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Lang Y, Jiang Z, Sun L, Xiang L, Ren L. Hybrid-supervised deep learning for domain transfer 3D protoacoustic image reconstruction. Phys Med Biol 2024; 69:10.1088/1361-6560/ad3327. [PMID: 38471184 PMCID: PMC11076107 DOI: 10.1088/1361-6560/ad3327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
Objective. Protoacoustic imaging showed great promise in providing real-time 3D dose verification of proton therapy. However, the limited acquisition angle in protoacoustic imaging induces severe artifacts, which impairs its accuracy for dose verification. In this study, we developed a hybrid-supervised deep learning method for protoacoustic imaging to address the limited view issue.Approach. We proposed a Recon-Enhance two-stage deep learning method. In the Recon-stage, a transformer-based network was developed to reconstruct initial pressure maps from raw acoustic signals. The network is trained in a hybrid-supervised approach, where it is first trained using supervision by the iteratively reconstructed pressure map and then fine-tuned using transfer learning and self-supervision based on the data fidelity constraint. In the enhance-stage, a 3D U-net is applied to further enhance the image quality with supervision from the ground truth pressure map. The final protoacoustic images are then converted to dose for proton verification.Main results. The results evaluated on a dataset of 126 prostate cancer patients achieved an average root mean squared errors (RMSE) of 0.0292, and an average structural similarity index measure (SSIM) of 0.9618, out-performing related start-of-the-art methods. Qualitative results also demonstrated that our approach addressed the limit-view issue with more details reconstructed. Dose verification achieved an average RMSE of 0.018, and an average SSIM of 0.9891. Gamma index evaluation demonstrated a high agreement (94.7% and 95.7% for 1%/3 mm and 1%/5 mm) between the predicted and the ground truth dose maps. Notably, the processing time was reduced to 6 s, demonstrating its feasibility for online 3D dose verification for prostate proton therapy.Significance. Our study achieved start-of-the-art performance in the challenging task of direct reconstruction from radiofrequency signals, demonstrating the great promise of PA imaging as a highly efficient and accurate tool forinvivo3D proton dose verification to minimize the range uncertainties of proton therapy to improve its precision and outcomes.
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Affiliation(s)
- Yankun Lang
- Department of Radiation Oncology Physics, University of Maryland, Baltimore, Baltimore, MD 21201, United States of America
| | - Zhuoran Jiang
- Department of Radiation Oncology, Duke University, Durham, NC 27710, United States of America
| | - Leshan Sun
- Department of Biomedical Engineering and Radiology, University of California, Irvine, Irnive, CA, 92617, United States of America
| | - Liangzhong Xiang
- Department of Biomedical Engineering and Radiology, University of California, Irvine, Irnive, CA, 92617, United States of America
| | - Lei Ren
- Department of Radiation Oncology Physics, University of Maryland, Baltimore, Baltimore, MD 21201, United States of America
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Schieferecke J, Gantz S, Hoffmann A, Pawelke J. Investigation of contrast mechanisms for MRI phase signal-based proton beam visualization in water phantoms. Magn Reson Med 2023; 90:1776-1788. [PMID: 37345700 DOI: 10.1002/mrm.29752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/23/2023]
Abstract
PURPOSE The low sensitivity and limitation to water phantoms of convection-dependent MRI magnitude signal-based proton beam visualization hinder its in vivo applicability in MR-integrated proton beam therapy. The purpose of the present study was, therefore, to assess possible contrast mechanisms for MRI phase signal-based proton beam visualization that can potentially be exploited to enhance the sensitivity of the method and extend its applicability to tissue materials. METHODS To assess whether proton beam-induced magnetic field perturbations, changes in material susceptibility or convection result in detectable changes in the MRI phase signal, water phantom characteristics, experiment timing, and imaging parameters were varied in combined irradiation and imaging experiments using a time-of-flight angiography pulse sequence on a prototype in-beam MRI scanner. Velocity encoding was used to further probe and quantify beam-induced convection. RESULTS MRI phase signal-based proton beam visualization proved feasible. The observed phase difference contrast was evoked by beam-induced buoyant convection with flow velocities in the mm/s range. Proton beam-induced magnetic field perturbations or changes in magnetic susceptibility did not influence the MRI phase signal. Velocity encoding was identified as a means to enhance the detection sensitivity. CONCLUSION Because the MRI phase difference contrast observed during proton beam irradiation of water phantoms is caused by beam-induced convection, this method will unlikely be transferable to tightly compartmentalized tissue wherein flow effects are restricted. However, strong velocity encoded pulse sequences were identified as promising candidates for the future development of MRI-based methods for water phantom-based geometric quality assurance in MR-integrated proton beam therapy.
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Affiliation(s)
- Juliane Schieferecke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Sebastian Gantz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Aswin Hoffmann
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
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Nenoff L, Sudhyadhom A, Lau J, Sharp GC, Paganetti H, Pursley J. Comparing Predicted Toxicities between Hypofractionated Proton and Photon Radiotherapy of Liver Cancer Patients with Different Adaptive Schemes. Cancers (Basel) 2023; 15:4592. [PMID: 37760560 PMCID: PMC10526201 DOI: 10.3390/cancers15184592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
With the availability of MRI linacs, online adaptive intensity modulated radiotherapy (IMRT) has become a treatment option for liver cancer patients, often combined with hypofractionation. Intensity modulated proton therapy (IMPT) has the potential to reduce the dose to healthy tissue, but it is particularly sensitive to changes in the beam path and might therefore benefit from online adaptation. This study compares the normal tissue complication probabilities (NTCPs) for liver and duodenal toxicity for adaptive and non-adaptive IMRT and IMPT treatments of liver cancer patients. Adaptive and non-adaptive IMRT and IMPT plans were optimized to 50 Gy (RBE = 1.1 for IMPT) in five fractions for 10 liver cancer patients, using the original MRI linac images and physician-drawn structures. Three liver NTCP models were used to predict radiation-induced liver disease, an increase in albumin-bilirubin level, and a Child-Pugh score increase of more than 2. Additionally, three duodenal NTCP models were used to predict gastric bleeding, gastrointestinal (GI) toxicity with grades >3, and duodenal toxicity grades 2-4. NTCPs were calculated for adaptive and non-adaptive IMRT and IMPT treatments. In general, IMRT showed higher NTCP values than IMPT and the differences were often significant. However, the differences between adaptive and non-adaptive treatment schemes were not significant, indicating that the NTCP benefit of adaptive treatment regimens is expected to be smaller than the expected difference between IMRT and IMPT.
