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Moglioni M, Carra P, Arezzini S, Belcari N, Bersani D, Berti A, Bisogni MG, Calderisi M, Ceppa I, Cerello P, Ciocca M, Ferrero V, Fiorina E, Kraan AC, Mazzoni E, Morrocchi M, Pennazio F, Retico A, Rosso V, Sbolgi F, Vitolo V, Sportelli G. Synthetic CT imaging for PET monitoring in proton therapy: a simulation study. Phys Med Biol 2024; 69:065011. [PMID: 38373343 DOI: 10.1088/1361-6560/ad2a99] [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: 09/26/2023] [Accepted: 02/19/2024] [Indexed: 02/21/2024]
Abstract
Objective.This study addresses a fundamental limitation of in-beam positron emission tomography (IB-PET) in proton therapy: the lack of direct anatomical representation in the images it produces. We aim to overcome this shortcoming by pioneering the application of deep learning techniques to create synthetic control CT images (sCT) from combining IB-PET and planning CT scan data.Approach.We conducted simulations involving six patients who underwent irradiation with proton beams. Leveraging the architecture of a visual transformer (ViT) neural network, we developed a model to generate sCT images of these patients using the planning CT scans and the inter-fractional simulated PET activity maps during irradiation. To evaluate the model's performance, a comparison was conducted between the sCT images produced by the ViT model and the authentic control CT images-serving as the benchmark.Main results.The structural similarity index was computed at a mean value across all patients of 0.91, while the mean absolute error measured 22 Hounsfield Units (HU). Root mean squared error and peak signal-to-noise ratio values were 56 HU and 30 dB, respectively. The Dice similarity coefficient exhibited a value of 0.98. These values are comparable to or exceed those found in the literature. More than 70% of the synthetic morphological changes were found to be geometrically compatible with the ones reported in the real control CT scan.Significance.Our study presents an innovative approach to surface the hidden anatomical information of IB-PET in proton therapy. Our ViT-based model successfully generates sCT images from inter-fractional PET data and planning CT scans. Our model's performance stands on par with existing models relying on input from cone beam CT or magnetic resonance imaging, which contain more anatomical information than activity maps.
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Affiliation(s)
- Martina Moglioni
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Pietro Carra
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Silvia Arezzini
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Nicola Belcari
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Davide Bersani
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
| | - Andrea Berti
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Maria Giuseppina Bisogni
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | | | | | - Piergiorgio Cerello
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino, Italy
| | - Mario Ciocca
- Centro Nazionale di Adroterapia Oncologica, I-27100 Pavia, Italy
| | - Veronica Ferrero
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino, Italy
| | - Elisa Fiorina
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino, Italy
| | | | - Enrico Mazzoni
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
| | - Matteo Morrocchi
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | - Francesco Pennazio
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino, Italy
| | - Alessandra Retico
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
| | - Valeria Rosso
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
| | | | - Viviana Vitolo
- Centro Nazionale di Adroterapia Oncologica, I-27100 Pavia, Italy
| | - Giancarlo Sportelli
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy
- Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy
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Botnariuc D, Court S, Lourenço A, Gosling A, Royle G, Hussein M, Rompokos V, Veiga C. Evaluation of monte carlo to support commissioning of the treatment planning system of new pencil beam scanning proton therapy facilities. Phys Med Biol 2024; 69:045027. [PMID: 38052092 DOI: 10.1088/1361-6560/ad1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Objective. To demonstrate the potential of Monte Carlo (MC) to support the resource-intensive measurements that comprise the commissioning of the treatment planning system (TPS) of new proton therapy facilities.Approach. Beam models of a pencil beam scanning system (Varian ProBeam) were developed in GATE (v8.2), Eclipse proton convolution superposition algorithm (v16.1, Varian Medical Systems) and RayStation MC (v12.0.100.0, RaySearch Laboratories), using the beam commissioning data. All models were first benchmarked against the same commissioning data and validated on seven spread-out Bragg peak (SOBP) plans. Then, we explored the use of MC to optimise dose calculation parameters, fully understand the performance and limitations of TPS in homogeneous fields and support the development of patient-specific quality assurance (PSQA) processes. We compared the dose calculations of the TPSs against measurements (DDTPSvs.Meas.) or GATE (DDTPSvs.GATE) for an extensive set of plans of varying complexity. This included homogeneous plans with varying field-size, range, width, and range-shifters (RSs) (n= 46) and PSQA plans for different anatomical sites (n= 11).Main results. The three beam models showed good agreement against the commissioning data, and dose differences of 3.5% and 5% were found for SOBP plans without and with RSs, respectively. DDTPSvs.Meas.and DDTPSvs.GATEwere correlated in most scenarios. In homogeneous fields the Pearson's correlation coefficient was 0.92 and 0.68 for Eclipse and RayStation, respectively. The standard deviation of the differences between GATE and measurements (±0.5% for homogeneous and ±0.8% for PSQA plans) was applied as tolerance when comparing TPSs with GATE. 72% and 60% of the plans were within the GATE predicted dose difference for both TPSs, for homogeneous and PSQA cases, respectively.Significance. Developing and validating a MC beam model early on into the commissioning of new proton therapy facilities can support the validation of the TPS and facilitate comprehensive investigation of its capabilities and limitations.
