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Carpentier EE, McDermott RL, Dunne EM, Camborde MA, Bergman AM, Karan T, Liu MCC, Ma RMK, Mestrovic A. Four-dimensional dose calculations for dynamic tumour tracking with a gimbal-mounted linear accelerator. J Appl Clin Med Phys 2021; 22:16-25. [PMID: 34042251 PMCID: PMC8200513 DOI: 10.1002/acm2.13265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/22/2021] [Accepted: 04/13/2021] [Indexed: 12/04/2022] Open
Abstract
PURPOSE In this study we present a novel method for re-calculating a treatment plan on different respiratory phases by accurately modeling the panning and tilting beam motion during DTT (the "rotation method"). This method is used to re-calculate the dose distribution of a plan on multiple breathing phases to accurately assess the dosimetry. METHODS sIMRT plans were optimized on a breath hold computed tomography (CT) image taken at exhale (BHexhale ) for 10 previous liver stereotactic ablative radiotherapy patients. Our method was used to re-calculate the plan on the inhale (0%) and exhale (50%) phases of the four-dimensional CT (4DCT) image set. The dose distributions were deformed to the BHexhale CT and summed together with proper weighting calculated from the patient's breathing trace. Subsequently, the plan was re-calculated on all ten phases using our method and the dose distributions were deformed to the BHexhale CT and accumulated together. The maximum dose for certain organs at risk (OARs) was compared between calculating on two phases and all ten phases. RESULTS In total, 26 OARs were examined from 10 patients. When the dose was calculated on the inhale and exhale phases six OARs exceeded their dose limit, and when all 10 phases were used five OARs exceeded their limit. CONCLUSION Dynamic tumor tracking plans optimized for a single respiratory phase leave an OAR vulnerable to exceeding its dose constraint during other respiratory phases. The rotation method accurately models the beam's geometry. Using deformable image registration to accumulate dose from all 10 breathing phases provides the most accurate results, however it is a time consuming procedure. Accumulating the dose from two extreme breathing phases (exhale and inhale) and weighting them properly provides accurate results while requiring less time. This approach should be used to confirm the safety of a DTT treatment plan prior to delivery.
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Affiliation(s)
- Emilie E. Carpentier
- Department of Physics and AstronomyUniversity of British ColumbiaVancouverBCCanada
- Department of Medical PhysicsBC Cancer – VancouverVancouverBCCanada
| | | | - Emma M. Dunne
- Radiation OncologyBC Cancer VancouverVancouverBCCanada
| | | | | | - Tania Karan
- Department of Medical PhysicsBC Cancer – VancouverVancouverBCCanada
| | | | - Roy M. K. Ma
- Radiation OncologyBC Cancer VancouverVancouverBCCanada
| | - Ante Mestrovic
- Department of Medical PhysicsBC Cancer – VancouverVancouverBCCanada
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2
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Rostamzadeh M, Ishihara Y, Nakamura M, Popescu IA, Mestrovic A, Gete E, Fedrigo R, Bergman AM. Monte Carlo simulation of 6-MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources. J Appl Clin Med Phys 2020; 21:206-218. [PMID: 33219743 PMCID: PMC7769401 DOI: 10.1002/acm2.13090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/12/2020] [Accepted: 10/06/2020] [Indexed: 12/02/2022] Open
Abstract
