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Selva A, Bianchi A, Cirrone GAP, Petringa G, Romano F, Schettino G, Conte V. Sensitivity of a mini-TEPC to radiation quality variations in clinical proton beams. Phys Med 2024; 118:103201. [PMID: 38199179 DOI: 10.1016/j.ejmp.2023.103201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/30/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
PURPOSE This work aims at studying the sensitivity of a miniaturized Tissue-Equivalent Proportional Counter to variations of beam quality in clinical radiation fields, to further investigate its performances as radiation quality monitor. METHODS Measurements were taken at the CATANA facility (INFN-LNS, Catania, Italy), in a monoenergetic and an energy-modulated proton beam with the same initial energy of 62 MeV. PMMA layers were placed in front of the detector to measure at different depths along the depth-dose profile. The frequency- and dose-mean lineal energy were compared to the track- and dose-averaged LET calculated by Monte Carlo simulations. A microdosimetric evaluation of the Relative Biological Effectiveness (RBE) was performed and compared with cell survival experiments. RESULTS Microdosimetric distributions measured at identical depths in the two beams show spectral differences reflecting their different radiation quality. Discrepancies are most evident at depths corresponding to the Spread-Out Bragg Peak, while spectra at the entrance and in the dose fall-off regions are similar. This can be explained by the different energy components that compose the pristine and spread-out peaks at each depth. The trend of microdosimetric mean values matches that of calculated LET averages along the entire penetration depth, and the microdosimetric estimation of RBE is consistent with radiobiological data not only at 2 Gy but also at lower dose levels, such as those absorbed by healthy tissues. CONCLUSIONS The mini-TEPC is sensitive to differences in radiation quality resulting from different modulations of the proton beam, confirming its potential for beam quality monitoring in proton therapy.
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Affiliation(s)
- A Selva
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy.
| | - A Bianchi
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy
| | | | - G Petringa
- INFN Laboratori Nazionali del Sud, Catania, Italy
| | - F Romano
- INFN Sezione di Catania, Catania, Italy
| | - G Schettino
- National Physical Laboratory, Medical Radiation Science, Teddington, UK
| | - V Conte
- INFN Laboratori Nazionali di Legnaro, Legnaro, Italy
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Han Y, Geng C, D-Kondo JN, Li M, Ramos-Méndez J, Altieri S, Liu Y, Tang X. Microdosimetric Analysis for Boron Neutron Capture Therapy via Monte Carlo Track Structure Simulation with Modified Lithium Cross-sections. Radiat Phys Chem Oxf Engl 1993 2023; 209:110956. [PMID: 37206625 PMCID: PMC10191410 DOI: 10.1016/j.radphyschem.2023.110956] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Boron neutron capture therapy (BNCT) is a cellular-level hadron therapy achieving therapeutic effects via the synergistic action of multiple particles, including Lithium, alpha, proton, and photon. However, evaluating the relative biological effectiveness (RBE) in BNCT remains challenging. In this research, we performed a microdosimetric calculation for BNCT using the Monte Carlo track structure (MCTS) simulation toolkit, TOPAS-nBio. This paper reports the first attempt to derive the ionization cross-sections of low-energy (>0.025 MeV/u) Lithium for MCTS simulation based on the effective charge cross-section scalation method and phenomenological double-parameter modification. The fitting parameters λ1=1.101,λ2=3.486 were determined to reproduce the range and stopping power data from the ICRU report 73. Besides, the lineal energy spectra of charged particles in BNCT were calculated, and the influence of sensitive volume (SV) size was discussed. Condensed history simulation obtained similar results with MCTS when using Micron-SV while overestimating the lineal energy when using Nano-SV. Furthermore, we found that the microscopic boron distribution can significantly affect the lineal energy for Lithium, while the effect for alpha is minimal. Similar results to the published data by PHITS simulation were observed for the compound particles and monoenergetic protons when using micron-SV. Spectra with nano-SV reflected that the different track densities and absorbed doses in the nucleus together result in the dramatic difference in the macroscopic biological response of BPA and BSH. This work and the developed methodology could impact the research fields in BNCT where understanding radiation effects is crucial, such as the treatment planning system, source evaluation, and new boron drug development.
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Affiliation(s)
- Yang Han
- Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Technology, Nanjing, 210016, China
- Joint International Research Laboratory on Advanced Particle Therapy, Nanjing 211100, China
- University of Pavia, Department of Physics, Pavia, 27100, Italy
| | - Changran Geng
- Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Technology, Nanjing, 210016, China
- Joint International Research Laboratory on Advanced Particle Therapy, Nanjing 211100, China
- (+86 13601582233), (+86 15380796769)
| | - J. Naoki D-Kondo
- University of California San Francisco, Department of Radiation Oncology, San Francisco, CA 94115, USA
| | - Mingzhu Li
- Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Technology, Nanjing, 210016, China
- Joint International Research Laboratory on Advanced Particle Therapy, Nanjing 211100, China
| | - José Ramos-Méndez
- University of California San Francisco, Department of Radiation Oncology, San Francisco, CA 94115, USA
| | - Saverio Altieri
- University of Pavia, Department of Physics, Pavia, 27100, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), the section of Pavia, Pavia, 27100, Italy
| | - Yuanhao Liu
- Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Technology, Nanjing, 210016, China
- Joint International Research Laboratory on Advanced Particle Therapy, Nanjing 211100, China
| | - Xiaobin Tang
- Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Technology, Nanjing, 210016, China
- Joint International Research Laboratory on Advanced Particle Therapy, Nanjing 211100, China
- (+86 13601582233), (+86 15380796769)
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Koniar H, Miller C, Rahmim A, Schaffer P, Uribe C. A GATE simulation study for dosimetry in cancer cell and micrometastasis from the 225Ac decay chain. EJNMMI Phys 2023; 10:46. [PMID: 37525027 PMCID: PMC10390455 DOI: 10.1186/s40658-023-00564-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 07/24/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Radiopharmaceutical therapy (RPT) with alpha-emitting radionuclides has shown great promise in treating metastatic cancers. The successive emission of four alpha particles in the 225Ac decay chain leads to highly targeted and effective cancer cell death. Quantifying cellular dosimetry for 225Ac RPT is essential for predicting cell survival and therapeutic success. However, the leading assumption that all 225Ac progeny remain localized at their target sites likely overestimates the absorbed dose to cancer cells. To address limitations in existing semi-analytic approaches, this work evaluates S-values for 225Ac's progeny radionuclides with GATE Monte Carlo simulations. METHODS The cellular geometries considered were an individual cell (10 µm diameter with a nucleus of 8 µm diameter) and a cluster of cells (micrometastasis) with radionuclides localized in four subcellular regions: cell membrane, cytoplasm, nucleus, or whole cell. The absorbed dose to the cell nucleus was scored, and self- and cross-dose S-values were derived. We also evaluated the total absorbed dose with various degrees of radiopharmaceutical internalization and retention of the progeny radionuclides 221Fr (t1/2 = 4.80 m) and 213Bi (t1/2 = 45.6 m). RESULTS For the cumulative 225Ac decay chain, our self- and cross-dose nuclear S-values were both in good agreement with S-values published by MIRDcell, with per cent differences ranging from - 2.7 to - 8.7% for the various radionuclide source locations. Source location had greater effects on self-dose S-values than the intercellular cross-dose S-values. Cumulative 225Ac decay chain self-dose S-values increased from 0.167 to 0.364 GyBq-1 s-1 with radionuclide internalization from the cell surface into the cell. When progeny migration from the target site was modelled, the cumulative self-dose S-values to the cell nucleus decreased by up to 71% and 21% for 221Fr and 213Bi retention, respectively. CONCLUSIONS Our GATE Monte Carlo simulations resulted in cellular S-values in agreement with existing MIRD S-values for the alpha-emitting radionuclides in the 225Ac decay chain. To obtain accurate absorbed dose estimates in 225Ac studies, accurate understanding of daughter migration is critical for optimized injected activities. Future work will investigate other novel preclinical alpha-emitting radionuclides to evaluate therapeutic potency and explore realistic cellular geometries corresponding to targeted cancer cell lines.
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Affiliation(s)
- Helena Koniar
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.
| | - Cassandra Miller
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Arman Rahmim
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Carlos Uribe
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Functional Imaging, BC Cancer, Vancouver, BC, Canada
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Sato T, Matsuya Y, Ogawa T, Kai T, Hirata Y, Tsuda S, Parisi A. Improvement of the hybrid approach between Monte Carlo simulation and analytical function for calculating microdosimetric probability densities in macroscopic matter. Phys Med Biol 2023. [PMID: 37352865 DOI: 10.1088/1361-6560/ace14c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2023]
Abstract
OBJECTIVE Estimate of the probability density of the microdosimetric quantities in macroscopic matter is indispensable for applying the concept of microdosimetry to medical physics and radiological protection. Particle and Heavy Ion Transport code System (PHITS) enables estimating the microdosimetric probability densities due to its unique hybrid modality between the Monte Carlo and analytical approaches called the microdosimetric function. It can convert the deposition energies calculated by the macroscopic Monte Carlo radiation transport simulation to microdosimetric probability densities in water using an analytical function based on the track-structure simulations. METHODOLOGY In this study, we improved this function using the latest track-structure simulation codes implemented in PHITS. The improved function is capable of calculating the probability densities of not only the conventional microdosimetric quantities such as lineal energy but also the numbers of ionization events occurred in a target site, the so-called ionization cluster size distribution, for arbitrary site diameters from 3 nm to 1 μm. MAIN RESULTS The accuracy of the improved function was well verified by comparing the microdosimetric probability densities measured by tissue-equivalent proportional counters with the corresponding data calculated in this study. Test calculations for clonogenic cell survival using the improved function coupled with the modified microdosimetric kinetic model suggested a slight increase of its relative biological effectiveness compared with our previous estimations. As a new application of the improved function, we calculated the relative biological effectiveness of the single-strand break and double-strand break yields for proton irradiations using the updated PHITS coupled with the simplified DNA damage estimation model, and confirmed its equivalence in accuracy and its superiority in computational time compared to our previously proposed method based on the track-structure simulation. SIGNIFICANCE From these features, we concluded that the improved function could expand the application fields of PHITS by bridging the gap between microdosimetry and macrodosimetry.
