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Tominaga Y, Suga M, Takeda M, Yamamoto Y, Akagi T, Kato T, Tokumaru S, Yamamoto M, Oita M. Comparing interplay effects in scanned proton therapy of lung cancer: Free breathing with various layer and volume rescanning versus respiratory gating with different gate widths. Phys Med 2024; 120:103323. [PMID: 38461635 DOI: 10.1016/j.ejmp.2024.103323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/07/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024] Open
Abstract
PURPOSE We investigated interplay effects and treatment time (TT) in scanned proton therapy for lung cancer patients. We compared free-breathing (FB) approaches with multiple rescanning strategies and respiratory-gating (RG) methods with various gating widths to identify the superior irradiation technique. METHODS Plans were created with 4/1, 2/2, and 1/4 layered/volume rescans of FB (L4V1, L2V2, and L1V4), and 50%, 30%, and 10% gating widths of the total respiratory curves (G50, G30, and G10) of the RG plans with L4V1. We calculated 4-dimensional dynamic doses assuming a constant sinusoidal curve for six irradiation methods. The reconstructed doses per fraction were compared with planned doses in terms of dose differences in 99% clinical-target-volume (CTV) (ΔD99%), near-maximum dose differences (ΔD2%) at organs-at-risk (OARs), and TT. RESULTS The mean/minimum CTV ΔD99% values for FB were -1.0%/-4.9%, -0.8%/-4.3%, and -0.1%/-1.0% for L4V1, L2V2, and L1V4, respectively. Those for RG were -0.3%/-1.7%, -0.1%/-1.0%, and 0.0%/-0.5% for G50, G30, and G10, respectively. The CTV ΔD99% of the RGs with less than 50% gate width and the FBs of L1V4 were within the desired tolerance (±3.0%), and the OARs ΔD2% for RG were lower than those for FB. The mean TTs were 90, 326, 824, 158, 203, and 422 s for L4V1, L2V2, L1V4, G50, G30, and G10, respectively. CONCLUSIONS FB (L4V1) is the most efficient treatment, but not necessarily the optimal choice due to interplay effects. To satisfy both TT extensions and interplay, RG with a gate width as large as possible within safety limits is desirable.
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Affiliation(s)
- Yuki Tominaga
- Department of Radiotherapy, Medical Co. Hakuhokai, Osaka Proton Therapy Clinic, 27-9 Kasugadenaka, Konohana-ku, Osaka 554-0022, Japan.
| | - Masaki Suga
- Hyogo Ion Beam Medical Center, 1-2-1, Kouto, Shingucho, Tatsuno, Hyogo 679-5165, Japan
| | - Mikuni Takeda
- Hyogo Ion Beam Medical Center, 1-2-1, Kouto, Shingucho, Tatsuno, Hyogo 679-5165, Japan
| | - Yuki Yamamoto
- Hyogo Ion Beam Medical Center, 1-2-1, Kouto, Shingucho, Tatsuno, Hyogo 679-5165, Japan
| | - Takashi Akagi
- Hyogo Ion Beam Medical Support, 1-2-1, Kouto, Shingucho, Tatsuno, Hyogo 679-5165, Japan
| | - Takahiro Kato
- Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan; Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima 172, Yatsuyamada 7 Chome, Koriyama, Fukushima 963-8052, Japan
| | - Sunao Tokumaru
- Hyogo Ion Beam Medical Center, 1-2-1, Kouto, Shingucho, Tatsuno, Hyogo 679-5165, Japan
| | - Michinori Yamamoto
- Department of Radiotherapy, Medical Co. Hakuhokai, Osaka Proton Therapy Clinic, 27-9 Kasugadenaka, Konohana-ku, Osaka 554-0022, Japan
| | - Masataka Oita
- Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 5-1 Shikata-cho, 2-chome, Kita-ku, Okayama 700-8558, Japan
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Takagi M, Hasegawa Y, Tateoka K, Takada Y, Hareyama M. Dosimetric Comparison Study of Proton Therapy Using Line Scanning versus Passive Scattering and Volumetric Modulated Arc Therapy for Localized Prostate Cancer. Cancers (Basel) 2024; 16:403. [PMID: 38254892 PMCID: PMC10814771 DOI: 10.3390/cancers16020403] [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: 12/13/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND The proton irradiation modality has transitioned from passive scattering (PS) to pencil beam scanning. Nevertheless, the documented outcomes predominantly rely on PS. METHODS Thirty patients diagnosed with prostate cancer were selected to assess treatment planning across line scanning (LS), PS, and volumetric modulated arc therapy (VMAT). Dose constraints encompassed clinical target volume (CTV) D98 ≥ 73.0 Gy (RBE), rectal wall V65 < 17% and V40 < 35%, and bladder wall V65 < 25% and V40 < 50%. The CTV, rectal wall, and bladder wall dose volumes were calculated and evaluated using the Freidman test. RESULTS The LS technique adhered to all dose limitations. For the rectal and bladder walls, 10 (33.3%) and 21 (70.0%) patients in the PS method and 5 (16.7%) and 1 (3.3%) patients in VMAT, respectively, failed to meet the stipulated requirements. The wide ranges of the rectal and bladder wall volumes (V10-70) were lower with LS than with PS and VMAT. LS outperformed VMAT across all dose-volume rectal and bladder wall indices. CONCLUSION The LS method demonstrated a reduction in rectal and bladder doses relative to PS and VMAT, thereby suggesting the potential for mitigating toxicities.