The commissioning and benchmark of a Monte Carlo (MC) model of the 6‐MV Brainlab‐Mitsubishi Vero4DRT linear accelerator for the purpose of quality assurance of clinical dynamic wave arc (DWA) treatment plans is reported. Open‐source MC applications based on EGSnrc particle transport codes are used to simulate the medical linear accelerator head components. Complex radiotherapy irradiations can be simulated in a single MC run using a shared library format combined with BEAMnrc “source20.” Electron energy tuning is achieved by comparing measured vs simulated percentage depth doses (PDDs) for MLC‐defined field sizes in a water phantom. Electron spot size tuning is achieved by comparing measured and simulated inplane and crossplane beam profiles. DWA treatment plans generated from RayStation (RaySearch) treatment planning system (TPS) are simulated on voxelized (2.5 mm3) patient CT datasets. Planning target volume (PTV) and organs at risk (OAR) dose–volume histograms (DVHs) are compared to TPS‐calculated doses for clinically deliverable dynamic volumetric modulated arc therapy (VMAT) trajectories. MC simulations with an electron beam energy of 5.9 MeV and spot size FWHM of 1.9 mm had the closest agreement with measurement. DWA beam deliveries simulated on patient CT datasets results in DVH agreement with TPS‐calculated doses. PTV coverage agreed within 0.1% and OAR max doses (to 0.035 cc volume) agreed within 1 Gy. This MC model can be used as an independent dose calculation from the TPS and as a quality assurance tool for complex, dynamic radiotherapy treatment deliveries. Full patient CT treatment simulations are performed in a single Monte Carlo run in 23 min. Simulations are run in parallel using the Condor High‐Throughput Computing software1 on a cluster of eight servers. Each server has two physical processors (Intel Xeon CPU E5‐2650 0 @2.00 GHz), with 8 cores per CPU and two threads per core for 256 calculation nodes.
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Affiliation(s)
- Maryam Rostamzadeh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | - Ante Mestrovic
- Medical Physics Department, BC Cancer-Vancouver, Vancouver, Canada
| | - Ermias Gete
- Medical Physics Department, BC Cancer-Vancouver, Vancouver, Canada
| | - Roberto Fedrigo
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
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Ziegler M, Lettmaier S, Fietkau R, Bert C. Performance of Makerless Tracking for Gimbaled Dynamic Tumor Tracking. Z Med Phys 2019; 30:96-103. [PMID: 31780095 DOI: 10.1016/j.zemedi.2019.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/23/2019] [Accepted: 10/23/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this work is to report the workflow and the accuracy of the new markerless dynamic tumor tracking (MLDTT) method of the Vero 4DRT system introduced with ExacTrac 3.6.1. MATERIAL AND METHODS Phantom measurements were performed to assess the accuracy of the MLDTT algorithm by using the QA-tool which is provided by the vendor. A patient breathing curve was used as the motion trajectory of the phantom and the target positions detected by the MLDTT algorithm were compared to the defined positions. Furthermore, eight patients have been treated with MLDTT between May 2018 and July 2019. A log-file analysis is used to evaluate MLDTT treatment data. RESULTS The accuracy of the MLDTT detection is 0.12mm ± 0.12mm, 0.12mm ± 0.11mm, 0.20mm ± 0.21mm for the x-, y-, z-direction, respectively. These values are comparable to the accuracy of marker based DTT at the Vero system. The median treatment time was 21min 34seconds and 175kV images were acquired during treatment for monitoring the target motion. CONCLUSION The accuracy of the MLDTT algorithm is comparable to the marker based approach and the accuracy reported for the XSight Lung of the CyberKnife. Eight patients were treated successfully using MLDTT and the treatment times are comparable to a standard DTT treatment.
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Affiliation(s)
- Marc Ziegler
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - Sebastian Lettmaier
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany.
