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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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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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A Monte Carlo intercomparison of peak-to-valley dose ratios and output factors for microbeam radiation therapy. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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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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5
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Dipuglia A, Cameron M, Davis JA, Cornelius IM, Stevenson AW, Rosenfeld AB, Petasecca M, Corde S, Guatelli S, Lerch MLF. Validation of a Monte Carlo simulation for Microbeam Radiation Therapy on the Imaging and Medical Beamline at the Australian Synchrotron. Sci Rep 2019; 9:17696. [PMID: 31776395 PMCID: PMC6881291 DOI: 10.1038/s41598-019-53991-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 11/05/2019] [Indexed: 01/05/2023] Open
Abstract
Microbeam Radiation Therapy (MRT) is an emerging cancer treatment modality characterised by the use of high-intensity synchrotron-generated x-rays, spatially fractionated by a multi-slit collimator (MSC), to ablate target tumours. The implementation of an accurate treatment planning system, coupled with simulation tools that allow for independent verification of calculated dose distributions are required to ensure optimal treatment outcomes via reliable dose delivery. In this article we present data from the first Geant4 Monte Carlo radiation transport model of the Imaging and Medical Beamline at the Australian Synchrotron. We have developed the model for use as an independent verification tool for experiments in one of three MRT delivery rooms and therefore compare simulation results with equivalent experimental data. The normalised x-ray spectra produced by the Geant4 model and a previously validated analytical model, SPEC, showed very good agreement using wiggler magnetic field strengths of 2 and 3 T. However, the validity of absolute photon flux at the plane of the Phase Space File (PSF) for a fixed number of simulated electrons was unable to be established. This work shows a possible limitation of the G4SynchrotronRadiation process to model synchrotron radiation when using a variable magnetic field. To account for this limitation, experimentally derived normalisation factors for each wiggler field strength determined under reference conditions were implemented. Experimentally measured broadbeam and microbeam dose distributions within a Gammex RMI457 Solid Water® phantom were compared to simulated distributions generated by the Geant4 model. Simulated and measured broadbeam dose distributions agreed within 3% for all investigated configurations and measured depths. Agreement between the simulated and measured microbeam dose distributions agreed within 5% for all investigated configurations and measured depths.
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Affiliation(s)
- Andrew Dipuglia
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Matthew Cameron
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Jeremy A Davis
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Iwan M Cornelius
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Andrew W Stevenson
- CSIRO, Clayton, 3168, Australia
- Imaging and Medical Beamline, ANSTO/Australian Synchrotron, Melbourne, 3168, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Marco Petasecca
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Stéphanie Corde
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
- Department of Radiation Oncology, Prince of Wales Hospital, Randwick, 2031, Australia
| | - Susanna Guatelli
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Michael L F Lerch
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia.
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6
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Identifying optimal clinical scenarios for synchrotron microbeam radiation therapy: A treatment planning study. Phys Med 2019; 60:111-119. [DOI: 10.1016/j.ejmp.2019.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/20/2019] [Accepted: 03/19/2019] [Indexed: 12/25/2022] Open
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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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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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Mukumoto N, Nakayama M, Akasaka H, Shimizu Y, Osuga S, Miyawaki D, Yoshida K, Ejima Y, Miura Y, Umetani K, Kondoh T, Sasaki R. Sparing of tissue by using micro-slit-beam radiation therapy reduces neurotoxicity compared with broad-beam radiation therapy. JOURNAL OF RADIATION RESEARCH 2017; 58:17-23. [PMID: 27422939 PMCID: PMC5321181 DOI: 10.1093/jrr/rrw065] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 04/29/2016] [Accepted: 05/09/2016] [Indexed: 06/06/2023]
Abstract
Micro-slit-beam radiation therapy (MRT) using synchrotron-generated X-ray beams allows for extremely high-dose irradiation. However, the toxicity of MRT in central nervous system (CNS) use is still unknown. To gather baseline toxicological data, we evaluated mortality in normal mice following CNS-targeted MRT. Male C57BL/6 J mice were head-fixed in a stereotaxic frame. Synchrotron X-ray-beam radiation was provided by the SPring-8 BL28B2 beam-line. For MRT, radiation was delivered to groups of mice in a 10 × 12 mm unidirectional array consisting of 25-μm-wide beams spaced 100, 200 or 300 μm apart; another group of mice received the equivalent broad-beam radiation therapy (BRT) for comparison. Peak and valley dose rates of the MRT were 120 and 0.7 Gy/s, respectively. Delivered doses were 96-960 Gy for MRT, and 24-120 Gy for BRT. Mortality was monitored for 90 days post-irradiation. Brain tissue was stained using hematoxylin and eosin to evaluate neural structure. Demyelination was evaluated by Klüver-Barrera staining. The LD50 and LD100 when using MRT were 600 Gy and 720 Gy, respectively, and when using BRT they were 80 Gy and 96 Gy, respectively. In MRT, mortality decreased as the center-to-center beam spacing increased from 100 μm to 300 μm. Cortical architecture was well preserved in MRT, whereas BRT induced various degrees of cerebral hemorrhage and demyelination. MRT was able to deliver extremely high doses of radiation, while still minimizing neuronal death. The valley doses, influenced by beam spacing and irradiated dose, could represent important survival factors for MRT.
