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Gomà C, Henkner K, Jäkel O, Lorentini S, Magro G, Mirandola A, Placidi L, Togno M, Vidal M, Vilches-Freixas G, Wulff J, Safai S. ESTRO-EPTN radiation dosimetry guidelines for the acquisition of proton pencil beam modelling data. Phys Imaging Radiat Oncol 2024; 31:100621. [PMID: 39220113 PMCID: PMC11364130 DOI: 10.1016/j.phro.2024.100621] [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: 07/08/2024] [Revised: 08/01/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Proton therapy (PT) is an advancing radiotherapy modality increasingly integrated into clinical settings, transitioning from research facilities to hospital environments. A critical aspect of the commissioning of a proton pencil beam scanning delivery system is the acquisition of experimental beam data for accurate beam modelling within the treatment planning system (TPS). These guidelines describe in detail the acquisition of proton pencil beam modelling data. First, it outlines the intrinsic characteristics of a proton pencil beam-energy distribution, angular-spatial distribution and particle number. Then, it lists the input data typically requested by TPSs. Finally, it describes in detail the set of experimental measurements recommended for the acquisition of proton pencil beam modelling data-integrated depth-dose curves, spot maps in air, and reference dosimetry. The rigorous characterization of these beam parameters is essential for ensuring the safe and precise delivery of proton therapy treatments.
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Affiliation(s)
- Carles Gomà
- Institute of Cancer and Blood Diseases, Hospital Clínic Barcelona, Barcelona, Spain
- Translational Genomics and Targeted Therapies in Solid Tumors, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Catalan Health Service, Barcelona, Spain
| | - Katrin Henkner
- Heidelberg Ion Beam Therapy Center at the Heidelberg University Hospital, Heidelberg, Germany
| | - Oliver Jäkel
- Heidelberg Ion Beam Therapy Center at the Heidelberg University Hospital, Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefano Lorentini
- Medical Physics Department, Azienda Provinciale per i Servizi Sanitari (APSS), Trento, Italy
| | - Giuseppe Magro
- Medical Physics Unit, National Center for Oncological Hadrontherapy (CNAO), Pavia, Italy
| | - Alfredo Mirandola
- Medical Physics Unit, National Center for Oncological Hadrontherapy (CNAO), Pavia, Italy
| | - Lorenzo Placidi
- Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, Rome, Italy
| | - Michele Togno
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Marie Vidal
- Institut Méditerranéen de Protonthérapie - Centre Antoine Lacassagne, Nice, France
| | - Gloria Vilches-Freixas
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Jörg Wulff
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- University Hospital Essen, Essen, Germany
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
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Lohberger B, Barna S, Glänzer D, Eck N, Leithner A, Georg D. DNA-PKcs Inhibition Sensitizes Human Chondrosarcoma Cells to Carbon Ion Irradiation via Cell Cycle Arrest and Telomere Capping Disruption. Int J Mol Sci 2024; 25:6179. [PMID: 38892366 PMCID: PMC11173223 DOI: 10.3390/ijms25116179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/27/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
In order to overcome the resistance to radiotherapy in human chondrosarcoma cells, the prevention from efficient DNA repair with a combined treatment with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) inhibitor AZD7648 was explored for carbon ion (C-ion) as well as reference photon (X-ray) irradiation (IR) using gene expression analysis, flow cytometry, protein phosphorylation, and telomere length shortening. Proliferation markers and cell cycle distribution changed significantly after combined treatment, revealing a prominent G2/M arrest. The expression of the G2/M checkpoint genes cyclin B, CDK1, and WEE1 was significantly reduced by IR alone and the combined treatment. While IR alone showed no effects, additional AZD7648 treatment resulted in a dose-dependent reduction in AKT phosphorylation and an increase in Chk2 phosphorylation. Twenty-four hours after IR, the key genes of DNA repair mechanisms were reduced by the combined treatment, which led to impaired DNA repair and increased radiosensitivity. A time-dependent shortening of telomere length was observed in both cell lines after combined treatment with AZD7648 and 8 Gy X-ray/C-ion IR. Our data suggest that the inhibition of DNA-PKcs may increase sensitivity to X-rays and C-ion IR by impairing its functional role in DNA repair mechanisms and telomere end protection.
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Affiliation(s)
- Birgit Lohberger
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Sandra Barna
- Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; (S.B.); (D.G.)
- MedAustron-Ion Therapy Center, Viktor-Kaplan Strasse 2, 2700 Wiener Neustadt, Austria
| | - Dietmar Glänzer
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Nicole Eck
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Andreas Leithner
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; (S.B.); (D.G.)
