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Lomax A. What will the medical physics of proton therapy look like 10 yr from now? A personal view. Med Phys 2018; 45:e984-e993. [DOI: 10.1002/mp.13206] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 07/29/2018] [Accepted: 08/31/2018] [Indexed: 11/06/2022] Open
Affiliation(s)
- Antony Lomax
- Centre for Proton Therapy Paul Scherrer Institute 5232 Villigen Aargau Switzerland
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102
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Graeff C, Bert C. Noninvasive cardiac arrhythmia ablation with particle beams. Med Phys 2018; 45:e1024-e1035. [DOI: 10.1002/mp.12595] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/05/2017] [Accepted: 09/17/2017] [Indexed: 12/31/2022] Open
Affiliation(s)
- Christian Graeff
- GSI Helmholzzentrum für Schwerionenforschung GmbH 64291 Darmstadt Germany
| | - Christoph Bert
- Department of Radiation Oncology Universitätsklinikum Erlangen Friedrich‐Alexander‐Universität 91054 Erlangen‐Nürnberg Germany
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Kurz C, Süss P, Arnsmeyer C, Haehnle J, Teichert K, Landry G, Hofmaier J, Exner F, Hille L, Kamp F, Thieke C, Ganswindt U, Valentini C, Hölscher T, Troost E, Krause M, Belka C, Küfer KH, Parodi K, Richter C. Dose-guided patient positioning in proton radiotherapy using multicriteria-optimization. Z Med Phys 2018; 29:216-228. [PMID: 30409729 DOI: 10.1016/j.zemedi.2018.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 10/01/2018] [Accepted: 10/15/2018] [Indexed: 12/25/2022]
Abstract
Proton radiotherapy (PT) requires accurate target alignment before each treatment fraction, ideally utilizing 3D in-room X-ray computed tomography (CT) imaging. Typically, the optimal patient position is determined based on anatomical landmarks or implanted markers. In the presence of non-rigid anatomical changes, however, the planning scenario cannot be exactly reproduced and positioning should rather aim at finding the optimal position in terms of the actually applied dose. In this work, dose-guided patient alignment, implemented as multicriterial optimization (MCO) problem, was investigated in the scope of intensity-modulated and double-scattered PT (IMPT and DSPT) for the first time. A method for automatically determining the optimal patient position with respect to pre-defined clinical goals was implemented. Linear dose interpolation was used to access a continuous space of potential patient shifts. Fourteen head and neck (H&N) and eight prostate cancer patients with up to five repeated CTs were included. Dose interpolation accuracy was evaluated and the potential dosimetric advantages of dose-guided over bony-anatomy-based patient alignment investigated by comparison of clinically relevant target and organ-at-risk (OAR) dose-volume histogram (DVH) parameters. Dose interpolation was found sufficiently accurate with average pass-rates of 90% and 99% for an exemplary H&N and prostate patient, respectively, using a 2% dose-difference criterion. Compared to bony-anatomy-based alignment, the main impact of automated MCO-based dose-guided positioning was a reduced dose to the serial OARs (spinal cord and brain stem) for the H&N cohort. For the prostate cohort, under-dosage of the target structures could be efficiently diminished. Limitations of dose-guided positioning were mainly found in reducing target over-dosage due to weight loss for H&N patients, which might require adaptation of the treatment plan. Since labor-intense online quality-assurance is not required for dose-guided patient positioning, it might, nevertheless, be considered an interesting alternative to full online re-planning for initially mitigating the effects of anatomical changes.
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Affiliation(s)
- Christopher Kurz
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany; Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany.
| | - Philipp Süss
- Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany
| | - Carolin Arnsmeyer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Fetscherstr. 74, PF 41, 01307 Dresden, Germany
| | - Jonas Haehnle
- Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany
| | - Katrin Teichert
- Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany
| | - Guillaume Landry
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - Jan Hofmaier
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany
| | - Florian Exner
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Fetscherstr. 74, PF 41, 01307 Dresden, Germany
| | - Lucas Hille
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - Florian Kamp
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany
| | - Christian Thieke
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany
| | - Ute Ganswindt
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany
| | - Chiara Valentini
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Tobias Hölscher
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Esther Troost
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Fetscherstr. 74, PF 41, 01307 Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; German Cancer Consortium (DKTK) partner site Dresden, Germany and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Bautzner Landstr. 400, 01328 Dresden, Germany; National Center for Tumor Diseases (NCT), partner site Dresden, Germany
| | - Mechthild Krause
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Fetscherstr. 74, PF 41, 01307 Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; German Cancer Consortium (DKTK) partner site Dresden, Germany and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Bautzner Landstr. 400, 01328 Dresden, Germany; National Center for Tumor Diseases (NCT), partner site Dresden, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377 München, Germany; German Cancer Consortium (DKTK) partner site Munich, Germany and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Karl-Heinz Küfer
- Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - 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, Fetscherstr. 74, PF 41, 01307 Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; German Cancer Consortium (DKTK) partner site Dresden, Germany and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Bautzner Landstr. 400, 01328 Dresden, Germany
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Pepin MD, Tryggestad E, Wan Chan Tseung HS, Johnson JE, Herman MG, Beltran C. A Monte-Carlo-based and GPU-accelerated 4D-dose calculator for a pencil beam scanning proton therapy system. Med Phys 2018; 45:5293-5304. [PMID: 30203550 DOI: 10.1002/mp.13182] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/30/2018] [Accepted: 08/31/2018] [Indexed: 01/16/2023] Open
Abstract
PURPOSE The presence of respiratory motion during radiation treatment leads to degradation of the expected dose distribution, both for target coverage and healthy tissue sparing, particularly for techniques like pencil beam scanning proton therapy which have dynamic delivery systems. While tools exist to estimate this degraded four-dimensional (4D) dose, they typically have one or more deficiencies such as not including the particular effects from a dynamic delivery, using analytical dose calculations, and/or using nonphysical dose-accumulation methods. This work presents a clinically useful 4D-dose calculator that addresses each of these shortcomings. METHODS To quickly compute the 4D dose, the three main tasks of the calculator were run on graphics processing units (GPUs). These tasks were (a) simulating the delivery of the plan using measured delivery parameters to distribute the plan amongst 4DCT phases characterizing the patient breathing, (b) using an in-house Monte Carlo simulation (MC) dose calculator to determine the dose delivered to each breathing phase, and (c) accumulating the doses from the various breathing phases onto a single phase for evaluation. The accumulation was performed by individually transferring the energy and mass of dose-grid subvoxels, a technique that models the transfer of dose in a more physically realistic manner. The calculator was run on three test cases, with lung, esophagus, and liver targets, respectively, to assess the various uncertainties in the beam delivery simulation as well as to characterize the dose-accumulation technique. RESULTS Four-dimensional doses were successfully computed for the three test cases with computation times ranging from 4-6 min on a server with eight NVIDIA Titan X graphics cards; the most time-consuming component was the MC dose engine. The subvoxel-based dose-accumulation technique produced stable 4D-dose distributions at subvoxel scales of 0.5-1.0 mm without impairing the total computation time. The uncertainties in the beam delivery simulation led to moderate variations of the dose-volume histograms for these cases; the variations were reduced by implementing repainting or phase-gating motion mitigation techniques in the calculator. CONCLUSIONS A MC-based and GPU-accelerated 4D-dose calculator was developed to estimate the effects of respiratory motion on pencil beam scanning proton therapy treatments. After future validation, the calculator could be used to assess treatment plans and its quick runtime would make it easily usable in a future 4D-robust optimization system.
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Affiliation(s)
- Mark D Pepin
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Erik Tryggestad
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Hok Seum Wan Chan Tseung
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Jedediah E Johnson
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Michael G Herman
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
| | - Chris Beltran
- Department of Radiation Oncology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN, 55905, USA
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105
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Mondlane G, Ureba A, Gubanski M, Lind PA, Siegbahn A. Estimation of the risk for radiation-induced liver disease following photon- or proton-beam radiosurgery of liver metastases. Radiat Oncol 2018; 13:206. [PMID: 30348194 PMCID: PMC6196431 DOI: 10.1186/s13014-018-1151-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/04/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Radiotherapy of liver metastases is commonly being performed with photon-beam based stereotactic body radiation therapy (SBRT). The high risk for radiation-induced liver disease (RILD) is a limiting factor in these treatments. The use of proton-beam based SBRT could potentially improve the sparing of the healthy part of the liver. The aim of this study was to use estimations of normal tissue complication probability (NTCP) to identify liver-metastases patients that could benefit from being treated with intensity-modulated proton therapy (IMPT), based on the reduction of the risk for RILD. METHODS Ten liver metastases patients, previously treated with photon-beam based SBRT, were retrospectively planned with IMPT. A CTV-based robust optimisation (accounting for setup and range uncertainties), combined with a PTV-based conventional optimisation, was performed. A robustness criterion was defined for the CTV (V95% > 98% for at least 10 of the 12 simulated scenarios). The NTCP was estimated for different endpoints using the Lyman-Kutcher-Burman model. The ΔNTCP (NTCPIMPT - NTCPSBRT) for RILD was registered for each patient. The patients for which the NTCP (RILD) < 5% were also identified. A generic relative biological effectiveness of 1.1 was assumed for the proton beams. RESULTS For all patients, the objectives set for the PTV and the robustness criterion set for the CTV were fulfilled with the IMPT plans. An improved sparing of the healthy part of the liver, right kidney, lungs, spinal cord and the skin was achieved with the IMPT plans, compared to the SBRT plans. Mean liver doses larger than the threshold value of 32 Gy led to NTCP values for RILD exceeding 5% (7 patients with SBRT and 3 patients with the IMPT plans). ΔNTCP values (RILD) ranging between - 98% and - 17% (7 patients) and between 0 and 2% (3 patients), were calculated. CONCLUSIONS In this study, liver metastases patients that could benefit from being treated with IMPT, based on the NTCP reductions, were identified. The clinical implementation of such a model-based approach to select liver metastases patients to proton therapy needs to be made with caution while considering the uncertainties involved in the NTCP estimations.
