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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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Janson M, Glimelius L, Fredriksson A, Traneus E, Engwall E. Treatment planning of scanned proton beams in RayStation. Med Dosim 2023; 49:2-12. [PMID: 37996354 DOI: 10.1016/j.meddos.2023.10.009] [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: 09/07/2023] [Revised: 10/17/2023] [Accepted: 10/22/2023] [Indexed: 11/25/2023]
Abstract
The use of scanned proton beams in external beam radiation therapy has seen a rapid development over the past decade. This technique places new demands on treatment planning, as compared to conventional photon-based radiation therapy. In this article, several proton specific functions as implemented in the treatment planning system RayStation are presented. We will cover algorithms for energy layer and spot selection, basic optimization including the handling of spot weight limits, optimization of the linear energy transfer (LET) distribution, robust optimization including the special case of 4D optimization, proton arc planning, and automatic planning using deep learning. We will further present the Monte Carlo (MC) proton dose engine in RayStation to some detail, from the material interpretation of the CT data, through the beam model parameterization, to the actual MC transport mechanism. Useful tools for plan evaluation, including robustness evaluation, and the versatile scripting interface are also described. The overall aim of the paper is to give an overview of some of the key proton planning functions in RayStation, with example usages, and at the same time provide the details about the underlying algorithms that previously have not been fully publicly available.
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Kugel F, Wulff J, Bäumer C, Janson M, Kretschmer J, Brodbek L, Behrends C, Verbeek N, Looe HK, Poppe B, Timmermann B. Validating a double Gaussian source model for small proton fields in a commercial Monte-Carlo dose calculation engine. Z Med Phys 2023; 33:529-541. [PMID: 36577626 PMCID: PMC10751706 DOI: 10.1016/j.zemedi.2022.11.011] [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: 02/19/2022] [Revised: 11/13/2022] [Accepted: 11/28/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE The primary fluence of a proton pencil beam exiting the accelerator is enveloped by a region of secondaries, commonly called "spray". Although small in magnitude, this spray may affect dose distributions in pencil beam scanning mode e.g., in the calculation of the small field output, if not modelled properly in a treatment planning system (TPS). The purpose of this study was to dosimetrically benchmark the Monte Carlo (MC) dose engine of the RayStation TPS (v.10A) in small proton fields and systematically compare single Gaussian (SG) and double Gaussian (DG) modeling of initial proton fluence providing a more accurate representation of the nozzle spray. METHODS The initial proton fluence distribution for SG/DG beam modeling was deduced from two-dimensional measurements in air with a scintillation screen with electronic readout. The DG model was either based on direct fits of the two Gaussians to the measured profiles, or by an iterative optimization procedure, which uses the measured profiles to mimic in-air scan-field factor (SF) measurements. To validate the DG beam models SFs, i.e. relative doses to a 10 × 10 cm2 field, were measured in water for three different initial proton energies (100MeV, 160MeV, 226.7MeV) and square field sizes from 1×1cm2 to 10×10cm2 using a small field ionization chamber (IBA CC01) and an IBA ProteusPlus system (universal nozzle). Furthermore, the dose to the center of spherical target volumes (diameters: 1cm to 10cm) was determined using the same small volume ionization chamber (IC). A comprehensive uncertainty analysis was performed, including estimates of influence factors typical for small field dosimetry deduced from a simple two-dimensional analytical model of the relative fluence distribution. Measurements were compared to the predictions of the RayStation TPS. RESULTS SFs deviated by more than 2% from TPS predictions in all fields <4×4cm2 with a maximum deviation of 5.8% for SG modeling. In contrast, deviations were smaller than 2% for all field-sizes and proton energies when using the directly fitted DG model. The optimized DG model performed similarly except for slightly larger deviations in the 1×1cm2 scan-fields. The uncertainty estimates showed a significant impact of pencil beam size variations (±5%) resulting in up to 5.0% standard uncertainty. The point doses within spherical irradiation volumes deviated from calculations by up to 3.3% for the SG model and 2.0% for the DG model. CONCLUSION Properly representing nozzle spray in RayStation's MC-based dose engine using a DG beam model was found to reduce the deviation to measurements in small spherical targets to below 2%. A thorough uncertainty analysis shows a similar magnitude for the combined standard uncertainty of such measurements.