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Affiliation(s)
- Masaru Takagi
- Department of Radiation Oncology, Sapporo Teishinkai Hospital, Sapporo 065-0033, Japan
| | - Yasuhiro Hasegawa
- Department of Radiation Physics, Sapporo Teishinkai Hospital, Sapporo 065-0033, Japan
| | - Kunihiko Tateoka
- Department of Radiation Physics, Sapporo Teishinkai Hospital, Sapporo 065-0033, Japan
| | - Yu Takada
- Department of Radiation Oncology, Sapporo Teishinkai Hospital, Sapporo 065-0033, Japan
| | - Masato Hareyama
- Department of Radiation Oncology, Sapporo Teishinkai Hospital, Sapporo 065-0033, Japan
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Jeon C, Lee J, Shin J, Cheon W, Ahn S, Jo K, Han Y. Monte Carlo simulation-based patient-specific QA using machine log files for line-scanning proton radiation therapy. Med Phys 2023; 50:7139-7153. [PMID: 37756652 DOI: 10.1002/mp.16747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Quality assurance (QA) is a prerequisite for safe and accurate pencil-beam proton therapy. Conventional measurement-based patient-specific QA (pQA) can only verify limited aspects of patient treatment and is labor-intensive. Thus, a better method is needed to ensure the integrity of the treatment plan. PURPOSE Line scanning, which involves continuous and rapid delivery of pencil beams, is a state-of-the-art proton therapy technique. Machine performance in delivering scanning protons is dependent on the complexity of the beam modulations. Moreover, it contributes to patient treatment accuracy. A Monte Carlo (MC) simulation-based QA method that reflects the uncertainty related to the machine during scanning beam delivery was developed and verified for clinical applications to pQA. METHODS Herein, a tool for particle simulation (TOPAS) for nozzle modeling was used, and the code was commissioned against the measurements. To acquire the beam delivery uncertainty for each plan, patient plans were delivered. Furthermore, log files recorded every 60 μs by the monitors downstream of the nozzle were exported from the treatment control system. The spot positions and monitor unit (MU) counts in the log files were converted to dipole magnet strengths and number of particles, respectively, and entered into the TOPAS. For the 68 clinical cases, MC simulations were performed in a solid water phantom, and two-dimensional (2D) absolute dose distributions at 20-mm depth were measured using an ionization chamber array (Octavius 1500, PTW, Freiburg, Germany). Consequently, the MC-simulated 2D dose distributions were compared with the measured data, and the dose distributions in the pre-treatment QA plan created with RayStation (RaySearch Laboratories, Stockholm, Sweden). Absolute dose comparisons were made using gamma analysis with 3%/3 mm and 2%/2 mm criteria for 47 clinical cases without considering daily machine output variation in the MC simulation and 21 cases with daily output variation, respectively. All cases were analyzed with 90% or 95% of passing rate thresholds. RESULTS For 47 clinical cases not considering daily output variations, the absolute gamma passing rates compared with the pre-treatment QA plan were 99.71% and 96.97%, and the standard deviations (SD) were 0.70% and 3.78% with the 3%/3 mm or 2%/2 mm criteria, respectively. Compared with the measurements, the passing rate of 2%/2 mm gamma criterion was 96.76% with 3.99% of SD. For the 21 clinical cases compared with pre-treatment QA plan data and measurements considering daily output variations, the 2%/2 mm absolute gamma analysis result was 98.52% with 1.43% of SD and 97.67% with 2.72% of SD, respectively. With a 95% passing rate threshold of 2%/2 mm criterion, the false-positive and false-negative were 21.8% and 8.3% for without and with considering output variation, respectively. With a 90% threshold, the false-positive and false-negative reduced to 11.4% and 0% for without and with considering output variation, respectively. CONCLUSIONS A log-file-based MC simulation method for patient QA of line-scanning proton therapy was successfully developed. The proposed method exhibited clinically acceptable accuracy, thereby exhibiting a potential to replace the measurement-based dosimetry QA method with a 90% gamma passing rate threshold when applying the 2%/2 mm criterion.
