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Böhlen TT, Germond JF, Desorgher L, Veres I, Bratel A, Landström E, Engwall E, Herrera FG, Ozsahin EM, Bourhis J, Bochud F, Moeckli R. Very high-energy electron therapy as light-particle alternative to transmission proton FLASH therapy - An evaluation of dosimetric performances. Radiother Oncol 2024; 194:110177. [PMID: 38378075 DOI: 10.1016/j.radonc.2024.110177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/29/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE Clinical translation of FLASH-radiotherapy (RT) to deep-seated tumours is still a technological challenge. One proposed solution consists of using ultra-high dose rate transmission proton (TP) beams of about 200-250 MeV to irradiate the tumour with the flat entrance of the proton depth-dose profile. This work evaluates the dosimetric performance of very high-energy electron (VHEE)-based RT (50-250 MeV) as a potential alternative to TP-based RT for the clinical transfer of the FLASH effect. METHODS Basic physics characteristics of VHEE and TP beams were compared utilizing Monte Carlo simulations in water. A VHEE-enabled research treatment planning system was used to evaluate the plan quality achievable with VHEE beams of different energies, compared to 250 MeV TP beams for a glioblastoma, an oesophagus, and a prostate cancer case. RESULTS Like TP, VHEE above 100 MeV can treat targets with roughly flat (within ± 20 %) depth-dose distributions. The achievable dosimetric target conformity and adjacent organs-at-risk (OAR) sparing is consequently driven for both modalities by their lateral beam penumbrae. Electron beams of 400[500] MeV match the penumbra of 200[250] MeV TP beams and penumbra is increased for lower electron energies. For the investigated patient cases, VHEE plans with energies of 150 MeV and above achieved a dosimetric plan quality comparable to that of 250 MeV TP plans. For the glioblastoma and the oesophagus case, although having a decreased conformity, even 100 MeV VHEE plans provided a similar target coverage and OAR sparing compared to TP. CONCLUSIONS VHEE-based FLASH-RT using sufficiently high beam energies may provide a lighter-particle alternative to TP-based FLASH-RT with comparable dosimetric plan quality.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Laurent Desorgher
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Izabella Veres
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | | | | | | | - Fernanda G Herrera
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Esat Mahmut Ozsahin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland.
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2
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Giannini N, Gadducci G, Fuentes T, Gonnelli A, Di Martino F, Puccini P, Naso M, Pasqualetti F, Capaccioli S, Paiar F. Electron FLASH radiotherapy in vivo studies. A systematic review. Front Oncol 2024; 14:1373453. [PMID: 38655137 PMCID: PMC11035725 DOI: 10.3389/fonc.2024.1373453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/15/2024] [Indexed: 04/26/2024] Open
Abstract
FLASH-radiotherapy delivers a radiation beam a thousand times faster compared to conventional radiotherapy, reducing radiation damage in healthy tissues with an equivalent tumor response. Although not completely understood, this radiobiological phenomenon has been proved in several animal models with a spectrum of all kinds of particles currently used in contemporary radiotherapy, especially electrons. However, all the research teams have performed FLASH preclinical studies using industrial linear accelerator or LINAC commonly employed in conventional radiotherapy and modified for the delivery of ultra-high-dose-rate (UHDRs). Unfortunately, the delivering and measuring of UHDR beams have been proved not to be completely reliable with such devices. Concerns arise regarding the accuracy of beam monitoring and dosimetry systems. Additionally, this LINAC totally lacks an integrated and dedicated Treatment Planning System (TPS) able to evaluate the internal dose distribution in the case of in vivo experiments. Finally, these devices cannot modify dose-time parameters of the beam relevant to the flash effect, such as average dose rate; dose per pulse; and instantaneous dose rate. This aspect also precludes the exploration of the quantitative relationship with biological phenomena. The dependence on these parameters need to be further investigated. A promising advancement is represented by a new generation of electron LINAC that has successfully overcome some of these technological challenges. In this review, we aim to provide a comprehensive summary of the existing literature on in vivo experiments using electron FLASH radiotherapy and explore the promising clinical perspectives associated with this technology.