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Affiliation(s)
- D Botnariuc
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - S Court
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - A Lourenço
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - A Gosling
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - G Royle
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - M Hussein
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - V Rompokos
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - C Veiga
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
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3
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Sheng Y, Volz L, Wang W, Durante M, Graeff C. Evaluation of proton and carbon ion beam models in TReatment Planning for Particles 4D (TRiP4D) referring to a commercial treatment planning system. Z Med Phys 2023:S0939-3889(23)00079-X. [PMID: 37455229 DOI: 10.1016/j.zemedi.2023.06.002] [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: 03/30/2023] [Revised: 05/25/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
PURPOSE To investigate the accuracy of the treatment planning system (TPS) TRiP4D in reproducing doses computed by the clinically used TPS SyngoRT. METHODS Proton and carbon ion beam models in TRiP4D were converted from SyngoRT. Cubic plans with different depths in a water-tank phantom (WP) and previously treated and experimentally verified patient plans from SyngoRT were recalculated in TRiP4D. The target mean dose deviation (ΔDmean,T) and global gamma index (2%-2 mm for the absorbed dose and 3%-3mm for the RBE-weighted dose with 10% threshold) were evaluated. RESULTS The carbon and proton absorbed dose gamma passing rates (γ-PRs) were ≥99.93% and ΔDmean,T smaller than -0.22%. On average, the RBE-weighted dose Dmean,T was -1.26% lower for TRiP4D than SyngoRT for cubic plans. In TRiP4D, the faster analytical 'low dose approximation' (Krämer, 2006) was used, while SyngoRT used a stochastic implementation (Krämer, 2000). The average ΔDmean, T could be reduced to -0.59% when applying the same biological effect calculation algorithm. However, the dose recalculation time increased by a factor of 79-477. ΔDmean,T variation up to -2.27% and -2.79% was observed for carbon absorbed and RBE-weighted doses in patient plans. The γ-PRs were ≥93.92% and ≥91.83% for patient plans, except for one proton beam with a range shifter (γ-PR of 64.19%). CONCLUSION The absorbed dose between TRiP4D and SyngoRT were identical for both proton and carbon ion plans in the WP. Compared to SyngoRT, TRiP4D underestimated the target RBE-weighted dose; however more efficient in RBE-weighted dose calculation. Large variation for proton beam with range shifter was observed. TRiP4D will be used to evaluate doses delivered to moving targets. Uncertainties inherent to the 4D-dose reconstruction calculation are expected to be significantly larger than the dose errors reported here. For this reason, the residual differences between TRiP4D and SyngoRT observed in this study are considered acceptable. The study was approved by the Institutional Research Board of Shanghai Proton and Heavy Ion Center (approval number SPHIC-MP-2020-04, RS).
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Affiliation(s)
- Yinxiangzi Sheng
- Biophysics GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt, Germany; Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China; School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Lennart Volz
- Biophysics GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt, Germany
| | - Weiwei Wang
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China
| | - Marco Durante
- Biophysics GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt, Germany; Institute of Condensed Matter Physics, Technical University of Darmstadt, Darmstadt, Germany
| | - Christian Graeff
- Biophysics GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt, Germany; Institute of Electrical Engineering and Information Technology, Technical University of Darmstadt, Darmstadt, Germany.