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Affiliation(s)
- Tatsuhiko Sato
- Nuclear Science and Engineering Center, JAEA, 2-4 Shirakata, Naka-gun, Ibaraki, 319-1184, JAPAN
| | - Yusuke Matsuya
- Hokkaido University, N12-W5, Kitaku, Sapporo, 060-0812, JAPAN
| | - Tatsuhiko Ogawa
- JAEA, Shirakata 2-4, Tokai, Ibaraki 319-1195, Japan, Naka-gun, Ibaraki, 319-1184, JAPAN
| | - Takeshi Kai
- JAEA, 2-4 Shiraka, Tokai, Ibaraki, 319-1195, JAPAN
| | - Yuho Hirata
- Nuclear Science and Engineering Center, JAEA, 2-4 Shirakata, Naka-gun, Ibaraki, 319-1195, JAPAN
| | - Shuichi Tsuda
- JAEA, Shirakata 2-4, Tokai, Ibaraki, 319-1195, JAPAN
| | - Alessio Parisi
- Radiation Oncology, Mayo Clinic, 4500 San Pablo Rd S, Jacksonville, Florida, 32224, UNITED STATES
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Papadopoulos A, Kyriakou I, Incerti S, Santin G, Nieminen P, Daglis IA, Li W, Emfietzoglou D. Space radiation quality factor for Galactic Cosmic Rays and typical space mission scenarios using a microdosimetric approach. Radiat Environ Biophys 2023; 62:221-234. [PMID: 37062024 DOI: 10.1007/s00411-023-01023-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/25/2023] [Indexed: 05/18/2023]
Abstract
Space radiation exposure from omnipresent Galactic Cosmic Rays (GCRs) in interplanetary space poses a serious carcinogenic risk to astronauts due to the-limited or absent-protective effect of the Earth's magnetosphere and, in particular, the terrestrial atmosphere. The radiation risk is directly influenced by the quality of the radiation, i.e., its pattern of energy deposition at the micron/DNA scale. For stochastic biological effects, radiation quality is described by the quality factor, [Formula: see text], which can be defined as a function of Linear Energy Transfer (LET) or the microdosimetric lineal energy ([Formula: see text]). In the present work, the average [Formula: see text] of GCR for different mission scenarios was calculated using a modified version of the microdosimetric Theory of Dual Radiation Action (TDRA). NASA's OLTARIS platform was utilized to generate the radiation environment behind different aluminum shielding (0-30 g/cm2) for a typical mission scenario in low-earth orbit (LEO) and in deep space. The microdosimetric lineal energy spectra of ions ([Formula: see text]) in 1 μm liquid water spheres were calculated by a generalized analytical model which considers energy-loss fluctuations and δ-ray transport inside the irradiated medium. The present TDRA-based [Formula: see text]-values for the LEO and deep space missions were found to differ by up to 10% and 14% from the corresponding ICRP-based [Formula: see text]-values and up to 3% and 6% from NASA's [Formula: see text]-model. In addition, they were found to be in good agreement with the [Formula: see text]-values measured in the International Space Station (ISS) and by the Mars Science Laboratory (MSL) Radiation Assessment Detector (RAD) which represent, respectively, a LEO and deep space orbit.
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Affiliation(s)
- Alexis Papadopoulos
- Medical Physics Laboratory, Department of Medicine, University of Ioannina, 45110, Ioannina, Greece
| | - Ioanna Kyriakou
- Medical Physics Laboratory, Department of Medicine, University of Ioannina, 45110, Ioannina, Greece
| | - Sébastien Incerti
- University of Bordeaux, CNRS, LP2I, UMR 5797, F-33170, Gradignan, France
| | - Giovanni Santin
- ESA/ESTEC Space Environments and Effects Section, ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, ZH, The Netherlands
| | - Petteri Nieminen
- ESA/ESTEC Space Environments and Effects Section, ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, ZH, The Netherlands
| | - Ioannis A Daglis
- Department of Physics, National and Kapodistrian University of Athens, 15784, Athens, Greece
- Hellenic Space Center, 15231, Athens, Greece
| | - Weibo Li
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764, Neuherberg, Germany
- Federal Office for Radiation Protection (BfS), Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany
| | - Dimitris Emfietzoglou
- Medical Physics Laboratory, Department of Medicine, University of Ioannina, 45110, Ioannina, Greece.
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Barna S, Meouchi C, Resch AF, Magrin G, Georg D, Palmans H. 3D printed 2D range modulators preserve radiation quality on a microdosimetric scale in proton and carbon ion beams. Radiother Oncol 2023; 182:109525. [PMID: 36774996 DOI: 10.1016/j.radonc.2023.109525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/12/2023]
Abstract
INTRODUCTION Particle therapy using pencil beam scanning (PBS) faces large uncertain- ties related to ranges and target motion. One possibility to improve existing mitigation strategies is a 2D range modulator (2DRM). A 2DRM offers faster irradiation times by reducing the number of layers and spots needed to create a spread-out Bragg peak. We have investigated the impact of 2DRM on microdosimetric spectra measured in proton and carbon ion beams. MATERIALS AND METHODS Two 2DRMs were designed and 3D printed, one for. 124.7 MeV protons and one for 238.6 MeV/u carbon ions. Their dosimetric validation was performed using Roos and PinPoint ionization chamber and EBT3 films. Monte Carlo simulations were done using GATE. A silicon-based solid-state microdosimeter was used to collect pulse-height spectra along three depths for two irradiation modalities, PBS and a single central beam. RESULTS For both particle types, the original pin design had to be optimized via GATE simulations. The difference between the R80 of the simulated and measured depth dose curve was 0.1 mm. The microdosimetric spectra collected with the two irradiation modalities overlap well. Their mean lineal energy values differ over all positions by 5.2 % for the proton 2DRM and 2.1 % for the carbon ion 2DRM. CONCLUSION Radiation quality in terms of lineal energy was independent of the irradiation method. This supports the current approach in reference dosimetry, where the residual range is chosen as a beam quality index to select stopping power ratios.
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Affiliation(s)
- Sandra Barna
- Department of Radiation Oncology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria.
| | - Cynthia Meouchi
- Atominstitut, Technical University of Vienna, Stadionallee 2, Vienna, Austria
| | - Andreas Franz Resch
- Department of Radiation Oncology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria
| | - Giulio Magrin
- MedAustron Ion Therapy Center, Marie-Curie-Straße 5, Wiener Neustadt, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria; MedAustron Ion Therapy Center, Marie-Curie-Straße 5, Wiener Neustadt, Austria
| | - Hugo Palmans
- MedAustron Ion Therapy Center, Marie-Curie-Straße 5, Wiener Neustadt, Austria; National Physical Laboratory, Hampton Road, Teddington, United Kingdom
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Magrin G, Palmans H, Stock M, Georg D. State-of-the-art and potential of experimental microdosimetry in ion-beam therapy. Radiother Oncol 2023; 182:109586. [PMID: 36842667 DOI: 10.1016/j.radonc.2023.109586] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/28/2023]
Abstract
In radiotherapy, radiation-quality should be an expression of the biological and physical characteristics of ionizing radiation such as spatial distribution of ionization or energy deposition. Linear energy transfer (LET) and lineal energy (y) are two descriptors used to quantify the radiation quality. These two quantities are connected and exhibit similar features. In ion-beam therapy (IBT), lineal energy can be measured with microdosimeters, which are specifically designed to cope with the high fluence of particles in clinical beams, while the quantification of LET is generally based on calculations. In pre-clinical studies, microdosimetric spectra are used for the indirect determination of relative biological effectiveness (RBE), e.g., using the microdosimetric kinetic model (MKM) or biophysical response functions. In this context it is important to consider saturation effects, which occur when the highest values of y become less biologically relevant compared to the relative contribution they make to the physical dose. Recent clinical data suggests that local tumor control and normal tissue effects can be linked to macroscopic and microscopic dosimetry parameters. In particular, positive clinical outcomes have been correlated to the highest LET values in the density distribution, and there is no evident link to the saturation discussed above. A systematic collection of microdosimetric information in combination with clinical data in retrospective studies may clarify the role of radiation quality at the highest LET. In the clinical setting, microdosimetry is not widely used yet, despite its potential to be linked with LET by experimentally-determined y values. Through this connection, both play an important role in complex therapy techniques such as intensity modulated particle therapy (IMPT), LET-painting and multi-ion optimization. This review summarizes the current state of microdosimetry for IBT and its potential, as well as research and development needed to make experimental microdosimetry a mature procedure in a clinical context.
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Affiliation(s)
- Giulio Magrin
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Hugo Palmans
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; National Physical Laboratory, Teddington, UK
| | - Markus Stock
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Karl Landsteiner Universität, Krems, Austria
| | - Dietmar Georg
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Medical University of Vienna, Austria.
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Bastiaannet R, Liatsou I, F Hobbs R, Sgouros G. Large-scale in vitro microdosimetry via live cell microscopy imaging: implications for radiosensitivity and RBE evaluations in alpha-emitter radiopharmaceutical therapy. J Transl Med 2023; 21:144. [PMID: 36829143 PMCID: PMC9951424 DOI: 10.1186/s12967-023-03991-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/14/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Alpha-emitter radiopharmaceutical therapy (αRPT) has shown promising outcomes in metastatic disease. However, the short range of the alpha particles necessitates dosimetry on a near-cellular spatial scale. Current knowledge on cellular dosimetry is primarily based on in vitro experiments using cell monolayers. The goal of such experiments is to establish cell sensitivity to absorbed dose (AD). However, AD cannot be measured directly and needs to be modeled. Current models, often idealize cells as spheroids in a regular grid (geometric model), simplify binding kinetics and ignore the stochastic nature of radioactive decay. It is unclear what the impact of such simplifications is, but oversimplification results in inaccurate and non-generalizable results, which hampers the rigorous study of the underlying radiobiology. METHODS We systematically mapped out 3D cell geometries, clustering behavior, agent binding, internalization, and subcellular trafficking kinetics for a large cohort of live cells under representative experimental conditions using confocal microscopy. This allowed for realistic Monte Carlo-based (micro)dosimetry. Experimentally established surviving fractions of the HER2 + breast cancer cell line treated with a 212Pb-labelled anti-HER2 conjugate or external beam radiotherapy, anchored a rigorous statistical approach to cell sensitivity and relative biological effectiveness (RBE) estimation. All outcomes were compared to a reference geometric model, which allowed us to determine which aspects are crucial model components for the proper study of the underlying radiobiology. RESULTS In total, 567 cells were measured up to 26 h post-incubation. Realistic cell clustering had a large (2x), and cell geometry a small (16.4% difference) impact on AD, compared to the geometric model. Microdosimetry revealed that more than half of the cells do not receive any dose for most of the tested conditions, greatly impacting cell sensitivity estimates. Including these stochastic effects in the model, resulted in significantly more accurate predictions of surviving fraction and RBE (permutation test; p < .01). CONCLUSIONS This comprehensive integration of the biological and physical aspects resulted in a more accurate method of cell survival modelling in αRPT experiments. Specifically, including realistic stochastic radiation effects and cell clustering behavior is crucial to obtaining generalizable radiobiological parameters.
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Affiliation(s)
- Remco Bastiaannet
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, 1550 Orleans St, Baltimore, MD, 21287, USA.
| | - Ioanna Liatsou
- grid.21107.350000 0001 2171 9311Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, 1550 Orleans St, Baltimore, MD 21287 USA
| | - Robert F Hobbs
- grid.21107.350000 0001 2171 9311Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, 1550 Orleans St, Baltimore, MD 21287 USA
| | - George Sgouros
- grid.21107.350000 0001 2171 9311Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, 1550 Orleans St, Baltimore, MD 21287 USA
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Almhagen E, Villegas F, Tilly N, Glimelius L, Traneus E, Ahnesjö A. Modelling tissue specific RBE for different radiation qualities based on a multiscale characterization of energy deposition. Radiother Oncol 2023; 182:109539. [PMID: 36806602 DOI: 10.1016/j.radonc.2023.109539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 02/03/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
PURPOSE We present the nanoCluE model, which uses nano- and microdosimetric quantities to model RBE for protons and carbon ions. Under the hypothesis that nano- and microdosimetric quantities correlates with the generation of complex DNA double strand breakes, we wish to investigate whether an improved accuracy in predicting LQ parameters may be achieved, compared to some of the published RBE models. METHODS The model is based on experimental LQ data for protons and carbon ions. We generated a database of track structure data for a number of proton and carbon ion kinetic energies with the Geant4-DNA Monte Carlo code. These data were used to obtain both a nanodosimetric quantity and a set of microdosimetric quantities. The latter were tested with different parameterizations versus experimental LQ-data to select the variable and parametrization that yielded the best fit. RESULTS For protons, the nanoCluE model yielded, for the ratio of the linear LQ term versus the test data, a root mean square error (RMSE) of 1.57 compared to 1.31 and 1.30 for two earlier other published proton models. For carbon ions the RMSE was 2.26 compared to 3.24 and 5.24 for earlier published carbon ion models. CONCLUSION These results demonstrate the feasibility of the nanoCluE RBE model for carbon ions and protons. The increased accuracy for carbon ions as compared to two other considered models warrants further investigation.