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Affiliation(s)
- Noemi Giannini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Giovanni Gadducci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Taiusha Fuentes
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Alessandra Gonnelli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Fabio Di Martino
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Unit of Medical Physics, Azienda Ospedaliero-Universitaria Pisana, Pisa, Tuscany, Italy
- National Institute of Nuclear Physics (INFN)-section of Pisa, Pisa, Tuscany, Italy
| | - Paola Puccini
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Monica Naso
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Francesco Pasqualetti
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Simone Capaccioli
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Department of Physics, University of Pisa, Pisa, Tuscany, Italy
| | - Fabiola Paiar
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
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3
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Bateman JJ, Buchanan E, Corsini R, Farabolini W, Korysko P, Garbrecht Larsen R, Malyzhenkov A, Ortega Ruiz I, Rieker V, Gerbershagen A, Dosanjh M. Development of a novel fibre optic beam profile and dose monitor for very high energy electron radiotherapy at ultrahigh dose rates. Phys Med Biol 2024; 69:085006. [PMID: 38478998 DOI: 10.1088/1361-6560/ad33a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
Objective. Very high energy electrons (VHEE) in the range of 50-250 MeV are of interest for treating deep-seated tumours with FLASH radiotherapy (RT). This approach offers favourable dose distributions and the ability to deliver ultra-high dose rates (UHDR) efficiently. To make VHEE-based FLASH treatment clinically viable, a novel beam monitoring technology is explored as an alternative to transmission ionisation monitor chambers, which have non-linear responses at UHDR. This study introduces the fibre optic flash monitor (FOFM), which consists of an array of silica optical fibre-based Cherenkov sensors with a photodetector for signal readout.Approach. Experiments were conducted at the CLEAR facility at CERN using 200 MeV and 160 MeV electrons to assess the FOFM's response linearity to UHDR (characterised with radiochromic films) required for FLASH radiotherapy. Beam profile measurements made on the FOFM were compared to those using radiochromic film and scintillating yttrium aluminium garnet (YAG) screens.Main results. A range of photodetectors were evaluated, with a complementary-metal-oxide-semiconductor (CMOS) camera being the most suitable choice for this monitor. The FOFM demonstrated excellent response linearity from 0.9 Gy/pulse to 57.4 Gy/pulse (R2= 0.999). Furthermore, it did not exhibit any significant dependence on the energy between 160 MeV and 200 MeV nor the instantaneous dose rate. Gaussian fits applied to vertical beam profile measurements indicated that the FOFM could accurately provide pulse-by-pulse beam size measurements, agreeing within the error range of radiochromic film and YAG screen measurements, respectively.Significance. The FOFM proves to be a promising solution for real-time beam profile and dose monitoring for UHDR VHEE beams, with a linear response in the UHDR regime. Additionally it can perform pulse-by-pulse beam size measurements, a feature currently lacking in transmission ionisation monitor chambers, which may become crucial for implementing FLASH radiotherapy and its associated quality assurance requirements.
