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Han D, Tong J, Yang Y, Liu H, Liang X, Yaddanapudi S, Park C, Tan J, Furutani K, Beltran C, Lu B. Optimizing spot intensity with lower bound constraints for IMPT: Exposing shortcomings and introducing an enhanced strategy. Med Phys 2024. [PMID: 38922975 DOI: 10.1002/mp.17265] [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: 02/15/2024] [Revised: 05/16/2024] [Accepted: 06/09/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Intensity Modulated Proton Therapy (IMPT) is a sophisticated radiation treatment allowing for precise dose distributions. However, conventional spot selection strategies in IMPT face challenges, particularly with minimum monitor unit (MU) constraints, affecting planning quality and efficiency. PURPOSE This study introduces an innovative Two-Stage Mixed Integer Linear Programming (MILP) method to optimize spot intensity in IMPT with Lower Bound (LB) constraints. This method seeks to improve treatment planning efficiency and precision, overcoming limitations of existing strategies. METHODS Our approach evaluates prevalent IMPT spot selection strategies, identifying their limitations, especially concerning MU constraints. We integrated LB constraints into a MILP framework, using a novel three-phase strategy for spot pool selection, to enhance performance over traditional heuristic methods and L1 + L∞ strategies. The method's efficacy was tested in eight study cases, using Dose-Volume Histograms (DVHs), spot selection efficiency, and computation time analysis for benchmarking against established methods. RESULTS The proposed method showed superior performance in DVH quality, adhering to LB constraints while maintaining high-quality treatment plans. It outperformed existing techniques in spot selection, reducing unnecessary spots and balancing precision with efficiency. Cases studies confirmed the method's effectiveness in producing clinically feasible plans with enhanced dose distributions and reduced hotspots, especially in cases with elevated LB constraints. CONCLUSIONS Our Two-Stage MILP strategy signifies a significant advancement in IMPT treatment planning. By incorporating LB constraints directly into the optimization process, it achieves superior plan quality and deliverability compared to current methods. This approach is particularly advantageous in clinical settings requiring minimum spot number and high MU LB constraints, offering the potential for improved patient outcomes through more precise and efficient radiation therapy plans.
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Affiliation(s)
- Dong Han
- Department of Industrial and Systems Engineering, University of Florida, Gainesville, Florida, USA
| | - Jingdong Tong
- Department of Industrial and Systems Engineering, University of Florida, Gainesville, Florida, USA
| | - Yu Yang
- Department of Industrial and Systems Engineering, University of Florida, Gainesville, Florida, USA
| | - Hongcheng Liu
- Department of Industrial and Systems Engineering, University of Florida, Gainesville, Florida, USA
| | - Xiaoying Liang
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Sridhar Yaddanapudi
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Chunjoo Park
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Jun Tan
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Keith Furutani
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Chris Beltran
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
| | - Bo Lu
- Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA
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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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Jenny T, Duetschler A, Giger A, Pusterla O, Safai S, Weber DC, Lomax AJ, Zhang Y. Technical note: Towards more realistic 4DCT(MRI) numerical lung phantoms. Med Phys 2024; 51:579-590. [PMID: 37166067 DOI: 10.1002/mp.16451] [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: 11/29/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Numerical 4D phantoms, together with associated ground truth motion, offer a flexible and comprehensive data set for realistic simulations in radiotherapy and radiology in target sites affected by respiratory motion. PURPOSE We present an openly available upgrade to previously reported methods for generating realistic 4DCT lung numerical phantoms, which now incorporate respiratory ribcage motion and improved lung density representation throughout the breathing cycle. METHODS Density information of reference CTs, toget her with motion from multiple breathing cycle 4DMRIs have been combined to generate synthetic 4DCTs (4DCT(MRI)s). Inter-subject correspondence between the CT and MRI anatomy was first established via deformable image registration (DIR) of binary masks of the lungs and ribcage. Ribcage and lung motions were extracted independently from the 4DMRIs using DIR and applied to the corresponding locations in the CT after post-processing to preserve sliding organ motion. In addition, based on the Jacobian determinant of the resulting deformation vector fields, lung densities were scaled on a voxel-wise basis to more accurately represent changes in local lung density. For validating this process, synthetic 4DCTs, referred to as 4DCT(CT)s, were compared to the originating 4DCTs using motion extracted from the latter, and the dosimetric impact of the new features of ribcage motion and density correction were analyzed using pencil beam scanned proton 4D dose calculations. RESULTS Lung density scaling led to a reduction of maximum mean lung Hounsfield units (HU) differences from 45 to 12 HU when comparing simulated 4DCT(CT)s to their originating 4DCTs. Comparing 4D dose distributions calculated on the enhanced 4DCT(CT)s to those on the original 4DCTs yielded 2%/2 mm gamma pass rates above 97% with an average improvement of 1.4% compared to previously reported phantoms. CONCLUSIONS A previously reported 4DCT(MRI) workflow has been successfully improved and the resulting numerical phantoms exhibit more accurate lung density representations and realistic ribcage motion.
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Affiliation(s)
- Timothy Jenny
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zürich, Zürich, Switzerland
| | - Alisha Duetschler
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zürich, Zürich, Switzerland
| | - Alina Giger
- Department of Biomedical Engineering, University of Basel, Basel, Switzerland
- Center for Medical Image Analysis & Navigation, University of Basel, Basel, Switzerland
| | - Orso Pusterla
- Department of Biomedical Engineering, University of Basel, Basel, Switzerland
- Department of Radiology, Division of Radiological Physics, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, Zürich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zürich, Zürich, Switzerland
| | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, 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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Pennock M, Wei S, Cheng C, Lin H, Hasan S, Chhabra AM, Choi JI, Bakst RL, Kabarriti R, Simone II CB, Lee NY, Kang M, Press RH. Proton Bragg Peak FLASH Enables Organ Sparing and Ultra-High Dose-Rate Delivery: Proof of Principle in Recurrent Head and Neck Cancer. Cancers (Basel) 2023; 15:3828. [PMID: 37568644 PMCID: PMC10417542 DOI: 10.3390/cancers15153828] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Proton pencil-beam scanning (PBS) Bragg peak FLASH combines ultra-high dose rate delivery and organ-at-risk (OAR) sparing. This proof-of-principle study compared dosimetry and dose rate coverage between PBS Bragg peak FLASH and PBS transmission FLASH in head and neck reirradiation. PBS Bragg peak FLASH plans were created via the highest beam single energy, range shifter, and range compensator, and were compared to PBS transmission FLASH plans for 6 GyE/fraction and 10 GyE/fraction in eight recurrent head and neck patients originally treated with quad shot reirradiation (14.8/3.7 CGE). The 6 GyE/fraction and 10 GyE/fraction plans were also created using conventional-rate intensity-modulated proton therapy techniques. PBS Bragg peak FLASH, PBS transmission FLASH, and conventional plans were compared for OAR sparing, FLASH dose rate coverage, and target coverage. All FLASH OAR V40 Gy/s dose rate coverage was 90-100% at 6 GyE and 10 GyE for both FLASH modalities. PBS Bragg peak FLASH generated dose volume histograms (DVHs) like those of conventional therapy and demonstrated improved OAR dose sparing over PBS transmission FLASH. All the modalities had similar CTV coverage. PBS Bragg peak FLASH can deliver conformal, ultra-high dose rate FLASH with a two-millisecond delivery of the minimum MU per spot. PBS Bragg peak FLASH demonstrated similar dose rate coverage to PBS transmission FLASH with improved OAR dose-sparing, which was more pronounced in the 10 GyE/fraction than in the 6 GyE/fraction. This feasibility study generates hypotheses for the benefits of FLASH in head and neck reirradiation and developing biological models.
