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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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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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Jeon C, Lee J, Shin J, Cheon W, Ahn S, Jo K, Han Y. Monte Carlo simulation-based patient-specific QA using machine log files for line-scanning proton radiation therapy. Med Phys 2023; 50:7139-7153. [PMID: 37756652 DOI: 10.1002/mp.16747] [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: 10/31/2022] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Quality assurance (QA) is a prerequisite for safe and accurate pencil-beam proton therapy. Conventional measurement-based patient-specific QA (pQA) can only verify limited aspects of patient treatment and is labor-intensive. Thus, a better method is needed to ensure the integrity of the treatment plan. PURPOSE Line scanning, which involves continuous and rapid delivery of pencil beams, is a state-of-the-art proton therapy technique. Machine performance in delivering scanning protons is dependent on the complexity of the beam modulations. Moreover, it contributes to patient treatment accuracy. A Monte Carlo (MC) simulation-based QA method that reflects the uncertainty related to the machine during scanning beam delivery was developed and verified for clinical applications to pQA. METHODS Herein, a tool for particle simulation (TOPAS) for nozzle modeling was used, and the code was commissioned against the measurements. To acquire the beam delivery uncertainty for each plan, patient plans were delivered. Furthermore, log files recorded every 60 μs by the monitors downstream of the nozzle were exported from the treatment control system. The spot positions and monitor unit (MU) counts in the log files were converted to dipole magnet strengths and number of particles, respectively, and entered into the TOPAS. For the 68 clinical cases, MC simulations were performed in a solid water phantom, and two-dimensional (2D) absolute dose distributions at 20-mm depth were measured using an ionization chamber array (Octavius 1500, PTW, Freiburg, Germany). Consequently, the MC-simulated 2D dose distributions were compared with the measured data, and the dose distributions in the pre-treatment QA plan created with RayStation (RaySearch Laboratories, Stockholm, Sweden). Absolute dose comparisons were made using gamma analysis with 3%/3 mm and 2%/2 mm criteria for 47 clinical cases without considering daily machine output variation in the MC simulation and 21 cases with daily output variation, respectively. All cases were analyzed with 90% or 95% of passing rate thresholds. RESULTS For 47 clinical cases not considering daily output variations, the absolute gamma passing rates compared with the pre-treatment QA plan were 99.71% and 96.97%, and the standard deviations (SD) were 0.70% and 3.78% with the 3%/3 mm or 2%/2 mm criteria, respectively. Compared with the measurements, the passing rate of 2%/2 mm gamma criterion was 96.76% with 3.99% of SD. For the 21 clinical cases compared with pre-treatment QA plan data and measurements considering daily output variations, the 2%/2 mm absolute gamma analysis result was 98.52% with 1.43% of SD and 97.67% with 2.72% of SD, respectively. With a 95% passing rate threshold of 2%/2 mm criterion, the false-positive and false-negative were 21.8% and 8.3% for without and with considering output variation, respectively. With a 90% threshold, the false-positive and false-negative reduced to 11.4% and 0% for without and with considering output variation, respectively. CONCLUSIONS A log-file-based MC simulation method for patient QA of line-scanning proton therapy was successfully developed. The proposed method exhibited clinically acceptable accuracy, thereby exhibiting a potential to replace the measurement-based dosimetry QA method with a 90% gamma passing rate threshold when applying the 2%/2 mm criterion.
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Affiliation(s)
- Chanil Jeon
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jinhyeop Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jungwook Shin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Rockville, Maryland, USA
| | - Wonjoong Cheon
- Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sunghwan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea
| | - Kwanghyun Jo
- Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea
| | - Youngyih Han
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea
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Duetschler A, Winterhalter C, Meier G, Safai S, Weber DC, Lomax AJ, Zhang Y. A fast analytical dose calculation approach for MRI-guided proton therapy. Phys Med Biol 2023; 68:195020. [PMID: 37750045 DOI: 10.1088/1361-6560/acf90d] [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: 05/08/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023]
Abstract
Objective.Magnetic resonance (MR) is an innovative technology for online image guidance in conventional radiotherapy and is also starting to be considered for proton therapy as well. For MR-guided therapy, particularly for online plan adaptations, fast dose calculation is essential. Monte Carlo (MC) simulations, however, which are considered the gold standard for proton dose calculations, are very time-consuming. To address the need for an efficient dose calculation approach for MRI-guided proton therapy, we have developed a fast GPU-based modification of an analytical dose calculation algorithm incorporating beam deflections caused by magnetic fields.Approach.Proton beams (70-229 MeV) in orthogonal magnetic fields (0.5/1.5 T) were simulated using TOPAS-MC and central beam trajectories were extracted to generate look-up tables (LUTs) of incremental rotation angles as a function of water-equivalent depth. Beam trajectories are then reconstructed using these LUTs for the modified ray casting dose calculation. The algorithm was validated against MC in water, different materials and for four example patient cases, whereby it has also been fully incorporated into a treatment plan optimisation regime.Main results.Excellent agreement between analytical and MC dose distributions could be observed with sub-millimetre range deviations and differences in lateral shifts <2 mm even for high densities (1000 HU). 2%/2 mm gamma pass rates were comparable to the 0 T scenario and above 94.5% apart for the lung case. Further, comparable treatment plan quality could be achieved regardless of magnetic field strength.Significance.A new method for accurate and fast proton dose calculation in magnetic fields has been developed and successfully implemented for treatment plan optimisation.
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Affiliation(s)
- Alisha Duetschler
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, CH, Switzerland
| | - Carla Winterhalter
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
| | - Gabriel Meier
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, 8091 Zürich, CH, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, CH, Switzerland
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, CH, Switzerland
| | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
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Togno M, Nesteruk KP, Schäfer R, Psoroulas S, Meer D, Grossmann M, Christensen JB, Yukihara EG, Lomax AJ, Weber DC, Safai S. Ultra-high dose rate dosimetry for pre-clinical experiments with mm-small proton fields. Phys Med 2022; 104:101-111. [PMID: 36395638 DOI: 10.1016/j.ejmp.2022.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 10/10/2022] [Accepted: 10/23/2022] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To characterize an experimental setup for ultra-high dose rate (UHDR) proton irradiations, and to address the challenges of dosimetry in millimetre-small pencil proton beams. METHODS At the PSI Gantry 1, high-energy transmission pencil beams can be delivered to biological samples and detectors up to a maximum local dose rate of ∼9000 Gy/s. In the presented setup, a Faraday cup is used to measure the delivered number of protons up to ultra-high dose rates. The response of transmission ion-chambers, as well as of different field detectors, was characterized over a wide range of dose rates using the Faraday cup as reference. RESULTS The reproducibility of the delivered proton charge was better than 1 % in the proposed experimental setup. EBT3 films, Al2O3:C optically stimulated luminescence detectors and a PTW microDiamond were used to validate the predicted dose. Transmission ionization chambers showed significant volume ion-recombination (>30 % in the tested conditions) which can be parametrized as a function of the maximum proton current density. Over the considered range, EBT3 films, inorganic scintillator-based screens and the PTW microDiamond were demonstrated to be dose rate independent within ±3 %, ±1.8 % and ±1 %, respectively. CONCLUSIONS Faraday cups are versatile dosimetry instruments that can be used for dose estimation, field detector characterization and on-line dose verification for pre-clinical experiments in UHDR proton pencil beams. Among the tested detectors, the commercial PTW microDiamond was found to be a suitable option to measure real time the dosimetric properties of narrow pencil proton beams for dose rates up to 2.2 kGy/s.
