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Mein S, Kopp B, Tessonnier T, Liermann J, Abdollahi A, Debus J, Haberer T, Mairani A. Spot-scanning hadron arc (SHArc) therapy: A proof of concept using single and multi-ion strategies with helium, carbon, oxygen and neon ions. Med Phys 2022; 49:6082-6097. [PMID: 35717613 DOI: 10.1002/mp.15800] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To present particle arc therapy treatments using single and multi-ion therapy optimization strategies with helium (4 He), carbon (12 C), oxygen (16 O) and neon (20 Ne) ion beams. METHODS AND MATERIALS An optimization procedure and workflow were devised for spot-scanning hadron arc therapy (SHArc) treatment planning in the PRECISE (PaRticle thErapy using single and Combined Ion optimization StratEgies) treatment planning system (TPS). Physical and biological beam models were developed for helium, carbon, oxygen and neon ions via FLUKA MC simulation. SHArc treatments were optimized using both single ion (12 C, 16 O, or 20 Ne) and multi-ion therapy (16 O+4 He or 20 Ne+4 He) applying variable relative biological effectiveness (RBE) modeling using a modified microdosimetric kinetic model (mMKM) with (α/β)x values of 2Gy, 5Gy and 3.1Gy respectively, for glioblastoma, pancreatic adenocarcinoma, and prostate adenocarcinoma patient cases. Dose, effective dose, linear energy transfer (LET) and RBE were computed with the GPU-accelerated dose engine FRoG and dosimetric/biophysical attributes were evaluated in the context of conventional particle and photon-based therapies (e.g., volumetric modulated arc therapy [VMAT]). RESULTS All SHArc plans met the target optimization goals (3GyRBE) and demonstrated increased target conformity and substantially lower low-dose bath to surrounding normal tissues than VMAT. SHArc plans using a single ion species (12 C, 16 O, or 20 Ne) exhibited favorable LET distributions with the highest-LET components centralized in the target volume, with values ranging from ∼80-170keV/μm, ∼130-220keV/μm and ∼180-350keV/μm, for 12 C, 16 O, or 20 Ne, respectively, exceeding mean target LET of conventional particle therapy (12 C:∼60, 16 O:∼78 20 Ne:∼100 keV/μm). Multi-ion therapy with SHArc delivery (SHArcMIT ) provided a similar level of target LET enhancement as SHArc compared to conventional planning, however, with additional benefits of homogenous physical dose and RBE distributions. CONCLUSION Here, we demonstrate that arc delivery of light and heavy ion beams, using either a single ion species (12 C, 16 O, or 20 Ne) or combining two ions in a single fraction (16 O+4 He or 20 Ne+4 He), affords enhanced physical and biological distributions (e.g., LET) compared with conventional delivery with photons or particle beams. SHArc marks the first single and multi-ion arc therapy treatment optimization approach using light and heavy ions. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Stewart Mein
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, 69120, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany and German Cancer Consortium (DKTK), Heidelberg, 69120, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Benedikt Kopp
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany
| | - Thomas Tessonnier
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany
| | - Jakob Liermann
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, 69120, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany and German Cancer Consortium (DKTK), Heidelberg, 69120, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Amir Abdollahi
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, 69120, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany and German Cancer Consortium (DKTK), Heidelberg, 69120, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Jürgen Debus
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, 69120, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany and German Cancer Consortium (DKTK), Heidelberg, 69120, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Thomas Haberer
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany
| | - Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, 69120, Germany.,Division of Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, 69120, Germany.,National Centre of Oncological Hadrontherapy (CNAO), Medical Physics, Pavia, 27100, Italy
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Parisi A, Furutani KM, Beltran CJ. On the calculation of the relative biological effectiveness of ion radiation therapy using a biological weighting function, the microdosimetric kinetic model (MKM) and subsequent corrections (non-Poisson MKM and modified MKM). Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5fdf] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/22/2022] [Indexed: 12/31/2022]
Abstract
Abstract