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Affiliation(s)
- Naritoshi Mukumoto
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Masao Nakayama
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Hiroaki Akasaka
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Yasuyuki Shimizu
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Saki Osuga
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Daisuke Miyawaki
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Kenji Yoshida
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Yasuo Ejima
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Yasushi Miura
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan
| | - Keiji Umetani
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo, Japan
| | - Takeshi Kondoh
- Department of Neurosurgery, Shinsuma Hospital, Kobe, Hyogo, Japan
| | - Ryohei Sasaki
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
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11
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Lobachevsky P, Ivashkevich A, Forrester HB, Stevenson AW, Hall CJ, Sprung CN, Martin OA. Assessment and Implications of Scattered Microbeam and Broadbeam Synchrotron Radiation for Bystander Effect Studies. Radiat Res 2015; 184:650-9. [PMID: 26632855 DOI: 10.1667/rr13720.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Synchrotron radiation is an excellent tool for investigating bystander effects in cell and animal models because of the well-defined and controllable configuration of the beam. Although synchrotron radiation has many advantages for such studies compared to conventional radiation, the contribution of dose exposure from scattered radiation nevertheless remains a source of concern. Therefore, the influence of scattered radiation on the detection of bystander effects induced by synchrotron radiation in biological in vitro models was evaluated. Radiochromic XRQA2 film-based dosimetry was employed to measure the absorbed dose of scattered radiation in cultured cells at various distances from a field exposed to microbeam radiotherapy and broadbeam X-ray radiation. The level of scattered radiation was dependent on the distance, dose in the target zone and beam mode. The number of γ-H2AX foci in cells positioned at the same target distances was measured and used as a biodosimeter to evaluate the absorbed dose. A correlation of absorbed dose values measured by the physical and biological methods was identified. The γ-H2AX assay successfully quantitated the scattered radiation in the range starting from 10 mGy and its contribution to the observed radiation-induced bystander effect.