- MedAustron-Ion Therapy Center, Viktor-Kaplan Strasse 2, 2700 Wiener Neustadt, Austria
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Wulff J, Paul A, Bäcker CM, Baumann KS, Esser JN, Koska B, Timmermann B, Verbeek NG, Bäumer C. Consistency of Faraday cup and ionization chamber dosimetry of proton fields and the role of nuclear interactions. Med Phys 2024; 51:2277-2292. [PMID: 37991110 DOI: 10.1002/mp.16819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND A Faraday cup (FC) facilitates a quite clean measurement of the proton fluence emerging from clinical spot-scanning nozzles with narrow pencil-beams. The utilization of FCs appears to be an attractive option for high dose rate delivery modes and the source models of Monte-Carlo (MC) dose engines. However, previous studies revealed discrepancies of 3%-6% between reference dosimetry with ionization chambers (ICs) and FC-based dosimetry. This has prevented the widespread use of FCs for dosimetry in proton therapy. PURPOSE The current study aims at bridging the gap between FC dosimetry and IC dosimetry of proton fields delivered with spot-scanning treatment heads. Particularly, a novel method to evaluate FC measurements is introduced. METHODS A consistency check is formulated, which makes use of the energy balance and the reciprocity theorem. The measurement data comprise central-axis depth distributions of the absorbed dose of quasi-monochromatic fields with a width of about 28.5 cm and FC measurements of the reciprocal fields with a single spot. These data are complemented by a look-up of energy-range tables, the average Q-value of transmutations, and the escape energy carried away by neutrons and photons. The latter data are computed by MC simulations, which in turn are validated with measurements of the distal dose tail and neutron out-of-field doses. For comparison, the conventional approach of FC evaluation is performed, which computes absorbed dose from the product of fluence and stopping power. The results from the FC measurements are compared with the standard dosimetry protocols and improved reference dosimetry methods. RESULTS The deviation between the conventional FC-based dosimetry and the IC-based one according to standard dosimetry protocols was -4.7 ( ± $\pm$ 3.3)% for a 100 MeV field and -3.6 ( ± $\pm$ 3.5)% for 200 MeV, thereby agreeing within the reported uncertainties. The deviations could be reduced to -4.0 ( ± $\pm$ 2.9)% and -3.0 ( ± $\pm$ 3.1)% by adopting state-of-the-art reference dosimetry methods. The alternative approach using the energy balance gave deviations of only -1.9% (100 MeV) and -2.6% (200 MeV) using state-of-the-art dosimetry. The standard uncertainty of this novel approach was estimated to be about 2%. CONCLUSIONS An alternative concept has been established to determine the absorbed dose of monoenergetic proton fields with an FC. It eliminates the strong dependence of the conventional FC-based approach on the MC simulation of the stopping-power and of the secondary ions, which according to the study at hand is the major contributor to the underestimation of the absorbed dose. Some contributions to the uncertainty of the novel approach could potentially be reduced in future studies. This would allow for accurate consistency tests of conventional dosimetry procedures.
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Affiliation(s)
- Jörg Wulff
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
| | - Anne Paul
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
- Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Claus Maximilian Bäcker
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
| | - Kilian-Simon Baumann
- Department of Radiotherapy and Radiation Oncology, Marburg University Hospital, Marburg, Germany
- Marburg Ion-Beam Therapy Center (MIT), Marburg, Germany
- University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen, Germany
| | - Johannes Niklas Esser
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
| | - Benjamin Koska
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
- Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Cancer Consortium (DKTK), Essen, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Nico Gerd Verbeek
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen, Essen, Germany
- University Hospital Essen, Essen, Germany
- West German Cancer Center (WTZ), Essen, Germany
- German Cancer Consortium (DKTK), Essen, Germany
- Department of Physics, Technische Universität Dortmund, Dortmund, Germany
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Verona C, Barna S, Georg D, Hamad Y, Magrin G, Marinelli M, Meouchi C, Verona Rinati G. Diamond based integrated detection system for dosimetric and microdosimetric characterization of radiotherapy ion beams. Med Phys 2024; 51:533-544. [PMID: 37656015 DOI: 10.1002/mp.16698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND Ion beam therapy allows for a substantial sparing of normal tissues and higher biological efficacy. Synthetic single crystal diamond is a very good material to produce high-spatial-resolution and highly radiation hard detectors for both dosimetry and microdosimetry in ion beam therapy. PURPOSE The aim of this work is the design, fabrication and test of an integrated waterproof detector based on synthetic single crystal diamond able to simultaneously perform dosimetric and microdosimetric characterization of clinical ion beams. METHODS The active elements of the integrated diamond device, that is, dosimeter and microdosimeter, were both realized in a Schottky diode configuration featured by different area, thickness, and shape by means of photolithography technologies for the selective growth of intrinsic and boron-doped CVD diamond. The cross-section of the sensitive volume of the dosimetric element is 4 mm2 and 1 μm-thick, while the microdosimetric one has an active cross-sectional area of 100 × 100 μm2 and a thickness of about 6.2 μm. The dosimetric and microdosimetric performance of the developed device was assessed at different depths in a water phantom at the MedAustron ion beam therapy facility using a monoenergetic uniformly scanned carbon ion beam of 284.7 MeV/u and proton beam of 148.7 MeV. The particle flux in the region of the microdosimeter was 6·107 cm2 /s for both irradiation fields. At each depth, dose and dose distributions in lineal energy were measured simultaneously and the dose mean lineal energy values were then calculated. Monte Carlo simulations were also carried out by using the GATE-Geant4 code to evaluate the relative dose, dose averaged linear energy transfer (LETd ), and microdosimetric spectra at various depths in water for the radiation fields used, by considering the contribution from the secondary particles generated in the ion interaction processes as well. RESULTS Dosimetric and microdosimetric quantities were measured by the developed prototype with relatively low noise (∼2 keV/μm). A good agreement between the measured and simulated dose profiles was found, with discrepancies in the peak to plateau ratio of about 3% and 4% for proton and carbon ion beams respectively, showing a negligible LET dependence of the dosimetric element of the device. The microdosimetric spectra were validated with Monte Carlo simulations and a good agreement between the spectra shapes and positions was found. Dose mean lineal energy values were found to be in close agreement with those reported in the literature for clinical ion beams, showing a sharp increase along the Bragg curve, being also consistent with the calculated LETd for all depths within the experimental error of 10%. CONCLUSIONS The experimental indicate that the proposed device can allow enhanced dosimetry in particle therapy centers, where the absorbed dose measurement is implemented by the microdosimetric characterization of the radiation field, thus providing complementary results. In addition, the proposed device allows for the reduction of the experimental uncertainties associated with detector positioning and could facilitate the partial overcoming of some drawbacks related to the low sensitivity of diamond microdosimeters to low LET radiation.