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Affiliation(s)
- Michael Pennock
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY 10461, USA;
| | - Shouyi Wei
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Chingyun Cheng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08901, USA;
| | - Haibo Lin
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Shaakir Hasan
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Arpit M. Chhabra
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - J. Isabelle Choi
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - Richard L. Bakst
- Department of Radiation Oncology—Radiation Oncology Associates, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Rafi Kabarriti
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY 10461, USA;
| | - Charles B. Simone II
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - Nancy Y. Lee
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Minglei Kang
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Robert H. Press
- Department of Radiation Oncology, Baptist Health South Florida, Miami Cancer Institute, Miami, FL 33176, USA;
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Worm ES, Thomsen JB, Johansen JG, Poulsen PR. A simple method to measure the gating latencies in photon and proton based radiotherapy using a scintillating crystal. Med Phys 2023. [PMID: 37075173 DOI: 10.1002/mp.16418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 10/28/2022] [Accepted: 03/28/2023] [Indexed: 04/21/2023] Open
Abstract
BACKGROUND In respiratory gated radiotherapy, low latency between target motion into and out of the gating window and actual beam-on and beam-off is crucial for the treatment accuracy. However, there is presently a lack of guidelines and accurate methods for gating latency measurements. PURPOSE To develop a simple and reliable method for gating latency measurements that work across different radiotherapy platforms. METHODS Gating latencies were measured at a Varian ProBeam (protons, RPM gating system) and TrueBeam (photons, TrueBeam gating system) accelerator. A motion-stage performed 1 cm vertical sinusoidal motion of a marker block that was optically tracked by the gating system. An amplitude gating window was set to cover the posterior half of the motion (0-0.5 cm). Gated beams were delivered to a 5 mm cubic scintillating ZnSe:O crystal that emitted visible light when irradiated, thereby directly showing when the beam was on. During gated beam delivery, a video camera acquired images at 120 Hz of the moving marker block and light-emitting crystal. After treatment, the block position and crystal light intensity were determined in all video frames. Two methods were used to determine the gate-on (τon ) and gate-off (τoff ) latencies. By method 1, the video was synchronized with gating log files by temporal alignment of the same block motion recorded in both the video and the log files. τon was defined as the time from the block entered the gating window (from gating log files) to the actual beam-on as detected by the crystal light. Similarly, τoff was the time from the block exited the gating window to beam-off. By method 2, τon and τoff were found from the videos alone using motion of different sine periods (1-10 s). In each video, a sinusoidal fit of the block motion provided the times Tmin of the lowest block position. The mid-time, Tmid-light , of each beam-on period was determined as the time halfway between crystal light signal start and end. It can be shown that the directly measurable quantity Tmid-light - Tmin = (τoff +τon )/2, which provided the sum (τoff +τon ) of the two latencies. It can also be shown that the beam-on (i.e., crystal light) duration ΔTlight increases linearly with the sine period and depends on τoff - τon : ΔTlight = constant•period+(τoff - τon ). Hence, a linear fit of ΔTlight as a function of the period provided the difference of the two latencies. From the sum (τoff +τon ) and difference (τoff - τon ), the individual latencies were determined. RESULTS Method 1 resulted in mean (±SD) latencies of τon = 255 ± 33 ms, τoff = 82 ± 15 ms for the ProBeam and τon = 84 ± 13 ms, τoff = 44 ± 11 ms for the TrueBeam. Method 2 resulted in latencies of τon = 255 ± 23 ms, τoff = 95 ± 23 ms for the ProBeam and τon = 83 ± 8 ms, τoff = 46 ± 8 ms for the TrueBeam. Hence, the mean latencies determined by the two methods agreed within 13 ms for the ProBeam and within 2 ms for the TrueBeam. CONCLUSIONS A novel, simple and low-cost method for gating latency measurements that work across different radiotherapy platforms was demonstrated. Only the TrueBeam fully fulfilled the AAPM TG-142 recommendation of maximum 100 ms latencies.
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Affiliation(s)
| | - Jakob Borup Thomsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Per Rugaard Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Zhang Y, Trnkova P, Toshito T, Heijmen B, Richter C, Aznar M, Albertini F, Bolsi A, Daartz J, Bertholet J, Knopf A. A survey of practice patterns for real-time intrafractional motion-management in particle therapy. Phys Imaging Radiat Oncol 2023; 26:100439. [PMID: 37124167 PMCID: PMC10133874 DOI: 10.1016/j.phro.2023.100439] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 05/02/2023] Open
Abstract
Background and purpose Organ motion compromises accurate particle therapy delivery. This study reports on the practice patterns for real-time intrafractional motion-management in particle therapy to evaluate current clinical practice and wishes and barriers to implementation. Materials and methods An institutional questionnaire was distributed to particle therapy centres worldwide (7/2020-6/2021) asking which type(s) of real-time respiratory motion management (RRMM) methods were used, for which treatment sites, and what were the wishes and barriers to implementation. This was followed by a three-round DELPHI consensus analysis (10/2022) to define recommendations on required actions and future vision. With 70 responses from 17 countries, response rate was 100% for Europe (23/23 centres), 96% for Japan (22/23) and 53% for USA (20/38). Results Of the 68 clinically operational centres, 85% used RRMM, with 41% using both rescanning and active methods. Sixty-four percent used active-RRMM for at least one treatment site, mostly with gating guided by an external marker. Forty-eight percent of active-RRMM users wished to expand or change their RRMM technique. The main barriers were technical limitations and limited resources. From the DELPHI analysis, optimisation of rescanning parameters, improvement of motion models, and pre-treatment 4D evaluation were unanimously considered clinically important future focus. 4D dose calculation was identified as the top requirement for future commercial treatment planning software. Conclusion A majority of particle therapy centres have implemented RRMM. Still, further development and clinical integration were desired by most centres. Joint industry, clinical and research efforts are needed to translate innovation into efficient workflows for broad-scale implementation.
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Affiliation(s)
- Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Petra Trnkova
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Toshiyuki Toshito
- Nagoya Proton Therapy Center, Nagoya City University West Medical Center, Nagoya, Japan
| | - Ben Heijmen
- Department of Radiotherapy, Erasmus University Medical Center (Erasmus MC), Rotterdam, the Netherlands
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Marianne Aznar
- Faculty of Biology, Medicine and Health, Division of Cancer Sciences, University of Manchester, United Kingdom
| | | | - Alexandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Juliane Daartz
- F. Burr Proton Therapy, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - Jenny Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Antje Knopf
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Institute for Medical Engineering and Medical Informatics, School of Life Science FHNW, Muttenz, Switzerland
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Nankali S, Worm ES, Thomsen JB, Stick LB, Bertholet J, Høyer M, Weber B, Mortensen HR, Poulsen PR. Intrafraction tumor motion monitoring and dose reconstruction for liver pencil beam scanning proton therapy. Front Oncol 2023; 13:1112481. [PMID: 36937392 PMCID: PMC10019817 DOI: 10.3389/fonc.2023.1112481] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Background Pencil beam scanning (PBS) proton therapy can provide highly conformal target dose distributions and healthy tissue sparing. However, proton therapy of hepatocellular carcinoma (HCC) is prone to dosimetrical uncertainties induced by respiratory motion. This study aims to develop intra-treatment tumor motion monitoring during respiratory gated proton therapy and combine it with motion-including dose reconstruction to estimate the delivered tumor doses for individual HCC treatment fractions. Methods Three HCC-patients were planned to receive 58 GyRBE (n=2) or 67.5 GyRBE (n=1) of exhale respiratory gated PBS proton therapy in 15 fractions. The treatment planning was based on the exhale phase of a 4-dimensional CT scan. Daily setup was based on cone-beam CT (CBCT) imaging of three implanted fiducial markers. An external marker block (RPM) on the patient's abdomen was used for exhale gating in free breathing. This study was based on 5 fractions (patient 1), 1 fraction (patient 2) and 6 fractions (patient 3) where a post-treatment control CBCT was available. After treatment, segmented 2D marker positions in the post-treatment CBCT projections provided the estimated 3D motion trajectory during the CBCT by a probability-based method. An external-internal correlation model (ECM) that estimated the tumor motion from the RPM motion was built from the synchronized RPM signal and marker motion in the CBCT. The ECM was then used to estimate intra-treatment tumor motion. Finally, the motion-including CTV dose was estimated using a dose reconstruction method that emulates tumor motion in beam's eye view as lateral spot shifts and in-depth motion as changes in the proton beam energy. The CTV homogeneity index (HI) The CTV homogeneity index (HI) was calculated as D 2 % - D 98 % D 50 % × 100 % . Results The tumor position during spot delivery had a root-mean-square error of 1.3 mm in left-right, 2.8 mm in cranio-caudal and 1.7 mm in anterior-posterior directions compared to the planned position. On average, the CTV HI was larger than planned by 3.7%-points (range: 1.0-6.6%-points) for individual fractions and by 0.7%-points (range: 0.3-1.1%-points) for the average dose of 5 or 6 fractions. Conclusions A method to estimate internal tumor motion and reconstruct the motion-including fraction dose for PBS proton therapy of HCC was developed and demonstrated successfully clinically.
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Affiliation(s)
- Saber Nankali
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Saber Nankali,
| | | | - Jakob Borup Thomsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Jenny Bertholet
- Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - Morten Høyer
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Britta Weber
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Per Rugaard Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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9
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Zaki P, Chuong MD, Schaub SK, Lo SS, Ibrahim M, Apisarnthanarax S. Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma. Technol Cancer Res Treat 2023; 22:15330338231206335. [PMID: 37908130 PMCID: PMC10621304 DOI: 10.1177/15330338231206335] [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: 08/17/2022] [Revised: 08/21/2023] [Accepted: 09/21/2023] [Indexed: 11/02/2023] Open
Abstract
External beam radiation therapy (EBRT) has increasingly been utilized in the treatment of hepatocellular carcinoma (HCC) due to technological advances with positive clinical outcomes. Innovations in EBRT include improved image guidance, motion management, treatment planning, and highly conformal techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT). Moreover, proton beam therapy (PBT) and magnetic resonance image-guided radiation therapy (MRgRT) have expanded the capabilities of EBRT. PBT offers the advantage of minimizing low- and moderate-dose radiation to the surrounding normal tissue, thereby preserving uninvolved liver and allowing for dose escalation. MRgRT provides the advantage of improved soft tissue delineation compared to computerized tomography (CT) guidance. Additionally, MRgRT with online adaptive therapy is particularly useful for addressing motion not otherwise managed and reducing high-dose radiation to the normal tissue such as the stomach and bowel. PBT and online adaptive MRgRT are emerging technological advancements in EBRT that may provide a significant clinical benefit for patients with HCC.