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Affiliation(s)
- Gracinda Mondlane
- Department of Physics – Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Physics, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Ana Ureba
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Michael Gubanski
- Department of Oncology and Pathology, Karolinska University Hospital, Stockholm, Sweden
| | - P A Lind
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Oncology, Södersjukhuset, Stockholm, Sweden
| | - Albert Siegbahn
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Oncology, Södersjukhuset, Stockholm, Sweden
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106
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Vogin G, Wambersie A, Pötter R, Beuve M, Combs SE, Magrin G, Mayer R, Mock U, Sarrut D, Schreiner T, Fossati P, Balosso J. Concepts and terms for dose/volume parameters in carbon-ion radiotherapy: Conclusions of the ULICE taskforce. Cancer Radiother 2018; 22:802-809. [PMID: 30327228 DOI: 10.1016/j.canrad.2017.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/24/2017] [Accepted: 11/29/2017] [Indexed: 01/24/2023]
Abstract
PURPOSE The Union of Light Ion Centers in Europe (ULICE) program addressed the need for uniting scientific results for carbon-ion radiation therapy obtained by several institutions worldwide in different fields of excellence, and translating them into a real benefit to the community. Particularly, the concepts for dose/volume parameters developed in photon radiotherapy cannot be extrapolated to high linear energy transfer particles. METHODS AND MATERIALS The ULICE-WP2 taskforce included radiation oncologists involved in carbon-ion radiation therapy and International Commission on Radiation Units and Measurements, radiation biologists, expert physicists in the fields of carbon-ion radiation therapy, microdosimetry, biological modeling and image-guided radiotherapy. Consensual reports emerged from multiple discussions within both the restricted group and the wider ULICE community. Public deliverables were produced and disseminated to the European Commission. RESULTS Here we highlight the disparity in practices between treating centers, then address the main topics to finally elaborate specific recommendations. Although it appears relatively simple to add geometrical margins around the clinical target volume to obtain the planning target volume as performed in photon radiotherapy, this procedure is not appropriate for carbon-ion radiation therapy. Due to the variation of the radiation quality in depth, there is no generic relative biological effectiveness value for carbon-ions outside of an isolated point, for a given fractionation and specific experimental conditions. Absorbed dose and "equieffective dose" for specified conditions must always be reported. CONCLUSIONS This work contributed to the development of standard operating procedures for carbon-ion radiation therapy clinical trials. These procedures are now being applied, particularly in the first phase III international, multicenter trial (PHRC Étoile).
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Affiliation(s)
- G Vogin
- Département de radiothérapie, institut de cancérologie de Lorraine Alexis-Vautrin, 54519 Vandœuvre-lès-Nancy cedex, France; CNRS, UMR 7365, ingénierie moléculaire et physiopathologie articulaire (Imopa), 54505 Vandœuvre-lès-Nancy cedex, France; Université de Lorraine, 54505 Vandoeuvre-lès-Nancy, France.
| | - A Wambersie
- Institut de recherche expérimentale et clinique (Irec), Molecular Imaging, Radiotherapy and Oncology (MIRO), cliniques universitaires Saint-Luc, 1200 Brussels, Belgium; Université catholique de Louvain (UCL), 1348 Louvain-la-Neuve, Belgium
| | - R Pötter
- Department of Radiotherapy, Comprehensive Cancer Center, Vienna, Austria; Medical University of Vienna, Vienna, Austria
| | - M Beuve
- Université Lyon 1, 69100 Villeurbanne, France; Institut de physique nucléaire de Lyon, 69622 Villeurbanne cedex, France
| | - S E Combs
- Klinik und Poliklinik für RadioOnkologie und Strahlentherapie, Technische Universität München (TUM), 81675 München, Germany; Instituts für Innovative Radiotherapie (iRT), Helmholtz Zentrum München, 85764 Oberschleißheim, Germany
| | - G Magrin
- EBG MedAustron GmbH, 2700 Wiener-Neustadt, Austria
| | - R Mayer
- EBG MedAustron GmbH, 2700 Wiener-Neustadt, Austria
| | - U Mock
- EBG MedAustron GmbH, 2700 Wiener-Neustadt, Austria
| | - D Sarrut
- Université Lyon 1, 69100 Villeurbanne, France; CNRS, UMR 5220 Laboratoire Creatis, 69100 Villeurbanne, France; Inserm, U1044 Laboratoire Creatis, 69100 Villeurbanne, France
| | - T Schreiner
- EBG MedAustron GmbH, 2700 Wiener-Neustadt, Austria
| | - P Fossati
- Università di Milano-Medicina e Chirurgia, Milano, Italy; Fondazione CNAO (Centro Nazionale di Adroterapia Oncologica), Pavia, Italy
| | - J Balosso
- Service de cancérologie-radiothérapie, hôpital Albert-Michallon, CHU Grenoble Alpes, 38043 Grenoble cedex 09, France; IPNL, France Hadron national research infrastructure, 69000 Lyon, France; Université Grenoble Alpes, 38400 Saint-Martin-d'Hères, France
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Fast robust dose calculation on GPU for high-precision 1H, 4He, 12C and 16O ion therapy: the FRoG platform. Sci Rep 2018; 8:14829. [PMID: 30287930 PMCID: PMC6172246 DOI: 10.1038/s41598-018-33194-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022] Open
Abstract
Radiotherapy with protons and heavier ions landmarks a novel era in the field of high-precision cancer therapy. To identify patients most benefiting from this technologically demanding therapy, fast assessment of comparative treatment plans utilizing different ion species is urgently needed. Moreover, to overcome uncertainties of actual in-vivo physical dose distribution and biological effects elicited by different radiation qualities, development of a reliable high-throughput algorithm is required. To this end, we engineered a unique graphics processing unit (GPU) based software architecture allowing rapid and robust dose calculation. FRoG, Fast Recalculation on GPU, currently operates with four particle beams available at Heidelberg Ion Beam Therapy center, i.e., raster-scanning proton (1H), helium (4He), carbon (12C) and oxygen ions (16O). FRoG enables comparative analysis of different models for estimation of physical and biological effective dose in 3D within minutes and in excellent agreement with the gold standard Monte Carlo (MC) simulation. This is a crucial step towards development of next-generation patient specific radiotherapy.
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Karani N, Tanner C, Kozerke S, Konukoglu E. Reducing Navigators in Free-Breathing Abdominal MRI via Temporal Interpolation Using Convolutional Neural Networks. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:2333-2343. [PMID: 29994024 DOI: 10.1109/tmi.2018.2831442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Navigated 2-D multi-slice dynamic magnetic resonance imaging (MRI) acquisitions are essential for MR guided therapies. This technique yields time-resolved volumetric images during free-breathing, which are ideal for visualizing and quantifying breathing induced motion. To achieve this, navigated dynamic imaging requires acquiring multiple navigator slices. Reducing the number of navigator slices would allow for acquiring more data slices in the same time, and hence, increasing through-plane resolution or alternatively the overall acquisition time can be reduced while keeping resolution unchanged. To this end, we propose temporal interpolation of navigator slices using convolutional neural networks (CNNs). Our goal is to acquire fewer navigators and replace the missing ones with interpolation. We evaluate the proposed method on abdominal navigated dynamic MRI sequences acquired from 14 subjects. Investigations with several CNN architectures and training loss functions show favorable results for cost and a simple feed-forward network with no skip connections. When compared with interpolation by non-linear registration, the proposed method achieves higher interpolation accuracy on average as quantified in terms of root mean square error and residual motion. Analysis of the differences shows that the better performance is due to more accurate interpolation at peak exhalation and inhalation positions. Furthermore, the CNN-based approach requires substantially lower execution times than that of the registration-based method. At last, experiments on dynamic volume reconstruction reveal minimal differences between reconstructions with acquired and interpolated navigator slices.
