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Glowa C, Saager M, Hintz L, Euler-Lange R, Peschke P, Brons S, Scholz M, Mein S, Mairani A, Karger CP. Relative biological effectiveness of oxygen ion beams in the rat spinal cord: Dependence on linear energy transfer and dose and comparison with model predictions. Phys Imaging Radiat Oncol 2024; 30:100581. [PMID: 38711920 PMCID: PMC11070926 DOI: 10.1016/j.phro.2024.100581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 05/08/2024] Open
Abstract
Background and purpose Ion beams exhibit an increased relative biological effectiveness (RBE) with respect to photons. This study determined the RBE of oxygen ion beams as a function of linear energy transfer (LET) and dose in the rat spinal cord. Materials and methods The spinal cord of rats was irradiated at four different positions of a 6 cm spread-out Bragg-peak (LET: 26, 66, 98 and 141 keV/µm) using increasing levels of single and split oxygen ion doses. Dose-response curves were established for the endpoint paresis grade II and based on ED50 (dose at 50 % effect probability), the RBE was determined and compared to model predictions. Results When LET increased from 26 to 98 keV/µm, ED50 decreased from 17.2 ± 0.3 Gy to 13.5 ± 0.4 Gy for single and from 21.7 ± 0.4 Gy to 15.5 ± 0.5 Gy for split doses, however, at 141 keV/µm, ED50 rose again to 15.8 ± 0.4 Gy and 17.2 ± 0.4 Gy, respectively. As a result, the RBE increased from 1.43 ± 0.05 to 1.82 ± 0.08 (single dose) and from 1.58 ± 0.04 to 2.21 ± 0.08 (split dose), respectively, before declining again to 1.56 ± 0.06 for single and 1.99 ± 0.06 for split doses at the highest LET. Deviations from RBE-predictions were model-dependent. Conclusion This study established first RBE data for the late reacting central nervous system after single and split doses of oxygen ions. The data was used to validate the RBE-dependence on LET and dose of three RBE-models. This study extends the existing data base for protons, helium and carbon ions and provides important information for future patient treatments with oxygen ions.
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Affiliation(s)
- Christin Glowa
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiation Oncology and Radiotherapy, University Hospital Heidelberg, Germany
| | - Maria Saager
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Lisa Hintz
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Rosemarie Euler-Lange
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiooncology/Radiobiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter Peschke
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Stephan Brons
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
| | - Michael Scholz
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Stewart Mein
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andrea Mairani
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- National Centre of Oncological Hadrontherapy (CNAO), Medical Physics, Pavia, Italy
| | - Christian P. Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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Wang W, Li P, Shahnazi K, Wu X, Zhao J. Calculating dose-averaged linear energy transfer in an analytical treatment planning system for carbon-ion radiotherapy. J Appl Clin Med Phys 2022; 24:e13866. [PMID: 36527366 PMCID: PMC9924117 DOI: 10.1002/acm2.13866] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/08/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Compelling evidence shows the association between the relative biological effectiveness (RBE) of carbon-ion radiotherapy (CIRT) and the dose averaged linear energy transfer (LETd). However, the ability to calculate the LETd in commercially available treatment planning systems (TPS) is lacking. PURPOSE This study aims to develop a method of calculating the LETd of CIRT plans that could be robustly carried out in RayStation (V10B, Raysearch, Sweden). METHODS The calculation used the fragment spectra in RayStation for the CIRT treatment planning. The dose-weighted averaging procedure was supported by the microdosimetric kinetic model (MKM). The MKM-based pencil beam dose engine (PBA, v4.2) for calculating RBE-weighted doses was reformulated to become a LET-weighted calculating engine. A separate module was then configured to inversely calculate the LETd from the absorbed dose of a plan and the associated fragment spectra. In this study, the ion and energy-specific LET table in the LETd module was further matched with the values decoded from the baseline data of the Syngo TPS (V13C, Siemens, Germany). The LETd distributions of several monoenergetic and modulated beams were calculated and validated against the values derived from the Syngo TPS and the published data. RESULTS The differences in LETds of the monoenergetic beams between the new method and the traditional method were within 3% in the entrance and Bragg-peak regions. However, a larger difference was observed in the distal region. The results of the modulated beams were in good agreement with the works from the published literature. CONCLUSIONS The method presented herein reformulates the MKM dose engine in the RayStation TPS to inversely calculate LETds. The robustness and accuracy were demonstrated.