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Hartmann GH, Menzel HG. Note on uncertainty in Monte Carlo dose calculations and its relation to microdosimetry. Z Med Phys 2022:S0939-3889(22)00133-7. [PMID: 36577627 DOI: 10.1016/j.zemedi.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE The Type A standard uncertainty in Monte Carlo (MC) dose calculations is usually determined using the "history by history" method. Its applicability is based on the assumption that the central limit theorem (CLT) can be applied such that the dispersion of repeated calculations can be modeled by a Normal distribution. The justification for this assumption, however, is not obvious. The concept of stochastic quantities used in the field of microdosimetry offers an alternative approach to assess uncertainty. This leads to a new and simple expression. METHODS The value of the MC determined absorbed dose is considered a random variable which is comparable to the stochastic quantity specific energy, z. This quantity plays an important role in microdosimetry and in the definition of the quantity absorbed dose, D. One of the main features of z is that it is itself the product of two other random variables, specifically of the mean dose contribution in a 'single event' and of the mean number of such events. The term 'single event' signifies the sum of energies imparted by all correlated particles to the matter in a given volume. The similarity between the MC calculated absorbed dose and the specific energy is used to establish the 'event by event' method for the determination of the uncertainty. MC dose calculations were performed to test and compare both methods. RESULTS It is shown that the dispersion of values obtained by MC dose calculations indeed depend on the product of the mean absorbed dose per event, and the number of events. Applying methods to obtain the variance of a product of two random variables, a simple formula for the assessment of uncertainties is obtained which is slightly different from the 'history by history' method. Interestingly, both formulas yield indistinguishable results. This finding is attributed to the large number of histories used in MC simulations. Due on the fact that the values of a MC calculated absorbed dose are the product of two approximately Normal distributions it can be demonstrated that the resulting product is also approximately normally distributed. CONCLUSIONS The event by event approach appears to be more suitable than the history by history approach because it takes into account the randomness of the number of events involved in MC dose calculations. Under the condition of large numbers of histories, however, both approaches lead to the same simple expression for the determination of uncertainty in MC dose calculations. It is suggested to replace the formula currently used by the new expression. Finally, it turned out that the concept and ideas that were developed in the field of microdosimetry already 50 years ago can be usefully applied also in MC calculations.
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Affiliation(s)
| | - Hans G Menzel
- International Commission on Radiation Units and Measurements (ICRU), Germany
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11
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Du C, Wang Y, Xue H, Gao H, Liu K, Kong X, Zhang W, Yin Y, Qiu D, Wang Y, Sun L. Research on the proximity functions of microdosimetry of low energy electrons in liquid water based on different Monte Carlo codes. Phys Med 2022; 101:120-128. [PMID: 35988482 DOI: 10.1016/j.ejmp.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/25/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The proximity function is an important index in microdosimetry for describing the spatial distribution of energy, which is closely related to the biological effects of organs or tissues in the target area. In this work, the impact of parameters, such as physic models, cut-off energy, and initial energy, on the proximity function are quantitated and compared. METHODS According to the track structure (TS) and condensed history (CH) low-energy electromagnetic models, this paper chooses a variety of Monte Carlo (Monte Carlo, MC) codes (Geant4-DNA, PHITS, and Penelope) to simulate the track structure of low-energy electrons in liquid water and evaluates the influence of the electron initial energy, cut-off energy, energy spectrum, and physical model factors on the differential proximity function. RESULTS The results show that the initial energy of electrons in the low-energy part (especially less than 1 keV) has a greater impact on the differential proximity function, and the choice of cut-off energy has a greater impact on the differential proximity function corresponding to small radius sites (generally less than 10 nm). The difference in the electronic energy spectrum has little effect on the result, and the proximity functions of different physics models show better consistency under large radius sites. CONCLUSIONS This work comprehensively compares the differential proximity functions under different codes by setting a variety of simulation conditions and has basic guiding significance for helping users simulate and analyze the deposition characteristics of microscale electrons according to the selection of an appropriate methodology and cut-off energy.
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Affiliation(s)
- ChuanSheng Du
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - YiDi Wang
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - HuiYuan Xue
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - Kun Liu
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - XiangHui Kong
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - WenYue Zhang
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - YuChen Yin
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - Dong Qiu
- State Key Laboratory of Radiation Medicine and Protection, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China; School of Public Health, Medical College of Soochow University, China
| | - YouYou Wang
- The Second Affiliated Hospital of Soochow University, China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, China; School of Radiation Medicine and Protection, Soochow University, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China.
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12
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Maxwell AWP, Mendoza HG, Sellitti MJ, Camacho JC, Deipolyi AR, Ziv E, Sofocleous CT, Yarmohammadi H, Maybody M, Humm JL, Schwartz J, Juluru K, Dunphy MP, Boas FE. Optimizing 90Y Particle Density Improves Outcomes After Radioembolization. Cardiovasc Intervent Radiol 2022; 45:958-969. [PMID: 35459960 PMCID: PMC10103908 DOI: 10.1007/s00270-022-03139-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/28/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE To determine how particle density affects dose distribution and outcomes after lobar radioembolization. METHODS Matched pairs of patients, treated with glass versus resin microspheres, were selected by propensity score matching (114 patients), in this single-institution retrospective study. For each patient, tumor and liver particle density (particles/cm3) and dose (Gy) were determined. Tumor-to-normal ratio was measured on both 99mTc-MAA SPECT/CT and post-90Y bremsstrahlung SPECT/CT. Microdosimetry simulations were used to calculate first percentile dose, which is the dose in the cold spots between microspheres. Local progression-free survival (LPFS) and overall survival were analyzed. RESULTS As more particles were delivered, doses on 90Y SPECT/CT became more uniform throughout the treatment volume: tumor and liver doses became more similar (p = 0.04), and microscopic cold spots between particles disappeared. For hypervascular tumors (tumor-to-normal ratio ≥ 2.6 on MAA scan), delivering fewer particles (< 6000 particles/cm3 treatment volume) was associated with better LPFS (p = 0.03). For less vascular tumors (tumor-to-normal ratio < 2.6), delivering more particles (≥ 6000 particles/cm3) was associated with better LPFS (p = 0.02). In matched pairs of patients, using the optimal particle density resulted in improved overall survival (11.5 vs. 6.8 months, p = 0.047), compared to using suboptimal particle density. Microdosimetry resulted in better predictions of LPFS (p = 0.03), and overall survival (p = 0.02), compared to conventional dosimetry. CONCLUSION The number of particles delivered can be chosen to maximize the tumor dose and minimize the liver dose, based on tumor vascularity. Optimizing the particle density resulted in improved LPFS and overall survival.
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Affiliation(s)
- Aaron W P Maxwell
- Department of Diagnostic Imaging, The Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Humberto G Mendoza
- Molecular Imaging and Therapy Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew J Sellitti
- Radiology Informatics, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Juan C Camacho
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Amy R Deipolyi
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Etay Ziv
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Constantinos T Sofocleous
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hooman Yarmohammadi
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Majid Maybody
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - John L Humm
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jazmin Schwartz
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Krishna Juluru
- Body Imaging Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mark P Dunphy
- Molecular Imaging and Therapy Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - F Edward Boas
- Interventional Radiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Department of Radiology, City of Hope Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA.
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13
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Moeini H, Mokari M. DNA damage and microdosimetry for carbon ions: Track structure simulations as the key to quantitative modeling of radiation-induced damage. Med Phys 2022; 49:4823-4836. [PMID: 35596669 DOI: 10.1002/mp.15711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 03/29/2022] [Accepted: 05/04/2022] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Dose distribution in carbon-ion irradiations is generally envisaged to have therapeutic advantages over protons, primarily due to the carbon-ion's comparatively higher relative biological effectiveness (RBE) in the tumor than in the encompassing healthy tissues. The objective of this work was to simulate the overall physical and chemical reactions of primary carbon ions impinging on liquid water and, as such, to investigate the DNA-damage yields in the form of strand breaks (SBs) and in connection with the expected microdosimetric quantities. MATERIALS AND METHODS Using a B-DNA model and Geant4-DNA, we simulated the primary and secondary interactions in a spherical medium of water. Subsequently, we categorized DNA damages based on their complexity utilizing the concept of μ-randomness. We assumed a threshold of 17.5 eV for a direct SB and a probability of 0.13 for an indirect SB triggered by chemical reactions of hydroxyl radicals. Microdosimetric quantities were extracted for three cylindrical volumes representing typical sub-cellular organisms. RESULTS For fully-ionized carbons of 8 to 256 MeV/u, the yield results appeared to be considerably influenced by the chemical reactions - indicating the important role of secondary electrons in inflicting damage. However, it was mostly the direct-damage spectrum that determined the overall shape of the damage spectrum. At all primary energies, it was more probable to break each DNA strand at one point - the two points being less than 10 bp apart - than to break only one strand at two random points. Unlike proton's mean-specific-energy results, which showed more sensitivity to the volume increase of the smallest cylinder than of the larger ones, carbon-ion results showed no such sensitivity. CONCLUSION The growth of the yield ratio of the single- and double-strand breaks (SSB and DSB) with the particle energy was estimated for protons to be about two times that of alphas and 92 times that of carbon ions. Unlike the proton results, which suggested significant correlations between the DSB yields and mean specific (and lineal) energies, carbon ions exhibited no such correlations. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Hossein Moeini
- Department of Physics, School of Science, Shiraz University, Shiraz, 71946-84795, Iran
| | - Mojtaba Mokari
- Department of Physics, Behbahan Khatam Alanbia University of Technology, Behbahan, 6361647189, Iran
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DeCunha JM, Villegas F, Vallières M, Torres J, Camilleri-Broët S, Enger SA. Patient-specific microdosimetry: a proof of concept. Phys Med Biol 2021; 66. [PMID: 34384070 DOI: 10.1088/1361-6560/ac1d1e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 08/12/2021] [Indexed: 11/12/2022]
Abstract
Microscopic energy deposition distributions from ionizing radiation are used to predict the biological effects of an irradiation and vary depending on biological target size. Ionizing radiation is thought to kill cells or inhibit cell cycling mainly by damaging DNA in the cell nucleus. The size of cells and nuclei depends on tissue type, cell cycle, and malignancy, all of which vary between patients. The aim of this study was to develop methods to perform patient-specific microdosimetry, that being, determining microdosimetric quantities in volumes that correspond to the sizes of cells and nuclei observed in a patient's tissue. A histopathological sample extracted from a stage I lung adenocarcinoma patient was analyzed. A pouring simulation was used to generate a three-dimensional tissue model from cell and nucleus size information determined from the histopathological sample. Microdosimetric distributions including f(y) and d(y) were determined for Co-60,Ir-192,Yb-169 and I-125 in a patient-specific model containing a distribution of cell and nucleus sizes. Fixed radius models and a summation method (where f(y) from many fixed radii models are summed) were compared to the full patient-specific model to evaluate their suitability for fast determination of patient-specific microdosimetric parameters. Fixed radius models do not provide a close approximation of the full patient-specific model y ̅_f or y ̅_d for the lower energy sources investigated, Yb-169 and I-125. The higher energy sources investigated, Co-60 and Ir-192 are less sensitive to target size variation than Yb-169 and I-125. A summation method yields the most accurate approximation of the full model d(y) for all radioisotopes investigated. A summation method allows for the computation of patient-specific microdosimetric distributions with the computing power of a personal computer. With appropriate biological inputs the microdosimetric distributions computed using these methods can yield a patient-specific relative biological effectiveness as part of a multiscale treatment planning approach.