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Affiliation(s)
- Fabian Kugel
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany; Faculty of Physics, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
| | - Jörg Wulff
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany; Department of Physics, TU Dortmund University, Dortmund, Germany
| | | | - Jana Kretschmer
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl-von-Ossietzky University, Oldenburg, Germany; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Leonie Brodbek
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl-von-Ossietzky University, Oldenburg, Germany; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; EBG MedAustron GmbH, Marie Curie-Straße 5, A-2700, Wiener Neustadt, Austria
| | - Carina Behrends
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany; Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Nico Verbeek
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany
| | - Hui Khee Looe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl-von-Ossietzky University, Oldenburg, Germany
| | - Björn Poppe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl-von-Ossietzky University, Oldenburg, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; University Hospital Essen, Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, Essen, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany
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Argota-Perez R, Sharma MB, Elstrøm UV, Møller DS, Grau C, Jensen K, Holm AIS, Korreman SS. Dose and robustness comparison of nominal, daily and accumulated doses for photon and proton treatment of sinonasal cancer. Radiother Oncol 2022; 173:102-108. [PMID: 35667574 DOI: 10.1016/j.radonc.2022.05.038] [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: 10/04/2021] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The aim was to evaluate and compare the dosimetric effect and robustness towards day-to-day anatomical and setup variations in the delivered dose for photon and proton treatments of sinonasal cancer (SNC) patients. MATERIALS AND METHODS Photon (VMAT) and proton (IMPT) plans were optimized retrospectively for 24 SNC patients. Synthetic CTs (synCT) were obtained by deforming the planning CT (pCT) to the anatomy of every daily cone-beam CT. Both VMAT and IMPT plans were recalculated on the synCTs. The recalculated daily dose was accumulated over the whole treatment on the pCT. Target coverage and dose to organs and risk (OARs) were evaluated for all patients for the nominal, daily and accumulated dose distribution. RESULTS In general, dose to OARs farther away from the target, including brain, chiasm and contralateral optic nerve, was lower for proton plans than photon plans. Whereas, OARs in proximity of the target received a lower dose for photon plans. For proton plans, the target coverage (volume of CTV receiving 95% of prescribed dose), V95%, fell below 99% for 9/24 patients in one or more fractions. For photon plans, 4/24 patients had one or more fractions where V95% fell below 99%. For accumulated doses, V95% was below 99% only in two cases, but above 98% for all patients. CONCLUSION Photon and proton treatment have different strengths regarding OAR sparing. The robustness was high for both treatment modalities. Patient selection for either proton or photon radiation therapy of SNC patients should be based on a case-by-case comparison.
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Affiliation(s)
- R Argota-Perez
- Department of Oncology, Aarhus University Hospital, Denmark
| | - M B Sharma
- Department of Oncology, Aarhus University Hospital, Denmark
| | - U V Elstrøm
- Danish Center for Particle Therapy, Aarhus University Hospital, Denmark
| | - D S Møller
- Department of Oncology, Aarhus University Hospital, Denmark
| | - C Grau
- Department of Oncology, Aarhus University Hospital, Denmark; Danish Center for Particle Therapy, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
| | - K Jensen
- Danish Center for Particle Therapy, Aarhus University Hospital, Denmark
| | - A I S Holm
- Department of Oncology, Aarhus University Hospital, Denmark.
| | - S S Korreman
- Department of Oncology, Aarhus University Hospital, Denmark; Danish Center for Particle Therapy, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
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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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Setianegara J, Mazur TR, Hao Y, Yang D, Harold Li H. Development of a storage phosphor imaging system for proton pencil beam spot profile determination. Med Phys 2021; 48:5459-5471. [PMID: 34318488 DOI: 10.1002/mp.15139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/23/2021] [Accepted: 07/15/2021] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Accurate two-dimensional (2D) profile measurements at submillimeter precision are necessary for proton beam commissioning and periodic quality assurance (QA) purposes and are currently performed at our institution with a commercial scintillation detector (Lynx PT) with limited means for independent checks. The purpose of this work was to create an independent dosimetry system consisting of an in-house optical scanner and a BaFBrI:Eu2+ storage phosphor dosimeter by: (a) determining the optimal settings for the optical scanner, (b) measuring 2D proton spot profiles with the storage phosphors, and (c) comparing them to similar measurements using a commercial scintillation detector. METHODS An in-house 2D laboratory optical scanner was constructed and spatially calibrated for accurate 2D photostimulated luminescence (PSL) dosimetry. Square 5 × 5 cm2 BaFBrI:Eu2+ dosimeter samples were uniformly irradiated with line scans performed to determine the physical and electronic scanner settings resulting in the highest signal-to-noise ratios (SNR) at a sub-millimeter spatial resolution. The resultant spatial resolution of the scanner was then quantitatively assessed by measuring (a) line pairs on a standard X-ray lead bar phantom and (b) modulation transfer functions. Following this, 2D proton spot profiles from a Mevion S250i Hyperscan proton unit were obtained at 1, 10, 20, 30, 40, and 50 monitor unit (MU) settings at maximum energy (E0 = 227.1 MeV) and compared to baseline profiles from a commercial scintillation detector, where 1 MU is calibrated to deliver 1 Gy absolute proton dose-to-water under reference conditions, that is, 41 × 41 proton spots uniformly spaced by 0.25 cm within a 10 × 10 cm2 square field size at maximum energy (227.1 MeV) in water at depth of 5 cm at isocenter. The dosimetric system's sensitivities to (a) ±1 mm positional shifts and (b) ±0.3 mm beam lateral spread changes were quantitatively evaluated through a Gaussian fitting of the crossline and inline plots of the respective artificially shifted beam profiles. RESULTS The physical scanner settings of (a) Δτ = 27 ms time interval between data samples, (b) vx = 1.235 cm/s scanning speed, (c) 1% laser transmission (0.02 mW power) and (d) (Δx, Δy) = (0.33, 0.50 mm) pixel sizes with electronic settings of (a) 300 microseconds time constant, (b) normal dynamic reserve, (c) 24 dB/oct low pass filter slope, and (d) 160 Hz chopping frequency resulted in the highest SNR while maintaining sub-millimeter spatial resolution. The BaFBr0.85 I0.15 :Eu2+ storage phosphor dosimeters were linear from 1 to 50 MU and their profiles did not saturate up to 150 MU. The scanner was able to detect lateral displacements of ±1 mm in both the crossline and inline directions and ±0.3 mm beam spread changes that were artificially introduced by varying the incident proton energy. Specific to our proton unit, proton energy changes of ±1 MeV can also be detected indirectly via beam spread measurements. CONCLUSION Our combined dosimetric system including an in-house laboratory optical scanner and reusable BaFBr0.85 I0.15 :Eu2+ storage phosphors demonstrated a sufficient spatial resolution and dosimetric accuracy to support its use as an independent proton spot measurement dosimeter system. Its wide dynamic range allows for other versatile applications such as proton halo measurements.