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Affiliation(s)
- Peter Zaki
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Michael D. Chuong
- Department of Radiation Oncology, Miami Cancer Institute, Miami, FL, USA
| | - Stephanie K. Schaub
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Simon S. Lo
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Mariam Ibrahim
- School of Medicine, St. George's University, St. George's, Grenada
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10
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Schneider S, Stefanowicz S, Jentsch C, Lohaus F, Thiele J, Haak D, Valentini C, Platzek I, G. C. Troost E, Hoffmann AL. Reduction of intrafraction pancreas motion using an abdominal corset compatible with proton therapy and MRI. Clin Transl Radiat Oncol 2022; 38:111-116. [DOI: 10.1016/j.ctro.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
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11
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Dionisi F, Scartoni D, Fracchiolla F, Giacomelli I, Siniscalchi B, Goanta L, Cianchetti M, Sanguineti G, Brolese A. Proton therapy in the treatment of hepatocellular carcinoma. Front Oncol 2022; 12:959552. [PMID: 36003769 PMCID: PMC9393743 DOI: 10.3389/fonc.2022.959552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/13/2022] [Indexed: 12/24/2022] Open
Abstract
Liver cancer represents one of the most common causes of death from cancer worldwide. Hepatocellular carcinoma (HCC) accounts for 90% of all primary liver cancers. Among local therapies, evidence regarding the use of radiation therapy is growing. Proton therapy currently represents the most advanced radiation therapy technique with unique physical properties which fit well with liver irradiation. Here, in this review, we aim to 1) illustrate the rationale for the use of proton therapy (PT) in the treatment of HCC, 2) discuss the technical challenges of advanced PT in this disease, 3) review the major clinical studies regarding the use of PT for HCC, and 4) analyze the potential developments and future directions of PT in this setting.
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Affiliation(s)
- Francesco Dionisi
- Department of Radiation Oncology, IRCCS Regina Elena National Cancer Institute, Rome, Italy
- *Correspondence: Francesco Dionisi,
| | - Daniele Scartoni
- Proton Therapy Unit, Azienda Provinciale per i Servizi Sanitari, Trento, Italy
| | | | - Irene Giacomelli
- Proton Therapy Unit, Azienda Provinciale per i Servizi Sanitari, Trento, Italy
| | | | - Lucia Goanta
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Napoli, Italy
| | - Marco Cianchetti
- Proton Therapy Unit, Azienda Provinciale per i Servizi Sanitari, Trento, Italy
| | - Giuseppe Sanguineti
- Department of Radiation Oncology, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Alberto Brolese
- General Surgery & Hepato-Pancreato-Biliary Unit, Azienda Provinciale per i Servizi Sanitari, Trento, Italy
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12
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Pakela JM, Knopf A, Dong L, Rucinski A, Zou W. Management of Motion and Anatomical Variations in Charged Particle Therapy: Past, Present, and Into the Future. Front Oncol 2022; 12:806153. [PMID: 35356213 PMCID: PMC8959592 DOI: 10.3389/fonc.2022.806153] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/04/2022] [Indexed: 12/14/2022] Open
Abstract
The major aim of radiation therapy is to provide curative or palliative treatment to cancerous malignancies while minimizing damage to healthy tissues. Charged particle radiotherapy utilizing carbon ions or protons is uniquely suited for this task due to its ability to achieve highly conformal dose distributions around the tumor volume. For these treatment modalities, uncertainties in the localization of patient anatomy due to inter- and intra-fractional motion present a heightened risk of undesired dose delivery. A diverse range of mitigation strategies have been developed and clinically implemented in various disease sites to monitor and correct for patient motion, but much work remains. This review provides an overview of current clinical practices for inter and intra-fractional motion management in charged particle therapy, including motion control, current imaging and motion tracking modalities, as well as treatment planning and delivery techniques. We also cover progress to date on emerging technologies including particle-based radiography imaging, novel treatment delivery methods such as tumor tracking and FLASH, and artificial intelligence and discuss their potential impact towards improving or increasing the challenge of motion mitigation in charged particle therapy.
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Affiliation(s)
- Julia M Pakela
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
| | - Antje Knopf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.,Department I of Internal Medicine, Center for Integrated Oncology Cologne, University Hospital of Cologne, Cologne, Germany
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
| | - Antoni Rucinski
- Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
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13
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He P, Li Q. Impact of Different Synchrotron Flattop Operation Modes on 4D Dosimetric Uncertainties for Scanned Carbon-Ion Beam Delivery. Front Oncol 2022; 12:806742. [PMID: 35223486 PMCID: PMC8873937 DOI: 10.3389/fonc.2022.806742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/17/2022] [Indexed: 11/25/2022] Open
Abstract
Purpose The characteristic of pulsed beam delivery for synchrotron-based carbon-ion radiotherapy has led to the emergence of many scanning scenarios in order to improve the treatment efficiency and accuracy of moving target volume. Here, we aim to evaluate a novel breathing guidance motion mitigation performance under different synchrotron flattop operation modes in carbon-ion radiotherapy. Methods With the use of twelve 4DCT datasets of lung cancer patients who had been treated with respiratory-gated carbon-ion pencil beam therapy, range-adapted internal target volume (raITV) plans were optimized. Under the fixed flattop with single-energy and extended flattop with multi-energy synchrotron operation modes, the 4D treatments with breathing guidance and free breathing-based gated phase-controlled rescanning (PCR) beam delivery were simulated. Dose metrics (D95 and D5–D95 in clinical target volume (CTV)) and treatment time of the resulting 4D plans were compared. Results The two synchrotron operation modes provided different scanning dynamics. For the free breathing-based PCR method delivered in the extended flattop operation mode, the averaged CTV-D95 values were 90.4% ± 3.7%, 95.4% ± 1.7%, 96.9% ± 1.5%, 97.2% ± 1.5%, and 97.3% ± 1.5% for the 1-scanning, 2-PCR, 4-PCR, 6-PCR, and 8-PCR, respectively. For the breathing guidance-based PCR method delivered in the extended flattop mode, these values were 89.1% ± 4.0%, 97.0% ± 1.4%, 98.2% ± 0.7%, 98.6% ± 0.7%, and 98.9% ± 0.7%, respectively. However, CTV-D95 significantly increased to 98.5% ± 1.0% even with just 1-scanning breathing guidance-based fixed flattop operation mode (p < 0.01). Moreover, there was no significant difference in treatment time among the three technical combinations (p > 0.15). Conclusions The combination of the breathing guidance and PCR methods should be an alternative way for motion mitigation for the fixed flattop synchrotron operation mode. The target dose coverage and homogeneity could be further improved by the combination of the breathing guidance and PCR methods than the traditional PCR-only technology for the extended flattop synchrotron operation mode.
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Affiliation(s)
- Pengbo He
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Qiang Li,
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14
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Knopf AC, Czerska K, Fracchiolla F, Graeff C, Molinelli S, Rinaldi I, Rucincki A, Sterpin E, Stützer K, Trnkova P, Zhang Y, Chang JY, Giap H, Liu W, Schild SE, Simone CB, Lomax AJ, Meijers A. Clinical necessity of multi-image based (4DMIB) optimization for targets affected by respiratory motion and treated with scanned particle therapy – a comprehensive review. Radiother Oncol 2022; 169:77-85. [DOI: 10.1016/j.radonc.2022.02.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/31/2022] [Accepted: 02/14/2022] [Indexed: 12/28/2022]
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15
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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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16
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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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17
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Pastor-Serrano O, Habraken S, Lathouwers D, Hoogeman M, Schaart D, Perkó Z. How should we model and evaluate breathing interplay effects in IMPT? Phys Med Biol 2021; 66. [PMID: 34757958 DOI: 10.1088/1361-6560/ac383f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/10/2021] [Indexed: 11/12/2022]
Abstract
Breathing interplay effects in Intensity Modulated Proton Therapy (IMPT) arise from the interaction between target motion and the scanning beam. Assessing the detrimental effect of interplay and the clinical robustness of several mitigation techniques requires statistical evaluation procedures that take into account the variability of breathing during dose delivery. In this study, we present such a statistical method to model intra-fraction respiratory motion based on breathing signals and assess clinical relevant aspects related to the practical evaluation of interplay in IMPT such as how to model irregular breathing, how small breathing changes affect the final dose distribution, and what is the statistical power (number of different scenarios) required for trustworthy quantification of interplay effects. First, two data-driven methodologies to generate artificial patient-specific breathing signals are compared: a simple sinusoidal model, and a precise probabilistic deep learning model generating very realistic samples of patient breathing. Second, we investigate the highly fluctuating relationship between interplay doses and breathing parameters, showing that small changes in breathing period result in large local variations in the dose. Our results indicate that using a limited number of samples to calculate interplay statistics introduces a bigger error than using simple sinusoidal models based on patient parameters or disregarding breathing hysteresis during the evaluation. We illustrate the power of the presented statistical method by analyzing interplay robustness of 4DCT and Internal Target Volume (ITV) treatment plans for a 8 lung cancer patients, showing that, unlike 4DCT plans, even 33 fraction ITV plans systematically fail to fulfill robustness requirements.