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4
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Kraan AC, Berti A, Retico A, Baroni G, Battistoni G, Belcari N, Cerello P, Ciocca M, De Simoni M, Del Sarto D, Donetti M, Dong Y, Embriaco A, Ferrero V, Fiorina E, Fischetti M, Franciosini G, Giraudo G, Laruina F, Maestri D, Magi M, Magro G, Mancini Terracciano C, Marafini M, Mattei I, Mazzoni E, Mereu P, Mirabelli R, Mirandola A, Morrocchi M, Muraro S, Patera A, Patera V, Pennazio F, Rivetti A, Da Rocha Rolo MD, Rosso V, Sarti A, Schiavi A, Sciubba A, Solfaroli Camillocci E, Sportelli G, Tampellini S, Toppi M, Traini G, Valle SM, Valvo F, Vischioni B, Vitolo V, Wheadon R, Bisogni MG. Localization of anatomical changes in patients during proton therapy with in-beam PET monitoring: A voxel-based morphometry approach exploiting Monte Carlo simulations. Med Phys 2021; 49:23-40. [PMID: 34813083 PMCID: PMC9303286 DOI: 10.1002/mp.15336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/30/2021] [Accepted: 10/11/2021] [Indexed: 12/21/2022] Open
Abstract
Purpose In‐beam positron emission tomography (PET) is one of the modalities that can be used for in vivo noninvasive treatment monitoring in proton therapy. Although PET monitoring has been frequently applied for this purpose, there is still no straightforward method to translate the information obtained from the PET images into easy‐to‐interpret information for clinical personnel. The purpose of this work is to propose a statistical method for analyzing in‐beam PET monitoring images that can be used to locate, quantify, and visualize regions with possible morphological changes occurring over the course of treatment. Methods We selected a patient treated for squamous cell carcinoma (SCC) with proton therapy, to perform multiple Monte Carlo (MC) simulations of the expected PET signal at the start of treatment, and to study how the PET signal may change along the treatment course due to morphological changes. We performed voxel‐wise two‐tailed statistical tests of the simulated PET images, resembling the voxel‐based morphometry (VBM) method commonly used in neuroimaging data analysis, to locate regions with significant morphological changes and to quantify the change. Results The VBM resembling method has been successfully applied to the simulated in‐beam PET images, despite the fact that such images suffer from image artifacts and limited statistics. Three dimensional probability maps were obtained, that allowed to identify interfractional morphological changes and to visualize them superimposed on the computed tomography (CT) scan. In particular, the characteristic color patterns resulting from the two‐tailed statistical tests lend themselves to trigger alarms in case of morphological changes along the course of treatment. Conclusions The statistical method presented in this work is a promising method to apply to PET monitoring data to reveal interfractional morphological changes in patients, occurring over the course of treatment. Based on simulated in‐beam PET treatment monitoring images, we showed that with our method it was possible to correctly identify the regions that changed. Moreover we could quantify the changes, and visualize them superimposed on the CT scan. The proposed method can possibly help clinical personnel in the replanning procedure in adaptive proton therapy treatments.
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Affiliation(s)
| | - Andrea Berti
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | | | - Guido Baroni
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy.,Politecnico di Milano, Milano, Italy
| | | | - Nicola Belcari
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | | | - Mario Ciocca
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Micol De Simoni
- Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy
| | - Damiano Del Sarto
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | - Marco Donetti
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Yunsheng Dong
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy.,Dipartimento di Fisica, Università di Milano, Milano, Italy
| | - Alessia Embriaco
- Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Pavia, Italy
| | - Veronica Ferrero
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Elisa Fiorina
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Marta Fischetti
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - Gaia Franciosini
- Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy
| | - Giuseppe Giraudo
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Francesco Laruina
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | - Davide Maestri
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Marco Magi
- Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - Giuseppe Magro
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Carlo Mancini Terracciano
- Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy
| | - Michela Marafini
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy
| | - Ilaria Mattei
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy
| | - Enrico Mazzoni
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy
| | - Paolo Mereu
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Riccardo Mirabelli
- Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy
| | | | - Matteo Morrocchi
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | - Silvia Muraro
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy
| | - Alessandra Patera
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Vincenzo Patera
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy
| | | | - Angelo Rivetti
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | | | - Valeria Rosso
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | - Alessio Sarti
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy
| | - Angelo Schiavi
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - Adalberto Sciubba
- Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione dei Laboratori di Frascati, Frascati, RM, Italy
| | - Elena Solfaroli Camillocci
- Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy
| | - Giancarlo Sportelli
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
| | | | - Marco Toppi
- Dipartimento di Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione dei Laboratori di Frascati, Frascati, RM, Italy
| | - Giacomo Traini
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Roma, Italy
| | | | | | | | - Viviana Vitolo
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Richard Wheadon
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy
| | - Maria Giuseppina Bisogni
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy.,Dipartimento di Fisica, Università di Pisa, Pisa, Italy
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Elia A, Resch AF, Carlino A, Böhlen TT, Fuchs H, Palmans H, Letellier V, Dreindl R, Osorio J, Stock M, Sarrut D, Grevillot L. A GATE/Geant4 beam model for the MedAustron non-isocentric proton treatment plans quality assurance. Phys Med 2020; 71:115-123. [DOI: 10.1016/j.ejmp.2020.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/23/2019] [Accepted: 02/07/2020] [Indexed: 10/24/2022] Open