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Affiliation(s)
- Weiwei Wang
- Department of Medical PhysicsShanghai Proton and Heavy Ion CenterFudan University Cancer HospitalShanghai Key Laboratory of Radiation Oncology (20dz2261000)Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghaiChina,Institute of Modern PhysicsApplied Ion Beam Physics LaboratoryFudan UniversityShanghaiChina
| | - Ping Li
- Department of Radiation OncologyShanghai Proton and Heavy Ion CenterShanghai Key Laboratory of Radiation Oncology (20dz2261000)Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghaiChina
| | - Kambiz Shahnazi
- Department of Medical PhysicsShanghai Proton and Heavy Ion CenterFudan University Cancer HospitalShanghai Key Laboratory of Radiation Oncology (20dz2261000)Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghaiChina
| | - Xiaodong Wu
- Department of Medical PhysicsShanghai Proton and Heavy Ion CenterFudan University Cancer HospitalShanghai Key Laboratory of Radiation Oncology (20dz2261000)Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghaiChina
| | - Jingfang Zhao
- Department of Medical PhysicsShanghai Proton and Heavy Ion CenterFudan University Cancer HospitalShanghai Key Laboratory of Radiation Oncology (20dz2261000)Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghaiChina,Department of Medical PhysicsShanghai Proton and Heavy Ion CenterFudan University Cancer HospitalShanghaiChina
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Kozłowska WS, Carante MP, Aricò G, Embriaco A, Ferrari A, Magro G, Mairani A, Ramos R, Sala P, Georg D, Ballarini F. First application of the BIANCA biophysical model to carbon-ion patient cases. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac702b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 05/16/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. The main objective of this work consists of applying, for the first time, the BIANCA (BIophysical ANalysis of Cell death and chromosome Aberrations) biophysical model to the RBE calculation for C-ion cancer patients, and comparing the outcomes with those obtained by the LEM I model, which is applied in clinics. Indeed, the continuous development of heavy-ion cancer therapy requires modelling of biological effects of ion beams on tumours and normal tissues. The relative biological effectiveness (RBE) of heavy ions is higher than that of protons, with a significant variation along the beam path. Therefore, it requires a precise modelling, especially for the pencil-beam scanning technique. Currently, two radiobiological models, LEM I and MKM, are in use for heavy ions in scanned pencil-beam facilities. Approach. Utilizing an interface with the FLUKA Particle Therapy Tool, BIANCA was applied to re-calculate the RBE-weighted dose distribution for carbon-ion treatment of three patients (chordoma, head-and-neck and prostate) previously irradiated at CNAO, where radiobiological optimization was based on LEM I. The predictions obtained by BIANCA were based either on chordoma cell survival (RBE
surv
), or on dicentric aberrations in peripheral blood lymphocytes (RBE
ab
), which are indicators of late normal tissue damage, including secondary tumours. The simulation outcomes were then compared with those provided by LEM I. Main results. While in the target and in the entrance channel BIANCA predictions were lower than those obtained by LEM I, the two models provided very similar results in the considered OAR. The observed differences between RBE
surv
and RBE
ab
(which were also dependent on fractional dose and LET) suggest that in normal tissues the information on cell survival should be integrated by information more closely related to the induction of late damage, such as chromosome aberrations. Significance. This work showed that BIANCA is suitable for treatment plan optimization in ion-beam therapy, especially considering that it can predict both cell survival and chromosome aberrations and has previously shown good agreement with carbon-ion experimental data.
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Relative biological effectiveness of single and split helium ion doses in the rat spinal cord increases strongly with linear energy transfer. Radiother Oncol 2022; 170:224-230. [PMID: 35367526 DOI: 10.1016/j.radonc.2022.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 03/16/2022] [Accepted: 03/28/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE Determination of the relative biological effectiveness (RBE) of helium ions as a function of linear energy transfer (LET) for single and split doses using the rat cervical spinal cord as model system for late-responding normal tissue. MATERIAL AND METHODS The rat cervical spinal cord was irradiated at four different positions within a 6 cm spread-out Bragg-peak (SOBP) (LET 2.9, 9.4, 14.4 and 20.7 keV/µm) using increasing levels of single or split doses of helium ions. Dose-response curves were determined and based on TD50-values (dose at 50% effect probability using paresis II as endpoint), RBE-values were derived for the endpoint of radiation-induced myelopathy. RESULTS With increasing LET, RBE-values increased from 1.13 ± 0.04 to 1.42 ± 0.05 (single dose) and 1.12 ± 0.03 to 1.50 ± 0.04 (split doses) as TD50-values decreased from 21.7 ± 0.3 Gy to 17.3 ± 0.3 Gy (single dose) and 30.6 ± 0.3 Gy to 22.9 ± 0.3 Gy (split doses), respectively. RBE-models (LEM I and IV, mMKM) deviated differently for single and split doses but described the RBE variation in the high-LET region sufficiently accurate. CONCLUSION This study established the LET-dependence of the RBE for late effects in the central nervous system after single and split doses of helium ions. The results extend the existing database for protons and carbon ions and allow systematic testing of RBE-models. While the RBE-values of helium were generally lower than for carbon ions, the increase at the distal edge of the Bragg-peak was larger than for protons, making detailed RBE-modeling necessary.