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Affiliation(s)
- M Togno
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland.
| | - K P Nesteruk
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - R Schäfer
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland
| | - S Psoroulas
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland
| | - D Meer
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland
| | - M Grossmann
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland
| | - J B Christensen
- Department of Radiation Safety and Security, Paul Scherrer Institut, Villigen, Switzerland
| | - E G Yukihara
- Department of Radiation Safety and Security, Paul Scherrer Institut, Villigen, Switzerland
| | - A J Lomax
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland; Department of Physics, ETH Zurich, Zurich, Switzerland
| | - D C Weber
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland; Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland; Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - S Safai
- Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland
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Maradia V, Colizzi I, Meer D, Weber DC, Lomax AJ, Actis O, Psoroulas S. Universal and dynamic ridge filter for pencil beam scanning particle therapy: a novel concept for ultra-fast treatment delivery. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac9d1f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 10/24/2022] [Indexed: 11/07/2022]
Abstract
Abstract
Objective. In pencil beam scanning particle therapy, a short treatment delivery time is paramount for the efficient treatment of moving targets with motion mitigation techniques (such as breath-hold, rescanning, and gating). Energy and spot position change time are limiting factors in reducing treatment time. In this study, we designed a universal and dynamic energy modulator (ridge filter, RF) to broaden the Bragg peak, to reduce the number of energies and spots required to cover the target volume, thus lowering the treatment time. Approach. Our RF unit comprises two identical RFs placed just before the isocenter. Both RFs move relative to each other, changing the Bragg peak’s characteristics dynamically. We simulated different Bragg peak shapes with the RF in Monte Carlo simulation code (TOPAS) and validated them experimentally. We then delivered single-field plans with 1 Gy/fraction to different geometrical targets in water, to measure the dose delivery time using the RF and compare it with the clinical settings. Main results. Aligning the RFs in different positions produces different broadening in the Bragg peak; we achieved a maximum broadening of 2.5 cm. With RF we reduced the number of energies in a field by more than 60%, and the dose delivery time by 50%, for all geometrical targets investigated, without compromising the dose distribution transverse and distal fall-off. Significance. Our novel universal and dynamic RF allows for the adaptation of the Bragg peak broadening for a spot and/or energy layer based on the requirement of dose shaping in the target volume. It significantly reduces the number of energy layers and spots to cover the target volume, and thus the treatment time. This RF design is ideal for ultra-fast treatment delivery within a single breath-hold (5–10 s), efficient delivery of motion mitigation techniques, and small animal irradiation with ultra-high dose rates (FLASH).
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Borys D, Baran J, Brzezinski KW, Gajewski J, Chug N, Coussat A, Czerwiński E, Dadgar M, Dulski K, Eliyan KV, Gajos A, Kacprzak K, Kapłon Ł, Klimaszewski K, Konieczka P, Kopec R, Korcyl G, Kozik T, Krzemień W, Kumar D, Lomax AJ, McNamara K, Niedźwiecki S, Olko P, Panek D, Parzych S, Del Río EP, Raczyński L, Sharma S, Shivani S, Shopa RY, Skóra T, Skurzok M, Stasica P, Stępień E, Tayefi Ardebili K, Tayefi F, Weber DC, Winterhalter C, Wiślicki W, Moskal P, Rucinski A. ProTheRaMon - a GATE simulation framework for proton therapy range monitoring using PET imaging. Phys Med Biol 2022; 67:224002. [PMID: 36137551 DOI: 10.1088/1361-6560/ac944c] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland. APPROACH The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user's needs and specific settings of a given proton therapy facility and PET scanner design. MAIN RESULTS ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized. SIGNIFICANCE We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github.
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Affiliation(s)
- Damian Borys
- Department of Systems Biology and Engineering, Silesian University of Technology, ul. Akademicka 16, Gliwice, 44-100, POLAND
| | - Jakub Baran
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Karol W Brzezinski
- Institute of Nuclear Physics Polish Academy of Science, Radzikowskiego 152, Krakow, Krakow, Malopolska, 31-342, POLAND
| | - Jan Gajewski
- Institute of Nuclear Physics Polish Academy of Science, Radzikowskiego 152, Krakow, Krakow, Malopolska, 31-342, POLAND
| | - Neha Chug
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, 30-348, POLAND
| | - Aurelien Coussat
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Eryk Czerwiński
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Meysam Dadgar
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Kamil Dulski
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Kavya Valsan Eliyan
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Aleksander Gajos
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Krzysztof Kacprzak
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Łukasz Kapłon
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University in Krakow, Lojasiewicza 11, Krakow, Malopolskie, 31-007, POLAND
| | - Konrad Klimaszewski
- National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Paweł Konieczka
- Department of Complex Systems, National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Renata Kopec
- Institute of Nuclear Physics Polish Academy of Science, Radzikowskiego 152, Krakow, 31-342, POLAND
| | - Grzegorz Korcyl
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Tomasz Kozik
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Wojciech Krzemień
- National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Deepak Kumar
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Antony John Lomax
- Department of Radiation Medicine, Paul Scherrer Institute, CH-5232 Villigen PSI, Villigen, 5232, SWITZERLAND
| | - Keegan McNamara
- Center for Proton Therapy, Paul Scherrer Institute PSI, Forschungsstrasse 111, Villigen, Aargau, 5232, SWITZERLAND
| | - Szymon Niedźwiecki
- Institute of Physics, Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Pawel Olko
- PAN, Institute of Nuclear Physics Polish Academy of Science, ul Radzikowskiego 152, Krakow, Kraków, 31-342, POLAND
| | - Dominik Panek
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Szymon Parzych
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Elena Pérez Del Río
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Lech Raczyński
- National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Sushil Sharma
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Shivani Shivani
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Roman Y Shopa
- National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Tomasz Skóra
- Radiotherapy, Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw, Krakow Branch, Walerego Eljasza, Radzikowskiego 152, Kraków, 31-342, POLAND
| | - Magdalena Skurzok
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Paulina Stasica
- Institute of Nuclear Physics Polish Academy of Science, Radzikowskiego 152, Krakow, PL 31-342, POLAND
| | - Ewa Stępień
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Keyvan Tayefi Ardebili
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Faranak Tayefi
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, SWITZERLAND
| | - Carla Winterhalter
- Paul Scherrer Institute PSI, Forschungsstrasse 111, Villigen, Aargau, 5232, SWITZERLAND
| | - Wojciech Wiślicki
- National Centre for Nuclear Research, 7 Andrzeja Sołtana str., Otwock, 05-400, POLAND
| | - Pawel Moskal
- Jagiellonian University in Krakow Faculty of Physics Astronomy and Applied Computer Science, Łojasiewicza 11, Krakow, Małopolskie, 30-348, POLAND
| | - Antoni Rucinski