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Affiliation(s)
- Chanil Jeon
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jinhyeop Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jungwook Shin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Rockville, Maryland, USA
| | - Wonjoong Cheon
- Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sunghwan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea
| | - Kwanghyun Jo
- Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea
| | - Youngyih Han
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea
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Li H, Dong L, Bert C, Chang J, Flampouri S, Jee KW, Lin L, Moyers M, Mori S, Rottmann J, Tryggestad E, Vedam S. Report of AAPM Task Group 290: Respiratory motion management for particle therapy. Med Phys 2022; 49:e50-e81. [PMID: 35066871 PMCID: PMC9306777 DOI: 10.1002/mp.15470] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 12/28/2021] [Accepted: 01/05/2022] [Indexed: 11/16/2022] Open
Abstract
Dose uncertainty induced by respiratory motion remains a major concern for treating thoracic and abdominal lesions using particle beams. This Task Group report reviews the impact of tumor motion and dosimetric considerations in particle radiotherapy, current motion‐management techniques, and limitations for different particle‐beam delivery modes (i.e., passive scattering, uniform scanning, and pencil‐beam scanning). Furthermore, the report provides guidance and risk analysis for quality assurance of the motion‐management procedures to ensure consistency and accuracy, and discusses future development and emerging motion‐management strategies. This report supplements previously published AAPM report TG76, and considers aspects of motion management that are crucial to the accurate and safe delivery of particle‐beam therapy. To that end, this report produces general recommendations for commissioning and facility‐specific dosimetric characterization, motion assessment, treatment planning, active and passive motion‐management techniques, image guidance and related decision‐making, monitoring throughout therapy, and recommendations for vendors. Key among these recommendations are that: (1) facilities should perform thorough planning studies (using retrospective data) and develop standard operating procedures that address all aspects of therapy for any treatment site involving respiratory motion; (2) a risk‐based methodology should be adopted for quality management and ongoing process improvement.
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Affiliation(s)
- Heng Li
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Christoph Bert
- Department of Radiation Oncology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Joe Chang
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Stella Flampouri
- Department of Radiation Oncology, Emory University, Atlanta, GA, USA
| | - Kyung-Wook Jee
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, USA
| | - Liyong Lin
- Department of Radiation Oncology, Emory University, Atlanta, GA, USA
| | - Michael Moyers
- Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai, China
| | - Shinichiro Mori
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
| | - Joerg Rottmann
- Center for Proton Therapy, Proton Therapy Singapore, Proton Therapy Pte Ltd, Singapore
| | - Erik Tryggestad
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Sastry Vedam
- Department of Radiation Oncology, University of Maryland, Baltimore, USA
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Nesteruk KP, Bolsi A, Lomax AJ, Meer D, van de Water S, Schippers JM. A static beam delivery device for fast scanning proton arc-therapy. Phys Med Biol 2021; 66:055018. [PMID: 33498040 DOI: 10.1088/1361-6560/abe02b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Arc-therapy is a dose delivery technique regularly applied in photon radiation therapy, and is currently subject of great interest for proton therapy as well. In this technique, proton beams are aimed at a tumor from different continuous ranges of incident directions (so called 'arcs'). This technique can potentially yield a better dose conformity around the tumor and a very low dose in the surrounding healthy tissue. Currently, proton-arc therapy is performed by rotating a proton gantry around the patient, adapting the normally used dose-delivery method to the arc-specific motion of the gantry. Here we present first results from a feasibility study of the conceptual design of a new static fast beam delivery device/system for proton-arc therapy, which could be used instead of a gantry. In this novel concept, the incident angle of proton beams can be set rapidly by only changing field strengths of small magnets. This device eliminates the motion of the heavy gantry and related hardware. Therefore, a reduction of the total treatment time is expected. In the feasibility study presented here, we concentrate on the concept of the beam transport. Based on several simple, but realistic assumptions and approximations, proton tracking calculations were performed in a 3D magnetic field map, to calculate the beam transport in this device and to investigate and address several beam-optics challenges. We propose and simulate corresponding solutions and discuss their outcomes. To enable the implementation of some usually applied techniques in proton therapy, such as pencil beam scanning, energy modulation and beam shaping, we present and discuss our proposals. Here we present the concept of a new idea to perform fast proton arc-scanning and we report on first results of a feasibility study. Based on these results, we propose several options and next steps in the design.