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Pfuhl T, Friedrich T, Scholz M. Comprehensive comparison of local effect model IV predictions with the particle irradiation data ensemble. Med Phys 2021; 49:714-726. [PMID: 34766635 DOI: 10.1002/mp.15343] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The increased relative biological effectiveness (RBE) of ions is one of the key benefits of ion radiotherapy compared to conventional radiotherapy with photons. To account for the increased RBE of ions during the process of ion radiotherapy treatment planning, a robust model for RBE predictions is indispensable. Currently, at several ion therapy centers the local effect model I (LEM I) is applied to predict the RBE, which varies with biological and physical impacting factors. After the introduction of LEM I, several model improvements were implemented, leading to the current version, LEM IV, which is systematically tested in this study. METHODS As a comprehensive RBE model should give consistent results for a large variety of ion species and energies, the particle irradiation data ensemble (PIDE) is used to systematically validate the LEM IV. The database covers over 1100 photon and ion survival experiments in form of their linear-quadratic parameters for a wide range of ion types and energies. This makes the database an optimal tool to challenge the systematic dependencies of the RBE model. After appropriate filtering of the database, 571 experiments were identified and used as test data. RESULTS The study confirms that the LEM IV reflects the RBE systematics observed in measurements well. It is able to reproduce the dependence of RBE on the linear energy transfer (LET) as well as on the αγ /βγ ratio for several ion species in a wide energy range. Additionally, the systematic quantitative analysis revealed precision capabilities and limits of the model. At lower LET values, the LEM IV tends to underestimate the RBE with an increasing underestimation with increasing atomic number of the ion. At higher LET values, the LEM IV overestimates the RBE for protons or helium ions, whereas the predictions for heavier ions match experimental data well. CONCLUSIONS The LEM IV is able to predict general RBE characteristics for several ion species in a broad energy range. The accuracy of the predictions is reasonable considering the small number of input parameters needed by the model. The detailed quantification of possible systematic deviations, however, enables to identify not only strengths but also limitations of the model. The gained knowledge can be used to develop model adjustments to further improve the model accuracy, which is on the way.
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Affiliation(s)
- Tabea Pfuhl
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany.,Institute for Solid State Physics, Technische Universität Darmstadt, Darmstadt, Germany
| | - Thomas Friedrich
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
| | - Michael Scholz
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
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The RBE in ion beam radiotherapy: In vivo studies and clinical application. Z Med Phys 2021; 31:105-121. [PMID: 33568337 DOI: 10.1016/j.zemedi.2020.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/23/2020] [Accepted: 12/04/2020] [Indexed: 12/15/2022]
Abstract
Ion beams used for radiotherapy exhibit an increased relative biological effectiveness (RBE), which depends on several physical treatment parameters as well as on biological factors of the irradiated tissues. While the RBE is an experimentally well-defined quantity, translation to patients is complex and requires radiobiological studies, dedicated models to calculate the RBE in treatment planning as well as strategies for dose prescription. Preclinical in vivo studies and analysis of clinical outcome are important to validate and refine RBE-models. This review describes the concept of the experimental and clinical RBE and explains the fundamental dependencies of the RBE based on in vitro experiments. The available preclinical in vivo studies on normal tissue and tumor RBE for ions heavier than protons are reviewed in the context of the historical and present development of ion beam radiotherapy. In addition, the role of in vivo RBE-values in the development and benchmarking of RBE-models as well as the transition of these models to clinical application are described. Finally, limitations in the translation of experimental RBE-values into clinical application and the direction of future research are discussed.
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Tinganelli W, Durante M. Carbon Ion Radiobiology. Cancers (Basel) 2020; 12:E3022. [PMID: 33080914 PMCID: PMC7603235 DOI: 10.3390/cancers12103022] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
Radiotherapy using accelerated charged particles is rapidly growing worldwide. About 85% of the cancer patients receiving particle therapy are irradiated with protons, which have physical advantages compared to X-rays but a similar biological response. In addition to the ballistic advantages, heavy ions present specific radiobiological features that can make them attractive for treating radioresistant, hypoxic tumors. An ideal heavy ion should have lower toxicity in the entrance channel (normal tissue) and be exquisitely effective in the target region (tumor). Carbon ions have been chosen because they represent the best combination in this direction. Normal tissue toxicities and second cancer risk are similar to those observed in conventional radiotherapy. In the target region, they have increased relative biological effectiveness and a reduced oxygen enhancement ratio compared to X-rays. Some radiobiological properties of densely ionizing carbon ions are so distinct from X-rays and protons that they can be considered as a different "drug" in oncology, and may elicit favorable responses such as an increased immune response and reduced angiogenesis and metastatic potential. The radiobiological properties of carbon ions should guide patient selection and treatment protocols to achieve optimal clinical results.
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Affiliation(s)
- Walter Tinganelli
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforchung, Planckstraße 1, 64291 Darmstadt, Germany;
| | - Marco Durante
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforchung, Planckstraße 1, 64291 Darmstadt, Germany;
- Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany
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Mein S, Klein C, Kopp B, Magro G, Harrabi S, Karger CP, Haberer T, Debus J, Abdollahi A, Dokic I, Mairani A. Assessment of RBE-Weighted Dose Models for Carbon Ion Therapy Toward Modernization of Clinical Practice at HIT: In Vitro, in Vivo, and in Patients. Int J Radiat Oncol Biol Phys 2020; 108:779-791. [PMID: 32504659 DOI: 10.1016/j.ijrobp.2020.05.041] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/02/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE Present-day treatment planning in carbon ion therapy is conducted with assumptions for a limited number of tissue types and models for effective dose. Here, we comprehensively assess relative biological effectiveness (RBE) in carbon ion therapy and associated models toward the modernization of current clinical practice in effective dose calculation. METHODS Using 2 human (A549, H460) and 2 mouse (B16, Renca) tumor cell lines, clonogenic cell survival assay was performed for examination of changes in RBE along the full range of clinical-like spread-out Bragg peak (SOBP) fields. Prediction power of the local effect model (LEM1 and LEM4) and the modified microdosimetric kinetic model (mMKM) was assessed. Experimentation and analysis were carried out in the frame of a multidimensional end point study for clinically relevant ranges of physical dose (D), dose-averaged linear energy transfer (LETd), and base-line photon radio-sensitivity (α/β)x. Additionally, predictions were compared against previously reported RBE measurements in vivo and surveyed in patient cases. RESULTS RBE model prediction performance varied among the investigated perspectives, with mMKM prediction exhibiting superior agreement with measurements both in vitro and in vivo across the 3 investigated end points. LEM1 and LEM4 performed their best in the highest LET conditions but yielded overestimations and underestimations in low/midrange LET conditions, respectively, as demonstrated by comparison with measurements. Additionally, the analysis of patient treatment plans revealed substantial variability across the investigated models (±20%-30% uncertainty), largely dependent on the selected model and absolute values for input tissue parameters αx and βx. CONCLUSION RBE dependencies in vitro, in vivo, and in silico were investigated with respect to various clinically relevant end points in the context of tumor-specific tissue radio-sensitivity assignment and accurate RBE modeling. Discovered model trends and performances advocate upgrading current treatment planning schemes in carbon ion therapy and call for verification via clinical outcome analysis with large patient cohorts.