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Affiliation(s)
- Joseph J Bateman
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
| | - Emma Buchanan
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Roberto Corsini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Wilfrid Farabolini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Pierre Korysko
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Robert Garbrecht Larsen
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander Malyzhenkov
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Iñaki Ortega Ruiz
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Vilde Rieker
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Department of Physics, University of Oslo, NO-0316 Blindern, Oslo, Norway
| | - Alexander Gerbershagen
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Manjit Dosanjh
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
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4
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Deut U, Ronga MG, Bonfrate A, De Marzi L. Secondary radiation dose modeling in passive scattering and pencil beam scanning very high energy electron ( VHEE) radiation therapy. Med Phys 2023. [PMID: 37227704 DOI: 10.1002/mp.16443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND Electrons with kinetic energy up to a few hundred MeV, also called very high energy electrons (VHEE), are currently considered a promising technique for the future of radiation therapy (RT) and in particular ultra-high dose rate (UHDR) therapy. However, the feasibility of a clinical application is still being debated and VHEE therapy remains an active area of research for which the optimal conformal technique is also yet to be determined. PURPOSE In this work, we will apply two existing formalisms based on analytical Gaussian multiple-Coulomb scattering theory and Monte Carlo (MC) simulations to study and compare the electron and bremsstrahlung photon dose distributions arising from two beam delivery systems (passive scattering with or without a collimator or active scanning). METHODS We therefore tested the application of analytical and MC models to VHEE beams and assessed their performance and parameterization in the energy range of 6-200 MeV. The optimized electron beam fluence, the bremsstrahlung, an estimation of central-axis and off-axis x-ray dose at the practical range and neutron contributions to the total dose, along with an extended parameterization for the photon dose model were developed, together with a comparison between double scattering (DS) and pencil beam scanning (PBS) techniques. MC simulations were performed with the TOPAS/Geant4 toolkit to verify the dose distributions predicted by the analytical calculations. RESULTS The results for the clinical energy range (between 6 and 20 MeV) as well as for higher energies (VHEE range between 20 and 200 MeV) and for two treatment field sizes (5 × 5 and 10 × 10 cm2 ) are reported, showing a reasonable agreement with MC simulations with mean differences below 2.1%. The relative contributions of photons generated in the medium or by the scattering system along the central-axis (up to 50% of the total dose) are also illustrated, along with their relative variations with electron energy. CONCLUSIONS The fast analytical models parametrized in this study allow an estimation of the amount of photons produced behind the practical range by a DS system with an accuracy lower than 3%, providing important information for the eventual design of a VHEE system. The results of this work could support future research on VHEE radiotherapy.
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Affiliation(s)
- Umberto Deut
- Radiation Oncology Department, Institut Curie, PSL Research University, Campus universitaire, Orsay, France
| | - Maria Grazia Ronga
- Radiation Oncology Department, Institut Curie, PSL Research University, Campus universitaire, Orsay, France
- Thales Avionics, Vélizy-Villacoublay, France
| | - Anthony Bonfrate
- Radiation Oncology Department, Institut Curie, PSL Research University, Campus universitaire, Orsay, France
| | - Ludovic De Marzi
- Radiation Oncology Department, Institut Curie, PSL Research University, Campus universitaire, Orsay, France
- Institut Curie, PSL Research University, University Paris Saclay, INSERM LITO, Campus universitaire, Orsay, France
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5
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Zhang G, Zhang Z, Gao W, Quan H. Treatment planning consideration for very high-energy electron FLASH radiotherapy. Phys Med 2023; 107:102539. [PMID: 36804694 DOI: 10.1016/j.ejmp.2023.102539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 01/25/2023] [Accepted: 02/01/2023] [Indexed: 02/18/2023] Open
Abstract
PURPOSE Very high-energy electron (VHEE) can make up the insufficient treatment depth of the low-energy electron while offering an intermediate dosimetric advantage between photon and proton. Combining FLASH with VHEE, a quantitative comparison between different energies was made, with regard to plan quality, dose rate distribution (both in PTV and OAR), and total duration of treatment (beam-on time). METHODS In two patient cases (head and lung), we created the treatment plans utilizing the scanning pencil beam via the Monte Carlo simulation and a PTV-based optimization algorithm. Geant4 was used to simulate VHEE pencil beams and sizes of 0.3-5 mm defined by the full width at half maximum (FWHM). Monoenergetic beams with Gaussian distribution in x and y directions (ISOURC = 19) were used as the source of electrons. A large-scale non-linear solver (IPOPT) was used to calculate the optimal spot weights. After optimization, a quantitative comparison between different energies was made regarding treatment plan quality, dose rate distribution (both in PTV and OAR), and total beam duration. RESULTS For head (80 MeV, 100 MeV, and 120 MeV) and lung cases (100 MeV, 120 MeV, and 140 MeV), the minimum beam intensity needs to be ∼2.5 × 1011 electrons/s and ∼9.375 × 1011 electrons/s to allow > 90 % volume of PTV reaching the average dose rate (DADR) higher than 40 Gy/s. At this beam intensity (fraction dose: 10 Gy), the overall irradiation time for the head case is 5258.75 ms (80 MeV), 5149.75 ms (100 MeV), and 4976.75 ms (120 MeV), including scanning time 872.75 ms. For lung cases, this number is 1034.25 ms (100 MeV), 981.55 ms (120 MeV), and 928.15 ms (140 MeV), including scanning time 298.75 ms. The plan of higher energy always performs with a higher dose rate (both in PTV and OAR) and thereby costs less delivery time (beam-on time). CONCLUSION The study systematically investigated the currently known FLASH parameters for VHEE radiotherapy and successfully established a benchmark reference for its FLASH dose rate performance.