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Molinelli S, Russo S, Magro G, Maestri D, Mairani A, Mastella E, Mirandola A, Vai A, Vischioni B, Valvo F, Ciocca M. Impact of TPS calculation algorithms on dose delivered to the patient in proton therapy treatments. ACTA ACUST UNITED AC 2019; 64:075016. [DOI: 10.1088/1361-6560/ab0a4d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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7
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Ciocca M, Magro G, Mastella E, Mairani A, Mirandola A, Molinelli S, Russo S, Vai A, Fiore MR, Mosci C, Valvo F, Via R, Baroni G, Orecchia R. Design and commissioning of the non-dedicated scanning proton beamline for ocular treatment at the synchrotron-based CNAO facility. Med Phys 2019; 46:1852-1862. [PMID: 30659616 DOI: 10.1002/mp.13389] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 12/11/2018] [Accepted: 01/09/2019] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Only few centers worldwide treat intraocular tumors with proton therapy, all of them with a dedicated beamline, except in one case in the USA. The Italian National Center for Oncological Hadrontherapy (CNAO) is a synchrotron-based hadrontherapy facility equipped with fixed beamlines and pencil beam scanning modality. Recently, a general-purpose horizontal proton beamline was adapted to treat also ocular diseases. In this work, the conceptual design and main dosimetric properties of this new proton eyeline are presented. METHODS A 28 mm thick water-equivalent range shifter (RS) was placed along the proton beamline to shift the minimum beam penetration at shallower depths. FLUKA Monte Carlo (MC) simulations were performed to optimize the position of the RS and patient-specific collimator, in order to achieve sharp lateral dose gradients. Lateral dose profiles were then measured with radiochromic EBT3 films to evaluate the dose uniformity and lateral penumbra width at several depths. Different beam scanning patterns were tested. Discrete energy levels with 1 mm water-equivalent step within the whole ocular energy range (62.7-89.8 MeV) were used, while fine adjustment of beam range was achieved using thin polymethylmethacrylate additional sheets. Depth-dose distributions (DDDs) were measured with the Peakfinder system. Monoenergetic beam weights to achieve flat spread-out Bragg Peaks (SOBPs) were numerically determined. Absorbed dose to water under reference conditions was measured with an Advanced Markus chamber, following International Atomic Energy Agency (IAEA) Technical Report Series (TRS)-398 Code of Practice. Neutron dose at the contralateral eye was evaluated with passive bubble dosimeters. RESULTS Monte Carlo simulations and experimental results confirmed that maximizing the air gap between RS and aperture reduces the lateral dose penumbra width of the collimated beam and increases the field transversal dose homogeneity. Therefore, RS and brass collimator were placed at about 98 cm (upstream of the beam monitors) and 7 cm from the isocenter, respectively. The lateral 80%-20% penumbra at middle-SOBP ranged between 1.4 and 1.7 mm depending on field size, while 90%-10% distal fall-off of the DDDs ranged between 1.0 and 1.5 mm, as a function of range. Such values are comparable to those reported for most existing eye-dedicated facilities. Measured SOBP doses were in very good agreement with MC simulations. Mean neutron dose at the contralateral eye was 68 μSv/Gy. Beam delivery time, for 60 Gy relative biological effectiveness (RBE) prescription dose in four fractions, was around 3 min per session. CONCLUSIONS Our adapted scanning proton beamline satisfied the requirements for intraocular tumor treatment. The first ocular treatment was delivered in August 2016 and more than 100 patients successfully completed their treatment in these 2 yr.
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Affiliation(s)
- Mario Ciocca
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy
| | - Giuseppe Magro
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy
| | | | - Andrea Mairani
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy
| | | | | | - Stefania Russo
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy
| | - Alessandro Vai
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy
| | | | - Carlo Mosci
- Ente Ospedaliero Ospedali Galliera, via Mura delle Cappuccine 14, 16128, Genova, Italy
| | | | - Riccardo Via
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Guido Baroni
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy.,Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Roberto Orecchia
- Fondazione CNAO, strada Campeggi 53, 27100, Pavia, Italy.,Istituto Europeo di Oncologia, via Ripamonti 435, 20100, Milano, Italy
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DePew KD, Ahmad S, Jin H. Experimental Assessment of Proton Dose Calculation Accuracy in Small-Field Delivery Using a Mevion S250 Proton Therapy System. J Med Phys 2019; 43:221-229. [PMID: 30636847 PMCID: PMC6299753 DOI: 10.4103/jmp.jmp_33_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Purpose: Dose calculation accuracy of the Varian Eclipse treatment planning system (TPS) is empirically assessed for small-aperture fields using a Mevion S250 double scattering proton therapy system. Materials and Methods: Five spherical pseudotumors were modeled in a RANDO head phantom. Plans were generated for the targets with apertures of 1, 2, 3, 4, or 5 cm diameter using one, two, and three beams. Depth-dose curves and lateral profiles of the beams were taken with the planned blocks and compared to Eclipse calculations. Dose distributions measured with EBT3 films in the phantom were also compared to Eclipse calculations. Film quenching effect was simulated and considered. Results: Depth-dose scans in water showed a range pullback (up to 2.0 mm), modulation widening (up to 9.5 mm), and dose escalation in proximal end and sub-peak region (up to 15.5%) when compared to the Eclipse calculations for small fields. Measured full width at half maximum and penumbrae for lateral profiles differed <1.0 mm from calculations for most comparisons. In the phantom study, Eclipse TPS underestimated sub-peak dose. Gamma passing rates improved with each beam added to the plans. Greater range pullback and modulation degradation versus water scans were observed due to film quenching, which became more noticeable as target size increased. Conclusions: Eclipse TPS generates acceptable target coverage for small targets with carefully arranged multiple beams despite relatively large dose discrepancy for each beam. Surface doses higher than Eclipse calculations can be mitigated with multiple beams. When using EBT3 film, the quenching effect should be considered.