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Affiliation(s)
- Stewart Mein
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, Department of Radiation Oncology, Heidelberg Faculty of Medicine and Heidelberg University Hospital, Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany; German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Germany
| | - Carmen Klein
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, Department of Radiation Oncology, Heidelberg Faculty of Medicine and Heidelberg University Hospital, Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany; German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Germany
| | - Benedikt Kopp
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, Department of Radiation Oncology, Heidelberg Faculty of Medicine and Heidelberg University Hospital, Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany; German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Germany
| | - Giuseppe Magro
- National Centre of Oncological Hadrontherapy, Medical Physics, Pavia, Italy
| | - Semi Harrabi
- Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany; National Center for Tumor Diseases, Heidelberg, Germany; Heidelberg Ion-Beam Therapy Center, Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christian P Karger
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany
| | - Thomas Haberer
- Heidelberg Ion-Beam Therapy Center, Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Jürgen Debus
- German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Germany; National Center for Tumor Diseases, Heidelberg, Germany; Heidelberg Ion-Beam Therapy Center, Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Amir Abdollahi
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, Department of Radiation Oncology, Heidelberg Faculty of Medicine and Heidelberg University Hospital, Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany; German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Ivana Dokic
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; Division of Molecular and Translational Radiation Oncology, Department of Radiation Oncology, Heidelberg Faculty of Medicine and Heidelberg University Hospital, Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany; German Cancer Consortium Core-Center Heidelberg, German Cancer Research Center, Heidelberg, Germany; Clinical Cooperation Unit Radiation Oncology, Heidelberg Institute of Radiation Oncology, National Center for Radiation Oncology, Heidelberg University and German Cancer Research Center, Heidelberg, Germany.
| | - Andrea Mairani
- Clinical Cooperation Unit Translational Radiation Oncology, National Center for Tumor Diseases, Heidelberg University Hospital and German Cancer Research Center, Heidelberg, Germany; National Centre of Oncological Hadrontherapy, Medical Physics, Pavia, Italy; Heidelberg Ion-Beam Therapy Center, Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.
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In Vivo Validation of the BIANCA Biophysical Model: Benchmarking against Rat Spinal Cord RBE Data. Int J Mol Sci 2020; 21:ijms21113973. [PMID: 32492909 PMCID: PMC7312044 DOI: 10.3390/ijms21113973] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 12/25/2022] Open
Abstract
(1) Background: Cancer ion therapy is constantly growing thanks to its increased precision and, for heavy ions, its increased biological effectiveness (RBE) with respect to conventional photon therapy. The complex dependence of RBE on many factors demands biophysical modeling. Up to now, only the Local Effect Model (LEM), the Microdosimetric Kinetic Model (MKM), and the "mixed-beam" model are used in clinics. (2) Methods: In this work, the BIANCA biophysical model, after extensive benchmarking in vitro, was applied to develop a database predicting cell survival for different ions, energies, and doses. Following interface with the FLUKA Monte Carlo transport code, for the first time, BIANCA was benchmarked against in vivo data obtained by C-ion or proton irradiation of the rat spinal cord. The latter is a well-established model for CNS (central nervous system) late effects, which, in turn, are the main dose-limiting factors for head-and-neck tumors. Furthermore, these data have been considered to validate the LEM version applied in clinics. (3) Results: Although further benchmarking is desirable, the agreement between simulations and data suggests that BIANCA can predict RBE for C-ion or proton treatment of head-and-neck tumors. In particular, the agreement with proton data may be relevant if the current assumption of a constant proton RBE of 1.1 is revised. (4) Conclusions: This work provides the basis for future benchmarking against patient data, as well as the development of other databases for specific tumor types and/or normal tissues.