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Ziegler M, Brandt T, Lettmaier S, Fietkau R, Bert C. Method for a motion model based automated 4D dose calculation. Phys Med Biol 2019; 64:225002. [PMID: 31618719 DOI: 10.1088/1361-6560/ab4e51] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Vero system can treat intra-fractionally moving tumors with gimbaled dynamic tumor tracking (DTT) by rotating the treatment beam so that it follows the motion of the tumor. However, the changes in the beam geometry and the constant breathing motion of the patient influence the dose applied to the patient. This study aims to perform a full 4D dose reconstruction for thirteen patients treated with DTT at the Vero system at the Universitätsklinikum Erlangen and investigates the temporal resolution required to perform an accurate 4D dose reconstruction. For all patients, a 4DCT was used to train a 4D motion model, which is able to calculate pseudo-CT images for arbitrary breathing phases. A new CT image was calculated for every 100 ms of treatment and a dose calculation was performed according to the current beam geometry (i.e. the rotation of the treatment beam at this moment in time) by rotating according to the momentary beam rotation, which is extracted from log-files. The resulting dose distributions were accumulated on the planning CT and characteristic parameters were extracted and compared. [Formula: see text]-evaluations of dose accumulations with different spatial-temporal resolutions were performed to determine the minimal required resolution. In total 173 700 dose calculations were performed. The accumulated 4D dose distributions show a reduced mean GTV dose of 0.77% compared to the static treatment plan. For some patients larger deviations were observed, especially in the presence of a poor 4DCT quality. The [Formula: see text]-evaluation showed that a temporal resolution of 500 ms is sufficient for an accurate dose reconstruction. If the tumor motion is regarded as well, a spatial-temporal sampling of 1400 ms and 2 mm yields accurate results, which reduces the workload by 84%.
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Affiliation(s)
- Marc Ziegler
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany
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5
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Tachibana H, Uchida Y, Miyakawa R, Yamashita M, Sato A, Kito S, Maruyama D, Noda S, Kojima T, Fukuma H, Shirata R, Okamoto H, Nakamura M, Takada Y, Nagata H, Hayashi N, Takahashi R, Kawai D, Itano M. Multi-institutional comparison of secondary check of treatment planning using computer-based independent dose calculation for non-C-arm linear accelerators. Phys Med 2018; 56:58-65. [PMID: 30527090 DOI: 10.1016/j.ejmp.2018.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/31/2018] [Accepted: 11/15/2018] [Indexed: 10/27/2022] Open
Abstract
PURPOSE This report covers the first multi-institutional study of independent monitor unit (MU)/dose calculation verification for the CyberKnife, Vero4DRT, and TomoTherapy radiotherapy delivery systems. METHODS A total of 973 clinical treatment plans were collected from 12 institutions. Commercial software employing the Clarkson algorithm was used for verification after a measurement validation study, and the doses from the treatment planning systems (TPSs) and verification programs were compared on the basis of the mean value ± two standard deviations. The impact of heterogeneous conditions was assessed in two types of sites: non-lung and lung. RESULTS The dose difference for all locations was 0.5 ± 7.2%. There was a statistically significant difference (P < 0.01) in dose difference between non-lung (-0.3 ± 4.4%) and lung sites (3.5 ± 6.7%). Inter-institutional comparisons showed that various systematic differences were associated with the proportion of different treatment sites and heterogeneity correction. CONCLUSIONS This multi-institutional comparison should help to determine the departmental action levels for CyberKnife, Vero4DRT, and TomoTherapy, as patient populations and treatment sites may vary between the modalities. An action level of ±5% could be considered for intensity-modulated radiation therapy (IMRT), non-IMRT, and volumetric modulated arc radiotherapy using these modalities in homogenous and heterogeneous conditions with a large treatment field applied to a large region of homogeneous media. There were larger systematic differences in heterogeneous conditions with a small treatment field because of differences in heterogeneity correction with the different dose calculation algorithms of the primary TPS and verification program.
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Affiliation(s)
- Hidenobu Tachibana
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 277-8577 Chiba, Japan; Radiation Safety and Quality Assurance Division, Hospital East, National Cancer Center, 277-8577 Chiba, Japan.
| | - Yukihiro Uchida
- Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 277-8577 Chiba, Japan.
| | - Ryuta Miyakawa
- Department of Radiology, Saiseikai Yokohamashi Tobu Hospital, 230-8765 Kanagawa, Japan.
| | - Mikiko Yamashita
- Department of Radiological Technology, Kobe City Medical Center General Hospital, 650-0047 Hyogo, Japan.
| | - Aya Sato
- Department of Radiology, Itabashi Chuo Medical Center, 174-0051 Tokyo, Japan
| | - Satoshi Kito
- Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 113-8677 Tokyo, Japan.