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Affiliation(s)
- Kyle D DePew
- Department of Radiation Oncology, University of Oklahoma Health Sciences Centre, Oklahoma City, Oklahoma, USA
| | - Salahuddin Ahmad
- Department of Radiation Oncology, University of Oklahoma Health Sciences Centre, Oklahoma City, Oklahoma, USA
| | - Hosang Jin
- Department of Radiation Oncology, University of Oklahoma Health Sciences Centre, Oklahoma City, Oklahoma, USA
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FRoG-A New Calculation Engine for Clinical Investigations with Proton and Carbon Ion Beams at CNAO. Cancers (Basel) 2018; 10:cancers10110395. [PMID: 30360576 PMCID: PMC6266031 DOI: 10.3390/cancers10110395] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 11/17/2022] Open
Abstract
A fast and accurate dose calculation engine for hadrontherapy is critical for both routine clinical and advanced research applications. FRoG is a graphics processing unit (GPU)-based forward calculation tool developed at CNAO (Centro Nazionale di Adroterapia Oncologica) and at HIT (Heidelberg Ion Beam Therapy Center) for fast and accurate calculation of both physical and biological dose. FRoG calculation engine adopts a triple Gaussian parameterization for the description of the lateral dose distribution. FRoG provides dose, dose-averaged linear energy transfer, and biological dose-maps, -profiles, and -volume-histograms. For the benchmark of the FRoG calculation engine, using the clinical settings available at CNAO, spread-out Bragg peaks (SOBPs) and patient cases for both proton and carbon ion beams have been calculated and compared against FLUKA Monte Carlo (MC) predictions. In addition, FRoG patient-specific quality assurance (QA) has been performed for twenty-five proton and carbon ion fields. As a result, for protons, biological dose values, using a relative biological effectiveness (RBE) of 1.1, agree on average with MC within ~1% for both SOBPs and patient plans. For carbon ions, RBE-weighted dose (DRBE) agreement against FLUKA is within ~2.5% for the studied SOBPs and patient plans. Both MKM (Microdosimetric Kinetic Model) and LEM (Local Effect Model) DRBE are implemented and tested in FRoG to support the NIRS (National Institute of Radiological Sciences)-based to LEM-based biological dose conversion. FRoG matched the measured QA dosimetric data within ~2.0% for both particle species. The typical calculation times for patients ranged from roughly 1 to 4 min for proton beams and 3 to 6 min for carbon ions on a NVIDIA® GeForce® GTX 1080 Ti. This works demonstrates FRoG's potential to bolster clinical activity with proton and carbon ion beams at CNAO.
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Fast robust dose calculation on GPU for high-precision 1H, 4He, 12C and 16O ion therapy: the FRoG platform. Sci Rep 2018; 8:14829. [PMID: 30287930 PMCID: PMC6172246 DOI: 10.1038/s41598-018-33194-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022] Open
Abstract
Radiotherapy with protons and heavier ions landmarks a novel era in the field of high-precision cancer therapy. To identify patients most benefiting from this technologically demanding therapy, fast assessment of comparative treatment plans utilizing different ion species is urgently needed. Moreover, to overcome uncertainties of actual in-vivo physical dose distribution and biological effects elicited by different radiation qualities, development of a reliable high-throughput algorithm is required. To this end, we engineered a unique graphics processing unit (GPU) based software architecture allowing rapid and robust dose calculation. FRoG, Fast Recalculation on GPU, currently operates with four particle beams available at Heidelberg Ion Beam Therapy center, i.e., raster-scanning proton (1H), helium (4He), carbon (12C) and oxygen ions (16O). FRoG enables comparative analysis of different models for estimation of physical and biological effective dose in 3D within minutes and in excellent agreement with the gold standard Monte Carlo (MC) simulation. This is a crucial step towards development of next-generation patient specific radiotherapy.
