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Liang X, Liu C, Shen J, Flampouri S, Park JC, Lu B, Yaddanapudi S, Tan J, Furutani KM, Beltran CJ. Impact of proton PBS machine operating parameters on the effectiveness of layer rescanning for interplay effect mitigation in lung SBRT treatment. J Appl Clin Med Phys 2024:e14342. [PMID: 38590112 DOI: 10.1002/acm2.14342] [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: 12/22/2023] [Revised: 02/07/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Rescanning is a common technique used in proton pencil beam scanning to mitigate the interplay effect. Advances in machine operating parameters across different generations of particle therapy systems have led to improvements in beam delivery time (BDT). However, the potential impact of these improvements on the effectiveness of rescanning remains an underexplored area in the existing research. METHODS We systematically investigated the impact of proton machine operating parameters on the effectiveness of layer rescanning in mitigating interplay effect during lung SBRT treatment, using the CIRS phantom. Focused on the Hitachi synchrotron particle therapy system, we explored machine operating parameters from our institution's current (2015) and upcoming systems (2025A and 2025B). Accumulated dynamic 4D dose were reconstructed to assess the interplay effect and layer rescanning effectiveness. RESULTS Achieving target coverage and dose homogeneity within 2% deviation required 6, 6, and 20 times layer rescanning for the 2015, 2025A, and 2025B machine parameters, respectively. Beyond this point, further increasing the number of layer rescanning did not further improve the dose distribution. BDTs without rescanning were 50.4, 24.4, and 11.4 s for 2015, 2025A, and 2025B, respectively. However, after incorporating proper number of layer rescanning (six for 2015 and 2025A, 20 for 2025B), BDTs increased to 67.0, 39.6, and 42.3 s for 2015, 2025A, and 2025B machine parameters. Our data also demonstrated the potential problem of false negative and false positive if the randomness of the respiratory phase at which the beam is initiated is not considered in the evaluation of interplay effect. CONCLUSION The effectiveness of layer rescanning for mitigating interplay effect is affected by machine operating parameters. Therefore, past clinical experiences may not be applicable to modern machines.
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Affiliation(s)
- Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
| | - Chunbo Liu
- Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA
| | - Stella Flampouri
- Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, USA
| | - Justin C Park
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
| | - Bo Lu
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Jun Tan
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
| | - Keith M Furutani
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
| | - Chris J Beltran
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, USA
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Tsubouchi T, Beltran CJ, Yagi M, Hamatani N, Takashina M, Shimizu S, Kanai T, Furutani KM. Beam delivery characteristics of the Hitachi carbon ion scanning system at Osaka Heavy Ion Medical Accelerator in Kansai (HIMAK). Med Phys 2024; 51:2239-2250. [PMID: 37877590 DOI: 10.1002/mp.16791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/15/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Using the pencil beam raster scanning method employed at most carbon beam treatment facilities, spots can be moved without interrupting the beam, allowing for the delivery of a dose between spots (move dose). This technique is also known as Dose-Driven-Continuous-Scanning (DDCS). To minimize its impact on HIMAK patient dosimetry, there's an upper limit to the move dose. Spots within a layer are grouped into sets, or "break points," allowing continuous irradiation. The beam is turned off when transitioning between sets or at the end of a treatment layer or spill. The control system beam-off is accomplished by turning off the RF Knockout (RFKO) extraction and after a brief delay the High Speed Steering Magnet (HSST) redirects the beam transport away from isocenter to a beam dump. PURPOSE The influence of the move dose and beam on/off control on the dose distribution and irradiation time was evaluated by measurements never before reported and modelled for Hitachi Carbon DDCS. METHOD We conducted fixed-point and scanning irradiation experiments at three different energies, both with and without breakpoints. For fixed-point irradiation, we utilized a 2D array detector and an oscilloscope to measure beam intensity over time. The oscilloscope data enabled us to confirm beam-off and beam-on timing due to breakpoints, as well as the relative timing of the RFKO signal, HSST signal, and dose monitor (DM) signals. From these measurements, we analyzed and modelled the temporal characteristics of the beam intensity. We also developed a model for the spot shape and amplitude at isocenter occurring after the beam-off signal which we called flap dose and its dependence on beam intensity. In the case of scanning irradiation, we measured move doses using the 2D array detector and compared these measurements with our model. RESULT We observed that the most dominant time variation of the beam intensity was at 1 kHz and its harmonic frequencies. Our findings revealed that the derived beam intensity cannot reach the preset beam intensity when each spot belongs to different breakpoints. The beam-off time due to breakpoints was approximately 100 ms, while the beam rise time and fall time (tdecay ) were remarkably fast, about 10 ms and 0.2 ms, respectively. Moreover, we measured the time lag (tdelay ) of approximately 0.2 ms between the RFKO and HSST signals. Since tdelay ≈ tdecay at HIMAK then the HSST is activated after the residual beam intensity, resulting in essentially zero flap dose at isocenter from the HSST. Our measurements of the move dose demonstrated excellent agreement with the modelled move dose. CONCLUSION We conducted the first move dose measurement for a Hitachi Carbon synchrotron, and our findings, considering beam on/off control details, indicate that Hitachi's carbon synchrotron provides a stable beam at HIMAK. Our work suggests that measuring both move dose and flap dose should be part of the commissioning process and possibly using our model in the Treatment Planning System (TPS) for new facilities with treatment delivery control systems with higher beam intensities and faster beam-off control.