Objective. To investigate similarities and differences in the formalism, processing, and the results of relative biological effectiveness (RBE) calculations with a biological weighting function (BWF), the microdosimetric kinetic model (MKM) and subsequent modifications (non-Poisson MKM, modified MKM). This includes: (a) the extension of the V79-RBE10% BWF to model the RBE for other clonogenic survival levels; (b) a novel implementation of MKMs as weighting functions; (c) a benchmark against Chinese Hamster lung fibroblast (V79) in vitro data; (d) a study on the effect of pre- or post- processing the average biophysical quantities used for the RBE calculations; (e) a possible modification of the modified MKM parameters to improve the model accuracy at high linear energy transfer (LET). Methodology. Lineal energy spectra were simulated for two spherical targets (diameter = 0.464 or 1.0 μm) using PHITS for 1H, 4He, 12C, 20Ne, 40Ar, 56Fe and 132Xe ions. The results of the in silico calculations were compared with published in vitro data. Main results. All models appear to underestimate the RBE
α
of hydrogen ions. All MKMs generally overestimate the RBE50%, RBE10% and RBE1% for ions with an LET greater than ∼200 keV μm−1. This overestimation is greater for small surviving fractions and is likely due to the assumption of a radiation-independent quadratic term of clonogenic survival (ß). The overall RBE trends seem to be best described by the novel ‘post-processing average’ implementation of the non-Poisson MKM. In case of calculations with the non-Poisson MKM, pre- or post- processing the average biophysical quantities affects the computed RBE values significantly. Significance. This study presents a systematic analysis of the formalism and results of widely used microdosimetric models of clonogenic survival for ions relevant for cancer particle therapy and space radiation protection. Points for improvements were highlighted and will contribute to the development of upgraded biophysical models.
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Silicon 3D Microdosimeters for Advanced Quality Assurance in Particle Therapy. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app12010328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Centre for Medical Radiation Physics introduced the concept of Silicon On Insulator (SOI) microdosimeters with 3-Dimensional (3D) cylindrical sensitive volumes (SVs) mimicking the dimensions of cells in an array. Several designs of high-definition 3D SVs fabricated using 3D MEMS technology were implemented. 3D SVs were fabricated in different sizes and configurations with diameters between 18 and 30 µm, thicknesses of 2–50 µm and at a pitch of 50 µm in matrices with volumes of 20 × 20 and 50 × 50. SVs were segmented into sub-arrays to reduce capacitance and avoid pile up in high-dose rate pencil beam scanning applications. Detailed TCAD simulations and charge collection studies in individual SVs have been performed. The microdosimetry probe (MicroPlus) is composed of the silicon microdosimeter and low-noise front–end readout electronics housed in a PMMA waterproof sheath that allows measurements of lineal energies as low as 0.4 keV/µm in water or PMMA. Microdosimetric quantities measured with SOI microdosimeters and the MicroPlus probe were used to evaluate the relative biological effectiveness (RBE) of heavy ions and protons delivered by pencil-beam scanning and passive scattering systems in different particle therapy centres. The 3D detectors and MicroPlus probe developed for microdosimetry have the potential to provide confidence in the delivery of RBE optimized particle therapy when introduced into routine clinical practice.
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Golshani M, Azadegan B, Mowlavi AA. Microdosimetry calculations and estimation of the relative biological effectiveness of the low-energy electrons released during Gd neutron capture reaction. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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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] [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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Kim H, Sung W, Ye SJ. Microdosimetric-Kinetic Model for Radio-enhancement of Gold Nanoparticles: Comparison with LEM. Radiat Res 2021; 195:293-300. [PMID: 33400779 DOI: 10.1667/rade-20-00223.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/14/2020] [Indexed: 11/03/2022]
Abstract
Numerous studies have strongly supported the application of gold nanoparticles (GNPs) as radio-enhanced agents. In our previous study, the local effect model (LEM I) was adopted to predict the cell survival for MDA-MB-231 cells exposed to 150 kVp X rays after 500 µg/ml GNPs treatment. However, microdosimetric quantities could not be obtained, which were correlated with biological effects on cells. Thus, we developed microdosimetric kinetic model (MKM) for GNP radio-enhancement (GNP-MKM), which uses the microdosimetric quantities such as dose-mean lineal energy with subcellular domain size. Using the Monte Carlo simulation tool Geant4, we estimated the dose-mean lineal energy with secondary radiations from GNPs and absorbed dose in the nucleus. The variations in MKM parameters for different domain sizes, and GNP concentrations, were calculated to compare the survival fractions predicted by both models. With a domain radius of 500 nm and a threshold dose of 20 Gy, the sensitizer enhancement ratio predicted by GNP-MKM and GNP-LEM was 1.41 and 1.29, respectively. The GNP-MKM predictions were much more strongly dependent on the domain size than were the GNP-LEM on the threshold dose. These findings provide another method to predict survival fraction for the GNP radio-enhancement.