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Affiliation(s)
- Lena Nenoff
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Atchar Sudhyadhom
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Radiation Oncology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Jackson Lau
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gregory C. Sharp
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Harald Paganetti
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jennifer Pursley
- Harvard Medical School, Boston, MA 02114, USA (J.P.)
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA
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Schieferecke J, Gantz S, Karsch L, Pawelke J, Hoffmann A. MRI magnitude signal-based proton beam visualisation in water phantoms reflects composite effects of beam-induced buoyant convection and radiation chemistry. Phys Med Biol 2023; 68:185002. [PMID: 37607554 DOI: 10.1088/1361-6560/acf2e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
Objective. Local magnetic resonance (MR) signal loss was previously observed during proton beam irradiation of free-floating water phantoms at ambient temperature using a research prototype in-beam magnetic resonance imaging (MRI) scanner. The emergence of this MR signal loss was hypothesised to be dependent on beam-induced convection. The aim of this study was therefore to unravel whether physical conditions allowing the development of convection must prevail for the beam-induced MRI signatures to emerge.Approach. The convection dependence of MRI magnitude signal-based proton beam visualisation was investigated in combined irradiation and imaging experiments using a gradient echo (GE)-based time-of-flight (ToF) angiography pulse sequence, which was first tested for its suitability for proton beam visualisation in free-floating water phantoms at ambient temperature. Subsequently, buoyant convection was selectively suppressed in water phantoms using either mechanical barriers or temperature control of water expansivity. The underlying contrast mechanism was further assessed using sagittal imaging and variation of T1 relaxation time-weighting.Main results. In the absence of convection-driven water flow, weak beam-induced MR signal changes occurred, whereas strong changes did occur when convection was not mechanically or thermally inhibited. Moreover, the degree of signal loss was found to change with the variation of T1-weighting. Consequently, beam-induced MR signal loss in free-floating water phantoms at ambient temperature does not exclusively originate from buoyant convection, but is caused by local composite effects of beam-induced motion and radiation chemistry resulting in a local change in the water T1 relaxation time.Significance. The identification of ToF angiography sequence-based proton beam visualisation in water phantoms to result from composite effects of beam-induced motion and radiation chemistry represents the starting point for the future elucidation of the currently unexplained motion-based MRI contrast mechanism and the identification of the proton beam-induced material change causing T1 relaxation time lengthening.
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Affiliation(s)
- Juliane Schieferecke
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Sebastian Gantz
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Leonhard Karsch
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Jörg Pawelke
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Aswin Hoffmann
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Gantz S, Karsch L, Pawelke J, Peter J, Schellhammer S, Smeets J, van der Kraaij E, Hoffmann A. Direct visualization of proton beam irradiation effects in liquids by MRI. Proc Natl Acad Sci U S A 2023; 120:e2301160120. [PMID: 37252953 PMCID: PMC10265969 DOI: 10.1073/pnas.2301160120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/06/2023] [Indexed: 06/01/2023] Open
Abstract
The main advantage proton beams offer over photon beams in radiation therapy of cancer patients is the dose maximum at their finite range, yielding a reduction in the dose deposited in healthy tissues surrounding the tumor. Since no direct method exists to measure the beam's range during dose delivery, safety margins around the tumor are applied, compromising the dose conformality and reducing the targeting accuracy. Here, we demonstrate that online MRI can visualize the proton beam and reveal its range during irradiation of liquid-filled phantoms. A clear dependence on beam energy and current was found. These results stimulate research into novel MRI-detectable beam signatures and already find application in the geometric quality assurance for magnetic resonance-integrated proton therapy systems currently under development.
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Affiliation(s)
- Sebastian Gantz
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Leonhard Karsch
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Jörg Pawelke
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Juliane Peter
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Sonja Schellhammer
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
| | - Julien Smeets
- Ion Beam Applications SA, 1348Louvain-la-Neuve, Belgium
| | | | - Aswin Hoffmann
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden–Rossendorf, 01309Dresden, Germany
- Division of Medical Radiation Physics, Institute of Radiooncology–OncoRay, Helmholtz-Zentrum Dresden–Rossendorf, 01328Dresden, Germany
- Division of Medical Radiation Physics, Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307Dresden, Germany
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Jiang Z, Sun L, Yao W, Wu QJ, Xiang L, Ren L. 3D in vivodose verification in prostate proton therapy with deep learning-based proton-acoustic imaging. Phys Med Biol 2022; 67:10.1088/1361-6560/ac9881. [PMID: 36206745 PMCID: PMC9647484 DOI: 10.1088/1361-6560/ac9881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/07/2022] [Indexed: 02/10/2023]
Abstract
Dose delivery uncertainty is a major concern in proton therapy, adversely affecting the treatment precision and outcome. Recently, a promising technique, proton-acoustic (PA) imaging, has been developed to provide real-timein vivo3D dose verification. However, its dosimetry accuracy is limited due to the limited-angle view of the ultrasound transducer. In this study, we developed a deep learning-based method to address the limited-view issue in the PA reconstruction. A deep cascaded convolutional neural network (DC-CNN) was proposed to reconstruct 3D high-quality radiation-induced pressures using PA signals detected by a matrix array, and then derive precise 3D dosimetry from pressures for dose verification in proton therapy. To validate its performance, we collected 81 prostate cancer patients' proton therapy treatment plans. Dose was calculated using the commercial software RayStation and was normalized to the maximum dose. The PA simulation was performed using the open-source k-wave package. A matrix ultrasound array with 64 × 64 sensors and 500 kHz central frequency was simulated near the perineum to acquire radiofrequency (RF) signals during dose delivery. For realistic acoustic simulations, tissue heterogeneity and attenuation were considered, and Gaussian white noise was added to the acquired RF signals. The proposed DC-CNN was trained on 204 samples from 69 patients and tested on 26 samples from 12 other patients. Predicted 3D pressures and dose maps were compared against the ground truth qualitatively and quantitatively using root-mean-squared-error (RMSE), gamma-index (GI), and dice coefficient of isodose lines. Results demonstrated that the proposed method considerably improved the limited-view PA image quality, reconstructing pressures with clear and accurate structures and deriving doses with a high agreement with the ground truth. Quantitatively, the pressure accuracy achieved an RMSE of 0.061, and the dose accuracy achieved an RMSE of 0.044, GI (3%/3 mm) of 93.71%, and 90%-isodose line dice of 0.922. The proposed method demonstrates the feasibility of achieving high-quality quantitative 3D dosimetry in PA imaging using a matrix array, which potentially enables the online 3D dose verification for prostate proton therapy.