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Fullerenol C60(OH)36 protects human erythrocyte membrane against high-energy electrons. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1528-1536. [DOI: 10.1016/j.bbamem.2018.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/29/2022]
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Giger A, Stadelmann M, Preiswerk F, Jud C, De Luca V, Celicanin Z, Bieri O, Salomir R, Cattin PC. Ultrasound-driven 4D MRI. Phys Med Biol 2018; 63:145015. [PMID: 29864021 DOI: 10.1088/1361-6560/aaca1d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present an ultrasound-driven 4D magnetic resonance imaging (US-4DMRI) method for respiratory motion imaging in the thorax and abdomen. The proposed US-4DMRI comes along with a high temporal resolution, and allows for organ motion imaging beyond a single respiratory cycle. With the availability of the US surrogate both inside and outside the MR bore, 4D MR images can be reconstructed for 4D treatment planning and online respiratory motion prediction during radiotherapy. US-4DMRI relies on simultaneously acquired 2D liver US images and abdominal 2D MR multi-slice scans under free respiration. MR volumes are retrospectively composed by grouping the MR slices corresponding to the most similar US images. We present two different US similarity metrics: an intensity-based approach, and a similarity measure relying on predefined fiducials which are being tracked over time. The proposed method is demonstrated on MR liver scans of eight volunteers acquired over a duration of 5.5 min each at a temporal resolution of 2.6 Hz with synchronous US imaging at 14 Hz-17 Hz. Visual inspection of the reconstructed MR volumes revealed satisfactory results in terms of continuity in organ boundaries and blood vessels. In quantitative leave-one-out experiments, both US similarity metrics reach the performance level of state-of-the-art navigator-based approaches.
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Affiliation(s)
- Alina Giger
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland. Center for Medical Image Analysis & Navigation, University of Basel, Allschwil, Switzerland
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Engwall E, Fredriksson A, Glimelius L. 4D robust optimization including uncertainties in time structures can reduce the interplay effect in proton pencil beam scanning radiation therapy. Med Phys 2018; 45:4020-4029. [PMID: 30014478 DOI: 10.1002/mp.13094] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 07/04/2018] [Accepted: 07/04/2018] [Indexed: 02/28/2024] Open
Abstract
PURPOSE Interplay effects in proton radiotherapy can create large distortions in the dose distribution and severely degrade the plan quality. Standard methods to mitigate these effects include abdominal compression, gating, and rescanning. We propose a new method to include the time structures of the delivery and organ motion in the framework of four-dimensional (4D) robust optimization to generate plans that are robust against interplay effects. METHODS The method considers multiple scenarios reflecting the uncertainties in the delivery and in the organ motion. In each scenario, the pencil beam scanning spots are distributed to different phases of the breathing cycle according to each individual spot time stamp, and a partial beam dose is calculated for each phase. The partial beam doses are accumulated on a reference phase through deformable image registrations. Minimax optimization is performed to take all scenarios into account simultaneously. For simplicity, the uncertainties in this proof of concept study are limited to variations in the breathing pattern. The method is evaluated for three different nonsmall cell lung cancer patients and compared to plans using conventional 4D robust optimization both with and without rescanning. We assess the ability of the method to mitigate distortions from the interplay effect over multiple evaluation scenarios using 4D dose calculations. This interplay evaluation is performed in an experimentally validated framework, which is independent of the optimization in the plan generation step. RESULTS For the three studied patients, 4D optimization including time structures is efficient, especially for large tumor motions, where rescanning of conventional 4D robustly optimized plans is not sufficient to mitigate the interplay effect. The most efficient approach of the new method is achieved when it is combined with rescanning. For the patient with the largest motion, the mean V95% is 99.2% and mean V107% is 3.65% for the best rescanned 4D plan optimized with time structure. This can be compared to conventional 4D optimized plans with mean V95% of 92.7% and mean V107% of 13.1%. CONCLUSIONS The current study shows the potential of reducing interplay effects in proton pencil beam scanning radiotherapy by incorporating organ motion and delivery characteristics in a 4D robust optimization.
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Affiliation(s)
- Erik Engwall
- RaySearch Laboratories, Sveavägen 44, Stockholm, SE-111 34, Sweden
| | | | - Lars Glimelius
- RaySearch Laboratories, Sveavägen 44, Stockholm, SE-111 34, Sweden
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Klimpki G, Zhang Y, Fattori G, Psoroulas S, Weber DC, Lomax A, Meer D. The impact of pencil beam scanning techniques on the effectiveness and efficiency of rescanning moving targets. ACTA ACUST UNITED AC 2018; 63:145006. [DOI: 10.1088/1361-6560/aacd27] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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113
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Batista V, Richter D, Chaudhri N, Naumann P, Herfarth K, Jäkel O. Significance of intra-fractional motion for pancreatic patients treated with charged particles. Radiat Oncol 2018; 13:120. [PMID: 29941049 PMCID: PMC6020245 DOI: 10.1186/s13014-018-1060-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 06/13/2018] [Indexed: 12/30/2022] Open
Abstract
Background Uncertainties associated with the delivery of treatment to moving organs might compromise the accuracy of treatment. This study explores the impact of intra-fractional anatomical changes in pancreatic patients treated with charged particles delivered using a scanning beam. The aim of this paper is to define the potential source of uncertainties, quantify their effect, and to define clinically feasible strategies to reduce them. Methods The study included 14 patients treated at our facility with charged particles (protons or 12C) using intensity modulated particle therapy (IMPT). Treatment plans were optimized using the Treatment Planning System (TPS) Syngo® RT Planning. The pre-treatment dose distribution under motion (4D) was simulated using the TPS TRiP4D and the dose delivered for some of the treatment fractions was reconstructed. The volume receiving at least 95% of the prescribed dose (V95CTV) and the target dose homogeneity were evaluated. The results from the 4D dose calculations were compared with dose distributions in the static case and its variation correlated with the internal motion amplitude and plan modulation, through the Pearson correlation coefficient, as well the significant p-value. The concept of the modulation index (MI) was introduced to assess the degree of modulation of IMPT plans, through the quantification of intensity gradients between neighboring pencil beams. Results The induced breathing motion together with dynamic beam delivery results in an interplay effect, which affects the homogeneity and target coverage of the dose distribution. This effect is stronger (∆V95CTV > 10%) for patients with tumor motion amplitude above 5 mm and a highly modulated dose distribution between and within fields. The MI combined with the internal motion amplitude is shown to correlate with the target dose degradation and a lack of plan robustness against range and positioning uncertainties. Conclusions Under internal motion the use of inhomogeneous plans results in a decrease in the dose homogeneity and target coverage of dose distributions in comparison to the static case. Plan robustness can be improved by using multiple beams and avoiding beam entrance directions susceptible to density changes. 4D dose calculations support the selection of the most suitable plan for the specific patient’s anatomy. Electronic supplementary material The online version of this article (10.1186/s13014-018-1060-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vania Batista
- Heidelberg University Hospital, Heidelberg, Germany. .,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany. .,RadioOnkologie und Strahlentherapie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| | - Daniel Richter
- Erlangen University Hospital, Erlangen, Germany.,GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Naved Chaudhri
- Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Patrick Naumann
- Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Klaus Herfarth
- Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
| | - Oliver Jäkel
- Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany.,German Cancer Research Center, Div. Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120, Heidelberg, Germany
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114
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Engwall E, Glimelius L, Hynning E. Effectiveness of different rescanning techniques for scanned proton radiotherapy in lung cancer patients. Phys Med Biol 2018; 63:095006. [PMID: 29616984 DOI: 10.1088/1361-6560/aabb7b] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Non-small cell lung cancer (NSCLC) is a tumour type thought to be well-suited for proton radiotherapy. However, the lung region poses many problems related to organ motion and can for actively scanned beams induce severe interplay effects. In this study we investigate four mitigating rescanning techniques: (1) volumetric rescanning, (2) layered rescanning, (3) breath-sampled (BS) layered rescanning, and (4) continuous breath-sampled (CBS) layered rescanning. The breath-sampled methods will spread the layer rescans over a full breathing cycle, resulting in an improved averaging effect at the expense of longer treatment times. In CBS, we aim at further improving the averaging by delivering as many rescans as possible within one breathing cycle. The interplay effect was evaluated for 4D robustly optimized treatment plans (with and without rescanning) for seven NSCLC patients in the treatment planning system RayStation. The optimization and final dose calculation used a Monte Carlo dose engine to account for the density heterogeneities in the lung region. A realistic treatment delivery time structure given from the IBA ScanAlgo simulation tool served as basis for the interplay evaluation. Both slow (2.0 s) and fast (0.1 s) energy switching times were simulated. For all seven studied patients, rescanning improves the dose conformity to the target. The general trend is that the breath-sampled techniques are superior to layered and volumetric rescanning with respect to both target coverage and variability in dose to OARs. The spacing between rescans in our breath-sampled techniques is set at planning, based on the average breathing cycle length obtained in conjunction with CT acquisition. For moderately varied breathing cycle lengths between planning and delivery (up to 15%), the breath-sampled techniques still mitigate the interplay effect well. This shows the potential for smooth implementation at the clinic without additional motion monitoring equipment.