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Scholz M. State-of-the-Art and Future Prospects of Ion Beam Therapy: Physical and Radiobiological Aspects. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020. [DOI: 10.1109/trpms.2019.2935240] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Fractionated carbon ion irradiations of the rat spinal cord: comparison of the relative biological effectiveness with predictions of the local effect model. Radiat Oncol 2020; 15:6. [PMID: 31900185 PMCID: PMC6942289 DOI: 10.1186/s13014-019-1439-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/06/2019] [Indexed: 11/10/2022] Open
Abstract
Background To determine the relative biological effectiveness (RBE) and α/β-values after fractionated carbon ion irradiations of the rat spinal cord with varying linear energy transfer (LET) to benchmark RBE-model calculations. Material and methods The rat spinal cord was irradiated with 6 fractions of carbon ions at 6 positions within a 6 cm spread-out Bragg-peak (SOBP, LET: 16–99 keV/μm). TD50-values (dose at 50% complication probability) were determined from dose-response curves for the endpoint radiation induced myelopathy (paresis grade II) within 300 days after irradiation. Based on TD50-values of 15 MV photons, RBE-values were calculated and adding previously published data, the LET and fractional dose-dependence of the RBE was used to benchmark the local effect model (LEM I and IV). Results At six fractions, TD50-values decreased from 39.1 ± 0.4 Gy at 16 keV/μm to 17.5 ± 0.3 Gy at 99 keV/μm and the RBE increased accordingly from 1.46 ± 0.05 to 3.26 ± 0.13. Experimental α/β-ratios ranged from 6.9 ± 1.1 Gy to 44.3 ± 7.2 Gy and increased strongly with LET. Including all available data, comparison with model-predictions revealed that (i) LEM IV agrees better in the SOBP, while LEM I fits better in the entrance region, (ii) LEM IV describes the slope of the RBE within the SOBP better than LEM I, and (iii) in contrast to the strong LET-dependence, the RBE-deviations depend only weakly on fractionation within the measured range. Conclusions This study extends the available RBE data base to significantly lower fractional doses and performes detailed tests of the RBE-models LEM I and IV. In this comparison, LEM IV agrees better with the experimental data in the SOBP than LEM I. While this could support a model replacement in treatment planning, careful dosimetric analysis is required for the individual patient to evaluate potential clinical consequences.
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Gillmann C, Jäkel O, Karger CP. RBE-weighted doses in target volumes of chordoma and chondrosarcoma patients treated with carbon ion radiotherapy: Comparison of local effect models I and IV. Radiother Oncol 2019; 141:234-238. [PMID: 31522880 DOI: 10.1016/j.radonc.2019.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/30/2019] [Accepted: 08/09/2019] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND PURPOSE To compare the relative biological effectiveness (RBE)-weighted dose distributions in the target volume of chordoma and chondrosarcoma patients when using two different versions of the local effect model (LEM I vs. IV) under identical conditions. MATERIALS AND METHODS The patient collective included 59 patients treated with 20 fractions of carbon ion radiotherapy for chordoma and low-grade chondrosarcoma of the skull base at the Helmholtzzentrum für Schwerionenforschung (GSI) in 2002 and 2003. Prescribed doses to the planning target volume (PTV) were 60 (n = 49), 66 (n = 2) and 70 (n = 8) Gy (RBE). The original treatment plans that were initially biologically optimized with LEM I, were now recalculated using LEM IV based on the absorbed dose distributions. The resulting RBE-weighted dose distributions were quantitatively compared to assess the clinical impact of LEM IV relative to LEM I in the target volume. RESULTS LEM IV predicts 20-30 Gy (RBE) increased maximum doses as compared to LEM I, while minimum doses are decreased by 2-5 Gy (RBE). Population-based mean and median doses deviated by less than 2 Gy (RBE) between both models. CONCLUSIONS LEM I and LEM IV-based RBE-weighted doses in the target volume may be significantly different. Replacing the applied model in patient treatments may therefore lead to local over- or underdosages in the tumor. If LEM IV is to be tested clinically, comparisons of the RBE-weighted dose distributions of both models are required for the individual patients to assess whether the LEM IV-plan would also be acceptable and prescribed dose as well as clinical outcome data have to be carefully reassessed.
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Affiliation(s)
- Clarissa Gillmann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Oliver Jäkel
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Germany; Heidelberg Ion Beam Therapy Center (HIT), Heidelberg University Hospital, Germany
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Germany
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Stewart RD, Carlson DJ, Butkus MP, Hawkins R, Friedrich T, Scholz M. A comparison of mechanism-inspired models for particle relative biological effectiveness (RBE). Med Phys 2018; 45:e925-e952. [PMID: 30421808 DOI: 10.1002/mp.13207] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 09/05/2018] [Accepted: 09/13/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND SIGNIFICANCE The application of heavy ion beams in cancer therapy must account for the increasing relative biological effectiveness (RBE) with increasing penetration depth when determining dose prescriptions and organ at risk (OAR) constraints in treatment planning. Because RBE depends in a complex manner on factors such as the ion type, energy, cell and tissue radiosensitivity, physical dose, biological endpoint, and position within and outside treatment fields, biophysical models reflecting these dependencies are required for the personalization and optimization of treatment plans. AIM To review and compare three mechanism-inspired models which predict the complexities of particle RBE for various ion types, energies, linear energy transfer (LET) values and tissue radiation sensitivities. METHODS The review of models and mechanisms focuses on the Local Effect Model (LEM), the Microdosimetric-Kinetic (MK) model, and the Repair-Misrepair-Fixation (RMF) model in combination with the Monte Carlo Damage Simulation (MCDS). These models relate the induction of potentially lethal double strand breaks (DSBs) to the subsequent interactions and biological processing of DSB into more lethal forms of damage. A key element to explain the increased biological effectiveness of high LET ions compared to MV x rays is the characterization of the number and local complexity (clustering) of the initial DSB produced within a cell. For high LET ions, the spatial density of DSB induction along an ion's trajectory is much greater than along the path of a low LET electron, such as the secondary electrons produced by the megavoltage (MV) x rays used in conventional radiation therapy. The main aspects of the three models are introduced and the conceptual similarities and differences are critiqued and highlighted. Model predictions are compared in terms of the RBE for DSB induction and for reproductive cell survival. RESULTS AND CONCLUSIONS Comparisons of the RBE for DSB induction and for cell survival are presented for proton (1 H), helium (4 He), and carbon (12 C) ions for the therapeutically most relevant range of ion beam energies. The reviewed models embody mechanisms of action acting over the spatial scales underlying the biological processing of potentially lethal DSB into more lethal forms of damage. Differences among the number and types of input parameters, relevant biological targets, and the computational approaches among the LEM, MK and RMF models are summarized and critiqued. Potential experiments to test some of the seemingly contradictory aspects of the models are discussed.
