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Borja-Lloret M, Barrientos L, Bernabéu J, Lacasta C, Muñoz E, Ros A, Roser J, Viegas R, Llosá G. Influence of the background in Compton camera images for proton therapy treatment monitoring. Phys Med Biol 2023; 68:144001. [PMID: 37339665 DOI: 10.1088/1361-6560/ace024] [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: 06/20/2023] [Indexed: 06/22/2023]
Abstract
Objective. Background events are one of the most relevant contributions to image degradation in Compton camera imaging for hadron therapy treatment monitoring. A study of the background and its contribution to image degradation is important to define future strategies to reduce the background in the system.Approach. In this simulation study, the percentage of different kinds of events and their contribution to the reconstructed image in a two-layer Compton camera have been evaluated. To this end, GATE v8.2 simulations of a proton beam impinging on a PMMA phantom have been carried out, for different proton beam energies and at different beam intensities.Main results. For a simulated Compton camera made of Lanthanum (III) Bromide monolithic crystals, coincidences caused by neutrons arriving from the phantom are the most common type of background produced by secondary radiations in the Compton camera, causing between 13% and 33% of the detected coincidences, depending on the beam energy. Results also show that random coincidences are a significant cause of image degradation at high beam intensities, and their influence in the reconstructed images is studied for values of the time coincidence windows from 500 ps to 100 ns.Significance. Results indicate the timing capabilities required to retrieve the fall-off position with good precision. Still, the noise observed in the image when no randoms are considered make us consider further background rejection methods.
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Affiliation(s)
- M Borja-Lloret
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - L Barrientos
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - J Bernabéu
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - C Lacasta
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - E Muñoz
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - A Ros
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - J Roser
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - R Viegas
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
| | - G Llosá
- Institut de Física Corpuscular (IFIC), CSIC-UV, València, Spain
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2
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Giacomo SD, Utica G, Carminati M, Borghi G, Picciotto A, Fiorini C. Timing Performances of SDD as Photodetector Candidate for Proton Therapy Application. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022. [DOI: 10.1109/trpms.2021.3137668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- S. Di Giacomo
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - G. Utica
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - M. Carminati
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - G. Borghi
- Integrated Radiation and Image Sensors, Fondazione Bruno Kessler, Trento, Italy
| | - A. Picciotto
- Integrated Radiation and Image Sensors, Fondazione Bruno Kessler, Trento, Italy
| | - C. Fiorini
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
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3
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Compton imaging for medical applications. Radiol Phys Technol 2022; 15:187-205. [PMID: 35867197 DOI: 10.1007/s12194-022-00666-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 12/18/2022]
Abstract
Compton imaging exploits inelastic scattering, known as Compton scattering, using a Compton camera consisting of a scatterer detector in the front layer and an absorber detector in the back layer. This method was developed for astronomy, and in recent years, research and development for environmental and medical applications has been actively conducted. Compton imaging can discriminate gamma rays over a wide energy range from several hundred keV to several MeV. Therefore, it is expected to be applied to the simultaneous imaging of multiple nuclides in nuclear medicine and prompt gamma ray imaging for range verification in particle therapy. In addition, multiple gamma coincidence imaging is expected to be realized, which allows the source position to be determined from a single coincidence event using nuclides that emit multiple gamma rays simultaneously, such as nuclides that emit a single gamma ray simultaneously with positron decay. This review introduces various efforts toward the practical application of Compton imaging in the medical field, including in vivo studies, and discusses its prospects.
