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Zhang J, Chen Z, Lei Y, Wen J. A Novel Approach for Position Verification and Dose Calculation through Local MVCT Reconstruction. Diagnostics (Basel) 2024; 14:482. [PMID: 38472954 DOI: 10.3390/diagnostics14050482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Traditional positioning verification using cone-beam computed tomography (CBCT) may incur errors due to potential misalignments between the isocenter of CBCT and the treatment beams in radiotherapy. This study introduces an innovative method for verifying patient positioning in radiotherapy. Initially, the transmission images from an electronic portal imaging device (EPID) are acquired from 10 distinct angles. Utilizing the ART-TV algorithm, a sparse reconstruction of local megavoltage computed tomography (MVCT) is performed. Subsequently, this MVCT is aligned with the planning CT via a three-dimensional mutual information registration technique, pinpointing any patient-positioning discrepancies and facilitating corrective adjustments to the treatment setup. Notably, this approach employs the same radiation source as used in treatment to obtain three-dimensional images, thereby circumventing errors stemming from misalignment between the isocenter of CBCT and the accelerator. The registration process requires only 10 EPID images, and the dose absorbed during this process is included in the total dose calculation. The results show that our method's reconstructed MVCT images fulfill the requirements for registration, and the registration algorithm accurately detects positioning errors, thus allowing for adjustments in the patient's treatment position and precise calculation of the absorbed dose.
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Affiliation(s)
- Jun Zhang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Zerui Chen
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Yuxin Lei
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Junhai Wen
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
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2
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Giovannelli AC, Köthe A, Safai S, Meer D, Zhang Y, Weber DC, Lomax AJ, Fattori G. Exploring beamline momentum acceptance for tracking respiratory variability in lung cancer proton therapy: a simulation study. Phys Med Biol 2023; 68:195013. [PMID: 37652055 DOI: 10.1088/1361-6560/acf5c4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 08/31/2023] [Indexed: 09/02/2023]
Abstract
Objective. Investigating the aspects of proton beam delivery to track organ motion with pencil beam scanning therapy. Considering current systems as a reference, specify requirements for next-generation units aiming at real-time image-guided treatments.Approach. Proton treatments for six non-small cell lung cancer (NSCLC) patients were simulated using repeated 4DCTs to model respiratory motion variability. Energy corrections required for this treatment site were evaluated for different approaches to tumour tracking, focusing on the potential for energy adjustment within beamline momentum acceptance (dp/p). A respiration-synchronised tracking, taking into account realistic machine delivery limits, was compared to ideal tracking scenarios, in which unconstrained energy corrections are possible. Rescanning and the use of multiple fields to mitigate residual interplay effects and dose degradation have also been investigated.Main results. Energy correction requirements increased with motion amplitudes, for all patients and tracking scenarios. Higher dose degradation was found for larger motion amplitudes, rescanning has beneficial effects and helped to improve dosimetry metrics for the investigated limited dp/pof 1.2% (realistic) and 2.4%. The median differences between ideal and respiratory-synchronised tracking show minimal discrepancies, 1% and 5% respectively for dose coverage (CTV V95) and homogeneity (D5-D95). Multiple-field planning improves D5-D95 up to 50% in the most extreme cases while it does not show a significant effect on V95.Significance. This work shows the potential of implementing tumour tracking in current proton therapy units and outlines design requirements for future developments. Energy regulation within momentum acceptance was investigated to tracking tumour motion with respiratory-synchronisation, achieving results in line with the performance of ideal tracking scenarios. ±5% Δp/p would allow to compensate for all range offsets in our NSCLC patient cohort, including breathing variability. However, the realistic momentum of 1.2% dp/prepresentative of existing medical units limitations, has been shown to preserve plan quality.
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Affiliation(s)
- Anna Chiara Giovannelli
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, Switzerland
| | - Andreas Köthe
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - David Meer
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, 8091 Zürich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, Switzerland
| | - Giovanni Fattori
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
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3
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Zhang Y, Trnkova P, Toshito T, Heijmen B, Richter C, Aznar M, Albertini F, Bolsi A, Daartz J, Bertholet J, Knopf A. A survey of practice patterns for real-time intrafractional motion-management in particle therapy. Phys Imaging Radiat Oncol 2023; 26:100439. [PMID: 37124167 PMCID: PMC10133874 DOI: 10.1016/j.phro.2023.100439] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 05/02/2023] Open
Abstract
Background and purpose Organ motion compromises accurate particle therapy delivery. This study reports on the practice patterns for real-time intrafractional motion-management in particle therapy to evaluate current clinical practice and wishes and barriers to implementation. Materials and methods An institutional questionnaire was distributed to particle therapy centres worldwide (7/2020-6/2021) asking which type(s) of real-time respiratory motion management (RRMM) methods were used, for which treatment sites, and what were the wishes and barriers to implementation. This was followed by a three-round DELPHI consensus analysis (10/2022) to define recommendations on required actions and future vision. With 70 responses from 17 countries, response rate was 100% for Europe (23/23 centres), 96% for Japan (22/23) and 53% for USA (20/38). Results Of the 68 clinically operational centres, 85% used RRMM, with 41% using both rescanning and active methods. Sixty-four percent used active-RRMM for at least one treatment site, mostly with gating guided by an external marker. Forty-eight percent of active-RRMM users wished to expand or change their RRMM technique. The main barriers were technical limitations and limited resources. From the DELPHI analysis, optimisation of rescanning parameters, improvement of motion models, and pre-treatment 4D evaluation were unanimously considered clinically important future focus. 4D dose calculation was identified as the top requirement for future commercial treatment planning software. Conclusion A majority of particle therapy centres have implemented RRMM. Still, further development and clinical integration were desired by most centres. Joint industry, clinical and research efforts are needed to translate innovation into efficient workflows for broad-scale implementation.