- Institute of Nuclear Physics PAS, Radzikowskiego 152, Krakow, 31-342, POLAND
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8
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Comparison of pencil beam and Monte Carlo calculations with ion chamber array measurements for patient-specific quality assurance. RADIATION MEDICINE AND PROTECTION 2022. [DOI: 10.1016/j.radmp.2022.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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9
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Christensen JB, Togno M, Bossin L, Pakari OV, Safai S, Yukihara EG. Improved simultaneous LET and dose measurements in proton therapy. Sci Rep 2022; 12:8262. [PMID: 35585205 PMCID: PMC9117334 DOI: 10.1038/s41598-022-10575-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 04/11/2022] [Indexed: 11/23/2022] Open
Abstract
The objective of this study was to improve the precision of linear energy transfer (LET) measurements using \documentclass[12pt]{minimal}
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\begin{document}$$\text {Al}_2\text {O}_3\text {:C}$$\end{document}Al2O3:C optically stimulated luminescence detectors (OSLDs) in proton beams, and, with that, improve OSL dosimetry by correcting the readout for the LET-dependent ionization quenching. The OSLDs were irradiated in spot-scanning proton beams at different doses for fluence-averaged LET values in the (0.4–6.5) \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {keV}\, \upmu \hbox {m}^{-1}$$\end{document}keVμm-1 range (in water). A commercial automated OSL reader with a built-in beta source was used for the readouts, which enabled a reference irradiation and readout of each OSLD to establish individual corrections. Pulsed OSL was used to separately measure the blue (F-center) and UV (\documentclass[12pt]{minimal}
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\begin{document}$$F^+$$\end{document}F+-center) emission bands of \documentclass[12pt]{minimal}
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\begin{document}$$\text {Al}_2\text {O}_3\text {:C}$$\end{document}Al2O3:C and the ratio between them (UV/blue signal) was used for the LET measurements. The average deviation between the simulated and measured LET values along the central beam axis amounts to 5.5% if both the dose and LET are varied, but the average deviation is reduced to 3.5% if the OSLDs are irradiated with the same doses. With the measurement procedure and automated equipment used here, the variation in the signals used for LET estimates and quenching-corrections is reduced from 0.9 to 0.6%. The quenching-corrected OSLD doses are in agreement with ionization chamber measurements within the uncertainties. The automated OSLD corrections are demonstrated to improve the LET estimates and the ionization quenching-corrections in proton dosimetry for a clinically relevant energy range up to 230 MeV. It is also for the first time demonstrated how the LET can be estimated for different doses.
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Affiliation(s)
- Jeppe Brage Christensen
- Department of Radiation Safety and Security, Paul Scherrer Institute, Villigen PSI, Switzerland.
| | - Michele Togno
- Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Lily Bossin
- Department of Radiation Safety and Security, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Oskari Ville Pakari
- Department of Radiation Safety and Security, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI, Switzerland
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10
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Yukihara E, Christensen J, Togno M. Demonstration of an optically stimulated luminescence (OSL) material with reduced quenching for proton therapy dosimetry: MgB4O7:Ce,Li. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Cohilis M, Hong L, Janssens G, Rossomme S, Sterpin E, Lee JA, Souris K. Development and validation of an automatic commissioning tool for the Monte Carlo dose engine in myQA iON. Phys Med 2022; 95:1-8. [PMID: 35051680 DOI: 10.1016/j.ejmp.2022.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 12/14/2022] Open
Abstract
Independent dose verification with Monte Carlo (MC) simulations is an important feature of proton therapy quality assurance (QA). However, clinical integration of such tools often generates an additional and complex workload for medical physicists. The preparation of the necessary clinical inputs, such as the machine beam model, should therefore be automated. In this work, a methodology for automatic MC commissioning has been devised, validated, and developed into a MATLAB tool for the users of myQA iON, the recent QA platform of IBA Dosimetry. With this workflow, all necessary parameters can easily be tuned using dedicated optimization methods. For the geometrical beam parameters (phase space), the assumption of a single or double Gaussian is made. To model the energy spectrum, a Gaussian function is assumed and parameters are optimized using either MC simulations or a library of pre-computed Bragg peaks. For the absolute dose calibration, commissioning fields can be reproduced with the dose engine to retrieve the necessary parameters. We discuss in a first time the tool efficiency and show that one can optimize all parameters in less than 4 min per energy with excellent accuracy. We then validate a beam model obtained with the tool by simulating homogeneous spread-out Bragg peaks (SOBPs) and patient QA plans previously measured in water. An average range agreement of 0.29 ± 0.34 mm is achieved for the SOBPs while 3%/3 mm local gamma passing rates reach 99.3% on average over all 62 measured patient QA planes, which is well within clinical tolerances.
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Affiliation(s)
- M Cohilis
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique (IREC), MIRO Lab, Brussels, Belgium
| | - L Hong
- University of Florida Proton Therapy Institute, Jacksonville, FL, USA
| | - G Janssens
- Ion Beam Applications, Louvain-la-Neuve, Belgium
| | - S Rossomme
- Ion Beam Applications, Louvain-la-Neuve, Belgium
| | - E Sterpin
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique (IREC), MIRO Lab, Brussels, Belgium; KU Leuven, Department of Oncology, Laboratory of Experimental Radiotherapy, Leuven, Belgium
| | - J A Lee
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique (IREC), MIRO Lab, Brussels, Belgium
| | - K Souris
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique (IREC), MIRO Lab, Brussels, Belgium.
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12
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Moskvin VP, Faught A, Pirlepesov F, Zhao L, Hua CH, Merchant TE. Monte Carlo framework for commissioning a synchrotron-based discrete spot scanning proton beam system and treatment plan verification. Biomed Phys Eng Express 2021; 7. [PMID: 34077921 DOI: 10.1088/2057-1976/ac077a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/02/2021] [Indexed: 11/12/2022]
Abstract
This study aimed to develop a Monte Carlo (MC) framework for commissioning the narrow proton beams (spot size sigma, 5.2 mm 2 mm at isocenter for 69.4 MeV-221.3 MeV for the main beam option and 4.1 mm 1.3 mm for the minibeam option respectively) of a synchrotron-based proton therapy system and design an independent absolute dose calculation engine for intensity-modulated proton treatments. A proton therapy system (Hitachi PROBEAT-V) was simulated using divergent and convergent beam models at the nozzle entrance. The innovative source weighting scheme for the MC simulation with TOPAS (TOol for PArticle Simulations) was implemented using dose output data for the absolute dose calculations. The results of the MC simulation were compared to the experimental data, analyzed and used to commission the treatment planning system. Two MC models, divergent and convergent beams were implemented. The convergent beam model produced a high level of agreement when MC and measurements were analyzed. The beam ellipticity did not result in significant differences between MC simulated and treatment planning system calculated doses. A model of a synchrotron-based spot scanning proton therapy system has been developed and implemented in the TOPAS MC transport code framework. The dose computation engine is useful for treatment plan verification with primary and minibeam beam option.