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Affiliation(s)
- Toshiro Tsubouchi
- Department of Medical Physics, Osaka Heavy Ion Therapy Center, Osaka, Japan
| | - Chris J Beltran
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
- Department of Radiation Oncology, Division of Medical Physics, Mayo Clinic, Jacksonville, Florida, USA
| | - Masashi Yagi
- Department of Medical Physics, Osaka Heavy Ion Therapy Center, Osaka, Japan
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Noriaki Hamatani
- Department of Medical Physics, Osaka Heavy Ion Therapy Center, Osaka, Japan
| | - Masaaki Takashina
- Department of Medical Physics, Osaka Heavy Ion Therapy Center, Osaka, Japan
| | - Shinichi Shimizu
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tatsuaki Kanai
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Keith M Furutani
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Osaka, Japan
- Department of Radiation Oncology, Division of Medical Physics, Mayo Clinic, Jacksonville, Florida, USA
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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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Monaco V, Ali OH, Bersani D, Abujami M, Boscardin M, Cartiglia N, Betta GFD, Data E, Donetti M, Ferrero M, Ficorella F, Giordanengo S, Villarreal OAM, Milian FM, Mohammadian-Behbahani MR, Olivares DM, Pullia M, Tommasino F, Verroi E, Vignati A, Cirio R, Sacchi R. Performance of LGAD strip detectors for particle counting of therapeutic proton beams. Phys Med Biol 2023; 68:235009. [PMID: 37827167 DOI: 10.1088/1361-6560/ad02d5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 10/12/2023] [Indexed: 10/14/2023]
Abstract
Objective. The performance of silicon detectors with moderate internal gain, named low-gain avalanche diodes (LGADs), was studied to investigate their capability to discriminate and count single beam particles at high fluxes, in view of future applications for beam characterization and on-line beam monitoring in proton therapy.Approach. Dedicated LGAD detectors with an active thickness of 55μm and segmented in 2 mm2strips were characterized at two Italian proton-therapy facilities, CNAO in Pavia and the Proton Therapy Center of Trento, with proton beams provided by a synchrotron and a cyclotron, respectively. Signals from single beam particles were discriminated against a threshold and counted. The number of proton pulses for fixed energies and different particle fluxes was compared with the charge collected by a compact ionization chamber, to infer the input particle rates.Main results. The counting inefficiency due to the overlap of nearby signals was less than 1% up to particle rates in one strip of 1 MHz, corresponding to a mean fluence rate on the strip of about 5 × 107p/(cm2·s). Count-loss correction algorithms based on the logic combination of signals from two neighboring strips allow to extend the maximum counting rate by one order of magnitude. The same algorithms give additional information on the fine time structure of the beam.Significance. The direct counting of the number of beam protons with segmented silicon detectors allows to overcome some limitations of gas detectors typically employed for beam characterization and beam monitoring in particle therapy, providing faster response times, higher sensitivity, and independence of the counts from the particle energy.