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Affiliation(s)
- Guoliang Zhang
- School of Physics and Technology, Wuhan University, 430072, China
| | - Zhengzhao Zhang
- Cancer Radiation Therapy Center, Fifth Medical Center of Chinese PLA General Hospital, 100039, China
| | - Wenchao Gao
- Cancer Radiation Therapy Center, Fifth Medical Center of Chinese PLA General Hospital, 100039, China
| | - Hong Quan
- School of Physics and Technology, Wuhan University, 430072, China.
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6
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Franciosini G, Battistoni G, Cerqua A, De Gregorio A, De Maria P, De Simoni M, Dong Y, Fischetti M, Marafini M, Mirabelli R, Muscato A, Patera V, Salvati F, Sarti A, Sciubba A, Toppi M, Traini G, Trigilio A, Schiavi A. GPU-accelerated Monte Carlo simulation of electron and photon interactions for radiotherapy applications. Phys Med Biol 2023; 68. [PMID: 36356308 DOI: 10.1088/1361-6560/aca1f2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 11/10/2022] [Indexed: 11/12/2022]
Abstract
Objective. The Monte Carlo simulation software is a valuable tool in radiation therapy, in particular to achieve the needed accuracy in the dose evaluation for the treatment plans optimisation. The current challenge in this field is the time reduction to open the way to many clinical applications for which the computational time is an issue. In this manuscript we present an innovative GPU-accelerated Monte Carlo software for dose valuation in electron and photon based radiotherapy, developed as an update of the FRED (Fast paRticle thErapy Dose evaluator) software.Approach. The code transports particles through a 3D voxel grid, while scoring their energy deposition along their trajectory. The models of electromagnetic interactions in the energy region between 1 MeV-1 GeV available in literature have been implemented to efficiently run on GPUs, allowing to combine a fast tracking while keeping high accuracy in dose assessment. The FRED software has been bench-marked against state-of-art full MC (FLUKA, GEANT4) in the realm of two different radiotherapy applications: Intra-Operative Radio Therapy and Very High Electron Energy radiotherapy applications.Results. The single pencil beam dose-depth profiles in water as well as the dose map computed on non-homogeneous phantom agree with full-MCs at 2% level, observing a gain in processing time from 200 to 5000.Significance. Such performance allows for computing a plan with electron beams in few minutes with an accuracy of ∼%, demonstrating the FRED potential to be adopted for fast plan re-calculation in photon or electron radiotherapy applications.