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Affiliation(s)
- Vadim P Moskvin
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
| | - Austin Faught
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
| | - Fakhriddin Pirlepesov
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
| | - Li Zhao
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
| | - Chia-Ho Hua
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
| | - Thomas E Merchant
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-2794, United States of America
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13
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Winterhalter C, Togno M, Nesteruk KP, Emert F, Psoroulas S, Vidal M, Meer D, Weber DC, Lomax A, Safai S. Faraday cup for commissioning and quality assurance for proton pencil beam scanning beams at conventional and ultra-high dose rates. Phys Med Biol 2021; 66. [PMID: 33906166 DOI: 10.1088/1361-6560/abfbf2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/27/2021] [Indexed: 11/11/2022]
Abstract
Recently, proton therapy treatments delivered with ultra-high dose rates have been of high scientific interest, and the Faraday cup (FC) is a promising dosimetry tool for such experiments. Different institutes use different FC designs, and either a high voltage guard ring, or the combination of an electric and a magnetic field is employed to minimize the effect of secondary electrons. The authors first investigate these different approaches for beam energies of 70, 150, 230 and 250 MeV, magnetic fields between 0 and 24 mT and voltages between -1000 and 1000 V. When applying a magnetic field, the measured signal is independent of the guard ring voltage, indicating that this setting minimizes the effect of secondary electrons on the reading of the FC. Without magnetic field, applying the negative voltage however decreases the signal by an energy dependent factor up to 1.3% for the lowest energy tested and 0.4% for the highest energy, showing an energy dependent response. Next, the study demonstrates the application of the FC up to ultra-high dose rates. FC measurements with cyclotron currents up to 800 nA (dose rates of up to approximately 1000 Gy s-1) show that the FC is indeed dose rate independent. Then, the FC is applied to commission the primary gantry monitor for high dose rates. Finally, short-term reproducibility of the monitor calibration is quantified within single days, showing a standard deviation of 0.1% (one sigma). In conclusion, the FC is a promising, dose rate independent tool for dosimetry up to ultra-high dose rates. Caution is however necessary when using a FC without magnetic field, as a guard ring with high voltage alone can introduce an energy dependent signal offset.
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Affiliation(s)
- C Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Physics Department, ETH Zurich, Switzerland
| | - M Togno
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - K P Nesteruk
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - F Emert
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - S Psoroulas
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - M Vidal
- Institut Mediterraneen de Protontherapie, Centre Antoine Lacassagne, Nice, France
| | - D Meer
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - D C Weber
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Radiation Oncology Department of the University Hospital of Bern, Switzerland.,Radiation Oncology Department of the University Hospital of Zürich, Switzerland
| | - A Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Physics Department, ETH Zurich, Switzerland
| | - S Safai
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
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14
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Christensen JB, Togno M, Nesteruk KP, Psoroulas S, Meer D, Weber DC, Lomax T, Yukihara EG, Safai S. Al 2O 3:C optically stimulated luminescence dosimeters (OSLDs) for ultra-high dose rate proton dosimetry. Phys Med Biol 2021; 66. [PMID: 33571973 DOI: 10.1088/1361-6560/abe554] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/11/2021] [Indexed: 11/11/2022]
Abstract
The response of Al2O3:C optically stimulated luminescence detectors (OSLDs) was investigated in a 250 MeV pencil proton beam. The OSLD response was mapped for a wide range of average dose rates up to 9000 Gy s-1, corresponding to a ∼150 kGy s-1instantaneous dose rate in each pulse. Two setups for ultra-high dose rate (FLASH) experiments are presented, which enable OSLDs or biological samples to be irradiated in either water-filled vials or cylinders. The OSLDs were found to be dose rate independent for all dose rates, with an average deviation <1% relative to the nominal dose for average dose rates of (1-1000) Gy s-1when irradiated in the two setups. A third setup for irradiations in a 9000 Gy s-1pencil beam is presented, where OSLDs are distributed in a 3 × 4 grid. Calculations of the signal averaging of the beam over the OSLDs were in agreement with the measured response at 9000 Gy s-1. Furthermore, a new method was presented to extract the beam spot size of narrow pencil beams, which is in agreement within a standard deviation with results derived from radiochromic films. The Al2O3:C OSLDs were found applicable to support radiobiological experiments in proton beams at ultra-high dose rates.
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Affiliation(s)
| | - Michele Togno
- Center for Proton Therapy, Paul Scherrer Institute, Switzerland
| | | | | | - David Meer
- Center for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, Switzerland
| | - Tony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Switzerland.,Department of Physics, ETH Zurich, Switzerland
| | - Eduardo G Yukihara
- Department of Radiation Safety and Security, Paul Scherrer Institute, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Switzerland
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15
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Nenoff L, Matter M, Amaya EJ, Josipovic M, Knopf AC, Lomax AJ, Persson GF, Ribeiro CO, Visser S, Walser M, Weber DC, Zhang Y, Albertini F. Dosimetric influence of deformable image registration uncertainties on propagated structures for online daily adaptive proton therapy of lung cancer patients. Radiother Oncol 2021; 159:136-143. [PMID: 33771576 DOI: 10.1016/j.radonc.2021.03.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/14/2021] [Accepted: 03/15/2021] [Indexed: 12/25/2022]
Abstract
PURPOSE A major burden of introducing an online daily adaptive proton therapy (DAPT) workflow is the time and resources needed to correct the daily propagated contours. In this study, we evaluated the dosimetric impact of neglecting the online correction of the propagated contours in a DAPT workflow. MATERIAL AND METHODS For five NSCLC patients with nine repeated deep-inspiration breath-hold CTs, proton therapy plans were optimised on the planning CT to deliver 60 Gy-RBE in 30 fractions. All repeated CTs were registered with six different clinically used deformable image registration (DIR) algorithms to the corresponding planning CT. Structures were propagated rigidly and with each DIR algorithm and reference structures were contoured on each repeated CT. DAPT plans were optimised with the uncorrected, propagated structures (propagated DAPT doses) and on the reference structures (ideal DAPT doses), non-adapted doses were recalculated on all repeated CTs. RESULTS Due to anatomical changes occurring during the therapy, the clinical target volume (CTV) coverage of the non-adapted doses reduces on average by 9.7% (V95) compared to an ideal DAPT doses. For the propagated DAPT doses, the CTV coverage was always restored (average differences in the CTV V95 < 1% compared to the ideal DAPT doses). Hotspots were always reduced with any DAPT approach. CONCLUSION For the patients presented here, a benefit of online DAPT was shown, even if the daily optimisation is based on propagated structures with some residual uncertainties. However, a careful (offline) structure review is necessary and corrections can be included in an offline adaption.