| | - Daiki Maruyama
- Department of Medical Technology, Japanese Red Cross Medical Center, 150-8935 Tokyo, Japan.
| | - Shigetoshi Noda
- Department of Radiology, Kitasato University Hospital, 252-0375 Kanagawa, Japan.
| | - Toru Kojima
- Department of Radiation Oncology, Saitama Cancer Center, 362-0806 Saitama, Japan
| | - Hiroshi Fukuma
- Department of Radiology, Nagoya City University Hospital, 467-8602 Aichi, Japan
| | - Ryosuke Shirata
- Department of Radiation Oncology, Shonan Kamakura General Hospital, 247-8533 Kanagawa, Japan.
| | - Hiroyuki Okamoto
- Department of Radiation Oncology, The National Cancer Center, 104-0045 Tokyo, Japan.
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University, 606-8507 Kyoto, Japan.
| | - Yuma Takada
- Department of Radiology, Ogaki Tokushukai Hospital, 503-0015 Gifu, Japan.
| | - Hironori Nagata
- Department of Radiation Oncology, Shonan Kamakura General Hospital, 247-8533 Kanagawa, Japan
| | - Naoki Hayashi
- School of Health Sciences, Fujita Health University, 470-1192 Aichi, Japan.
| | - Ryo Takahashi
- Department of Radiation Oncology, The Cancer Institute Hospital of Japanese Foundation of Cancer Research, 135-8550 Tokyo, Japan.
| | - Daisuke Kawai
- Division of Radiation Oncology, Kanagawa Cancer Center, 241-0815 Kanagawa, Japan
| | - Masanobu Itano
- Department of Radiation Oncology, Funabashi Municipal Medical Center, 273-8588 Chiba, Japan.
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Nakamura A, Hiraoka M, Itasaka S, Nakamura M, Akimoto M, Ishihara Y, Mukumoto N, Goto Y, Kishi T, Yoshimura M, Matsuo Y, Yano S, Mizowaki T. Evaluation of Dynamic Tumor-tracking Intensity-modulated Radiotherapy for Locally Advanced Pancreatic Cancer. Sci Rep 2018; 8:17096. [PMID: 30459454 PMCID: PMC6244273 DOI: 10.1038/s41598-018-35402-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/05/2018] [Indexed: 12/25/2022] Open
Abstract
Intensity-modulated radiotherapy (IMRT) is now regarded as an important treatment option for patients with locally advanced pancreatic cancer (LAPC). To reduce the underlying tumor motions and dosimetric errors during IMRT as well as the burden of respiratory management for patients, we started to apply a new treatment platform of the dynamic tumor dynamic tumor-tracking intensity-modulated radiotherapy (DTT-IMRT) using the gimbaled linac, which can swing IMRT toward the real-time tumor position under patients' voluntary breathing. Between June 2013 and March 2015, ten patients were treated, and the tumor-tracking accuracy and the practical benefits were evaluated. The mean PTV size in DTT-IMRT was 18% smaller than a conventional ITV-based PTV. The root-mean-squared errors between the predicted and the detected tumor positions were 1.3, 1.2, and 1.5 mm in left-right, anterior-posterior, and cranio-caudal directions, respectively. The mean in-room time was 24.5 min. This high-accuracy of tumor-tracking with reasonable treatment time are promising and beneficial to patients with LAPC.