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Affiliation(s)
- Claudio Verona
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata", Sez. INFN-Roma2, Roma, Italia, Italy
| | - Sandra Barna
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Yasmin Hamad
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Giulio Magrin
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Marco Marinelli
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata", Sez. INFN-Roma2, Roma, Italia, Italy
| | - Cynthia Meouchi
- Institute of Atomic and Subatomic Physics, Vienna University of Technology, Vienna, Austria
| | - Gianluca Verona Rinati
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata", Sez. INFN-Roma2, Roma, Italia, Italy
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Etschmaier V, Glänzer D, Eck N, Schäfer U, Leithner A, Georg D, Lohberger B. Proton and Carbon Ion Irradiation Changes the Process of Endochondral Ossification in an Ex Vivo Femur Organotypic Culture Model. Cells 2023; 12:2301. [PMID: 37759523 PMCID: PMC10527791 DOI: 10.3390/cells12182301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Particle therapy (PT) that utilizes protons and carbon ions offers a promising way to reduce the side effects of radiation oncology, especially in pediatric patients. To investigate the influence of PT on growing bone, we exposed an organotypic rat ex vivo femur culture model to PT. After irradiation, histological staining, immunohistochemical staining, and gene expression analysis were conducted following 1 or 14 days of in vitro culture (DIV). Our data indicated a significant loss of proliferating chondrocytes at 1 DIV, which was followed by regeneration attempts through chondrocytic cluster formation at 14 DIV. Accelerated levels of mineralization were observed, which correlated with increased proteoglycan production and secretion into the pericellular matrix. Col2α1 expression, which increased during the cultivation period, was significantly inhibited by PT. Additionally, the decrease in ColX expression over time was more pronounced compared to the non-IR control. The chondrogenic markers BMP2, RUNX2, OPG, and the osteogenic marker ALPL, showed a significant reduction in the increase in expression after 14 DIV due to PT treatment. It was noted that carbon ions had a stronger influence than protons. Our bone model demonstrated the occurrence of pathological and regenerative processes induced by PT, thus building on the current understanding of the biological mechanisms of bone.
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Affiliation(s)
- Vanessa Etschmaier
- Department of Orthopaedics and Trauma, Medical University Graz, 8036 Graz, Austria; (V.E.); (D.G.); (N.E.); (A.L.)
| | - Dietmar Glänzer
- Department of Orthopaedics and Trauma, Medical University Graz, 8036 Graz, Austria; (V.E.); (D.G.); (N.E.); (A.L.)
| | - Nicole Eck
- Department of Orthopaedics and Trauma, Medical University Graz, 8036 Graz, Austria; (V.E.); (D.G.); (N.E.); (A.L.)
| | - Ute Schäfer
- Department of Neurosurgery, Research Unit for Experimental Neurotraumatology, Medical University of Graz, 8036 Graz, Austria;
| | - Andreas Leithner
- Department of Orthopaedics and Trauma, Medical University Graz, 8036 Graz, Austria; (V.E.); (D.G.); (N.E.); (A.L.)
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, 1090 Vienna, Austria;
- MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria
| | - Birgit Lohberger
- Department of Orthopaedics and Trauma, Medical University Graz, 8036 Graz, Austria; (V.E.); (D.G.); (N.E.); (A.L.)
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Fuchs H, Padilla-Cabal F, Oborn BM, Georg D. Commissioning a beam line for MR-guided particle therapy assisted by in silico methods. Med Phys 2023; 50:1019-1028. [PMID: 36504399 DOI: 10.1002/mp.16143] [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: 06/29/2022] [Revised: 10/11/2022] [Accepted: 11/16/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Radiation therapy is continuously moving towards more precise dose delivery. The combination of online MR imaging and particle therapy, for example, radiation therapy using protons or carbon ions, could enable the next level of precision in radiotherapy. In particle therapy, research towards a combination of MR and particle therapy is well underway, but still far from clinical systems. The combination of high magnetic fields with particle therapy delivery poses several challenges for treatment planning, treatment workflow, dose delivery, and dosimetry. PURPOSE To present a workflow for commissioning of a light ion beam line with an integrated dipole magnet to perform MR-guided particle therapy (MRgPT) research, producing not only basic beam data but also magnetic field maps for accurate dose calculation. Accurate dose calculation in magnetic field environments requires high-quality magnetic field maps to compensate for magnetic-field-dependent trajectory changes and dose perturbations. METHODS The research beam line at MedAustron was coupled with a resistive dipole magnet positioned at the isocenter. Beam data were measured for proton and carbon ions with and without an applied magnetic field of 1 T. Laterally integrated depth-dose curves (IDC) as well as beam profiles were measured in water while beam trajectories were measured in air. Based on manufacturer data, an in silico model of the magnet was created, allowing to extract high-quality 3D magnetic field data. An existing GATE/Geant4 Monte Carlo (MC) model of the beam line was extended with the generated magnetic field data and benchmarked against experimental data. RESULTS A 3D magnetic field volume covering fringe fields until 50 mT was found to be sufficient for an accurate beam trajectory modeling. The effect on particle range retraction was found to be 2.3 and 0.3 mm for protons and carbon ions, respectively. Measured lateral beam offsets in water agreed within 0.4 and -0.5 mm with MC simulations for protons and carbon ions, respectively. Experimentally determined in-air beam trajectories agreed within 0.4 mm in the homogeneous magnetic field area. CONCLUSION The presented approach based on in silico modeling and measurements allows to commission a beam line for MRgPT while providing benchmarking data for the magnetic field modeling, required for state-of-the art dose calculation methods.
