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Dosimetry procedure to verify dose in High Dose Rate (HDR) brachytherapy treatment of cancer patients: A systematic review. Phys Med 2022; 96:70-80. [DOI: 10.1016/j.ejmp.2022.02.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 01/12/2023] Open
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Gonod M, Chacon Avila C, Suarez MA, Crouzilles J, Laskri S, Vinchant JF, Aubignac L, Grosjean T. Miniaturized scintillator dosimeter for small field radiation therapy. Phys Med Biol 2021; 66. [PMID: 33971635 DOI: 10.1088/1361-6560/abffbb] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 05/10/2021] [Indexed: 11/11/2022]
Abstract
The concept of a miniaturized inorganic scintillator detector is demonstrated in the analysis of the small static photon fields used in external radiation therapy. Such a detector is constituted by a 0.25 mm diameter and 0.48 mm long inorganic scintillating cell (1.6 × 10-5cm3detection volume) efficiently coupled to a narrow 125μm diameter silica optical fiber using a tiny photonic interface (an optical antenna). The response of our miniaturized scintillator detector (MSD) under 6 MV bremsstrahlung beam of various sizes (from 1 × 1 cm2to 4 × 4 cm2) is compared to that of two high resolution reference probes, namely, a micro-diamond detector and a dedicated silicon diode. The spurious Cerenkov signal transmitted through our bare detector is rejected with a basic spectral filtering. The MSD shows a linear response regarding the dose, a repeatability within 0.1% and a radial directional dependence of 0.36% (standard deviations). Beam profiling at 5 cm depth with the MSD and the micro-diamond detector shows a mismatch in the measurement of the full widths at 80% and 50% of the maximum which does not exceed 0.25 mm. The same difference range is found between the micro-diamond detector and a silicon diode. The deviation of the percentage depth dose between the MSD and micro-diamond detector remains below 2.3% within the first fifteen centimeters of the decay region for field sizes of 1 × 1 cm2, 2 × 2 cm2and 3 × 3 cm2(0.76% between the silicon diode and the micro-diamond in the same field range). The 2D dose mapping of a 0.6 × 0.6 cm2photon field evidences the strong 3D character of the radiation-matter interaction in small photon field regime. From a beam-probe convolution theory, we predict that our probe overestimates the beam width by 0.06%, making our detector a right compromise between high resolution, compactness, flexibility and ease of use. The MSD overcomes problem of volume averaging, stem effects, and despite its water non-equivalence it is expected to minimize electron fluence perturbation due to its extreme compactness. Such a detector thus has the potential to become a valuable dose verification tool in small field radiation therapy, and by extension in Brachytherapy, FLASH-radiotherapy and microbeam radiation therapy.
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Affiliation(s)
- Mathieu Gonod
- Centre Georges François Leclerc (CGFL)-Dijon, France
| | - Carlos Chacon Avila
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Bourgogne Franche-Comté-CNRS-Besançon, France
| | - Miguel Angel Suarez
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Bourgogne Franche-Comté-CNRS-Besançon, France
| | - Julien Crouzilles
- SEDI-ATI Fibres Optiques, 8 Rue Jean Mermoz, F-91080 Évry-Courcouronnes, France
| | - Samir Laskri
- SEDI-ATI Fibres Optiques, 8 Rue Jean Mermoz, F-91080 Évry-Courcouronnes, France
| | | | | | - Thierry Grosjean
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Bourgogne Franche-Comté-CNRS-Besançon, France
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Ding L, Wu Q, Wang Q, Li Y, Perks RM, Zhao L. Advances on inorganic scintillator-based optic fiber dosimeters. EJNMMI Phys 2020; 7:60. [PMID: 33025267 PMCID: PMC7538482 DOI: 10.1186/s40658-020-00327-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 09/03/2020] [Indexed: 12/19/2022] Open
Abstract
This article presents a new perspective on the development of inorganic scintillator-based fiber dosimeters (IOSFDs) for medical radiotherapy dosimetry (RTD) focusing on real-time in vivo dosimetry. The scintillator-based optical fiber dosimeters (SFD) are compact, free of electromagnetic interference, radiation-resistant, and robust. They have shown great potential for real-time in vivo RTD. Compared with organic scintillators (OSs), inorganic scintillators (IOSs) have larger X-ray absorption and higher light output. Variable IOSs with maximum emission peaks in the red part of the spectrum offer convenient stem effect removal. This article outlines the main advantages and disadvantages of utilizing IOSs for SFD fabrication. IOSFDs with different configurations are presented, and their use for dosimetry in X-ray RT, brachytherapy (BT), proton therapy (PT), and boron neutron capture therapy (BNCT) is reviewed. Challenges including the percentage depth dose (PDD) deviation from the standard ion chamber (IC) measurement, the angular dependence, and the Cherenkov effect are discussed in detail; methods to overcome these problems are also presented.