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Affiliation(s)
- Lena Nenoff
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland; Department of Physics, ETH Zurich, Switzerland.
| | - Michael Matter
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland; Department of Physics, ETH Zurich, Switzerland
| | | | - Mirjana Josipovic
- Department of Oncology, Rigshospitalet Copenhagen University Hospital, Denmark
| | - Antje-Christin Knopf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Antony John Lomax
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland; Department of Physics, ETH Zurich, Switzerland
| | - Gitte F Persson
- Department of Oncology, Rigshospitalet Copenhagen University Hospital, Denmark; Department of Oncology, Herlev-Gentofte Hospital Copenhagen University Hospital, Denmark; Department of Clinical Medicine, Faculty of Medical Sciences, University of Copenhagen, Denmark
| | - Cássia O Ribeiro
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Sabine Visser
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Marc Walser
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland; Department of Radiation Oncology, University Hospital Zurich, Switzerland; Department of Radiation Oncology, University Hospital Bern, Switzerland
| | - Ye Zhang
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
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16
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Paganetti H, Beltran C, Both S, Dong L, Flanz J, Furutani K, Grassberger C, Grosshans DR, Knopf AC, Langendijk JA, Nystrom H, Parodi K, Raaymakers BW, Richter C, Sawakuchi GO, Schippers M, Shaitelman SF, Teo BKK, Unkelbach J, Wohlfahrt P, Lomax T. Roadmap: proton therapy physics and biology. Phys Med Biol 2021; 66. [DOI: 10.1088/1361-6560/abcd16] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022]
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17
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Arjunan M, Sharma DS, Kaushik S, Krishnan G, Patro KC, Padanthaiyil NM, Rajesh T, Jalali R. A novel hybrid 3D dose reconstruction approach for pre-treatment verification of intensity modulated proton therapy plans. Phys Med Biol 2021; 66:055015. [PMID: 33470967 DOI: 10.1088/1361-6560/abdd8b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIM A novel hybrid three-dimensional (3D) dose reconstruction method, based on planar dose measured at a single shallower depth, was developed for use as patient-specific quality assurance (PSQA) of intensity modulated proton therapy (IMPT) plans. The accuracy, robustness and sensitivity of the presented method were validated for multiple IMPT plans of varying complexities. METHODS AND MATERIALS An in-house MATLAB program was developed to reconstruct 3D dose distribution from the planar dose (GyRBE) measured at 3 g cm-2 depth in water or solid phantom using a MatriXX PT ion chamber array. The presented method was validated extensively for 11 single-field optimization (SFO) and multi-field optimization (MFO) plans on Proteus Plus. A total of 47 reconstructed planar doses at different depths were compared against the corresponding RayStation treatment planning system (TPS) and MatriXX PT measurement using a gamma passing rate (γ%) evaluated for 3%/3 mm. The robustness of the reconstruction method with respect to depth, energy layers, field dimensions and complexities in the spot intensity map (SIM) were analysed and compared against the standard PSQA. The sensitivity of the reconstruction method was tested for plans with intentional errors. RESULTS The presented reconstruction method showed excellent agreement (mean γ% > 98%) and robustness with both TPS-calculated and measured dose planes at all depths (2.97-30 g cm-2), energy layers (82.1-225.5 MeV), field dimensions, target volume (17.7-1000 cm3) and SIMs from both SFO and MFO plans. In comparison to the overall mean ± SD γ% from standard PSQA, the reconstruction method showed reductions in mean γ% within 1% for both standard cubes and clinical plans. The reconstruction method was sensitive enough to detect intentional spot positional errors in a selected energy layer of a plan. CONCLUSION The presented hybrid reconstruction method is sufficiently accurate, robust and sensitive to estimate planar dose at any user-defined depth. It simplifies the measurement setup and eliminates multiple depth measurements.
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Affiliation(s)
- Manikandan Arjunan
- Department of Medical Physics, Apollo Proton Cancer Centre, 100 Feet Road Taramani, Chennai, Tamil Nadu, India
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18
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Aitkenhead AH, Sitch P, Richardson JC, Winterhalter C, Patel I, Mackay RI. Automated Monte-Carlo re-calculation of proton therapy plans using Geant4/Gate: implementation and comparison to plan-specific quality assurance measurements. Br J Radiol 2020; 93:20200228. [PMID: 32726141 PMCID: PMC7548378 DOI: 10.1259/bjr.20200228] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/27/2020] [Accepted: 07/02/2020] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Software re-calculation of proton pencil beam scanning plans provides a method of verifying treatment planning system (TPS) dose calculations prior to patient treatment. This study describes the implementation of AutoMC, a Geant4 v10.3.3/Gate v8.1 (Gate-RTion v1.0)-based Monte-Carlo (MC) system for automated plan re-calculation, and presents verification results for 153 patients (730 fields) planned within year one of the proton service at The Christie NHS Foundation Trust. METHODS A MC beam model for a Varian ProBeam delivery system with four range-shifter options (none, 2 cm, 3 cm, 5 cm) was derived from beam commissioning data and implemented in AutoMC. MC and TPS (Varian Eclipse v13.7) calculations of 730 fields in solid-water were compared to physical plan-specific quality assurance (PSQA) measurements acquired using a PTW Octavius 1500XDR array and PTW 31021 Semiflex 3D ion chamber. RESULTS TPS and MC showed good agreement with array measurements, evaluated using γ analyses at 3%, 3 mm with a 10% lower dose threshold:>94% of fields calculated by the TPS and >99% of fields calculated by MC had γ ≤ 1 for>95% of measurement points within the plane. TPS and MC also showed good agreement with chamber measurements of absolute dose, with systematic differences of <1.5% for all range-shifter options. CONCLUSIONS Reliable independent verification of the TPS dose calculation is a valuable complement to physical PSQA and may facilitate reduction of the physical PSQA workload alongside a thorough delivery system quality assurance programme. ADVANCES IN KNOWLEDGE A Gate/Geant4-based MC system is thoroughly validated against an extensive physical PSQA dataset for 730 clinical fields, showing that clinical implementation of MC for PSQA is feasible.