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Valencia Lozano I, Dedes G, Peterson S, Mackin D, Zoglauer A, Beddar S, Avery S, Polf J, Parodi K. Comparison of reconstructed prompt gamma emissions using maximum likelihood estimation and origin ensemble algorithms for a Compton camera system tailored to proton range monitoring. Z Med Phys 2022:S0939-3889(22)00060-5. [PMID: 35750591 DOI: 10.1016/j.zemedi.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 10/18/2022]
Abstract
Compton-based prompt gamma (PG) imaging is being investigated by several groups as a potential solution for in vivo range monitoring in proton therapy. The performance of this technique depends on the detector system as well as the ability of the reconstruction method to obtain good spatial resolution to establish a quantitative correlation between the PG emission and the proton beam range in the patient. To evaluate the feasibility of PG imaging for range monitoring, we quantitatively evaluated the emission distributions reconstructed by a Maximum Likelihood Expectation Maximization (MLEM) and a Stochastic Origin Ensemble (SOE) algorithm. To this end, we exploit experimental and Monte Carlo (MC) simulation data acquired with the Polaris-J Compton Camera (CC) prototype. The differences between the proton beam range (RD) defined as the 80% distal dose fall-off and the PG range (RPG), obtained by fitting the distal end of the reconstructed profile with a sigmoid function, were quantified. A comparable performance of both reconstruction algorithms was found. For both experimental and simulated irradiation scenarios, the correlation between RD and RPG was within 5 mm. These values were consistent with the ground truth distance (RD-RPGg≈ 3 mm) calculated by using the expected PG emission available from MC simulation. Furthermore, shifts of 3 mm in the proton beam range were resolved with the MLEM algorithm by calculating the relative difference between the RPG for each reconstructed profile. In non-homogeneous targets, the spatial changes in the PG emission due to the different materials could not be fully resolved from the reconstructed profiles; however, the fall-off region still resembled the ground truth emission. For this scenario, the PG correlation (RD-RPG) varied from 0.1 mm to 4 mm, which is close to the ground truth correlation (3 mm). This work provides a framework for the evaluation of the range monitoring capabilities of a CC device for PG imaging. The two investigated image reconstruction algorithms showed a comparable and consistent performance for homogeneous and heterogeneous targets.
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Affiliation(s)
- Ingrid Valencia Lozano
- Department of Medical Physics, Ludwig-Maximilians-Universität, Garching b. München, Germany.
| | - George Dedes
- Department of Medical Physics, Ludwig-Maximilians-Universität, Garching b. München, Germany
| | - Steve Peterson
- Department of Physics, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Dennis Mackin
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Andreas Zoglauer
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Sam Beddar
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Stephen Avery
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jerimy Polf
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Katia Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität, Garching b. München, Germany
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5
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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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6
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Towards machine learning aided real-time range imaging in proton therapy. Sci Rep 2022; 12:2735. [PMID: 35177663 PMCID: PMC8854574 DOI: 10.1038/s41598-022-06126-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 01/20/2022] [Indexed: 11/08/2022] Open
Abstract
Compton imaging represents a promising technique for range verification in proton therapy treatments. In this work, we report on the advantageous aspects of the i-TED detector for proton-range monitoring, based on the results of the first Monte Carlo study of its applicability to this field. i-TED is an array of Compton cameras, that have been specifically designed for neutron-capture nuclear physics experiments, which are characterized by [Formula: see text]-ray energies spanning up to 5-6 MeV, rather low [Formula: see text]-ray emission yields and very intense neutron induced [Formula: see text]-ray backgrounds. Our developments to cope with these three aspects are concomitant with those required in the field of hadron therapy, especially in terms of high efficiency for real-time monitoring, low sensitivity to neutron backgrounds and reliable performance at the high [Formula: see text]-ray energies. We find that signal-to-background ratios can be appreciably improved with i-TED thanks to its light-weight design and the low neutron-capture cross sections of its LaCl[Formula: see text] crystals, when compared to other similar systems based on LYSO, CdZnTe or LaBr[Formula: see text]. Its high time-resolution (CRT [Formula: see text] 500 ps) represents an additional advantage for background suppression when operated in pulsed HT mode. Each i-TED Compton module features two detection planes of very large LaCl[Formula: see text] monolithic crystals, thereby achieving a high efficiency in coincidence of 0.2% for a point-like 1 MeV [Formula: see text]-ray source at 5 cm distance. This leads to sufficient statistics for reliable image reconstruction with an array of four i-TED detectors assuming clinical intensities of 10[Formula: see text] protons per treatment point. The use of a two-plane design instead of three-planes has been preferred owing to the higher attainable efficiency for double time-coincidences than for threefold events. The loss of full-energy events for high energy [Formula: see text]-rays is compensated by means of machine-learning based algorithms, which allow one to enhance the signal-to-total ratio up to a factor of 2.