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Affiliation(s)
- Pavel Lobachevsky
- a Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC, Australia;,b Sir Peter MacCallum Department of Oncology, the University of Melbourne, Melbourne, VIC, Australia
| | - Alesia Ivashkevich
- c MIMR-PHI Institute of Medical Research and.,e College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, Australia
| | - Helen B Forrester
- c MIMR-PHI Institute of Medical Research and.,d Hudson Institute, Centre for Innate Immunity and Infectious Diseases, Clayton, VIC, Australia;,f Monash University, Department of Molecular and Translational Sciences, Clayton, VIC, Australia
| | - Andrew W Stevenson
- g CSIRO Division of Materials Science and Engineering, Clayton, VIC, Australia;,h Australian Synchrotron, Clayton, VIC, Australia; and
| | - Chris J Hall
- g CSIRO Division of Materials Science and Engineering, Clayton, VIC, Australia
| | - Carl N Sprung
- c MIMR-PHI Institute of Medical Research and.,d Hudson Institute, Centre for Innate Immunity and Infectious Diseases, Clayton, VIC, Australia;,f Monash University, Department of Molecular and Translational Sciences, Clayton, VIC, Australia
| | - Olga A Martin
- a Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC, Australia;,b Sir Peter MacCallum Department of Oncology, the University of Melbourne, Melbourne, VIC, Australia;,i Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC, Australia
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Bräuer-Krisch E, Adam JF, Alagoz E, Bartzsch S, Crosbie J, DeWagter C, Dipuglia A, Donzelli M, Doran S, Fournier P, Kalef-Ezra J, Kock A, Lerch M, McErlean C, Oelfke U, Olko P, Petasecca M, Povoli M, Rosenfeld A, Siegbahn EA, Sporea D, Stugu B. Medical physics aspects of the synchrotron radiation therapies: Microbeam radiation therapy (MRT) and synchrotron stereotactic radiotherapy (SSRT). Phys Med 2015; 31:568-83. [PMID: 26043881 DOI: 10.1016/j.ejmp.2015.04.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 11/19/2022] Open
Abstract
Stereotactic Synchrotron Radiotherapy (SSRT) and Microbeam Radiation Therapy (MRT) are both novel approaches to treat brain tumor and potentially other tumors using synchrotron radiation. Although the techniques differ by their principles, SSRT and MRT share certain common aspects with the possibility of combining their advantages in the future. For MRT, the technique uses highly collimated, quasi-parallel arrays of X-ray microbeams between 50 and 600 keV. Important features of highly brilliant Synchrotron sources are a very small beam divergence and an extremely high dose rate. The minimal beam divergence allows the insertion of so called Multi Slit Collimators (MSC) to produce spatially fractionated beams of typically ∼25-75 micron-wide microplanar beams separated by wider (100-400 microns center-to-center(ctc)) spaces with a very sharp penumbra. Peak entrance doses of several hundreds of Gy are extremely well tolerated by normal tissues and at the same time provide a higher therapeutic index for various tumor models in rodents. The hypothesis of a selective radio-vulnerability of the tumor vasculature versus normal blood vessels by MRT was recently more solidified. SSRT (Synchrotron Stereotactic Radiotherapy) is based on a local drug uptake of high-Z elements in tumors followed by stereotactic irradiation with 80 keV photons to enhance the dose deposition only within the tumor. With SSRT already in its clinical trial stage at the ESRF, most medical physics problems are already solved and the implemented solutions are briefly described, while the medical physics aspects in MRT will be discussed in more detail in this paper.
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Affiliation(s)
- Elke Bräuer-Krisch
- ESRF-The European Synchrotron, 71, Avenue des Martyrs, Grenoble, France.
| | | | - Enver Alagoz
- University of Bergen Department of Physics and Technology, PB 7803 5020, Norway
| | - Stefan Bartzsch
- The Institute of Cancer Research, 15 Cotswold Rd, Sutton SM2 5NG, United Kingdom
| | - Jeff Crosbie
- RMIT University, Melbourne, VIC, 3001, Australia
| | | | - Andrew Dipuglia
- Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, NSW, Australia
| | - Mattia Donzelli
- ESRF-The European Synchrotron, 71, Avenue des Martyrs, Grenoble, France
| | - Simon Doran
- CRUK Cancer Imaging Centre, Institute of Cancer Research, 15 Cotswold Rd, Sutton Surrey, UK
| | - Pauline Fournier
- ESRF-The European Synchrotron, 71, Avenue des Martyrs, Grenoble, France; Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, NSW, Australia
| | - John Kalef-Ezra
- Medical Physics Laboratory, University of Ioannina, 451.10, Ioannina, Greece
| | - Angela Kock
- Sintef Minalab, Gaustadalléen 23C, 0373, Oslo, Norway
| | - Michael Lerch
- Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, NSW, Australia
| | - Ciara McErlean
- CRUK Cancer Imaging Centre, Institute of Cancer Research, 15 Cotswold Rd, Sutton Surrey, UK
| | - Uwe Oelfke
- The Institute of Cancer Research, 15 Cotswold Rd, Sutton SM2 5NG, United Kingdom
| | - Pawel Olko
- Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342, Krawkow, Poland
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, NSW, Australia
| | - Marco Povoli
- University of Oslo, Department of Physics, 0316, Oslo, Norway
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Northfields Ave, NSW, Australia
| | - Erik A Siegbahn
- Department of Oncolgy-Pathology, Karolinska Institutet, S-177176, Stockholm, Sweden