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Affiliation(s)
- Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Petra Trnkova
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Toshiyuki Toshito
- Nagoya Proton Therapy Center, Nagoya City University West Medical Center, Nagoya, Japan
| | - Ben Heijmen
- Department of Radiotherapy, Erasmus University Medical Center (Erasmus MC), Rotterdam, the Netherlands
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Marianne Aznar
- Faculty of Biology, Medicine and Health, Division of Cancer Sciences, University of Manchester, United Kingdom
| | | | - Alexandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Juliane Daartz
- F. Burr Proton Therapy, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - Jenny Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Antje Knopf
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Institute for Medical Engineering and Medical Informatics, School of Life Science FHNW, Muttenz, Switzerland
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4
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Duetschler A, Prendi J, Safai S, Weber DC, Lomax AJ, Zhang Y. Limitations of phase-sorting based pencil beam scanned 4D proton dose calculations under irregular motion. Phys Med Biol 2022; 68. [PMID: 36571234 DOI: 10.1088/1361-6560/aca9b6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/07/2022] [Indexed: 12/12/2022]
Abstract
Objective.4D dose calculation (4DDC) for pencil beam scanned (PBS) proton therapy is typically based on phase-sorting of individual pencil beams onto phases of a single breathing cycle 4DCT. Understanding the dosimetric limitations and uncertainties of this approach is essential, especially for the realistic treatment scenario with irregular free breathing motion.Approach.For three liver and three lung cancer patient CTs, the deformable multi-cycle motion from 4DMRIs was used to generate six synthetic 4DCT(MRI)s, providing irregular motion (11/15 cycles for liver/lung; tumor amplitudes ∼4-18 mm). 4DDCs for two-field plans were performed, with the temporal resolution of the pencil beam delivery (4-200 ms) or with 8 phases per breathing cycle (500-1000 ms). For the phase-sorting approach, the tumor center motion was used to determine the phase assignment of each spot. The dose was calculated either using the full free breathing motion or individually repeating each single cycle. Additionally, the use of an irregular surrogate signal prior to 4DDC on a repeated cycle was simulated. The CTV volume with absolute dose differences >5% (Vdosediff>5%) and differences in CTVV95%andD5%-D95%compared to the free breathing scenario were evaluated.Main results.Compared to 4DDC considering the full free breathing motion with finer spot-wise temporal resolution, 4DDC based on a repeated single 4DCT resulted inVdosediff>5%of on average 34%, which resulted in an overestimation ofV95%up to 24%. However, surrogate based phase-sorting prior to 4DDC on a single cycle 4DCT, reduced the averageVdosediff>5%to 16% (overestimationV95%up to 19%). The 4DDC results were greatly influenced by the choice of reference cycle (Vdosediff>5%up to 55%) and differences due to temporal resolution were much smaller (Vdosediff>5%up to 10%).Significance.It is important to properly consider motion irregularity in 4D dosimetric evaluations of PBS proton treatments, as 4DDC based on a single 4DCT can lead to an underestimation of motion effects.
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Affiliation(s)
- A Duetschler
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland.,Department of Physics, ETH Zürich, 8092 Zürich, CH, Switzerland
| | - J Prendi
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland.,Department of Physics, University of Basel, 4056 Basel, CH, Switzerland
| | - S Safai
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
| | - D 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
| | - A 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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5
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Pakela JM, Knopf A, Dong L, Rucinski A, Zou W. Management of Motion and Anatomical Variations in Charged Particle Therapy: Past, Present, and Into the Future. Front Oncol 2022; 12:806153. [PMID: 35356213 PMCID: PMC8959592 DOI: 10.3389/fonc.2022.806153] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/04/2022] [Indexed: 12/14/2022] Open
Abstract
The major aim of radiation therapy is to provide curative or palliative treatment to cancerous malignancies while minimizing damage to healthy tissues. Charged particle radiotherapy utilizing carbon ions or protons is uniquely suited for this task due to its ability to achieve highly conformal dose distributions around the tumor volume. For these treatment modalities, uncertainties in the localization of patient anatomy due to inter- and intra-fractional motion present a heightened risk of undesired dose delivery. A diverse range of mitigation strategies have been developed and clinically implemented in various disease sites to monitor and correct for patient motion, but much work remains. This review provides an overview of current clinical practices for inter and intra-fractional motion management in charged particle therapy, including motion control, current imaging and motion tracking modalities, as well as treatment planning and delivery techniques. We also cover progress to date on emerging technologies including particle-based radiography imaging, novel treatment delivery methods such as tumor tracking and FLASH, and artificial intelligence and discuss their potential impact towards improving or increasing the challenge of motion mitigation in charged particle therapy.
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Affiliation(s)
- Julia M. Pakela
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
| | - Antje Knopf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department I of Internal Medicine, Center for Integrated Oncology Cologne, University Hospital of Cologne, Cologne, Germany
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
| | - Antoni Rucinski
- Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
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He P, Li Q. Impact of Different Synchrotron Flattop Operation Modes on 4D Dosimetric Uncertainties for Scanned Carbon-Ion Beam Delivery. Front Oncol 2022; 12:806742. [PMID: 35223486 PMCID: PMC8873937 DOI: 10.3389/fonc.2022.806742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/17/2022] [Indexed: 11/25/2022] Open
Abstract
Purpose The characteristic of pulsed beam delivery for synchrotron-based carbon-ion radiotherapy has led to the emergence of many scanning scenarios in order to improve the treatment efficiency and accuracy of moving target volume. Here, we aim to evaluate a novel breathing guidance motion mitigation performance under different synchrotron flattop operation modes in carbon-ion radiotherapy. Methods With the use of twelve 4DCT datasets of lung cancer patients who had been treated with respiratory-gated carbon-ion pencil beam therapy, range-adapted internal target volume (raITV) plans were optimized. Under the fixed flattop with single-energy and extended flattop with multi-energy synchrotron operation modes, the 4D treatments with breathing guidance and free breathing-based gated phase-controlled rescanning (PCR) beam delivery were simulated. Dose metrics (D95 and D5–D95 in clinical target volume (CTV)) and treatment time of the resulting 4D plans were compared. Results The two synchrotron operation modes provided different scanning dynamics. For the free breathing-based PCR method delivered in the extended flattop operation mode, the averaged CTV-D95 values were 90.4% ± 3.7%, 95.4% ± 1.7%, 96.9% ± 1.5%, 97.2% ± 1.5%, and 97.3% ± 1.5% for the 1-scanning, 2-PCR, 4-PCR, 6-PCR, and 8-PCR, respectively. For the breathing guidance-based PCR method delivered in the extended flattop mode, these values were 89.1% ± 4.0%, 97.0% ± 1.4%, 98.2% ± 0.7%, 98.6% ± 0.7%, and 98.9% ± 0.7%, respectively. However, CTV-D95 significantly increased to 98.5% ± 1.0% even with just 1-scanning breathing guidance-based fixed flattop operation mode (p < 0.01). Moreover, there was no significant difference in treatment time among the three technical combinations (p > 0.15). Conclusions The combination of the breathing guidance and PCR methods should be an alternative way for motion mitigation for the fixed flattop synchrotron operation mode. The target dose coverage and homogeneity could be further improved by the combination of the breathing guidance and PCR methods than the traditional PCR-only technology for the extended flattop synchrotron operation mode.