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Affiliation(s)
- Hyejin Kim
- Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
| | - Wonmo Sung
- Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.,Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Sung-Joon Ye
- Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.,Robotics Research Laboratory for Extreme Environment, Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Korea
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7
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Parisi A, Olko P, Swakoń J, Horwacik T, Jabłoński H, Malinowski L, Nowak T, Struelens L, Vanhavere F. Modeling the radiation-induced cell death in a therapeutic proton beam using thermoluminescent detectors and radiation transport simulations. ACTA ACUST UNITED AC 2020; 65:015008. [DOI: 10.1088/1361-6560/ab491f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Hirano Y, Kodaira S, Souda H, Osaki K, Torikoshi M. Estimations of relative biological effectiveness of secondary fragments in carbon ion irradiation of water using CR‐39 plastic detector and microdosimetric kinetic model. Med Phys 2019; 47:781-789. [DOI: 10.1002/mp.13916] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/19/2019] [Accepted: 11/04/2019] [Indexed: 02/02/2023] Open
Affiliation(s)
- Yoshiyuki Hirano
- Heavy Ion Medical Center Gunma University 3‐39‐22 Showa‐Machi Maebashi Gunma371‐8511Japan
| | - Satoshi Kodaira
- National Institute of Radiological SciencesNational Institutes for Quantum and Radiological Science and Technology 4-9-1 Anagawa Inage‐ku Chiba263‐8555Japan
| | - Hikaru Souda
- Heavy Ion Medical Center Gunma University 3‐39‐22 Showa‐Machi Maebashi Gunma371‐8511Japan
| | - Kohei Osaki
- Heavy Ion Medical Center Gunma University 3‐39‐22 Showa‐Machi Maebashi Gunma371‐8511Japan
| | - Masami Torikoshi
- Heavy Ion Medical Center Gunma University 3‐39‐22 Showa‐Machi Maebashi Gunma371‐8511Japan
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9
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Han S, Yoo SH, Shin JI, Kim EH, Jung WG, Kim KB, Matsumura A, Kanai T, Tran LT, Chartier L, James B, Rosenfeld AB. Study on the RBE estimation for carbon beam scanning irradiation using a solid-state microdosimeter. Med Phys 2019; 47:363-370. [PMID: 31732963 DOI: 10.1002/mp.13924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 11/07/2019] [Accepted: 11/07/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to study the field size effect on the estimated Relative Biological Effectiveness (RBE) for carbon scanning beam irradiation. METHODS A silicon-on-insulator (SOI) microdosimeter system developed by the Centre for Medical Radiation Physics, University of Wollongong, Australia, was used for lineal-energy measurements (microdosimetric quantity). The RBE values were derived based on the modified microdosimetric kinetic model (MKM) at different depths in a water phantom in the scanning carbon beam for various scanned areas. RESULTS Our study shows that the difference in RBE values derived from the SOI microdosimeter measurements with the MKM model and from the Treatment Planning System (TPS). The difference of the RBE values is within 6.5 % at the peak point of the spread-out Bragg Peak (SOBP) region. Compared to the spot-beam, RBE values obtained in the scanned-beam with a larger scanned area of 1.0 × 1.0 cm2 have better agreement with which estimated by the TPS. CONCLUSIONS This study shows the possibility of using the SOI microdosimeter system as a quality assurance (QA) tool for RBE evaluation in carbon-pencil beam scanning radiotherapy.