| | - Dan Sporea
- National Institute for Laser, Plasma and Radiation Physics, Magurele, RO-077125, Romania
| | - Bjarne Stugu
- University of Bergen, Department of Physics and Technology, PB 7803, 5020, Bergen, Norway
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Hadsell M, Cao G, Zhang J, Burk L, Schreiber T, Schreiber E, Chang S, Lu J, Zhou O. Pilot study for compact microbeam radiation therapy using a carbon nanotube field emission micro-CT scanner. Med Phys 2014; 41:061710. [PMID: 24877805 PMCID: PMC4032446 DOI: 10.1118/1.4873683] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 04/02/2014] [Accepted: 04/14/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Microbeam radiation therapy (MRT) is defined as the use of parallel, microplanar x-ray beams with an energy spectrum between 50 and 300 keV for cancer treatment and brain radiosurgery. Up until now, the possibilities of MRT have mainly been studied using synchrotron sources due to their high flux (100s Gy/s) and approximately parallel x-ray paths. The authors have proposed a compact x-ray based MRT system capable of delivering MRT dose distributions at a high dose rate. This system would employ carbon nanotube (CNT) field emission technology to create an x-ray source array that surrounds the target of irradiation. Using such a geometry, multiple collimators would shape the irradiation from this array into multiple microbeams that would then overlap or interlace in the target region. This pilot study demonstrates the feasibility of attaining a high dose rate and parallel microbeam beams using such a system. METHODS The microbeam dose distribution was generated by our CNT micro-CT scanner (100 μm focal spot) and a custom-made microbeam collimator. An alignment assembly was fabricated and attached to the scanner in order to collimate and superimpose beams coming from different gantry positions. The MRT dose distribution was measured using two orthogonal radiochromic films embedded inside a cylindrical phantom. This target was irradiated with microbeams incident from 44 different gantry angles to simulate an array of x-ray sources as in the proposed compact CNT-based MRT system. Finally, phantom translation in a direction perpendicular to the microplanar beams was used to simulate the use of multiple parallel microbeams. RESULTS Microbeams delivered from 44 gantry angles were superimposed to form a single microbeam dose distribution in the phantom with a FWHM of 300 μm (calculated value was 290 μm). Also, during the multiple beam simulation, a peak to valley dose ratio of ~10 was found when the phantom translation distance was roughly 4x the beam width. The first prototype CNT-based x-ray tube dedicated to the development of compact MRT technology development was proposed and planned based on the preliminary experimental results presented here and the previous corresponding Monte Carlo simulations. CONCLUSIONS The authors have demonstrated the feasibility of creating microbeam dose distributions at a high dose rate using a proposed compact MRT system. The flexibility of CNT field emission x-ray sources could possibly bring compact and low cost MRT devices to the larger research community and assist in the translational research of this promising new approach to radiation therapy.
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Affiliation(s)
- Mike Hadsell
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Guohua Cao
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jian Zhang
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Laurel Burk
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Torsten Schreiber
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Eric Schreiber
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Sha Chang
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jianping Lu
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Otto Zhou
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599
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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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15
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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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16
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Martínez-Rovira I, Sempau J, Prezado Y. Monte Carlo-based dose calculation engine for minibeam radiation therapy. Phys Med 2013; 30:57-62. [PMID: 23597423 DOI: 10.1016/j.ejmp.2013.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 02/25/2013] [Accepted: 02/28/2013] [Indexed: 10/27/2022] Open
Abstract
Minibeam radiation therapy (MBRT) is an innovative radiotherapy approach based on the well-established tissue sparing effect of arrays of quasi-parallel micrometre-sized beams. In order to guide the preclinical trials in progress at the European Synchrotron Radiation Facility (ESRF), a Monte Carlo-based dose calculation engine has been developed and successfully benchmarked with experimental data in anthropomorphic phantoms. Additionally, a realistic example of treatment plan is presented. Despite the micron scale of the voxels used to tally dose distributions in MBRT, the combination of several efficiency optimisation methods allowed to achieve acceptable computation times for clinical settings (approximately 2 h). The calculation engine can be easily adapted with little or no programming effort to other synchrotron sources or for dose calculations in presence of contrast agents.