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Affiliation(s)
- Joseph M DeCunha
- Oncology, McGill University Medical Physics Unit, Montreal, Quebec, CANADA
| | - Fernanda Villegas
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, SWEDEN
| | - Martin Vallières
- Department of Computer Science, University of Sherbrooke, Sherbrooke, Quebec, CANADA
| | - Jose Torres
- Pathology, McGill University Health Centre, 1001 Decarie Blvd, E04.4246, Montreal, Quebec, H4A 1J1, CANADA
| | - Sophie Camilleri-Broët
- Department of Pathology, McGill University Faculty of Medicine, Montreal, Quebec, CANADA
| | - Shirin A Enger
- Medical Physics Unit, McGill University, Montreal, Quebec, CANADA
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15
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Sato T, Hashimoto S, Inaniwa T, Takada K, Kumada H. Implementation of simplified stochastic microdosimetric kinetic models into PHITS for application to radiation treatment planning. Int J Radiat Biol 2021; 97:1450-1460. [PMID: 34328809 DOI: 10.1080/09553002.2021.1956003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE The stochastic microdosimetric kinetic (SMK) model is one of the most sophisticated and precise models used in the estimation of the relative biological effectiveness of carbon-ion radiotherapy (CRT) and boron neutron capture therapy (BNCT). However, because of its complicated and time-consuming calculation procedures, it is nearly impractical to directly incorporate this model into a radiation treatment-planning system. MATERIALS AND METHODS Through the introduction of Taylor expansion (TE) or fast Fourier transform (FFT), we developed two simplified SMK models and implemented them into the Particle and Heavy Ion Transport code System (PHITS). To verify the implementation, we calculated the photon isoeffective doses in a cylindrical phantom placed in the radiation fields of passive CRT and accelerator-based BNCT. RESULTS AND DISCUSSION Our calculation suggested that both TE-based and FFT-based SMK models can reproduce the data obtained from the original SMK model very well for absorbed doses approximately below 5 Gy, whereas the TE-based SMK model overestimates the original data at higher doses. In terms of computational efficiency, the TE-based SMK model is much faster than the FFT-based SMK model. CONCLUSION This study enables the instantaneous calculation of the photo isoeffective dose for CRT and BNCT, considering their cellular-scale dose heterogeneities. Treatment-planning systems that use the improved PHITS as a dose-calculation engine are under development.
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Affiliation(s)
- Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan.,Research Center for Nuclear Physics, Osaka University, Suita, Japan
| | - Shintaro Hashimoto
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Japan
| | - Taku Inaniwa
- Department of Accelerator and Medical Physics, National Institute of Quantum and Radiological Science and Technology, Chiba, Japan
| | - Kenta Takada
- Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Japan
| | - Hiroaki Kumada
- Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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Chattaraj A, Selvam TP. Microdosimetry-based relative biological effectiveness calculations for radiotherapeutic electron beams: a FLUKA-based study. Radiol Phys Technol 2021; 14:297-308. [PMID: 34216005 DOI: 10.1007/s12194-021-00627-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 11/25/2022]
Abstract
Based on FLUKA, the present study is aimed at calculating the microdosimetric distributions of electron beams (6, 12 and 18 MeV) for radiotherapy as a function of depth in water at a site-size of 1 μm using a tissue-equivalent proportional counter (TEPC). Using the calculated microdosimetric distributions, the depth-specific relative biological effectiveness (RBE) of electron beams used in radiotherapy is calculated based on the theory of dual radiation action (TDRA) and the microdosimetric kinetic model (MKM). The TDRA-based calculation shows the variation of RBE of an electron beam with the absorbed dose and depth in water. In this study, we compared the RBE values calculated based on the TDRA and MKM. The FLUKA-based microdosimetric distributions in water obtained using the pre-calculated electron fluence spectra resulted in an improvement in the computational efficiency by a factor of 110 when compared with a full simulation. Depending on the beam energy and depth of water, RBETDRA was in the range 0.67-0.78. RBEMKM at 10% survival of HSG tumor cells was 0.84, which was nearly independent of the depth and beam energy.
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Affiliation(s)
- Arghya Chattaraj
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
| | - T Palani Selvam
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India.
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Kyriakou I, Tremi I, Georgakilas AG, Emfietzoglou D. Microdosimetric investigation of the radiation quality of low-medium energy electrons using Geant4-DNA. Appl Radiat Isot 2021; 172:109654. [PMID: 33676082 DOI: 10.1016/j.apradiso.2021.109654] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 02/17/2021] [Accepted: 02/20/2021] [Indexed: 02/06/2023]
Abstract
The increasing clinical use of low-energy photon and electron sources (below few tens of keV) has raised concerns on the adequacy of the existing approximation of an energy-independent radiobiological effectiveness. In this work, the variation of the quality factor (Q) and relative biological effectiveness (RBE) of electrons over the low-medium energy range (0.1 keV-1 MeV) is examined using several microdosimetry-based Monte Carlo methodologies with input data obtained from Geant4-DNA track-structure simulations. The sensitivity of the results to the different methodologies, Geant4-DNA physics models, and target sizes is examined. Calculations of Q and RBE are based on the ICRU Report 40 recommendations, the Kellerer-Hahn approximation, the site version of the theory of dual radiation action (TDRA), the microdosimetric kinetic model (MKM) of cell survival, and the calculated yield of DNA double strand breaks (DSB). The stochastic energy deposition spectra needed as input in the above approaches have been calculated for nanometer spherical volumes using the different electron physics models of Geant4-DNA. Results are normalized at 100 keV electrons which is here considered the reference radiation. It is shown that in the energy range ~50 keV-1 MeV, the calculated Q and RBE are approximately unity (to within 1-2%) irrespective of the methodology, Geant4-DNA physics model, and target size. At lower energies, Q and RBE become energy-dependent reaching a maximum value of ~1.5-2.5 between ~200 and 700 eV. The detailed variation of Q and RBE at low energies depends mostly upon the adopted methodology and target size, and less so upon the Geant4-DNA physics model. Overall, the DSB yield predicts the highest RBE values (with RBEmax≈2.5) whereas the MKM the lowest RBE values (with RBEmax≈1.5). The ICRU Report 40, Kellerer-Hahn, and TDRA methods are in excellent agreement (to within 1-2%) over the whole energy range predicting a Qmax≈2. In conclusion, the approximation Q=RBE=1 was found to be valid only above ~50 keV whereas at lower energies both Q and RBE become strongly energy-dependent. It is envisioned that the present work will contribute towards establishing robust methodologies to determine theoretically the energy-dependence of radiation quality of individual electrons which may then be used in subsequent calculations involving practical electron and photon radiation sources.
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Affiliation(s)
- Ioanna Kyriakou
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece.
| | - Ioanna Tremi
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou, Athens, Greece
| | - Alexandros G Georgakilas
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou, Athens, Greece
| | - Dimitris Emfietzoglou
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece
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Mokari M, Moeini H, Soleimani M. Calculation of microdosimetric spectra for protons using Geant4-DNA and a μ-randomness sampling algorithm for the nanometric structures. Int J Radiat Biol 2021; 97:208-218. [PMID: 33253606 DOI: 10.1080/09553002.2021.1854488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE Through introducing stochastic quantities that can be connected to the dimensions of the microscopic structures exposed to radiations, microdosimetry is concerned with the substantive specifications of radiation quality that could help gain insight into radiation effects. Utilizing the μ-randomness method and Geant4-DNA code, we calculated microdosimetry quantities for nanometric structures in a spherical body of water irradiated with protons. To gain more insight into the effects of radiation on microscopic structures and validate the code parameters, we made a comparison between our results obtained within Geant4-DNA and results from other simulations. MATERIALS AND METHODS We calculated microdosimetric quantities through irradiating a spherical body of water of 6 μm diameter with 0.5-100 MeV protons. Microdosimetric quantities were derived for cylinders with diameter × height values of 23 × 23, 50 × 100, and 300 × 300 Å × Å, which would resemble the typical sizes of sub-cellular organisms such as the DNA, nucleosome, and chromatin fiber. We exploited the concept of μ-randomness to introduce convex bodies of random positions and directions for calculating microdosimetric quantities. We used the Geant4-DNA Monte Carlo simulation toolkit for transporting protons and secondary particles and calculating the frequency- and dose-mean lineal and specific energies in cylindrical volumes. Specifically, for same-sized cylindrical volumes, microdosimetric parameters obtained by Nikjoo et al. using the KURBUC code were used for evaluation. RESULTS For the energy range investigated, the frequency-mean lineal energy, dose-mean lineal energy, frequency-mean specific energy, and dose-mean specific energy vary within [2.34,47.06] (keV/μm), [10.40,68.55] (keV/μm), [0.04,39.38] × 106 cGy, and [0.16,90.29] × 106 cGy, respectively. Regardless of the proton energy, our specific-energy results showed higher sensitivity to volume change, for smaller cylinder volumes rather than larger ones. Regardless of both proton energy and volume of the cylinder under study, we observed a generally better agreement between our frequency-mean, than dose-mean, specific energy results and the KURBUC results. CONCLUSION Using Geant4-DNA to account for the stochastic nature of energy depositions due to physical interactions between radiation and matter, we calculated microdosimetry parameters concerning proton irradiation. By employing microdosimetry concepts in conjunction with simulation results of our previous work on radiation effects on the DNA, we pinpointed and quantified correlations between microdosimetry parameters and DNA damage. As such, for a volume with comparable mass and mean chord length to the DNA, we could observe the clear correspondence of the mean lineal and specific energy results with the double-strand-break yields of protons in Gy-1.Gbp-1.
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Affiliation(s)
- Mojtaba Mokari
- Department of Physics, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran
| | - Hossein Moeini
- Department of Physics, School of Science, Shiraz University, Shiraz, Iran
| | - Marzieh Soleimani
- Department of Physics, Isfahan University of Technology, Isfahan, Iran
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19
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DeCunha JM, Poole CM, Vallières M, Torres J, Camilleri-Broët S, Rayes RF, Spicer JD, Enger SA. Development of patient-specific 3D models from histopathological samples for applications in radiation therapy. Phys Med 2021; 81:162-169. [PMID: 33461029 DOI: 10.1016/j.ejmp.2020.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 11/16/2020] [Accepted: 12/12/2020] [Indexed: 11/17/2022] Open
Abstract
The biological effects of ionizing radiation depend on the tissue, tumor type, radiation quality, and patient-specific factors. Inter-patient variation in cell/nucleus size may influence patient-specific dose response. However, this variability in dose response is not well investigated due to lack of available cell/nucleus size data. The aim of this study was to develop methods to derive cell/nucleus size distributions from digital images of 2D histopathological samples and use them to build digital 3D models for use in cellular dosimetry. Nineteen of sixty hematoxylin and eosin stained lung adenocarcinoma samples investigated passed exclusion criterion to be analyzed in the study. A difference of gaussians blob detection algorithm was used to identify nucleus centers and quantify cell spacing. Hematoxylin content was measured to determine nucleus radius. Pouring simulations were conducted to generate one-hundred 3D models containing volumes of equivalent cell spacing and nuclei radius to those in histopathological samples. The nuclei radius distributions of non-tumoral and cancerous regions appearing in the same slide were significantly different (p < 0.01) in all samples analyzed. The median nuclear-cytoplasmic ratio was 0.36 for non-tumoral cells and 0.50 for cancerous cells. The average cellular and nucleus packing densities in the 3D models generated were 65.9% (SD: 1.5%) and 13.3% (SD: 0.3%) respectively. Software to determine cell spacing and nuclei radius from histopathological samples was developed. 3D digital tissue models containing volumes with equivalent cell spacing, nucleus radius, and packing density to cancerous tissues were generated.