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Affiliation(s)
- Oscar Pastor-Serrano
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Steven Habraken
- Erasmus MC Cancer Institute, University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Danny Lathouwers
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Mischa Hoogeman
- Erasmus MC Cancer Institute, University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Dennis Schaart
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands.,HollandPTC, Department of Radiation Oncology, Delft, The Netherlands
| | - Zoltán Perkó
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
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18
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Yoo GS, Yu JI, Park HC. Current role of proton beam therapy in patients with hepatocellular carcinoma. INTERNATIONAL JOURNAL OF GASTROINTESTINAL INTERVENTION 2021. [DOI: 10.18528/ijgii210043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Affiliation(s)
- Gyu Sang Yoo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jeong Il Yu
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hee Chul Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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19
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Worm ES, Hansen R, Høyer M, Weber B, Mortensen H, Poulsen PR. Uniform versus non-uniform dose prescription for proton stereotactic body radiotherapy of liver tumors investigated by extensive motion-including treatment simulations. Phys Med Biol 2021; 66. [PMID: 34544071 DOI: 10.1088/1361-6560/ac2880] [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: 04/08/2021] [Accepted: 09/20/2021] [Indexed: 12/24/2022]
Abstract
Compared to x-ray-based stereotactic body radiotherapy (SBRT) of liver cancer, proton SBRT may reduce the normal liver tissue dose. For an optimal trade-off between target and liver dose, a non-uniform dose prescription is often applied in x-ray SBRT, but lacks investigation for proton SBRT. Also, proton SBRT is prone to breathing-induced motion-uncertainties causing target mishit or dose alterations by interplay with the proton delivery. This study investigated non-uniform and uniform dose prescription in proton-based liver SBRT, including effects of rigid target motion observed during planning-4DCT and treatment. The study was based on 42 x-ray SBRT fractions delivered to 14 patients under electromagnetic motion-monitoring. For each patient, a non-uniform and uniform proton plan were made. The uniform plan was renormalized to be iso-toxic with the non-uniform plan using a NTCP model for radiation-induced liver disease. The motion data were used in treatment simulations to estimate the delivered target dose with rigid motion. Treatment simulations were performed with and without a repainting scheme designed to mitigate interplay effects. Including rigid motion, the achieved CTV mean dose after three fractions delivered without repainting was on average (±SD) 24.8 ± 8.4% higher and the D98%was 16.2 ± 11.3% higher for non-uniform plans than for uniform plans. The interplay-induced increase in D2%relative to the static plans was reduced from 3.2 ± 4.1% without repainting to -0.5 ± 1.7% with repainting for non-uniform plans and from 1.5 ± 2.0% to 0.1 ± 1.3% for uniform plans. Considerable differences were observed between estimated CTV doses based on 4DCT motion and intra-treatment motion. In conclusion, non-uniform dose prescription in proton SBRT may provide considerably higher tumor doses than uniform prescription for the same complication risk. Due to motion variability, target doses estimated from 4DCT motion may not accurately reflect the delivered dose. Future studies including modelling of deformations and associated range uncertainties are warranted to confirm the findings.
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Affiliation(s)
| | - Rune Hansen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Morten Høyer
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Britta Weber
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.,Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Hanna Mortensen
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Per Rugaard Poulsen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.,Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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20
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Emert F, Missimer J, Eichenberger PA, Walser M, Gmür C, Lomax AJ, Weber DC, Spengler CM. Enhanced Deep-Inspiration Breath Hold Superior to High-Frequency Percussive Ventilation for Respiratory Motion Mitigation: A Physiology-Driven, MRI-Guided Assessment Toward Optimized Lung Cancer Treatment With Proton Therapy. Front Oncol 2021; 11:621350. [PMID: 33996545 PMCID: PMC8116693 DOI: 10.3389/fonc.2021.621350] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/18/2021] [Indexed: 12/25/2022] Open
Abstract
Background: To safely treat lung tumors using particle radiation therapy (PRT), motion-mitigation strategies are of critical importance to ensure precise irradiation. Therefore, we compared applicability, effectiveness, reproducibility, and subjects' acceptance of enhanced deep-inspiration breath hold (eDIBH) with high-frequency percussive ventilation (HFPV) by MRI assessment within 1 month. Methods: Twenty-one healthy subjects (12 males/9 females; age: 49.5 ± 5.8 years; BMI: 24.7 ± 3.3 kg/m−2) performed two 1.5 T MRI scans in four visits at weekly intervals under eDIBH and HFPV conditions, accompanied by daily, home-based breath-hold training and spirometric assessments over a 3-week period. eDIBH consisted of 8-min 100% O2 breathing (3 min resting ventilation, 5 min controlled hyperventilation) prior to breath hold. HFPV was set at 200–250 pulses min−1 and 0.8–1.2 bar. Subjects' acceptance and preference were evaluated by questionnaire. To quantify inter- and intrafractional changes, a lung distance metric representing lung topography was computed for 10 reference points: a motion-invariant spinal cord and nine lung structure contours (LSCs: apex, carina, diaphragm, and six vessels as tumor surrogates distributed equally across the lung). To parameterize individual LSC localizability, measures of their spatial variabilities were introduced and lung volumes calculated by automated MRI analysis. Results: eDIBH increased breath-hold duration by > 100% up to 173 ± 73 s at visit 1, and to 217 ± 67 s after 3 weeks of home-based training at visit 4 (p < 0.001). Measures of vital capacity and lung volume remained constant over the 3-week period. Two vessels in the lower lung segment and the diaphragm yielded a two- to threefold improved positional stability with eDIBH, whereby absolute distance variability was significantly smaller for five LSCs; ≥70% of subjects showed significantly better intrafractional lung motion mitigation under reproducible conditions with eDIBH compared with HFPV with smaller ranges most apparent in the anterior-posterior and cranial-caudal directions. Approximately 80% of subjects preferred eDIBH over HFPV, with “less discomfort” named as most frequent reason. Conclusions: Both, eDIBH, and HFPV were well-tolerated. eDIBH duration was long enough to allow for potential PRT. Variability in lung volume was smaller and position of lung structures more precise with eDIBH. Subjects preferred eDIBH over HFPV. Thus, eDIBH is a very promising tool for lung tumor therapy with PRT, and further investigation of its applicability in patients is warranted.
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Affiliation(s)
- Frank Emert
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - John Missimer
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Philipp A Eichenberger
- Exercise Physiology Lab, Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Marc Walser
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Celina Gmür
- Exercise Physiology Lab, Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen, Switzerland.,Department of Physics, ETH Zurich, Zurich, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, Bern, Switzerland
| | - Christina M Spengler
- Exercise Physiology Lab, Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
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21
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Wan P, Chen F, Shao W, Liu C, Zhang Y, Wen B, Kong W, Zhang D. Irregular Respiratory Motion Compensation for Liver Contrast-Enhanced Ultrasound via Transport-Based Motion Estimation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:1117-1130. [PMID: 33108284 DOI: 10.1109/tuffc.2020.3033984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Contrast-enhanced ultrasound (CEUS) imaging has been widely applied for the detection and characterization of focal liver lesions (FLLs), for its ability to visualize the blood flow in real time. However, cyclic liver motion poses a great challenge to the recovery of perfusion curves as well as quantitative kinetic parameters estimation. Recently, a few gating methods have been proposed to eliminate unexpected intensity fluctuations by the breathing phase estimation, with the assumption that each breathing phase corresponds to a specific lesion position strictly. While practical liver motion tends to be irregular due to changes in the patient's underlying physiologic status, that is, the same phase might not correspond to the same position. To tackle the challenge of motion irregularity, we present a novel motion estimation-based respiratory compensation method, named RCME, which first estimates salient motion information through the framework of optimal transport (OT) by jointly modeling pixel intensity as well as their locations and then employs sparse subspace clustering (SSC) to identify the subset of frames acquired at the same position. Our proposed method is evaluated on 15 clinical CEUS sequences in both qualitative and quantitative manners. Experimental results demonstrate good performance on irregular liver motion compensation.