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Affiliation(s)
- Jufri Setianegara
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Physics, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Thomas R Mazur
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Yao Hao
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Deshan Yang
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - H Harold Li
- Department of Radiation Oncology, University of Kansas School of Medicine, Kansas City, Kansas, USA
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Shang C, Evans G, Rahman M, Lin L. Beam characteristics of the first clinical 360° rotational single gantry room scanning pencil beam proton treatment system and comparisons against a multi‐room system. J Appl Clin Med Phys 2020; 21:266-271. [PMID: 32790244 PMCID: PMC7497910 DOI: 10.1002/acm2.12984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 11/07/2022] Open
Affiliation(s)
- Charles Shang
- South Florida Proton Therapy Institute Delray Beach FL USA
| | - Grant Evans
- South Florida Proton Therapy Institute Delray Beach FL USA
| | | | - Liyong Lin
- Emory Proton Therapy Center Atlanta GA USA
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Rahman M, Brůža P, Langen KM, Gladstone DJ, Cao X, Pogue BW, Zhang R. Characterization of a new scintillation imaging system for proton pencil beam dose rate measurements. ACTA ACUST UNITED AC 2020; 65:165014. [DOI: 10.1088/1361-6560/ab9452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Chang CW, Huang S, Harms J, Zhou J, Zhang R, Dhabaan A, Slopsema R, Kang M, Liu T, McDonald M, Langen K, Lin L. A standardized commissioning framework of Monte Carlo dose calculation algorithms for proton pencil beam scanning treatment planning systems. Med Phys 2020; 47:1545-1557. [PMID: 31945191 DOI: 10.1002/mp.14021] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Treatment planning systems (TPSs) from different vendors can involve different implementations of Monte Carlo dose calculation (MCDC) algorithms for pencil beam scanning (PBS) proton therapy. There are currently no guidelines for validating non-water materials in TPSs. Furthermore, PBS-specific parameters can vary by 1-2 orders of magnitude among different treatment delivery systems (TDSs). This paper proposes a standardized framework on the use of commissioning data and steps to validate TDS-specific parameters and TPS-specific heterogeneity modeling to potentially reduce these uncertainties. METHODS A standardized commissioning framework was developed to commission the MCDC algorithms of RayStation 8A and Eclipse AcurosPT v13.7.20 using water and non-water materials. Measurements included Bragg peak depth-dose and lateral spot profiles and scanning field outputs for Varian ProBeam. The phase-space parameters were obtained from in-air measurements and the number of protons per MU from output measurements of 10 × 10 cm2 square fields at a 2 cm depth. Spot profiles and various PBS field measurements at additional depths were used to validate TPS. Human tissues in TPS, Gammex phantom materials, and artificial materials were used for the TPS benchmark and validation. RESULTS The maximum differences of phase parameters, spot sigma, and divergence between MCDC algorithms are below 4.5 µm and 0.26 mrad in air, respectively. Comparing TPS to measurements at depths, both MC algorithms predict the spot sigma within 0.5 mm uncertainty intervals, the resolution of the measurement device. Beam Configuration in AcurosPT is found to underestimate number of protons per MU by ~2.5% and requires user adjustment to match measured data, while RayStation is within 1% of measurements using Auto model. A solid water phantom was used to validate the range accuracy of non-water materials within 1% in AcurosPT. CONCLUSIONS The proposed standardized commissioning framework can detect potential issues during PBS TPS MCDC commissioning processes, and potentially can shorten commissioning time and improve dosimetric accuracies. Secondary MCDC can be used to identify the root sources of disagreement between primary MCDC and measurement.
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Affiliation(s)
- Chih-Wei Chang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Sheng Huang
- Memorial Sloan Kettering Cancer Center, New York City, NY, 10065, USA
| | - Joseph Harms
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Rongxiao Zhang
- Department of Radiation Oncology, Dartmouth College, Hanover, NH, USA
| | - Anees Dhabaan
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Roelf Slopsema
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Minglei Kang
- New York Proton Center, New York, NY, 10035, USA
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Mark McDonald
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Katja Langen
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Liyong Lin
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
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