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7
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Multi-modal 3D imaging of radionuclides using multiple hybrid Compton cameras. Sci Rep 2022; 12:2546. [PMID: 35169183 PMCID: PMC8847431 DOI: 10.1038/s41598-022-06401-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/28/2022] [Indexed: 12/25/2022] Open
Abstract
For radiological diagnosis and radionuclide therapy, X-ray and gamma-ray imaging technologies are essential. Single-photon emission tomography (SPECT) and positron emission tomography (PET) play essential roles in radiological diagnosis, such as the early detection of tumors. Radionuclide therapy is also rapidly developing with the use of these modalities. Nevertheless, a limited number of radioactive tracers are imaged owing to the limitations of the imaging devices. In a previous study, we developed a hybrid Compton camera that conducts simultaneous Compton and pinhole imaging within a single system. In this study, we developed a system that simultaneously realizes three modalities: Compton, pinhole, and PET imaging in 3D space using multiple hybrid Compton cameras. We achieved the simultaneous imaging of Cs-137 (Compton mode targeting 662 keV), Na-22 (PET mode targeting 511 keV), and Am-241 (pinhole mode targeting 60 keV) within the same field of view. In addition, the imaging of Ga-67 and In-111, which are used in various diagnostic scenarios, was conducted. We also verified that the 3D distribution of the At-211 tracer inside a mouse could be imaged using the pinhole mode.
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8
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Livingstone J, Dauvergne D, Etxebeste A, Fontana M, Gallin-Martel ML, Huisman B, Létang JM, Marcatili S, Sarrut D, Testa É. Influence of sub-nanosecond time of flight resolution for online range verification in proton therapy using the line-cone reconstruction in Compton imaging. Phys Med Biol 2021; 66. [PMID: 34020434 DOI: 10.1088/1361-6560/ac03cb] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 05/21/2021] [Indexed: 11/11/2022]
Abstract
Online ion range monitoring in hadron therapy can be performed via detection of secondary radiation, such as promptγ-rays, emitted during treatment. The promptγemission profile is correlated with the ion depth-dose profile and can be reconstructed via Compton imaging. The line-cone reconstruction, using the intersection between the primary beam trajectory and the cone reconstructed via a Compton camera, requires negligible computation time compared to iterative algorithms. A recent report hypothesised that time of flight (TOF) based discrimination could improve the precision of theγfall-off position (FOP) measured via line-cone reconstruction, where TOF comprises both the proton transit time from the phantom entrance untilγemission, and the flight time of theγ-ray to the detector. The aim of this study was to implement such a method and investigate the influence of temporal resolution on the precision of the FOP. Monte Carlo simulations of a 160 MeV proton beam incident on a homogeneous PMMA phantom were performed using GATE. The Compton camera consisted of a silicon-based scatterer and CeBr3scintillator absorber. The temporal resolution of the detection system (absorber + beam trigger) was varied between 0.1 and 1.3 ns rms and a TOF-based discrimination method applied to eliminate unlikely solution(s) from the line-cone reconstruction. The FOP was obtained for varying temporal resolutions and its precision obtained from its shift across 100 independentγemission profiles compared to a high statistics reference profile. The optimal temporal resolution for the given camera geometry and 108primary protons was 0.2 ns where a precision of 2.30 ± 0.15 mm (1σ) on the FOP was found. This precision is comparable to current state-of-the-art Compton imaging using iterative reconstruction methods or 1D imaging with mechanically collimated devices, and satisfies the requirement of being smaller than the clinical safety margins.