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Rana S, Rosenfeld AB. Investigating volumetric repainting to mitigate interplay effect on 4D robustly optimized lung cancer plans in pencil beam scanning proton therapy. J Appl Clin Med Phys 2021; 22:107-118. [PMID: 33599391 PMCID: PMC7984493 DOI: 10.1002/acm2.13183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/19/2021] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Purpose The interplay effect between dynamic pencil proton beams and motion of the lung tumor presents a challenge in treating lung cancer patients in pencil beam scanning (PBS) proton therapy. The main purpose of the current study was to investigate the interplay effect on the volumetric repainting lung plans with beam delivery in alternating order (“down” and “up” directions), and explore the number of volumetric repaintings needed to achieve acceptable lung cancer PBS proton plan. Method The current retrospective study included ten lung cancer patients. The total dose prescription to the clinical target volume (CTV) was 70 Gy(RBE) with a fractional dose of 2 Gy(RBE). All treatment plans were robustly optimized on all ten phases in the 4DCT data set. The Monte Carlo algorithm was used for the 4D robust optimization, as well as for the final dose calculation. The interplay effect was evaluated for both the nominal (i.e., without repainting) as well as volumetric repainting plans. The interplay evaluation was carried out for each of the ten different phases as the starting phases. Several dosimetric metrics were included to evaluate the worst‐case scenario (WCS) and bandwidth based on the results obtained from treatment delivery starting in ten different breathing phases. Results The number of repaintings needed to meet the criteria 1 (CR1) of target coverage (D95% ≥ 98% and D99% ≥ 97%) ranged from 2 to 10. The number of repaintings needed to meet the CR1 of maximum dose (ΔD1% < 1.5%) ranged from 2 to 7. Similarly, the number of repaintings needed to meet CR1 of homogeneity index (ΔHI < 0.03) ranged from 3 to 10. For the target coverage region, the number of repaintings needed to meet CR1 of bandwidth (<100 cGy) ranged from 3 to 10, whereas for the high‐dose region, the number of repaintings needed to meet CR1 of bandwidth (<100 cGy) ranged from 1 to 7. Based on the overall plan evaluation criteria proposed in the current study, acceptable plans were achieved for nine patients, whereas one patient had acceptable plan with a minor deviation. Conclusion The number of repaintings required to mitigate the interplay effect in PBS lung cancer (tumor motion < 15 mm) was found to be highly patient dependent. For the volumetric repainting with an alternating order, a patient‐specific interplay evaluation strategy must be adopted. Determining the optimal number of repaintings based on the bandwidth and WCS approach could mitigate the interplay effect in PBS lung cancer treatment.
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Affiliation(s)
- Suresh Rana
- Department of Medical PhysicsThe Oklahoma Proton CenterOklahoma CityOklahomaUSA
- Department of Radiation OncologyMiami Cancer InstituteBaptist Health South FloridaMiamiFLUSA
- Department of Radiation OncologyHerbert Wertheim College of MedicineFlorida International UniversityMiamiFLUSA
- Centre for Medical Radiation Physics (CMRP)University of WollongongWollongongNSWAustralia
| | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics (CMRP)University of WollongongWollongongNSWAustralia
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Zhang G, Wang J, Wang Y, Peng H. Proton FLASH: passive scattering or pencil beam scanning? Phys Med Biol 2021; 66:03NT01. [PMID: 33296881 DOI: 10.1088/1361-6560/abd22d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study focused on a direct comparison of dose delivery efficiency between two proton FLASH delivery modes: passive scattering and pencil beam scanning (PBS). Monte-Carlo simulation of the beamline was performed using the Geant4 package. Two proton energies (63 and 230 MeV) were selected, targeting for shallow and deep-seated tumors, respectively. Two irradiation field sizes were selected: 13 × 13 mm2 and 50 × 50 mm2. For each delivery mode, two cases were investigated: shoot-through and Bragg peak, yielding a total of 4 delivery scenarios. For the passive scattering mode, the impact on dose rate by multiple components along the beamline were investigated, including ridge-filter, scatterer, range shifter and collimator. A quantitative comparison among four scenarios was made in terms of field size, dose, dose rate and treatment plan quality (dose volume histogram). For the 230 MeV case, the dose rate (for 1 nA current) is 0.05 Gy s-1 (passive with Bragg peak, field size: 50 × 50 mm2) and 2.6 Gy s-1 (PBS with shoot-through). Dose rate comparison is made between passive scattering and PBS as the delivery changes from spot-layer to shoot-through. In conclusion, the study successfully established a benchmark reference for dose rate performance for different scenarios, taking into account components along the beamline, field size and beam current. The results allow us to predict and compare the required beam current to yield a dose rate sufficiently high, above the threshold of the FLASH effect.
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Affiliation(s)
- Guoliang Zhang
- Department of Medical Physics, Wuhan University, 430072, People's Republic of China
| | - Junliang Wang
- Cancer Radiation Therapy Center, Fifth Medical Center of Chinese PLA General Hospital, 100039, People's Republic of China
| | - Yuenan Wang
- Department of Radiation Oncology, Peking University Shenzhen Hospital, No. 1120, Lianhua Road, Futian District, Shenzhen, Guangdong Province, 518036, People's Republic of China
| | - Hao Peng
- Department of Medical Physics, Wuhan University, 430072, People's Republic of China.,NewRT Medical Systems Inc., Wuxi, 214144, People's Republic of China
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Krieger M, Giger A, Jud C, Duetschler A, Salomir R, Bieri O, Bauman G, Nguyen D, Cattin PC, Weber DC, Lomax AJ, Zhang Y. Liver-ultrasound-guided lung tumour tracking for scanned proton therapy: a feasibility study. Phys Med Biol 2021; 66:035011. [PMID: 33238246 DOI: 10.1088/1361-6560/abcde6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pencil beam scanned (PBS) proton therapy of lung tumours is hampered by respiratory motion and the motion-induced density changes along the beam path. In this simulation study, we aim to investigate the effectiveness of proton beam tracking for lung tumours both under ideal conditions and in conjunction with a respiratory motion model guided by real-time ultrasound imaging of the liver. Multiple-breathing-cycle 4DMRIs of the thorax and abdominal 2D ultrasound images were acquired simultaneously for five volunteers. Deformation vector fields extracted from the 4DMRI, referred to as ground truth motion, were used to generate 4DCT(MRI) data sets of two lung cancer patients, resulting in 10 data sets with variable motion patterns. Given the 4DCT(MRI) and the corresponding ultrasound images as surrogate data, a patient-specific motion model was built. The model consists of an autoregressive model and Gaussian process regression for the temporal and spatial prediction, respectively. Two-field PBS plans were optimised on the reference CTs, and 4D dose calculations (4DDC) were used to simulate dose delivery for (a) unmitigated motion, (b) ideal 2D and 3D tracking (both beam adaption and 4DDC based on ground truth motion), and (c) realistic 2D and 3D tracking (beam adaption based on motion predictions, 4DDC on ground truth motion). Model-guided tracking retrieved clinically acceptable target dose homogeneity, as seen in a substantial reduction of the D5%-D95% compared to the non-mitigated simulation. Tracking in 2D and 3D resulted in a similar improvement of the dose homogeneity, as did ideal and realistic tracking simulations. In some cases, however, the tracked deliveries resulted in a shift towards higher or lower dose levels, leading to unacceptable target over- or under-coverage. The presented motion modelling framework was shown to be an accurate motion prediction tool for the use in proton beam tracking. Tracking alone, however, may not always effectively mitigate motion effects, making it necessary to combine it with other techniques such as rescanning.
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Affiliation(s)
- Miriam Krieger
- Center for Proton Therapy, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland. Department of Physics, ETH Zurich, Zurich, Switzerland
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25
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Alina G, Krieger M, Jud C, Duetschler A, Salomir R, Bieri O, Bauman G, Nguyen D, Weber DC, Lomax AJ, Zhang Y, Cattin PC. Liver-ultrasound based motion modelling to estimate 4D dose distributions for lung tumours in scanned proton therapy. ACTA ACUST UNITED AC 2020; 65:235050. [DOI: 10.1088/1361-6560/abaa26] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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26
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Cozzi L, Comito T, Loi M, Fogliata A, Franzese C, Franceschini D, Clerici E, Reggiori G, Tomatis S, Scorsetti M. The Potential Role of Intensity-Modulated Proton Therapy in Hepatic Carcinoma in Mitigating the Risk of Dose De-Escalation. Technol Cancer Res Treat 2020; 19:1533033820980412. [PMID: 33287650 PMCID: PMC7727039 DOI: 10.1177/1533033820980412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE To investigate the role of intensity-modulated proton therapy (IMPT) for hepatocellular carcinoma (HCC) patients to be treated with stereotactic body radiation therapy (SBRT) in a risk-adapted dose prescription regimen. METHODS A cohort of 30 patients was retrospectively selected as "at-risk" of dose de-escalation due to the proximity of the target volumes to dose-limiting healthy structures. IMPT plans were compared to volumetric modulated arc therapy (VMAT) RapidArc (RA) plans. The maximum dose prescription foreseen was 75 Gy in 3 fractions. The dosimetric analysis was performed on several quantitative metrics on the target volumes and organs at risk to identify the relative improvement of IMPT over VMAT and to determine if IMPT could mitigate the need of dose reduction and quantify the consequent potential patient accrual rate for protons. RESULTS IMPT and VMAT plans resulted in equivalent target dose distributions: both could ensure the required coverage for CTV and PTV. Systematic and significant improvements were observed with IMPT for all organs at risk and metrics. An average gain of 9.0 ± 11.6, 8.5 ± 7.7, 5.9 ± 7.1, 4.2 ± 6.4, 8.9 ± 7.1, 6.7 ± 7.5 Gy was found in the near-to-maximum doses for the ribs, chest wall, heart, duodenum, stomach and bowel bag respectively. Twenty patients violated one or more binding constraints with RA, while only 2 with IMPT. For all these patients, some dose de-intensification would have been required to respect the constraints. For photons, the maximum allowed dose ranged from 15.0 to 20.63 Gy per fraction while for the 2 proton cases it would have been 18.75 or 20.63 Gy. CONCLUSION The results of this in-silico planning study suggests that IMPT might result in advantages compared to photon-based VMAT for HCC patients to be treated with ablative SBRT. In particular, the dosimetric characteristics of protons may avoid the need for dose de-escalation in a risk-adapted prescription regimen for those patients with lesions located in proximity of dose-limiting healthy structures. Depending on the selection thresholds, the number of patients eligible for treatment at the full dose can be significantly increased with protons.