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Affiliation(s)
- Soorim Han
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Seung Hoon Yoo
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jae Ik Shin
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Eun Ho Kim
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Won-Gyun Jung
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Kum Bae Kim
- Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | | | | | - Linh T Tran
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Lachlan Chartier
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Benjamin James
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Anatoly B Rosenfeld
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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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] [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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Verkhovtsev A, Surdutovich E, Solov’yov AV. Phenomenon-based evaluation of relative biological effectiveness of ion beams by means of the multiscale approach. Cancer Nanotechnol 2019. [DOI: 10.1186/s12645-019-0049-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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12
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Parisi A, Chiriotti S, De Saint-Hubert M, Van Hoey O, Vandevoorde C, Beukes P, de Kock EA, Symons J, Camero JN, Slabbert J, Mégret P, Debrot E, Bolst D, Rosenfeld A, Vanhavere F. A novel methodology to assess linear energy transfer and relative biological effectiveness in proton therapy using pairs of differently doped thermoluminescent detectors. Phys Med Biol 2019; 64:085005. [PMID: 30650402 DOI: 10.1088/1361-6560/aaff20] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new methodology for assessing linear energy transfer (LET) and relative biological effectiveness (RBE) in proton therapy beams using thermoluminescent detectors is presented. The method is based on the different LET response of two different lithium fluoride thermoluminescent detectors (LiF:Mg,Ti and LiF:Mg,Cu,P) for measuring charged particles. The relative efficiency of the two detector types was predicted using the recently developed Microdosimetric d(z) Model in combination with the Monte Carlo code PHITS. Afterwards, the calculated ratio of the expected response of the two detector types was correlated with the fluence- and dose- mean values of the unrestricted proton LET. Using the obtained proton dose mean LET as input, the RBE was assessed using a phenomenological biophysical model of cell survival. The aforementioned methodology was benchmarked by exposing the detectors at different depths within the spread out Bragg peak (SOBP) of a clinical proton beam at iThemba LABS. The assessed LET values were found to be in good agreement with the results of radiation transport computer simulations performed using the Monte Carlo code GEANT4. Furthermore, the estimated RBE values were compared with the RBE values experimentally determined by performing colony survival measurements with Chinese Hamster Ovary (CHO) cells during the same experimental run. A very good agreement was found between the results of the proposed methodology and the results of the in vitro study.
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Affiliation(s)
- Alessio Parisi
- Belgian Nuclear Research Centre SCK·CEN, Mol, Belgium. University of Mons, Faculty of Engineering, Mons, Belgium. Author to whom any correspondence should be addressed
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13
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Hirano Y, Kodaira S, Souda H, Matsumura A, Torikoshi M. Linear energy transfer (LET) spectra and survival fraction distribution based on the CR-39 plastic charged-particle detector in a spread-out Bragg peak irradiation by a 12C beam. Phys Med Biol 2018; 63:185006. [PMID: 30113018 DOI: 10.1088/1361-6560/aadaa6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Facilities for heavy ion therapies are steadily increasing in number worldwide. One of the advantages of heavy ions is their high relative biological effect (RBE). In a model used at NIRS (National Institute of Radiological Sciences), linear energy transfer (LET) spectra are required to estimate biological dose (physical dose × RBE). The CR-39 plastic charged-particle detector (CR-39) is suitable for measurement of LET. For the present study, done at the Gunma University Heavy Ion Medical Center (GHMC), we measured LET spectra at 11 depths in spread-out Bragg peak (SOBP) irradiation by a 12C beam of 380 MeV/u. The lower threshold of the CR-39 to measure LET was about 5 keV µm-1 due to poor sensitivity for low LET. Then we calculated biological dose and survival fraction distributions and compared them with treatment planning results at GHMC. We used Monte Carlo simulation (Geant4) to calculate LET spectra. The simulation results were in good agreement with the experimental spectra. Moreover, the biological dose and survival fraction distributions estimated from the CR-39 reproduced the treatment planning. The CR-39 is suitable for estimating biological dose in carbon ion therapy.