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Affiliation(s)
- E Engwall
- RaySearch Laboratories AB, Stockholm, Sweden
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115
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Mohamad O, Yamada S, Durante M. Clinical Indications for Carbon Ion Radiotherapy. Clin Oncol (R Coll Radiol) 2018; 30:317-329. [DOI: 10.1016/j.clon.2018.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 11/20/2017] [Indexed: 12/16/2022]
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116
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Bolwin K, Czekalla B, Frohwein LJ, Büther F, Schäfers KP. Anthropomorphic thorax phantom for cardio-respiratory motion simulation in tomographic imaging. Phys Med Biol 2018; 63:035009. [DOI: 10.1088/1361-6560/aaa201] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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117
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Pfeiler T, Bäumer C, Engwall E, Geismar D, Spaan B, Timmermann B. Experimental validation of a 4D dose calculation routine for pencil beam scanning proton therapy. Z Med Phys 2018; 28:121-133. [DOI: 10.1016/j.zemedi.2017.07.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/12/2017] [Accepted: 07/25/2017] [Indexed: 12/15/2022]
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118
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Mohamad O, Makishima H, Kamada T. Evolution of Carbon Ion Radiotherapy at the National Institute of Radiological Sciences in Japan. Cancers (Basel) 2018; 10:cancers10030066. [PMID: 29509684 PMCID: PMC5876641 DOI: 10.3390/cancers10030066] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 03/02/2018] [Accepted: 03/02/2018] [Indexed: 12/19/2022] Open
Abstract
Charged particles can achieve better dose distribution and higher biological effectiveness compared to photon radiotherapy. Carbon ions are considered an optimal candidate for cancer treatment using particles. The National Institute of Radiological Sciences (NIRS) in Chiba, Japan was the first radiotherapy hospital dedicated for carbon ion treatments in the world. Since its establishment in 1994, the NIRS has pioneered this therapy with more than 69 clinical trials so far, and hundreds of ancillary projects in physics and radiobiology. In this review, we will discuss the evolution of carbon ion radiotherapy at the NIRS and some of the current and future projects in the field.
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Affiliation(s)
- Osama Mohamad
- Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
- Department of Radiation Oncology, University of Texas-Southwestern Medical Center, 2280 Inwood Rd., Dallas, TX 75390, USA.
| | - Hirokazu Makishima
- Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
| | - Tadashi Kamada
- Hospital of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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119
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Krieger M, Klimpki G, Fattori G, Hrbacek J, Oxley D, Safai S, Weber DC, Lomax AJ, Zhang Y. Experimental validation of a deforming grid 4D dose calculation for PBS proton therapy. ACTA ACUST UNITED AC 2018; 63:055005. [DOI: 10.1088/1361-6560/aaad1e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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120
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Internal Motion Estimation by Internal-external Motion Modeling for Lung Cancer Radiotherapy. Sci Rep 2018; 8:3677. [PMID: 29487330 PMCID: PMC5829085 DOI: 10.1038/s41598-018-22023-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 02/15/2018] [Indexed: 12/25/2022] Open
Abstract
The aim of this study is to develop an internal-external correlation model for internal motion estimation for lung cancer radiotherapy. Deformation vector fields that characterize the internal-external motion are obtained by respectively registering the internal organ meshes and external surface meshes from the 4DCT images via a recently developed local topology preserved non-rigid point matching algorithm. A composite matrix is constructed by combing the estimated internal phasic DVFs with external phasic and directional DVFs. Principle component analysis is then applied to the composite matrix to extract principal motion characteristics, and generate model parameters to correlate the internal-external motion. The proposed model is evaluated on a 4D NURBS-based cardiac-torso (NCAT) synthetic phantom and 4DCT images from five lung cancer patients. For tumor tracking, the center of mass errors of the tracked tumor are 0.8(±0.5)mm/0.8(±0.4)mm for synthetic data, and 1.3(±1.0)mm/1.2(±1.2)mm for patient data in the intra-fraction/inter-fraction tracking, respectively. For lung tracking, the percent errors of the tracked contours are 0.06(±0.02)/0.07(±0.03) for synthetic data, and 0.06(±0.02)/0.06(±0.02) for patient data in the intra-fraction/inter-fraction tracking, respectively. The extensive validations have demonstrated the effectiveness and reliability of the proposed model in motion tracking for both the tumor and the lung in lung cancer radiotherapy.
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121
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Anderle K, Stroom J, Vieira S, Pimentel N, Greco C, Durante M, Graeff C. Treatment planning with intensity modulated particle therapy for multiple targets in stage IV non-small cell lung cancer. Phys Med Biol 2018; 63:025034. [PMID: 29165322 DOI: 10.1088/1361-6560/aa9c62] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intensity modulated particle therapy (IMPT) can produce highly conformal plans, but is limited in advanced lung cancer patients with multiple lesions due to motion and planning complexity. A 4D IMPT optimization including all motion states was expanded to include multiple targets, where each target (isocenter) is designated to specific field(s). Furthermore, to achieve stereotactic treatment planning objectives, target and OAR weights plus objective doses were automatically iteratively adapted. Finally, 4D doses were calculated for different motion scenarios. The results from our algorithm were compared to clinical stereotactic body radiation treatment (SBRT) plans. The study included eight patients with 24 lesions in total. Intended dose regimen for SBRT was 24 Gy in one fraction, but lower fractionated doses had to be delivered in three cases due to OAR constraints or failed plan quality assurance. The resulting IMPT treatment plans had no significant difference in target coverage compared to SBRT treatment plans. Average maximum point dose and dose to specific volume in OARs were on average 65% and 22% smaller with IMPT. IMPT could also deliver 24 Gy in one fraction in a patient where SBRT was limited due to the OAR vicinity. The developed algorithm shows the potential of IMPT in treatment of multiple moving targets in a complex geometry.
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Affiliation(s)
- Kristjan Anderle
- GSI Helmholtz Centre for Heavy Ion Research, Planckstr. 1, 64291 Darmstadt, Germany
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Garibaldi C, Jereczek-Fossa BA, Marvaso G, Dicuonzo S, Rojas DP, Cattani F, Starzyńska A, Ciardo D, Surgo A, Leonardi MC, Ricotti R. Recent advances in radiation oncology. Ecancermedicalscience 2017; 11:785. [PMID: 29225692 PMCID: PMC5718253 DOI: 10.3332/ecancer.2017.785] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Indexed: 12/18/2022] Open
Abstract
Radiotherapy (RT) is very much a technology-driven treatment modality in the management of cancer. RT techniques have changed significantly over the past few decades, thanks to improvements in engineering and computing. We aim to highlight the recent developments in radiation oncology, focusing on the technological and biological advances. We will present state-of-the-art treatment techniques, employing photon beams, such as intensity-modulated RT, volumetric-modulated arc therapy, stereotactic body RT and adaptive RT, which make possible a highly tailored dose distribution with maximum normal tissue sparing. We will analyse all the steps involved in the treatment: imaging, delineation of the tumour and organs at risk, treatment planning and finally image-guidance for accurate tumour localisation before and during treatment delivery. Particular attention will be given to the crucial role that imaging plays throughout the entire process. In the case of adaptive RT, the precise identification of target volumes as well as the monitoring of tumour response/modification during the course of treatment is mainly based on multimodality imaging that integrates morphological, functional and metabolic information. Moreover, real-time imaging of the tumour is essential in breathing adaptive techniques to compensate for tumour motion due to respiration. Brief reference will be made to the recent spread of particle beam therapy, in particular to the use of protons, but also to the yet limited experience of using heavy particles such as carbon ions. Finally, we will analyse the latest biological advances in tumour targeting. Indeed, the effectiveness of RT has been improved not only by technological developments but also through the integration of radiobiological knowledge to produce more efficient and personalised treatment strategies.
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Affiliation(s)
- Cristina Garibaldi
- Unit of Medical Physics, European Institute of Oncology, 20141 Milan, Italy
| | - Barbara Alicja Jereczek-Fossa
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, 20122 Milan, Italy
| | - Giulia Marvaso
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
| | - Samantha Dicuonzo
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, 20122 Milan, Italy
| | - Damaris Patricia Rojas
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, 20122 Milan, Italy
| | - Federica Cattani
- Unit of Medical Physics, European Institute of Oncology, 20141 Milan, Italy
| | - Anna Starzyńska
- Department of Oral Surgery, Medical University of Gdańsk, 80–211 Gdańsk, Poland
| | - Delia Ciardo
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
| | - Alessia Surgo
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
| | | | - Rosalinda Ricotti
- Department of Radiation Oncology, European Institute of Oncology, 20141 Milan, Italy
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123
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Maspero M, van den Berg CAT, Landry G, Belka C, Parodi K, Seevinck PR, Raaymakers BW, Kurz C. Feasibility of MR-only proton dose calculations for prostate cancer radiotherapy using a commercial pseudo-CT generation method. Phys Med Biol 2017; 62:9159-9176. [PMID: 29076458 DOI: 10.1088/1361-6560/aa9677] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A magnetic resonance (MR)-only radiotherapy workflow can reduce cost, radiation exposure and uncertainties introduced by CT-MRI registration. A crucial prerequisite is generating the so called pseudo-CT (pCT) images for accurate dose calculation and planning. Many pCT generation methods have been proposed in the scope of photon radiotherapy. This work aims at verifying for the first time whether a commercially available photon-oriented pCT generation method can be employed for accurate intensity-modulated proton therapy (IMPT) dose calculation. A retrospective study was conducted on ten prostate cancer patients. For pCT generation from MR images, a commercial solution for creating bulk-assigned pCTs, called MR for Attenuation Correction (MRCAT), was employed. The assigned pseudo-Hounsfield Unit (HU) values were adapted to yield an increased agreement to the reference CT in terms of proton range. Internal air cavities were copied from the CT to minimise inter-scan differences. CT- and MRCAT-based dose calculations for opposing beam IMPT plans were compared by gamma analysis and evaluation of clinically relevant target and organ at risk dose volume histogram (DVH) parameters. The proton range in beam's eye view (BEV) was compared using single field uniform dose (SFUD) plans. On average, a [Formula: see text] mm) gamma pass rate of 98.4% was obtained using a [Formula: see text] dose threshold after adaptation of the pseudo-HU values. Mean differences between CT- and MRCAT-based dose in the DVH parameters were below 1 Gy ([Formula: see text]). The median proton range difference was [Formula: see text] mm, with on average 96% of all BEV dose profiles showing a range agreement better than 3 mm. Results suggest that accurate MR-based proton dose calculation using an automatic commercial bulk-assignment pCT generation method, originally designed for photon radiotherapy, is feasible following adaptation of the assigned pseudo-HU values.