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Affiliation(s)
- Hermann Fuchs
- Division of Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna, Wien, Austria.,MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Fatima Padilla-Cabal
- Division of Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Bradley M Oborn
- Institute of Radiooncology-OncoRay, Radiooncology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, NSW, Australia
| | - Dietmar Georg
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria.,Division of Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
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Lohberger B, Glänzer D, Eck N, Stasny K, Falkner A, Leithner A, Georg D. The ATR Inhibitor VE-821 Enhances the Radiosensitivity and Suppresses DNA Repair Mechanisms of Human Chondrosarcoma Cells. Int J Mol Sci 2023; 24:2315. [PMID: 36768638 PMCID: PMC9917087 DOI: 10.3390/ijms24032315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
To overcome the resistance to radiotherapy in chondrosarcomas, the prevention of efficient DNA repair with an additional treatment was explored for particle beams as well as reference X-ray irradiation. The combined treatment with DNA repair inhibitors-with a focus on ATRi VE-821-and proton or carbon ions irradiation was investigated regarding cell viability, proliferation, cell cycle distribution, MAPK phosphorylation, and the expression of key DNA repair genes in two human chondrosarcoma cell lines. Pre-treatment with the PARPis Olaparib or Veliparib, the ATMi Ku-55933, and the ATRi VE-821 resulted in a dose-dependent reduction in viability, whereas VE-821 has the most efficient response. Quantification of γH2AX phosphorylation and protein expression of the DNA repair pathways showed a reduced regenerative capacity after irradiation. Furthermore, combined treatment with VE-821 and particle irradiation increased MAPK phosphorylation and the expression of apoptosis markers. At the gene expression and at the protein expression/phosphorylation level, we were able to demonstrate the preservation of DNA damage after combined treatment. The present data showed that the combined treatment with ATMi VE-821 increases the radiosensitivity of human chondrosarcoma cells in vitro and significantly suppresses efficient DNA repair mechanisms, thus improving the efficiency of radiotherapy.
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Affiliation(s)
- Birgit Lohberger
- Department of Orthopedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Dietmar Glänzer
- Department of Orthopedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Nicole Eck
- Department of Orthopedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | | | - Anna Falkner
- MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria
| | - Andreas Leithner
- Department of Orthopedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Dietmar Georg
- MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria
- Department of Radiation Oncology, Medical University of Vienna, 1090 Vienna, Austria
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8
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Thien TC, Nemallapudi MV, Hsieh CW, Chen AE. Uniformity calibration for large area XY strip parallel plate ionization chamber. Phys Med Biol 2022; 68. [PMID: 36562587 DOI: 10.1088/1361-6560/aca9b5] [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: 05/10/2022] [Accepted: 12/07/2022] [Indexed: 12/12/2022]
Abstract
Demand for large area parallel plate ionization chamber (PPIC) or large area ionization chamber (LAIC) has risen in recent years due to several advantages of the large effective area in monitoring therapeutic radiation beams. PPICs are designed for the measurements of beam profile and dosimetry in radiation therapy quality assurance (QA) procedures.Objective. Heterogeneous responses over the large sensitive area pose an undeniable concern for the straightforward applications of PPICs in clinical dosimetry. Uniformity calibration for the detector response is thus essential for the accurate performance of each PPIC unit.Approach.A large area XY strip PPIC, characterized by a large effective area of 345.44 × 345.44 mm2and 256 readout channels, was investigated in this study. A new systematic uniformity calibration is developed to improve the lateral response of the PPIC over the measurements for both narrow beams and large square field beams. A 2D response map of the PPIC was obtained by a spot-scanning method using a compact x-ray tube (mini x-ray). The mini x-ray, providing stable radiation (uncertainty <0.1%), was moved with a step size of 20 mm in 2 dimensions across the entire PPIC surface to collect a complete spot scan. Different uniformity calibration methods were introduced for the measurement of the PPIC by adopting the information from the detector 2D response map.Main results.Deviation of the detector response, before calibration, was observed to reach about 7% for the testing PPIC unit which is much higher than the recommended uniformity response of 1% (IAEA TRS-398). The uniformity response of the PPIC improved significantly to less than 1% across the detector surface after calibration.Significance.The proposed methods enable the practical application of PPIC in routine clinical dosimetry and can be reliably adopted by any radiation facility to perform daily and monthly QA.
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Affiliation(s)
- T C Thien
- Department of Physics, National Central University, Taiwan.,Institute of Physics, Academia Sinica, Taiwan
| | | | - C W Hsieh
- Electrical Engineering, National Chiayi University, Taiwan
| | - A E Chen
- Department of Physics, National Central University, Taiwan
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Azcona JD, Aguilar B, Perales Á, Polo R, Zucca D, Irazola L, Viñals A, Cabello P, Delgado JM, Pedrero D, Bermúdez R, Fayos-Solá R, Huesa-Berral C, Burguete J. Commissioning of a synchrotron-based proton beam therapy system for use with a Monte Carlo treatment planning system. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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10
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Lohberger B, Barna S, Glänzer D, Eck N, Kerschbaum-Gruber S, Stasny K, Leithner A, Georg D. Cellular and Molecular Biological Alterations after Photon, Proton, and Carbon Ions Irradiation in Human Chondrosarcoma Cells Linked with High-Quality Physics Data. Int J Mol Sci 2022; 23:11464. [PMID: 36232764 PMCID: PMC9569755 DOI: 10.3390/ijms231911464] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/08/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
Chondrosarcomas are particularly difficult to treat due to their resistance to chemotherapy and radiotherapy. However, particle therapy can enhance local control and patient survival rates. To improve our understanding of the basic cellular radiation response, as a function of dose and linear energy transfer (LET), we developed a novel water phantom-based setup for cell culture experiments and characterized it dosimetrically. In a direct comparison, human chondrosarcoma cell lines were analyzed with regard to their viability, cell proliferation, cell cycle, and DNA repair behavior after irradiation with X-ray, proton, and carbon ions. Our results clearly showed that cell viability and proliferation were inhibited according to the increasing ionization density, i.e., LET, of the irradiation modes. Furthermore, a prominent G2/M arrest was shown. Gene expression profiling proved the upregulation of the senescence genes CDKN1A (p21), CDKN2A (p16NK4a), BMI1, and FOXO4 after particle irradiation. Both proton or C-ion irradiation caused a positive regulation of the repair genes ATM, NBN, ATXR, and XPC, and a highly significant increase in XRCC1/2/3, ERCC1, XPC, and PCNA expression, with C-ions appearing to activate DNA repair mechanisms more effectively. The link between the physical data and the cellular responses is an important contribution to the improvement of the treatment system.