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Affiliation(s)
- G Franciosini
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy
| | - G Battistoni
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Milano, Italy
| | - A Cerqua
- Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - A De Gregorio
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy
| | - P De Maria
- Scuola post-laurea in Fisica Medica, Dipartimento di Scienze e Biotecnologie medico-chirurgiche, Sapienza Universitá di Roma, Roma, Italy
| | - M De Simoni
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy
| | - Y Dong
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Milano, Italy
| | - M Fischetti
- Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - M Marafini
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Museo Storico della Fisica e Centro Studi e Ricerche 'E. Fermi', Roma, Italy
| | - R Mirabelli
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy
| | - A Muscato
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Scuola post-laurea in Fisica Medica, Dipartimento di Scienze e Biotecnologie medico-chirurgiche, Sapienza Universitá di Roma, Roma, Italy
| | - V Patera
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - F Salvati
- Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - A Sarti
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - A Sciubba
- Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy.,Istituto Nazionale di Fisica Nucleare (INFN)- Laboratori Nazionali di Frascati, Frascati, Italy
| | - M Toppi
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
| | - G Traini
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy
| | - A Trigilio
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy
| | - A Schiavi
- Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Roma, Italy.,Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma, Italy
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7
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Rahman M, Trigilio A, Franciosini G, Moeckli R, Zhang R, Böhlen TT. FLASH radiotherapy treatment planning and models for electron beams. Radiother Oncol 2022; 175:210-221. [PMID: 35964763 DOI: 10.1016/j.radonc.2022.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 12/18/2022]
Abstract
The FLASH effect designates normal tissue sparing at ultra-high dose rate (UHDR, >40 Gy/s) compared to conventional dose rate (∼0.1 Gy/s) irradiation while maintaining tumour control and has the potential to improve the therapeutic ratio of radiotherapy (RT). UHDR high-energy electron (HEE, 4-20 MeV) beams are currently a mainstay for investigating the clinical potential of FLASH RT for superficial tumours. In the future very-high energy electron (VHEE, 50-250 MeV) UHDR beams may be used to treat deep-seated tumours. UHDR HEE treatment planning focused at its initial stage on accurate dosimetric modelling of converted and dedicated UHDR electron RT devices for the clinical transfer of FLASH RT. VHEE treatment planning demonstrated promising dosimetric performance compared to clinical photon RT techniques in silico and was used to evaluate and optimise the design of novel VHEE RT devices. Multiple metrics and models have been proposed for a quantitative description of the FLASH effect in treatment planning, but an improved experimental characterization and understanding of the FLASH effect is needed to allow for an accurate and validated modelling of the effect in treatment planning. The importance of treatment planning for electron FLASH RT will augment as the field moves forward to treat more complex clinical indications and target sites. In this review, TPS developments in HEE and VHEE are presented considering beam models, characteristics, and future FLASH applications.
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Affiliation(s)
- Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Antonio Trigilio
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Gaia Franciosini
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland.
| | - Rongxiao Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
| | - Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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8
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De Felice F. FLASH radiotherapy in head and neck cancer: Myth or reality? Oral Oncol 2022; 131:105953. [PMID: 35667292 DOI: 10.1016/j.oraloncology.2022.105953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 05/29/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022]
Affiliation(s)
- Francesca De Felice
- Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Viale Regina Elena 326, 00161 Rome, Italy.
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9
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McManus M, Romano F, Royle G, Palmans H, Subiel A. A Geant4 Fano test for novel very high energy electron beams. Phys Med Biol 2021; 66. [PMID: 34844225 DOI: 10.1088/1361-6560/ac3e0f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 11/29/2021] [Indexed: 11/12/2022]
Abstract
Objective.The boundary crossing algorithm available in Geant4 10.07-p01 general purpose Monte Carlo code has been investigated for a 12 and 200 MeV electron source by the application of a Fano cavity test.Approach.Fano conditions were enforced through all simulations whilst varying individual charged particle transport parameters which control particle step size, ionisation and single scattering.Main Results.At 12 MeV, Geant4 was found to return excellent dose consistency within 0.1% even with the default parameter configurations. The 200 MeV case, however, showed significant consistency issues when default physics parameters were employed with deviations from unity of more than 6%. The effect of the inclusion of nuclear interactions was also investigated for the 200 MeV beam and was found to return good consistency for a number of parameter configurations.Significance.The Fano test is a necessary investigation to ensure the consistency of charged particle transport available in Geant4 before detailed detector simulations can be conducted.