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Affiliation(s)
- Yoshiyuki Hirano
- Heavy Ion Medical Center, Gunma University, 3-39-22 Showa-Machi, Maebashi, Gunma 371-8511, Japan. Present address: Department of Radiological Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673, Japan
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Colautti P, Conte V, Selva A, Chiriotti S, Pola A, Bortot D, Fazzi A, Agosteo S, Ciocca M. MICRODOSIMETRIC STUDY AT THE CNAO ACTIVE-SCANNING CARBON-ION BEAM. RADIATION PROTECTION DOSIMETRY 2018; 180:157-161. [PMID: 29087524 DOI: 10.1093/rpd/ncx217] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Indexed: 06/07/2023]
Abstract
The Italian National Centre for Oncological Hadrontherapy (CNAO) has been treating patients since 2011 with carbon-ion beams using the active-scanning modality. In such irradiation modality, the beam spot, which scans the treatment area, is characterised by very high particle-fluence rates (more than 105 s-1 mm-2). Moreover, the Bragg-peak is only ~1 mm-FWHM. Commercial tissue-equivalent proportional counters (TEPC), like the Far West Technologies LET-½, are large, hence they have limited capability to measure at high counting fluence rates. In this study we have used two home-made detectors, a mini-TEPC 0.81 mm2 in sensitive area and a silicon telescope 0.125 mm2 in sensitive area, to perform microdosimetric measurements in the therapeutic carbon-ion beam of CNAO. A monoenergetic carbon-ion beam of 189.5 ± 0.3 MeV/u scanning a 3 × 3 cm2 area has been used. Spectral differences are visible in the low y-value region, but the mean microdosimetric values, measured with the two detectors, result to be pretty consistent, as well as the microdosimetric spectra in the high y-value region.
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Affiliation(s)
- P Colautti
- INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, Legnaro, Italy
| | - V Conte
- INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, Legnaro, Italy
| | - A Selva
- INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, Legnaro, Italy
| | - S Chiriotti
- Belgian Nuclear Research Centre, SCK•CEN, Boeretang 200, Mol, Belgium
| | - A Pola
- Politecnico di Milano, Dipartimento di Energia, via La Masa 34, Milano, Italy
- INFN, Sezione di Milano, via Celoria 16, Milano, Italy
| | - D Bortot
- Politecnico di Milano, Dipartimento di Energia, via La Masa 34, Milano, Italy
- INFN, Sezione di Milano, via Celoria 16, Milano, Italy
| | - A Fazzi
- Politecnico di Milano, Dipartimento di Energia, via La Masa 34, Milano, Italy
- INFN, Sezione di Milano, via Celoria 16, Milano, Italy
| | - S Agosteo
- Politecnico di Milano, Dipartimento di Energia, via La Masa 34, Milano, Italy
- INFN, Sezione di Milano, via Celoria 16, Milano, Italy
| | - M Ciocca
- Fondazione CNAO, Strada Campeggi 53, Pavia, Italy
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15
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Chartier L, Tran LT, Bolst D, Guatelli S, Pogossov A, Prokopovich DA, Reinhard MI, Perevertaylo V, Anderson S, Beltran C, Matsufuji N, Jackson M, Rosenfeld AB. MICRODOSIMETRIC APPLICATIONS IN PROTON AND HEAVY ION THERAPY USING SILICON MICRODOSIMETERS. RADIATION PROTECTION DOSIMETRY 2018; 180:365-371. [PMID: 29069515 DOI: 10.1093/rpd/ncx226] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Using the CMRP 'bridge' μ+ probe, microdosimetric measurements were undertaken out-of-field using a therapeutic scanning proton pencil beam and in-field using a 12C ion therapy field. These measurements were undertaken at Mayo Clinic, Rochester, USA and at HIMAC, Chiba, Japan, respectively. For a typical proton field used in the treatment of deep-seated tumors, we observed dose-equivalent values ranging from 0.62 to 0.99 mSv/Gy at locations downstream of the distal edge. Lateral measurements at depths close to the entrance and along the SOBP plateau were found to reach maximum values of 3.1 mSv/Gy and 5.3 mSv/Gy at 10 mm from the field edge, respectively, and decreased to ~0.04 mSv/Gy 120 mm from the field edge. The ability to measure the dose-equivalent with high spatial resolution is particularly relevant to healthy tissue dose calculations in hadron therapy treatments. We have also shown qualitatively and quantitively the effects critical organ motion would have in treatment using microdosimetric spectra. Large differences in spectra and RBE10 were observed for treatments where miscalculations of 12C ion range would result in critical structures being irradiated, showing the importance of motion management.