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Affiliation(s)
- Joseph M DeCunha
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montréal, Québec, Canada.
| | | | - Martin Vallières
- Department of Computer Science, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - Jose Torres
- Department of Pathology, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - Sophie Camilleri-Broët
- Department of Pathology, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - Roni F Rayes
- Cancer Research Program and the LD MacLean Surgical Research Laboratories, Department of Surgery, Division of Upper GI and Thoracic Surgery, Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - Jonathan D Spicer
- Cancer Research Program and the LD MacLean Surgical Research Laboratories, Department of Surgery, Division of Upper GI and Thoracic Surgery, Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montréal, Québec, Canada; Research Institute of the McGill University Health Center, Montréal, Québec, Canada; Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
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20
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Sato T, Furuta T, Liu Y, Naka S, Nagamori S, Kanai Y, Watabe T. Individual dosimetry system for targeted alpha therapy based on PHITS coupled with microdosimetric kinetic model. EJNMMI Phys 2021; 8:4. [PMID: 33432383 PMCID: PMC7801536 DOI: 10.1186/s40658-020-00350-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/21/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND An individual dosimetry system is essential for the evaluation of precise doses in nuclear medicine. The purpose of this study was to develop a system for calculating not only absorbed doses but also EQDX(α/β) from the PET-CT images of patients for targeted alpha therapy (TAT), considering the dose dependence of the relative biological effectiveness, the dose-rate effect, and the dose heterogeneity. METHODS A general-purpose Monte Carlo particle transport code PHITS was employed as the dose calculation engine in the system, while the microdosimetric kinetic model was used for converting the absorbed dose to EQDX(α/β). PHITS input files for describing the geometry and source distribution of a patient are automatically created from PET-CT images, using newly developed modules of the radiotherapy package based on PHITS (RT-PHITS). We examined the performance of the system by calculating several organ doses using the PET-CT images of four healthy volunteers after injecting 18F-NKO-035. RESULTS The deposition energy map obtained from our system seems to be a blurred image of the corresponding PET data because annihilation γ-rays deposit their energies rather far from the source location. The calculated organ doses agree with the corresponding data obtained from OLINDA 2.0 within 20%, indicating the reliability of our developed system. Test calculations by replacing the labeled radionuclide from 18F to 211At suggest that large dose heterogeneity in a target volume is expected in TAT, resulting in a significant decrease of EQDX(α/β) for higher-activity injection. CONCLUSIONS As an extension of RT-PHITS, an individual dosimetry system for nuclear medicine was developed based on PHITS coupled with the microdosimetric kinetic model. It enables us to predict the therapeutic and side effects of TAT based on the clinical data largely available from conventional external radiotherapy.
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Affiliation(s)
- Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Ibaraki, 319-1195, Japan.
- Research Center for Nuclear Physics, Osaka University, Suita, Japan.
| | - Takuya Furuta
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Ibaraki, 319-1195, Japan
| | - Yuwei Liu
- Department of Nuclear Medicine and Tracer Kinetics, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Sadahiro Naka
- Department of Radiology, Osaka University Hospital, Suita, Japan
| | - Shushi Nagamori
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Tadashi Watabe
- Department of Nuclear Medicine and Tracer Kinetics, Graduate School of Medicine, Osaka University, Suita, Japan
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21
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Seniwal B, Mendes BM, Malano F, Pérez P, Valente M, Fonseca TCF. Monte Carlo assessment of low energy electron range in liquid water and dosimetry effects. Phys Med 2020; 80:363-372. [PMID: 33285337 DOI: 10.1016/j.ejmp.2020.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/30/2020] [Accepted: 11/07/2020] [Indexed: 11/25/2022] Open
Abstract
The effects of low energy electrons in biological tissues have proved to lead to severe damages at the cellular and sub-cellular level. It is due to an increase in the relative biological effectiveness (RBE) of these electrons with a decrease in their penetration range. That is, lower the range higher will be its RBE.Therefore, accurate determination of low energy electron range becomes a key issue for radiation dosimetry. This work reports on in-water electron tracks evaluated at low kinetic energy (1-50 keV) using isotropic mono-energetic point source approach suitably implemented by different general-purpose Monte Carlo codes. For this aim, simulations were performed using PENELOPE, EGSnrc, MCNP6, FLUKA and Geant4-DNA Monte Carlo codes to obtain the particle range, R,R90,R50. Finally, evaluation of dose point kernel (DPK), as used for internal dosimetry, was carried out as an application example. Scaled dose point kernels (sDPK) were estimated for a range of mono-energetic low energy electron sources. The non-negligible differences among the calculated sDPK using different codes were obtained for energy electrons up to 5 keV. It was also observed that differences of in-water range for low-energy electrons, due to the different general-purpose Monte Carlo codes, affected the DPKs used for dosimetry by convolution approach. Finally, the 3D dosimetry was found to be almost not affected at macroscopic clinical scale, whereas non-negligible differences appeared at the microscopic level. Hence, a thorough validation of the used sDPKs have to be performed before they could be used in applications to derive any conclusions.
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Affiliation(s)
- Baljeet Seniwal
- Departamento de Engenharia Nuclear (DEN/UFMG) & Programa de Pós-graduação em Ciências e Técnicas Nucleares (PCTN), Universidade Federal de Minas Gerais (UFMG), Av. Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Bruno M Mendes
- Centro de Desenvolvimento da Tecnologia Nuclear - CDTN/CNEN, Belo Horizonte, MG, Brasil
| | - Francisco Malano
- Departamento de Ciencias Físicas & Centro de Física e Ingeniería en Medicina (CFIM), Univesidad de La Frontera, Temuco, Chile
| | - Pedro Pérez
- Instituto de Física E. Gaviola, CONICET & Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Medina Allende esq. Haya de la Torre, Córdoba, Argentina
| | - Mauro Valente
- Instituto de Física E. Gaviola, CONICET & Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, Medina Allende esq. Haya de la Torre, Córdoba, Argentina; Centro de Física e Ingeniería en Medicina (CFIM) & Departamento de Ciencias Físicas, Univesidad de La Frontera, Temuco, Chile
| | - Telma C F Fonseca
- Departamento de Engenharia Nuclear (DEN/UFMG) & Programa de Pós-graduação em Ciências e Técnicas Nucleares (PCTN), Universidade Federal de Minas Gerais (UFMG), Av. Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil.
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22
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Tan HQ, Koh WYC, Yeo ELL, Ang KW, Poon DJJ, Lim CP, Vajandar SK, Chen CB, Ren M, Osipowicz T, Soo KC, Chua MLK, Park SY. Dosimetric uncertainties impact on cell survival curve with low energy proton. Phys Med 2020; 76:277-284. [PMID: 32738775 DOI: 10.1016/j.ejmp.2020.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 10/23/2022] Open
Abstract
There is an increasing number of radiobiological experiments being conducted with low energy protons (less than 5 MeV) for radiobiological studies due to availability of sub-millimetre focused beam. However, low energy proton has broad microdosimetric spectra which can introduce dosimetric uncertainty. In this work, we quantify the impact of this dosimetric uncertainties on the cell survival curve and how it affects the estimation of the alpha and beta parameters in the LQ formalism. Monte Carlo simulation is used to generate the microdosimetric spectra in a micrometer-sized water sphere under proton irradiation. This is modelled using radiobiological experiment set-up at the Centre of Ion Beam Application (CIBA) in National University of Singapore. Our results show that the microdosimetric spectra can introduce both systematic and random shifts in dose and cell survival; this effect is most pronounced with low energy protons. The alpha and beta uncertainties can be up to 10% and above 30%, respectively for low energy protons passing through thin cell target (about 10 microns). These uncertainties are non-negligible and show that care must be taken in using the cell survival curve and its derived parameters for radiobiological models.
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Affiliation(s)
- Hong Qi Tan
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore.
| | - Wei Yang Calvin Koh
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore
| | | | - Khong Wei Ang
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | | | - Chu Pek Lim
- Division of Medical Sciences, National Cancer Centre Singapore, Singapore; Duke-NUS Medical School, Oncology Academic Clinical Programme, Singapore
| | - Saumitra K Vajandar
- Centre for Ion Beam Application, National University of Singapore, Singapore
| | - Ce-Belle Chen
- Centre for Ion Beam Application, National University of Singapore, Singapore
| | - Minqin Ren
- Centre for Ion Beam Application, National University of Singapore, Singapore
| | - Thomas Osipowicz
- Centre for Ion Beam Application, National University of Singapore, Singapore
| | - Khee Chee Soo
- Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - Melvin Lee Kiang Chua
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore; Division of Medical Sciences, National Cancer Centre Singapore, Singapore; Duke-NUS Medical School, Oncology Academic Clinical Programme, Singapore
| | - Sung Yong Park
- Division of Radiation Oncology, National Cancer Centre Singapore, Singapore
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23
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Lund CM, Famulari G, Montgomery L, Kildea J. A microdosimetric analysis of the interactions of mono-energetic neutrons with human tissue. Phys Med 2020; 73:29-42. [PMID: 32283505 DOI: 10.1016/j.ejmp.2020.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/05/2020] [Accepted: 04/02/2020] [Indexed: 10/24/2022] Open
Abstract
Nuclear reactions induced during high-energy radiotherapy produce secondary neutrons that, due to their carcinogenic potential, constitute an important risk for the development of iatrogenic cancer. Experimental and epidemiological findings indicate a marked energy dependence of neutron relative biological effectiveness (RBE) for carcinogenesis, but little is reported on its physical basis. While the exact mechanism of radiation carcinogenesis is yet to be fully elucidated, numerical microdosimetry can be used to predict the biological consequences of a given irradiation based on its microscopic pattern of energy depositions. Building on recent studies, this work investigated the physics underlying neutron RBE by using the microdosimetric quantity dose-mean lineal energy (y‾D) as a proxy. A simulation pipeline was constructed to explicitly calculate the y‾D of radiation fields that consisted of (i) the open source Monte Carlo toolkit Geant4, (ii) its radiobiological extension Geant4-DNA, and (iii) a weighted track-sampling algorithm. This approach was used to study mono-energetic neutrons with initial kinetic energies between 1 eV and 10 MeV at multiple depths in a tissue-equivalent phantom. Spherical sampling volumes with diameters between 2 nm and 1 μm were considered. To obtain a measure of RBE, the neutron y‾D values were divided by those of 250 keV X-rays that were calculated in the same way. Qualitative agreement was found with published radiation protection factors and simulation data, allowing for the dependencies of neutron RBE on depth and energy to be discussed in the context of the neutron interaction cross sections and secondary particle distributions in human tissue.
