRI/SPring-8, Hyogo 679-5198, Japan
| | | | - C. Wong
- William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, Australia
| | - M. Geso
- School of Medical Science, RMIT University, Plenty Road, Melbourne, Victoria 3083, Australia
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Prezado Y, Martínez-Rovira I, Sánchez M. Scatter factors assessment in microbeam radiation therapy. Med Phys 2012; 39:1234-8. [DOI: 10.1118/1.3681274] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Chow JCL, Leung MKK, Fahey S, Chithrani DB, Jaffray DA. Monte Carlo simulation on low-energy electrons from gold nanoparticle in radiotherapy. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/341/1/012012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Martínez-Rovira I, Sempau J, Prezado Y. Development and commissioning of a Monte Carlo photon beam model for the forthcoming clinical trials in microbeam radiation therapy. Med Phys 2011; 39:119-31. [DOI: 10.1118/1.3665768] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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26
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Freudenberg R, Wendisch M, Kotzerke J. Geant4-Simulations for cellular dosimetry in nuclear medicine. Z Med Phys 2011; 21:281-9. [DOI: 10.1016/j.zemedi.2011.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 08/29/2011] [Accepted: 08/29/2011] [Indexed: 10/16/2022]
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McNamara AL, Guatelli S, Prokopovich DA, Reinhard MI, Rosenfeld AB. A comparison of X-ray and proton beam low energy secondary electron track structures using the low energy models of Geant4. Int J Radiat Biol 2011; 88:164-70. [DOI: 10.3109/09553002.2011.627975] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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28
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Prezado Y, Martínez-Rovira I, Thengumpallil S, Deman P. Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy. Med Phys 2011; 38:5012-5020. [DOI: 10.1118/1.3608908] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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29
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Okamoto H, Kohno T, Kanai T, Kase Y, Matsumoto Y, Furusawa Y, Fujita Y, Saitoh H, Itami J. Microdosimetric study on influence of low energy photons on relative biological effectiveness under therapeutic conditions using 6 MV linac. Med Phys 2011; 38:4714-22. [DOI: 10.1118/1.3613152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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30
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Martínez-Rovira I, Prezado Y. Monte Carlo dose enhancement studies in microbeam radiation therapy. Med Phys 2011; 38:4430-9. [DOI: 10.1118/1.3603189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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31
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Leung MKK, Chow JCL, Chithrani BD, Lee MJG, Oms B, Jaffray DA. Irradiation of gold nanoparticles by x-rays: Monte Carlo simulation of dose enhancements and the spatial properties of the secondary electrons production. Med Phys 2011; 38:624-31. [PMID: 21452700 DOI: 10.1118/1.3539623] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE The aim of this study is to understand the characteristics of secondary electrons generated from the interaction of gold nanoparticles (GNPs) with x-rays as a function of nanoparticle size and beam energy and thereby further the understanding of GNP-enhanced radiotherapy. METHODS The effective range, deflection angle, dose deposition, energy, and interaction processes of electrons produced from the interaction of x-rays with a GNP were calculated by Monte Carlo simulations. The GEANT4 code was used to simulate and track electrons generated from a 2, 50, and 100 nm diameter GNP when it is irradiated with a 50 kVp, 250 kVp, cobalt-60, and 6 MV photon beam in water. RESULTS When a GNP was present, depending on the beam energies used, secondary electron production was increased by 10- to 2000-fold compared to an absence of a GNP. Low-energy photon beams were much more efficient at interacting with the GNP by two to three orders of magnitude compared to MV energies and increased the deflection angle. GNPs with larger diameters also contributed more dose. The majority of the energy deposition was outside the GNP, rather than self-absorbed by the nanoparticle. The mean effective range of electron tracks for the beams tested ranged from approximately 3 microm to 1 mm. CONCLUSIONS These simulated results yield important insights concerning the spatial distributions and elevated dose in GNP-enhanced radiotherapy. The authors conclude that the irradiation of GNP at lower photon energies will be more efficient for cell killing. This conclusion is consistent with published studies.
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Affiliation(s)
- Michael K K Leung
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada
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32
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Babcock K, Sidhu N, Kundapur V, Ali K. Collimator design for experimental minibeam radiation therapy. Med Phys 2011; 38:2192-7. [DOI: 10.1118/1.3560425] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Ghasemi M, Kakuee O, Fathollahi V, Shahvar A, Mohati M, Ghafoori M. Physical dose distribution due to multi-sliced kV X-ray beam in labeled tissue-like media: An experimental approach. Appl Radiat Isot 2011; 69:482-91. [DOI: 10.1016/j.apradiso.2010.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 10/06/2010] [Accepted: 10/11/2010] [Indexed: 10/18/2022]
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Okamoto H, Kanai T, Kase Y, Matsumoto Y, Furusawa Y, Fujita Y, Saitoh H, Itami J, Kohno T. Relation between lineal energy distribution and relative biological effectiveness for photon beams according to the microdosimetric kinetic model. JOURNAL OF RADIATION RESEARCH 2011; 52:75-81. [PMID: 21160135 DOI: 10.1269/jrr.10073] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Our cell survival data showed the obvious dependence of RBE on photon energy: The RBE value for 200 kV X-rays was approximately 10% greater than those for mega-voltage photon beams. In radiation therapy using mega-voltage photon beams, the photon energy distribution outside the field is different with that in the radiation field because of a large number of low energy scattering photons. Hence, the RBE values outside the field become greater. To evaluate the increase in RBE, the method of deriving the RBE using the Microdosimetric Kinetic model (MK model) was proposed in this study. The MK model has two kinds of the parameters, tissue-specific parameters and the dose-mean lineal energy derived from the lineal energy distributions measured with a Tissue-Equivalent Proportional Counter (TEPC). The lineal energy distributions with the same geometries of the cell irradiations for 200 kV X-rays, (60)Co γ-rays, and 6 MV X-rays were obtained with the TEPC and Monte Carlo code GEANT4. The measured lineal energy distribution for 200 kV X-rays was quite different from those for mega-voltage photon beams. The dose-mean lineal energy of 200 kV X-rays showed the greatest value, 4.51 keV/µm, comparing with 2.34 and 2.36 keV/µm for (60)Co γ-rays and 6 MV X-rays, respectively. By using the results of the TEPC and cell irradiations, the tissue-specific parameters in the MK model were determined. As a result, the RBE of the photon beams (y(D): 2~5 keV/µm) in arbitrary conditions can be derived by the measurements only or the calculations only of the dose-mean lineal energy.