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Affiliation(s)
- I Martínez-Rovira
- Service Hospitalier Frédéric Joliot (DSV/I2BM/SHFJ), Commissariat à l'Énergie Atomique et aux énergies alternatives (CEA), 4, Place du Général Leclerc, F-91401 Orsay, France; Institut de Tècniques Energètiques (INTE), Universitat Politècnica de Catalunya (UPC), Diagonal 647, E-08028 Barcelona, Spain; ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), B.P. 220, 6 rue Jules Horowitz, F-38043 Grenoble Cedex, France.
| | - J Sempau
- Institut de Tècniques Energètiques (INTE), Universitat Politècnica de Catalunya (UPC), Diagonal 647, E-08028 Barcelona, Spain; Networking Research Centre, CIBER-BBN, Barcelona, Spain
| | - Y Prezado
- Laboratoire Imagerie et Modélisation en Neurobiologie et Cancérologie, Centre National de la Recherche Scientifique (CNRS), 15 rue Georges Clemenceau, Bât. 440F-91406 Orsay Cedex, France
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17
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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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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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20
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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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Gokeri G, Kocar C, Tombakoglu M. Monte Carlo simulation of microbeam radiation therapy with an interlaced irradiation geometry and an Au contrast agent in a realistic head phantom. Phys Med Biol 2010; 55:7469-87. [DOI: 10.1088/0031-9155/55/24/006] [Citation(s) in RCA: 21] [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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22
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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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23
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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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24
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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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25
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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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26
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Schreiber EC, Chang SX. Monte carlo simulation of an X-ray pixel beam microirradiation system. Radiat Res 2009; 171:332-41. [PMID: 19267560 DOI: 10.1667/rr1453.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Monte Carlo simulations are used in the development of a nanotechnology-based multi-pixel beam array small animal microirradiation system. The microirradiation system uses carbon nanotube field emission technology to generate arrays of individually controllable X-ray pixel beams that electronically form irregular irradiation fields having intensity and temporal modulation without any mechanical motion. The microirradiation system, once developed, will be incorporated with the micro-CT system already developed that is based on the same nanotechnology to form an integrated image-guided and intensity-modulated microirradiation system for high-temporal-resolution small animal research. Prospective microirradiation designs were evaluated based on dosimetry calculated using EGSnrc-based Monte Carlo simulations. Design aspects studied included X-ray anode design, collimator design, and dosimetric considerations such as beam energy, dose rate, inhomogeneity correction, and the microirradiation treatment planning strategies. The dosimetric properties of beam energies between 80-400 kVp with varying filtration were studied, producing a pixel beam dose rate per current of 0.35-13 Gy per min per mA at the microirradiation isocenter. Using opposing multi-pixel-beam array pairs reduces the dose inhomogeneity between adjacent pixel beams to negligible levels near the isocenter and 20% near the mouse surface.