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Affiliation(s)
- Vincenzo Monaco
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Omar Hammad Ali
- Fondazione Bruno Kessler, Center for Sensors & Devices , Trento, Italy
| | - Davide Bersani
- Istituto Nazionale di Fisica Nucleare, sezione di Pisa, Italy
| | - Mohammed Abujami
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Maurizio Boscardin
- Fondazione Bruno Kessler, Center for Sensors & Devices , Trento, Italy
- Trento Institute for Fundamental Physics and Applications, Povo, Trento, Italy
| | | | - Gian Franco Dalla Betta
- Trento Institute for Fundamental Physics and Applications, Povo, Trento, Italy
- Università degli Studi di Trento, Trento, Italy
| | - Emanuele Data
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Marco Donetti
- CNAO, Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Marco Ferrero
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | | | | | | | - Felix Mas Milian
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
- Universidade Estadual de Santa Cruz, Department of Exact and Technological Sciences, Ilhéus, Brazil
| | | | - Diango Montalvan Olivares
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Marco Pullia
- CNAO, Centro Nazionale di Adroterapia Oncologica, Pavia, Italy
| | - Francesco Tommasino
- Trento Institute for Fundamental Physics and Applications, Povo, Trento, Italy
- Università degli Studi di Trento, Trento, Italy
| | - Enrico Verroi
- Trento Institute for Fundamental Physics and Applications, Povo, Trento, Italy
| | - Anna Vignati
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Roberto Cirio
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
| | - Roberto Sacchi
- Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino, Italy
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Italy
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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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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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Zhu M, Flampouri S, Stanforth A, Slopsema R, Diamond Z, LePain W, Langen K. Effect of the initial energy layer and spot placement parameters on IMPT delivery efficiency and plan quality. J Appl Clin Med Phys 2023; 24:e13997. [PMID: 37101399 PMCID: PMC10476974 DOI: 10.1002/acm2.13997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 03/14/2023] [Accepted: 04/05/2023] [Indexed: 04/28/2023] Open
Abstract
PURPOSE Improving efficiency of intensity modulated proton therapy (IMPT) treatment can be achieved by shortening the beam delivery time. The purpose of this study is to reduce the delivery time of IMPT, while maintaining the plan quality, by finding the optimal initial proton spot placement parameters. METHODS Seven patients previously treated in the thorax and abdomen with gated IMPT and voluntary breath-hold were included. In the clinical plans, the energy layer spacing (ELS) and spot spacing (SS) were set to 0.6-0.8 (as a scale factor of the default values). For each clinical plan, we created four plans with ELS increased to 1.0, 1.2, 1.4, and SS to 1.0 while keeping all other parameters unchanged. All 35 plans (130 fields) were delivered on a clinical proton machine and the beam delivery time was recorded for each field. RESULTS Increasing ELS and SS did not cause target coverage reduction. Increasing ELS had no effect on critical organ-at-risk (OAR) doses or the integral dose, while increasing SS resulted in slightly higher integral and selected OAR doses. Beam-on times were 48.4 ± 9.2 (range: 34.1-66.7) seconds for the clinical plans. Time reductions were 9.2 ± 3.3 s (18.7 ± 5.8%), 11.6 ± 3.5 s (23.1 ± 5.9%), and 14.7 ± 3.9 s (28.9 ± 6.1%) when ELS was changed to 1.0, 1.2, and 1.4, respectively, corresponding to 0.76-0.80 s/layer. SS change had a minimal effect (1.1 ± 1.6 s, or 1.9 ± 2.9%) on the beam-on time. CONCLUSION Increasing the energy layers spacing can reduce the beam delivery time effectively without compromising IMPT plan quality; increasing the SS had no meaningful impact on beam delivery time and resulted in plan-quality degradation in some cases.
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Affiliation(s)
- Mingyao Zhu
- Department of Radiation OncologyEmory University School of MedicineAtlantaGeorgiaUSA
| | - Stella Flampouri
- Department of Radiation OncologyEmory University School of MedicineAtlantaGeorgiaUSA
| | - Alex Stanforth
- Mechanical Engineering, Nuclear Radiological Engineering & Medical PhysicsGeorgia Institute of TechnologyAtlantaGeorgiaUSA
- Emory HealthcareAtlantaGeorgiaUSA
| | - Roelf Slopsema
- Department of Radiation OncologyEmory University School of MedicineAtlantaGeorgiaUSA
| | - Zachary Diamond
- Mechanical Engineering, Nuclear Radiological Engineering & Medical PhysicsGeorgia Institute of TechnologyAtlantaGeorgiaUSA
- Emory HealthcareAtlantaGeorgiaUSA
| | - William LePain
- Mechanical Engineering, Nuclear Radiological Engineering & Medical PhysicsGeorgia Institute of TechnologyAtlantaGeorgiaUSA
- Emory HealthcareAtlantaGeorgiaUSA
| | - Katja Langen
- Department of Radiation OncologyEmory University School of MedicineAtlantaGeorgiaUSA
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Liang X, Beltran CJ, Liu C, Park C, Lu B, Yaddanapudi S, Tan J, Furutani KM. Selecting Optimal Proton Pencil Beam Scanning Plan Parameters to Reduce Dose Discrepancy between Discrete Spot Plan and Continuous Scanning: A Proof-of-Concept Study. Cancers (Basel) 2023; 15:4084. [PMID: 37627112 PMCID: PMC10452710 DOI: 10.3390/cancers15164084] [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: 05/24/2023] [Revised: 07/25/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Pencil beam scanning delivered with continuous scanning has several advantages over conventional discrete spot scanning. Such advantages include improved beam delivery efficiency and reduced beam delivery time. However, a move dose is delivered between consecutive spots with continuous scanning, and current treatment planning systems do not take this into account. Therefore, continuous scanning and discrete spot plans have an inherent dose discrepancy. Using the operating parameters of the state-of-the-art particle therapy system, we conducted a proof-of-concept study in which we systematically generated 28 plans for cubic targets with different combinations of plan parameters and simulated the dose discrepancies between continuous scanning and a planned one. A nomograph to guide the selection of plan parameters was developed to reduce the dose discrepancy. The effectiveness of the nomograph was evaluated with two clinical cases (one prostate and one liver). Plans with parameters guided by the nomograph decreased dose discrepancy than those used standard plan parameters. Specifically, the 2%/2 mm gamma passing rate increased from 96.3% to 100% for the prostate case and from 97.8% to 99.7% for the liver case. The CTV DVH root mean square error decreased from 2.2% to 0.2% for the prostate case and from 1.8% to 0.9% for the liver case. The decreased dose discrepancy may allow the relaxing of the delivery constraint for some cases, leading to greater benefits in continuous scanning. Further investigation is warranted.