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Affiliation(s)
- Birgit Lohberger
- Department of Orthopaedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Sandra Barna
- Department of Radiation Oncology, Medical University of Vienna, 1090 Vienna, Austria
| | - Dietmar Glänzer
- Department of Orthopaedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Nicole Eck
- Department of Orthopaedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | | | | | - Andreas Leithner
- Department of Orthopaedics and Trauma, Medical University of Graz, 8036 Graz, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, 1090 Vienna, Austria
- MedAustron Ion Therapy Center, 2700 Wiener Neustadt, Austria
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11
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Dose-Area Product Determination and Beam Monitor Calibration for the Fixed Beam of the Shanghai Advanced Proton Therapy Facility. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Research conducted to-date, makes use of the IBA-Lynx scintillating screen and radiochromic film to analyze the proton field uniformity for dose-area product (DAP) determination. In this paper, the machine log file based reconstruction is proposed to calculate the field uniformity to simplify the measurement. In order to calculate the field uniformity, the dose distribution is reconstructed based on the machine log file with matRad (an open source software for analytical dose calculation in MATLAB). After acquisition of the dose distribution, the field flatness and symmetry are calculated automatically for different proton energies. A comprehensive comparison of DAP determined with Bragg peak chamber (BPC) and Markus chamber (MC) is presented. The actual delivered dose is reconstructed with the log file to analyze the lateral dose distribution of the scanned field. DAP of different energies are calculated ranging from 70.6 MeV to 235 MeV. The percentage difference is calculated, illustrating the DAP discrepancy between the MC and BPC to the mean value. The percentage difference ranges from −0.19% to 1.26%. The variation between DAP measured with the BPC and MC peaks at −2.5%. The log file based reconstruction to calculate field uniformity can be an alternative for DAP determination. The direct method using a large-area Bragg peak chamber is investigated. The two methods to determine DAP and calibrate beam monitor illustrate consistent results.
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12
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Mirandola A, Maestri D, Magro G, Mastella E, Molinelli S, Rossi E, Russo S, Vai A, Ciocca M. Determination of ion recombination and polarity effects for the PTW Advanced Markus ionization chamber in synchrotron based scanned proton and carbon ion beams. Phys Med 2022; 96:149-156. [DOI: 10.1016/j.ejmp.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/09/2022] [Indexed: 10/18/2022] Open
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13
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Kuess P, Lechner W, Georg D, Palmans H. Reply to comment on 'Lateral response heterogeneity of Bragg peak ionization chambers for narrow-beam photon and proton dosimetry'. Phys Med Biol 2021; 66. [PMID: 34341187 DOI: 10.1088/1361-6560/ac16bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 07/21/2021] [Indexed: 11/12/2022]
Abstract
Gomà (2020Phys. Med. Biol.) commented on our paper 'Lateral response heterogeneity of Bragg peak ionization chambers for narrow-beam photon and proton dosimetry' (Kuesset al2017Phys. Med. Biol.629189-206) which describes a method to determine the response pattern of large-area ionization chambers using a collimated x-ray beam. Gomà performed a simple Monte Carlo simulation to investigate the energy transferred by secondary electrons within the detector, deducing that our conclusion, that the chamber has a non-uniform response, is not supported by our results. We appreciate the work performed by Gomà very much and believe that the transport of secondary electrons in the chamber is an important contribution to understand the non-uniformity response of large-area chambers in narrow beams. However, we disagree with the conclusions drawn by Gomà that the radial response is homogenous. His simulation actually demonstrates that the response is non-uniform in an x-ray beam.
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Affiliation(s)
- Peter Kuess
- Department of Radiation Oncology, Division Medical Physics, Medical University Vienna, Vienna, Austria
| | - Wolfgang Lechner
- Department of Radiation Oncology, Division Medical Physics, Medical University Vienna, Vienna, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Division Medical Physics, Medical University Vienna, Vienna, Austria
| | - Hugo Palmans
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria.,National Physics Laboratory, Teddington TW 11 0LW, United Kingdom
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14
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Gomà C. Comment on 'Lateral response heterogeneity of Bragg peak ionization chambers for narrow-beam photon and proton dosimetry'. Phys Med Biol 2021; 66. [PMID: 34341186 DOI: 10.1088/1361-6560/ac16bb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 07/21/2021] [Indexed: 11/12/2022]
Abstract
Kuesset al(2017Phys. Med. Biol.62206-27) irradiated several PTW 34070 ionization chambers with a narrow x-ray beam impinging at different positions of the detector entrance window and they observed that the reading of the ionization chambers decreased as the impact point of the beam approached the edge of the sensitive volume. They concluded that the radial response of the detector decreased with increasing radius and they proposed a correction factor to correct for that effect. This work shows, by means of a simple Monte Carlo simulation, that the conclusions of Kuess and co-workers do not seem to be supported by their experimental findings-quite the opposite, their experimental results seem to be compatible with a rather homogeneous radial response of the PTW 34070. It is shown that the radial decrease in the ionization chamber reading (as the impact point of the beam approaches the edge of the sensitive volume) is not due to a radial decrease of the response, but to the fact that part of the energy transferred to the secondary electrons is carried away and deposited outside the sensitive volume of the ionization chamber. As a consequence, it is believed that the method and correction factors proposed by Kuess and colleagues are not suitable to assess the response uniformity of large-area ionization chambers. Furthermore, the results of the publications that have used them thus far should be thoroughly revised.