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Affiliation(s)
| | - Peter Sitch
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | | | | | - Imran Patel
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
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Winterhalter C, Taylor M, Boersma D, Elia A, Guatelli S, Mackay R, Kirkby K, Maigne L, Ivanchenko V, Resch AF, Sarrut D, Sitch P, Vidal M, Grevillot L, Aitkenhead A. Evaluation of GATE-RTion (GATE/Geant4) Monte Carlo simulation settings for proton pencil beam scanning quality assurance. Med Phys 2020; 47:5817-5828. [PMID: 32967037 DOI: 10.1002/mp.14481] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Geant4 is a multi-purpose Monte Carlo simulation tool for modeling particle transport in matter. It provides a wide range of settings, which the user may optimize for their specific application. This study investigates GATE/Geant4 parameter settings for proton pencil beam scanning therapy. METHODS GATE8.1/Geant4.10.3.p03 (matching the versions used in GATE-RTion1.0) simulations were performed with a set of prebuilt Geant4 physics lists (QGSP_BIC, QGSP_BIC_EMY, QGSP_BIC_EMZ, QGSP_BIC_HP_EMZ), using 0.1mm-10mm as production cuts on secondary particles (electrons, photons, positrons) and varying the maximum step size of protons (0.1mm, 1mm, none). The results of the simulations were compared to measurement data taken during clinical patient specific quality assurance at The Christie NHS Foundation Trust pencil beam scanning proton therapy facility. Additionally, the influence of simulation settings was quantified in a realistic patient anatomy based on computer tomography (CT) scans. RESULTS When comparing the different physics lists, only the results (ranges in water) obtained with QGSP_BIC (G4EMStandardPhysics_Option0) depend on the maximum step size. There is clinically negligible difference in the target region when using High Precision neutron models (HP) for dose calculations. The EMZ electromagnetic constructor provides a closer agreement (within 0.35 mm) to measured beam sizes in air, but yields up to 20% longer execution times compared to the EMY electromagnetic constructor (maximum beam size difference 0.79 mm). The impact of this on patient-specific quality assurance simulations is clinically negligible, with a 97% average 2%/2 mm gamma pass rate for both physics lists. However, when considering the CT-based patient model, dose deviations up to 2.4% are observed. Production cuts do not substantially influence dosimetric results in solid water, but lead to dose differences of up to 4.1% in the patient CT. Small (compared to voxel size) production cuts increase execution times by factors of 5 (solid water) and 2 (patient CT). CONCLUSIONS Taking both efficiency and dose accuracy into account and considering voxel sizes with 2 mm linear size, the authors recommend the following Geant4 settings to simulate patient specific quality assurance measurements: No step limiter on proton tracks; production cuts of 1 mm for electrons, photons and positrons (in the phantom and range-shifter) and 10 mm (world); best agreement to measurement data was found for QGSP_BIC_EMZ reference physics list at the cost of 20% increased execution times compared to QGSP_BIC_EMY. For simulations considering the patient CT model, the following settings are recommended: No step limiter on proton tracks; production cuts of 1 mm for electrons, photons and positrons (phantom/range-shifter) and 10 mm (world) if the goal is to achieve sufficient dosimetric accuracy to ensure that a plan is clinically safe; or 0.1 mm (phantom/range-shifter) and 1 mm (world) if higher dosimetric accuracy is needed (increasing execution times by a factor of 2); most accurate results expected for QGSP_BIC_EMZ reference physics list, at the cost of 10-20% increased execution times compared to QGSP_BIC_EMY.
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Affiliation(s)
- Carla Winterhalter
- Division of Cancer Sciences, University of Manchester, Manchester, M13 9PL, UK.,The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - Michael Taylor
- Division of Cancer Sciences, University of Manchester, Manchester, M13 9PL, UK.,The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - David Boersma
- ACMIT Gmbh, Viktor Kaplan-Straße 2, Wiener Neustadt, A-2700, Austria.,EBG MedAustron GmbH, Marie Curie-Straße 5, Wiener Neustadt, A-2700, Austria
| | - Alessio Elia
- EBG MedAustron GmbH, Marie Curie-Straße 5, Wiener Neustadt, A-2700, Austria
| | - Susanna Guatelli
- Centre For Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Ranald Mackay
- Division of Cancer Sciences, University of Manchester, Manchester, M13 9PL, UK.,The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - Karen Kirkby
- Division of Cancer Sciences, University of Manchester, Manchester, M13 9PL, UK.,The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - Lydia Maigne
- Laboratoire de Physique de Clermont, UMR 6533 CNRS - University Clermont Auvergne, Aubière, France
| | - Vladimir Ivanchenko
- CERN, Geneva 23, 1211, Switzerland.,Tomsk State University, Tomsk, 634050, Russia
| | - Andreas F Resch
- Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - David Sarrut
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, Lyon, France
| | - Peter Sitch
- The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - Marie Vidal
- Institut Méditerranéen de Protonthérapie - Centre Antoine Lacassagne - Fédération Claude Lalanne, Nice, 06200, France
| | - Loïc Grevillot
- EBG MedAustron GmbH, Marie Curie-Straße 5, Wiener Neustadt, A-2700, Austria
| | - Adam Aitkenhead
- Division of Cancer Sciences, University of Manchester, Manchester, M13 9PL, UK.,The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
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20
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Sheng Y, Wang W, Huang Z, Wu X, Schlegel N, Zhang Q, Shahnaz K, Zhao J. Development of a Monte Carlo beam model for raster scanning proton beams and dosimetric comparison. Int J Radiat Biol 2020; 96:1435-1442. [PMID: 32816596 DOI: 10.1080/09553002.2020.1812758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To develop a Monte Carlo (MC) beam model for raster scanning proton beams for dose verification purposes. METHODS AND MATERIALS MC program FLUKA was used in the model. The nominal energy, momentum spread and beam angular distribution in the model were determined by matching the simulation profiles with the measured integral depth dose (IDD) and in air spot size. Dosimetric comparison was done by comparing the measured and simulated dose distributions. The 1 D dose profile of cubic Spread Out Bragg Peak (SOBP) plans, and the 2 D dose distribution of previously treated breast cancer patients' clinical plans were measured by using Pinpoint chambers and 2 D array ionization chambers, respectively. Corresponding DICOM plan information was utilized for MC simulation. RESULTS The MC results showed good agreement with measurements for the SOBP plans. The absolute comparison of the absorbed dose difference between the MC and the measurement was 0.93%±0.88%. For the patient plans, the overall passing rate of the gamma index analysis (γ-PR) between the MC simulation and measurement with the 2%-2 mm criteria was 97.78%, and only 1 case had a γ-PR less than 90%. With the 3%-3 mm criteria, γ-PR was never below 99% for all cases with and without the range shifter. CONCLUSIONS This work described a method for adapting a MC simulation model for a raster scanning proton beam. The good concordance between the simulations and measurements shows that the MC model is an accurate and reliable method. It has the potential to be used for patient specific quality assurance (PSQA) to reduce the beam time for the measurements in water.