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Affiliation(s)
- Pengbo He
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Qiang Li,
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7
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Lis M, Newhauser W, Donetti M, Wolf M, Steinsberger T, Paz A, Graeff C. Preliminary tests of dosimetric quality and projected therapeutic outcomes of multi-phase 4D radiotherapy with proton and carbon ion beams. Phys Med Biol 2021; 66. [PMID: 34740202 DOI: 10.1088/1361-6560/ac36e7] [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] [Received: 06/16/2021] [Accepted: 11/05/2021] [Indexed: 12/25/2022]
Abstract
Objective. The purpose of this study was to perform preliminary pre-clinical tests to compare the dosimetric quality of two approaches to treating moving tumors with ion beams: synchronously delivering the beam with the motion of a moving planning target volume (PTV) using the recently developed multi-phase 4D dose delivery (MP4D) approach, and asynchronously delivering the ion beam to a motion-encompassing internal tumor volume (ITV) combined with rescanning.Approach. We created 4D optimized treatment plans with proton and carbon ion beams for two patients who had previously received treatment for non-small cell lung cancer. For each patient, we created several treatment plans, using approaches with and without motion mitigation: MP4D, ITV with rescanning, static deliveries to a stationary PTV, and deliveries to a moving tumor without motion compensation. Two sets of plans were optimized with margins or robust uncertainty scenarios. Each treatment plan was delivered using a recently-developed motion-synchronized dose delivery system (M-DDS); dose distributions in water were compared to measurements using gamma index analysis to confirm the accuracy of the calculations. Reconstructed dose distributions on the patient CT were analyzed to assess the dosimetric quality of the deliveries (conformity, uniformity, tumor coverage, and extent of hotspots).Main results. Gamma index analysis pass rates confirmed the accuracy of dose calculations. Dose coverage was >95% for all static and MP4D treatments. The best conformity and the lowest lung doses were achieved with MP4D deliveries. Robust optimization led to higher lung doses compared to conventional optimization for ITV deliveries, but not for MP4D deliveries.Significance. We compared dosimetric quality for two approaches to treating moving tumors with ion beams. Our findings suggest that the MP4D approach, using an M-DDS, provides conformal motion mitigation, with full target coverage and lower OAR doses.
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Affiliation(s)
- Michelle Lis
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, United States of America.,Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.,Department of Electrical Engineering and Information Technology, Technical University of Darmstadt, German
| | - Wayne Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, United States of America.,Department of Radiation Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana, United States of America
| | - Marco Donetti
- Research and Development Department, CNAO National Center for Oncological Hadrontherapy, Pavia, Italy
| | - Moritz Wolf
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Timo Steinsberger
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.,Institute of Condensed Matter Physics, Technical University of Darmstadt, Germany
| | - Athena Paz
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Christian Graeff
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
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Pastor-Serrano O, Habraken S, Lathouwers D, Hoogeman M, Schaart D, Perkó Z. How should we model and evaluate breathing interplay effects in IMPT? Phys Med Biol 2021; 66. [PMID: 34757958 DOI: 10.1088/1361-6560/ac383f] [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: 10/11/2021] [Accepted: 11/10/2021] [Indexed: 11/12/2022]
Abstract
Breathing interplay effects in Intensity Modulated Proton Therapy (IMPT) arise from the interaction between target motion and the scanning beam. Assessing the detrimental effect of interplay and the clinical robustness of several mitigation techniques requires statistical evaluation procedures that take into account the variability of breathing during dose delivery. In this study, we present such a statistical method to model intra-fraction respiratory motion based on breathing signals and assess clinical relevant aspects related to the practical evaluation of interplay in IMPT such as how to model irregular breathing, how small breathing changes affect the final dose distribution, and what is the statistical power (number of different scenarios) required for trustworthy quantification of interplay effects. First, two data-driven methodologies to generate artificial patient-specific breathing signals are compared: a simple sinusoidal model, and a precise probabilistic deep learning model generating very realistic samples of patient breathing. Second, we investigate the highly fluctuating relationship between interplay doses and breathing parameters, showing that small changes in breathing period result in large local variations in the dose. Our results indicate that using a limited number of samples to calculate interplay statistics introduces a bigger error than using simple sinusoidal models based on patient parameters or disregarding breathing hysteresis during the evaluation. We illustrate the power of the presented statistical method by analyzing interplay robustness of 4DCT and Internal Target Volume (ITV) treatment plans for a 8 lung cancer patients, showing that, unlike 4DCT plans, even 33 fraction ITV plans systematically fail to fulfill robustness requirements.
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Affiliation(s)
- Oscar Pastor-Serrano
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Steven Habraken
- Erasmus MC Cancer Institute, University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Danny Lathouwers
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Mischa Hoogeman
- Erasmus MC Cancer Institute, University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Dennis Schaart
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Zoltán Perkó
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
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9
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Lis M, Newhauser W, Donetti M, Wolf M, Steinsberger T, Paz A, Graeff C. Dosimetric Validation of a System to Treat Moving Tumors Using Scanned Ion Beams That Are Synchronized With Anatomical Motion. Front Oncol 2021; 11:712126. [PMID: 34568041 PMCID: PMC8456027 DOI: 10.3389/fonc.2021.712126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/16/2021] [Indexed: 12/25/2022] Open
Abstract
Purpose The purpose of this study was to validate the dosimetric performance of scanned ion beam deliveries with motion-synchronization to heterogenous targets. Methods A 4D library of treatment plans, comprised of up to 10 3D sub-plans, was created with robust and conventional 4D optimization methods. Each sub-plan corresponded to one phase of periodic target motion. The plan libraries were delivered to a test phantom, comprising plastic slabs, dosimeters, and heterogenous phantoms. This phantom emulated range changes that occur when treating moving tumors. Similar treatment plans, but without motion synchronization, were also delivered to a test phantom with a stationary target and to a moving target; these were used to assess how the target motion degrades the quality of dose distributions and the extent to which motion synchronization can improve dosimetric quality. The accuracy of calculated dose distributions was verified by comparison with corresponding measurements. Comparisons utilized the gamma index analysis method. Plan quality was assessed based on conformity, dose coverage, overdose, and homogeneity values, each extracted from calculated dose distributions. Results High pass rates for the gamma index analysis confirmed that the methods used to calculate and reconstruct dose distributions were sufficiently accurate for the purposes of this study. Calculated and reconstructed dose distributions revealed that the motion-synchronized and static deliveries exhibited similar quality in terms of dose coverage, overdose, and homogeneity for all deliveries considered. Motion-synchronization substantially improved conformity in deliveries with moving targets. Importantly, measurements at multiple locations within the target also confirmed that the motion-synchronized delivery system satisfactorily compensated for changes in beam range caused by the phantom motion. Specifically, the overall planning and delivery approach achieved the desired dose distribution by avoiding range undershoots and overshoots caused by tumor motion. Conclusions We validated a dose delivery system that synchronizes the movement of the ion beam to that of a moving target in a test phantom. Measured and calculated dose distributions revealed that this system satisfactorily compensated for target motion in the presence of beam range changes due to target motion. The implication of this finding is that the prototype system is suitable for additional preclinical research studies, such as irregular anatomic motion.