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Affiliation(s)
- Zhuoran Jiang
- Medical Physics Graduate Program, Duke University, Durham, NC, 27705, USA
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Leshan Sun
- Department of Biomedical Engineering, University of California, Irvine, California 92617, USA
| | - Weiguang Yao
- Department of Radiation Oncology, University of Maryland, Baltimore, MD, 21201, USA
| | - Q. Jackie Wu
- Medical Physics Graduate Program, Duke University, Durham, NC, 27705, USA
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Liangzhong Xiang
- Department of Biomedical Engineering, University of California, Irvine, California 92617, USA
- Department of Radiological Sciences, University of California, Irvine, CA 92697, USA
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, Irvine, CA 92612, USA
| | - Lei Ren
- Department of Radiation Oncology, University of Maryland, Baltimore, MD, 21201, USA
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Polf JC, Barajas CA, Peterson SW, Mackin DS, Beddar S, Ren L, Gobbert MK. Applications of Machine Learning to Improve the Clinical Viability of Compton Camera Based in vivo Range Verification in Proton Radiotherapy. FRONTIERS IN PHYSICS 2022; 10:838273. [PMID: 36119562 PMCID: PMC9481064 DOI: 10.3389/fphy.2022.838273] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We studied the application of a deep, fully connected Neural Network (NN) to process prompt gamma (PG) data measured by a Compton camera (CC) during the delivery of clinical proton radiotherapy beams. The network identifies 1) recorded "bad" PG events arising from background noise during the measurement, and 2) the correct ordering of PG interactions in the CC to help improve the fidelity of "good" data used for image reconstruction. PG emission from a tissue-equivalent target during irradiation with a 150 MeV proton beam delivered at clinical dose rates was measured with a prototype CC. Images were reconstructed from both the raw measured data and the measured data that was further processed with a neural network (NN) trained to identify "good" and "bad" PG events and predict the ordering of individual interactions within the good PG events. We determine if NN processing of the CC data could improve the reconstructed PG images to a level in which they could provide clinically useful information about the in vivo range and range shifts of the proton beams delivered at full clinical dose rates. Results showed that a deep, fully connected NN improved the achievable contrast to noise ratio (CNR) in our images by more than a factor of 8x. This allowed the path, range, and lateral width of the clinical proton beam within a tissue equivalent target to easily be identified from the PG images, even at the highest dose rates of a 150 MeV proton beam used for clinical treatments. On average, shifts in the beam range as small as 3 mm could be identified. However, when limited by the amount of PG data measured with our prototype CC during the delivery of a single proton pencil beam (~1 × 109 protons), the uncertainty in the reconstructed PG images limited the identification of range shift to ~5 mm. Substantial improvements in CC images were obtained during clinical beam delivery through NN pre-processing of the measured PG data. We believe this shows the potential of NNs to help improve and push CC-based PG imaging toward eventual clinical application for proton RT treatment delivery verification.
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Affiliation(s)
- Jerimy C. Polf
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Carlos A. Barajas
- Department of Mathematics and Statistics, University of Maryland Baltimore County, Baltimore, MD, United States
| | | | - Dennis S. Mackin
- Department of Medical Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States
| | - Sam Beddar
- Department of Medical Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States
| | - Lei Ren
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Matthias K. Gobbert
- Department of Mathematics and Statistics, University of Maryland Baltimore County, Baltimore, MD, United States
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Heymans SV, Carlier B, Toumia Y, Nooijens S, Ingram M, Giammanco A, d'Agostino E, Crijns W, Bertrand A, Paradossi G, Himmelreich U, D'hooge J, Sterpin E, Van Den Abeele K. Modulating ultrasound contrast generation from injectable nanodroplets for proton range verification by varying the degree of superheat. Med Phys 2021; 48:1983-1995. [PMID: 33587754 DOI: 10.1002/mp.14778] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 01/21/2021] [Accepted: 02/08/2021] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Despite the physical benefits of protons over conventional photon radiation in cancer treatment, range uncertainties impede the ability to harness the full potential of proton therapy. While monitoring the proton range in vivo could reduce the currently adopted safety margins, a routinely applicable range verification technique is still lacking. Recently, phase-change nanodroplets were proposed for proton range verification, demonstrating a reproducible relationship between the proton range and generated ultrasound contrast after radiation-induced vaporization at 25°C. In this study, previous findings are extended with proton irradiations at different temperatures, including the physiological temperature of 37°C, for a novel nanodroplet formulation. Moreover, the potential to modulate the linear energy transfer (LET) threshold for vaporization by varying the degree of superheat is investigated, where the aim is to demonstrate vaporization of nanodroplets directly by primary protons. METHODS Perfluorobutane nanodroplets with a shell made of polyvinyl alcohol (PVA-PFB) or 10,12-pentacosadyinoic acid (PCDA-PFB) were dispersed in polyacrylamide hydrogels and irradiated with 62 MeV passively scattered protons at temperatures of 37°C and 50°C. Nanodroplet transition into echogenic microbubbles was assessed using ultrasound imaging (gray value and attenuation analysis) and optical images. The proton range was measured independently and compared to the generated contrast. RESULTS Nanodroplet design proved crucial to ensure thermal stability, as PVA-shelled nanodroplets dramatically outperformed their PCDA-shelled counterpart. At body temperature, a uniform radiation response proximal to the Bragg peak is attributed to nuclear reaction products interacting with PVA-PFB nanodroplets, with the 50% drop in ultrasound contrast being 0.17 mm ± 0.20 mm (mean ± standard deviation) in front of the proton range. Also at 50°C, highly reproducible ultrasound contrast profiles were obtained with shifts of -0.74 mm ± 0.09 mm (gray value analysis), -0.86 mm ± 0.04 mm (attenuation analysis) and -0.64 mm ± 0.29 mm (optical analysis). Moreover, a strong contrast enhancement was observed near the Bragg peak, suggesting that nanodroplets were sensitive to primary protons. CONCLUSIONS By varying the degree of superheat of the nanodroplets' core, one can modulate the intensity of the generated ultrasound contrast. Moreover, a submillimeter reproducible relationship between the ultrasound contrast and the proton range was obtained, either indirectly via the visualization of secondary reaction products or directly through the detection of primary protons, depending on the degree of superheat. The potential of PVA-PFB nanodroplets for in vivo proton range verification was confirmed by observing a reproducible radiation response at physiological temperature, and further studies aim to assess the nanodroplets' performance in a physiological environment. Ultimately, cost-effective online or offline ultrasound imaging of radiation-induced nanodroplet vaporization could facilitate the reduction of safety margins in treatment planning and enable adaptive proton therapy.