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Affiliation(s)
- Akira Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
| | - Satoshi Itasaka
- Department of Radiation Oncology, Kurashiki Central Hospital, Kurashiki, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mami Akimoto
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yoshitomo Ishihara
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Nobutaka Mukumoto
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yoko Goto
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takahiro Kishi
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Michio Yoshimura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shinsuke Yano
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Yamashita M, Takahashi R, Kokubo M, Takayama K, Tanabe H, Sueoka M, Ishii M, Tachibana H. A feasibility study of independent verification of dose calculation for Vero4DRT using a Clarkson-based algorithm. Med Dosim 2018; 44:20-25. [PMID: 29395462 DOI: 10.1016/j.meddos.2017.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 12/04/2017] [Accepted: 12/22/2017] [Indexed: 10/17/2022]
Abstract
Dose verification for a gimbal-mounted image-guided radiotherapy system, Vero4DRT (Mitsubishi Heavy Industries Ltd., Tokyo, Japan) is usually carried out by pretreatment measurement. Independent verification calculations using Monte Carlo methods for Vero4DRT have been published. As the Clarkson method is faster and easier to use than measurement and Monte Carlo methods, we evaluated the accuracy of an independent calculation verification program and its feasibility as a secondary check for Vero4DRT. Computed tomography (CT)-based dose calculation was performed using a modified Clarkson-based algorithm. In this study, 120 patients' treatment plans were collected in our institute. The treatments were performed using conventional irradiation for lung and prostate, 3-dimensional (3D) conformal stereotactic body radiotherapy (SBRT) for the lung, and intensity-modulated radiation therapy (IMRT) for the prostate. Differences between the treatment planning system (TPS) and the Clarkson-based independent dose verification software were computed, and confidence limits (CLs, mean ± 2 standard deviation %) for Vero4DRT were compared with the CLs for the C-arms linear accelerators in the previous study. The results of the CLs, the conventional irradiation, SBRT, and IMRT showed 2.2 ± 3.5% (CL of the C-arms linear accelerators: 2.4 ± 5.3%), 1.1 ± 1.7% (-0.3 ± 2.0%), 4.8 ± 3.7% (5.4 ± 5.3%), and -0.5 ± 2.5% (-0.1 ± 3.6%) differences, respectively. The dose disagreement between the TPS and CT-based independent dose verification software was less than the 5% action level of American Association of Physicists in Medicine (AAPM) Task Group 114 (TG114). The CLs for the gimbal-mounted Vero4DRT were similar to the deviations for C-arms linear accelerators.
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Affiliation(s)
- Mikiko Yamashita
- Department of Radiological Technology, Kobe City Medical Center General Hospital, Hyogo 650-0047, Japan; Radiation Oncology Group, Institute of Biomedical Research and Innovation Laboratory, Hyogo 650-0047, Japan
| | - Ryo Takahashi
- Department of Radiation Oncology, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Masaki Kokubo
- Department of Radiation Oncology, Kobe City Medical Center General Hospital, Hyogo 650-0047, Japan
| | - Kenji Takayama
- Department of Radiation Oncology and Image-Applied Medicine Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Hiroaki Tanabe
- Department of Radiological Technology, Kobe City Medical Center General Hospital, Hyogo 650-0047, Japan
| | - Masaki Sueoka
- Department of Radiological Technology, Kobe City Medical Center General Hospital, Hyogo 650-0047, Japan
| | - Masao Ishii
- Department of Radiological Technology, Kobe City Medical Center West Hospital, Hyogo 653-0013, Japan
| | - Hidenobu Tachibana
- Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center, Chiba 277-8577, Japan.