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Affiliation(s)
- Liang Ding
- School of Engineering, Cardiff University, Cardiff, UK
| | - Qiong Wu
- Department of Pharmacy, General Hospital of Southern Theatre Command, Guangzhou, China
| | - Qun Wang
- Department of Pharmacy, Shanghai Baoshan Luodian Hospital, Shanghai, China
| | - Yamei Li
- Department of Pharmacy, Shanghai Baoshan Luodian Hospital, Shanghai, China
| | | | - Liang Zhao
- Department of Pharmacy, Shanghai Baoshan Luodian Hospital, Shanghai, China
- Institute for Translational Medicine Research, Shanghai University, Shanghai, China
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Yada R, Maenaka K, Miyamoto S, Okada G, Sasakura A, Ashida M, Adachi M, Sato T, Wang T, Akasaka H, Mukumoto N, Shimizu Y, Sasaki R. Real-time in vivo dosimetry system based on an optical fiber-coupled microsized photostimulable phosphor for stereotactic body radiation therapy. Med Phys 2020; 47:5235-5249. [PMID: 32654194 DOI: 10.1002/mp.14383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/21/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To develop an in vivo dosimeter system for stereotactic body radiation therapy (SBRT) that can perform accurate and precise real-time measurements, using a microsized amount of a photostimulable phosphor (PSP), BaFBr:Eu2+ . METHODS The sensitive volume of the PSP was 1.26 × 10-5 cm3 . The dosimeter system was designed to apply photostimulation to the PSP after the decay of noise signals, in synchronization with the photon beam pulse of a linear accelerator (LINAC), to eliminate the noise signals completely using a time separation technique. The noise signals included stem signals, and radioluminescence signals generated by the PSP. In addition, the dosimeter system was built on a storage-type dosimeter that could read out a signal after an arbitrary preset number of photon beam pulses were incident. First, the noise and photostimulated luminescence (PSL) signal decay times were measured. Subsequently, we confirmed that the PSL signals could be exclusively read out within the photon beam pulse interval. Finally, using a water phantom, the basic characteristics of the dosimeter system were demonstrated under SBRT conditions, and the feasibility for clinical application was investigated. The reproducibility, dose linearity, dose-rate dependence, temperature dependence, and angular dependence were evaluated. The feasibility was confirmed by measurements at various dose gradients and using a representative treatment plan for a metastatic liver tumor. A clinical plan was created with a two-arc beam volumetric modulated arc therapy using a 10 MV flattening filter-free photon beam. For the water phantom measurements, the clinical plan was compiled into a plan with a fixed gantry angle of 0°. To evaluate the energy dependence during SBRT, the percent depth dose (PDD) was measured and compared with those calculated via Monte Carlo (MC) simulations. RESULTS All the PSL signals could be read out while eliminating the noise signals within the minimum pulse interval of the LINAC. Stable real-time measurements could be performed with a time resolution of 56 ms (i.e., number of pulses = 20). The dose linearity was good in the dose range of 0.01-100 Gy. The measurements agreed within 1% at dose rates of 40-2400 cGy/min. The temperature and angular dependence were also acceptable since these dependencies had only a negligible effect on the measurements in SBRT. At a dose gradient of 2.21 Gy/mm, the measured dose agreed with that calculated using a treatment planning system (TPS) within the measurement uncertainties due to the probe position. For measurements using a representative treatment plan, the measured dose agreed with that calculated using the TPS within 0.5% at the center of the beam axis. The PDD measurements agreed with the MC calculations to within 1% for field sizes <5 × 5 cm2 . CONCLUSION The in vivo dosimeter system developed using BaFBr:Eu2+ is capable of real-time, accurate, and precise measurement under SBRT conditions. The probe is smaller than a conventional dosimeter, has excellent spatial resolution, and can be valuable in SBRT with a steep dose distribution over a small field. The developed PSP dosimeter system appears to be suitable for in vivo SBRT dosimetry.