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Affiliation(s)
- Sophie V Heymans
- Department of Physics, KU Leuven Campus Kulak, Kortrijk, Belgium
| | - Bram Carlier
- Department of Oncology, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center, KU Leuven, Leuven, Belgium
| | - Yosra Toumia
- Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Sjoerd Nooijens
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Marcus Ingram
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | | | | | | | | | - Gaio Paradossi
- Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Uwe Himmelreich
- Molecular Small Animal Imaging Center, KU Leuven, Leuven, Belgium.,Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Jan D'hooge
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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Yao S, Hu Z, Zhang X, Lou E, Liang Z, Wang Y, Peng H. Feasibility study of range verification based on proton-induced acoustic signals and recurrent neural network. ACTA ACUST UNITED AC 2020; 65:215017. [DOI: 10.1088/1361-6560/abaa5e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Vogel J, Carmona R, Ainsley CG, Lustig RA. The Promise of Proton Therapy for Central Nervous System Malignancies. Neurosurgery 2020; 84:1000-1010. [PMID: 30476191 DOI: 10.1093/neuros/nyy454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 08/28/2018] [Indexed: 11/15/2022] Open
Abstract
Radiation therapy plays a significant role in management of benign and malignant diseases of the central nervous system. Patients may be at risk of acute and late toxicity from radiation therapy due to dose deposition in critical normal structures. In contrast to conventional photon delivery techniques, proton therapy is characterized by Bragg peak dose deposition which results in decreased exit dose beyond the target and greater sparing of normal structure which may reduce the rate of late toxicities from treatment. Dosimetric studies have demonstrated reduced dose to normal structures using proton therapy as compared to photon therapy. In addition, clinical studies are being reported demonstrating safety, feasibility, and low rates of acute toxicity. Technical challenges in proton therapy remain, including full understanding of depth of proton penetration and the biological activity in the distal Bragg peak. In addition, longer clinical follow-up is required to demonstrate reduction in late toxicities as compared to conventional photon-based radiation techniques. In this review, we summarize the current clinical literature and areas of active investigation in proton therapy for adult central nervous system malignancies.
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Affiliation(s)
- Jennifer Vogel
- Department of Rad-iation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ruben Carmona
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania
| | - Christopher G Ainsley
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania
| | - Robert A Lustig
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania
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Hsieh CE, Venkatesulu BP, Lee CH, Hung SP, Wong PF, Aithala SP, Kim BK, Rao A, Tung-Chieh Chang J, Tsang NM, Wang CC, Lee CC, Lin CC, Tseng JH, Chou WC, Wang YC, Krishnan S, Hong JH. Predictors of Radiation-Induced Liver Disease in Eastern and Western Patients With Hepatocellular Carcinoma Undergoing Proton Beam Therapy. Int J Radiat Oncol Biol Phys 2019; 105:73-86. [PMID: 30797890 DOI: 10.1016/j.ijrobp.2019.02.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 02/03/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE To identify predictors of radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) treated with proton beam therapy (PBT). METHODS This multicenter study included 136 patients with HCC (eastern, n = 102; western, n = 34) without evidence of intrahepatic tumor progression after PBT. The RILD was defined as ascites with alkaline-phosphatase abnormality, grade ≥3 hepatic toxicity, or Child-Pugh score worsening by ≥2 within 4 months after PBT completion. The proton doses were converted to equivalent doses in 2-GyE fractions. The unirradiated liver volume (ULV) was defined as the absolute liver volume (LV) receiving <1 GyE; the standard liver volume (SLV) was calculated using body surface area. Possible correlations of clinicodosimetric parameters with RILD were examined. RESULTS The mean pretreatment LV was 85% of SLV, and patients with a history of hepatectomy (P < .001) or hepatitis B virus infection (P = .035) had significantly smaller LV/SLV. Nineteen (14%) patients developed RILD. Multivariate logistic regression analysis identified ULV/SLV (P = .001), gross tumor volume (P = .001), and Child-Pugh classification (P = .002) as independent RILD predictors, and mean liver dose and target-delivered dose were not associated with RILD occurrence. A "volume-response" relationship between ULV/SLV and RILD was consistently observed in both eastern and western cohorts. In Child-Pugh class-A patients whose ULV/SLV were ≥50%, 49.9%-40%, 39.9%-30% and <30%, the RILD incidences were 0%, 6%, 16%, and 39% (P < .001), respectively. For the Child-Pugh class-B group, the RILD incidences in patients with ≥60%, 59.9%-40%, and <40% of ULV/SLV were 0%, 14%, and 83% (P = .006), respectively. CONCLUSIONS The ULV/SLV, not mean liver dose, independently predicts RILD in patients with HCC undergoing PBT. The relative and absolute contraindications for Child-Pugh class-A patient's ULV/SLV are <50% and <30%, and <60% and <40% for Child-Pugh class-B patients, respectively. Our results indicate that the likelihood of hepatic complications for PBT is dictated by similar metrics as that for surgery.