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Affiliation(s)
- Carles Gomà
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
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15
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Niemelä J, Partanen M, Ojala J, Kapanen M, Keyriläinen J. Dose-area product ratio in external small-beam radiotherapy: beam shape, size and energy dependencies in clinical photon beams. Biomed Phys Eng Express 2021; 7. [PMID: 33836522 DOI: 10.1088/2057-1976/abf6aa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/09/2021] [Indexed: 11/12/2022]
Abstract
In small-field radiotherapy (RT), a significant challenge is to define the amount of radiation dose absorbed in the patient where the quality of the beam has to be measured with high accuracy. The properties of a proposed new beam quality specifier, namely the dose-area-product ratio at 20 and 10 cm depths in water or DAPR20,10, were studied to yield more information on its feasibility over the conventional quality specifier tissue-phantom ratio or TPR20,10. The DAPR20,10may be measured with a large-area ionization chamber (LAC) instead of small volume chambers or semi-conductors where detector, beam and water phantom positioning and beam perturbations introduce uncertainties. The effects of beam shape, size and energy on the DAPR20,10were studied and it was shown that the DAPR20,10increases with increasing beam energy similarly to TPR20,10but in contrast exhibits a small beam size and shape dependence. The beam profile outside the beam limiting devices has been shown to have a large contribution to the DAPR20,10. There is potential in large area chambers to be used in DAPR measurement and its use in dosimetry of small-beam RT for beam quality measurements.
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Affiliation(s)
- Jarkko Niemelä
- University of Turku, Department of Physics and Astronomy, FI-20014 Turku, Finland.,Department of Medical Physics, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland.,Department of Oncology and Radiotherapy, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland
| | - Mari Partanen
- Department of Oncology, Unit of Radiotherapy, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland.,Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland
| | - Jarkko Ojala
- Department of Oncology, Unit of Radiotherapy, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland.,Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland
| | - Mika Kapanen
- Department of Oncology, Unit of Radiotherapy, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland.,Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland
| | - Jani Keyriläinen
- Department of Medical Physics, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland.,Department of Oncology and Radiotherapy, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland
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16
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Fuchs H, Padilla‐Cabal F, Zimmermann L, Palmans H, Georg D. MR-guided proton therapy: Impact of magnetic fields on the detector response. Med Phys 2021; 48:2572-2579. [PMID: 33326614 PMCID: PMC8251909 DOI: 10.1002/mp.14660] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate the response of detectors for proton dosimetry in the presence of magnetic fields. MATERIAL AND METHODS Four ionization chambers (ICs), two thimble-type and two plane-parallel-type, and a diamond detector were investigated. All detectors were irradiated with homogeneous single-energy-layer fields, using 252.7 MeV proton beams. A Farmer IC was additionally irradiated in the same geometrical configuration, but with a lower nominal energy of 97.4 MeV. The beams were subjected to magnetic field strengths of 0, 0.25, 0.5, 0.75, and 1 T produced by a research dipole magnet placed at the room's isocenter. Detectors were positioned at 2 cm water equivalent depth, with their stem perpendicular to both the magnetic field lines and the proton beam's central axis, in the direction of the Lorentz force. Normality and two sample statistical Student's t tests were performed to assess the influence of the magnetic field on the detectors' responses. RESULTS For all detectors, a small but significant magnetic field-dependent change of their response was found. Observed differences compared to the no magnetic field case ranged from +0.5% to -0.7%. The magnetic field dependence was found to be nonlinear and highest between 0.25 and 0.5 T for 252.7 MeV proton beams. A different variation of the Farmer chamber response with magnetic field strength was observed for irradiations using lower energy (97.4 MeV) protons. The largest magnetic field effects were observed for plane-parallel ionization chambers. CONCLUSION Small magnetic field-dependent changes in the detector response were identified, which should be corrected for dosimetric applications.
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Affiliation(s)
- Hermann Fuchs
- Division of Medical PhysicsDepartment of Radiation OncologyMedical University of Vienna1090ViennaAustria
- Division of Medical PhysicsMedAustron Ion Therapy Center2700Wiener NeustadtAustria
| | - Fatima Padilla‐Cabal
- Division of Medical PhysicsDepartment of Radiation OncologyMedical University of Vienna1090ViennaAustria
| | - Lukas Zimmermann
- Division of Medical PhysicsDepartment of Radiation OncologyMedical University of Vienna1090ViennaAustria
| | - Hugo Palmans
- Division of Medical PhysicsMedAustron Ion Therapy Center2700Wiener NeustadtAustria
- National Physical LaboratoryTW11 0LWTeddingtonUnited Kingdom
| | - Dietmar Georg
- Division of Medical PhysicsDepartment of Radiation OncologyMedical University of Vienna1090ViennaAustria
- Division of Medical PhysicsMedAustron Ion Therapy Center2700Wiener NeustadtAustria
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17
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Verbeek N, Wulff J, Bäumer C, Smyczek S, Timmermann B, Brualla L. Single pencil beam benchmark of a module for Monte Carlo simulation of proton transport in the PENELOPE code. Med Phys 2020; 48:456-476. [PMID: 33217026 DOI: 10.1002/mp.14598] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND AND PURPOSE PENH is a recently coded module for simulation of proton transport in conjunction with the Monte Carlo code PENELOPE. PENELOPE applies class II simulation to all type of interactions, in particular, to elastic collisions. PENH uses calculated differential cross sections for proton elastic collisions that include electron screening effects as well as nuclear structure effects. Proton-induced nuclear reactions are simulated from information in the ENDF-6 database or from alternative nuclear databases in ENDF format. The purpose of this work is to benchmark this module by simulating absorbed dose distributions from a single finite spot size proton pencil beam in water. MATERIALS AND METHODS Monte Carlo simulations with PENH are compared with simulation results from TOPAS Monte Carlo (v3.1p2) and RayStation Monte Carlo (v6). Different beam models are examined in terms of mean energy and energy spread to match the measured profiles. The phase-space file is derived from experimental measurements. Simulated absorbed dose distributions are compared to experimental data obtained with the ionization chamber array MatriXX 2D detector (IBA Dosimetry) in a water tank. The experiments were conducted with a clinical IBA pencil beam scanning dedicated nozzle. In all simulations a Fermi-Eyges phase-space representation of a single finite spot size proton pencil beam is used. RESULTS In general, there is a good agreement between simulated results and experimental data up to a distance of 3 cm from the central axis. In the core region (region where the dose is more than 10% of the maximum dose) PENH shows, overall, the smallest deviations from experimental data, with the largest radial rms (root mean square) smaller than 0.2. The results achieved by TOPAS and RayStation in that region are very close to those of PENH. For the halo region, that is the area of the dose distribution outside the core region reaching down to 0.01% of the maximum intensity, the largest rms achieved by TOPAS is always smaller than 0.5, yielding better results than the rest of the codes. CONCLUSION The physics modeling of the PENELOPE/PENH code yields results consistent with measurements in the dose range relevant for proton therapy. The discrepancies between PENH appearing at distances larger than 3 cm from the central-beam axis are accountable to the lack of neutron simulation in this code. In contradistinction, TOPAS has a better agreement with experimental data at large distances from the central-beam axis because of the simulation of neutrons.