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Fiorini F, Schreuder N, Van den Heuvel F. Technical Note: Defining cyclotron-based clinical scanning proton machines in a FLUKA Monte Carlo system. Med Phys 2018; 45:963-970. [PMID: 29178429 PMCID: PMC6571526 DOI: 10.1002/mp.12701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/09/2017] [Accepted: 11/20/2017] [Indexed: 01/13/2023] Open
Abstract
PURPOSE Cyclotron-based pencil beam scanning (PBS) proton machines represent nowadays the majority and most affordable choice for proton therapy facilities, however, their representation in Monte Carlo (MC) codes is more complex than passively scattered proton system- or synchrotron-based PBS machines. This is because degraders are used to decrease the energy from the cyclotron maximum energy to the desired energy, resulting in a unique spot size, divergence, and energy spread depending on the amount of degradation. This manuscript outlines a generalized methodology to characterize a cyclotron-based PBS machine in a general-purpose MC code. The code can then be used to generate clinically relevant plans starting from commercial TPS plans. METHODS The described beam is produced at the Provision Proton Therapy Center (Knoxville, TN, USA) using a cyclotron-based IBA Proteus Plus equipment. We characterized the Provision beam in the MC FLUKA using the experimental commissioning data. The code was then validated using experimental data in water phantoms for single pencil beams and larger irregular fields. Comparisons with RayStation TPS plans are also presented. RESULTS Comparisons of experimental, simulated, and planned dose depositions in water plans show that same doses are calculated by both programs inside the target areas, while penumbrae differences are found at the field edges. These differences are lower for the MC, with a γ(3%-3 mm) index never below 95%. CONCLUSIONS Extensive explanations on how MC codes can be adapted to simulate cyclotron-based scanning proton machines are given with the aim of using the MC as a TPS verification tool to check and improve clinical plans. For all the tested cases, we showed that dose differences with experimental data are lower for the MC than TPS, implying that the created FLUKA beam model is better able to describe the experimental beam.
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Affiliation(s)
- Francesca Fiorini
- CRUK – MRC Oxford Institute for Radiation Oncology University of OxfordOxfordUK
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Tessonnier T, Mairani A, Chen W, Sala P, Cerutti F, Ferrari A, Haberer T, Debus J, Parodi K. Proton and helium ion radiotherapy for meningioma tumors: a Monte Carlo-based treatment planning comparison. Radiat Oncol 2018; 13:2. [PMID: 29316969 PMCID: PMC5759862 DOI: 10.1186/s13014-017-0944-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/14/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Due to their favorable physical and biological properties, helium ion beams are increasingly considered a promising alternative to proton beams for radiation therapy. Hence, this work aims at comparing in-silico the treatment of brain and ocular meningiomas with protons and helium ions, using for the first time a dedicated Monte Carlo (MC) based treatment planning engine (MCTP) thoroughly validated both in terms of physical and biological models. METHODS Starting from clinical treatment plans of four patients undergoing proton therapy with a fixed relative biological effectiveness (RBE) of 1.1 and a fraction dose of 1.8 Gy(RBE), new treatment plans were optimized with MCTP for both protons (with variable and fixed RBE) and helium ions (with variable RBE) under the same constraints derived from the initial clinical plans. The resulting dose distributions were dosimetrically compared in terms of dose volume histograms (DVH) parameters for the planning target volume (PTV) and the organs at risk (OARs), as well as dose difference maps. RESULTS In most of the cases helium ion plans provided a similar PTV coverage as protons with a consistent trend of superior OAR sparing. The latter finding was attributed to the ability of helium ions to offer sharper distal and lateral dose fall-offs, as well as a more favorable differential RBE variation in target and normal tissue. CONCLUSIONS Although more studies are needed to investigate the clinical potential of helium ions for different tumour entities, the results of this work based on an experimentally validated MC engine support the promise of this modality with state-of-the-art pencil beam scanning delivery, especially in case of tumours growing in close proximity of multiple OARs such as meningiomas.