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Prasetio H, Wölfelschneider J, Ziegler M, Serpa M, Witulla B, Bert C. Dose calculation and verification of the Vero gimbal tracking treatment delivery. Phys Med Biol 2018; 63:035043. [PMID: 29311415 DOI: 10.1088/1361-6560/aaa617] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The Vero linear accelerator delivers dynamic tumor tracking (DTT) treatment using a gimbal motion. However, the availability of treatment planning systems (TPS) to simulate DTT is limited. This study aims to implement and verify the gimbal tracking beam geometry in the dose calculation. Gimbal tracking was implemented by rotating the reference CT outside the TPS according to the ring, gantry, and gimbal tracking position obtained from the tracking log file. The dose was calculated using these rotated CTs. The geometric accuracy was verified by comparing calculated and measured film response using a ball bearing phantom. The dose was verified by comparing calculated 2D dose distributions and film measurements in a ball bearing and a homogeneous phantom using a gamma criterion of 2%/2 mm. The effect of implementing the gimbal tracking beam geometry in a 3D patient data dose calculation was evaluated using dose volume histograms (DVH). Geometrically, the gimbal tracking implementation accuracy was <0.94 mm. The isodose lines agreed with the film measurement. The largest dose difference of 9.4% was observed at maximum tilt positions with an isocenter and target separation of 17.51 mm. Dosimetrically, gamma passing rates were >98.4%. The introduction of the gimbal tracking beam geometry in the dose calculation shifted the DVH curves by 0.05%-1.26% for the phantom geometry and by 5.59% for the patient CT dataset. This study successfully demonstrates a method to incorporate the gimbal tracking beam geometry into dose calculations. By combining CT rotation and MU distribution according to the log file, the TPS was able to simulate the Vero tracking treatment dose delivery. The DVH analysis from the gimbal tracking dose calculation revealed changes in the dose distribution during gimbal DTT that are not visible with static dose calculations.
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Affiliation(s)
- H Prasetio
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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Ono T, Miyabe Y, Takahashi K, Akimoto M, Mukumoto N, Ishihara Y, Nakamura M, Mizowaki T, Hiraoka M. Geometric and dosimetric accuracy of dynamic tumor tracking during volumetric-modulated arc therapy using a gimbal mounted linac. Radiother Oncol 2017; 129:166-172. [PMID: 29137808 DOI: 10.1016/j.radonc.2017.10.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE The aim was to examine the feasibility of a dynamic tumor-tracking volumetric modulated arc therapy (DTT-VMAT) technique using a gimbal-mounted linac and assess its positional, mechanical and dosimetric accuracy. MATERIALS AND METHODS DTT-VMAT was performed using a surrogated signal-based technique. The positional tracking accuracy was evaluated as the difference between the predicted and detected target positions for various wave patterns. Mechanical accuracy measurements included gantry, multileaf collimator (MLC) and gimbal positions. The differences between the command and the measured positions were evaluated for various wave patterns. Dosimetric verification was performed using Gafchromic EBT3 films in the benchmark phantom and two clinical cases. RESULTS The root mean square error (RMSE) of the positional accuracy was within 0.31 mm. The RMSE of mechanical accuracy was within 0.14° for the gantry, 0.11 ± 0.02 mm for the MLC and 0.13 mm for the gimbal positions. The passing rate of the 3%/3 mm gamma index was greater than 83.3% and 91.2% for the benchmark phantom and two clinical cases, respectively. CONCLUSIONS The positional, mechanical and dosimetric accuracy of DTT-VMAT were evaluated. DTT-VMAT with a gimbal-mounted linac had sufficient accuracy and presents a new strategy for treatment of several tumors with respiratory motion.
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Affiliation(s)
- Tomohiro Ono
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan; Department of Radiation Oncology, Wakayama Red Cross Hospital, Japan
| | - Yuki Miyabe
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan.