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Affiliation(s)
- Michelle Lis
- Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.,Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States
| | - Wayne Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States.,Department of Radiation Physics, Mary Bird Perkins Cancer Center, Baton Rouge, LA, United States
| | - Marco Donetti
- Research and Development Department, CNAO National Center for Oncological Hadrontherapy, Pavia, Italy
| | - Moritz Wolf
- Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Timo Steinsberger
- Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.,Institute of Condensed Matter Physics, Technical University of Darmstadt, Darmstadt, Germany
| | - Athena Paz
- Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Christian Graeff
- Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
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10
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Krieger M, Giger A, Jud C, Duetschler A, Salomir R, Bieri O, Bauman G, Nguyen D, Cattin PC, Weber DC, Lomax AJ, Zhang Y. Liver-ultrasound-guided lung tumour tracking for scanned proton therapy: a feasibility study. Phys Med Biol 2021; 66:035011. [PMID: 33238246 DOI: 10.1088/1361-6560/abcde6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pencil beam scanned (PBS) proton therapy of lung tumours is hampered by respiratory motion and the motion-induced density changes along the beam path. In this simulation study, we aim to investigate the effectiveness of proton beam tracking for lung tumours both under ideal conditions and in conjunction with a respiratory motion model guided by real-time ultrasound imaging of the liver. Multiple-breathing-cycle 4DMRIs of the thorax and abdominal 2D ultrasound images were acquired simultaneously for five volunteers. Deformation vector fields extracted from the 4DMRI, referred to as ground truth motion, were used to generate 4DCT(MRI) data sets of two lung cancer patients, resulting in 10 data sets with variable motion patterns. Given the 4DCT(MRI) and the corresponding ultrasound images as surrogate data, a patient-specific motion model was built. The model consists of an autoregressive model and Gaussian process regression for the temporal and spatial prediction, respectively. Two-field PBS plans were optimised on the reference CTs, and 4D dose calculations (4DDC) were used to simulate dose delivery for (a) unmitigated motion, (b) ideal 2D and 3D tracking (both beam adaption and 4DDC based on ground truth motion), and (c) realistic 2D and 3D tracking (beam adaption based on motion predictions, 4DDC on ground truth motion). Model-guided tracking retrieved clinically acceptable target dose homogeneity, as seen in a substantial reduction of the D5%-D95% compared to the non-mitigated simulation. Tracking in 2D and 3D resulted in a similar improvement of the dose homogeneity, as did ideal and realistic tracking simulations. In some cases, however, the tracked deliveries resulted in a shift towards higher or lower dose levels, leading to unacceptable target over- or under-coverage. The presented motion modelling framework was shown to be an accurate motion prediction tool for the use in proton beam tracking. Tracking alone, however, may not always effectively mitigate motion effects, making it necessary to combine it with other techniques such as rescanning.
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Affiliation(s)
- Miriam Krieger
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland. Department of Physics, ETH Zurich, Zurich, Switzerland
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11
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Fattori G, Zhang Y, Meer D, Weber DC, Lomax AJ, Safai S. The potential of Gantry beamline large momentum acceptance for real time tumour tracking in pencil beam scanning proton therapy. Sci Rep 2020; 10:15325. [PMID: 32948790 PMCID: PMC7501279 DOI: 10.1038/s41598-020-71821-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/18/2020] [Indexed: 02/01/2023] Open
Abstract
Tumour tracking is an advanced radiotherapy technique for precise treatment of tumours subject to organ motion. In this work, we addressed crucial aspects of dose delivery for its realisation in pencil beam scanning proton therapy, exploring the momentum acceptance and global achromaticity of a Gantry beamline to perform continuous energy regulation with a standard upstream degrader. This novel approach is validated on simulation data from three geometric phantoms of increasing complexity and one liver cancer patient using 4D dose calculations. Results from a standard high-to-low beamline ramping scheme were compared to alternative energy meandering schemes including combinations with rescanning. Target coverage and dose conformity were generally well recovered with tumour tracking even though for particularly small targets, large variations are reported for the different approaches. Meandering in energy while rescanning has a positive impact on target homogeneity and similarly, hot spots outside the targets are mitigated with a relatively fast convergence rate for most tracking scenarios, halving the volume of hot spots after as little as 3 rescans. This work investigates the yet unexplored potential of having a large momentum acceptance in medical beam line, and provides an alternative to take tumour tracking with particle therapy closer to clinical translation.
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Affiliation(s)
- Giovanni Fattori
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland.
| | - Ye Zhang
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - David Meer
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, 8091, Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, 3000, Bern, Switzerland
| | - Antony John Lomax
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Department of Physics, ETH Zurich, 8092, Zurich, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, WMSA/C14, Paul Scherrer Institute, 5232, Villigen, Switzerland
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12
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4D strategies for lung tumors treated with hypofractionated scanning proton beam therapy: Dosimetric impact and robustness to interplay effects. Radiother Oncol 2020; 146:213-220. [DOI: 10.1016/j.radonc.2020.02.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022]
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13
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Scholz M. State-of-the-Art and Future Prospects of Ion Beam Therapy: Physical and Radiobiological Aspects. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020. [DOI: 10.1109/trpms.2019.2935240] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Ricardi U, Maraldo MV, Levis M, Parikh RR. Proton Therapy For Lymphomas: Current State Of The Art. Onco Targets Ther 2019; 12:8033-8046. [PMID: 31632057 PMCID: PMC6781741 DOI: 10.2147/ott.s220730] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/13/2019] [Indexed: 12/19/2022] Open
Abstract
The combination of brief chemo-radiotherapy provides high cure rates and represents the first line of treatment for many lymphoma patients. As a result, a high proportion of long-term survivors may experience treatment-related toxic events many years later. Excess and unintended radiation dose to organs at risk (particularly heart, lungs and breasts) may translate in an increased risk of cardiovascular events and second cancers after a few decades. Minimizing dose to organs at risk is thus pivotal to restrain the risk of long-term complications. Proton therapy, with its peculiar physic properties, may help to better spare organs at risk and consequently to reduce toxicities especially in patients receiving mediastinal radiotherapy. Herein, we review the physical basis of proton therapy and the rationale for its implementation in lymphoma patients, with a detailed description of the clinical data. We also discuss the potential disadvantages and uncertainties of protons that may limit their application and critically review the dosimetric studies comparing the risk of late complications between proton and photon radiotherapy.
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Affiliation(s)
| | - Maja V Maraldo
- Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Mario Levis
- Department of Oncology, University of Torino, Torino, Italy
| | - Rahul R Parikh
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
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15
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Potential for Improvements in Robustness and Optimality of Intensity-Modulated Proton Therapy for Lung Cancer with 4-Dimensional Robust Optimization. Cancers (Basel) 2019; 11:cancers11010035. [PMID: 30609652 PMCID: PMC6356681 DOI: 10.3390/cancers11010035] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/18/2018] [Accepted: 12/30/2018] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Major challenges in the application of intensity-modulated proton therapy (IMPT) for lung cancer patients include the uncertainties associated with breathing motion, its mitigation and its consideration in IMPT optimization. The primary objective of this research was to evaluate the potential of four-dimensional robust optimization (4DRO) methodology to make IMPT dose distributions resilient to respiratory motion as well as to setup and range uncertainties; Methods: The effect of respiratory motion, characterized by different phases of 4D computed tomography (4DCT), was incorporated into an in-house 4DRO system. Dose distributions from multiple setup and range uncertainty scenarios were calculated for each of the ten phases of CT datasets. The 4DRO algorithm optimizes dose distributions to achieve target dose coverage and normal tissue sparing for multiple setup and range uncertainty scenarios as well as for all ten respiratory phases simultaneously. IMPT dose distributions of ten lung cancer patients with different tumor sizes and motion magnitudes were optimized to illustrate our approach and its potential; Results: Compared with treatment plans generated using the conventional planning target volume (PTV)-based optimization and 3D robust optimization (3DRO), plans generated by 4DRO were found to have superior clinical target volume coverage and dose robustness in the face of setup and range uncertainties as well as for respiratory motion. In most of the cases we studied, 4DRO also resulted in more homogeneous target dose distributions. Interestingly, such improvements were found even for cases in which moving diaphragms intruded into the proton beam paths; Conclusion: The incorporation of respiratory motion, along with setup and range uncertainties, into robust optimization, has the potential to improve the resilience of target and normal tissue dose distributions in IMPT plans in the face of the uncertainties considered. Moreover, it improves the optimality of plans compared to PTV-based optimization as well as 3DRO.