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Affiliation(s)
- Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Chris J. Beltran
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Chunbo Liu
- Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Chunjoo Park
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Bo Lu
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Jun Tan
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Keith M. Furutani
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
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Actis O, Mayor A, Meer D, Rechsteiner U, Bolsi A, Lomax AJ, Weber DC. A bi-directional beam-line energy ramping for efficient patient treatment with scanned proton therapy. Phys Med Biol 2023; 68:175001. [PMID: 37506707 DOI: 10.1088/1361-6560/acebb2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/28/2023] [Indexed: 07/30/2023]
Abstract
Objective.The treatment of mobile tumours using Pencil Beam Scanning (PBS) has become more prevalent in the last decade. However, to achieve the same beam delivery quality as for static tumours, treatments have to be combined with motion mitigation techniques, not limited but including, breath hold, gating and re-scanning, which typically prolong treatment time. In this article we present a novel method of bi-directional energy modulation and demonstrate our initial experience in improvement of treatment efficiency. Approach.At Paul Scherrer Institute Gantry 2 mobile tumours are treated by combining PBS with gating and volumetric re-scanning (VR), where the target volume is irradiated multiple times. Initial implementation of VR used only descending beam energies, creating a substantial dead time due to the beam-line initialization (ramping) before each re-scan. In 2019 we commissioned an energy meandering strategy that allows us to avoid beam line ramping in-between energy series while maintaining beam delivery quality.Main results.The measured beam parameters difference for both energy sequence are in the order of the typical daily variations: 0.2 mm in beam position and 0.2 mm in range. Using machine log files, we performed point-to-point dose difference calculations between original and new applications where we observed dose differences of less than 2%. After three years of operation employing bi-directional energy modulation, we have analysed the individual beam delivery time for 181 patients and have compared this to simulations of the timing behaviour assuming uni-directional energy sequence application. Depending on treatment complexity, we obtained plan delivery time reductions of up to 55%, with a median time gain of 17% for all types of treatments.Significance. Bi-directional energy modulation can help improving patient treatment efficiency by reducing delivery times especially for complex and specialised irradiations. It could be implemented in many existing facilities without significant additional hardware upgrades.
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Affiliation(s)
- Oxana Actis
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - Alexandre Mayor
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - David Meer
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - Urs Rechsteiner
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | | | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
- ETH Zurich, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
- University Hospital Zurich, Switzerland
- University Hospital Bern, University of Bern, Switzerland
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10
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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: 0] [Impact Index Per Article: 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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11
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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: 22] [Impact Index Per Article: 11.0] [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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12
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Zhao L, Liu G, Zheng W, Shen J, Lee A, Yan D, Deraniyagala R, Stevens C, Li X, Tang S, Ding X. Building a precise machine-specific time structure of the spot and energy delivery model for a cyclotron-based proton therapy system. Phys Med Biol 2021; 67. [PMID: 34905732 DOI: 10.1088/1361-6560/ac431c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/14/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE We proposed an experimental approach to build a precise machine-specific beam delivery time (BDT) prediction and delivery sequence model for standard, volumetric, and layer repainting delivery based on a cyclotron accelerator system. Approach Test fields and clinical treatment plans' log files were used to experimentally derive three main beam delivery parameters that impacted BDT: energy layer switching time (ELST), spot switching time (SSWT), and spot drill time (SDT). This derived machine-specific model includes standard, volumetric, and layer repainting delivery sequences. A total of 103 clinical treatment fields were used to validate the model. MAIN RESULTS The study found that ELST is not stochastic in this specific machine. Instead, it is actually the data transmission time or energy selection time, whichever takes longer. The validation showed that the accuracy of each component of the BDT matches well between machine log files and the model's prediction. The average total BDT was about (-0.74±3.33)% difference compared to the actual treatment log files, which is improved from the current commercial proton therapy system's prediction (67.22%±26.19%). SIGNIFICANCE An accurate BDT prediction and delivery sequence model was established for an cyclotron-based proton therapy system IBA ProteusPLUS®. Most institutions could adopt this method to build a machine-specific model for their own proton system.