| | - Kunio Takahashi
- Advanced Mechanical Systems Department, Mitsubishi Heavy Industries Ltd, Hiroshima, Japan
| | - Mami Akimoto
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan
| | - Nobutaka Mukumoto
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan
| | - Yoshitomo Ishihara
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Japan; Department of Radiation Oncology, Wakayama Red Cross Hospital, Japan
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10
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Tsuruta Y, Nakamura M, Miyabe Y, Nakata M, Ishihara Y, Mukumoto N, Akimoto M, Ono T, Yano S, Higashimura K, Matsuo Y, Mizowaki T, Hiraoka M. Use of a second-dose calculation algorithm to check dosimetric parameters for the dose distribution of a first-dose calculation algorithm for lung SBRT plans. Phys Med 2017; 44:86-95. [PMID: 28760507 DOI: 10.1016/j.ejmp.2017.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 07/06/2017] [Accepted: 07/22/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To verify lung stereotactic body radiotherapy (SBRT) plans using a secondary treatment planning system (TPS) as an independent method of verification and to define tolerance levels (TLs) in lung SBRT between the primary and secondary TPSs. METHODS A total of 147 lung SBRT plans calculated using X-ray voxel Monte Carlo (XVMC) were exported from iPlan to Eclipse in DICOM format. Dose distributions were recalculated using the Acuros XB (AXB) and the anisotropic analytical algorithm (AAA), while maintaining monitor units (MUs) and the beam arrangement. Dose to isocenter and dose-volumetric parameters, such as D2, D50, D95 and D98, were evaluated for each patient. The TLs of all parameters between XVMC and AXB (TLAXB) and between XVMC and AAA (TLAAA) were calculated as the mean±1.96 standard deviations. RESULTS AXB values agreed with XVMC values within 3.5% for all dosimetric parameters in all patients. By contrast, AAA sometimes calculated a 10% higher dose in PTV D95 and D98 than XVMC. The TLAXB and TLAAA of the dose to isocenter were -0.3±1.4% and 0.6±2.9%, respectively. Those of D95 were 1.3±1.8% and 1.7±3.6%, respectively. CONCLUSIONS This study quantitatively demonstrated that the dosimetric performance of AXB is almost equal to that of XVMC, compared with that of AAA. Therefore, AXB is a more appropriate algorithm for an independent verification method for XVMC.
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Affiliation(s)
- Yusuke Tsuruta
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
| | - Yuki Miyabe
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Manabu Nakata
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507, Japan
| | - Yoshitomo Ishihara
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Nobutaka Mukumoto
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Mami Akimoto
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Tomohiro Ono
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Shinsuke Yano
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507, Japan
| | - Kyoji Higashimura
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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Ishihara Y, Nakamura M, Miyabe Y, Mukumoto N, Matsuo Y, Sawada A, Kokubo M, Mizowaki T, Hiraoka M. Development of a four-dimensional Monte Carlo dose calculation system for real-time tumor-tracking irradiation with a gimbaled X-ray head. Phys Med 2017; 35:59-65. [PMID: 28216331 DOI: 10.1016/j.ejmp.2017.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/13/2017] [Accepted: 02/10/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To develop a four-dimensional (4D) dose calculation system for real-time tumor tracking (RTTT) irradiation by the Vero4DRT. METHODS First, a 6-MV photon beam delivered by the Vero4DRT was simulated using EGSnrc. A moving phantom position was directly measured by a laser displacement gauge. The pan and tilt angles, monitor units, and the indexing time indicating the phantom position were also extracted from a log file. Next, phase space data at any angle were created from both the log file and particle data under the dynamic multileaf collimator. Irradiation both with and without RTTT, with the phantom moving, were simulated using several treatment field sizes. Each was compared with the corresponding measurement using films. Finally, dose calculation for each computed tomography dataset of 10 respiratory phases with the X-ray head rotated was performed to simulate the RTTT irradiation (4D plan) for lung, liver, and pancreatic cancer patients. Dose-volume histograms of the 4D plan were compared with those calculated on the single reference respiratory phase without the gimbal rotation [three-dimensional (3D) plan]. RESULTS Differences between the simulated and measured doses were less than 3% for RTTT irradiation in most areas, except the high-dose gradient. For clinical cases, the target coverage in 4D plans was almost identical to that of the 3D plans. However, the doses to organs at risk in the 4D plans varied at intermediate- and low-dose levels. CONCLUSIONS Our proposed system has acceptable accuracy for RTTT irradiation in the Vero4DRT and is capable of simulating clinical RTTT plans.
