The Experts below are selected from a list of 11532 Experts worldwide ranked by ideXlab platform
Takashi Nakano - One of the best experts on this subject based on the ideXlab platform.
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Use of a Si/CdTe Compton Camera for In vivo Real-Time Monitoring of Annihilation Gamma Rays Generated by Carbon Ion Beam Irradiation.
Frontiers in oncology, 2020Co-Authors: Shintaro Shiba, Raj Kumar Parajuli, Makoto Sakai, Takahiro Oike, Tatsuya Ohno, Takashi NakanoAbstract:The application of Annihilation Gamma-Ray monitoring to the adaptive therapy of carbon ion radiotherapy (C-ion RT) requires identification of the peak intensity position and confirmation of activated elements with Annihilation Gamma-Rays generated at the C-ion-irradiated site from those transported to unirradiated sites. Real-time monitoring of C-ion-induced Annihilation Gamma-Rays was implemented using a Compton camera in a mouse model. An adult C57BL/6 mouse was anesthetized, and C-ion beams were directed into the abdomen at 1 × 109 particles/s for 20 s. The 511 keV Annihilation Gamma-Rays, generated by the interaction between the irradiated C-ion beam and the target mouse, were detected using a silicon/cadmium telluride (Si/CdTe) Compton camera for 20 min immediately after irradiation. The irradiated site and the peak intensity position of 511 keV Gamma emissions due to C-ion beam irradiation on a mouse were observed at the abdomen of the mouse by developing Compton images. Moreover, the positron emitter transport was observed by evaluating the range of Gamma-Ray emission after the C-ion beam irradiation on the mouse. Our data suggest that by confirming the peak intensity and beam range of C-ion RT with Si/CdTe-based Compton camera, it would be possible to reduce the intra-fractional and inter-fractional dose distribution degradation. Therefore, the results of this study would contribute to the future development of adaptive therapy with C-ion RT for humans.
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Annihilation Gamma imaging for carbon ion beam range monitoring using Si/CdTe Compton camera.
Physics in medicine and biology, 2019Co-Authors: Raj Kumar Parajuli, Makoto Sakai, Wataru Kada, Kota Torikai, Mikiko Kikuchi, Kazuo Arakawa, Masami Torikoshi, Takashi NakanoAbstract:In this study, we performed on-beam monitoring of 511 keV Annihilation Gamma emissions using a Compton camera. Beam monitoring experiments were conducted using carbon ion beams of 290 MeV/u irradiated on a polymethyl methacrylate (PMMA) phantom. The intensity of the beams was 3 × 109 particles per pulse, with 20 pulses per minute. A Compton camera based on a silicon/cadmium telluride (Si/CdTe) detector was used to monitor the Annihilation Gamma Rays emitted from the phantom. We successfully reconstructed the energy events of 511 keV Annihilation Gamma Rays and developed Compton images using a simple back-projection method. The distribution of the Annihilation Gamma Ray generation traced the beam trajectory and the peak intensity position was a few millimeters shorter than the Bragg peak position. Moreover, the effect of the beam range shifter with 30, 60, and 90 mm water equivalent thickness (WET) was clearly visualized in the reconstructed Compton images. The experimentally measured values of the corresponding range shifts in the PMMA phantom (28.70 mm, 52.49 mm, and 76.77 mm, respectively) were consistent with the shifts of the Bragg peak position (25.50 mm, 51.30 mm and 76.70 mm, respectively) evaluated by Monte Carlo simulation. The results show that the Si/CdTe Compton camera has strong potential for on-beam monitoring of Annihilation Gamma Rays in particle therapy in clinical situations.
Raj Kumar Parajuli - One of the best experts on this subject based on the ideXlab platform.
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Use of a Si/CdTe Compton Camera for In vivo Real-Time Monitoring of Annihilation Gamma Rays Generated by Carbon Ion Beam Irradiation.
Frontiers in oncology, 2020Co-Authors: Shintaro Shiba, Raj Kumar Parajuli, Makoto Sakai, Takahiro Oike, Tatsuya Ohno, Takashi NakanoAbstract:The application of Annihilation Gamma-Ray monitoring to the adaptive therapy of carbon ion radiotherapy (C-ion RT) requires identification of the peak intensity position and confirmation of activated elements with Annihilation Gamma-Rays generated at the C-ion-irradiated site from those transported to unirradiated sites. Real-time monitoring of C-ion-induced Annihilation Gamma-Rays was implemented using a Compton camera in a mouse model. An adult C57BL/6 mouse was anesthetized, and C-ion beams were directed into the abdomen at 1 × 109 particles/s for 20 s. The 511 keV Annihilation Gamma-Rays, generated by the interaction between the irradiated C-ion beam and the target mouse, were detected using a silicon/cadmium telluride (Si/CdTe) Compton camera for 20 min immediately after irradiation. The irradiated site and the peak intensity position of 511 keV Gamma emissions due to C-ion beam irradiation on a mouse were observed at the abdomen of the mouse by developing Compton images. Moreover, the positron emitter transport was observed by evaluating the range of Gamma-Ray emission after the C-ion beam irradiation on the mouse. Our data suggest that by confirming the peak intensity and beam range of C-ion RT with Si/CdTe-based Compton camera, it would be possible to reduce the intra-fractional and inter-fractional dose distribution degradation. Therefore, the results of this study would contribute to the future development of adaptive therapy with C-ion RT for humans.