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16
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Pepin MD, Tryggestad E, Wan Chan Tseung HS, Johnson JE, Herman MG, Beltran C. A Monte-Carlo-based and GPU-accelerated 4D-dose calculator for a pencil beam scanning proton therapy system. Med Phys 2018; 45:5293-5304. [PMID: 30203550 DOI: 10.1002/mp.13182] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/30/2018] [Accepted: 08/31/2018] [Indexed: 01/16/2023] Open
Abstract
PURPOSE The presence of respiratory motion during radiation treatment leads to degradation of the expected dose distribution, both for target coverage and healthy tissue sparing, particularly for techniques like pencil beam scanning proton therapy which have dynamic delivery systems. While tools exist to estimate this degraded four-dimensional (4D) dose, they typically have one or more deficiencies such as not including the particular effects from a dynamic delivery, using analytical dose calculations, and/or using nonphysical dose-accumulation methods. This work presents a clinically useful 4D-dose calculator that addresses each of these shortcomings. METHODS To quickly compute the 4D dose, the three main tasks of the calculator were run on graphics processing units (GPUs). These tasks were (a) simulating the delivery of the plan using measured delivery parameters to distribute the plan amongst 4DCT phases characterizing the patient breathing, (b) using an in-house Monte Carlo simulation (MC) dose calculator to determine the dose delivered to each breathing phase, and (c) accumulating the doses from the various breathing phases onto a single phase for evaluation. The accumulation was performed by individually transferring the energy and mass of dose-grid subvoxels, a technique that models the transfer of dose in a more physically realistic manner. The calculator was run on three test cases, with lung, esophagus, and liver targets, respectively, to assess the various uncertainties in the beam delivery simulation as well as to characterize the dose-accumulation technique. RESULTS Four-dimensional doses were successfully computed for the three test cases with computation times ranging from 4-6 min on a server with eight NVIDIA Titan X graphics cards; the most time-consuming component was the MC dose engine. The subvoxel-based dose-accumulation technique produced stable 4D-dose distributions at subvoxel scales of 0.5-1.0 mm without impairing the total computation time. The uncertainties in the beam delivery simulation led to moderate variations of the dose-volume histograms for these cases; the variations were reduced by implementing repainting or phase-gating motion mitigation techniques in the calculator. CONCLUSIONS A MC-based and GPU-accelerated 4D-dose calculator was developed to estimate the effects of respiratory motion on pencil beam scanning proton therapy treatments. After future validation, the calculator could be used to assess treatment plans and its quick runtime would make it easily usable in a future 4D-robust optimization system.
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Affiliation(s)
- Mark D Pepin
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Erik Tryggestad
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Hok Seum Wan Chan Tseung
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Jedediah E Johnson
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Michael G Herman
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Chris Beltran
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
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17
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Dabaja BS, Hoppe BS, Plastaras JP, Newhauser W, Rosolova K, Flampouri S, Mohan R, Mikhaeel NG, Kirova Y, Specht L, Yahalom J. Proton therapy for adults with mediastinal lymphomas: the International Lymphoma Radiation Oncology Group guidelines. Blood 2018; 132:1635-1646. [PMID: 30108066 PMCID: PMC6212652 DOI: 10.1182/blood-2018-03-837633] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/19/2018] [Indexed: 12/25/2022] Open
Abstract
Among adult lymphoma survivors, radiation treatment techniques that increase the excess radiation dose to organs at risk (OARs) put patients at risk for increased side effects, especially late toxicities. Minimizing radiation to OARs in adults patients with Hodgkin and non-Hodgkin lymphomas involving the mediastinum is the deciding factor for the choice of treatment modality. Proton therapy may help to reduce the radiation dose to the OARs and reduce toxicities, especially the risks for cardiac morbidity and second cancers. Because proton therapy may have some disadvantages, identifying the patients and the circumstances that may benefit the most from proton therapy is important. We present modern guidelines to identify adult lymphoma patients who may derive the greatest benefit from proton therapy, along with an analysis of the advantages and disadvantages of proton treatment.
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Affiliation(s)
- Bouthaina Shbib Dabaja
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Bradford S Hoppe
- Department of Radiation Oncology, University of Florida, Jacksonville, FL
| | - John P Plastaras
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Wayne Newhauser
- Department of Radiation Physics, University of Louisiana, Baton Rouge, LA
| | - Katerina Rosolova
- Proton Therapy Department, Proton Therapy Center Czech, Prague, Czech Republic
- Department of Oncology, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Stella Flampouri
- Department of Radiation Oncology, University of Florida, Jacksonville, FL
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - N George Mikhaeel
- Department of Radiation Oncology, Guy's and St. Thomas' Hospital, London, United Kingdom
| | - Youlia Kirova
- Department of Radiation Oncology, Institut Curie, Paris, France
| | - Lena Specht
- Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; and
| | - Joachim Yahalom
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY
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18
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Cummings D, Tang S, Ichter W, Wang P, Sturgeon JD, Lee AK, Chang C. Four-dimensional Plan Optimization for the Treatment of Lung Tumors Using Pencil-beam Scanning Proton Radiotherapy. Cureus 2018; 10:e3192. [PMID: 30402360 PMCID: PMC6200439 DOI: 10.7759/cureus.3192] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose This study aimed to evaluate the effectiveness of four-dimensional (4D) robust optimization for proton pencil-beam scanning (PBS) treatment of lung tumors. Patients and methods In seven patients with lung cancer, proton beam therapy was planned using 4D robust optimization over 4D computed tomography (CT) data sets. The gross target volume (GTV) was contoured based on individual breathing phases, and a 5-mm expansion was used to generate the clinical target volume (CTV) for each phase. The 4D optimization was conducted directly on the 4D CT data set. The robust optimization settings included a CT Hounsfield unit (HU) uncertainty of 4% and a setup uncertainty of 5 mm to obtain the CTV. Additional target dose objectives such as those for the internal target volume (ITV) as well as the organ-at-risk (OAR) dose requirements were placed on the average CT. For comparison, three-dimensional (3D) robust optimization was also performed on the average CT. An additional verification 4D CT was performed to verify plan robustness against inter-fractional variations. Results Target coverages were generally higher for 4D optimized plans. The difference was most pronounced for ITV V70Gy when evaluating individual breathing phases. The 4D optimized plans were shown to be able to maintain the ITV coverage at full prescription, while 3D optimized plans could not. More importantly, this difference in ITV V70Gy between the 4D and 3D optimized plans was also consistently observed when evaluating the verification 4D CT, indicating that the 4D optimized plans were more robust against inter-fractional variations. Less difference was seen between the 4D and 3D optimized plans in the lungs criteria: V5Gy and V20Gy. Conclusion The proton PBS treatment plans optimized directly on the 4D CT were shown to be more robust when compared to those optimized on a regular 3D CT. Robust 4D optimization can improve the target coverage for the proton PBS lung treatments.