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Affiliation(s)
- M McManus
- National Physicsal Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom.,University College London, Gower Street, WC1E 6BT, United Kingdom
| | - F Romano
- Instituto Nazionale Di Fisica Nucleare, Sezione Di Catania, Catania, Italy
| | - G Royle
- University College London, Gower Street, WC1E 6BT, United Kingdom
| | - H Palmans
- National Physicsal Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom.,MedAustron Ion Therapy Center, Marie-Curie Strasse 5, A-2700 Wiener Neustadt, Austria
| | - A Subiel
- National Physicsal Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
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Böhlen TT, Germond JF, Traneus E, Bourhis J, Vozenin MC, Bailat C, Bochud F, Moeckli R. Characteristics of very high-energy electron beams for the irradiation of deep-seated targets. Med Phys 2021; 48:3958-3967. [PMID: 33884618 DOI: 10.1002/mp.14891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/07/2021] [Accepted: 04/06/2021] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Driven by advances in accelerator technology and the potential of exploiting the FLASH effect for the treatment of deep-seated targets (>5 cm), there is an active interest in the construction of devices to deliver very high-energy electron (VHEE) beams for radiation therapy. The application of novel VHEE devices, however, requires an assessment of the tradeoffs between the different beam parameter choices including beam energies, beam divergences, and maximal field sizes. This study systematically examines the dosimetric beam properties of VHEE beams, determining their clinical usefulness while marking their limits of applications for different beam configurations. METHODS We performed Monte Carlo simulations of the dose distributions of electron beams for different energies (25-250 MeV), source-to-surface distances (SSD) (50 cm, 100 cm, parallel), and field sizes (2 cm2 × 2 cm2 to 15 cm2 × 15 cm2 ) in water using a research version of the RayStation treatment planning system (RaySearch Labs 9A IONPG). The beam was simulated using a monoenergetic point source and perfect collimation. Central axis percentage depth dose (PDD) and transverse dose profiles at multiple depths were evaluated and compared to those of MV photon beams. Profile characteristics including therapeutic range (TR) at 90%, proximal fall-off (PFO) at 90%, lateral penumbra (LP) at 90%-10%, and field width (FW) at 90% were obtained. RESULTS Very high-energy electrons beams with SSD 100 cm and parallel beams (infinite SSD) exhibit a linear to near-linear increase of TR as a function of energy in the simulated energy range and reach values well beyond the typical depths of lesions encountered in clinics (<20 cm). Their TR show a marked field size dependence only for field sizes <10 cm2 × 10 cm2 . For VHEE beams with SSD 50 cm, TR are largely reduced (4-8 cm). For beam energies >150 MeV with large SSD (>100 cm), for many configurations, there is no substantial difference in PDD when adding an opposed beam. This may potentially reduce the number of VHEE beams needed for treatment by a factor of two compared to a treatment using lower energies and lower SSD. In order to cover deep-seated targets homogeneously, VHEE devices with a parallel beam must provide a maximum field size up to several centimeters larger than the tumor size. For the investigated diverging beams, there is not such a significant field width reduction with depth for larger fields as it is compensated by divergence. Penumbrae of VHEE beams are smaller than those of clinical MV photon beams for lower depths (<5 cm) but increase quickly for larger depths. There is only a relatively small dependence of penumbra on the SSD of the beam. CONCLUSIONS The findings presented in this study assess the performance of VHEE beams and offer a first estimate of treatment indications and tradeoffs for a given design of a VHEE device. SSD >100 cm results in clinically more favorable PDD. Beam energies of 100 MeV and above are needed to cover common tumors (5-15 cm in-depth) conformally. Higher energies provide an additional benefit specifically for small and deep-seated lesions due to their reduced lateral penumbrae.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | | | | | - Jean Bourhis
- Radiation-oncology department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Radiation-oncology department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
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