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Affiliation(s)
- E C Schreiber
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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27
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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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28
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Prezado Y, Fois G, Edouard M, Nemoz C, Renier M, Requardt H, Estève F, Adam JF, Elleaume H, Bravin A. Biological equivalent dose studies for dose escalation in the stereotactic synchrotron radiation therapy clinical trials. Med Phys 2009; 36:725-33. [DOI: 10.1118/1.3070538] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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29
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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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30
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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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31
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Crosbie JC, Svalbe I, Midgley SM, Yagi N, Rogers PAW, Lewis RA. A method of dosimetry for synchrotron microbeam radiation therapy using radiochromic films of different sensitivity. Phys Med Biol 2008; 53:6861-77. [DOI: 10.1088/0031-9155/53/23/014] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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32
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Felici MD, Siegbahn EA, Spiga J, Hanson AL, Felici R, Ferrero C, Tartari A, Gambaccini M, Keyriläinen J, Bräuer-Krisch E, Randaccio P, Bravin A. Monte Carlo code comparison of dose delivery prediction for microbeam radiation therapy. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/102/1/012005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Ptaszkiewicz M, Braurer-Kirsch E, Klosowski M, Czopyk L, Olko P. TLD dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility. RADIAT MEAS 2008. [DOI: 10.1016/j.radmeas.2007.12.050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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34
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Spiga J, Siegbahn EA, Bräuer-Krisch E, Randaccio P, Bravin A. The GEANT4
toolkit for microdosimetry calculations: Application to microbeam radiation therapy (MRT). Med Phys 2007; 34:4322-30. [DOI: 10.1118/1.2794170] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Company FZ. Calculation of dose profiles in stereotactic Synchrotron microplanar beam radiotherapy in a tissue-lung phantom. ACTA ACUST UNITED AC 2007; 30:33-41. [PMID: 17508599 DOI: 10.1007/bf03178407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Synchrotron x-ray beams with high fluence rate and highly collimated may be used in stereotactic radiotherapy of lung tumours. A bundle of converging monochromatic x-ray beams having uniform microscopic thickness i.e. (microplanar beams) are directed to the center of the tumour, delivering lethal dose to the target volume while sparing normal cells. The proposed technique takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which regenerate the lethally irradiated endothelial cells. The sharply dropping lateral dose of a microbeam provides low scattered dose to the off-target interbeam volume. In the target volume the converging bundle of beams are closely spaced, and relatively high primary and secondary electron doses overlap and produce a high dose region between the beams. This higher and lower dose margins in the target volume allows precise targeting. The advantages of stereotactic microbeam radiotherapy will be lost as the dose between microbeams exceeds the tolerance dose of the dose limiting tissues. Therefore, it is essential to optimize the interbeam doses in off-target volume. The lateral and depth doses of 100 keV microplanar beams are investigated for a single beam and an array of converging microplanar beams in a tissue, lung and tissue-lung phantoms. The EGS5 Monte Carlo code is used to calculate dose profiles at different depths and bundles of beams. The maximum dose on the beam axis (peak) and the minimum interbeam dose (valley) are compared at different energies, depths, bundle sizes, heights, widths and beam spacings. The interbeam dose is calculated at different depths and an isodose map of the phantom is obtained. An acceptable energy region is found for tissue and lung microbeam radiotherapy and a stereotactic microbeam radiotherapy model is proposed for a 4 cm diameter and 1 cm thick tumour on the lung phantom.
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Affiliation(s)
- F Z Company
- School of Engineering, University of Western Sydney, Kingswood, Australia
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36
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Siegbahn EA, Stepanek J, Bräuer-Krisch E, Bravin A. Determination of dosimetrical quantities used in microbeam radiation therapy (MRT) with Monte Carlo simulations. Med Phys 2006; 33:3248-59. [PMID: 17022219 DOI: 10.1118/1.2229422] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Microbeam radiation therapy (MRT) is being performed by using an array of narrow rectangular x-ray beams (typical beam sizes 25 microm X 1 cm), positioned close to each other (typically 200 microm separation), to irradiate a target tissue. The ratio of peak-to-valley doses (PVDR's) in the composite dose distribution has been found to be strongly correlated with the normal tissue tolerance and the therapeutic effect of MRT. In this work a Monte Carlo (MC) study of the depth- and lateral-dose profiles in water for single x-ray microbeams of different shapes and energies has been performed with the MC code PENELOPE. The contributions to the dose deposition from different interaction types have been determined at different distances from the center of the microbeam. The dependence of the peak dose, in a water phantom, on the microbeam field size used in the preclinical trials, has been demonstrated. Composite dose distributions for an array of microbeams were obtained using superposition algorithms and PVDR's were determined and compared with literature results obtained with other Monte Carlo codes. The dependence of the PVDR's on microbeam width, x-ray energy used, and on the separation between adjacent microbeams has been studied in detail.