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Affiliation(s)
- Matteo Maspero
- Center for Image Sciences, Universitair Medisch Centrum Utrecht, Utrecht, Netherlands
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124
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Bert C, Herfarth K. Management of organ motion in scanned ion beam therapy. Radiat Oncol 2017; 12:170. [PMID: 29110693 PMCID: PMC5674859 DOI: 10.1186/s13014-017-0911-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022] Open
Abstract
Scanned ion beam therapy has special demands for treatment of intra-fractionally moving tumors such as lesions in lung or liver. Interplay effects between beam and organ motion can in those settings lead to under-dosage of the target volume. Dedicated treatment techniques such as gating or abdominal compression are required. In addition 4D treatment planning should be used to determine strategies for patient specific treatment planning such as an increased beam focus or the use of internal target volumes incorporating range changes.Several work packages of the Clinical Research Units 214 and 214/2 funded by the German Research Council investigated the management of organ motion in scanned ion beam therapy. A focus was laid on 4D treatment planning using TRiP4D and the development of motion mitigation strategies including their quality assurance. This review focuses on the activity in the second funding period covering adaptive treatment planning strategies, 4D treatment plan optimization, and the application of motion management in pre-clinical research on radiation therapy of cardiac arrhythmias.
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Affiliation(s)
- Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany.
| | - Klaus Herfarth
- Heidelberg Ion-Beam Therapy Center (HIT) and Department of Radiation Oncology, University Clinic Heidelberg, Heidelberg, Germany
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125
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Ulrich S, Wieser HP, Cao W, Mohan R, Bangert M. Impact of respiratory motion on variable relative biological effectiveness in 4D-dose distributions of proton therapy. Acta Oncol 2017; 56:1420-1427. [PMID: 28828913 DOI: 10.1080/0284186x.2017.1354131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Organ motion during radiation therapy with scanned protons leads to deviations between the planned and the delivered physical dose. Using a constant relative biological effectiveness (RBE) of 1.1 linearly maps these deviations into RBE-weighted dose. However, a constant value cannot account for potential nonlinear variations in RBE suggested by variable RBE models. Here, we study the impact of motion on recalculations of RBE-weighted dose distributions using a phenomenological variable RBE model. MATERIAL AND METHODS 4D-dose calculation including variable RBE was implemented in the open source treatment planning toolkit matRad. Four scenarios were compared for one field and two field proton treatments for a liver cancer patient assuming (α∕β)x = 2 Gy and (α∕β)x = 10 Gy: (A) the optimized static dose distribution with constant RBE, (B) a static recalculation with variable RBE, (C) a 4D-dose recalculation with constant RBE and (D) a 4D-dose recalculation with variable RBE. For (B) and (D), the variable RBE was calculated by the model proposed by McNamara. For (C), the physical dose was accumulated with direct dose mapping; for (D), dose-weighted radio-sensitivity parameters of the linear quadratic model were accumulated to model synergistic irradiation effects on RBE. RESULTS Dose recalculation with variable RBE led to an elevated biological dose at the end of the proton field, while 4D-dose recalculation exhibited random deviations everywhere in the radiation field depending on the interplay of beam delivery and organ motion. For a single beam treatment assuming (α∕β)x = 2 Gy, D95% was 1.98 Gy (RBE) (A), 2.15 Gy (RBE) (B), 1.81 Gy (RBE) (C) and 1.98 Gy (RBE) (D). The homogeneity index was 1.04 (A), 1.08 (B), 1.23 (C) and 1.25 (D). CONCLUSION For the studied liver case, intrafractional motion did not reduce the modulation of the RBE-weighted dose postulated by variable RBE models for proton treatments.
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Affiliation(s)
- Silke Ulrich
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Hans-Peter Wieser
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Wenhua Cao
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, TX, USA
| | - Radhe Mohan
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, TX, USA
| | - Mark Bangert
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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Prall M, Eichhorn A, Richter D, Lehmann HI, Constantinescu A, Kaderka R, Lugenbiel P, Thomas D, Bert C, Packer DL, Durante M, Graeff C. Immobilization for carbon ion beam ablation of cardiac structures in a porcine model. Phys Med 2017; 43:134-139. [DOI: 10.1016/j.ejmp.2017.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/27/2017] [Accepted: 10/20/2017] [Indexed: 12/14/2022] Open
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Kostiukhina N, Georg D, Rollet S, Kuess P, Sipaj A, Andrzejewski P, Furtado H, Rausch I, Lechner W, Steiner E, Kertész H, Knäusl B. Advanced Radiation DOSimetry phantom (ARDOS): a versatile breathing phantom for 4D radiation therapy and medical imaging. Phys Med Biol 2017; 62:8136-8153. [PMID: 28817381 DOI: 10.1088/1361-6560/aa86ea] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A novel breathing phantom was designed for being used in conventional and ion-beam radiotherapy as well as for medical imaging. Accurate dose delivery and patient safety are aimed to be verified for four-dimensional (4D) treatment techniques compensating for breathing-induced tumor motion. The phantom includes anthropomorphic components representing an average human thorax. It consists of real tissue equivalent materials to fulfill the requirements for dosimetric experiments and imaging purposes. The different parts of the torso (lungs, chest wall, and ribs) and the tumor can move independently. Simple regular movements, as well as more advanced patient-specific breathing cycles are feasible while a reproducible setup can be guaranteed. The phantom provides the flexibility to use different types of dosimetric devices and was designed in a way that it is robust, transportable and easy to handle. Tolerance levels and the reliability of the phantom setup were determined in combination with tests on motion accuracy and reproducibility by using infrared optical tracking technology. Different imaging was performed including positron emission tomography imaging, 4D computed tomography as well as real-time in-room imaging. The initial dosimetric benchmarking studies were performed in a photon beam where dose parameters are predictable and the dosimetric procedures well established.
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Affiliation(s)
- Natalia Kostiukhina
- Division Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, Vienna, Austria. Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria. Health & Environment Department, Biomedical Systems, AIT Austrian Institute of Technology GmbH, Vienna, Austria
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Poulsen PR, Eley J, Langner U, Simone CB, Langen K. Efficient Interplay Effect Mitigation for Proton Pencil Beam Scanning by Spot-Adapted Layered Repainting Evenly Spread out Over the Full Breathing Cycle. Int J Radiat Oncol Biol Phys 2017; 100:226-234. [PMID: 29254775 DOI: 10.1016/j.ijrobp.2017.09.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 09/06/2017] [Accepted: 09/22/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To develop and implement a practical repainting method for efficient interplay effect mitigation in proton pencil beam scanning (PBS). METHODS AND MATERIALS A new flexible repainting scheme with spot-adapted numbers of repainting evenly spread out over the whole breathing cycle (assumed to be 4 seconds) was developed. Twelve fields from 5 thoracic and upper abdominal PBS plans were delivered 3 times using the new repainting scheme to an ion chamber array on a motion stage. One time was static and 2 used 4-second, 3-cm peak-to-peak sinusoidal motion with delivery started at maximum inhalation and maximum exhalation. For comparison, all dose measurements were repeated with no repainting and with 8 repaintings. For each motion experiment, the 3%/3-mm gamma pass rate was calculated using the motion-convolved static dose as the reference. Simulations were first validated with the experiments and then used to extend the study to 0- to 5-cm motion magnitude, 2- to 6-second motion periods, patient-measured liver tumor motion, and 1- to 6-fraction treatments. The effect of the proposed method was evaluated for the 5 clinical cases using 4-dimensional (4D) dose reconstruction in the planning 4D computed tomography scan. The target homogeneity index, HI = (D2 - D98)/Dmean, of a single-fraction delivery is reported, where D2 and D98 is the dose delivered to 2% and 98% of the target, respectively, and Dmean is the mean dose. RESULTS The gamma pass rates were 59.6% ± 9.7% with no repainting, 76.5% ± 10.8% with 8 repaintings, and 92.4% ± 3.8% with the new repainting scheme. Simulations reproduced the experimental gamma pass rates with a 1.3% root-mean-square error and demonstrated largely improved gamma pass rates with the new repainting scheme for all investigated motion scenarios. One- and two-fraction deliveries with the new repainting scheme had gamma pass rates similar to those of 3-4 and 6-fraction deliveries with 8 repaintings. The mean HI for the 5 clinical cases was 14.2% with no repainting, 13.7% with 8 repaintings, 12.0% with the new repainting scheme, and 11.6% for the 4D dose without interplay effects. CONCLUSIONS A novel repainting strategy for efficient interplay effect mitigation was proposed, implemented, and shown to outperform conventional repainting in experiments, simulations, and dose reconstructions. This strategy could allow for safe and more optimal clinical delivery of thoracic and abdominal proton PBS and better facilitate hypofractionated and stereotactic treatments.