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Affiliation(s)
- Thomas Tessonnier
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Andrea Mairani
- Heidelberg Ion Beam Therapy Center, Heidelberg, Germany
- Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Wenjing Chen
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - Paola Sala
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milan, Italy
- European Organization for Nuclear Research, CERN, Geneva, Switzerland
| | - Francesco Cerutti
- European Organization for Nuclear Research, CERN, Geneva, Switzerland
| | - Alfredo Ferrari
- European Organization for Nuclear Research, CERN, Geneva, Switzerland
| | | | - Jürgen Debus
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center, Heidelberg, Germany
| | - Katia Parodi
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Munich, Germany
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Shirey RJ, Wu HT. Quantifying the effect of air gap, depth, and range shifter thickness on TPS dosimetric accuracy in superficial PBS proton therapy. J Appl Clin Med Phys 2017; 19:164-173. [PMID: 29239528 PMCID: PMC5768007 DOI: 10.1002/acm2.12241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/04/2017] [Accepted: 10/30/2017] [Indexed: 11/23/2022] Open
Abstract
This study quantifies the dosimetric accuracy of a commercial treatment planning system as functions of treatment depth, air gap, and range shifter thickness for superficial pencil beam scanning proton therapy treatments. The RayStation 6 pencil beam and Monte Carlo dose engines were each used to calculate the dose distributions for a single treatment plan with varying range shifter air gaps. Central axis dose values extracted from each of the calculated plans were compared to dose values measured with a calibrated PTW Markus chamber at various depths in RW3 solid water. Dose was measured at 12 depths, ranging from the surface to 5 cm, for each of the 18 different air gaps, which ranged from 0.5 to 28 cm. TPS dosimetric accuracy, defined as the ratio of calculated dose relative to the measured dose, was plotted as functions of depth and air gap for the pencil beam and Monte Carlo dose algorithms. The accuracy of the TPS pencil beam dose algorithm was found to be clinically unacceptable at depths shallower than 3 cm with air gaps wider than 10 cm, and increased range shifter thickness only added to the dosimetric inaccuracy of the pencil beam algorithm. Each configuration calculated with Monte Carlo was determined to be clinically acceptable. Further comparisons of the Monte Carlo dose algorithm to the measured spread‐out Bragg Peaks of multiple fields used during machine commissioning verified the dosimetric accuracy of Monte Carlo in a variety of beam energies and field sizes. Discrepancies between measured and TPS calculated dose values can mainly be attributed to the ability (or lack thereof) of the TPS pencil beam dose algorithm to properly model secondary proton scatter generated in the range shifter.
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Affiliation(s)
- Robert J Shirey
- Radiation Oncology, Aurora BayCare Medical Center, Green Bay, WI, USA
| | - Hsinshun Terry Wu
- Radiation Oncology, Willis-Knighton Cancer Center, Shreveport, LA, USA
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Giordanengo S, Manganaro L, Vignati A. Review of technologies and procedures of clinical dosimetry for scanned ion beam radiotherapy. Phys Med 2017; 43:79-99. [DOI: 10.1016/j.ejmp.2017.10.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 09/23/2017] [Accepted: 10/18/2017] [Indexed: 12/17/2022] Open
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Schiavi A, Senzacqua M, Pioli S, Mairani A, Magro G, Molinelli S, Ciocca M, Battistoni G, Patera V. Fred: a GPU-accelerated fast-Monte Carlo code for rapid treatment plan recalculation in ion beam therapy. ACTA ACUST UNITED AC 2017; 62:7482-7504. [DOI: 10.1088/1361-6560/aa8134] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Tessonnier T, Böhlen TT, Ceruti F, Ferrari A, Sala P, Brons S, Haberer T, Debus J, Parodi K, Mairani A. Dosimetric verification in water of a Monte Carlo treatment planning tool for proton, helium, carbon and oxygen ion beams at the Heidelberg Ion Beam Therapy Center. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1361-6560/aa7be4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Trnková P, Bolsi A, Albertini F, Weber DC, Lomax AJ. Factors influencing the performance of patient specific quality assurance for pencil beam scanning IMPT fields. Med Phys 2017; 43:5998. [PMID: 27806620 DOI: 10.1118/1.4964449] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE A detailed analysis of 2728 intensity modulated proton therapy (IMPT) fields that were clinically delivered to patients between 2007 and 2013 at Paul Scherrer Institute (PSI) was performed. The aim of this study was to analyze the results of patient specific dosimetric verifications and to assess possible correlation between the quality assurance (QA) results and specific field metrics. METHODS Dosimetric verifications were performed for every IMPT field prior to patient treatment. For every field, a steering file was generated containing all the treatment unit information necessary for treatment delivery: beam energy, beam angle, dose, size of air gap, nuclear interaction (NI) correction factor, number of range shifter plates, number of Bragg peaks (BPs) with their position and weight. This information was extracted and correlated to the results of dosimetric verification of each field which was a measurement of two orthogonal profiles using an orthogonal ionization chamber array in a movable water column. RESULTS The data analysis has shown more than 94% of all verified plans were within defined clinical tolerances. The differences between measured and calculated dose depend critically on the number of BPs, total thickness of all range shifter plates inserted in the beam path, and maximal range. An increase of the dose difference was observed with smaller number of BPs (i.e., smaller tumor) and smaller ranges (i.e., superficial tumors). The results of the verification do not depend, however, on the prescribed dose, NI correction, or the size of the air gap. There is no dependency of the transversal and longitudinal spot position precision on the beam angle. The value of NI correction depends on the number of spots and number of range shifter plates. CONCLUSIONS The presented study has shown that the verification method used at Centre for Proton Therapy at Paul Scherrer Institute is accurate and reproducible for performing patient specific QA. The results confirmed that the dose discrepancy is dependent on the size and location of the tumor.