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Affiliation(s)
- Cheng-En Hsieh
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China; Department of Experimental Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas MD Anderson Cancer Center-UT Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Bhanu Prasad Venkatesulu
- Department of Experimental Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ching-Hsin Lee
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Sheng-Ping Hung
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Pei-Fong Wong
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Sathvik Panambur Aithala
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Byung Kyu Kim
- Department of Experimental Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas MD Anderson Cancer Center-UT Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Arvind Rao
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan
| | - Joseph Tung-Chieh Chang
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Ngan-Ming Tsang
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China; School of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Chun-Chieh Wang
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China; Department of Medical Imaging and Radiological Science, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Chung-Chi Lee
- Department of Medical Imaging and Radiological Science, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Chen-Chun Lin
- Department of Gastroenterology and Hepatology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Jeng-Hwei Tseng
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Wen-Chi Chou
- Department of Medical Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Yu-Chao Wang
- Department of Surgery, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China
| | - Sunil Krishnan
- Department of Experimental Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; The University of Texas MD Anderson Cancer Center-UT Health Graduate School of Biomedical Sciences, Houston, Texas; Department of Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ji-Hong Hong
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China; Department of Institute for Radiological Research, Chang Gung Memorial Hospital, Linkou and College of Medicine, Chang Gung University, Taoyuan City, Taiwan, China.
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12
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Parodi K, Polf JC. In vivo range verification in particle therapy. Med Phys 2018; 45:e1036-e1050. [PMID: 30421803 DOI: 10.1002/mp.12960] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/11/2018] [Accepted: 05/01/2018] [Indexed: 12/19/2022] Open
Abstract
Exploitation of the full potential offered by ion beams in clinical practice is still hampered by several sources of treatment uncertainties, particularly related to the limitations of our ability to locate the position of the Bragg peak in the tumor. To this end, several efforts are ongoing to improve the characterization of patient position, anatomy, and tissue stopping power properties prior to treatment as well as to enable in vivo verification of the actual dose delivery, or at least beam range, during or shortly after treatment. This contribution critically reviews methods under development or clinical testing for verification of ion therapy, based on pretreatment range and tissue probing as well as the detection of secondary emissions or physiological changes during and after treatment, trying to disentangle approaches of general applicability from those more specific to certain anatomical locations. Moreover, it discusses future directions, which could benefit from an integration of multiple modalities or address novel exploitation of the measurable signals for biologically adapted therapy.
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Affiliation(s)
- Katia Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. Munich, 85748, Germany
| | - Jerimy C Polf
- Deparment of Radiation Oncology, Maryland Proton Treatment Center, University of Maryland School of Medicine, 22 South Greene St., Baltimore, MD, 21201, USA
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The technological basis for adaptive ion beam therapy at MedAustron: Status and outlook. Z Med Phys 2018; 28:196-210. [DOI: 10.1016/j.zemedi.2017.09.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/02/2017] [Accepted: 09/18/2017] [Indexed: 11/22/2022]
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Uh J, Krasin MJ, Hua CH. Technical Note: Feasibility of MRI-based estimation of water-equivalent path length to detect changes in proton range during treatment courses. Med Phys 2018; 45:1677-1683. [DOI: 10.1002/mp.12822] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/25/2018] [Accepted: 02/08/2018] [Indexed: 12/24/2022] Open
Affiliation(s)
- Jinsoo Uh
- Department of Radiation Oncology; St. Jude Children's Research Hospital; Memphis TN 38105-3678 USA
| | - Matthew J. Krasin
- Department of Radiation Oncology; St. Jude Children's Research Hospital; Memphis TN 38105-3678 USA
| | - Chia-ho Hua
- Department of Radiation Oncology; St. Jude Children's Research Hospital; Memphis TN 38105-3678 USA
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Direct dose correlation of MRI morphologic alterations of healthy liver tissue after robotic liver SBRT. Strahlenther Onkol 2018; 194:414-424. [PMID: 29404626 DOI: 10.1007/s00066-018-1271-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/16/2018] [Indexed: 12/23/2022]
Abstract
PURPOSE For assessing healthy liver reactions after robotic SBRT (stereotactic body radiotherapy), we investigated early morphologic alterations on MRI (magnetic resonance imaging) with respect to patient and treatment plan parameters. PATIENTS AND METHODS MRI data at 6-17 weeks post-treatment from 22 patients with 42 liver metastases were analyzed retrospectively. Median prescription dose was 40 Gy delivered in 3-5 fractions. T2- and T1-weighted MRI were registered to the treatment plan. Absolute doses were converted to EQD2 (Equivalent dose in 2Gy fractions) with α/β-ratios of 2 and 3 Gy for healthy, and 8 Gy for modelling pre-damaged liver tissue. RESULTS Sharply defined, centroid-shaped morphologic alterations were observed outside the high-dose volume surrounding the GTV. On T2-w MRI, hyperintensity at EQD2 isodoses of 113.3 ± 66.1 Gy2, 97.5 ± 54.7 Gy3, and 66.5 ± 32.0 Gy8 significantly depended on PTV dimension (p = 0.02) and healthy liver EQD2 (p = 0.05). On T1-w non-contrast MRI, hypointensity at EQD2 isodoses of 113.3 ± 49.3 Gy2, 97.4 ± 41.0 Gy3, and 65.7 ± 24.2 Gy8 significantly depended on prior chemotherapy (p = 0.01) and total liver volume (p = 0.05). On T1-w gadolinium-contrast delayed MRI, hypointensity at EQD2 isodoses of 90.6 ± 42.5 Gy2, 79.3 ± 35.3 Gy3, and 56.6 ± 20.9 Gy8 significantly depended on total (p = 0.04) and healthy (p = 0.01) liver EQD2. CONCLUSIONS Early post-treatment changes in healthy liver tissue after robotic SBRT could spatially be correlated to respective isodoses. Median nominal doses of 10.1-11.3 Gy per fraction (EQD2 79-97 Gy3) induce characteristic morphologic alterations surrounding the lesions, potentially allowing for dosimetric in-vivo accuracy assessments. Comparison to other techniques and investigations of the short- and long-term clinical impact require further research.