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Affiliation(s)
| | - John Eley
- Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ulrich Langner
- Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Charles B Simone
- Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Katja Langen
- Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland
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129
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Mohan R, Das IJ, Ling CC. Empowering Intensity Modulated Proton Therapy Through Physics and Technology: An Overview. Int J Radiat Oncol Biol Phys 2017; 99:304-316. [PMID: 28871980 PMCID: PMC5651132 DOI: 10.1016/j.ijrobp.2017.05.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/11/2017] [Accepted: 05/02/2017] [Indexed: 01/15/2023]
Abstract
Considering the clinical potential of protons attributable to their physical characteristics, interest in proton therapy has increased greatly in this century, as has the number of proton therapy installations. Until recently, passively scattered proton therapy was used almost entirely. Notably, the overall clinical results to date have not shown a convincing benefit of protons over photons. A rapid transition is now occurring with the implementation of the most advanced form of proton therapy, intensity modulated proton therapy (IMPT). IMPT is superior to passively scattered proton therapy and intensity modulated radiation therapy (IMRT) dosimetrically. However, numerous limitations exist in the present IMPT methods. In particular, compared with IMRT, IMPT is highly vulnerable to various uncertainties. In this overview we identify three major areas of current limitations of IMPT: treatment planning, treatment delivery, and motion management, and discuss current and future efforts for improvement. For treatment planning, we need to reduce uncertainties in proton range and in computed dose distributions, improve robust planning and optimization, enhance adaptive treatment planning and delivery, and consider how to exploit the variability in the relative biological effectiveness of protons for clinical benefit. The quality of proton therapy also depends on the characteristics of the IMPT delivery systems and image guidance. Efforts are needed to optimize the beamlet spot size for both improved dose conformality and faster delivery. For the latter, faster energy switching time and increased dose rate are also needed. Real-time in-room volumetric imaging for guiding IMPT is in its early stages with cone beam computed tomography (CT) and CT-on-rails, and continued improvements are anticipated. In addition, imaging of the proton beams themselves, using, for instance, prompt γ emissions, is being developed to determine the proton range and to reduce range uncertainty. With the realization of the advances described above, we posit that IMPT, thus empowered, will lead to substantially improved clinical results.
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Affiliation(s)
- Radhe Mohan
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, Texas.
| | - Indra J Das
- Department of Radiation Oncology, New York University Langone Medical Center, New York, New York
| | - Clifton C Ling
- Varian Medical Systems and Department of Radiation Oncology, Stanford University, Stanford, California
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130
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Consensus Guidelines for Implementing Pencil-Beam Scanning Proton Therapy for Thoracic Malignancies on Behalf of the PTCOG Thoracic and Lymphoma Subcommittee. Int J Radiat Oncol Biol Phys 2017; 99:41-50. [DOI: 10.1016/j.ijrobp.2017.05.014] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/05/2017] [Accepted: 05/09/2017] [Indexed: 12/25/2022]
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131
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Chi A, Lin LC, Wen S, Yan H, Hsi WC. Comparison of photon volumetric modulated arc therapy, intensity-modulated proton therapy, and intensity-modulated carbon ion therapy for delivery of hypo-fractionated thoracic radiotherapy. Radiat Oncol 2017; 12:132. [PMID: 28810881 PMCID: PMC5558745 DOI: 10.1186/s13014-017-0866-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 08/09/2017] [Indexed: 02/08/2023] Open
Abstract
Purpose The aim of the present study was to compare the dose distribution generated from photon volumetric modulated arc therapy (VMAT), intensity modulated proton therapy (IMPT), and intensity modulated carbon ion therapy (IMCIT) in the delivery of hypo-fractionated thoracic radiotherapy. Methods and materials Ten selected patients who underwent thoracic particle therapy between 2015 and 2016 were re-planned to receive a relative biological effectiveness (RBE) weighted dose of 60 Gy (i.e., GyE) in 15 fractions delivered with VMAT, IMPT, or IMCIT with the same optimization criteria. Treatment plans were then compared. Results There were no significant differences in target volume dose coverage or dose conformity, except improved D95 was found with IMCIT compared with VMAT (p = 0.01), and IMCIT was significantly better than IMPT in all target volume dose parameters. Particle therapy led to more prominent lung sparing at low doses, and this result was most prominent with IMCIT (p < 0.05). Improved sparing of other thoracic organs at risk (OARs) was observed with particle therapy, and IMCIT further lowered the D1cc and D5cc for major blood vessels, as compared with IMPT (p = 0.01). Conclusion Although it was comparable to VMAT, IMCIT led to significantly better tumor target dose coverage and conformity than did IMPT. Particle therapy, compared with VMAT, improved thoracic OAR sparing. IMCIT, compared with IMPT, may further improve normal lung and major blood vessel sparing under limited respiratory motion. Electronic supplementary material The online version of this article (doi:10.1186/s13014-017-0866-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alexander Chi
- Shanghai Proton and Heavy Ion Center, Shanghai, China.
| | - Lien-Chun Lin
- Shanghai Proton and Heavy Ion Center, Shanghai, China
| | - Sijin Wen
- Department of Biostatistics, West Virginia University, Morgantown, WV, USA
| | - Haijuan Yan
- Department of Biostatistics, West Virginia University, Morgantown, WV, USA
| | - Wen-Chien Hsi
- Shanghai Proton and Heavy Ion Center, Shanghai, China.
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Bernatowicz K, Zhang Y, Perrin R, Weber DC, Lomax AJ. Advanced treatment planning using direct 4D optimisation for pencil-beam scanned particle therapy. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1361-6560/aa7ab8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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133
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Klimpki G, Psoroulas S, Bula C, Rechsteiner U, Eichin M, Weber DC, Lomax A, Meer D. A beam monitoring and validation system for continuous line scanning in proton therapy. ACTA ACUST UNITED AC 2017; 62:6126-6143. [DOI: 10.1088/1361-6560/aa772e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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134
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Batista V, Richter D, Combs SE, Jäkel O. Planning strategies for inter-fractional robustness in pancreatic patients treated with scanned carbon therapy. Radiat Oncol 2017; 12:94. [PMID: 28595643 PMCID: PMC5465513 DOI: 10.1186/s13014-017-0832-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 05/30/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Managing inter-fractional anatomy changes is a challenging task in radiotherapy of pancreatic tumors, especially in scanned carbon-ion delivery. This treatment planning study aims to focus on clinically feasible solutions, such as the beam angle selection and margin design to increase the robustness against inter-fractional uncertainties. METHODS This study included 10 patients with weekly 3D-CT imaging and physician-approved Clinical Target Volume (CTV). The study was directed to keep the CTV-coverage using six beam angle configurations in combination with different Internal Target Volume (ITV) concepts. These were: geometric-margin (symmetric 3 and 5 mm margin); range-equivalent margins with an isotropic HU replacement; and to evaluate the need of asymmetric margins the water-equivalent range path (WEPL) was determined per patient from the set of CTs. Plan optimization and forward dose calculation in each week-CT were performed with the research treatment planning system TRiP98 and the plan quality evaluated in terms of CTV coverage (V95CTV) and homogeneity dose (HCTV = D5-D95). RESULTS The beam geometry had a substantial impact on the target irradiation over the treatment course, with the single posterior or two beams showing the best average coverage of the CTV. The use of geometric margins for the more robust beam geometries showed acceptable results, with a V95CTV of (99.2 ± 1.2)% for the 5 mm-margin. For the non-robust configurations, due to substantial changes in the radiological depth, the use of this margin results in a V95CTV that might be below 80%, only showing improvement when the range changes are included. CONCLUSIONS Selection of adequate beam configurations and treatment margins in ion-beam therapy of pancreatic tumors is of great importance. For a single posterior beam or two beam configurations, application of geometrical margins compensate for dose degradation induced by inter-fractional anatomy changes for the majority of the analyzed treatment fractions.
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Affiliation(s)
- Vania Batista
- Hospital for Radiooncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg, Germany
| | - Daniel Richter
- University Clinic of Erlangen, Erlangen, Germany
- GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Stephanie E. Combs
- Hospital for Radiooncology and Radiation Therapy, Heidelberg University Hospital, Heidelberg, Germany
- Klinikum rechts der Isa, Technische Universität München, Muniche, Germany
| | - Oliver Jäkel
- Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany
- Division Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany
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Chi A, Chen H, Wen S, Yan H, Liao Z. Comparison of particle beam therapy and stereotactic body radiotherapy for early stage non-small cell lung cancer: A systematic review and hypothesis-generating meta-analysis. Radiother Oncol 2017; 123:346-354. [PMID: 28545956 DOI: 10.1016/j.radonc.2017.05.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 03/28/2017] [Accepted: 05/05/2017] [Indexed: 12/12/2022]
Abstract
PURPOSE To assess hypo-fractionated particle beam therapy (PBT)'s efficacy relative to that of photon stereotactic body radiotherapy (SBRT) for early stage (ES) non-small cell lung cancer (NSCLC). METHODS Eligible studies were identified through extensive searches of the PubMed, Medline, Google-scholar, and Cochrane library databases from 2000 to 2016. Original English publications of ES NSCLC were included. A meta-analysis was performed to compare the survival outcome, toxicity profile, and patterns of failure following each treatment. RESULTS 72 SBRT studies and 9 hypo-fractionated PBT studies (mostly single-arm) were included. PBT was associated with improved overall survival (OS; p=0.005) and progression-free survival (PFS; p=0.01) in the univariate meta-analysis. The OS benefit did not reach its statistical significance after inclusion of operability into the final multivariate meta-analysis (p=0.11); while the 3-year local control (LC) still favored PBT (p=0.03). CONCLUSION Although hypo-fractionated PBT may lead to additional clinical benefit when compared with photon SBRT, no statistically significant survival benefit from PBT over SBRT was observed in the treatment of ES NSCLC in this hypothesis-generating meta-analysis after adjusting for potential confounding variables.