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Affiliation(s)
- Robert D Stewart
- Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 356043, Seattle, WA, 98195, USA
| | - David J Carlson
- Department of Therapeutic Radiology, Yale University, New Haven, CT, USA
| | - Michael P Butkus
- Department of Therapeutic Radiology, Yale University, New Haven, CT, USA
| | - Roland Hawkins
- Radiation Oncology Center, Ochsner Clinic Foundation, New Orleans, LA, 70121, USA
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Fossati P, Matsufuji N, Kamada T, Karger CP. Radiobiological issues in prospective carbon ion therapy trials. Med Phys 2018; 45:e1096-e1110. [PMID: 30421806 DOI: 10.1002/mp.12506] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 05/29/2017] [Accepted: 07/26/2017] [Indexed: 12/15/2022] Open
Abstract
Carbon ion radiotherapy (CIRT) is developing toward a versatile tool in radiotherapy; however, the increased relative biological effectiveness (RBE) of carbon ions in tumors and normal tissues with respect to photon irradiation has to be considered by mathematical models in treatment planning. As a consequence, dose prescription and definition of dose constraints are performed in terms of RBE weighted rather than absorbed dose. The RBE is a complex quantity, which depends on physical variables, such as dose and beam quality as well as on normal tissue- or tumor-specific factors. At present, three RBE models are employed in CIRT: (a) the mixed-beam model, (b) the Microdosimetric Kinetic Model (MKM), and (c) the local effect model. While the LEM is used in Europe, the other two models are employed in Japan, and unfortunately, the concepts of how the nominal RBE-weighted dose is determined and prescribed differ significantly between the European and Japanese centers complicating the comparison, transfer, and reproduction of clinical results. This has severe impact on the way treatments should be prescribed, recorded, and reported. This contribution reviews the concept of the clinical application of the different RBE models and the ongoing clinical CIRT trials in Japan and Europe. Limitations of the RBE models and the resulting radiobiological issues in clinical CIRT trials are discussed in the context of current clinical evidence and future challenges.
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Affiliation(s)
- Piero Fossati
- Fondazione CNAO (Centro Nazionale di Adroterapia Oncologica), Pavia, Italy.,European Institute of Oncology, Milano, Italy
| | | | - Tadashi Kamada
- National Institute of Radiological Sciences, Chiba, Japan
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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Heavy Charged Particles: Does Improved Precision and Higher Biological Effectiveness Translate to Better Outcome in Patients? Semin Radiat Oncol 2018. [DOI: 10.1016/j.semradonc.2017.11.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Saager M, Peschke P, Brons S, Debus J, Karger CP. Determination of the proton RBE in the rat spinal cord: Is there an increase towards the end of the spread-out Bragg peak? Radiother Oncol 2018; 128:115-120. [PMID: 29573823 DOI: 10.1016/j.radonc.2018.03.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND AND PURPOSE To determine the relative biological effectiveness (RBE) of protons in the rat spinal cord as a function of linear energy transfer (LET) and dose. MATERIALS AND METHODS The rat cervical spinal cord was irradiated with single or two equal fractions (split doses) of protons at four positions (LET 1.4-5.5 keV/µm) along a 6 cm spread-out Bragg peak (SOBP). From dose-response analysis, TD50- (dose at 50% effect probability) and RBE-values were derived using the endpoint of radiation-induced myelopathy. RESULTS Along the SOBP, the TD50-values decreased from 21.7 ± 0.3 Gy to 19.5 ± 0.5 Gy for single and from 32.3 ± 0.3 Gy to 27.9 ± 0.5 Gy for split doses. The corresponding RBE-values increased from 1.13 ± 0.04 to 1.26 ± 0.05 (single doses) and from 1.06 ± 0.02 to 1.23 ± 0.03 (split doses). CONCLUSIONS For the relative high fractional doses, the experimental RBE at the distal edge of the proton SOBP is moderately increased. The conventionally applied RBE of 1.1 appears to be valid for the mid-SOBP region, but the higher values occurring more distally could be of clinical significance, especially if critical structures are located in this area. Further in vivo studies at lower fractional doses are urgently required.