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Jones KC, Nie W, Chu JCH, Turian JV, Kassaee A, Sehgal CM, Avery S. Acoustic-based proton range verification in heterogeneous tissue: simulation studies. Phys Med Biol 2018; 63:025018. [PMID: 29176057 DOI: 10.1088/1361-6560/aa9d16] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acoustic-based proton range verification (protoacoustics) is a potential in vivo technique for determining the Bragg peak position. Previous measurements and simulations have been restricted to homogeneous water tanks. Here, a CT-based simulation method is proposed and applied to a liver and prostate case to model the effects of tissue heterogeneity on the protoacoustic amplitude and time-of-flight range verification accuracy. For the liver case, posterior irradiation with a single proton pencil beam was simulated for detectors placed on the skin. In the prostate case, a transrectal probe measured the protoacoustic pressure generated by irradiation with five separate anterior proton beams. After calculating the proton beam dose deposition, each CT voxel's material properties were mapped based on Hounsfield Unit values, and thermoacoustically-generated acoustic wave propagation was simulated with the k-Wave MATLAB toolbox. By comparing the simulation results for the original liver CT to homogenized variants, the effects of heterogeneity were assessed. For the liver case, 1.4 cGy of dose at the Bragg peak generated 50 mPa of pressure (13 cm distal), a 2× lower amplitude than simulated in a homogeneous water tank. Protoacoustic triangulation of the Bragg peak based on multiple detector measurements resulted in 0.4 mm accuracy for a δ-function proton pulse irradiation of the liver. For the prostate case, higher amplitudes are simulated (92-1004 mPa) for closer detectors (<8 cm). For four of the prostate beams, the protoacoustic range triangulation was accurate to ⩽1.6 mm (δ-function proton pulse). Based on the results, application of protoacoustic range verification to heterogeneous tissue will result in decreased signal amplitudes relative to homogeneous water tank measurements, but accurate range verification is still expected to be possible.
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Affiliation(s)
- Kevin C Jones
- Department of Radiation Oncology, Rush University Medical Center, Chicago, IL, United States of America. Author to whom correspondence should be addressed
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Giordanengo S, Manganaro L, Vignati A. Review of technologies and procedures of clinical dosimetry for scanned ion beam radiotherapy. Phys Med 2017; 43:79-99. [DOI: 10.1016/j.ejmp.2017.10.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 09/23/2017] [Accepted: 10/18/2017] [Indexed: 12/17/2022] Open
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Kipergil EA, Erkol H, Kaya S, Gulsen G, Unlu MB. An analysis of beam parameters on proton-acoustic waves through an analytic approach. Phys Med Biol 2017; 62:4694-4710. [PMID: 28252450 DOI: 10.1088/1361-6560/aa642c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
It has been reported that acoustic waves are generated when a high-energy pulsed proton beam is deposited in a small volume within tissue. One possible application of proton-induced acoustics is to get real-time feedback for intra-treatment adjustments by monitoring such acoustic waves. A high spatial resolution in ultrasound imaging may reduce proton range uncertainty. Thus, it is crucial to understand the dependence of the acoustic waves on the proton beam characteristics. In this manuscript, firstly, an analytic solution for the proton-induced acoustic wave is presented to reveal the dependence of the signal on the beam parameters; then it is combined with an analytic approximation of the Bragg curve. The influence of the beam energy, pulse duration and beam diameter variation on the acoustic waveform are investigated. Further analysis is performed regarding the Fourier decomposition of the proton-acoustic signals. Our results show that the smaller spill time of the proton beam upsurges the amplitude of the acoustic wave for a constant number of protons, which is hence beneficial for dose monitoring. The increase in the energy of each individual proton in the beam leads to the spatial broadening of the Bragg curve, which also yields acoustic waves of greater amplitude. The pulse duration and the beam width of the proton beam do not affect the central frequency of the acoustic wave, but they change the amplitude of the spectral components.
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Evaluation of Focal Liver Reaction after Proton Beam Therapy for Hepatocellular Carcinoma Examined Using Gd-EOB-DTPA Enhanced Hepatic Magnetic Resonance Imaging. PLoS One 2016; 11:e0167155. [PMID: 27907063 PMCID: PMC5132228 DOI: 10.1371/journal.pone.0167155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 11/09/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Proton beam therapy (PBT) achieves good local control for hepatocellular carcinoma (HCC), and toxicity tends to be lower than for photon radiotherapy. Focal liver parenchymal damage in radiotherapy is described as the focal liver reaction (FLR); the threshold doses (TDs) for FLR in the background liver have been analyzed in stereotactic ablative body radiotherapy and brachytherapy. To develop a safer approach for PBT, both TD and liver volume changes are considered clinically important in predicting the extent of damage before treatment, and subsequently in reducing background liver damage. We investigated appearance time, TDs and volume changes regarding FLR after PBT for HCC. MATERIAL AND METHODS Patients who were treated using PBT and were followed up using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA MRI) after PBT were enrolled. Sixty-eight lesions in 58 patients were eligible for analysis. MRI was acquired at the end of treatment, and at 1, 2, 3 and 6 months after PBT. We defined the FLR as a clearly depicted hypointense area on the hepatobiliary phase of Gd-EOB-DTPA MRI, and we monitored TDs and volume changes in the FLR area and the residual liver outside of the FLR area. RESULTS FLR was depicted in all lesions at 3 months after PBT. In FLR expressed as the 2-Gy equivalent dose (α/β = 3 Gy), TDs did not differ significantly (27.0±6.4 CGE [10 fractions [Fr] vs. 30.5±7.3 CGE [20 Fr]). There were also no correlations between the TDs and clinical factors, and no significant differences between Child-Pugh A and B scores. The volume of the FLR area decreased and the residual liver volume increased, particularly during the initial 3 months. CONCLUSION This study established the FLR dose for liver with HCC, which might be useful in the prediction of remnant liver volume for PBT.