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Affiliation(s)
- K P Nesteruk
- Paul Scherrer Institute, Villigen PSI, Switzerland
| | - A Bolsi
- Paul Scherrer Institute, Villigen PSI, Switzerland
| | - A J Lomax
- Paul Scherrer Institute, Villigen PSI, Switzerland.,Department of Physics, ETH Zurich, Switzerland
| | - D Meer
- Paul Scherrer Institute, Villigen PSI, Switzerland
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Han Y. Current status of proton therapy techniques for lung cancer. Radiat Oncol J 2019; 37:232-248. [PMID: 31918460 PMCID: PMC6952710 DOI: 10.3857/roj.2019.00633] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 12/26/2019] [Indexed: 12/11/2022] Open
Abstract
Proton beams have been used for cancer treatment for more than 28 years, and several technological advancements have been made to achieve improved clinical outcomes by delivering more accurate and conformal doses to the target cancer cells while minimizing the dose to normal tissues. The state-of-the-art intensity modulated proton therapy is now prevailing as a major treatment technique in proton facilities worldwide, but still faces many challenges in being applied to the lung. Thus, in this article, the current status of proton therapy technique is reviewed and issues regarding the relevant uncertainty in proton therapy in the lung are summarized.
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Affiliation(s)
- Youngyih Han
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
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7
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The dosimetric effect of residual breath-hold motion in pencil beam scanned proton therapy – An experimental study. Radiother Oncol 2019; 134:135-142. [DOI: 10.1016/j.radonc.2019.01.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/25/2019] [Accepted: 01/27/2019] [Indexed: 12/25/2022]
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Psoroulas S, Bula C, Actis O, Weber DC, Meer D. A predictive algorithm for spot position corrections after fast energy switching in proton pencil beam scanning. Med Phys 2018; 45:4806-4815. [DOI: 10.1002/mp.13217] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 08/21/2018] [Accepted: 09/19/2018] [Indexed: 11/09/2022] Open
Affiliation(s)
- Serena Psoroulas
- Centre for Proton Therapy Paul Scherrer Institut CH‐5232Villigen PSI Switzerland
| | - Christian Bula
- Centre for Proton Therapy Paul Scherrer Institut CH‐5232Villigen PSI Switzerland
| | - Oxana Actis
- Centre for Proton Therapy Paul Scherrer Institut CH‐5232Villigen PSI Switzerland
| | - Damien Charles Weber
- Centre for Proton Therapy Paul Scherrer Institut CH‐5232Villigen PSI Switzerland
| | - David Meer
- Centre for Proton Therapy Paul Scherrer Institut CH‐5232Villigen PSI Switzerland
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Trnková P, Knäusl B, Actis O, Bert C, Biegun AK, Boehlen TT, Furtado H, McClelland J, Mori S, Rinaldi I, Rucinski A, Knopf AC. Clinical implementations of 4D pencil beam scanned particle therapy: Report on the 4D treatment planning workshop 2016 and 2017. Phys Med 2018; 54:121-130. [PMID: 30337001 DOI: 10.1016/j.ejmp.2018.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/18/2018] [Accepted: 10/02/2018] [Indexed: 12/14/2022] Open
Abstract
In 2016 and 2017, the 8th and 9th 4D treatment planning workshop took place in Groningen (the Netherlands) and Vienna (Austria), respectively. This annual workshop brings together international experts to discuss research, advances in clinical implementation as well as problems and challenges in 4D treatment planning, mainly in spot scanned proton therapy. In the last two years several aspects like treatment planning, beam delivery, Monte Carlo simulations, motion modeling and monitoring, QA phantoms as well as 4D imaging were thoroughly discussed. This report provides an overview of discussed topics, recent findings and literature review from the last two years. Its main focus is to highlight translation of 4D research into clinical practice and to discuss remaining challenges and pitfalls that still need to be addressed and to be overcome.