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Affiliation(s)
- L Chartier
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - L T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - D Bolst
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - S Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - A Pogossov
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - D A Prokopovich
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- Ionising Radiation, Nuclear Stewardship Platform, NSTLI, ANSTO, Lucas Heights, NSW, Australia
| | - M I Reinhard
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- Ionising Radiation, Nuclear Stewardship Platform, NSTLI, ANSTO, Lucas Heights, NSW, Australia
| | | | - S Anderson
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - C Beltran
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - N Matsufuji
- National Institute for Quantum and Radiological Science and Technology, Japan
| | - M Jackson
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- School of Medicine, University of New South Wales, Kensington, NSW, Australia
| | - A B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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16
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Chen Y, Li J, Li C, Qiu R, Wu Z. A modified microdosimetric kinetic model for relative biological effectiveness calculation. ACTA ACUST UNITED AC 2017; 63:015008. [DOI: 10.1088/1361-6560/aa9a68] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Bolst D, Tran LT, Chartier L, Prokopovich DA, Pogossov A, Guatelli S, Reinhard MI, Petasecca M, Lerch ML, Matsufuji N, Perevertaylo VL, Fleta C, Pellegrini G, Jackson M, Rosenfeld AB. RBE study using solid state microdosimetry in heavy ion therapy. RADIAT MEAS 2017. [DOI: 10.1016/j.radmeas.2017.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Cunha M, Monini C, Testa E, Beuve M. NanOx, a new model to predict cell survival in the context of particle therapy. Phys Med Biol 2016; 62:1248-1268. [PMID: 27995904 DOI: 10.1088/1361-6560/aa54c9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Particle therapy is increasingly attractive for the treatment of tumors and the number of facilities offering it is rising worldwide. Due to the well-known enhanced effectiveness of ions, it is of utmost importance to plan treatments with great care to ensure tumor killing and healthy tissues sparing. Hence, the accurate quantification of the relative biological effectiveness (RBE) of ions, used in the calculation of the biological dose, is critical. Nevertheless, the RBE is a complex function of many parameters and its determination requires modeling. The approaches currently used have allowed particle therapy to thrive, but still show some shortcomings. We present herein a short description of a new theoretical framework, NanOx, to calculate cell survival in the context of particle therapy. It gathers principles from existing approaches, while addressing some of their weaknesses. NanOx is a multiscale model that takes the stochastic nature of radiation at nanometric and micrometric scales fully into account, integrating also the chemical aspects of radiation-matter interaction. The latter are included in the model by means of a chemical specific energy, determined from the production of reactive chemical species induced by irradiation. Such a production represents the accumulation of oxidative stress and sublethal damage in the cell, potentially generating non-local lethal events in NanOx. The complementary local lethal events occur in a very localized region and can, alone, lead to cell death. Both these classes of events contribute to cell death. The comparison between experimental data and model predictions for the V79 cell line show a good agreement. In particular, the dependence of the typical shoulders of cell survival curves on linear energy transfer are well described, but also the effectiveness of different ions, including the overkill effect. These results required the adjustment of a number of parameters compatible with the application of the model in a clinical scenario thereby showing the potential of NanOx. Said parameters are discussed in detail in this paper.