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Affiliation(s)
- P Trnková
- Centre for Proton Therapy, Paul Scherrer Institute, PSI West, Villigen 5232, Switzerland
| | - A Bolsi
- Centre for Proton Therapy, Paul Scherrer Institute, PSI West, Villigen 5232, Switzerland
| | - F Albertini
- Centre for Proton Therapy, Paul Scherrer Institute, PSI West, Villigen 5232, Switzerland
| | - D C Weber
- Centre for Proton Therapy, Paul Scherrer Institute, PSI West, Villigen 5232, Switzerland and Radiation Oncology Department, University of Zürich, Rämistrasse 71, Zürich 8006, Switzerland
| | - A J Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, PSI West, Villigen 5232, Switzerland and Department of Physics, ETH Zürich, Rämistrasse 101, Zürich 8092, Switzerland
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Tessonnier T, Marcelos T, Mairani A, Brons S, Parodi K. Phase Space Generation for Proton and Carbon Ion Beams for External Users' Applications at the Heidelberg Ion Therapy Center. Front Oncol 2016; 5:297. [PMID: 26793617 PMCID: PMC4707204 DOI: 10.3389/fonc.2015.00297] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/14/2015] [Indexed: 12/04/2022] Open
Abstract
In the field of radiation therapy, accurate and robust dose calculation is required. For this purpose, precise modeling of the irradiation system and reliable computational platforms are needed. At the Heidelberg Ion Therapy Center (HIT), the beamline has been already modeled in the FLUKA Monte Carlo (MC) code. However, this model was kept confidential for disclosure reasons and was not available for any external team. The main goal of this study was to create efficiently phase space (PS) files for proton and carbon ion beams, for all energies and foci available at HIT. PSs are representing the characteristics of each particle recorded (charge, mass, energy, coordinates, direction cosines, generation) at a certain position along the beam path. In order to achieve this goal, keeping a reasonable data size but maintaining the requested accuracy for the calculation, we developed a new approach of beam PS generation with the MC code FLUKA. The generated PSs were obtained using an infinitely narrow beam and recording the desired quantities after the last element of the beamline, with a discrimination of primaries or secondaries. In this way, a unique PS can be used for each energy to accommodate the different foci by combining the narrow-beam scenario with a random sampling of its theoretical Gaussian beam in vacuum. PS can also reproduce the different patterns from the delivery system, when properly combined with the beam scanning information. MC simulations using PS have been compared to simulations, including the full beamline geometry and have been found in very good agreement for several cases (depth dose distributions, lateral dose profiles), with relative dose differences below 0.5%. This approach has also been compared with measured data of ion beams with different energies and foci, resulting in a very satisfactory agreement. Hence, the proposed approach was able to fulfill the different requirements and has demonstrated its capability for application to clinical treatment fields. It also offers a powerful tool to perform investigations on the contribution of primary and secondary particles produced in the beamline. These PSs are already made available to external teams upon request, to support interpretation of their measurements.
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Affiliation(s)
- Thomas Tessonnier
- Department of Radiation Oncology, Heidelberg University Clinic, Heidelberg, Germany; Department of Medical Physics, Ludwig Maximilians University, Munich, Germany
| | - Tiago Marcelos
- Department of Medical Physics, Ludwig Maximilians University , Munich , Germany
| | - Andrea Mairani
- Heidelberg Ion Beam Therapy Center, Heidelberg, Germany; Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Stephan Brons
- Heidelberg Ion Beam Therapy Center , Heidelberg , Germany
| | - Katia Parodi
- Department of Medical Physics, Ludwig Maximilians University, Munich, Germany; Heidelberg Ion Beam Therapy Center, Heidelberg, Germany
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Würl M, Englbrecht F, Parodi K, Hillbrand M. Dosimetric impact of the low-dose envelope of scanned proton beams at a ProBeam facility: comparison of measurements with TPS and MC calculations. Phys Med Biol 2016; 61:958-73. [DOI: 10.1088/0031-9155/61/2/958] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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