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Affiliation(s)
- Jayde Livingstone
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique des 2 Infinis, F-69622 Villeurbanne, France.,Université Grenoble Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, F-38026 Grenoble, France
| | - Denis Dauvergne
- Université Grenoble Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, F-38026 Grenoble, France
| | - Ane Etxebeste
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69373 Lyon, France
| | - Mattia Fontana
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique des 2 Infinis, F-69622 Villeurbanne, France
| | - Marie-Laure Gallin-Martel
- Université Grenoble Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, F-38026 Grenoble, France
| | - Brent Huisman
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69373 Lyon, France
| | - Jean Michel Létang
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69373 Lyon, France
| | - Sara Marcatili
- Université Grenoble Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, F-38026 Grenoble, France
| | - David Sarrut
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69373 Lyon, France
| | - Étienne Testa
- Université Grenoble Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, F-38026 Grenoble, France
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9
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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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Feng Y, Etxebeste A, Sarrut D, Letang JM, Maxim V. 3-D Reconstruction Benchmark of a Compton Camera Against a Parallel-Hole Gamma Camera on Ideal Data. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020. [DOI: 10.1109/trpms.2019.2955745] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Carlier B, Heymans SV, Nooijens S, Toumia Y, Ingram M, Paradossi G, D’Agostino E, Himmelreich U, D’hooge J, Van Den Abeele K, Sterpin E. Proton range verification with ultrasound imaging using injectable radiation sensitive nanodroplets: a feasibility study. ACTA ACUST UNITED AC 2020; 65:065013. [DOI: 10.1088/1361-6560/ab7506] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Hueso-González F, Bortfeld T. Compact Method for Proton Range Verification Based on Coaxial Prompt Gamma-Ray Monitoring: a Theoretical Study. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020; 4:170-183. [PMID: 32258856 PMCID: PMC7111431 DOI: 10.1109/trpms.2019.2930362] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Range uncertainties in proton therapy hamper treatment precision. Prompt gamma-rays were suggested 16 years ago for real-time range verification, and have already shown promising results in clinical studies with collimated cameras. Simultaneously, alternative imaging concepts without collimation are investigated to reduce the footprint and price of current prototypes. In this manuscript, a compact range verification method is presented. It monitors prompt gamma-rays with a single scintillation detector positioned coaxially to the beam and behind the patient. Thanks to the solid angle effect, proton range deviations can be derived from changes in the number of gamma-rays detected per proton, provided that the number of incident protons is well known. A theoretical background is formulated and the requirements for a future proof-of-principle experiment are identified. The potential benefits and disadvantages of the method are discussed, and the prospects and potential obstacles for its use during patient treatments are assessed. The final milestone is to monitor proton range differences in clinical cases with a statistical precision of 1 mm, a material cost of 25000 USD and a weight below 10 kg. This technique could facilitate the widespread application of in vivo range verification in proton therapy and eventually the improvement of treatment quality.