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Affiliation(s)
- Nico Verbeek
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany
| | - Jörg Wulff
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany.,Radiation Oncology and Imaging, German Cancer Consortium DKTK, Heidelberg, Germany.,Technische Universität Dortmund, Otto-Hahn-Str. 4a, Dortmund, 44227, Germany
| | - Sabrina Smyczek
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany.,Faculty of Physics, Heinrich Heine University Düsseldorf HHU, Düsseldorf, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany.,Radiation Oncology and Imaging, German Cancer Consortium DKTK, Heidelberg, Germany.,Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Lorenzo Brualla
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.,University Hospital Essen, West German Cancer Center WTZ, Essen, Germany
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18
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Kuess P, Haupt S, Osorio J, Grevillot L, Fuchs H, Georg D, Palmans H. Characterization of the PTW-34089 type 147 mm diameter large-area ionization chamber for use in light-ion beams. ACTA ACUST UNITED AC 2020; 65:17NT02. [DOI: 10.1088/1361-6560/ab9852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Beam monitor calibration of a synchrotron-based scanned light-ion beam delivery system. Z Med Phys 2020; 31:154-165. [PMID: 32747175 DOI: 10.1016/j.zemedi.2020.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/20/2020] [Accepted: 06/15/2020] [Indexed: 11/23/2022]
Abstract
PURPOSE This paper presents the implementation and comparison of two independent methods of beam monitor calibration in terms of number of particles for scanned proton and carbon ion beams. METHODS In the first method, called the single-layer method, dose-area-product to water (DAPw) is derived from the absorbed dose to water determined using a Roos-type plane-parallel ionization chamber in single-energy scanned beams. This is considered the reference method for the beam monitor calibration in the clinically relevant proton and carbon energy ranges. In the second method, called the single-spot method, DAPw of a single central spot is determined using a Bragg-peak (BP) type large-area plane-parallel ionization chamber. Emphasis is given to the detailed characterization of the ionization chambers used for the beam monitor calibration. For both methods a detailed uncertainty budget on the DAPw determination is provided as well as on the derivation of the number of particles. RESULTS Both calibration methods agreed on average within 1.1% for protons and within 2.6% for carbon ions. The uncertainty on DAPw using single-layer beams is 2.1% for protons and 3.1% for carbon ions with major contributions from the available values of kQ and the average spot spacing in both lateral directions. The uncertainty using the single-spot method is 2.2% for protons and 3.2% for carbon ions with major contributions from the available values of kQ and the non-uniformity of the BP chamber response, which can lead to a correction of up-to 3.2%. For the number of particles, an additional dominant uncertainty component for the mean stopping power per incident proton (or the CEMA) needs to be added. CONCLUSION The agreement between both methods enhances confidence in the beam monitor calibration and the estimated uncertainty. The single-layer method can be used as a reference and the single-spot method is an alternative that, when more accumulated knowledge and data on the method becomes available, can be used as a redundant dose monitor calibration method. This work, together with the overview of information from the literature provided here, is a first step towards comprehensive information on the single-spot method.
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20
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Renaud J, Palmans H, Sarfehnia A, Seuntjens J. Absorbed dose calorimetry. ACTA ACUST UNITED AC 2020; 65:05TR02. [DOI: 10.1088/1361-6560/ab4f29] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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21
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Grevillot L, Osorio Moreno J, Letellier V, Dreindl R, Elia A, Fuchs H, Carlino A, Kragl G, Palmans H, Vatnitsky S, Stock M. Clinical implementation and commissioning of the MedAustron Particle Therapy Accelerator for non‐isocentric scanned proton beam treatments. Med Phys 2019; 47:380-392. [DOI: 10.1002/mp.13928] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/01/2019] [Accepted: 11/11/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- Loïc Grevillot
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | | | - Virgile Letellier
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | - Ralf Dreindl
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | - Alessio Elia
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | - Hermann Fuchs
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
- Department of Radiation Therapy Medical University of Vienna/AKH Vienna Vienna Austria
| | - Antonio Carlino
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | - Gabriele Kragl
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
| | - Hugo Palmans
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
- National Physical Laboratory Hampton Road TW11 0LW Teddington UK
| | | | - Markus Stock
- EBG MedAustron GmbH Marie Curie‐Straße 5 A‐2700 Wiener Neustadt Austria
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Shen J, Ding X, Hu Y, Kang Y, Liu W, Deng W, Bues M. Technical Note: Comprehensive evaluation and implementation of two independent methods for beam monitor calibration for proton scanning beam. Med Phys 2019; 46:5867-5875. [DOI: 10.1002/mp.13866] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/29/2019] [Accepted: 10/10/2019] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jiajian Shen
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Xiaoning Ding
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Yanle Hu
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Yixiu Kang
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Wei Liu
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Wei Deng
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
| | - Martin Bues
- Department of Radiation Oncology Mayo Clinic Phoenix AZ 85054USA
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23