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Affiliation(s)
- Maria Saager
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.
| | - Peter Peschke
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Stephan Brons
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Jürgen Debus
- Dept. of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Christian P Karger
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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17
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Gillmann C, Lomax AJ, Weber DC, Jäkel O, Karger CP. Dose-response curves for MRI-detected radiation-induced temporal lobe reactions in patients after proton and carbon ion therapy: Does the same RBE-weighted dose lead to the same biological effect? Radiother Oncol 2018; 128:109-114. [PMID: 29459152 DOI: 10.1016/j.radonc.2018.01.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 01/22/2018] [Accepted: 01/29/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE To derive the dose-response curve for temporal lobe reactions (TLRs) after proton therapy and to compare the resulting relative biological effectiveness (RBE)-weighted tolerance doses based on an RBE of 1.1 with published values for carbon ions, which were calculated by the two versions of the local effect model (LEM I or IV). METHODS AND MATERIALS 62 patients treated with protons for skull base tumors were analyzed for TLRs using magnetic resonance imaging. Within the mean follow-up time of 38 months, TLRs were observed in six patients. Dose-response curves based on the RBE-weighted maximum dose, excluding the 1 cm3-volume with the highest dose, were derived and compared to previously published dose-response curves for carbon ions, which were obtained using LEM I or IV, respectively. RESULTS The dose-response curves for protons and LEM I were found to be almost identical while the curve of LEM IV was shifted toward higher doses. The resulting tolerance doses at the 5% effect level were 68.2+2.7-5.6, 68.6+3.0-3.9 and 78.3+3.8-5.0 Gy (RBE), respectively. CONCLUSIONS The RBE-weighted dose prescription for protons leads to the same RBE-weighted dose-response curve for TLR as the one for LEM I-based carbon ions, while LEM IV predicts clinically significant higher tolerance doses.
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Affiliation(s)
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, PSI Villigen, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, PSI Villigen, Switzerland; Department of Radiation Oncology, University Hospital of Bern, Switzerland
| | - Oliver Jäkel
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Germany; Heidelberg Ion Beam Therapy Center (HIT), Heidelberg University Hospital, Germany
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Germany.
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Saager M, Peschke P, Welzel T, Huang L, Brons S, Grün R, Scholz M, Debus J, Karger CP. Late normal tissue response in the rat spinal cord after carbon ion irradiation. Radiat Oncol 2018; 13:5. [PMID: 29325596 PMCID: PMC5765675 DOI: 10.1186/s13014-017-0950-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/29/2017] [Indexed: 12/17/2022] Open
Abstract
Background The present work summarizes the research activities on radiation-induced late effects in the rat spinal cord carried out within the “clinical research group ion beam therapy” funded by the German Research Foundation (DFG, KFO 214). Methods and materials Dose–response curves for the endpoint radiation-induced myelopathy were determined at 6 different positions (LET 16–99 keV/μm) within a 6 cm spread-out Bragg peak using either 1, 2 or 6 fractions of carbon ions. Based on the tolerance dose TD50 of carbon ions and photons, the relative biological effectiveness (RBE) was determined and compared with predictions of the local effect model (LEM I and IV). Within a longitudinal magnetic resonance imaging (MRI)-based study the temporal development of radiation-induced changes in the spinal cord was characterized. To test the protective potential of the ACE (angiotensin converting enzyme)-inhibitor ramipril™, an additional dose–response experiment was performed. Results The RBE-values increased with LET and the increase was found to be larger for smaller fractional doses. Benchmarking the RBE-values as predicted by LEM I and LEM IV with the measured data revealed that LEM IV is more accurate in the high-LET, while LEM I is more accurate in the low-LET region. Characterization of the temporal development of radiation-induced changes with MRI demonstrated a shorter latency time for carbon ions, reflected on the histological level by an increased vessel perforation after carbon ion as compared to photon irradiations. For the ACE-inhibitor ramipril™, a mitigative rather than protective effect was found. Conclusions This comprehensive study established a large and consistent RBE data base for late effects in the rat spinal cord after carbon ion irradiation which will be further extended in ongoing studies. Using MRI, an extensive characterization of the temporal development of radiation-induced alterations was obtained. The reduced latency time for carbon ions is expected to originate from a dynamic interaction of various complex pathological processes. A dominant observation after carbon ion irradiation was an increase in vessel perforation preferentially in the white matter. To enable a targeted pharmacological intervention more details of the molecular pathways, responsible for the development of radiation-induced myelopathy are required.
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Affiliation(s)
- Maria Saager
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany. .,Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. .,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.