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Affiliation(s)
- Ryuichi Yada
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuouku, Kobe, Hyogo, 650-0017, Japan
| | - Kazusuke Maenaka
- Department of Electrical Engineering and Computer Science, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2280, Japan
| | - Shuji Miyamoto
- Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigoricho, Akogun, Hyogo, 678-1205, Japan
| | - Go Okada
- Co-creative Research Center of Industrial Science and Technology, Kanazawa Institute of Technology, 3-1 Yatsukaho, Hakusan, Ishikawa, 924-0838, Japan
| | - Aki Sasakura
- Meisyo Kiko Co., Ltd, 148 Numa, Hikamicho, Tamba, Hyogo, 669-3634, Japan
| | - Motoi Ashida
- Meisyo Kiko Co., Ltd, 148 Numa, Hikamicho, Tamba, Hyogo, 669-3634, Japan
| | - Masashi Adachi
- Meisyo Kiko Co., Ltd, 148 Numa, Hikamicho, Tamba, Hyogo, 669-3634, Japan
| | - Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Tianyuan Wang
- 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
| | - Naritoshi Mukumoto
- 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
| | - 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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Alharbi M, Martyn M, O'Keeffe S, Therriault-Proulx F, Beaulieu L, Foley M. Benchmarking a novel inorganic scintillation detector for applications in radiation therapy. Phys Med 2019; 68:124-131. [DOI: 10.1016/j.ejmp.2019.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/29/2019] [Accepted: 11/18/2019] [Indexed: 11/29/2022] Open
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Abstract
Many brachytherapy (BT) errors could be detected with real-time in vivo dosimetry technology. Inorganic scintillation detectors (ISDs) have demonstrated promising capabilities for BT, because some ISD materials can generate scintillation signals large enough that (a) the background signal emitted in the fiber-optic cable (stem signal) is insignificant, and (b) small detector volumes can be used to avoid volume averaging effects in steep dose gradients near BT sources. We investigated the characteristics of five ISD materials to identify one that is appropriate for BT. ISDs consisting of a 0.26 to 1.0 mm3 volume of ruby (Al2O3:Cr), a mixture of Y2O3:Eu and YVO4:Eu, ZnSe:O, or CsI:Tl coupled to a fiber-optic cable were irradiated in a water-equivalent phantom using a high-dose-rate 192Ir BT source. Detectors based on plastic scintillators BCF-12 and BCF-60 (0.8 mm3 volume) were used as a reference. Measurements demonstrated that the ruby, Y2O3:Eu+YVO4:Eu, ZnSe:O, and CsI:Tl ISDs emitted scintillation signals that were up to 19, 19, 250, and 880 times greater, respectively, than that of the BCF-12 detector. While the total signals of the plastic scintillation detectors were dominated by the stem signal for source positions 0.5 cm from the fiber-optic cable and >3.5 cm from the scintillator volume, the stem signal for the ruby and Y2O3:Eu+YVO4:Eu ISDs were <1% of the total signal for source positions <3.4 and <4.4 cm from the scintillator, respectively, and <0.7% and <0.5% for the ZnSe:O and CsI:Tl ISDs, respectively, for positions ⩽8.0 cm. In contrast to the other ISDs, the Y2O3:Eu+YVO4:Eu ISD exhibited unstable scintillation and significant afterglow. All ISDs exhibited significant energy dependence, i.e. their dose response to distance-dependent 192Ir energy spectra differed significantly from the absorbed dose in water. Provided that energy dependence is accounted for, ZnSe:O ISDs are promising for use in error detection and patient safety monitoring during BT.