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Affiliation(s)
- Yinxiangzi Sheng
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Weiwei Wang
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Zhijie Huang
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Xiaodong Wu
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Nicki Schlegel
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Qing Zhang
- Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.,Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Shanghai, China
| | - Kambiz Shahnaz
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.,Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China
| | - Jingfang Zhao
- Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.,Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai, China
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21
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Nenoff L, Matter M, Jarhall AG, Winterhalter C, Gorgisyan J, Josipovic M, Persson GF, Munck af Rosenschold P, Weber DC, Lomax AJ, Albertini F. Daily Adaptive Proton Therapy: Is it Appropriate to Use Analytical Dose Calculations for Plan Adaption? Int J Radiat Oncol Biol Phys 2020; 107:747-755. [DOI: 10.1016/j.ijrobp.2020.03.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/26/2020] [Accepted: 03/27/2020] [Indexed: 12/25/2022]
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22
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Rosas S, Belosi FM, Bizzocchi N, Böhlen T, Zepter S, Morach P, Lomax AJ, Weber DC, Hrbacek J. Benchmarking a commercial proton therapy solution: The Paul Scherrer Institut experience. Br J Radiol 2020; 93:20190920. [PMID: 31944827 PMCID: PMC7066977 DOI: 10.1259/bjr.20190920] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/29/2019] [Accepted: 01/10/2020] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE For the past 20 years, Paul Scherrer Institut (PSI) has treated more than 1500 patients with deep-seated tumors using PSI-Plan, an in-house developed treatment planning system (TPS) used for proton beam scanning proton therapy, in combination with its home-built gantries. The goal of the present work is to benchmark the performance of a new TPS/Gantry system for proton therapy centers which have established already a baseline standard of care. METHODS AND MATERIALS A total of 31 cases (=52 plans) distributed around 7 anatomical sites and 12 indications were randomly selected and re-planned using Eclipse™. The resulting plans were compared with plans formerly optimized in PSI-Plan, in terms of target coverage, plan quality, organ-at-risk (OAR) sparing and number of delivered pencil beams. RESULTS Our results show an improvement on target coverage and homogeneity when using Eclipse™ while PSI-Plan showed superior plan conformity. As for OAR sparing, both TPS achieved the clinical constraints. The number of pencil beams required per plan was on average 3.4 times higher for PSI-Plan. CONCLUSION Both systems showed a good capacity to produce satisfactory plans, with Eclipse™ being able to achieve better target coverage and plan homogeneity without compromising OARs. ADVANCES IN KNOWLEDGE A benchmark between a clinically tested and validated system with a commercial solution is of interest for emerging proton therapy, equipped with commercial systems and no previous experience with proton beam scanning.
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Affiliation(s)
- Sara Rosas
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Francesca M Belosi
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Nicola Bizzocchi
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Till Böhlen
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Stefan Zepter
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Petra Morach
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Antony J Lomax
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Damien C Weber
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
| | - Jan Hrbacek
- Zentrum für Protonentherapie, Paul Scherrer Institut, Villigen, Switzerland
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23
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Winterhalter C, Aitkenhead A, Oxley D, Richardson J, Weber DC, MacKay RI, Lomax AJ, Safai S. Pitfalls in the beam modelling process of Monte Carlo calculations for proton pencil beam scanning. Br J Radiol 2020; 93:20190919. [PMID: 32003576 PMCID: PMC7066947 DOI: 10.1259/bjr.20190919] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/20/2020] [Accepted: 01/24/2020] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Monte Carlo (MC) simulations substantially improve the accuracy of predicted doses. This study aims to determine and quantify the uncertainties of setting up such a MC system. METHODS Doses simulated with two Geant4-based MC calculation codes, but independently tuned to the same beam data, have been compared. Different methods of MC modelling of a pre-absorber have been employed, either modifying the beam source parameters (descriptive) or adding the pre-absorber as a physical component (physical). RESULTS After the independent beam modelling of both systems in water (resulting in excellent range agreement) range differences of up to 3.6/4.8 mm (1.5% of total range) in bone/brain-like tissues were found, which resulted from the use of different mean water ionisation potentials during the energy tuning process. When repeating using a common definition of water, ranges in bone/brain agreed within 0.1 mm and gamma-analysis (global 1%,1mm) showed excellent agreement (>93%) for all patient fields. However, due to a lack of modelling of proton fluence loss in the descriptive pre-absorber, differences of 7% in absolute dose between the pre-absorber definitions were found. CONCLUSION This study quantifies the influence of using different water ionisation potentials during the MC beam modelling process. Furthermore, when using a descriptive pre-absorber model, additional Faraday cup or ionisation chamber measurements with pre-absorber are necessary. ADVANCES IN KNOWLEDGE This is the first study quantifying the uncertainties caused by the MC beam modelling process for proton pencil beam scanning, and a more detailed beam modelling process for MC simulations is proposed to minimise the influence of critical parameters.
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Affiliation(s)
| | | | - David Oxley
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Jenny Richardson
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | | | | | | | - Sairos Safai
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
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24
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Platform for automatic patient quality assurance via Monte Carlo simulations in proton therapy. Phys Med 2020; 70:49-57. [PMID: 31968277 DOI: 10.1016/j.ejmp.2019.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/21/2019] [Accepted: 12/18/2019] [Indexed: 12/31/2022] Open
Abstract
For radiation therapy, it is crucial to ensure that the delivered dose matches the planned dose. Errors in the dose calculations done in the treatment planning system (TPS), treatment delivery errors, other software bugs or data corruption during transfer might lead to significant differences between predicted and delivered doses. As such, patient specific quality assurance (QA) of dose distributions, through experimental validation of individual fields, is necessary. These measurement based approaches, however, are performed with 2D detectors, with limited resolution and in a water phantom. Moreover, they are work intensive and often impose a bottleneck to treatment efficiency. In this work, we investigated the potential to replace measurement-based approach with a simulation-based patient specific QA using a Monte Carlo (MC) code as independent dose calculation engine in combination with treatment log files. Our developed QA platform is composed of a web interface, servers and computation scripts, and is capable to autonomously launch simulations, identify and report dosimetric inconsistencies. To validate the beam model of independent MC engine, in-water simulations of mono-energetic layers and 30 SOBP-type dose distributions were performed. Average Gamma passing ratio 99 ± 0.5% for criteria 2%/2 mm was observed. To demonstrate feasibility of the proposed approach, 10 clinical cases such as head and neck, intracranial indications and craniospinal axis, were retrospectively evaluated via the QA platform. The results obtained via QA platform were compared to QA results obtained by measurement-based approach. This comparison demonstrated consistency between the methods, while the proposed approach significantly reduced in-room time required for QA procedures.