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Shen J. Comment on ‘Lateral response heterogeneity of Bragg peak ionization chambers for narrow-beam photon and proton dosimetry’. ACTA ACUST UNITED AC 2019; 64:198001. [DOI: 10.1088/1361-6560/ab3b97] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Kuess P, Böhlen TT, Lechner W, Elia A, Georg D, Palmans H. Reply to Comment on ‘Lateral response heterogeneity of Bragg peak ionization chambers for narrow-beam photon and proton dosimetry’. ACTA ACUST UNITED AC 2019; 64:198002. [DOI: 10.1088/1361-6560/ab3ba0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Mirandola A, Magro G, Maestri D, Mairani A, Mastella E, Molinelli S, Russo S, Vai A, Ciocca M. Determination of ion recombination and polarity effect correction factors for a plane-parallel ionization Bragg peak chamber under proton and carbon ion pencil beams. Phys Med Biol 2019; 64:095010. [PMID: 30844771 DOI: 10.1088/1361-6560/ab0db4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Within the dosimetric characterization of particle beams, laterally-integrated depth-dose-distributions (IDDs) are measured and provided to the treatment planning system (TPS) for beam modeling or used as a benchmark for Monte Carlo (MC) simulations. The purpose of this work is the evaluation, in terms of ion recombination and polarity effect, of the dosimetric correction to be applied to proton and carbon ion curves as a function of linear energy transfer (LET). LET was calculated with a MC code for selected IDDs. Several regions of Bragg peak (BP) curve were investigated. The charge was measured with the plane-parallel BP-ionization chamber mounted in the Peakfinder as a field detector, by delivering a fixed number of particles at the maximum flux. The dose rate dependence was evaluated for different flux levels. The chamber was connected to an electrometer and exposed to un-scanned pencil beams. For each measurement the chamber was supplied with {±400, +200, +100} V. Recombination and polarity correction factors were then calculated as a function of depth and LET in water. Three energies representative of the clinical range were investigated for both particle types. The corrected IDDs (IDD k s) were then compared against MC. Recombination correction factors were LET and energy dependent, ranging from 1.000 to 1.040 (±0.5%) for carbon ions, while nearly negligible for protons. Moreover, no corrections need to be applied due to polarity effect being <0.5% along the whole IDDs for both particle types. IDD k s showed a better agreement than uncorrected curves when compared to MC, with a reduction of the mean absolute variation from 1.2% to 0.9%. The aforementioned correction factors were estimated and applied along the IDDs, showing an improved agreement against MC. Results confirmed that corrections are not negligible for carbon ions, particularly around the BP region.
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Affiliation(s)
- A Mirandola
- Centro Nazionale di Adroterapia Oncologica (CNAO Foundation), I-27100 Pavia, Italy. Author to whom any correspondence should be addressed
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Giordanengo S, Palmans H. Dose detectors, sensors, and their applications. Med Phys 2018; 45:e1051-e1072. [DOI: 10.1002/mp.13089] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Simona Giordanengo
- Istituto Nazionale di Fisica Nucleare, Section of Torino Via Giuria 1 10125 Torino Italy
| | - Hugo Palmans
- National Physical Laboratory Medical Radiation Science Hampton Road Teddington Middlesex TW11 0LW UK
- EBG MedAustron GmbH Marie‐Curiestraße 5 A‐2700 Wiener Neustadt Austria
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Farr JB, Moskvin V, Lukose RC, Tuomanen S, Tsiamas P, Yao W. Development, commissioning, and evaluation of a new intensity modulated minibeam proton therapy system. Med Phys 2018; 45:4227-4237. [PMID: 30009481 DOI: 10.1002/mp.13093] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 07/02/2018] [Accepted: 07/10/2018] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To invent, design, construct, and commission an intensity modulated minibeam proton therapy system (IMMPT) without the need for physical collimation and to compare its resulting conformity to a conventional IMPT system. METHODS A proton therapy system (Hitachi, Ltd, Hitachi City, Japan; Model: Probeat-V) was specially modified to produce scanned minibeams without collimation. We performed integral depth dose acquisitions and calibrations using a large diameter parallel-plate ionization chamber in a scanning water phantom (PTW, Freiburg, Germany; Models: Bragg Peak ionization chamber, MP3-P). Spot size and shape was measured using radiochromic film (Ashland Advanced Materials, Bridgewater NJ; Type: EBT3), and a synthetic diamond diode type scanned point by point in air (PTW Models: MicroDiamond, MP3-P). The measured data were used as inputs to generate a Monte Carlo-based model for a commercial radiotherapy planning system (TPS) (Varian Medical Systems, Inc., Palo Alto, CA; Model: Eclipse v13.7.15). The regular ProBeat-V system (sigma ~2.5 mm) TPS model was available for comparison. A simulated base of skull case with small and medium targets proximal to brainstem was planned for both systems and compared. RESULTS The spot sigma is determined to be 1.4 mm at 221 MeV at the isocenter and below 1 mm at proximal distances. Integral depth doses were indistinguishable from the standard spot commissioning data. The TPS fit the spot profiles closely, giving a residual error maximum of 2.5% in the spot penumbra tails (below 5% of maximum) from the commissioned energies 69.4 to 221.3 MeV. The resulting IMMPT plans were more conformal than the IMPT plans due to a sharper dose gradient (90-10%) 1.5 mm smaller for the small target, and 1.3 mm for the large target, at a representative central axial water equivalent depth of 7 cm. CONCLUSIONS We developed, implemented, and tested a new IMMPT system. The initial results look promising in cases where treatments can benefit from additional dose sparing to neighboring sensitive structures.
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Affiliation(s)
- J B Farr
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - V Moskvin
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - R C Lukose
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - S Tuomanen
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - P Tsiamas
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - W Yao
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
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