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Affiliation(s)
- F Hueso-González
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
| | - T Bortfeld
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
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13
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Nakano T, Sakai M, Torikai K, Suzuki Y, Takeda S, Noda SE, Yamaguchi M, Nagao Y, Kikuchi M, Odaka H, Kamiya T, Kawachi N, Watanabe S, Arakawa K, Takahashi T. Imaging of 99mTc-DMSA and 18F-FDG in humans using a Si/CdTe Compton camera. ACTA ACUST UNITED AC 2020; 65:05LT01. [DOI: 10.1088/1361-6560/ab33d8] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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14
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Etxebeste A, Dauvergne D, Fontana M, Létang JM, Llosá G, Munoz E, Oliver JF, Testa É, Sarrut D. CCMod: a GATE module for Compton camera imaging simulation. Phys Med Biol 2020; 65:055004. [DOI: 10.1088/1361-6560/ab6529] [Citation(s) in RCA: 10] [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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15
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Muñoz E, Barrientos L, Bernabéu J, Borja-Lloret M, Llosá G, Ros A, Roser J, Oliver JF. A spectral reconstruction algorithm for two-plane Compton cameras. Phys Med Biol 2020; 65:025011. [PMID: 31739295 DOI: 10.1088/1361-6560/ab58ad] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
One factor limiting the current applicability extent of hadron therapy is the lack of a reliable method for real time treatment monitoring. The use of Compton imaging systems as monitors requires the correct reconstruction of the distribution of prompt gamma productions during patient irradiation. In order to extract the maximum information from all the measurable events, we implemented a spectral reconstruction method that assigns to all events a probability of being either partial or total energy depositions. The method, implemented in a list-mode maximum likelihood expectation maximization algorithm, generates a four dimensional image in the joint spatial-spectral domain, in which the voxels containing the emission positions and energies are obtained. The analytical model used for the system response function is also employed to derive an analytical expression for the sensitivity, which is calculated via Monte Carlo integration. The performance of the method is evaluated through reconstruction of various experimental and simulated sources with different spatial and energy distributions. The results show that the proposed method can recover the spectral and spatial information simultaneously, but only under the assumption of ideal measurements. The analysis of the Monte Carlo simulations has led to the identification of two important degradation sources: the mispositioning of the gamma interaction point and the missing energy recorded in the interaction. Both factors are related to the high energy transferred to the recoil electrons, which can travel far from the interaction point and even escape the detector. These effects prevent the direct application of the current method in more realistic scenarios. Nevertheless, experimental point-like sources have been accurately reconstructed and the spatial distributions and spectral emission of complex simulated phantoms can be identified.
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Affiliation(s)
- Enrique Muñoz
- Instituto de Física Corpuscular, CSIC/Universitat de València, Valencia, Spain
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Panaino CMV, Mackay RI, Kirkby KJ, Taylor MJ. A New Method to Reconstruct in 3D the Emission Position of the Prompt Gamma Rays following Proton Beam Irradiation. Sci Rep 2019; 9:18820. [PMID: 31827167 PMCID: PMC6906450 DOI: 10.1038/s41598-019-55349-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 11/26/2019] [Indexed: 01/18/2023] Open
Abstract
A new technique for range verification in proton beam therapy has been developed. It is based on the detection of the prompt γ rays that are emitted naturally during the delivery of the treatment. A spectrometer comprising 16 LaBr3(Ce) detectors in a symmetrical configuration is employed to record the prompt γ rays emitted along the proton path. An algorithm has been developed that takes as inputs the LaBr3(Ce) detector signals and reconstructs the maximum γ-ray intensity peak position, in full 3 dimensions. For a spectrometer radius of 8 cm, which could accommodate a paediatric head and neck case, the prompt γ-ray origin can be determined from the width of the detected peak with a σ of 4.17 mm for a 180 MeV proton beam impinging a water phantom. For spectrometer radii of 15 and 25 cm to accommodate larger volumes this value increases to 5.65 and 6.36 mm. For a 8 cm radius, with a 5 and 10 mm undershoot, the σ is 4.31 and 5.47 mm. These uncertainties are comparable to the range uncertainties incorporated in treatment planning. This work represents the first step towards a new accurate, real-time, 3D range verification device for spot-scanning proton beam therapy.
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Affiliation(s)
- Costanza M V Panaino
- Division of Cancer Sciences, University of Manchester, M13 9PL, Manchester, UK. .,The Christie NHS Foundation Trust, M20 4BX, Manchester, UK.