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Affiliation(s)
| | - Shikui Tang
- Medical Physics, Texas Center for Proton Therapy, Irving, USA
| | | | - Peng Wang
- Physics, Texas Center for Proton Therapy, Irving, USA
| | | | - Andrew K Lee
- Radiation Oncology, Texas Center for Proton Therapy, Irving, USA
| | - Chang Chang
- Medical Physics, Texas Center for Proton Therapy, Irving, USA
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19
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Engwall E, Fredriksson A, Glimelius L. 4D robust optimization including uncertainties in time structures can reduce the interplay effect in proton pencil beam scanning radiation therapy. Med Phys 2018; 45:4020-4029. [PMID: 30014478 DOI: 10.1002/mp.13094] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 07/04/2018] [Accepted: 07/04/2018] [Indexed: 02/28/2024] Open
Abstract
PURPOSE Interplay effects in proton radiotherapy can create large distortions in the dose distribution and severely degrade the plan quality. Standard methods to mitigate these effects include abdominal compression, gating, and rescanning. We propose a new method to include the time structures of the delivery and organ motion in the framework of four-dimensional (4D) robust optimization to generate plans that are robust against interplay effects. METHODS The method considers multiple scenarios reflecting the uncertainties in the delivery and in the organ motion. In each scenario, the pencil beam scanning spots are distributed to different phases of the breathing cycle according to each individual spot time stamp, and a partial beam dose is calculated for each phase. The partial beam doses are accumulated on a reference phase through deformable image registrations. Minimax optimization is performed to take all scenarios into account simultaneously. For simplicity, the uncertainties in this proof of concept study are limited to variations in the breathing pattern. The method is evaluated for three different nonsmall cell lung cancer patients and compared to plans using conventional 4D robust optimization both with and without rescanning. We assess the ability of the method to mitigate distortions from the interplay effect over multiple evaluation scenarios using 4D dose calculations. This interplay evaluation is performed in an experimentally validated framework, which is independent of the optimization in the plan generation step. RESULTS For the three studied patients, 4D optimization including time structures is efficient, especially for large tumor motions, where rescanning of conventional 4D robustly optimized plans is not sufficient to mitigate the interplay effect. The most efficient approach of the new method is achieved when it is combined with rescanning. For the patient with the largest motion, the mean V95% is 99.2% and mean V107% is 3.65% for the best rescanned 4D plan optimized with time structure. This can be compared to conventional 4D optimized plans with mean V95% of 92.7% and mean V107% of 13.1%. CONCLUSIONS The current study shows the potential of reducing interplay effects in proton pencil beam scanning radiotherapy by incorporating organ motion and delivery characteristics in a 4D robust optimization.
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Affiliation(s)
- Erik Engwall
- RaySearch Laboratories, Sveavägen 44, Stockholm, SE-111 34, Sweden
| | | | - Lars Glimelius
- RaySearch Laboratories, Sveavägen 44, Stockholm, SE-111 34, Sweden
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20
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Batista V, Richter D, Chaudhri N, Naumann P, Herfarth K, Jäkel O. Significance of intra-fractional motion for pancreatic patients treated with charged particles. Radiat Oncol 2018; 13:120. [PMID: 29941049 PMCID: PMC6020245 DOI: 10.1186/s13014-018-1060-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 06/13/2018] [Indexed: 12/30/2022] Open
Abstract
Background Uncertainties associated with the delivery of treatment to moving organs might compromise the accuracy of treatment. This study explores the impact of intra-fractional anatomical changes in pancreatic patients treated with charged particles delivered using a scanning beam. The aim of this paper is to define the potential source of uncertainties, quantify their effect, and to define clinically feasible strategies to reduce them. Methods The study included 14 patients treated at our facility with charged particles (protons or 12C) using intensity modulated particle therapy (IMPT). Treatment plans were optimized using the Treatment Planning System (TPS) Syngo® RT Planning. The pre-treatment dose distribution under motion (4D) was simulated using the TPS TRiP4D and the dose delivered for some of the treatment fractions was reconstructed. The volume receiving at least 95% of the prescribed dose (V95CTV) and the target dose homogeneity were evaluated. The results from the 4D dose calculations were compared with dose distributions in the static case and its variation correlated with the internal motion amplitude and plan modulation, through the Pearson correlation coefficient, as well the significant p-value. The concept of the modulation index (MI) was introduced to assess the degree of modulation of IMPT plans, through the quantification of intensity gradients between neighboring pencil beams. Results The induced breathing motion together with dynamic beam delivery results in an interplay effect, which affects the homogeneity and target coverage of the dose distribution. This effect is stronger (∆V95CTV > 10%) for patients with tumor motion amplitude above 5 mm and a highly modulated dose distribution between and within fields. The MI combined with the internal motion amplitude is shown to correlate with the target dose degradation and a lack of plan robustness against range and positioning uncertainties. Conclusions Under internal motion the use of inhomogeneous plans results in a decrease in the dose homogeneity and target coverage of dose distributions in comparison to the static case. Plan robustness can be improved by using multiple beams and avoiding beam entrance directions susceptible to density changes. 4D dose calculations support the selection of the most suitable plan for the specific patient’s anatomy. Electronic supplementary material The online version of this article (10.1186/s13014-018-1060-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vania Batista
- Heidelberg University Hospital, Heidelberg, Germany. .,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany. .,RadioOnkologie und Strahlentherapie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| | - Daniel Richter
- Erlangen University Hospital, Erlangen, Germany.,GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Naved Chaudhri
- Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Patrick Naumann
- Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Klaus Herfarth
- Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Oliver Jäkel
- Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany.,German Cancer Research Center, Div. Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
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21
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Bert C, Herfarth K. Management of organ motion in scanned ion beam therapy. Radiat Oncol 2017; 12:170. [PMID: 29110693 PMCID: PMC5674859 DOI: 10.1186/s13014-017-0911-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022] Open
Abstract
Scanned ion beam therapy has special demands for treatment of intra-fractionally moving tumors such as lesions in lung or liver. Interplay effects between beam and organ motion can in those settings lead to under-dosage of the target volume. Dedicated treatment techniques such as gating or abdominal compression are required. In addition 4D treatment planning should be used to determine strategies for patient specific treatment planning such as an increased beam focus or the use of internal target volumes incorporating range changes.Several work packages of the Clinical Research Units 214 and 214/2 funded by the German Research Council investigated the management of organ motion in scanned ion beam therapy. A focus was laid on 4D treatment planning using TRiP4D and the development of motion mitigation strategies including their quality assurance. This review focuses on the activity in the second funding period covering adaptive treatment planning strategies, 4D treatment plan optimization, and the application of motion management in pre-clinical research on radiation therapy of cardiac arrhythmias.