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Zheng Y, Kang Y, Zeidan O, Schreuder N. An end-to-end assessment of range uncertainty in proton therapy using animal tissues. Phys Med Biol 2016; 61:8010-8024. [DOI: 10.1088/0031-9155/61/22/8010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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MRI morphologic alterations after liver SBRT : Direct dose correlation with intermodal matching. Strahlenther Onkol 2016; 192:641-8. [PMID: 27393400 DOI: 10.1007/s00066-016-1013-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 06/15/2016] [Indexed: 12/12/2022]
Abstract
AIM CT morphologic and histopathologic alterations have been reported after SBRT. We analyzed the correlation of MRI morphologic alterations with radiation doses to assess the potential for MRI-based dose-effect correlation in healthy liver tissue. PATIENTS AND METHODS MRI data of 24 patients with liver metastases 7±3 weeks after image-guided SBRT in deep-inspiration breath-hold were retrospectively analyzed. MRI images were intermodally matched to the planning CT and corresponding dose distribution. Absolute doses were converted to EQD2,α/β =x with α/β values of 2, 3 for healthy liver tissue, 8 Gy for modelled predamaged liver tissue and 10 Gy for tumor tissue. RESULTS A central nonenhancing area was observed within the isodose lines of nominally 48.2 ± 15.2 Gy, EQD2Gy/α/β =10 92.5 ± 27.7 Gy. Contrast-enhancement around the central nonenhancing area was observed within the isodose lines of nominally 46.9 ± 15.3 Gy, EQD2Gy/α/β =10 90.5 ± 28.3 Gy. Outside the high-dose volume, in the beam path, characteristic sharply defined, nonblurred MRI morphologic alterations were observed that corresponded with the following isodose lines: T1-intensity changes occurred at isodose lines of nominally 21.9 ± 6.7 Gy (EQD2,α/β =2 42.5 ± 8.7 Gy, EQD2,α/β =3 38.5 ± 7.6 Gy, EQD2,α/β =8 30.2 ±6.3 Gy). T2-hyper/hypointensity was observed within isodose lines of nominally 22.4 ± 6.6 Gy (EQD2,α/β=2 42.7 ± 8.1 Gy, EQD2,α/β=3 38.7 ± 7 Gy; EQD2,α/β=8 30.5 ± 5.9 Gy). CONCLUSIONS Using deformable matching, direct spatial/dosimetric correlation of SBRT-induced changes in liver tissue was possible. In the PTV high-dose region, a central nonenhancing area and peripheral contrast medium accumulation was observed. Beam path doses of 38-42 Gy (EQD2,α/β =2-3) induce characteristic MRI morphologic alterations.
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Crane CH, Koay EJ. Solutions that enable ablative radiotherapy for large liver tumors: Fractionated dose painting, simultaneous integrated protection, motion management, and computed tomography image guidance. Cancer 2016; 122:1974-86. [PMID: 26950735 DOI: 10.1002/cncr.29878] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 12/13/2022]
Abstract
The emergence and success of stereotactic body radiation therapy (SBRT) for the treatment of lung cancer have led to its rapid adoption for liver cancers. SBRT can achieve excellent results for small liver tumors. However, the vast majority of physicians interpret SBRT as meaning doses of radiation (range, 4-20 Gray [Gy]) that may not be ablative but are delivered within about 1 week (ie, in 3-6 fractions). Adherence to this approach has limited the effectiveness of SBRT for large liver tumors (>7 cm) because of the need to reduce doses to meet organ constraints. The prognosis for patients who present with large liver tumors is poor, with a median survival ≤12 months, and most of these patients die from tumor-related liver failure. Herein, the authors present a comprehensive solution to achieve ablative SBRT doses for patients with large liver tumors by using a combination of classic, modern, and novel concepts of radiotherapy: fractionation, dose painting, motion management, image guidance, and simultaneous integrated protection. The authors discuss these concepts in the context of large, inoperable liver tumors and review how this approach can substantially prolong survival for patients, most of whom otherwise have a very poor prognosis and few effective treatment options. Cancer 2016;122:1974-86. © 2016 American Cancer Society.
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Affiliation(s)
- Christopher H Crane
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Eugene J Koay
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
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Baumann M, Overgaard J. Bridging the valley of death: The new Radiotherapy & Oncology section “First in man – Translational innovations in radiation oncology”. Radiother Oncol 2016; 118:217-9. [DOI: 10.1016/j.radonc.2016.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/31/2022]
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Richter C, Pausch G, Barczyk S, Priegnitz M, Keitz I, Thiele J, Smeets J, Stappen FV, Bombelli L, Fiorini C, Hotoiu L, Perali I, Prieels D, Enghardt W, Baumann M. First clinical application of a prompt gamma based in vivo proton range verification system. Radiother Oncol 2016; 118:232-7. [DOI: 10.1016/j.radonc.2016.01.004] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/13/2015] [Accepted: 01/05/2016] [Indexed: 12/25/2022]
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Affiliation(s)
- Joao Seco
- a Radiation Oncology, Massachusetts General Hospital and Harvard Medical School , Boston , MA , USA
| | - Maria Francesca Spadea
- b Department of Experimental and Clinical Medicine , Magna Graecia University , Catanzaro , Italy
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Hansen DC, Seco J, Sørensen TS, Petersen JBB, Wildberger JE, Verhaegen F, Landry G. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark. Acta Oncol 2015. [PMID: 26219959 DOI: 10.3109/0284186x.2015.1061212] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. MATERIAL AND METHODS A CT calibration phantom and an abdomen cross section phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling of detectors and the corresponding noise characteristics. Stopping power maps were calculated for all three scans, and compared with the ground truth stopping power from the phantoms. RESULTS Proton CT gave slightly better stopping power estimates than the dual energy CT method, with root mean square errors of 0.2% and 0.5% (for each phantom) compared to 0.5% and 0.9%. Single energy CT root mean square errors were 2.7% and 1.6%. Maximal errors for proton, dual energy and single energy CT were 0.51%, 1.7% and 7.4%, respectively. CONCLUSION Better stopping power estimates could significantly reduce the range errors in proton therapy, but requires a large improvement in current methods which may be achievable with proton CT.