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Affiliation(s)
- C M Lund
- Medical Physics Unit, McGill University, Montreal, QC H4A3J1, Canada.
| | - G Famulari
- Medical Physics Unit, McGill University, Montreal, QC H4A3J1, Canada
| | - L Montgomery
- Medical Physics Unit, McGill University, Montreal, QC H4A3J1, Canada
| | - J Kildea
- Medical Physics Unit, McGill University, Montreal, QC H4A3J1, Canada
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24
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Markovic VM, Stevanovic N, Nikezic D. Monte Carlo investigation of electron specific energy distribution in a single cell model. Radiat Environ Biophys 2020; 59:161-171. [PMID: 31659434 DOI: 10.1007/s00411-019-00815-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Knowledge of microdosimetric quantities of certain radionuclides is important in radio immune cancer therapies. Specific energy distribution of radionuclides, which are bound to the cell, is the microdosimetric quantity essential in the process of radionuclide selection for patient tumour treatment. The aim of this paper is to establish an applicable method to determine microdosimetric quantities for various radionuclides. The established method is based on knowledge of microdosimetric quantities of monoenergetic electrons. In this paper these quantities are determined for the single-cell model for a range of electron energies up to [Formula: see text], using the Monte Carlo transport code PENELOPE. The results show that using monoenergetic specific energies, reconstruction of the specific energy of beta-emitting radionuclides can be successfully done with very high accuracy. Microdosimetric quantities share information about the physical processes involved and give insight about energy depositions, which is of use in the procedure of radionuclide selection for a given type of therapy.
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Affiliation(s)
- V M Markovic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000, Kragujevac, Serbia.
| | - N Stevanovic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000, Kragujevac, Serbia
| | - D Nikezic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, 34000, Kragujevac, Serbia
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25
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Hofmann W, Li WB, Friedland W, Miller BW, Madas B, Bardiès M, Balásházy I. Internal microdosimetry of alpha-emitting radionuclides. Radiat Environ Biophys 2020; 59:29-62. [PMID: 31863162 PMCID: PMC7012986 DOI: 10.1007/s00411-019-00826-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 12/08/2019] [Indexed: 05/27/2023]
Abstract
At the tissue level, energy deposition in cells is determined by the microdistribution of alpha-emitting radionuclides in relation to sensitive target cells. Furthermore, the highly localized energy deposition of alpha particle tracks and the limited range of alpha particles in tissue produce a highly inhomogeneous energy deposition in traversed cell nuclei. Thus, energy deposition in cell nuclei in a given tissue is characterized by the probability of alpha particle hits and, in the case of a hit, by the energy deposited there. In classical microdosimetry, the randomness of energy deposition in cellular sites is described by a stochastic quantity, the specific energy, which approximates the macroscopic dose for a sufficiently large number of energy deposition events. Typical examples of the alpha-emitting radionuclides in internal microdosimetry are radon progeny and plutonium in the lungs, plutonium and americium in bones, and radium in targeted radionuclide therapy. Several microdosimetric approaches have been proposed to relate specific energy distributions to radiobiological effects, such as hit-related concepts, LET and track length-based models, effect-specific interpretations of specific energy distributions, such as the dual radiation action theory or the hit-size effectiveness function, and finally track structure models. Since microdosimetry characterizes only the initial step of energy deposition, microdosimetric concepts are most successful in exposure situations where biological effects are dominated by energy deposition, but not by subsequently operating biological mechanisms. Indeed, the simulation of the combined action of physical and biological factors may eventually require the application of track structure models at the nanometer scale.
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Affiliation(s)
- Werner Hofmann
- Biological Physics, Department of Chemistry and Physics of Materials, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria.
| | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
| | - Werner Friedland
- Institute of Radiation Medicine, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Brian W Miller
- Department of Radiation Oncology, School of Medicine, University of Colorado, Aurora, CO, 80045, USA
- College of Optical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Balázs Madas
- Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
| | - Manuel Bardiès
- Centre de Recherches en Cancérologie de Toulouse, UMR 1037, INSERM Université Paul Sabatier, Toulouse, France
| | - Imre Balásházy
- Environmental Physics Department, MTA Centre for Energy Research, Budapest, Hungary
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26
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Moslehi A, Ansari M, Monadi S. Microdosimetric modeling of the sensitometric curve of GafChromic films in the photon fields. Phys Med 2020; 69:170-5. [PMID: 31918369 DOI: 10.1016/j.ejmp.2019.12.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 12/01/2019] [Accepted: 12/19/2019] [Indexed: 11/20/2022] Open
Abstract
The sensitometric curve of EBT3 GafChromic film located at a depth 5 cm of RW3 water-equivalent phantom exposed to 6 MV X-rays is investigated. Variation of optical density for absorbed doses less than 2 Gy is determined by the experimental measurement together with the microdosimetric one-hit detector model. It is found that this model needs two fitting parameters, a maximum optical density and a saturation parameter. Both of them depend on the film structure as well as the photon spectrum. Meanwhile, the saturation parameter is a function of the microdosimetric single-event distribution of specific energy, i.e., f1(z). To calculate this distribution, irradiation of the films is simulated by the Geant4 toolkit. A sample of EBT3 film with 2 mm × 2 mm area is simulated. Active layer of the film is considered to contain 5000 cylindrical sensitive targets (SV) with 9.4 μm length and 1.62 μm diameter, located in random positions with different axial directions. The results obtained show that below an absorbed dose 1 Gy the maximum difference between the measured and the calculated optical densities is about 11%, while for the doses above 1 Gy the discrepancy is at most 3%. Eventually, it can be concluded that the sensitometric curve of EBT3 GafChromic film can satisfactorily be determined by the microdosimetric one-hit detector model, especially in the dose range above 1 Gy.
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27
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Vohradsky J, Guatelli S, Davis JA, Tran LT, Rosenfeld AB. Evaluation of silicon based microdosimetry for Boron Neutron Capture Therapy Quality Assurance. Phys Med 2019; 66:8-14. [PMID: 31541864 DOI: 10.1016/j.ejmp.2019.09.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 11/28/2022] Open
Abstract
The shift from reactor to accelerator based neutron production has created a renewed interested in Boron Neutron Capture Therapy (BNCT). BNCT is reliant upon the favourable uptake of 10B by tumour cells along with the interaction with neutrons to produce high LET fragments (He and Li nuclei) that deposit energy locally within the tumour cells. As with any radiation based treatment, Quality Assurance (QA) is crucial. In particular, Geant4 was used to model and optimise the geometry and packaging of Silicon on Insulator (SOI) microdosimeters for BNCT Quality Assurance purposes in view of experimental measurements at the KUR research reactor, in Japan. In this context, design optimisation pertains to the sensitive volume size and probability of neutron activation. This study has shown conclusively that whilst the materials currently used in the fabrication of silicon based microdosimeters are appropriate, there are changes with respect to the sensitive volume thickness that should be addressed to reduce the number of 'stoppers' in the microdosimeter.
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Affiliation(s)
- James Vohradsky
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
| | - Jeremy A Davis
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Linh T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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28
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Conte V, Bianchi A, Selva A, Petringa G, Cirrone GAP, Parisi A, Vanhavere F, Colautti P. Microdosimetry at the CATANA 62 MeV proton beam with a sealed miniaturized TEPC. Phys Med 2019; 64:114-122. [PMID: 31515010 DOI: 10.1016/j.ejmp.2019.06.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/13/2019] [Accepted: 06/23/2019] [Indexed: 11/15/2022] Open
Abstract
A new mini-TEPC with cylindrical sensitive volume of 0.9 mm in diameter and height, and with external diameter of 2.7 mm, has been developed to work without gas flow. With such a mini counter we have measured the physical quality of the 62 MeV therapeutic proton beam of CATANA (Catania, Italy). Measurements were performed at six precise positions along the Spread-Out Bragg Peak (SOBP): 1.4, 19.4, 24.6, 29.0, 29.7 and 30.8 mm, corresponding to positions of clinical relevance (entrance, proximal, central, and distal-edge of the SOBP) or of high lineal energy transfer (LET) increment (distal-dose drop off). Without refilling the microdosimeter with new gas, the measurements were repeated at the same positions 4 months later, in order to study the stability of the response in sealed-mode operation. From the microdosimetric spectra the frequency-mean lineal energy y-F and the dose-mean lineal energy y-D were derived and compared with average LET values calculated by means of Geant4 simulations. The comparison points out, in particular, a good agreement between microdosimetric y-D and the total dose-average LET¯d, which is the average LET of the mixed radiation field, including the contribution by nuclear reactions.
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Affiliation(s)
- V Conte
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro, Italy.
| | - A Bianchi
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro, Italy; Belgian Nuclear Research Centre, SCK·CEN, Boeretang 200, 2400 Mol, Belgium; UHasselt, Faculty of Engineering Technology, Centre for Environmental Sciences, Nuclear Technology Center, Agoralaan, 3590 Diepenbeek, Belgium
| | - A Selva
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro, Italy
| | - G Petringa
- INFN Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy
| | - G A P Cirrone
- INFN Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania, Italy
| | - A Parisi
- Belgian Nuclear Research Centre, SCK·CEN, Boeretang 200, 2400 Mol, Belgium
| | - F Vanhavere
- Belgian Nuclear Research Centre, SCK·CEN, Boeretang 200, 2400 Mol, Belgium
| | - P Colautti
- INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro, Italy
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29
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Cho IC, Chen FH, Chao TC, Tung CJ. A Monte Carlo study of bone-tissue interface microdosimeters. Appl Radiat Isot 2018; 140:193-200. [PMID: 30048920 DOI: 10.1016/j.apradiso.2018.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/28/2018] [Accepted: 07/13/2018] [Indexed: 11/26/2022]
Abstract
Radiation-induced bone diseases were frequently reported in radiotherapy patients. To study the diseases, microdosimeters were constructed with walls of A150-A150, A150-B100, B100-A150 and B100-B100 interfaces. Monte Carlo simulations of these microdosimeters were performed to determine the lineal energy spectra of an interface site at different depths in water for 230 MeV protons. Comparing these spectra with data of ICRU tissue and bone walls, better agreements were found at shallow depths for protons and delta-rays than deep depths for nuclear interactions.
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Affiliation(s)
- I-Chun Cho
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan; Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan
| | - Fang-Hsin Chen
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan; Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan
| | - Tsi-Chian Chao
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan; Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan
| | - Chuan-Jong Tung
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan; Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan.