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Affiliation(s)
- M Cunha
- Université de Lyon, F-69622, Lyon, France. Université de Lyon 1, Villeurbanne, France. CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, France
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19
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Wambersie A, Menzel H, Gueulette J, Pihet P. Fifteen symposia on microdosimetry: implications for modern particle-beam cancer radiotherapy. RADIATION PROTECTION DOSIMETRY 2015; 166:328-333. [PMID: 25969525 DOI: 10.1093/rpd/ncv304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The objective of microdosimetry was, and still is, to identify physical descriptions of the initial physical processes of ionising radiation interacting with biological matter which correlate with observed radiobiological effects with a view to improve the understanding of radiobiological mechanisms and effects. The introduction of therapy with particles starting with fast neutrons followed by negative pions, protons and light ions necessitated the application of biological weighting factors for absorbed dose in order to account for differences of the relative biological effectiveness (RBE). Dedicated radiobiological experiments in therapy beams with mammalian cells and with laboratory animals provided sets of RBE values which are used to evaluate empirical 'clinical RBE values'. The combination of such experiments with microdosimetric measurements in identical conditions offered the possibility to establish semi-empirical relationships between microdosimetric parameters and results of RBE studies.
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Affiliation(s)
- A Wambersie
- Université Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels, Belgium
| | - H Menzel
- Université Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels, Belgium CERN, Geneva, Switzerland
| | - J Gueulette
- Université Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels, Belgium
| | - P Pihet
- Université Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels, Belgium Institut de Radioprotection et de Sûreté Nucléaire, FontenayauxRoses, France
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20
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Huang YW, Pan CY, Hsiao YY, Chao TC, Lee CC, Tung CJ. Monte Carlo simulations of the relative biological effectiveness for DNA double strand breaks from 300 MeV u(-1) carbon-ion beams. Phys Med Biol 2015; 60:5995-6012. [PMID: 26183156 DOI: 10.1088/0031-9155/60/15/5995] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Monte Carlo simulations are used to calculate the relative biological effectiveness (RBE) of 300 MeV u(-1) carbon-ion beams at different depths in a cylindrical water phantom of 10 cm radius and 30 cm long. RBE values for the induction of DNA double strand breaks (DSB), a biological endpoint closely related to cell inactivation, are estimated for monoenergetic and energy-modulated carbon ion beams. Individual contributions to the RBE from primary ions and secondary nuclear fragments are simulated separately. These simulations are based on a multi-scale modelling approach by first applying the FLUKA (version 2011.2.17) transport code to estimate the absorbed doses and fluence energy spectra, then using the MCDS (version 3.10A) damage code for DSB yields. The approach is efficient since it separates the non-stochastic dosimetry problem from the stochastic DNA damage problem. The MCDS code predicts the major trends of the DSB yields from detailed track structure simulations. It is found that, as depth is increasing, RBE values increase slowly from the entrance depth to the plateau region and change substantially in the Bragg peak region. RBE values reach their maxima at the distal edge of the Bragg peak. Beyond this edge, contributions to RBE are entirely from nuclear fragments. Maximum RBE values at the distal edges of the Bragg peak and the spread-out Bragg peak are, respectively, 3.0 and 2.8. The present approach has the flexibility to weight RBE contributions from different DSB classes, i.e. DSB0, DSB+ and DSB++.