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Affiliation(s)
- Lewei Zhao
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48073-6769, UNITED STATES
| | - Gang Liu
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48073, UNITED STATES
| | - Weili Zheng
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48073, UNITED STATES
| | - Jiajian Shen
- Radiaiton Oncology, Mayo Clinic Arizona, 5777 E Mayo Blvd, Phoenix, Arizona, 85054, UNITED STATES
| | - Andrew Lee
- Texas Center for Proton Therapy, 1501 W Royal Ln, Irving, Texas, 75063, UNITED STATES
| | - Di Yan
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48703, UNITED STATES
| | - Rohan Deraniyagala
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48073, UNITED STATES
| | - Craig Stevens
- Radiation Oncology, William Beaumont Hospital, 3571 W 13 Mile Rd, Royal Oak, 48073, UNITED STATES
| | - Xiaoqiang Li
- Radiation Oncology, Beaumont Health System, 3601 W 13 Miles Rd, Royal Oak, Michigan, 48073, UNITED STATES
| | - Shikui Tang
- Texas Center for Proton Therapy, 1501 W Royal Ln, Irving, Texas, 75063, UNITED STATES
| | - Xuanfeng Ding
- Radiation Oncology, Beaumont Health System, 3571 W 13 Mile Rd, Royal Oak, Michigan, 48073, UNITED STATES
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13
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Yap J, De Franco A, Sheehy S. Future Developments in Charged Particle Therapy: Improving Beam Delivery for Efficiency and Efficacy. Front Oncol 2021; 11:780025. [PMID: 34956897 PMCID: PMC8697351 DOI: 10.3389/fonc.2021.780025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/16/2021] [Indexed: 01/09/2023] Open
Abstract
The physical and clinical benefits of charged particle therapy (CPT) are well recognized. However, the availability of CPT and complete exploitation of dosimetric advantages are still limited by high facility costs and technological challenges. There are extensive ongoing efforts to improve upon these, which will lead to greater accessibility, superior delivery, and therefore better treatment outcomes. Yet, the issue of cost remains a primary hurdle as utility of CPT is largely driven by the affordability, complexity and performance of current technology. Modern delivery techniques are necessary but limited by extended treatment times. Several of these aspects can be addressed by developments in the beam delivery system (BDS) which determines the overall shaping and timing capabilities enabling high quality treatments. The energy layer switching time (ELST) is a limiting constraint of the BDS and a determinant of the beam delivery time (BDT), along with the accelerator and other factors. This review evaluates the delivery process in detail, presenting the limitations and developments for the BDS and related accelerator technology, toward decreasing the BDT. As extended BDT impacts motion and has dosimetric implications for treatment, we discuss avenues to minimize the ELST and overview the clinical benefits and feasibility of a large energy acceptance BDS. These developments support the possibility of advanced modalities and faster delivery for a greater range of treatment indications which could also further reduce costs. Further work to realize methodologies such as volumetric rescanning, FLASH, arc, multi-ion and online image guided therapies are discussed. In this review we examine how increased treatment efficiency and efficacy could be achieved with improvements in beam delivery and how this could lead to faster and higher quality treatments for the future of CPT.
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Affiliation(s)
- Jacinta Yap
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | - Andrea De Franco
- IFMIF Accelerator Development Group, Rokkasho Fusion Institute, National Institutes for Quantum Science and Technology, Aomori, Japan
| | - Suzie Sheehy
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
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14
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Maradia V, Meer D, Weber DC, Lomax AJ, Schippers JM, Psoroulas S. A new emittance selection system to maximize beam transmission for low-energy beams in cyclotron-based proton therapy facilities with gantry. Med Phys 2021; 48:7613-7622. [PMID: 34655083 PMCID: PMC9298197 DOI: 10.1002/mp.15278] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/24/2021] [Accepted: 10/03/2021] [Indexed: 02/06/2023] Open
Abstract