| | - Ranald I Mackay
- Division of Cancer Sciences, University of Manchester, M13 9PL, Manchester, UK.,The Christie NHS Foundation Trust, M20 4BX, Manchester, UK
| | - Karen J Kirkby
- Division of Cancer Sciences, University of Manchester, M13 9PL, Manchester, UK.,The Christie NHS Foundation Trust, M20 4BX, Manchester, UK
| | - Michael J Taylor
- Division of Cancer Sciences, University of Manchester, M13 9PL, Manchester, UK.,The Christie NHS Foundation Trust, M20 4BX, Manchester, UK
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Zarifi M, Guatelli S, Qi Y, Bolst D, Prokopovich D, Rosenfeld A. Characterization of prompt gamma ray emission for in vivo range verification in particle therapy: A simulation study. Phys Med 2019; 62:20-32. [DOI: 10.1016/j.ejmp.2019.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/15/2019] [Accepted: 04/24/2019] [Indexed: 11/27/2022] Open
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Hueso-González F, Rabe M, Ruggieri TA, Bortfeld T, Verburg JM. A full-scale clinical prototype for proton range verification using prompt gamma-ray spectroscopy. Phys Med Biol 2018; 63:185019. [PMID: 30033938 PMCID: PMC6340397 DOI: 10.1088/1361-6560/aad513] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present a full-scale clinical prototype system for in vivo range verification of proton pencil-beams using the prompt gamma-ray spectroscopy method. The detection system consists of eight LaBr3 scintillators and a tungsten collimator, mounted on a rotating frame. Custom electronics and calibration algorithms have been developed for the measurement of energy- and time-resolved gamma-ray spectra during proton irradiation at a clinical dose rate. Using experimentally determined nuclear reaction cross sections and a GPU-accelerated Monte Carlo simulation, a detailed model of the expected gamma-ray emissions is created for each individual pencil-beam. The absolute range of the proton pencil-beams is determined by minimizing the discrepancy between the measurement and this model, leaving the absolute range of the beam and the elemental concentrations of the irradiated matter as free parameters. The system was characterized in a clinical-like situation by irradiating different phantoms with a scanning pencil-beam. A dose of 0.9 Gy was delivered to a [Formula: see text] cm3 target with a beam current of 2 nA incident on the phantom. Different range shifters and materials were used to test the robustness of the verification method and to calculate the accuracy of the detected range. The absolute proton range was determined for each spot of the distal energy layer with a mean statistical precision of 1.1 mm at a 95% confidence level and a mean systematic deviation of 0.5 mm, when aggregating pencil-beam spots within a cylindrical region of 10 mm radius and 10 mm depth. Small range errors that we introduced were successfully detected and even large differences in the elemental composition do not affect the range verification accuracy. These results show that our system is suitable for range verification during patient treatments in our upcoming clinical study.
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Affiliation(s)
- Fernando Hueso-González
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, United States of America
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Draeger E, Mackin D, Peterson S, Chen H, Avery S, Beddar S, Polf JC. 3D prompt gamma imaging for proton beam range verification. Phys Med Biol 2018; 63:035019. [PMID: 29380750 DOI: 10.1088/1361-6560/aaa203] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We tested the ability of a single Compton camera (CC) to produce 3-dimensional (3D) images of prompt gammas (PGs) emitted during the irradiation of a tissue-equivalent plastic phantom with proton pencil beams for clinical doses delivered at clinical dose rates. PG measurements were made with a small prototype CC placed at three different locations along the proton beam path. We evaluated the ability of the CC to produce images at each location for two clinical scenarios: (1) the delivery of a single 2 Gy pencil beam from a hypo-fractionated treatment (~9 × 108 protons), and (2) a single pencil beam from a standard treatment (~1 × 108 protons). Additionally, the data measured at each location were combined to simulate measurements with a larger scale, clinical CC and its ability to image shifts in the Bragg peak (BP) range for both clinical scenarios. With our prototype CC, the location of the distal end of the BP could be seen with the CC placed up to 4 cm proximal or distal to the BP distal falloff. Using the data from the simulated full scale clinical CC, 3D images of the PG emission were produced with the delivery of as few as 1 × 108 protons, and shifts in the proton beam range as small as 2 mm could be detected for delivery of a 2 Gy spot. From these results we conclude that 3D PG imaging for proton range verification under clinical beam delivery conditions is possible with a single CC.
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Affiliation(s)
- E Draeger
- Department of Radiation Oncology, University of Maryland School of Medicine, 22 South Greene St., Baltimore, MD 21201, United States of America
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