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Affiliation(s)
- Y W Huang
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Kweishan Taoyuan, Taiwan
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21
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Inaniwa T, Kanematsu N, Matsufuji N, Kanai T, Shirai T, Noda K, Tsuji H, Kamada T, Tsujii H. Reformulation of a clinical-dose system for carbon-ion radiotherapy treatment planning at the National Institute of Radiological Sciences, Japan. Phys Med Biol 2015; 60:3271-86. [DOI: 10.1088/0031-9155/60/8/3271] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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22
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Horiguchi H, Sato T, Kumada H, Yamamoto T, Sakae T. Estimation of relative biological effectiveness for boron neutron capture therapy using the PHITS code coupled with a microdosimetric kinetic model. JOURNAL OF RADIATION RESEARCH 2015; 56:382-90. [PMID: 25428243 PMCID: PMC4380055 DOI: 10.1093/jrr/rru109] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/21/2014] [Accepted: 10/24/2014] [Indexed: 05/30/2023]
Abstract
The absorbed doses deposited by boron neutron capture therapy (BNCT) can be categorized into four components: α and (7)Li particles from the (10)B(n, α)(7)Li reaction, 0.54-MeV protons from the (14)N(n, p)(14)C reaction, the recoiled protons from the (1)H(n, n) (1)H reaction, and photons from the neutron beam and (1)H(n, γ)(2)H reaction. For evaluating the irradiation effect in tumors and the surrounding normal tissues in BNCT, it is of great importance to estimate the relative biological effectiveness (RBE) for each dose component in the same framework. We have, therefore, established a new method for estimating the RBE of all BNCT dose components on the basis of the microdosimetric kinetic model. This method employs the probability density of lineal energy, y, in a subcellular structure as the index for expressing RBE, which can be calculated using the microdosimetric function implemented in the particle transport simulation code (PHITS). The accuracy of this method was tested by comparing the calculated RBE values with corresponding measured data in a water phantom irradiated with an epithermal neutron beam. The calculation technique developed in this study will be useful for biological dose estimation in treatment planning for BNCT.
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Affiliation(s)
- Hironori Horiguchi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tatsuhiko Sato
- Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2-4, Shirakata-shirane, Tokai, Ibaraki 319-1195, Japan
| | - Hiroaki Kumada
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan Proton Medical Research Center, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tetsuya Yamamoto
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Takeji Sakae
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan Proton Medical Research Center, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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23
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Microdosimetry spectra and relative biological effectiveness of 15 and 30 MeV proton beams. Appl Radiat Isot 2015; 97:101-105. [DOI: 10.1016/j.apradiso.2014.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 11/16/2014] [Accepted: 12/18/2014] [Indexed: 11/17/2022]
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24
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Wei D, Yang J, Li W, Wang K, Zhang Q, Qiu J. Increased resting functional connectivity of the medial prefrontal cortex in creativity by means of cognitive stimulation. Cortex 2014; 51:92-102. [DOI: 10.1016/j.cortex.2013.09.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/14/2013] [Accepted: 09/13/2013] [Indexed: 02/04/2023]
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25
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Microdosimetric calculation of penumbra for biological dose in wobbled carbon-ion beams with Monte Carlo Method. Radiol Phys Technol 2013; 6:415-22. [DOI: 10.1007/s12194-013-0214-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/12/2013] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
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26
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Kase Y, Himukai T, Nagano A, Tameshige Y, Minohara S, Matsufuji N, Mizoe J, Fossati P, Hasegawa A, Kanai T. Preliminary calculation of RBE-weighted dose distribution for cerebral radionecrosis in carbon-ion treatment planning. JOURNAL OF RADIATION RESEARCH 2011; 52:789-796. [PMID: 21921434 DOI: 10.1269/jrr.11044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Cerebral radionecrosis is a significant side effect in radiotherapy for brain cancer. The purpose of this study is to calculate the relative biological effectiveness (RBE) of carbon-ion beams on brain cells and to show RBE-weighted dose distributions for cerebral radionecrosis speculation in a carbon-ion treatment planning system. The RBE value of the radionecrosis for the carbon-ion beam is calculated by the modified microdosimetric kinetic model on the assumption of a typical clinical α/β ratio of 2 Gy for cerebral radionecrosis in X-rays. This calculation method for the RBE-weighted dose is built into the treatment planning system for the carbon-ion radiotherapy. The RBE-weighted dose distributions are calculated on computed tomography (CT) images of four patients who had been treated by carbon-ion radiotherapy for astrocytoma (WHO grade 2) and who suffered from necrosis around the target areas. The necrotic areas were detected by brain scans via magnetic resonance imaging (MRI) after the treatment irradiation. The detected necrotic areas are easily found near high RBE-weighted dose regions. The visual comparison between the RBE-weighted dose distribution and the necrosis region indicates that the RBE-weighted dose distribution will be helpful information for the prediction of radionecrosis areas after carbon-ion radiotherapy.
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Affiliation(s)
- Yuki Kase
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba-shi, Chiba 263-8555, Japan.
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