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30
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Abstract
BACKGROUND While alpha microdosimetry dates back a couple of decades, the effects of localized energy deposition of alpha particles are often still unclear since few comparative studies have been performed. Most modern alpha microdosimetry studies rely for large parts on simulations, which negatively impacts both the simplicity of the calculations and the reliability of the results. A novel microdosimetry method based on the Fluorescent Nuclear Track Detector, a versatile tool that can measure individual alpha particles at sub-micron resolution, yielding accurate energy, fluence and dose rate measurements, was introduced to address these issues. METHODS Both the detectors and U87 glioblastoma cell cultures were irradiated using an external Am241 alpha source. The alpha particle tracks measured with a Fluorescent Nuclear Track Detector were used together with high resolution 3D cell geometries images to calculate the nucleus dose distribution in the U87 glioblastoma cells. The experimentally obtained microdosimetry parameters were thereafter applied to simulations of 3D U87 cells cultures (spheroids) with various spatial distributions of isotopes to evaluate the effect of the nucleus dose distribution on the expected cell survival. RESULTS The new experimental method showed good agreement with the analytically derived nucleus dose distributions. Small differences (< 5%) in the relative effectiveness were found for isotopes in the cytoplasm and on the cell membrane versus external irradiation, while isotopes located in the nucleus or on the nuclear membrane showed a substantial increase in relative effectiveness (33 - 51%). CONCLUSIONS The ease-of-use, good accuracy and use of experimentally derived characteristics of the radiation field make this method superior to conventional simulation-based microdosimetry studies. Considering the uncertainties found in alpha radionuclide carriers in-vivo and in-vitro, together with the large contributions from the relative biological effectiveness and the oxygen enhancement ratio, it is expected that only carriers penetrating or surrounding the cell nucleus will substantially benefit from microdosimetry.
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Affiliation(s)
- J. J. M. Kouwenberg
- Radiation, Science & Technology, Delft University of Technology, Mekelweg 15, Delft, The Netherlands
| | - H. T. Wolterbeek
- Radiation, Science & Technology, Delft University of Technology, Mekelweg 15, Delft, The Netherlands
| | - A. G. Denkova
- Radiation, Science & Technology, Delft University of Technology, Mekelweg 15, Delft, The Netherlands
| | - A. J. J. Bos
- Radiation, Science & Technology, Delft University of Technology, Mekelweg 15, Delft, The Netherlands
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31
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Lin Y, Yuan Y, Fang F, Tan Z. A study of electric field distribution in Benjamin type proportional counter using finite element method. Appl Radiat Isot 2018; 135:142-146. [PMID: 29413829 DOI: 10.1016/j.apradiso.2018.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/06/2017] [Accepted: 01/12/2018] [Indexed: 11/29/2022]
Abstract
Tissue equivalent proportional counters (TEPCs) are commonly based on the Benjamin type of concept. Initially the electric field is optimized by pulse height measurement methods and only one optimum solution was established at that time. In this paper, the electric field distribution is analyzed and optimized using a three-dimensional finite element method. The calculations show that the characteristics of the radial electric field distribution of this type of counters can be equated to cylindrical counters using a pair of appropriate field shaping electrode. Furthermore, the paper analyzes the axial electric field distribution and the possibility of achieving a uniform electric field along its anode while reducing the size of Benjamin type proportional counter design down to 1/10 of currently feasible values with respect to the thinnest available anode wire diameters.
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Affiliation(s)
- Ye Lin
- Key Laboratory of Applied Nuclear Techniques in Geosciences Sichuan, Chengdu University of Technology, Chengdu 610059, China; Helmholtz-Institut Jena, 07731 Jena, Germany; Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany
| | - Yonggang Yuan
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
| | - Fang Fang
- Key Laboratory of Applied Nuclear Techniques in Geosciences Sichuan, Chengdu University of Technology, Chengdu 610059, China
| | - Zhaoyi Tan
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
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32
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Mazza A, Newhauser W, Pittman S, Halloran A, Maggi P, Tran L, Gila B, Rosenfeld A, Ziegler J. Cell-shaped silicon-on-insulator microdosimeters: characterization and response to 239PuBe irradiations. Australas Phys Eng Sci Med 2017; 40:667-673. [PMID: 28887797 DOI: 10.1007/s13246-017-0576-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/31/2017] [Indexed: 11/30/2022]
Abstract
This work tested the feasibility of a silicon-on-insulator microdosimeter, which mimics the size and shape of specific cells within the human body, to determine dose equivalent from neutron irradiation. The microdosimeters were analyzed in terms of their basic diode characteristics, i.e., leakage current as a function of bias voltage. Lineal energy spectra were acquired using two different converter layers placed atop the microdosimeter: a tissue-substitute converter made from high-density polyethylene, and a boron converter consisting of epoxy coated with boron powder. The spectra were then converted into absorbed dose and dose equivalent. Experimental results were compared to Monte Carlo simulations of the neutron irradiations, revealing good agreement. Uncertainty in the dose equivalent determinations was 7.5% when using the cell-shaped microdosimeter with the tissue-substitute converter and 13.1% when using the boron converter. This work confirmed that the SOI approach to cell-mimicking microdosimetry is feasible.
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Affiliation(s)
- Anthony Mazza
- Medical Physics and Health Physics Program, Department of Physics and Astronomy, Louisiana State University, 439 Nicholson Hall, Tower Dr., Baton Rouge, LA, 70803-4001, USA. .,Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, LA, USA.
| | - Wayne Newhauser
- Medical Physics and Health Physics Program, Department of Physics and Astronomy, Louisiana State University, 439 Nicholson Hall, Tower Dr., Baton Rouge, LA, 70803-4001, USA.,Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, LA, USA
| | - Stephen Pittman
- Medical Physics and Health Physics Program, Department of Physics and Astronomy, Louisiana State University, 439 Nicholson Hall, Tower Dr., Baton Rouge, LA, 70803-4001, USA
| | - Andrew Halloran
- Medical Physics and Health Physics Program, Department of Physics and Astronomy, Louisiana State University, 439 Nicholson Hall, Tower Dr., Baton Rouge, LA, 70803-4001, USA
| | - Paul Maggi
- Medical Physics and Health Physics Program, Department of Physics and Astronomy, Louisiana State University, 439 Nicholson Hall, Tower Dr., Baton Rouge, LA, 70803-4001, USA
| | - Linh Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Brent Gila
- Nanoscale Research Facility, University of Florida, Gainesville, FL, USA
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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33
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Denzi A, Della Valle E, Apollonio F, Breton M, Mir LM, Liberti M. Exploring the Applicability of Nano-Poration for Remote Control in Smart Drug Delivery Systems. J Membr Biol 2017; 250:31-40. [PMID: 27561639 DOI: 10.1007/s00232-016-9922-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 08/16/2016] [Indexed: 12/25/2022]
Abstract
Smart drug delivery systems represent an interesting tool to significantly improve the efficiency and the precision in the treatment of a broad category of diseases. In this context, a drug delivery mediated by nanosecond pulsed electric fields seems a promising technique, allowing for a controlled release and uptake of drugs by the synergy between the electropulsation and nanocarriers with encapsulated drugs. The main concern about the use of electroporation for drug delivery applications is the difference in dimension between the liposome (nanometer range) and the cell (micrometer range). The choice of liposome dimension is not trivial. Liposomes larger than 500 nm of diameter could be recognized as pathogen agents by the immune system, while liposomes of smaller size would require external electric field of high amplitudes for the membrane electroporation that could compromise the cell viability. The aim of this work is to theoretically study the possibility of a simultaneous cell and liposomes electroporation. The numerical simulations reported the possibility to electroporate the cell and a significant percentage of liposomes with comparable values of external electric field, when a 12 nsPEF is used.
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34
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Denzi A, Camera F, Merla C, Benassi B, Consales C, Paffi A, Apollonio F, Liberti M. A Microdosimetric Study of Electropulsation on Multiple Realistically Shaped Cells: Effect of Neighbours. J Membr Biol 2016; 249:691-701. [PMID: 27318672 DOI: 10.1007/s00232-016-9912-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 06/08/2016] [Indexed: 10/21/2022]
Abstract
Over the past decades, the effects of ultrashort-pulsed electric fields have been used to investigate their action in many medical applications (e.g. cancer, gene electrotransfer, drug delivery, electrofusion). Promising aspects of these pulses has led to several in vitro and in vivo experiments to clarify their action. Since the basic mechanisms of these pulses have not yet been fully clarified, scientific interest has focused on the development of numerical models at different levels of complexity: atomic (molecular dynamic simulations), microscopic (microdosimetry) and macroscopic (dosimetry). The aim of this work is to demonstrate that, in order to predict results at the cellular level, an accurate microdosimetry model is needed using a realistic cell shape, and with their position and packaging (cell density) characterised inside the medium.
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Affiliation(s)
- Agnese Denzi
- Center for Life Nano Science at Sapienza, Istituto Italiano di Tecnologia, Rome, Italy.,Department of Information Engineering, Electronics and Telecommunication (DIET), Italian Inter-University Centre of Electromagnetic Fields and Bio-Systems (ICEmB), University of Rome "La Sapienza", 00184, Rome, Italy
| | - Francesca Camera
- Department of Information Engineering, Electronics and Telecommunication (DIET), Italian Inter-University Centre of Electromagnetic Fields and Bio-Systems (ICEmB), University of Rome "La Sapienza", 00184, Rome, Italy
| | - Caterina Merla
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, 00123, Rome, Italy.,Vectorology and Anticancer Therapies, UMR 8203, CNRS, Gustave Roussy, Univ. Paris-Sud, Université Paris-Saclay, 94805, Villejuif, France
| | - Barbara Benassi
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, 00123, Rome, Italy
| | - Claudia Consales
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, 00123, Rome, Italy
| | - Alessandra Paffi
- Department of Information Engineering, Electronics and Telecommunication (DIET), Italian Inter-University Centre of Electromagnetic Fields and Bio-Systems (ICEmB), University of Rome "La Sapienza", 00184, Rome, Italy
| | - Francesca Apollonio
- Department of Information Engineering, Electronics and Telecommunication (DIET), Italian Inter-University Centre of Electromagnetic Fields and Bio-Systems (ICEmB), University of Rome "La Sapienza", 00184, Rome, Italy
| | - Micaela Liberti
- Department of Information Engineering, Electronics and Telecommunication (DIET), Italian Inter-University Centre of Electromagnetic Fields and Bio-Systems (ICEmB), University of Rome "La Sapienza", 00184, Rome, Italy.
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35
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Semsarha F, Raisali G, Goliaei B, Khalafi H. Microdosimetry of DNA conformations: relation between direct effect of (60)Co gamma rays and topology of DNA geometrical models in the calculation of A-, B- and Z-DNA radiation-induced damage yields. Radiat Environ Biophys 2016; 55:243-254. [PMID: 26984469 DOI: 10.1007/s00411-016-0644-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/02/2016] [Indexed: 06/05/2023]
Abstract
In order to obtain the energy deposition pattern of ionizing radiation in the nanometric scale of genetic material and to investigate the different sensitivities of the DNA conformations, direct effects of (60)Co gamma rays on the three A, B and Z conformations of DNA have been studied. For this purpose, single-strand breaks (SSB), double-strand breaks (DSB), base damage (BD), hit probabilities and three microdosimetry quantities (imparted energy, mean chord length and lineal energy) in the mentioned DNA conformations have been calculated and compared by using GEometry ANd Tracking 4 (Geant4) toolkit. The results show that A-, B- and Z-DNA conformations have the highest yields of DSB (1.2 Gy(-1) Gbp(-1)), SSB (25.2 Gy(-1) Gbp(-1)) and BD (4.81 Gy(-1) Gbp(-1)), respectively. Based on the investigation of direct effects of radiation, it can be concluded that the DSB yield is largely correlated to the topological characteristics of DNA models, although the SSB yield is not. Moreover, according to the comparative results of the present study, a reliable candidate parameter for describing the relationship between DNA damage yields and geometry of DNA models in the theoretical radiation biology research studies would be the mean chord length (4 V/S) of the models.