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Affiliation(s)
- Luca Cozzi
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Milan-Rozzano, Italy
| | - Tiziana Comito
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Mauro Loi
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Antonella Fogliata
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Ciro Franzese
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Milan-Rozzano, Italy
| | - Davide Franceschini
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Elena Clerici
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Giacomo Reggiori
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Stefano Tomatis
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy
| | - Marta Scorsetti
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Milan-Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Milan-Rozzano, Italy
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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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Fracchiolla F, Dionisi F, Righetto R, Widesott L, Giacomelli I, Cartechini G, Farace P, Bertolini M, Amichetti M, Schwarz M. Clinical implementation of pencil beam scanning proton therapy for liver cancer with forced deep expiration breath hold. Radiother Oncol 2020; 154:137-144. [PMID: 32976870 DOI: 10.1016/j.radonc.2020.09.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 01/04/2023]
Abstract
PURPOSE To present our technique for liver cancer treatments with proton therapy in pencil beam scanning mode and to evaluate the impact of uncertainties on plan quality. MATERIALS AND METHODS Seventeen patients affected by liver cancer were included in this study. Patients were imaged and treated in forced breath-hold using the Active Breathing Coordinator system and monitored with an optical tracking system. Three simulation CTs were acquired to estimate the anatomical variability between breath-holds and generate an internal target volume (ITV). The treatment plans were optimized with a Single Field Optimization technique aimed at minimizing the use of range shifter. Plan robustness was tested simulating systematic range and setup uncertainties, as well as the interplay effect between breath-holds. The appropriateness of margin was further verified based on the actual positioning data acquired during treatment. RESULTS The dose distributions of the nominal plans achieved a satisfactory target coverage in 11 out of 17 patients, while in the remaining 6 D95 to the PTV was affected by the constraint on mean liver dose. The constraints for all other organs at risk were always within tolerances. The interplay effect had a limited impact on the dose distributions: the worst case scenario showed a D95 reduction in the ITV < 3.9 GyRBE and no OAR with D1 > 105% of the prescription dose. The robustness analysis showed that for 13 out of 17 patients the ITV coverage in terms of D95 was better than D95 of the PTV in the nominal plan. For the remaining 4 patients, the maximum difference between ITV D95 and PTV D95 was ≤0.7% even for the largest simulated setup error and it was deemed clinically acceptable. Hot spots in the OARs were always lower than 105% of the prescription dose. Positioning images confirmed that the breath hold technique and the PTV margin were adequate to compensate for inter- and intra-breath-hold variations in liver position. CONCLUSION We designed and clinically applied a technique for the treatment of liver cancer with proton pencil beam scanning in forced deep expiration breath-hold. The initial data on plan robustness and patient positioning suggest that the choices in terms of planning technique and treatment margins are able to reach the desired balance between target coverage and organ at risk sparing.
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Affiliation(s)
- Francesco Fracchiolla
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy.
| | - Francesco Dionisi
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Roberto Righetto
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Lamberto Widesott
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Irene Giacomelli
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | | | - Paolo Farace
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Mattia Bertolini
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Maurizio Amichetti
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Marco Schwarz
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy; TIFPA Trento Institute for Fundamental Physics and Applications, Italy
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Cozzi L, Vanderstraeten R, Fogliata A, Chang FL, Wang PM. The role of a knowledge based dose-volume histogram predictive model in the optimisation of intensity-modulated proton plans for hepatocellular carcinoma patients : Training and validation of a novel commercial system. Strahlenther Onkol 2020; 197:332-342. [PMID: 32676685 DOI: 10.1007/s00066-020-01664-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/29/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE To investigate the performance of a knowledge-based RapidPlan, for optimisation of intensity-modulated proton therapy (IMPT) plans applied to hepatocellular cancer (HCC) patients. METHODS A cohort of 65 patients was retrospectively selected: 50 were used to "train" the model, while the remaining 15 provided independent validation. The performance of the RapidPlan model was benchmarked against manual optimisation and was also compared to volumetric modulated arc therapy (RapidArc) photon plans. A subanalysis appraised the performance of the RapidPlan model applied to patients with lesions ≤300 cm3 or larger. Quantitative assessment was based on several metrics derived from the constraints of the NRG-GI003 clinical trial. RESULTS There was an equivalence between manual plans and RapidPlan-optimised IMPT plans, which outperformed the RapidArc plans. The planning dose-volume objectives were met on average for all structures except for D0.5 cm3 ≤30 Gy in the bowels. Limiting the results to the class-solution proton plans (all values in Gy), the data for manual plans vs RapidPlan-based IMPT plans, respectively, showed the following: D99% to the target of 47.5 ± 1.4 vs 47.2 ± 1.2; for organs at risk, the mean dose to the healthy liver was 6.7 ± 3.6 vs 6.7 ± 3.7; the mean dose to the kidneys was 0.2 ± 0.5 vs 0.1 ± 0.2; D0.5 cm3 for the bowels was 33.4 ± 16.4 vs 30.2 ± 16.0; for the stomach was 17.9 ± 19.9 vs 14.9 ± 18.8; for the oesophagus was 17.9 ± 15.1 vs 14.9 ± 13.9; for the spinal cord was 0.5 ± 1.6 vs 0.2 ± 0.7. The model performed similarly for cases with small or large lesions. CONCLUSION A knowledge-based RapidPlan model was trained and validated for IMPT. The results demonstrate that RapidPlan can be trained adequately for IMPT in HCC. The quality of the RapidPlan-based plans is at least equivalent compared to what is achievable with manual planning. RapidPlan also confirmed the potential to optimise the quality of the proton therapy results, thus reducing the impact of operator planning skills on patient results.
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Affiliation(s)
- Luca Cozzi
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Via Manzoni 56, 20089, Milan-Rozzano, Italy. .,Department of Biomedical Sciences, Humanitas University, Rozzano, Italy.
| | | | - Antonella Fogliata
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, IRCSS, Via Manzoni 56, 20089, Milan-Rozzano, Italy
| | - Feng-Ling Chang
- Radiation Oncology Department, Asian University Hospital, Taichung, Taiwan, Province of China
| | - Po-Ming Wang
- Radiation Oncology Department, Asian University Hospital, Taichung, Taiwan, Province of China
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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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Krieger M, Giger A, Salomir R, Bieri O, Celicanin Z, Cattin PC, Lomax AJ, Weber DC, Zhang Y. Impact of internal target volume definition for pencil beam scanned proton treatment planning in the presence of respiratory motion variability for lung cancer: A proof of concept. Radiother Oncol 2020; 145:154-161. [DOI: 10.1016/j.radonc.2019.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/15/2019] [Accepted: 12/03/2019] [Indexed: 11/25/2022]
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van de Water S, Safai S, Schippers JM, Weber DC, Lomax AJ. Towards FLASH proton therapy: the impact of treatment planning and machine characteristics on achievable dose rates. Acta Oncol 2019; 58:1463-1469. [PMID: 31241377 DOI: 10.1080/0284186x.2019.1627416] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background: This study aimed at evaluating spatially varying instantaneous dose rates for different intensity-modulated proton therapy (IMPT) planning strategies and delivery scenarios, and comparing these with FLASH dose rates (>40 Gy/s). Material and methods: In order to quantify dose rates in three-dimensions, we proposed the 'dose-averaged dose rate' (DADR) metric, defined for each voxel as the dose-weighted mean of the instantaneous dose rates of all spots (i.e., pencil beams). This concept was applied to four head-and-neck cases, each planned with clinical (4 fields) and various spot-reduced IMPT techniques: 'standard' (4 fields), 'arc' (120 fields) and 'arc-shoot-through' (120 fields; 229 MeV only). For all plans, different delivery scenarios were simulated: constant beam intensity, variable beam intensity for a clinical Varian ProBeam system, varied per energy layer or per spot, and theoretical spot-wise variable beam intensity (i.e., no monitor/safety limitations). DADR distributions were calculated assuming 2-Gy or 6-Gy fractions. Results: Spot-reduced plans contained 17-52 times fewer spots than clinical plans, with no deterioration of plan quality. For the clinical plans, the mean DADR in normal tissue for 2-Gy fractionation was 1.7 Gy/s (median over all patients) at maximum, whereas in standard spot-reduced plans it was 0.7, 4.4, 7.1, and 12.1 Gy/s, for the constant, energy-layer-wise, spot-wise, and theoretical spot-wise delivery scenarios, respectively. Similar values were observed for arc plans. Arc-shoot-through planning resulted in DADR values of 3.0, 6.0, 14.1, and 24.4 Gy/s, for the abovementioned scenarios. Hypofractionation (3×) generally resulted in higher dose rates, up to 73.2 Gy/s for arc-shoot-through plans. The DADR was inhomogeneously distributed with highest values at beam entrance and at the Bragg peak. Conclusion: FLASH dose rates were not achieved for conventional planning and clinical spot-scanning machines. As such, increased spot-wise beam intensities, spot-reduced planning, hypofractionation and arc-shoot-through plans were required to achieve FLASH compatible dose rates.