Purpose In proton therapy, the potential of using high‐dose rates in the cancer treatment is being explored. High‐dose rates could improve efficiency and throughput in standard clinical practice, allow efficient utilization of motion mitigation techniques for moving targets, and potentially enhance normal tissue sparing due to the so‐called FLASH effect. However, high‐dose rates are difficult to reach when lower energy beams are applied in cyclotron‐based proton therapy facilities, because they result in large beam sizes and divergences downstream of the degrader, incurring large losses from the cyclotron to the patient position (isocenter). In current facilities, the emittance after the degrader is reduced using circular collimators; however, this does not provide an optimal matching to the acceptance of the following beamline, causing a low transmission for these energies. We, therefore, propose to use a collimation system, asymmetric in both beam size and divergence, resulting in symmetric emittance in both beam transverse planes as required for a gantry system. This new emittance selection, together with a new optics design for the following beamline and gantry, allows a better matching to the beamline acceptance and an improvement of the transmission. Methods We implemented a custom method to design the collimator sizes and shape required to select high emittance, to be transported by the following beamline using new beam optics (designed with TRANSPORT) to maximize acceptance matching. For predicting the transmission in the new configuration (new collimators + optics), we used Monte Carlo simulations implemented in BDSIM, implementing a model of PSI Gantry 2 which we benchmarked against measurements taken in the current clinical scenario (circular collimators + clinical optics). Results From the BDSIM simulations, we found that the new collimator system and matching beam optics results in an overall transmission from the cyclotron to the isocenter for a 70 MeV beam of 0.72%. This is an improvement of almost a factor of 6 over the current clinical performance (0.13% transmission). The new optics satisfies clinical beam requirements at the isocenter. Conclusions We developed a new emittance collimation system for PSI's PROSCAN beamline which, by carefully selecting beam size and divergence asymmetrically, increases the beam transmission for low‐energy beams in current state‐of‐the‐art cyclotron‐based proton therapy gantries. With these improvements, we could predict almost 1% transmission for low‐energy beams at PSI's Gantry 2. Such a system could easily be implemented in facilities interested in increasing dose rates for efficient motion mitigation and FLASH experiments alike.
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Affiliation(s)
- Vivek Maradia
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland.,Department of Physics, ETH Zurich, Zurich, Switzerland
| | - David Meer
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland.,Department of Physics, ETH Zurich, Zurich, Switzerland
| | | | - Serena Psoroulas
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
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15
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Paganetti H, Beltran C, Both S, Dong L, Flanz J, Furutani K, Grassberger C, Grosshans DR, Knopf AC, Langendijk JA, Nystrom H, Parodi K, Raaymakers BW, Richter C, Sawakuchi GO, Schippers M, Shaitelman SF, Teo BKK, Unkelbach J, Wohlfahrt P, Lomax T. Roadmap: proton therapy physics and biology. Phys Med Biol 2021; 66. [DOI: 10.1088/1361-6560/abcd16] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022]
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16
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Mitigation of motion effects in pencil-beam scanning - Impact of repainting on 4D robustly optimized proton treatment plans for hepatocellular carcinoma. Z Med Phys 2020; 32:63-73. [PMID: 33131995 PMCID: PMC9948857 DOI: 10.1016/j.zemedi.2020.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/29/2020] [Accepted: 08/14/2020] [Indexed: 12/27/2022]
Abstract
Proton fields delivered by the active scanning technique can be interfered with the intrafractional motion. This in-silico study seeks to mitigate the dosimetric impacts of motion artifacts, especially its interplay with the time-modulated dose delivery. Here four-dimensional (4d) robust optimization and dose repainting, which is the multiple application of the same field with reduced fluence, were combined. Two types of repainting were considered: layered and volumetric repainting. The time-resolved dose calculation, which is necessary to quantify the interplay effect, was integrated into the treatment planning system and validated. Nine clinical cases of hepatocellular carcinoma (HCC) showing motion in the range of 0.4-1.5cm were studied. It was found that the repainted delivery of 4D robustly optimized plans reduced the impact of interplay effect as quantified by the homogeneity index within the clinical target volume (CTV) to a tolerable level. Similarly, the fractional over- and underdosage was reduced sufficiently for some HCC cases to achieve the purpose of motion management. This holds true for both investigated types of repainting with small dosimetric advantages of volume repainting over layered repainting. Volume repainting, however, cannot be applied clinically in proton centers with slow energy changes. Thus, it served as a reference in the in-silico evaluation. It is recommended to perform the dynamic dose calculation for individual cases to judge if robust optimization in conjunction with repainting is sufficient to keep the interplay effect within bounds.