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Affiliation(s)
- Petra Trnková
- HollandPTC, P.O. Box 5046, 2600 GA Delft, the Netherlands; Erasmus MC, P.O. Box 5201, 3008 AE Rotterdam, the Netherlands
| | - Barbara Knäusl
- Department of Radiation Oncology, Division of Medical Radiation Physics, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/AKH Vienna, Austria
| | - Oxana Actis
- Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Aleksandra K Biegun
- KVI-Center for Advanced Radiation Technology, University of Groningen, Groningen, the Netherlands
| | - Till T Boehlen
- Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - Hugo Furtado
- Department of Radiation Oncology, Division of Medical Radiation Physics, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/AKH Vienna, Austria
| | - Jamie McClelland
- Centre for Medical Image Computing, Dept. Medical Physics and Biomedical, University College London, London, UK
| | - Shinichiro Mori
- National Institute of Radiological Sciences for Charged Particle Therapy, Chiba, Japan
| | - Ilaria Rinaldi
- Lyon 1 University and CNRS/IN2P3, UMR 5822, 69622 Villeurbanne, France; MAASTRO Clinic, P.O. Box 3035, 6202 NA Maastricht, the Netherlands
| | | | - Antje C Knopf
- University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, Groningen, the Netherlands.
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Jensen MF, Hoffmann L, Petersen JBB, Møller DS, Alber M. Energy layer optimization strategies for intensity-modulated proton therapy of lung cancer patients. Med Phys 2018; 45:4355-4363. [PMID: 30129041 DOI: 10.1002/mp.13139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 08/06/2018] [Accepted: 08/13/2018] [Indexed: 11/07/2022] Open
Abstract
PURPOSE When treating lung cancer patients with intensity-modulated proton therapy (IMPT), target coverage can only be guaranteed when utilizing motion mitigation. The three motion mitigation techniques, gating, breath-hold, and dose repainting, all benefit from a more rapid application of the treatment plan. A lower limit for the ungated treatment time is defined by the number of energy layers in the IMPT plan. By limiting this number during treatment planning, IMPT could become more viable for lung cancer patients. We investigate to what extend the number of layers can be reduced in single-field optimization (SFO) and multifield optimization (MFO) plans and which implications it has on the plan quality and robustness. METHODS We have implemented three distinct layer-reducing strategies in the treatment planning system Hyperion; constant energy steps, exponential energy steps, and an adaptive strategy, where the spot weights are exposed to a group sparsity penalty in combination with layer exclusion during optimization. Four levels of increasing layer removal are planned for each strategy. SFO and MFO plans with three treatment fields are created for eleven locally advanced NSCLC patients on the midventilation 4DCT phase to simulate a breath-hold. A minimum dose to the target is ensured for each degree of layer reduction, reflecting the plan quality in the homogeneity index (HI). Plan quality was also assessed by a robustness evaluation, where the patient setup was shifted 2 mm or 4 mm in six directions. RESULTS The three strategies result in very similar target coverages and robustness levels as a function of removed layers. The HI increases unacceptably for all the SFO plans after 50% layer removal as compared to the reference plan, while all the MFO plans are clinically acceptable with up to a highest removed percentage of 75%. The robustness level is constant as a function of removed layers. The SFO plans are significantly more robust than the MFO plans with all P-values below 0.001 (Wilcoxon signed-rank). The overall mean D98% CTV dose difference is at 2-mm setup error amplitude: 0.7 Gy (SFO) and 1.9 Gy (MFO), and at 4 mm: 3.2 Gy (SFO) and 5.4 Gy (MFO), respectively. CONCLUSIONS The number of layers in MFO plans can be reduced substantially more than in SFO plans without compromising plan quality. Furthermore, as the robustness is independent of the number of layers, it follows that if the level of robustness is acceptable or enforced via robust optimization, MFO plans could be candidates for treatment time reductions via energy layer reductions.