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Affiliation(s)
- David C Hansen
- a Department of Oncology , Aarhus University Hospital , Aarhus , Denmark
| | - Joao Seco
- b Massachussetts General Hospital and Harvard Medical School , Boston , USA
| | | | | | - Joachim E Wildberger
- e Department of Radiology , Maastricht University Medical Center (MUMC) , The Netherlands
| | - Frank Verhaegen
- f Department of Radiation Oncology (MAASTRO) , Maastricht University Medical Center (MUMC) , Maastricht , the Netherlands
- g Medical Physics Unit, Department of Oncology , McGill University , Canada
| | - Guillaume Landry
- f Department of Radiation Oncology (MAASTRO) , Maastricht University Medical Center (MUMC) , Maastricht , the Netherlands
- h Faculty of Physics, Department of Medical Physics , Ludwig-Maximilians-University , Munich , Germany
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Merkle EM, Zech CJ, Bartolozzi C, Bashir MR, Ba-Ssalamah A, Huppertz A, Lee JM, Ricke J, Sakamoto M, Sirlin CB, Ye SL, Zeng M. Consensus report from the 7th International Forum for Liver Magnetic Resonance Imaging. Eur Radiol 2015; 26:674-82. [PMID: 26070500 PMCID: PMC4747985 DOI: 10.1007/s00330-015-3873-2] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/21/2015] [Accepted: 06/02/2015] [Indexed: 12/13/2022]
Abstract
Objectives Liver-specific MRI is a fast-growing field, with technological and protocol advancements providing more robust imaging and allowing a greater depth of information per examination. This article reports the evidence for, and expert thinking on, current challenges in liver-specific MRI, as discussed at the 7th International Forum for Liver MRI, which was held in Shanghai, China, in October 2013. Methods Topics discussed included the role of gadoxetic acid-enhanced MRI in the differentiation of focal nodular hyperplasia from hepatocellular adenoma and small hepatocellular carcinoma (HCC) from small intrahepatic cholangiocarcinoma (in patients with chronic liver disease), the differentiation of low-grade dysplastic nodule (DN) from pre-malignant high-grade DN and early HCC, and treatment planning and assessment of treatment response for patients with HCC and colorectal liver metastasis. Optimization of the gadoxetic acid-enhanced MRI protocol to gain robust arterial and hepatobiliary phase images was also discussed. Results and conclusions Gadoxetic acid-enhanced MRI demonstrates added value for the detection and characterization of focal liver lesions and shows promise in a number of new indications, including regional liver functional assessment and patient monitoring after therapy; however, more data are needed in some areas, and further developments are needed to translate cutting-edge techniques into clinical practice. Key Points • Liver-specific MRI is a fast-growing field, with many technological and protocol advancements. • Gadoxetic acid-enhanced MRI demonstrates value for detecting and characterizing focal liver lesions. • Gadoxetic acid-enhanced MRI shows promise in regional functional assessment and patient monitoring. • Further developments are needed to translate cutting-edge techniques into clinical practice.
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Affiliation(s)
- Elmar M Merkle
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Petersgraben 4, CH-4031, Basel, Switzerland.
| | - Christoph J Zech
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Petersgraben 4, CH-4031, Basel, Switzerland
| | | | - Mustafa R Bashir
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Ahmed Ba-Ssalamah
- Department of General and Pediatric Radiology, Medical University of Vienna, Vienna, Austria
| | | | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul, South Korea
| | - Jens Ricke
- Department of Radiology and Nuclear Medicine, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Michiie Sakamoto
- Department of Pathology, Keio University School of Medicine, Tokyo, Japan
| | - Claude B Sirlin
- Liver Imaging Group, Department of Radiology, University of California, San Diego, California, USA
| | - Sheng-Long Ye
- Department of Hepatic Oncology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Mengsu Zeng
- Radiologic Diagnostic Department, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
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Abstract
Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed "pencil beams" of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak-the characteristic peak of dose at the end of range-combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose "painting" within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the highest level of accuracy and pioneered volumetric treatment planning and imaging at a level of quality now standard in X-ray therapy. IMPT requires not only the highest precision tools but also the highest level of system integration of the services required to deliver high-precision radiotherapy.
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Affiliation(s)
- H M Kooy
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - C Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Seidensticker M, Burak M, Kalinski T, Garlipp B, Koelble K, Wust P, Antweiler K, Seidensticker R, Mohnike K, Pech M, Ricke J. Radiation-induced liver damage: correlation of histopathology with hepatobiliary magnetic resonance imaging, a feasibility study. Cardiovasc Intervent Radiol 2014; 38:213-21. [PMID: 24610229 DOI: 10.1007/s00270-014-0872-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 01/27/2014] [Indexed: 01/26/2023]
Abstract
PURPOSE Radiotherapy of liver malignancies shows promising results (radioembolization, stereotactic irradiation, interstitial brachytherapy). Regardless of the route of application, a certain amount of nontumorous liver parenchyma will be collaterally damaged by radiation. The functional reserve may be significantly reduced with an impact on further treatment planning. Monitoring of radiation-induced liver damage by imaging is neither established nor validated. We performed an analysis to correlate the histopathological presence of radiation-induced liver damage with functional magnetic resonance imaging (MRI) utilizing hepatobiliary contrast media (Gd-BOPTA). METHODS Patients undergoing local high-dose-rate brachytherapy for whom a follow-up hepatobiliary MRI within 120 days after radiotherapy as well as an evaluable liver biopsy from radiation-exposed liver tissue within 7 days before MRI were retrospectively identified. Planning computed tomography (CT)/dosimetry was merged to the CT-documentation of the liver biopsy and to the MRI. Presence/absence of radiation-induced liver damage (histopathology) and Gd-BOPTA uptake (MRI) as well as the dose applied during brachytherapy at the site of tissue sampling was determined. RESULTS Fourteen biopsies from eight patients were evaluated. In all cases with histopathological evidence of radiation-induced liver damage (n = 11), no uptake of Gd-BOPTA was seen. In the remaining three, cases no radiation-induced liver damage but Gd-BOPTA uptake was seen. Presence of radiation-induced liver damage and absence of Gd-BOPTA uptake was correlated with a former high-dose exposition. CONCLUSIONS Absence of hepatobiliary MRI contrast media uptake in radiation-exposed liver parenchyma may indicate radiation-induced liver damage. Confirmatory studies are warranted.
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Affiliation(s)
- Max Seidensticker
- Klinik für Radiologie und Nuklearmedizin, Universitätsklinik Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany,
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Abstract
Protons are an interesting modality for radiotherapy because of their well defined range and favourable depth dose characteristics. On the other hand, these same characteristics lead to added uncertainties in their delivery. This is particularly the case at the distal end of proton dose distributions, where the dose gradient can be extremely steep. In practice however, this gradient is rarely used to spare critical normal tissues due to such worries about its exact position in the patient. Reasons for this uncertainty are inaccuracies and non-uniqueness of the calibration from CT Hounsfield units to proton stopping powers, imaging artefacts (e.g. due to metal implants) and anatomical changes of the patient during treatment. In order to improve the precision of proton therapy therefore, it would be extremely desirable to verify proton range in vivo, either prior to, during, or after therapy. In this review, we describe and compare state-of-the art in vivo proton range verification methods currently being proposed, developed or clinically implemented.
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