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Affiliation(s)
- Alexander Chi
- Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, China.
| | - Haiquan Chen
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, China
| | - Sijin Wen
- Department of Biostatistics, School of Public Health, West Virginia University, Morgantown, USA.
| | - Haijuan Yan
- Department of Biostatistics, School of Public Health, West Virginia University, Morgantown, USA
| | - Zhongxing Liao
- Department of Radiation Oncology, MD Anderson Cancer Center, Houston, USA
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136
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Zhang Y, Huth I, Wegner M, Weber DC, Lomax AJ. Surface as a motion surrogate for gated re-scanned pencil beam proton therapy. Phys Med Biol 2017; 62:4046-4061. [DOI: 10.1088/1361-6560/aa66c5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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137
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Schwarz M, Cattaneo GM, Marrazzo L. Geometrical and dosimetrical uncertainties in hypofractionated radiotherapy of the lung: A review. Phys Med 2017; 36:126-139. [DOI: 10.1016/j.ejmp.2017.02.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/23/2016] [Accepted: 02/14/2017] [Indexed: 12/25/2022] Open
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138
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Fattori G, Safai S, Carmona PF, Peroni M, Perrin R, Weber DC, Lomax AJ. Monitoring of breathing motion in image-guided PBS proton therapy: comparative analysis of optical and electromagnetic technologies. Radiat Oncol 2017; 12:63. [PMID: 28359341 PMCID: PMC5374699 DOI: 10.1186/s13014-017-0797-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/08/2017] [Indexed: 02/07/2023] Open
Abstract
Background Motion monitoring is essential when treating non-static tumours with pencil beam scanned protons. 4D medical imaging typically relies on the detected body surface displacement, considered as a surrogate of the patient's anatomical changes, a concept similarly applied by most motion mitigation techniques. In this study, we investigate benefits and pitfalls of optical and electromagnetic tracking, key technologies for non-invasive surface motion monitoring, in the specific environment of image-guided, gantry-based proton therapy. Methods Polaris SPECTRA optical tracking system and the Aurora V3 electromagnetic tracking system from Northern Digital Inc. (NDI, Waterloo, CA) have been compared both technically, by measuring tracking errors and system latencies under laboratory conditions, and clinically, by assessing their practicalities and sensitivities when used with imaging devices and PBS treatment gantries. Additionally, we investigated the impact of using different surrogate signals, from different systems, on the reconstructed 4D CT images. Results Even though in controlled laboratory conditions both technologies allow for the localization of static fiducials with sub-millimetre jitter and low latency (31.6 ± 1 msec worst case), significant dynamic and environmental distortions limit the potential of the electromagnetic approach in a clinical setting. The measurement error in case of close proximity to a CT scanner is up to 10.5 mm and precludes its use for the monitoring of respiratory motion during 4DCT acquisitions. Similarly, the motion of the treatment gantry distorts up to 22 mm the tracking result. Conclusions Despite the line of sight requirement, the optical solution offers the best potential, being the most robust against environmental factors and providing the highest spatial accuracy. The significant difference in the temporal location of the reconstructed phase points is used to speculate on the need to apply the same monitoring system for imaging and treatment to ensure the consistency of detected phases.
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Affiliation(s)
- Giovanni Fattori
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | | | - Marta Peroni
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | - Rosalind Perrin
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland.,Radiation Oncology Department, Inselspital Universitätsspital Bern, 3010, Bern, Switzerland
| | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland. .,Department of Physics, ETH-Hönggerberg, 8093, Zurich, Switzerland.
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139
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Durante M, Orecchia R, Loeffler JS. Charged-particle therapy in cancer: clinical uses and future perspectives. Nat Rev Clin Oncol 2017; 14:483-495. [DOI: 10.1038/nrclinonc.2017.30] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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140
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Batista V, Chaudhri N, Richter D, Herfarth K, Jäkel O. Internal target volume margins for liver tumours treated with gated scanned carbon-ion radiotherapy. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa5988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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141
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Evaluation of residual abdominal tumour motion in carbon ion gated treatments through respiratory motion modelling. Phys Med 2017; 34:28-37. [DOI: 10.1016/j.ejmp.2017.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/22/2016] [Accepted: 01/11/2017] [Indexed: 11/21/2022] Open
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142
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Graeff C. Robustness of 4D-optimized scanned carbon ion beam therapy against interfractional changes in lung cancer. Radiother Oncol 2017; 122:387-392. [PMID: 28073579 DOI: 10.1016/j.radonc.2016.12.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/16/2016] [Accepted: 12/02/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Moving targets could be conformally treated with actively scanned carbon ion beams using 4D-optimization. As this heavily exploits 4D-CTs, an important question is whether the conformity also upholds in the context of interfractional changes, i.e. variable positioning, anatomy and breathing patterns. MATERIALS AND METHODS In 4 lung cancer patients, 6 weekly 4D-CTs were available. 4D-CTs and their phases were non-rigidly registered to propagate contours and 4D-doses. On the first 4D-CT, a 4D-optimized plan delivering a uniform dose to each motion phase (total dose 9.4Gy(RBE)) was simulated, as well as an ITV plan for comparison. On the five following 4D-CTs, 4D-dose was forward calculated and evaluated for target coverage and conformity. Variable uniform (3-7mm) and range margins (2mm/%) were investigated. RESULTS For all patients, target coverage (V95>95% accumulated over 5 fractions) could be achieved, but with variable margin size weakly depending on motion amplitude and range changes. The same margins were also necessary for ITV plans, which lead to lower conformity and higher integral doses. CONCLUSION 4D-optimization appears feasible also under interfractional changes and maintains a dosimetric advantage over less conformal ITV irradiations. Further studies are needed to identify patients benefiting most from the technically more complex 4D-optimization.
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Affiliation(s)
- Christian Graeff
- GSI Helmholzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
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143
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Feasibility Study on Cardiac Arrhythmia Ablation Using High-Energy Heavy Ion Beams. Sci Rep 2016; 6:38895. [PMID: 27996023 PMCID: PMC5171237 DOI: 10.1038/srep38895] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/09/2016] [Indexed: 01/19/2023] Open
Abstract
High-energy ion beams are successfully used in cancer therapy and precisely deliver high doses of ionizing radiation to small deep-seated target volumes. A similar noninvasive treatment modality for cardiac arrhythmias was tested here. This study used high-energy carbon ions for ablation of cardiac tissue in pigs. Doses of 25, 40, and 55 Gy were applied in forced-breath-hold to the atrioventricular junction, left atrial pulmonary vein junction, and freewall left ventricle of intact animals. Procedural success was tracked by (1.) in-beam positron-emission tomography (PET) imaging; (2.) intracardiac voltage mapping with visible lesion on ultrasound; (3.) lesion outcomes in pathohistolgy. High doses (40–55 Gy) caused slowing and interruption of cardiac impulse propagation. Target fibrosis was the main mediator of the ablation effect. In irradiated tissue, apoptosis was present after 3, but not 6 months. Our study shows feasibility to use high-energy ion beams for creation of cardiac lesions that chronically interrupt cardiac conduction.
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144
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Ciocca M, Mirandola A, Molinelli S, Russo S, Mastella E, Vai A, Mairani A, Magro G, Pella A, Donetti M, Valvo F, Fossati P, Baroni G. Commissioning of the 4-D treatment delivery system for organ motion management in synchrotron-based scanning ion beams. Phys Med 2016; 32:1667-1671. [DOI: 10.1016/j.ejmp.2016.11.107] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 12/26/2022] Open
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145
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Zhang Y, Huth I, Wegner M, Weber DC, Lomax AJ. An evaluation of rescanning technique for liver tumour treatments using a commercial PBS proton therapy system. Radiother Oncol 2016; 121:281-287. [DOI: 10.1016/j.radonc.2016.09.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 09/12/2016] [Accepted: 09/25/2016] [Indexed: 11/15/2022]
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146
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Kurz C, Bauer J, Unholtz D, Richter D, Herfarth K, Debus J, Parodi K. Initial clinical evaluation of PET-based ion beam therapy monitoring under consideration of organ motion. Med Phys 2016; 43:975-82. [PMID: 26843257 DOI: 10.1118/1.4940356] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
PURPOSE Intrafractional organ motion imposes considerable challenges to scanned ion beam therapy and demands for a thorough verification of the applied treatment. At the Heidelberg Ion-Beam Therapy Center (HIT), the scanned ion beam delivery is verified by means of postirradiation positron-emission-tomography (PET) imaging. This work presents a first clinical evaluation of PET-based treatment monitoring in ion beam therapy under consideration of target motion. METHODS Three patients with mobile liver lesions underwent scanned carbon ion irradiation at HIT and postirradiation PET/CT (x-ray-computed-tomography) imaging with a commercial scanner. Respiratory motion was recorded during irradiation and subsequent image acquisition. This enabled a time-resolved (4D) calculation of the expected irradiation-induced activity pattern and, for one patient where an additional 4D CT was acquired at the PET/CT scanner after treatment, a motion-compensated PET image reconstruction. For the other patients, PET data were reconstructed statically. To verify the treatment, calculated prediction and reconstructed measurement were compared with a focus on the ion beam range. RESULTS Results in the current three patients suggest that for motion amplitudes in the order of 2 mm there is no benefit from incorporating respiratory motion information into PET-based treatment monitoring. For a target motion in the order of 10 mm, motion-related effects become more severe and a time-resolved modeling of the expected activity distribution can lead to an improved data interpretation if a sufficient number of true coincidences is detected. Benefits from motion-compensated PET image reconstruction could not be shown conclusively at the current stage. CONCLUSIONS The feasibility of clinical PET-based treatment verification under consideration of organ motion has been shown for the first time. Improvements in noise-robust 4D PET image reconstruction are deemed necessary to enhance the clinical potential.