| | - Peter Peschke
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thomas Welzel
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Lifi Huang
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Stephan Brons
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
| | - Rebecca Grün
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Michael Scholz
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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Abstract
Carbon ion therapy is a promising evolving modality in radiotherapy to treat tumors that are radioresistant against photon treatments. As carbon ions are more effective in normal and tumor tissue, the relative biological effectiveness (RBE) has to be calculated by bio-mathematical models and has to be considered in the dose prescription. This review (i) introduces the concept of the RBE and its most important determinants, (ii) describes the physical and biological causes of the increased RBE for carbon ions, (iii) summarizes available RBE measurements in vitro and in vivo, and (iv) describes the concepts of the clinically applied RBE models (mixed beam model, local effect model, and microdosimetric-kinetic model), and (v) the way they are introduced into clinical application as well as (vi) their status of experimental and clinical validation, and finally (vii) summarizes the current status of the use of the RBE concept in carbon ion therapy and points out clinically relevant conclusions as well as open questions. The RBE concept has proven to be a valuable concept for dose prescription in carbon ion radiotherapy, however, different centers use different RBE models and therefore care has to be taken when transferring results from one center to another. Experimental studies significantly improve the understanding of the dependencies and limitations of RBE models in clinical application. For the future, further studies investigating quantitatively the differential effects between normal tissues and tumors are needed accompanied by clinical studies on effectiveness and toxicity.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany. Author to whom any correspondence should be addressed
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Grau C, Høyer M, Poulsen PR, Muren LP, Korreman SS, Tanderup K, Lindegaard JC, Alsner J, Overgaard J. Rethink radiotherapy - BIGART 2017. Acta Oncol 2017; 56:1341-1352. [PMID: 29148908 DOI: 10.1080/0284186x.2017.1371326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Cai Grau
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Morten Høyer
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Ludvig Paul Muren
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Kari Tanderup
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Jan Alsner
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Overgaard
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
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Müller J, Neubert C, von Neubeck C, Baumann M, Krause M, Enghardt W, Bütof R, Dietrich A, Lühr A. Proton radiography for inline treatment planning and positioning verification of small animals. Acta Oncol 2017; 56:1399-1405. [PMID: 28835182 DOI: 10.1080/0284186x.2017.1352102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION As proton therapy becomes increasingly well established, there is a need for high-quality clinically relevant in vivo data to gain better insight into the radiobiological effects of proton irradiation on both healthy and tumor tissue. This requires the development of easily applicable setups that allow for efficient, fractionated, image-guided proton irradiation of small animals, the most widely used pre-clinical model. MATERIAL AND METHODS Here, a method is proposed to perform dual-energy proton radiography for inline positioning verification and treatment planning. Dual-energy proton radiography exploits the differential enhancement of object features in two successively measured two-dimensional (2D) dose distributions at two different proton energies. The two raw images show structures that are dominated by energy absorption (absorption mode) or scattering (scattering mode) of protons in the object, respectively. Data post-processing allowed for the separation of both signal contributions in the respective images. The images were evaluated regarding recognizable object details and feasibility of rigid registration to acquired planar X-ray scans. RESULTS Robust, automated rigid registration of proton radiography and planar X-ray images in scattering mode could be reliably achieved with the animal bedding unit used as registration landmark. Distinguishable external and internal features of the imaged mouse included the outer body contour, the skull with substructures, the lung, abdominal structures and the hind legs. Image analysis based on the combined information of both imaging modes allowed image enhancement and calculation of 2D water-equivalent path length (WEPL) maps of the object along the beam direction. DISCUSSION Fractionated irradiation of exposed target volumes (e.g., subcutaneous tumor model or brain) can be realized with the suggested method being used for daily positioning and range determination. Robust registration of X-ray and proton radiography images allows for the irradiation of tumor entities that require conventional computed tomography (CT)-based planning, such as orthotopic lung or brain tumors, similar to conventional patient treatment.
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Affiliation(s)
- Johannes Müller
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
| | - Christian Neubert
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany
| | - Cläre von Neubeck
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Baumann
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Mechthild Krause
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Wolfgang Enghardt
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Rebecca Bütof
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Antje Dietrich
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin Lühr
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany
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Lühr A, von Neubeck C, Helmbrecht S, Baumann M, Enghardt W, Krause M. Modeling in vivo relative biological effectiveness in particle therapy for clinically relevant endpoints. Acta Oncol 2017; 56:1392-1398. [PMID: 28849720 DOI: 10.1080/0284186x.2017.1356468] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND The relative biological effectiveness (RBE) of particle therapy compared to photon radiotherapy is known to be variable but the exact dependencies are still subject to debate. In vitro data suggested that RBE is to a large extend independent of ion type if parametrized by the beam quality Q. This study analyzed the RBE dependence of pre-clinical data on late toxicity with an emphasis on the beam quality. MATERIAL AND METHODS Published pre-clinical RBE dose-response data of the spinal cord following one and two fractions of photon and carbon ion irradiation were compiled. The beam quality for each treatment condition was obtained from Monte Carlo simulations. The αp and βp parameters of the linear-quadratic (LQ) model for particle irradiation were determined from the pre-clinical data and was provided as a function of Q. An introduced model proposed αp to increase linearly with Q and βp to remain constant. RBE values predicted by the model were compared to the published data. RESULTS The αp parameter was highly correlated with Q (R2 = 0.96) with a linear slope of 0.019 Gy-1. No significant variation of βp with Q was found. RBE and Q were also highly correlated (R2 = 0.98) for one and two fractions. The (extrapolated) RBE at Q = 0 (theoretical photon limit) for one and two fractions was 1.22 and significantly larger than 1 (p = .004). The model reproduced the dependence of RBE on fractionation well. CONCLUSIONS Fraction dose and beam quality Q were sufficient to describe the RBE variability for a late toxicity model within a carbon ion treatment field. Assuming the independence of the identified RBE parameters on the ion type might suggest the translation of variable (pre-) clinical RBE data from carbon ion to proton therapy.
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Affiliation(s)
- Armin Lühr
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Cläre von Neubeck
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Helmbrecht
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
| | - Michael Baumann
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
| | - Wolfgang Enghardt
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Mechthild Krause
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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