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Affiliation(s)
- Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany.
| | - Klaus Herfarth
- Heidelberg Ion-Beam Therapy Center (HIT) and Department of Radiation Oncology, University Clinic Heidelberg, Heidelberg, Germany
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22
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Mohan R, Das IJ, Ling CC. Empowering Intensity Modulated Proton Therapy Through Physics and Technology: An Overview. Int J Radiat Oncol Biol Phys 2017; 99:304-316. [PMID: 28871980 PMCID: PMC5651132 DOI: 10.1016/j.ijrobp.2017.05.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/11/2017] [Accepted: 05/02/2017] [Indexed: 01/15/2023]
Abstract
Considering the clinical potential of protons attributable to their physical characteristics, interest in proton therapy has increased greatly in this century, as has the number of proton therapy installations. Until recently, passively scattered proton therapy was used almost entirely. Notably, the overall clinical results to date have not shown a convincing benefit of protons over photons. A rapid transition is now occurring with the implementation of the most advanced form of proton therapy, intensity modulated proton therapy (IMPT). IMPT is superior to passively scattered proton therapy and intensity modulated radiation therapy (IMRT) dosimetrically. However, numerous limitations exist in the present IMPT methods. In particular, compared with IMRT, IMPT is highly vulnerable to various uncertainties. In this overview we identify three major areas of current limitations of IMPT: treatment planning, treatment delivery, and motion management, and discuss current and future efforts for improvement. For treatment planning, we need to reduce uncertainties in proton range and in computed dose distributions, improve robust planning and optimization, enhance adaptive treatment planning and delivery, and consider how to exploit the variability in the relative biological effectiveness of protons for clinical benefit. The quality of proton therapy also depends on the characteristics of the IMPT delivery systems and image guidance. Efforts are needed to optimize the beamlet spot size for both improved dose conformality and faster delivery. For the latter, faster energy switching time and increased dose rate are also needed. Real-time in-room volumetric imaging for guiding IMPT is in its early stages with cone beam computed tomography (CT) and CT-on-rails, and continued improvements are anticipated. In addition, imaging of the proton beams themselves, using, for instance, prompt γ emissions, is being developed to determine the proton range and to reduce range uncertainty. With the realization of the advances described above, we posit that IMPT, thus empowered, will lead to substantially improved clinical results.
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Affiliation(s)
- Radhe Mohan
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, Texas.
| | - Indra J Das
- Department of Radiation Oncology, New York University Langone Medical Center, New York, New York
| | - Clifton C Ling
- Varian Medical Systems and Department of Radiation Oncology, Stanford University, Stanford, California
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Bernatowicz K, Zhang Y, Perrin R, Weber DC, Lomax AJ. Advanced treatment planning using direct 4D optimisation for pencil-beam scanned particle therapy. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1361-6560/aa7ab8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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24
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Graeff C. Robustness of 4D-optimized scanned carbon ion beam therapy against interfractional changes in lung cancer. Radiother Oncol 2017; 122:387-392. [PMID: 28073579 DOI: 10.1016/j.radonc.2016.12.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/16/2016] [Accepted: 12/02/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Moving targets could be conformally treated with actively scanned carbon ion beams using 4D-optimization. As this heavily exploits 4D-CTs, an important question is whether the conformity also upholds in the context of interfractional changes, i.e. variable positioning, anatomy and breathing patterns. MATERIALS AND METHODS In 4 lung cancer patients, 6 weekly 4D-CTs were available. 4D-CTs and their phases were non-rigidly registered to propagate contours and 4D-doses. On the first 4D-CT, a 4D-optimized plan delivering a uniform dose to each motion phase (total dose 9.4Gy(RBE)) was simulated, as well as an ITV plan for comparison. On the five following 4D-CTs, 4D-dose was forward calculated and evaluated for target coverage and conformity. Variable uniform (3-7mm) and range margins (2mm/%) were investigated. RESULTS For all patients, target coverage (V95>95% accumulated over 5 fractions) could be achieved, but with variable margin size weakly depending on motion amplitude and range changes. The same margins were also necessary for ITV plans, which lead to lower conformity and higher integral doses. CONCLUSION 4D-optimization appears feasible also under interfractional changes and maintains a dosimetric advantage over less conformal ITV irradiations. Further studies are needed to identify patients benefiting most from the technically more complex 4D-optimization.
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Affiliation(s)
- Christian Graeff
- GSI Helmholzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
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Kubiak T. Particle therapy of moving targets-the strategies for tumour motion monitoring and moving targets irradiation. Br J Radiol 2016; 89:20150275. [PMID: 27376637 DOI: 10.1259/bjr.20150275] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Particle therapy of moving targets is still a great challenge. The motion of organs situated in the thorax and abdomen strongly affects the precision of proton and carbon ion radiotherapy. The motion is responsible for not only the dislocation of the tumour but also the alterations in the internal density along the beam path, which influence the range of particle beams. Furthermore, in case of pencil beam scanning, there is an interference between the target movement and dynamic beam delivery. This review presents the strategies for tumour motion monitoring and moving target irradiation in the context of hadron therapy. Methods enabling the direct determination of tumour position (fluoroscopic imaging of implanted radio-opaque fiducial markers, electromagnetic detection of inserted transponders and ultrasonic tumour localization systems) are presented. Attention is also drawn to the techniques which use external surrogate motion for an indirect estimation of target displacement during irradiation. The role of respiratory-correlated CT [four-dimensional CT (4DCT)] in the determination of motion pattern prior to the particle treatment is also considered. An essential part of the article is the review of the main approaches to moving target irradiation in hadron therapy: gating, rescanning (repainting), gated rescanning and tumour tracking. The advantages, drawbacks and development trends of these methods are discussed. The new accelerators, called "cyclinacs", are presented, because their application to particle therapy will allow making a breakthrough in the 4D spot scanning treatment of moving organs.