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Affiliation(s)
- M Fuglsang Jensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, 8200, Aarhus N, Denmark.,Department of Oncology, Aarhus University Hospital, 8200, Aarhus N, Denmark
| | - L Hoffmann
- Department of Oncology, Aarhus University Hospital, 8200, Aarhus N, Denmark
| | - J B B Petersen
- Department of Oncology, Aarhus University Hospital, 8200, Aarhus N, Denmark
| | - D S Møller
- Department of Oncology, Aarhus University Hospital, 8200, Aarhus N, Denmark
| | - M Alber
- Department of Radiation Oncology, Heidelberg University Hospital, 69120, Heidelberg, Germany
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Klimpki G, Zhang Y, Fattori G, Psoroulas S, Weber DC, Lomax A, Meer D. The impact of pencil beam scanning techniques on the effectiveness and efficiency of rescanning moving targets. ACTA ACUST UNITED AC 2018; 63:145006. [DOI: 10.1088/1361-6560/aacd27] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Gorgisyan J, Munck af Rosenschold P, Perrin R, Persson GF, Josipovic M, Belosi MF, Engelholm SA, Weber DC, Lomax AJ. Feasibility of Pencil Beam Scanned Intensity Modulated Proton Therapy in Breath-hold for Locally Advanced Non-Small Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2017; 99:1121-1128. [DOI: 10.1016/j.ijrobp.2017.08.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/13/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022]
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13
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Klimpki G, Psoroulas S, Bula C, Rechsteiner U, Eichin M, Weber DC, Lomax A, Meer D. A beam monitoring and validation system for continuous line scanning in proton therapy. ACTA ACUST UNITED AC 2017; 62:6126-6143. [DOI: 10.1088/1361-6560/aa772e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Perrin RL, Zakova M, Peroni M, Bernatowicz K, Bikis C, Knopf AK, Safai S, Fernandez-Carmona P, Tscharner N, Weber DC, Parkel TC, Lomax AJ. An anthropomorphic breathing phantom of the thorax for testing new motion mitigation techniques for pencil beam scanning proton therapy. Phys Med Biol 2017; 62:2486-2504. [DOI: 10.1088/1361-6560/62/6/2486] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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15
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Required transition from research to clinical application: Report on the 4D treatment planning workshops 2014 and 2015. Phys Med 2016; 32:874-82. [DOI: 10.1016/j.ejmp.2016.05.064] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 05/28/2016] [Accepted: 05/31/2016] [Indexed: 12/25/2022] Open
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Deep Inspiration Breath Hold-Based Radiation Therapy: A Clinical Review. Int J Radiat Oncol Biol Phys 2015; 94:478-92. [PMID: 26867877 DOI: 10.1016/j.ijrobp.2015.11.049] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 11/03/2015] [Accepted: 11/29/2015] [Indexed: 01/06/2023]
Abstract
Several recent developments in linear accelerator-based radiation therapy (RT) such as fast multileaf collimators, accelerated intensity modulation paradigms like volumeric modulated arc therapy and flattening filter-free (FFF) high-dose-rate therapy have dramatically shortened the duration of treatment fractions. Deliverable photon dose distributions have approached physical complexity limits as a consequence of precise dose calculation algorithms and online 3-dimensional image guided patient positioning (image guided RT). Simultaneously, beam quality and treatment speed have continuously been improved in particle beam therapy, especially for scanned particle beams. Applying complex treatment plans with steep dose gradients requires strategies to mitigate and compensate for motion effects in general, particularly breathing motion. Intrafractional breathing-related motion results in uncertainties in dose delivery and thus in target coverage. As a consequence, generous margins have been used, which, in turn, increases exposure to organs at risk. Particle therapy, particularly with scanned beams, poses additional problems such as interplay effects and range uncertainties. Among advanced strategies to compensate breathing motion such as beam gating and tracking, deep inspiration breath hold (DIBH) gating is particularly advantageous in several respects, not only for hypofractionated, high single-dose stereotactic body RT of lung, liver, and upper abdominal lesions but also for normofractionated treatment of thoracic tumors such as lung cancer, mediastinal lymphomas, and breast cancer. This review provides an in-depth discussion of the rationale and technical implementation of DIBH gating for hypofractionated and normofractionated RT of intrathoracic and upper abdominal tumors in photon and proton RT.
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