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Affiliation(s)
- E A Siegbahn
- European Synchrotron Radiation Facility, B.P.220, 6, rue Horowitz, 38043 Grenoble Cedex, France.
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Dilmanian FA, Zhong Z, Bacarian T, Benveniste H, Romanelli P, Wang R, Welwart J, Yuasa T, Rosen EM, Anschel DJ. Interlaced x-ray microplanar beams: a radiosurgery approach with clinical potential. Proc Natl Acad Sci U S A 2006; 103:9709-14. [PMID: 16760251 PMCID: PMC1480471 DOI: 10.1073/pnas.0603567103] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-microm thick and spaced 100-300 microm on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90-degree angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm(3) exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-microm dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.
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Affiliation(s)
- F Avraham Dilmanian
- Medical Department, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA.
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Serduc R, Vérant P, Vial JC, Farion R, Rocas L, Rémy C, Fadlallah T, Brauer E, Bravin A, Laissue J, Blattmann H, van der Sanden B. In vivo two-photon microscopy study of short-term effects of microbeam irradiation on normal mouse brain microvasculature. Int J Radiat Oncol Biol Phys 2006; 64:1519-27. [PMID: 16580502 DOI: 10.1016/j.ijrobp.2005.11.047] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 11/21/2005] [Accepted: 11/23/2005] [Indexed: 11/21/2022]
Abstract
PURPOSE The purpose of this study was to assess the early effects of microbeam irradiation on the vascular permeability and volume in the parietal cortex of normal nude mice using two-photon microscopy and immunohistochemistry. METHODS AND MATERIALS The upper part of the left hemisphere of 55 mice was irradiated anteroposteriorly using 18 vertically oriented beams (width 25 microm, interdistance 211 microm; peak entrance doses: 312 or 1000 Gy). At different times after microbeam exposure, the microvasculature in the cortex was analyzed using intravital two-photon microscopy after intravascular injection of fluorescein isothiocyanate (FITC)-dextrans and sulforhodamine B (SRB). Changes of the vascular volume were observed at the FITC wavelength over a maximum depth of 650 mum from the dura. The vascular permeability was detected as extravasations of SRB. RESULTS For all times (12 h to 1 month) after microbeam irradiation and for both doses, the FITC-dextran remained in the vessels. No significant change in vascular volume was observed between 12 h and 3 months after irradiation. Diffusion of SRB was observed in microbeam irradiated regions from 12 h until 12 days only after a 1000 Gy exposure. CONCLUSION No radiation damage to the microvasculature was detected in normal brain tissue after a 312 Gy microbeam irradiation. This dose would be more appropriate than 1000 Gy for the treatment of brain tumors using crossfired microbeams.
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Affiliation(s)
- Raphaël Serduc
- INSERM, U 594, Functional and Metabolic Neuroimaging, Grenoble, France; Université Joseph Fourier Grenoble, Grenoble, France.
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De Felici M, Felici R, Sanchez del Rio M, Ferrero C, Bacarian T, Dilmanian FA. Dose distribution from x‐ray microbeam arrays applied to radiation therapy: An
EGS4
Monte Carlo study. Med Phys 2005; 32:2455-63. [PMID: 16193774 DOI: 10.1118/1.1951043] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We present EGS4 Monte Carlo calculations of the spatial distribution of the dose deposited by a single x-ray pencil beam, a planar microbeam, and an array of parallel planar microbeams as used in radiation therapy research. The profiles of the absorbed dose distribution in a phantom, including the peak-to-valley ratio of the dose distribution from microbeam arrays, were calculated at micrometer resolution. We determined the dependence of the findings on the main parameters of photon and electron transport. The results illustrate the dependence of the electron range and the deposited in-beam dose on the cut-off energy, of the electron transport, as well as the effects on the dose profiles of the beam energy, the array size, and the beam spacing. The effect of beam polarization also was studied for a single pencil beam and for an array of parallel planar microbeams. The results show that although the polarization effect on the dose distribution from a 3 cm x 3 cm microbeam array inside a water phantom is large enough to be measured at the outer side of the array (16% difference of the deposited dose for x-ray beams of 200 keV), it is not detectable at the array's center, thus being irrelevant for the radiation therapy purposes. Finally we show that to properly compare the dose profiles determined with a metal oxide semiconductor field emission transistor detector with the computational method predictions, it is important to simulate adequately the size and the material of the device's Si active element.