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Annihilation Gamma imaging for carbon ion beam range monitoring using Si/CdTe Compton camera.
Physics in medicine and biology, 2019Co-Authors: Raj Kumar Parajuli, Makoto Sakai, Wataru Kada, Kota Torikai, Mikiko Kikuchi, Kazuo Arakawa, Masami Torikoshi, Takashi NakanoAbstract:In this study, we performed on-beam monitoring of 511 keV Annihilation Gamma emissions using a Compton camera. Beam monitoring experiments were conducted using carbon ion beams of 290 MeV/u irradiated on a polymethyl methacrylate (PMMA) phantom. The intensity of the beams was 3 × 109 particles per pulse, with 20 pulses per minute. A Compton camera based on a silicon/cadmium telluride (Si/CdTe) detector was used to monitor the Annihilation Gamma Rays emitted from the phantom. We successfully reconstructed the energy events of 511 keV Annihilation Gamma Rays and developed Compton images using a simple back-projection method. The distribution of the Annihilation Gamma Ray generation traced the beam trajectory and the peak intensity position was a few millimeters shorter than the Bragg peak position. Moreover, the effect of the beam range shifter with 30, 60, and 90 mm water equivalent thickness (WET) was clearly visualized in the reconstructed Compton images. The experimentally measured values of the corresponding range shifts in the PMMA phantom (28.70 mm, 52.49 mm, and 76.77 mm, respectively) were consistent with the shifts of the Bragg peak position (25.50 mm, 51.30 mm and 76.70 mm, respectively) evaluated by Monte Carlo simulation. The results show that the Si/CdTe Compton camera has strong potential for on-beam monitoring of Annihilation Gamma Rays in particle therapy in clinical situations.
Makoto Sakai - One of the best experts on this subject based on the ideXlab platform.
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Use of a Si/CdTe Compton Camera for In vivo Real-Time Monitoring of Annihilation Gamma Rays Generated by Carbon Ion Beam Irradiation.
Frontiers in oncology, 2020Co-Authors: Shintaro Shiba, Raj Kumar Parajuli, Makoto Sakai, Takahiro Oike, Tatsuya Ohno, Takashi NakanoAbstract:The application of Annihilation Gamma-Ray monitoring to the adaptive therapy of carbon ion radiotherapy (C-ion RT) requires identification of the peak intensity position and confirmation of activated elements with Annihilation Gamma-Rays generated at the C-ion-irradiated site from those transported to unirradiated sites. Real-time monitoring of C-ion-induced Annihilation Gamma-Rays was implemented using a Compton camera in a mouse model. An adult C57BL/6 mouse was anesthetized, and C-ion beams were directed into the abdomen at 1 × 109 particles/s for 20 s. The 511 keV Annihilation Gamma-Rays, generated by the interaction between the irradiated C-ion beam and the target mouse, were detected using a silicon/cadmium telluride (Si/CdTe) Compton camera for 20 min immediately after irradiation. The irradiated site and the peak intensity position of 511 keV Gamma emissions due to C-ion beam irradiation on a mouse were observed at the abdomen of the mouse by developing Compton images. Moreover, the positron emitter transport was observed by evaluating the range of Gamma-Ray emission after the C-ion beam irradiation on the mouse. Our data suggest that by confirming the peak intensity and beam range of C-ion RT with Si/CdTe-based Compton camera, it would be possible to reduce the intra-fractional and inter-fractional dose distribution degradation. Therefore, the results of this study would contribute to the future development of adaptive therapy with C-ion RT for humans.
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Annihilation Gamma imaging for carbon ion beam range monitoring using Si/CdTe Compton camera.