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Affiliation(s)
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Jacobus M. Schippers
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Therapy, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - Damien C. Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Oncology, University Hospital of Bern, Bern, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, Zürich, Switzerland
| | - Antony J. Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zürich, Zürich, Switzerland
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Raldow A, Lamb J, Hong T. Proton beam therapy for tumors of the upper abdomen. Br J Radiol 2019; 93:20190226. [PMID: 31430202 DOI: 10.1259/bjr.20190226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Proton radiotherapy has clear dosimetric advantages over photon radiotherapy. In contrast to photons, which are absorbed exponentially, protons have a finite range dependent on the initial proton energy. Protons therefore do not deposit dose beyond the tumor, resulting in great conformality, and offers the promise of dose escalation to increase tumor control while minimizing toxicity. In this review, we discuss the rationale for using proton radiotherapy in the treatment of upper abdominal tumors-hepatocellular carcinomas, cholangiocarcinomas and pancreatic cancers. We also review the clinical outcomes and technical challenges of using proton radiotherapy for the treatment of these malignancies. Finally, we discuss the ongoing clinical trials implementing proton radiotherapy for the treatment of primary liver and pancreatic tumors.
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Affiliation(s)
- Ann Raldow
- Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - James Lamb
- Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Theodore Hong
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA
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Zhang Y, Huth I, Weber DC, Lomax AJ. Dosimetric uncertainties as a result of temporal resolution in 4D dose calculations for PBS proton therapy. Phys Med Biol 2019; 64:125005. [PMID: 31035271 DOI: 10.1088/1361-6560/ab1d6f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This work investigates the dosimetric impact on 4D dose distribution estimation for pencil beam scanned (PBS) proton therapy as function of the temporal resolution used for the time resolved dose calculation. For three liver patients (CTV volume: 403/122/264 cc), 10-phase 4DCT-MRI datasets with ~15 mm tumour motion were simulated for seven different motion periods (2-8 s). 4D dose distributions were calculated and compared by considering both coarser and finer temporal resolutions (200-800 ms and 20 ms). Single scanned 4D plans for seven fraction doses (0.7/2/4/6/8/10/12 Gy) were investigated, whose dose delivery timelines were simulated by assuming two types of PBS scanning modes: (1) layer-wise raster scanning with varying dose rate per layer and (2) fixed dose rate, discrete scanning. For both delivery scenarios, dosimetric assessments were performed by comparing corresponding dose distributions derived from the two 4D dose calculation (4DDC) results. Differences were quantified as the difference in D5-D95 of the CTV and by comparing total volume of the CTV receiving point-to-point absolute dose difference more than 5%. Our results show that varying temporal resolution in 4DDC has a direct influence on the final accumulated dose distribution. For all scenarios, patients, fraction doses and motion periods studied, pronounced dose differences can be observed between the two 4DDC results. However, the magnitude of differences varies depending on the selected PBS scanning model and prescribed dose per field. For fixed dose rate delivery, the average duration of the delivery of each spot increases for hypo-fractionated treatments, enhancing the benefit of using a finer temporal resolution for 4DDC. In particular, for fraction doses >4 Gy and motion periods less than 4 s, warping the dose between discrete 4DCT phases can over predict the interplay effect (D5-D95 in CTV) by 3%-10% compared to the use of a finer temporal resolution, resulting in more than 20% of CTV voxels having absolute dose differences of over 5% between the two 4DDC approaches. These findings emphasize the importance for PBS 4DDC using finer temporal resolutions than provided by conventional 4D dose accumulation techniques. In particular, the observed differences in dosimetric effects using the fine temporal resolution provided by dose warping cannot be neglected for hypo-fractionation and short breathing periods, especially when using constant dose rates for dose delivery.
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Affiliation(s)
- Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institut, Villigen-PSI, Switzerland. Author to whom any correspondence should be addressed
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Dolde K, Schneider S, Stefanowicz S, Alimusaj M, Flügel B, Saito N, Troost EGC, Pfaffenberger A, Hoffmann AL. Comparison of pancreatic respiratory motion management with three abdominal corsets for particle radiation therapy: Case study. J Appl Clin Med Phys 2019; 20:111-119. [PMID: 31120639 PMCID: PMC6560237 DOI: 10.1002/acm2.12613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 01/10/2023] Open
Abstract
Background and purpose Abdominal organ motion seriously compromises the targeting accuracy for particle therapy in patients with pancreatic adenocarcinoma. This study compares three different abdominal corsets regarding their ability to reduce pancreatic motion and their potential usability in particle therapy. Materials and methods A patient‐individualized polyurethane (PU), a semi‐individualized polyethylene (PE), and a patient‐individualized three‐dimensional‐scan based polyethylene (3D‐PE) corset were manufactured for one healthy volunteer. Time‐resolved volumetric four‐dimensional‐magnetic resonance imaging (4D‐MRI) and single‐slice two‐dimensional (2D) cine‐MRI scans were acquired on two consecutive days to compare free‐breathing motion patterns with and without corsets. The corset material properties, such as thickness variance, material homogeneity in Hounsfield units (HU) on computed tomography (CT) scans, and manufacturing features were compared. The water equivalent ratio (WER) of corset material samples was measured using a multi‐layer ionization chamber for proton energies of 150 and 200 MeV. Results All corsets reduced the pancreatic motion on average by 9.6 mm in inferior–superior and by 3.2 mm in anterior‐posterior direction. With corset, the breathing frequency was approximately doubled and the day‐to‐day motion variations were reduced. The WER measurements showed an average value of 0.993 and 0.956 for the PE and 3DPE corset, respectively, and of 0.298 for the PU corset. The PE and 3DPE corsets showed a constant thickness of 2.8 ± 0.2 and 3.8 ± 0.2 mm, respectively and a homogeneous material composition with a standard deviation (SD) of 31 and 32 HU, respectively. The PU corset showed a variable thickness of 4.2 − 25.6 mm and a heterogeneous structure with air inclusions with an SD of 113 HU. Conclusion Abdominal corsets may be effective devices to reduce pancreatic motion. For particle therapy, PE‐based corsets are preferred over PU‐based corset due to their material homogeneity and constant thickness.
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Affiliation(s)
- Kai Dolde
- Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology, Heidelberg Institute for Radiooncology, Heidelberg, Germany.,Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Sergej Schneider
- Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Faculty of Medicine and University Hospital Carl Gustav Carus, OncoRay - National Center for Radiation Research in Oncology, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Sarah Stefanowicz
- Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Faculty of Medicine and University Hospital Carl Gustav Carus, OncoRay - National Center for Radiation Research in Oncology, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Merkur Alimusaj
- Center for Orthopedic and Trauma Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Beate Flügel
- Center for Orthopedic and Trauma Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Nami Saito
- Department of Radiation Oncology, University Clinic Heidelberg, Heidelberg, Germany
| | - Esther G C Troost
- Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Faculty of Medicine and 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 and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, and Helmholtz Association / Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden Germany
| | - Asja Pfaffenberger
- Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology, Heidelberg Institute for Radiooncology, Heidelberg, Germany
| | - Aswin L Hoffmann
- Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Faculty of Medicine and 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 and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Dolde K, Naumann P, Dávid C, Kachelriess M, Lomax AJ, Weber DC, Saito N, Burigo LN, Pfaffenberger A, Zhang Y. Comparing the effectiveness and efficiency of various gating approaches for PBS proton therapy of pancreatic cancer using 4D-MRI datasets. Phys Med Biol 2019; 64:085011. [PMID: 30893660 DOI: 10.1088/1361-6560/ab1175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Abdominal organ motion may lead to considerable uncertainties in pencil-beam scanning (PBS) proton therapy of pancreatic cancer. Beam gating, where irradiation only occurs in certain breathing phases in which the gating conditions are fulfilled, may be an option to reduce the interplay effect between tumor motion and the scanning beam. This study aims to, first, determine suitable gating windows with respect to effectiveness (low interplay effect) and efficiency (high duty cycles). Second, it investigates whether beam gating allows for a better mitigation of the interplay effect along the treatment course than free-breathing irradiations. Based on synthetic 4D-CTs, generated by warping 3D-CTs with vector fields extracted from time-resolved magnetic resonance imaging (4D-MRI) for 8 pancreatic cancer patients, 4D dose calculations (4DDC) were performed to analyze the duty cycle and homogeneity index HI = d5/d95 for four different gating scenarios. These were based on either fixed threshold values of CTV (clinical target volume) mean or maximum motion amplitudes (5 mm), relative CTV motion amplitudes (30%) or CTV overlap criteria (95%), respectively. 4DDC for 28-fractions treatment courses were performed with fixed and variable initial breathing phases to investigate the fractionation-induced mitigation of the interplay effect. Gating criteria, based on patient-specific relative 30% CTV motion amplitudes, showed the significantly best HI values with sufficient duty cycles, in contrast to inferior results by either fixed gating thresholds or overlap criteria. For gated treatments with 28 fractions, less fractionation-induced mitigation of the interplay effect was observed for gating criteria with gating windows ⩾30%, compared to free-breathing treatments. The gating effectiveness for multiple fractions was improved by allowing a variable initial breathing phase. Gating with relative amplitude thresholds are effective for proton therapy of pancreatic cancer. By combining beam gating with variable initial breathing phases, a pronounced mitigation of the interplay effect by fractionation can be achieved.