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Affiliation(s)
- Farid Semsarha
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box: 11365-3486, Tehran, Iran
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran, Iran
| | - Gholamreza Raisali
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box: 11365-3486, Tehran, Iran.
| | - Bahram Goliaei
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran, Iran
| | - Hossein Khalafi
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box: 11365-3486, Tehran, Iran
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36
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Abstract
AIM to present the most important aspects of Microdosimetry, a research field in radiation biophysics. BACKGROUND microdosimetry is the branch of radiation biophysics that systematically studies the spatial, temporal and spectral aspects of the stochastic nature of the energy deposition processes in microscopic structures. MATERIALS AND METHODS we briefly review its history, the people, the formalism and the theories and devices that allowed researchers to begin to understand the true nature of radiation action on living matter. RESULTS AND CONCLUSIONS we outline some of its applications, especially to Boron Neutron Capture Therapy, attempting to explain the biological effectiveness of the boron thermal neutron capture reaction.
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Affiliation(s)
- Gustavo A. Santa Cruz
- Departamento Coordinación BNCT, Comisión Nacional de Energía Atómica (CNEA), Argentina
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37
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Cunha M, Testa E, Komova OV, Nasonova EA, Mel'nikova LA, Shmakova NL, Beuve M. Modeling cell response to low doses of photon irradiation--Part 1: on the origin of fluctuations. Radiat Environ Biophys 2016; 55:19-30. [PMID: 26590033 DOI: 10.1007/s00411-015-0621-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 10/11/2015] [Indexed: 06/05/2023]
Abstract
Intra- and inter-individual variability is a well-known aspect of biological responses of cells observed at low doses of radiation, whichever the phenomenon considered (adaptive response, bystander effects, genomic instability, etc.). There is growing evidence that low-dose phenomena are related to cell mechanisms other than DNA damage and misrepair, meaning that other cellular structures may play a crucial role. Therefore, in this study, a series of calculations at low doses was carried out to study the distribution of specific energies from different irradiation doses (3, 10 and 30 cGy) in targets of different sizes (0.1, 1 and 10 μm) corresponding to the dimensions of different cell structures. The results obtained show a strong dependence of the probability distributions of specific energies on the target size: targets with dimensions comparable to those of the cell show a Gaussian-like distribution, whereas very small targets are very likely to not be hit. A statistical analysis showed that the level of fluctuations in the fraction of aberrant cells is only related to the fraction of aberrant cells and the number of irradiated cells, regardless of, for instance, the heterogeneity in cell response.
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Affiliation(s)
- Micaela Cunha
- Université de Lyon, 69622, Lyon, France
- Université de Lyon 1, Villeurbanne, France
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
| | - Etienne Testa
- Université de Lyon, 69622, Lyon, France
- Université de Lyon 1, Villeurbanne, France
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
| | - Olga V Komova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Elena A Nasonova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Larisa A Mel'nikova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Nina L Shmakova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Michaël Beuve
- Université de Lyon, 69622, Lyon, France.
- Université de Lyon 1, Villeurbanne, France.
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France.
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38
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Cunha M, Testa E, Komova OV, Nasonova EA, Mel'nikova LA, Shmakova NL, Beuve M. Modeling cell response to low doses of photon irradiation: Part 2--application to radiation-induced chromosomal aberrations in human carcinoma cells. Radiat Environ Biophys 2016; 55:31-40. [PMID: 26708100 DOI: 10.1007/s00411-015-0622-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/11/2015] [Indexed: 06/05/2023]
Abstract
The biological phenomena observed at low doses of ionizing radiation (adaptive response, bystander effects, genomic instability, etc.) are still not well understood. While at high irradiation doses, cellular death may be directly linked to DNA damage, at low doses, other cellular structures may be involved in what are known as non-(DNA)-targeted effects. Mitochondria, in particular, may play a crucial role through their participation in a signaling network involving oxygen/nitrogen radical species. According to the size of the implicated organelles, the fluctuations in the energy deposited into these target structures may impact considerably the response of cells to low doses of ionizing irradiation. Based on a recent simulation of these fluctuations, a theoretical framework was established to have further insight into cell responses to low doses of photon irradiation, namely the triggering of radioresistance mechanisms by energy deposition into specific targets. Three versions of a model are considered depending on the target size and on the number of targets that need to be activated by energy deposition to trigger radioresistance mechanisms. These model versions are applied to the fraction of radiation-induced chromosomal aberrations measured at low doses in human carcinoma cells (CAL51). For this cell line, it was found in the present study that the mechanisms of radioresistance could not be triggered by the activation of a single small target (nanometric size, 100 nm), but could instead be triggered by the activation of a large target (micrometric, 10 μm) or by the activation of a great number of small targets. The mitochondria network, viewed either as a large target or as a set of small units, might be concerned by these low-dose effects.
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Affiliation(s)
- Micaela Cunha
- Université de Lyon, 69622, Lyon, France
- Université de Lyon 1, Villeurbanne, France
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
| | - Etienne Testa
- Université de Lyon, 69622, Lyon, France
- Université de Lyon 1, Villeurbanne, France
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
| | - Olga V Komova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Elena A Nasonova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Larisa A Mel'nikova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Nina L Shmakova
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
| | - Michaël Beuve
- Université de Lyon, 69622, Lyon, France.
- Université de Lyon 1, Villeurbanne, France.
- CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France.
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39
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Colautti P, Moro D, Chiriotti S, Conte V, Evangelista L, Altieri S, Bortolussi S, Protti N, Postuma I. Microdosimetric measurements in the thermal neutron irradiation facility of LENA reactor. Appl Radiat Isot 2014; 88:147-52. [PMID: 24508176 DOI: 10.1016/j.apradiso.2014.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/09/2014] [Accepted: 01/09/2014] [Indexed: 11/20/2022]
Abstract
A twin TEPC with electric-field guard tubes has been constructed to be used to characterize the BNCT field of the irradiation facility of LENA reactor. One of the two mini TEPC was doped with 50ppm of (10)B in order to simulate the BNC events occurring in BNCT. By properly processing the two microdosimetric spectra, the gamma, neutron and BNC spectral components can be derived with good precision (~6%). However, direct measurements of (10)B in some doped plastic samples, which were used for constructing the cathode walls, point out the scarce accuracy of the nominal (10)B concentration value. The influence of the Boral(®) door, which closes the irradiation channel, has been measured. The gamma dose increases significantly (+51%) when the Boral(®) door is closed. The crypt-cell-regeneration weighting function has been used to measure the quality, namely the RBEµ value, of the radiation field in different conditions. The measured RBEµ values are only partially consistent with the RBE values of other BNCT facilities.
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Affiliation(s)
- P Colautti
- INFN, Laboratori Nazionali di Legnaro, viale dell׳Università 2, I-35020 Legnaro, PD, Italy.
| | - D Moro
- INFN, Laboratori Nazionali di Legnaro, viale dell׳Università 2, I-35020 Legnaro, PD, Italy
| | - S Chiriotti
- INFN, Laboratori Nazionali di Legnaro, viale dell׳Università 2, I-35020 Legnaro, PD, Italy; SCK.CEN, Boeretang 200, B-2400 Mol, Belgium
| | - V Conte
- INFN, Laboratori Nazionali di Legnaro, viale dell׳Università 2, I-35020 Legnaro, PD, Italy
| | - L Evangelista
- INFN, Laboratori Nazionali di Legnaro, viale dell׳Università 2, I-35020 Legnaro, PD, Italy; Radiotherapy and Nuclear Medicine Unit, Istituto Oncologico Veneto, Padova, via Gattamelata 64, I-35128 Padova, Italy
| | - S Altieri
- Department of Physics, University of Pavia, via Bassi 6, I-27100 Pavia, Italy; INFN, Section of Pavia, via Bassi 6, I-7100 Pavia, Italy
| | - S Bortolussi
- Department of Physics, University of Pavia, via Bassi 6, I-27100 Pavia, Italy; INFN, Section of Pavia, via Bassi 6, I-7100 Pavia, Italy
| | - N Protti
- Department of Physics, University of Pavia, via Bassi 6, I-27100 Pavia, Italy; INFN, Section of Pavia, via Bassi 6, I-7100 Pavia, Italy
| | - I Postuma
- Department of Physics, University of Pavia, via Bassi 6, I-27100 Pavia, Italy; INFN, Section of Pavia, via Bassi 6, I-7100 Pavia, Italy
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40
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Kalantzis G, Tachibana H. Accelerated event-by-event Monte Carlo microdosimetric calculations of electrons and protons tracks on a multi-core CPU and a CUDA-enabled GPU. Comput Methods Programs Biomed 2013; 113:116-125. [PMID: 24113420 DOI: 10.1016/j.cmpb.2013.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 06/02/2023]
Abstract
For microdosimetric calculations event-by-event Monte Carlo (MC) methods are considered the most accurate. The main shortcoming of those methods is the extensive requirement for computational time. In this work we present an event-by-event MC code of low projectile energy electron and proton tracks for accelerated microdosimetric MC simulations on a graphic processing unit (GPU). Additionally, a hybrid implementation scheme was realized by employing OpenMP and CUDA in such a way that both GPU and multi-core CPU were utilized simultaneously. The two implementation schemes have been tested and compared with the sequential single threaded MC code on the CPU. Performance comparison was established on the speed-up for a set of benchmarking cases of electron and proton tracks. A maximum speedup of 67.2 was achieved for the GPU-based MC code, while a further improvement of the speedup up to 20% was achieved for the hybrid approach. The results indicate the capability of our CPU-GPU implementation for accelerated MC microdosimetric calculations of both electron and proton tracks without loss of accuracy.
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Affiliation(s)
- Georgios Kalantzis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, United States.
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41
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Kase Y, Yamashita W, Matsufuji N, Takada K, Sakae T, Furusawa Y, Yamashita H, Murayama S. Microdosimetric calculation of relative biological effectiveness for design of therapeutic proton beams. J Radiat Res 2013; 54:485-93. [PMID: 23179376 PMCID: PMC3650736 DOI: 10.1093/jrr/rrs110] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The authors attempt to establish the relative biological effectiveness (RBE) calculation for designing therapeutic proton beams on the basis of microdosimetry. The tissue-equivalent proportional counter (TEPC) was used to measure microdosimetric lineal energy spectra for proton beams at various depths in a water phantom. An RBE-weighted absorbed dose is defined as an absorbed dose multiplied by an RBE for cell death of human salivary gland (HSG) tumor cells in this study. The RBE values were calculated by a modified microdosimetric kinetic model using the biological parameters for HSG tumor cells. The calculated RBE distributions showed a gradual increase to about 1cm short of a beam range and a steep increase around the beam range for both the mono-energetic and spread-out Bragg peak (SOBP) proton beams. The calculated RBE values were partially compared with a biological experiment in which the HSG tumor cells were irradiated by the SOBP beam except around the distal end. The RBE-weighted absorbed dose distribution for the SOBP beam was derived from the measured spectra for the mono-energetic beam by a mixing calculation, and it was confirmed that it agreed well with that directly derived from the microdosimetric spectra measured in the SOBP beam. The absorbed dose distributions to planarize the RBE-weighted absorbed dose were calculated in consideration of the RBE dependence on the prescribed absorbed dose and cellular radio-sensitivity. The results show that the microdosimetric measurement for the mono-energetic proton beam is also useful for designing RBE-weighted absorbed dose distributions for range-modulated proton beams.
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Affiliation(s)
- Yuki Kase
- Proton Therapy Division, Shizuoka Cancer Center Research Institute, 1007, Shimonagakubo, Nagaizumi-cho, Shizuoka 411-8777, Japan.
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