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17
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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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18
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van de Water S, Belosi MF, Albertini F, Winterhalter C, Weber DC, Lomax AJ. Shortening delivery times for intensity-modulated proton therapy by reducing the number of proton spots: an experimental verification. Phys Med Biol 2020; 65:095008. [PMID: 32155594 DOI: 10.1088/1361-6560/ab7e7c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Delivery times of intensity-modulated proton therapy (IMPT) can be shortened by reducing the number of spots in the treatment plan, but this may affect clinical plan delivery. Here, we assess the experimental deliverability, accuracy and time reduction of spot-reduced treatment planning for a clinical case, as well as its robustness. For a single head-and-neck cancer patient, a spot-reduced plan was generated and compared with the conventional clinical plan. The number of proton spots was reduced using the iterative 'pencil beam resampling' technique. This involves repeated inverse optimization, while adding in each iteration a small sample of randomly selected spots and subsequently excluding low-weighted spots until plan quality deteriorates. Field setup was identical for both plans and comparable dosimetric quality was a prerequisite. Both IMPT plans were delivered on PSI Gantry 2 and measured in water, while delivery log-files were used to extract delivery times and reconstruct the delivered dose via Monte-Carlo dose calculations. In addition, robustness simulations were performed to assess sensitivity to machine inaccuracies and errors in patient setup and proton range. The number of spots was reduced by 96% (from 33 855 to 1510 in total) without compromising plan quality. The spot-reduced plan was deliverable on our gantry in standard clinical mode and resulted in average delivery times per field being shortened by 46% (from 51.2 to 27.6 s). For both plans, differences between measured and calculated dose were within clinical tolerance for patient-specific verifications and Monte-Carlo dose reconstructions were in accordance with clinical experience. The spot-reduced plan was slightly more sensitive to machine inaccuracies, but more robust against setup and range errors. In conclusion, for an example head-and-neck case, spot-reduced IMPT planning provided a deliverable treatment plan and enabled considerable shortening of the delivery time (∼50%) without compromising plan quality or delivery accuracy, and without substantially affecting robustness.
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Affiliation(s)
- Steven van de Water
- Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI, Switzerland
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19
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20
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Lee E, Perry D, Speth J, Zhang Y, Xiao Z, Mascia A. Measurement-based study on characterizing symmetric and asymmetric respiratory motion interplay effect on target dose distribution in the proton pencil beam scanning. J Appl Clin Med Phys 2020; 21:59-67. [PMID: 32170992 PMCID: PMC7170285 DOI: 10.1002/acm2.12846] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/17/2020] [Accepted: 02/10/2020] [Indexed: 12/25/2022] Open
Abstract
Pencil beam scanning proton therapy makes possible intensity modulation, resulting in improved target dose conformity and organ‐at‐risk (OAR) dose sparing. This benefit, however, results in increased sensitivity to certain clinical and beam delivery parameters, such as respiratory motion. These effects can cause plan degeneration, which could lead to decreased tumor dose or increased OAR dose. This study evaluated the measurements of proton pencil beam scanning delivery made with a 2D ion chamber array in solid water on a 1D motion platform, where respiratory motion was simulated using sine and cosine4 waves representing sinusoidal symmetric and realistic asymmetric breathing motions, respectively. Motion amplitudes were 0.5 cm and 1 cm corresponding to 1 cm and 2 cm of maximum respiratory excursions, respectively, with 5 sec fixed breathing cycle. The treatment plans were created to mimic spherical targets of 3 cm or 10 cm diameter located at 5 cm or 1 cm depth in solid water phantom. A reference RBE dose of 200 cGy per fraction was delivered in 1, 5, 10, and 15 fractions for each dataset. We evaluated dose conformity and uniformity at the center plane of targets by using the Conformation Number and the Homogeneity Index, respectively. Results indicated that dose conformity as well as homogeneity was more affected by motion for smaller targets. Dose conformity was better achieved for symmetric breathing patterns than asymmetric breathing patterns regardless of the number of fractions. The presence of a range shifter with shallow targets reduced the motion effect by improving dose homogeneity. While motion effects are known to be averaged out over the course of multifractional treatments, this might not be true for proton pencil beam scanning under asymmetrical breathing pattern.
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Affiliation(s)
- Eunsin Lee
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Daniel Perry
- Department of Radiation Oncology, University of Cincinnati Medical Center, Cincinnati, OH, USA
| | - Joseph Speth
- Department of Radiation Oncology, University of Cincinnati Medical Center, Cincinnati, OH, USA
| | - Yongbin Zhang
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Zhiyan Xiao
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Anthony Mascia
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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21
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Nesteruk KP, Calzolaio C, Meer D, Rizzoglio V, Seidel M, Schippers JM. Large energy acceptance gantry for proton therapy utilizing superconducting technology. ACTA ACUST UNITED AC 2019; 64:175007. [DOI: 10.1088/1361-6560/ab2f5f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Bertholet J, Knopf A, Eiben B, McClelland J, Grimwood A, Harris E, Menten M, Poulsen P, Nguyen DT, Keall P, Oelfke U. Real-time intrafraction motion monitoring in external beam radiotherapy. Phys Med Biol 2019; 64:15TR01. [PMID: 31226704 PMCID: PMC7655120 DOI: 10.1088/1361-6560/ab2ba8] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/10/2019] [Accepted: 06/21/2019] [Indexed: 12/25/2022]
Abstract
Radiotherapy (RT) aims to deliver a spatially conformal dose of radiation to tumours while maximizing the dose sparing to healthy tissues. However, the internal patient anatomy is constantly moving due to respiratory, cardiac, gastrointestinal and urinary activity. The long term goal of the RT community to 'see what we treat, as we treat' and to act on this information instantaneously has resulted in rapid technological innovation. Specialized treatment machines, such as robotic or gimbal-steered linear accelerators (linac) with in-room imaging suites, have been developed specifically for real-time treatment adaptation. Additional equipment, such as stereoscopic kilovoltage (kV) imaging, ultrasound transducers and electromagnetic transponders, has been developed for intrafraction motion monitoring on conventional linacs. Magnetic resonance imaging (MRI) has been integrated with cobalt treatment units and more recently with linacs. In addition to hardware innovation, software development has played a substantial role in the development of motion monitoring methods based on respiratory motion surrogates and planar kV or Megavoltage (MV) imaging that is available on standard equipped linacs. In this paper, we review and compare the different intrafraction motion monitoring methods proposed in the literature and demonstrated in real-time on clinical data as well as their possible future developments. We then discuss general considerations on validation and quality assurance for clinical implementation. Besides photon RT, particle therapy is increasingly used to treat moving targets. However, transferring motion monitoring technologies from linacs to particle beam lines presents substantial challenges. Lessons learned from the implementation of real-time intrafraction monitoring for photon RT will be used as a basis to discuss the implementation of these methods for particle RT.