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Affiliation(s)
- M De Felici
- INFM-OGG, c/o ESRF, BP220, F-38043 Grenoble Cedex, France.
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40
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Bräuer-Krisch E, Requardt H, Régnard P, Corde S, Siegbahn E, LeDuc G, Brochard T, Blattmann H, Laissue J, Bravin A. New irradiation geometry for microbeam radiation therapy. Phys Med Biol 2005; 50:3103-11. [PMID: 15972983 DOI: 10.1088/0031-9155/50/13/009] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays.
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Affiliation(s)
- E Bräuer-Krisch
- European Synchrotron Radiation Facility, BP 220, 6, rue Horowitz, 38043 Grenoble Cedex, France.
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van der Have F, Beekman FJ. Photon penetration and scatter in micro-pinhole imaging: a Monte Carlo investigation. Phys Med Biol 2004; 49:1369-86. [PMID: 15152680 DOI: 10.1088/0031-9155/49/8/001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pinhole SPECT is rapidly gaining popularity for imaging laboratory animals using gamma-emitting molecules. Penetration and scattering of gamma radiation in the pinhole edge material can account for a significant fraction of the total number of photons detected, particularly if the pinholes have small diameters. This study characterizes the effects of penetration and scatter with micro-pinholes made of lead, tungsten, gold and platinum. Monte Carlo simulations are performed for 1-125 (27-35 keV) and Tc-99m (140 keV) point sources with pinhole diameters ranging from 50 to 500 microm. The simulations account for the effects of photo-electric interaction, Rayleigh scattering, Compton scattering, ionization, bremsstrahlung and electron multiple scattering. As a typical example, in the case of a Tc-99m point source and pinholes with a diameter of 300 microm in gold or platinum, approximately 55% of the photons detected resulted from penetration and approximately 3% from scatter. For pinhole diameters ranging from 100 to 500 microm, the penetration fraction for tungsten and lead was approx a factor of 1.0 to 1.6 higher and the scatter fraction was 1.0 to 1.8 times higher than in case of gold or platinum. Using I-125 instead of Tc-99m decreases the penetration fraction by a factor ranging from 3 to 11 and the scatter fraction by a factor ranging from 12 to 40. For all materials studied, the total amounts of penetrated and scattered photons changed approximately linearly with respect to the pinhole diameter.
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Affiliation(s)
- Frans van der Have
- Image Sciences Institute, UMC Utrecht STR 5.203, Universiteitsweg 100. 3584 CG Utrecht, The Netherlands.
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Comparison of Monte Carlo simulations of photon/electron dosimetry in microscale applications. ACTA ACUST UNITED AC 2003. [DOI: 10.1007/bf03178459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bräuer-Krisch E, Bravin A, Lerch M, Rosenfeld A, Stepanek J, Di Michiel M, Laissue JA. MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility. Med Phys 2003; 30:583-9. [PMID: 12722810 DOI: 10.1118/1.1562169] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Preclinical experiments are carried out with approximately 20-30 microm wide, approximately 10 mm high parallel microbeams of hard, broad-"white"-spectrum x rays (approximately 50-600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. Novel physical microdosimetry (implemented with MOSFET chips in the "edge-on" mode) and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue-equivalent phantom. Such microbeam irradiation causes minimal damage to normal tissues, possible because of rapid repair of their microscopic lesions. Radiation damage from an array of parallel microbeams tends to correlate with the range of peak-valley dose ratios (PVDR). This paper summarizes comparisons of our dosimetric MOSFET measurements with Monte Carlo calculations. Peak doses at depths <22 mm are 18% less than Monte Carlo values, whereas those depths >22 mm and valley doses at all depths investigated (2 mm-62 mm) are within 2-13% of the Monte Carlo values. These results lend credence to the use of MOSFET detector systems in edge-on mode for microplanar irradiation dosimetry.
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Affiliation(s)
- E Bräuer-Krisch
- European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble, France
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