Physics in medicine and biology, 2019Co-Authors: Raj Kumar Parajuli, Makoto Sakai, Wataru Kada, Kota Torikai, Mikiko Kikuchi, Kazuo Arakawa, Masami Torikoshi, Takashi NakanoAbstract:In this study, we performed on-beam monitoring of 511 keV Annihilation Gamma emissions using a Compton camera. Beam monitoring experiments were conducted using carbon ion beams of 290 MeV/u irradiated on a polymethyl methacrylate (PMMA) phantom. The intensity of the beams was 3 × 109 particles per pulse, with 20 pulses per minute. A Compton camera based on a silicon/cadmium telluride (Si/CdTe) detector was used to monitor the Annihilation Gamma Rays emitted from the phantom. We successfully reconstructed the energy events of 511 keV Annihilation Gamma Rays and developed Compton images using a simple back-projection method. The distribution of the Annihilation Gamma Ray generation traced the beam trajectory and the peak intensity position was a few millimeters shorter than the Bragg peak position. Moreover, the effect of the beam range shifter with 30, 60, and 90 mm water equivalent thickness (WET) was clearly visualized in the reconstructed Compton images. The experimentally measured values of the corresponding range shifts in the PMMA phantom (28.70 mm, 52.49 mm, and 76.77 mm, respectively) were consistent with the shifts of the Bragg peak position (25.50 mm, 51.30 mm and 76.70 mm, respectively) evaluated by Monte Carlo simulation. The results show that the Si/CdTe Compton camera has strong potential for on-beam monitoring of Annihilation Gamma Rays in particle therapy in clinical situations.
Clifford M Surko - One of the best experts on this subject based on the ideXlab platform.
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Positron Annihilation studies in a Penning trap: Partially fluorinated hydrocarbons
Bulletin of the American Physical Society, 1996Co-Authors: K. Iwata, R. G. Greaves, C. Kurz, Clifford M SurkoAbstract:The accumulation of large numbers of positrons in a Penning trap allows the authors to study two-body interactions of room temperature positrons with atoms and molecules. The authors present results from Annihilation rate and {Gamma}-Ray spectrum measurements performed with a variety of substances. The Annihilation rate measurements indicate the surprising existence of the long-lived positron-molecule compounds. The nature of these states is not understood. The Doppler-broadening of the Annihilation {Gamma}-Ray line measures the center-of-mass momentum distribution of the annihilating positron-electron pair. Their precision measurements of lineshape are compared with the latest theoretical calculations for simple atoms. In partially fluorinated hydrocarbons, multiple Annihilation sites in a molecule have been identified for the first time. Correlation of the {Gamma}-Ray measurements with the measured Annihilation rates is presented. The implications of the new measurements, including interstellar positron Annihilation, will be discussed.
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Annihilation Gamma-Ray spectra from positron-molecule interactions.
Physical review letters, 1992Co-Authors: S. Tang, M. D. Tinkle, R. G. Greaves, Clifford M SurkoAbstract:We report measurements of Annihilation Gamma-Ray spectra from the isolated two-body interaction of room-temperature positrons with a range of chemical species. The Doppler broadening of these spectra provides information about the wave functions of the annihilating particles. For a variety of hydrocarbons, we observe linewidths of approximately 2.2 keV (FWHM), while for perfluorocarbons the widths are approximately 2.8 keV, as compared with 1.7 keV for molecular hydrogen. The implications of these results for a number of physical problems are discussed
Shintaro Shiba - One of the best experts on this subject based on the ideXlab platform.
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Use of a Si/CdTe Compton Camera for In vivo Real-Time Monitoring of Annihilation Gamma Rays Generated by Carbon Ion Beam Irradiation.
Frontiers in oncology, 2020Co-Authors: Shintaro Shiba, Raj Kumar Parajuli, Makoto Sakai, Takahiro Oike, Tatsuya Ohno, Takashi NakanoAbstract:The application of Annihilation Gamma-Ray monitoring to the adaptive therapy of carbon ion radiotherapy (C-ion RT) requires identification of the peak intensity position and confirmation of activated elements with Annihilation Gamma-Rays generated at the C-ion-irradiated site from those transported to unirradiated sites. Real-time monitoring of C-ion-induced Annihilation Gamma-Rays was implemented using a Compton camera in a mouse model. An adult C57BL/6 mouse was anesthetized, and C-ion beams were directed into the abdomen at 1 × 109 particles/s for 20 s. The 511 keV Annihilation Gamma-Rays, generated by the interaction between the irradiated C-ion beam and the target mouse, were detected using a silicon/cadmium telluride (Si/CdTe) Compton camera for 20 min immediately after irradiation. The irradiated site and the peak intensity position of 511 keV Gamma emissions due to C-ion beam irradiation on a mouse were observed at the abdomen of the mouse by developing Compton images. Moreover, the positron emitter transport was observed by evaluating the range of Gamma-Ray emission after the C-ion beam irradiation on the mouse. Our data suggest that by confirming the peak intensity and beam range of C-ion RT with Si/CdTe-based Compton camera, it would be possible to reduce the intra-fractional and inter-fractional dose distribution degradation. Therefore, the results of this study would contribute to the future development of adaptive therapy with C-ion RT for humans.