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Affiliation(s)
- Jenny Bertholet
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS
Foundation Trust, London, United
Kingdom
- Author to whom any correspondence should be
addressed
| | - Antje Knopf
- Department of Radiation Oncology,
University Medical Center
Groningen, University of Groningen, The
Netherlands
| | - Björn Eiben
- Department of Medical Physics and Biomedical
Engineering, Centre for Medical Image Computing, University College London, London,
United Kingdom
| | - Jamie McClelland
- Department of Medical Physics and Biomedical
Engineering, Centre for Medical Image Computing, University College London, London,
United Kingdom
| | - Alexander Grimwood
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS
Foundation Trust, London, United
Kingdom
| | - Emma Harris
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS
Foundation Trust, London, United
Kingdom
| | - Martin Menten
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS
Foundation Trust, London, United
Kingdom
| | - Per Poulsen
- Department of Oncology, Aarhus University Hospital, Aarhus,
Denmark
| | - Doan Trang Nguyen
- ACRF Image X Institute, University of Sydney, Sydney,
Australia
- School of Biomedical Engineering,
University of Technology
Sydney, Sydney, Australia
| | - Paul Keall
- ACRF Image X Institute, University of Sydney, Sydney,
Australia
| | - Uwe Oelfke
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS
Foundation Trust, London, United
Kingdom
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23
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Meijers A, Jakobi A, Stützer K, Guterres Marmitt G, Both S, Langendijk JA, Richter C, Knopf A. Log file-based dose reconstruction and accumulation for 4D adaptive pencil beam scanned proton therapy in a clinical treatment planning system: Implementation and proof-of-concept. Med Phys 2019; 46:1140-1149. [DOI: 10.1002/mp.13371] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 12/27/2022] Open
Affiliation(s)
- A. Meijers
- Department of Radiation Oncology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - A. Jakobi
- Faculty of Medicine; University Hospital Carl Gustav Carus; OncoRay - National Center for Radiation Research in Oncology; Technische Universität Dresden; Helmholtz-Zentrum Dresden - Rossendorf; Dresden Germany
- Department of Radiotherapy and Radiation Oncology; Faculty of Medicine; University Hospital Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
- Helmholtz-Zentrum Dresden - Rossendorf; Institute of Radiooncology - OncoRay; Dresden Germany
| | - K. Stützer
- Faculty of Medicine; University Hospital Carl Gustav Carus; OncoRay - National Center for Radiation Research in Oncology; Technische Universität Dresden; Helmholtz-Zentrum Dresden - Rossendorf; Dresden Germany
- Helmholtz-Zentrum Dresden - Rossendorf; Institute of Radiooncology - OncoRay; Dresden Germany
| | - G. Guterres Marmitt
- Department of Radiation Oncology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - S. Both
- Department of Radiation Oncology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - J. A. Langendijk
- Department of Radiation Oncology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - C. Richter
- Faculty of Medicine; University Hospital Carl Gustav Carus; OncoRay - National Center for Radiation Research in Oncology; Technische Universität Dresden; Helmholtz-Zentrum Dresden - Rossendorf; Dresden Germany
- Department of Radiotherapy and Radiation Oncology; Faculty of Medicine; University Hospital Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
- Helmholtz-Zentrum Dresden - Rossendorf; Institute of Radiooncology - OncoRay; Dresden Germany
- German Cancer Consortium (DKTK), Partner Site Dresden; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - A. Knopf
- Department of Radiation Oncology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
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