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Affiliation(s)
- Kai Dolde
- Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany. National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiooncology (HIRO), Heidelberg, Germany. Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany. Author to whom any correspondence should be addressed
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Winterhalter C, Zepter S, Shim S, Meier G, Bolsi A, Fredh A, Hrbacek J, Oxley D, Zhang Y, Weber DC, Lomax A, Safai S. Evaluation of the ray-casting analytical algorithm for pencil beam scanning proton therapy. Phys Med Biol 2019; 64:065021. [PMID: 30641496 DOI: 10.1088/1361-6560/aafe58] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
For pencil beam scanned (PBS) proton therapy, analytical dose calculation engines are still typically used for the optimisation process, and often for the final evaluation of the plan. Recently however, the suitability of analytical calculations for planning PBS treatments has been questioned. Conceptually, the two main approaches for these analytical dose calculations are the ray-casting (RC) and the pencil-beam (PB) method. In this study, we compare dose distributions and dosimetric indices, calculated on both the clinical dose calculation grid and as a function of dose grid resolution, to Monte Carlo (MC) calculations. The analysis is done using a comprehensive set of clinical plans which represent a wide choice of treatment sites. When analysing dose difference histograms for relative treatment plans, pencil beam calculations with double grid resolution perform best, with on average 97.7%/91.9% (RC), 97.9%/92.7% (RC, double grid resolution), 97.6%/91.0% (PB) and 98.6%/94.0% (PB, double grid resolution) of voxels agreeing within ±5%/± 3% between the analytical and the MC calculations. Even though these point-to-point dose comparison shows differences between analytical and MC calculations, for all algorithms, clinically relevant dosimetric indices agree within ±4% for the PTV and within ±5% for critical organs. While the clinical agreement depends on the treatment site, there is no substantial difference of indices between the different algorithms. The pencil-beam approach however comes at a higher computational cost than the ray-casting calculation. In conclusion, we would recommend using the ray-casting algorithm for fast dose optimization and subsequently combine it with one MC calculation to scale the absolute dose and assure the quality of the treatment plan.
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Affiliation(s)
- Carla Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland. Department of Physics, ETH Zurich, Zurich, Switzerland
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Effect of setup and inter-fraction anatomical changes on the accumulated dose in CT-guided breath-hold intensity modulated proton therapy of liver malignancies. Radiother Oncol 2019; 134:101-109. [PMID: 31005203 DOI: 10.1016/j.radonc.2019.01.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/04/2018] [Accepted: 01/22/2019] [Indexed: 12/13/2022]
Abstract
PURPOSE To evaluate the effect of setup uncertainties including uncertainties between different breath holds (BH) and inter-fractional anatomical changes under CT-guided BH with intensity-modulated proton therapy (IMPT) in patients with liver cancer. METHODS AND MATERIALS This retrospective study considered 17 patients with liver tumors who underwent feedback-guided BH (FGBH) IMRT treatment with daily CT-on-rail imaging. Planning CT images were acquired at simulation using FGBH, and FGBH CT-on-rail images were also acquired prior to each treatment. Selective robust IMPT plans were generated using planning CT and re-calculated on each daily CT-on-rail image. Subsequently, the fractional doses were deformed and accumulated onto the planning CT according to the deformable image registration between daily and planning CTs. The doses to the target and organs at risk (OARs) were compared between IMRT, planned IMPT, and accumulated IMPT doses. RESULTS For IMPT plans, the mean of D98% of CTV for all 17 patients was slightly reduced from the planned dose of 68.90 ± 1.61 Gy to 66.48 ± 1.67 Gy for the accumulated dose. The target coverage could be further improved by adjusting planning techniques. The dose-volume histograms of both planned and accumulated IMPT doses showed better sparing of OARs than that of the IMRT. CONCLUSIONS IMPT with FGBH and CT-on-rail guidance is a robust treatment approach for liver tumor cases.
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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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Cozzi L, Comito T, Fogliata A, Franzese C, Tomatis S, Scorsetti M. Critical appraisal of the potential role of intensity modulated proton therapy in the hypofractionated treatment of advanced hepatocellular carcinoma. PLoS One 2018; 13:e0201992. [PMID: 30102749 PMCID: PMC6089420 DOI: 10.1371/journal.pone.0201992] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/25/2018] [Indexed: 01/26/2023] Open
Abstract
PURPOSE To investigate the role of intensity modulated proton therapy (IMPT) for advanced hepatocellular carcinoma in comparison with volumetric modulated arc therapy (VMAT). METHODS An in-silico planning study was performed on 20 patients. The prescription dose was 60Gy in 6 fractions. Patients were planned with abdominal compression. IMPT plans were optimized with or without the inclusion of CT calibration (3%) and isocenter positioning (2,4,6mm) uncertainties. Plan robustness was appraised comparing rubust optimized plans vs standard plans and also in terms of the worst-case scenario. VMAT plans were optimized for 10FFF photon beams using 2 partial arcs. RESULTS Target coverage was fully achieved by both VMAT and IMPT plans with a significant improvement in homogeneity (~25%) with IMPT. Integral dose was reduced of ~60% with IMPT while the conformality of the dose distributions was similar among techniques. The sparing of the organs at risk was strongly improved with IMPT although all clinical objectives were met for both techniques. The inclusion of the uncertainties in the optimization lead to some deterioration in the target dose homogeneity (from 40 to 80% worse with 4 or 6mm position uncertainty) while none of the coverage parameters or OAR objective was violated. The worst-case scenario analysis demonstrated the risk of a major target underdosage only in the case of the most extreme errors (6mm) with D98% in average ~12% lower than the threshold. CONCLUSION IMPT with the support of abdominal compression, can be considered a viable solution also for advanced hepatocellular carcinoma patients. Great care shall be put in the minimization of the residual respiration and positioning uncertainties but the dosimetric advantage for organs at risk and the relative robustness on target coverage are promising factors.
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Affiliation(s)
- Luca Cozzi
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
- Humanitas University, Dept. of Biomedical Sciences, Milan-Rozzano, Italy
| | - Tiziana Comito
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
| | - Antonella Fogliata
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
| | - Ciro Franzese
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
| | - Stefano Tomatis
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
| | - Marta Scorsetti
- Humanitas Research Hospital and Cancer Center, Radiotherapy and Radiosurgery, Milan-Rozzano, Italy
- Humanitas University, Dept. of Biomedical Sciences, Milan-Rozzano, Italy
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Dolde K, Naumann P, Dávid C, Gnirs R, Kachelrieß M, Lomax AJ, Saito N, Weber DC, Pfaffenberger A, Zhang Y. 4D dose calculation for pencil beam scanning proton therapy of pancreatic cancer using repeated 4DMRI datasets. Phys Med Biol 2018; 63:165005. [PMID: 30020079 DOI: 10.1088/1361-6560/aad43f] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
4D magnetic resonance imaging (4DMRI) has a high potential for pancreatic cancer treatments using proton therapy, by providing time-resolved volumetric images with a high soft-tissue contrast without exposing the patient to any additional imaging dose. In this study, we aim to show the feasibility of 4D treatment planning for pencil beam scanning (PBS) proton therapy of pancreatic cancer, based on five repeated 4DMRI datasets and 4D dose calculations (4DDC) for one pancreatic cancer patient. To investigate the dosimetric impacts of organ motion, deformation vector fields were extracted from 4DMRI, which were then used to warp a static CT of the patient, so as to generate synthetic 4DCT (4DCT-MRI). CTV motion amplitudes <15 mm were observed for this patient. The results from 4DDC show pronounced interplay effects in the CTV with dose homogeneity d5/d95 and dose coverage v95 being 1.14 and 91%, respectively, after a single fraction of the treatment. An averaging effect was further observed when increasing the number of fractions. Motion effects can become less dominant and dose homogeneity d5/d95 = 1.03 and dose coverage v95 = [Formula: see text] within the CTV can be achieved after 28 fractions. The observed inter-fractional organ and tumor motion variations underline the importance of 4D imaging before and during PBS proton therapy.
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Affiliation(s)
- Kai Dolde
- Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany. National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiooncology (HIRO), Heidelberg, Germany. Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
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Yoo GS, Yu JI, Park HC. Proton therapy for hepatocellular carcinoma: Current knowledges and future perspectives. World J Gastroenterol 2018; 24:3090-3100. [PMID: 30065555 PMCID: PMC6064962 DOI: 10.3748/wjg.v24.i28.3090] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/28/2018] [Accepted: 06/25/2018] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy (RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy (PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.
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Affiliation(s)
- Gyu Sang Yoo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, South Korea
| | - Jeong Il Yu
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, South Korea
| | - Hee Chul Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, South Korea
- Department of Medical Device Management and Research, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 06351, South Korea
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Grau C, Baumann M, Weber DC. Optimizing clinical research and generating prospective high-quality data in particle therapy in Europe: Introducing the European Particle Therapy Network (EPTN). Radiother Oncol 2018; 128:1-3. [PMID: 30049367 DOI: 10.1016/j.radonc.2018.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/08/2018] [Accepted: 06/16/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Cai Grau
- The Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus C, Denmark.
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