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Affiliation(s)
- Tomasz Kubiak
- Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland
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26
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Bernatowicz K, Peroni M, Perrin R, Weber DC, Lomax A. Four-Dimensional Dose Reconstruction for Scanned Proton Therapy Using Liver 4DCT-MRI. Int J Radiat Oncol Biol Phys 2016; 95:216-223. [DOI: 10.1016/j.ijrobp.2016.02.050] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 02/09/2016] [Accepted: 02/17/2016] [Indexed: 01/01/2023]
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27
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Morel P, Flynn RT, Gelover E, Blin G, Vialette S, Wu X, Wang D. MSPT: an open-source motion simulator for proton therapy. Biomed Phys Eng Express 2015. [DOI: 10.1088/2057-1976/1/3/037001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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28
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Chao M, Yuan Y, Sheu RD, Wang K, Rosenzweig KE, Lo YC. A Feasibility Study of Tumor Motion Estimate With Regional Deformable Registration Method for 4-Dimensional Radiation Therapy of Lung Cancer. Technol Cancer Res Treat 2015; 15:NP8-NP16. [PMID: 26294654 DOI: 10.1177/1533034615600569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 07/22/2015] [Indexed: 11/15/2022] Open
Abstract
This study aims to employ 4-dimensional computed tomography to quantify intrafractional tumor motion for patients with lung cancer to improve target localization in radiation therapy. A multistage regional deformable registration was implemented to calculate the excursion of gross tumor volume (GTV) during a breathing cycle. GTV was initially delineated on 0% phase of 4-dimensional computed tomography manually, and a subregion with 20 mm margin supplemented to GTV was generated with Eclipse treatment planning system (Varian Medical Systems, Palo Alto, California). The structures, together with the 4-dimensional computed tomography set, were exported into an in-house software, with which a 3-stage B-spline deformable registration was carried out to map the subregion and warp GTV contour to other breathing phases. The center of mass of the GTV was computed using the contours, and the tumor motion was appraised as the excursion of the center of mass between 0% phase and other phases. Application of the algorithm to the 10 patients showed that clinically satisfactory outcomes were achievable with a spatial accuracy around 2 mm for GTV contour propagation between adjacent phases and 3 mm between opposite phases. The tumor excursion was determined in the vast range of 1 mm through 1.6 cm, depending on the tumor location and tumor size. Compared to the traditional whole image-based registration, the regional method was found computationally a factor of 5 more efficient. The proposed technique has demonstrated its capability in extracting thoracic tumor motion and should find its application in 4-dimensional radiation therapy in the future to maximally utilize the available spatial-temporal information.
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Affiliation(s)
- Ming Chao
- Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY, USA
| | - Yading Yuan
- Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY, USA
| | - Ren-Dih Sheu
- Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY, USA
| | - Kelin Wang
- Division of Radiation Oncology, Pennsylvania State Hershey Cancer Institute, Hershey, PA, USA
| | | | - Yeh-Chi Lo
- Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY, USA
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29
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Eley JG, Newhauser WD, Richter D, Lüchtenborg R, Saito N, Bert C. Robustness of target dose coverage to motion uncertainties for scanned carbon ion beam tracking therapy of moving tumors. Phys Med Biol 2015; 60:1717-40. [PMID: 25650520 DOI: 10.1088/0031-9155/60/4/1717] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Beam tracking with scanned carbon ion radiotherapy achieves highly conformal target dose by steering carbon pencil beams to follow moving tumors using real-time magnetic deflection and range modulation. The purpose of this study was to evaluate the robustness of target dose coverage from beam tracking in light of positional uncertainties of moving targets and beams. To accomplish this, we simulated beam tracking for moving targets in both water phantoms and a sample of lung cancer patients using a research treatment planning system. We modeled various deviations from perfect tracking that could arise due to uncertainty in organ motion and limited precision of a scanned ion beam tracking system. We also investigated the effects of interfractional changes in organ motion on target dose coverage by simulating a complete course of treatment using serial (weekly) 4DCTs from six lung cancer patients. For perfect tracking of moving targets, we found that target dose coverage was high ([Formula: see text] was 94.8% for phantoms and 94.3% for lung cancer patients, respectively) but sensitive to changes in the phase of respiration at the start of treatment and to the respiratory period. Phase delays in tracking the moving targets led to large degradation of target dose coverage (up to 22% drop for a 15° delay). Sensitivity to technical uncertainties in beam tracking delivery was minimal for a lung cancer case. However, interfractional changes in anatomy and organ motion led to large decreases in target dose coverage (target coverage dropped approximately 8% due to anatomy and motion changes after 1 week). Our findings provide a better understand of the importance of each of these uncertainties for beam tracking with scanned carbon ion therapy and can be used to inform the design of future scanned ion beam tracking systems.
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Affiliation(s)
- John Gordon Eley
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. The University of Texas Graduate School of Biomedical Sciences at Houston, 6767 Bertner Avenue, Houston, TX 77030, USA. Department of Radiation Oncology, University of Maryland School of Medicine, 22 South Green Street, Baltimore, MD 21201, USA
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Knopf A, Nill S, Yohannes I, Graeff C, Dowdell S, Kurz C, Sonke JJ, Biegun AK, Lang S, McClelland J, Champion B, Fast M, Wölfelschneider J, Gianoli C, Rucinski A, Baroni G, Richter C, van de Water S, Grassberger C, Weber D, Poulsen P, Shimizu S, Bert C. Challenges of radiotherapy: report on the 4D treatment planning workshop 2013. Phys Med 2014; 30:809-15. [PMID: 25172392 DOI: 10.1016/j.ejmp.2014.07.341] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/23/2014] [Accepted: 07/28/2014] [Indexed: 01/27/2023] Open
Abstract
This report, compiled by experts on the treatment of mobile targets with advanced radiotherapy, summarizes the main conclusions and innovations achieved during the 4D treatment planning workshop 2013. This annual workshop focuses on research aiming to advance 4D radiotherapy treatments, including all critical aspects of time resolved delivery, such as in-room imaging, motion detection, motion managing, beam application, and quality assurance techniques. The report aims to revise achievements in the field and to discuss remaining challenges and potential solutions. As main achievements advances in the development of a standardized 4D phantom and in the area of 4D-treatment plan optimization were identified. Furthermore, it was noticed that MR imaging gains importance and high interest for sequential 4DCT/MR data sets was expressed, which represents a general trend of the field towards data covering a longer time period of motion. A new point of attention was work related to dose reconstructions, which may play a major role in verification of 4D treatment deliveries. The experimental validation of results achieved by 4D treatment planning and the systematic evaluation of different deformable image registration methods especially for inter-modality fusions were identified as major remaining challenges. A challenge that was also suggested as focus for future 4D workshops was the adaptation of image guidance approaches from conventional radiotherapy into particle therapy. Besides summarizing the last workshop, the authors also want to point out new evolving demands and give an outlook on the focus of the next workshop.
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Affiliation(s)
| | | | | | | | | | | | | | - Aleksandra K Biegun
- KVI-Center for Advanced Radiation Technology, University of Groningen, Netherlands
| | | | | | | | | | | | - Chiara Gianoli
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy; Department of Radiation Oncology, Heidelberg University Hospital, Germany
| | - Antoni Rucinski
- Radiation Oncology Department, SLK-Klinik Heilbronn, Germany
| | - Guido Baroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano and Bioengineering Unit, CNAO Foundation, Pavia, Italy
| | - Christian Richter
- Oncoray - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital C.G. Carus, TU Dresden, Helmholtz-Zentrum Dresden-Rossendorf, DKTK, Dresden, Germany
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