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Affiliation(s)
- Gustavo Kertzscher
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
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Kertzscher G, Beddar S. Inorganic scintillation detectors based on Eu-activated phosphors for 192Ir brachytherapy. Phys Med Biol 2017; 62:5046-5075. [PMID: 28475494 DOI: 10.1088/1361-6560/aa716e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The availability of real-time treatment verification during high-dose-rate (HDR) brachytherapy is currently limited. Therefore, we studied the luminescence properties of the widely commercially available scintillators using the inorganic materials Eu-activated phosphors Y2O3:Eu, YVO4:Eu, Y2O2S:Eu, and Gd2O2S:Eu to determine whether they could be used to accurately and precisely verify HDR brachytherapy doses in real time. The suitability for HDR brachytherapy of inorganic scintillation detectors (ISDs) based on the 4 Eu-activated phosphors in powder form was determined based on experiments with a 192Ir HDR brachytherapy source. The scintillation intensities of the phosphors were 16-134 times greater than that of the commonly used organic plastic scintillator BCF-12. High signal intensities were achieved with an optimized packing density of the phosphor mixture and with a shortened fiber-optic cable. The influence of contaminating Cerenkov and fluorescence light induced in the fiber-optic cable (stem signal) was adequately suppressed by inserting between the fiber-optic cable and the photodetector a 25 nm band-pass filter centered at the emission peak. The spurious photoluminescence signal induced by the stem signal was suppressed by placing a long-pass filter between the scintillation detector volume and the fiber-optic cable. The time-dependent luminescence properties of the phosphors were quantified by measuring the non-constant scintillation during irradiation and the afterglow after the brachytherapy source had retracted. We demonstrated that a mixture of Y2O3:Eu and YVO4:Eu suppressed the time-dependence of the ISDs and that the time-dependence of Y2O2S:Eu and Gd2O2S:Eu introduced large measurement inaccuracies. We conclude that ISDs based on a mixture of Y2O3:Eu and YVO4:Eu are promising candidates for accurate and precise real-time verification technology for HDR BT that is cost effective and straightforward to manufacture. Widespread dissemination of this technology could lead to an improved understanding of error types and frequencies during BT and to improved patient safety during treatment.
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Affiliation(s)
- Gustavo Kertzscher
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
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Kertzscher G, Beddar S. Ruby-based inorganic scintillation detectors for 192Ir brachytherapy. Phys Med Biol 2016; 61:7744-7764. [PMID: 27740947 DOI: 10.1088/0031-9155/61/21/7744] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from >5% to <1% of the total signal as long as the ISD incorporated the long-pass filter. The stem signal was suppressed with a band-pass filter and was <3% as long as the source distance from the scintillator was <7 cm. Some ruby crystals exhibited time-dependent luminescence properties that altered the ruby signal by >5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence.
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Affiliation(s)
- Gustavo Kertzscher
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Ramírez M, Martínez N, Marcazzó J, Molina P, Feld D, Santiago M. Performance of ZnSe(Te) as fiberoptic dosimetry detector. Appl Radiat Isot 2016; 116:1-7. [PMID: 27472824 DOI: 10.1016/j.apradiso.2016.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 06/29/2016] [Accepted: 07/10/2016] [Indexed: 10/21/2022]
Abstract
Fiberoptic dosimetry (FOD) is an experimental technique suitable for in-vivo, real time dosimetry in radiotherapy treatments. FOD relies on using a small scintillator coupled to one end of a long optical fiber. The scintillator is placed at the point where the dose rate is to be determined whereas a light detector at the other end of the fiber measures the intensity of the radioluminescence emitted by the scintillator. One of the problems hampering the straightforward application of this technique in clinics is the presence of Cherenkov radiation generated in the fiber by the ionizing radiation, which adds to the scintillating light and introduces a bias in the dose measurement. Since Cherenkov radiation is more important in short wavelength range of the visible spectrum, using red-emitting scintillators as FOD detectors permits to reduce the Cherenkov contribution by using optical filters. In this work, the performance of red-emitting tellurium-doped zinc selenide crystal as FOD detector is evaluated and compared to the response of an ion-chamber.
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Affiliation(s)
- M Ramírez
- Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA - CICPBA - CONICET), Pinto 399, 7000 Tandil, Argentina; Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano (ITM), Calle 73 No 76 A 354, Medellín, Colombia
| | - N Martínez
- Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA - CICPBA - CONICET), Pinto 399, 7000 Tandil, Argentina
| | - J Marcazzó
- Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA - CICPBA - CONICET), Pinto 399, 7000 Tandil, Argentina
| | - P Molina
- Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA - CICPBA - CONICET), Pinto 399, 7000 Tandil, Argentina
| | - D Feld
- Instituto de Oncología Ángel H. Roffo, Av. San Martín, CABA, 5481 Argentina
| | - M Santiago
- Instituto de Física Arroyo Seco (UNCPBA) and CIFICEN (UNCPBA - CICPBA - CONICET), Pinto 399, 7000 Tandil, Argentina
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Scintillation properties of the YVO4:Eu3+ compound in powder form: its application to dosimetry in radiation fields produced by pulsed mega-voltage photon beams. Z Med Phys 2015; 25:368-374. [DOI: 10.1016/j.zemedi.2015.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/01/2015] [Accepted: 04/04/2015] [Indexed: 11/23/2022]
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