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Affiliation(s)
- Yoshitomo Ishihara
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yuki Miyabe
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Nobutaka Mukumoto
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Akira Sawada
- Department of Radiological Technology, Faculty of Medical Science, Kyoto College of Medical Science, Nantan 622-0041, Japan
| | - Masaki Kokubo
- Department of Radiation Oncology, Kobe City Medical Center General Hospital, Kobe 650-0047, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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Sasaki M, Nakata M, Nakamura M, Ishihara Y, Fujimoto T, Tsuruta Y, Yano S, Higashimura K. Dosimetric Verification around High-density Materials for External Beam Radiotherapy. Nihon Hoshasen Gijutsu Gakkai Zasshi 2016; 72:735-45. [PMID: 27647596 DOI: 10.6009/jjrt.2016_jsrt_72.9.735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is generally known that the dose distribution around the high-density materials is not accurate with commercially available radiation treatment planning systems (RTPS). Recently, Acuros XB (AXB) has been clinically available for dose calculation algorithm. The AXB is based on the linear Boltzmann transport equation - the governing equation - that describes the distribution of radiation particles resulting from their interactions with matter. The purpose of this study was to evaluate the dose calculation accuracy around high-density materials for AXB under three X-rays energy on the basis of measured values with EBT3 and compare AXB with various dose calculation algorithms (AAA, XVMC) in RTPS and Monte Carlo. First, two different metals, including titanium and stainless steel, were inserted at the center of a water-equivalent phantom, and the depth dose was measured with EBT3. Next, after a phantom which reproduced the geometry of measurement was virtually created in RTPS, dose distributions were calculated with three commercially available algorithms (AXB, AAA, and XVMC) and MC. The calculated doses were then compared with the measured ones. As a result, compared to other algorithms, it was found that the dose calculation accuracy of AXB at the exit side of high-density materials was comparable to that of MC and measured value with EBT3. However, note that AXB underestimated the dose up to approximately 30% at the plane of incidence because it cannot exactly estimate the impact of the backscatter.
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Affiliation(s)
- Makoto Sasaki
- Division of Clinical Radiology Service, Kyoto University Hospital
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Iizuka Y, Matsuo Y, Ishihara Y, Akimoto M, Tanabe H, Takayama K, Ueki N, Yokota K, Mizowaki T, Kokubo M, Hiraoka M. Dynamic tumor-tracking radiotherapy with real-time monitoring for liver tumors using a gimbal mounted linac. Radiother Oncol 2015; 117:496-500. [PMID: 26362722 DOI: 10.1016/j.radonc.2015.08.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 08/24/2015] [Accepted: 08/30/2015] [Indexed: 12/21/2022]
Abstract
PURPOSE Dynamic tumor-tracking stereotactic body radiotherapy (DTT-SBRT) for liver tumors with real-time monitoring was carried out using a gimbal-mounted linear accelerator and the efficacy of the system was determined. In addition, four-dimensional (4D) dose distribution, tumor-tracking accuracy, and tumor-marker positional variations were evaluated. MATERIALS AND METHODS A fiducial marker was implanted near the tumor prior to treatment planning. The prescription dose at the isocenter was 48-60 Gy, delivered in four or eight fractions. The 4D dose distributions were calculated with a Monte Carlo method and compared to the static SBRT plan. The intrafractional errors between the predicted target positions and the actual target positions were calculated. RESULTS Eleven lesions from ten patients were treated successfully. DTT-SBRT allowed an average 16% reduction in the mean liver dose compared to static SBRT, without altering the target dose. The average 95th percentiles of the intrafractional prediction errors were 1.1, 2.3, and 1.7 mm in the left-right, cranio-caudal, and anterior-posterior directions, respectively. After a median follow-up of 11 months, the local control rate was 90%. CONCLUSIONS Our early experience demonstrated the dose reductions in normal tissues and high accuracy in tumor tracking, with good local control using DTT-SBRT with real-time monitoring in the treatment of liver tumors.
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Affiliation(s)
- Yusuke Iizuka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan.
| | - Yoshitomo Ishihara
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Mami Akimoto
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Hiroaki Tanabe
- Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Kenji Takayama
- Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Nami Ueki
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Kenji Yokota
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Masaki Kokubo
- Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe, Japan; Department of Radiation Oncology, Kobe City Medical Center General Hospital, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
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