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25
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Chen M, Yepes P, Hojo Y, Poenisch F, Li Y, Chen J, Xu C, He X, Gunn GB, Frank SJ, Sahoo N, Li H, Zhu XR, Zhang X. Transitioning from measurement-based to combined patient-specific quality assurance for intensity-modulated proton therapy. Br J Radiol 2019; 93:20190669. [PMID: 31799859 DOI: 10.1259/bjr.20190669] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE This study is part of ongoing efforts aiming to transit from measurement-based to combined patient-specific quality assurance (PSQA) in intensity-modulated proton therapy (IMPT). A Monte Carlo (MC) dose-calculation algorithm is used to improve the independent dose calculation and to reveal the beam modeling deficiency of the analytical pencil beam (PB) algorithm. METHODS A set of representative clinical IMPT plans with suboptimal PSQA results were reviewed. Verification plans were recalculated using an MC algorithm developed in-house. Agreements of PB and MC calculations with measurements that quantified by the γ passing rate were compared. RESULTS The percentage of dose planes that met the clinical criteria for PSQA (>90% γ passing rate using 3%/3 mm criteria) increased from 71.40% in the original PB calculation to 95.14% in the MC recalculation. For fields without beam modifiers, nearly 100% of the dose planes exceeded the 95% γ passing rate threshold using the MC algorithm. The model deficiencies of the PB algorithm were found in the proximal and distal regions of the SOBP, where MC recalculation improved the γ passing rate by 11.27% (p < 0.001) and 16.80% (p < 0.001), respectively. CONCLUSIONS The MC algorithm substantially improved the γ passing rate for IMPT PSQA. Improved modeling of beam modifiers would enable the use of the MC algorithm for independent dose calculation, completely replacing additional depth measurements in IMPT PSQA program. For current users of the PB algorithm, further improving the long-tail modeling or using MC simulation to generate the dose correction factor is necessary. ADVANCES IN KNOWLEDGE We justified a change in clinical practice to achieve efficient combined PSQA in IMPT by using the MC algorithm that was experimentally validated in almost all the clinical scenarios in our center. Deficiencies in beam modeling of the current PB algorithm were identified and solutions to improve its dose-calculation accuracy were provided.
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Affiliation(s)
- Mei Chen
- Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Pablo Yepes
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Physics and Astronomy Department, Rice University, Houston, Texas, USA
| | - Yoshifumi Hojo
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Falk Poenisch
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Yupeng Li
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jiayi Chen
- Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cheng Xu
- Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaodong He
- Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - G Brandon Gunn
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Steven J Frank
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Narayan Sahoo
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Heng Li
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xiaorong Ronald Zhu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xiaodong Zhang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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26
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Nenoff L, Matter M, Hedlund Lindmar J, Weber DC, Lomax AJ, Albertini F. Daily adaptive proton therapy - the key to innovative planning approaches for paranasal cancer treatments. Acta Oncol 2019; 58:1423-1428. [PMID: 31364904 DOI: 10.1080/0284186x.2019.1641217] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Background: For proton therapy of paranasal tumors, field directions avoiding volumes that might change during therapy are typically used. If the plan is optimized on the daily anatomy using daily adapted proton therapy (DAPT) however, field directions crossing the nasal cavities might be feasible. In this study, we investigated the effectiveness of DAPT for enabling narrow-field treatment approaches. Material and methods: For five paranasal tumor patients, representing a wide patient spectrum, anatomically robust 4-field-star and narrow-field plans were calculated and their robustness to anatomical and setup uncertainties was compared with and without DAPT. Based on the nominal planning CTs, per patient up to 125 simulated CTs (simCTs) with different nasal cavity fillings were created and random translations and rotations due to patient setup uncertainties were further simulated. Plans were recalculated or re-optimized on all error scenarios, representing non-adapted and DAPT fractions, respectively. From these, 100 possible treatments (60 GyRBE, 30 fx) were simulated and changes in integral dose, target and organs at risk (OARs) doses evaluated. Results: In comparison to the 4-field-star approach, the use of narrow-fields reduced integral dose between 29% and 56%. If OARs did not overlap with the target, OAR doses were also reduced. Finally, the significantly reduced target coverage in non-adapted treatments (mean V95 reductions of up to 34%) could be almost fully restored with DAPT in all cases (differences <1%). Conclusions: DAPT was found to be not only an effective way to increase plan robustness to anatomical and positional uncertainties, but also opened the possibility to use improved and more conformal field arrangements.
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Affiliation(s)
- Lena Nenoff
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zurich, Zurich, Switzerland
| | - Michael Matter
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zurich, Zurich, Switzerland
| | - Johanna Hedlund Lindmar
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zurich, Zurich, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland
- Department of Radiation Oncology, University Hospital Bern, Bern, Switzerland
| | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zurich, Zurich, Switzerland
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27
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Trnková P, Knäusl B, Actis O, Bert C, Biegun AK, Boehlen TT, Furtado H, McClelland J, Mori S, Rinaldi I, Rucinski A, Knopf AC. Clinical implementations of 4D pencil beam scanned particle therapy: Report on the 4D treatment planning workshop 2016 and 2017. Phys Med 2018; 54:121-130. [PMID: 30337001 DOI: 10.1016/j.ejmp.2018.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/18/2018] [Accepted: 10/02/2018] [Indexed: 12/14/2022] Open
Abstract
In 2016 and 2017, the 8th and 9th 4D treatment planning workshop took place in Groningen (the Netherlands) and Vienna (Austria), respectively. This annual workshop brings together international experts to discuss research, advances in clinical implementation as well as problems and challenges in 4D treatment planning, mainly in spot scanned proton therapy. In the last two years several aspects like treatment planning, beam delivery, Monte Carlo simulations, motion modeling and monitoring, QA phantoms as well as 4D imaging were thoroughly discussed. This report provides an overview of discussed topics, recent findings and literature review from the last two years. Its main focus is to highlight translation of 4D research into clinical practice and to discuss remaining challenges and pitfalls that still need to be addressed and to be overcome.
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Affiliation(s)
- Petra Trnková
- HollandPTC, P.O. Box 5046, 2600 GA Delft, the Netherlands; Erasmus MC, P.O. Box 5201, 3008 AE Rotterdam, the Netherlands
| | - Barbara Knäusl
- Department of Radiation Oncology, Division of Medical Radiation Physics, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/AKH Vienna, Austria
| | - Oxana Actis
- Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Aleksandra K Biegun
- KVI-Center for Advanced Radiation Technology, University of Groningen, Groningen, the Netherlands
| | - Till T Boehlen
- Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - Hugo Furtado
- Department of Radiation Oncology, Division of Medical Radiation Physics, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/AKH Vienna, Austria
| | - Jamie McClelland
- Centre for Medical Image Computing, Dept. Medical Physics and Biomedical, University College London, London, UK
| | - Shinichiro Mori
- National Institute of Radiological Sciences for Charged Particle Therapy, Chiba, Japan
| | - Ilaria Rinaldi
- Lyon 1 University and CNRS/IN2P3, UMR 5822, 69622 Villeurbanne, France; MAASTRO Clinic, P.O. Box 3035, 6202 NA Maastricht, the Netherlands
| | | | - Antje C Knopf
- University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, Groningen, the Netherlands.
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