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Affiliation(s)
- Christopher Kurz
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Julia Bauer
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Daniel Unholtz
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Daniel Richter
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, GermanyStrahlenklinik, Universitätsklinikum Erlangen, Erlangen 91054, Germany
| | - Klaus Herfarth
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Jürgen Debus
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Katia Parodi
- Heidelberg Ion-Beam Therapy Center and Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg 69120, GermanyDepartment of Medical Physics, Ludwig-Maximilians-University, Munich 85748, Germany
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147
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Steitz J, Naumann P, Ulrich S, Haefner MF, Sterzing F, Oelfke U, Bangert M. Worst case optimization for interfractional motion mitigation in carbon ion therapy of pancreatic cancer. Radiat Oncol 2016; 11:134. [PMID: 27717378 PMCID: PMC5055683 DOI: 10.1186/s13014-016-0705-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 09/20/2016] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION The efficacy of radiation therapy treatments for pancreatic cancer is compromised by abdominal motion which limits the spatial accuracy for dose delivery - especially for particles. In this work we investigate the potential of worst case optimization for interfractional offline motion mitigation in carbon ion treatments of pancreatic cancer. METHODS We implement a worst case optimization algorithm that explicitly models the relative biological effectiveness of carbon ions during inverse planning. We perform a comparative treatment planning study for seven pancreatic cancer patients. Treatment plans that have been generated using worst case optimization are compared against (1) conventional intensity-modulated carbon ion therapy, (2) single field uniform dose carbon ion therapy, and (3) an ideal yet impractical scenario relying on daily re-planning. The dosimetric quality and robustness of the resulting treatment plans is evaluated using reconstructions of the daily delivered dose distributions on fractional control CTs. RESULTS Idealized daily re-planning consistently gives the best dosimetric results with regard to both target coverage and organ at risk sparing. The absolute reduction of D 95 within the gross tumor volume during fractional dose reconstruction is most pronounced for conventional intensity-modulated carbon ion therapy. Single field uniform dose optimization exhibits no substantial reduction for six of seven patients and values for D 95 for worst case optimization fall in between. The treated volume (D>95 % prescription dose) outside of the gross tumor volume is reduced by a factor of two by worst case optimization compared to conventional optimization and single field uniform dose optimization. Single field uniform dose optimization comes at an increased radiation exposure of normal tissues, e.g. ≈2 Gy (RBE) in the mean dose in the kidneys compared to conventional and worst case optimization and ≈4 Gy (RBE) in D 1 in the spinal cord compared to worst case optimization. CONCLUSION Interfractional motion substantially deteriorates dose distributions for carbon ion treatments of pancreatic cancer patients. Single field uniform dose optimization mitigates the negative influence of motion on target coverage at an increased radiation exposure of normal tissue. Worst case optimization enables an exploration of the trade-off between robust target coverage and organ at risk sparing during inverse treatment planning beyond margin concepts.
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Affiliation(s)
- Julian Steitz
- German Cancer Reserach Center - DKFZ, Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Patrick Naumann
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - Silke Ulrich
- German Cancer Reserach Center - DKFZ, Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Matthias F Haefner
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - Florian Sterzing
- German Cancer Reserach Center - DKFZ, Im Neuenheimer Feld 280, Heidelberg, Germany
- Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - Uwe Oelfke
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Mark Bangert
- German Cancer Reserach Center - DKFZ, Im Neuenheimer Feld 280, Heidelberg, Germany.
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148
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Kurz C, Kamp F, Park YK, Zöllner C, Rit S, Hansen D, Podesta M, Sharp GC, Li M, Reiner M, Hofmaier J, Neppl S, Thieke C, Nijhuis R, Ganswindt U, Belka C, Winey BA, Parodi K, Landry G. Investigating deformable image registration and scatter correction for CBCT-based dose calculation in adaptive IMPT. Med Phys 2016; 43:5635. [DOI: 10.1118/1.4962933] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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149
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Sterpin E, Barragan A, Souris K, Lee JA. [Robust treatment planning in proton therapy]. Cancer Radiother 2016; 20:523-9. [PMID: 27614528 DOI: 10.1016/j.canrad.2016.07.075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 07/19/2016] [Indexed: 11/28/2022]
Abstract
The concentration of the dose delivered by protons at the end of their path, the Bragg peak, has the potential to improve external radiotherapy treatments. Unfortunately, the main strength of the protons, their finite range, is also their greatest weakness. Any uncertainty on the range may lead to inadequate target coverage or excessive toxicity. The uncertainties have multiple origins and include, among others, ballistic errors, morphological modifications or inaccurate estimations of the physical quantities necessary to predict the proton range. Uncertainties have been part of daily practice in conventional radiotherapy with X-rays for a long time. However, dose distributions delivered with X-rays are much less sensitive to uncertainties than the ones delivered with protons. This relative insensitivity enabled the management of uncertainties through safety margins using a simple formalism. The conditions of validity of this formalism are much more restrictive for proton therapy, leading to the need of developing new tools and adapted strategies to manage accurately these uncertainties. The objective of this paper is to present a vision for the management of uncertainties in proton therapy in the continuity of formalisms established for X-rays. The latter are first summarized before discussing the necessary developments in order to consistently apply them to protons.
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Affiliation(s)
- E Sterpin
- Katholieke Universiteit Leuven, Department of Oncology, Laboratory of Experimental Radiotherapy, O&N I Herestraat 49, 3000 Leuven, Belgique; Université catholique de Louvain, Center of Molecular Imaging, Radiotherapy and Oncology, institut de recherche expérimentale et clinique, avenue Hippocrate 54, 1200 Brussels, Belgique.
| | - A Barragan
- Université catholique de Louvain, Center of Molecular Imaging, Radiotherapy and Oncology, institut de recherche expérimentale et clinique, avenue Hippocrate 54, 1200 Brussels, Belgique
| | - K Souris
- Université catholique de Louvain, Center of Molecular Imaging, Radiotherapy and Oncology, institut de recherche expérimentale et clinique, avenue Hippocrate 54, 1200 Brussels, Belgique
| | - J A Lee
- Université catholique de Louvain, Center of Molecular Imaging, Radiotherapy and Oncology, institut de recherche expérimentale et clinique, avenue Hippocrate 54, 1200 Brussels, Belgique
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150
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Fontana G, Riboldi M, Gianoli C, Chirvase CI, Villa G, Paganelli C, Summers PE, Tagaste B, Pella A, Fossati P, Ciocca M, Baroni G, Valvo F, Orecchia R. MRI quantification of pancreas motion as a function of patient setup for particle therapy -a preliminary study. J Appl Clin Med Phys 2016; 17:60-75. [PMID: 27685119 PMCID: PMC5874090 DOI: 10.1120/jacmp.v17i5.6236] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 03/31/2016] [Accepted: 03/23/2016] [Indexed: 01/01/2023] Open
Abstract
Particle therapy (PT) has shown positive therapeutic results in local control of locally advanced pancreatic lesions. PT effectiveness is highly influenced by target localization accuracy both in space, since the pancreas is located in proximity to radiosensitive vital organs, and in time as it is subject to substantial breathing-related motion. The purpose of this preliminary study was to quantify pancreas range of motion under typical PT treatment conditions. Three common immobilization devices (vacuum cushion, thermoplastic mask, and compressor belt) were evaluated on five male patients in prone and supine positions. Retrospective four-dimensional magnetic resonance imaging data were reconstructed for each condition and the pancreas was manually segmented on each of six breathing phases. A k-means algorithm was then applied on the manually segmented map in order to obtain clusters representative of the three pancreas segments: head, body, and tail. Centers of mass (COM) for the pancreas and its segments were computed, as well as their displacements with respect to a reference breathing phase (beginning exhalation). The median three-dimensional COM displacements were in the range of 3 mm. Latero-lateral and superior-inferior directions had a higher range of motion than the anterior-posterior direction. Motion analysis of the pancreas segments showed slightly lower COM displacements for the head cluster compared to the tail cluster, especially in prone position. Statistically significant differences were found within patients among the investigated setups. Hence a patient-specific approach, rather than a general strategy, is suggested to define the optimal treatment setup in the frame of a millimeter positioning accuracy.
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