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Affiliation(s)
- Hiroyuki Okamoto
- Department of Energy Sciences, Tokyo Institute of Technology, Kanagawa, Japan.
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35
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Anschel DJ, Bravin A, Romanelli P. Microbeam radiosurgery using synchrotron-generated submillimetric beams: a new tool for the treatment of brain disorders. Neurosurg Rev 2010; 34:133-42. [DOI: 10.1007/s10143-010-0292-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 08/20/2010] [Accepted: 09/23/2010] [Indexed: 12/01/2022]
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36
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Martínez-Rovira I, Sempau J, Fernández-Varea JM, Bravin A, Prezado Y. Monte Carlo dosimetry for forthcoming clinical trials in x-ray microbeam radiation therapy. Phys Med Biol 2010; 55:4375-88. [DOI: 10.1088/0031-9155/55/15/012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Serduc R, Bouchet A, Bräuer-Krisch E, Laissue JA, Spiga J, Sarun S, Bravin A, Fonta C, Renaud L, Boutonnat J, Siegbahn EA, Estève F, Le Duc G. Synchrotron microbeam radiation therapy for rat brain tumor palliation—influence of the microbeam width at constant valley dose. Phys Med Biol 2009; 54:6711-24. [DOI: 10.1088/0031-9155/54/21/017] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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38
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Prezado Y, Thengumpallil S, Renier M, Bravin A. X-ray energy optimization in minibeam radiation therapy. Med Phys 2009; 36:4897-902. [DOI: 10.1118/1.3232000] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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39
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Prezado Y, Fois G, Le Duc G, Bravin A. Gadolinium dose enhancement studies in microbeam radiation therapy. Med Phys 2009; 36:3568-74. [PMID: 19746791 DOI: 10.1118/1.3166186] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Y Prezado
- ID17 Biomedical Beamline, European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, Boîte Postale 220, 38043 Grenoble Cedex, France.
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40
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Siegbahn EA, Bräuer-Krisch E, Bravin A, Nettelbeck H, Lerch MLF, Rosenfeld AB. MOSFET dosimetry with high spatial resolution in intense synchrotron-generated x-ray microbeams. Med Phys 2009; 36:1128-37. [DOI: 10.1118/1.3081934] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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41
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Nettelbeck H, Takacs GJ, Lerch MLF, Rosenfeld AB. Microbeam radiation therapy: A Monte Carlo study of the influence of the source, multislit collimator, and beam divergence on microbeams. Med Phys 2009; 36:447-56. [DOI: 10.1118/1.3049786] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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42
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Ghasemi M, Shamsaei M, Ghannadi M, Raisali G. Dosimetric studies of micropencil X-ray beam interacting with labelled tissues by Au and Gd agents using Geant4. RADIATION PROTECTION DOSIMETRY 2009; 133:97-104. [PMID: 19223291 DOI: 10.1093/rpd/ncp017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The aim of microbeam radiation therapy is to deliver a high dose to tumours while sparing adjacent healthy tissues. Recovery of normal tissues injured by the beam irradiation and ablation of tumour are dependent on the dose distribution generated by the incident microbeams. Using microbeams has the advantage that the areas outside the beams' trajectories (valley region) are poorly irradiated by the radiation scattered inside the tissues. Thus, the normal tissues not directly irradiated are adequately preserved, resulting in a rapid regeneration of blood vessels in the directly irradiated areas (peak region). The goal of this work was to study the effects of using gold (Au) and gadolinium (Gd) as dose enhancement factors on the radial dose distribution when target tissue is irradiated by a micropencil X-ray beam. The Monte Carlo Geant4 simulation program was used to evaluate dose distribution in the phantom in two phases. In phase 1, validity of this model based on Geant4 was evaluated by comparing the obtained results with those of the published reports. In phase 2 of this simulation, Au and Gd were introduced to the assumed cancerous cylindrical shell-shaped region both on the surface (i.e. in the 0-1 cm depth of phantom) and in the depth (i.e. in the 4-5 cm depth of phantom). Then the phantom was exposed to a micropencil beam mimicking the typical conditions used at the European synchrotron radiation facility in the simulated model. The simulated dose profiles indicate that introducing high Z elements considerably enhances the absorbed dose both in the beam path and in the surrounding region. However, this enhancement is more effective for Au in the beam path and for Gd in the surrounding region. This approach of introducing high Z elements leading to their accumulation in cancerous tissue could hopefully prepare new treatment planning of preclinical trials.
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Affiliation(s)
- M Ghasemi
- Nuclear Engineering and Physics Department, Amirkabir University of Technology, PO Box 15875-4413, Tehran, Iran.
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43
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Chow JCL, Leung MKK. Monte Carlo simulation of MOSFET dosimeter for electron backscatter using the GEANT4
code. Med Phys 2008; 35:2383-90. [DOI: 10.1118/1.2924221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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