Jung-In Kim1,2,3, Hanyoung Lee4, Hong-Gyun Wu1,2,3,5, Eui Kyu Chie1,2,3,5, Hyun-Cheol Kang1,2,3, Jong Min Park1,2,3,6. 1. Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Korea. 2. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Korea. 3. Biomedical Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea. 4. HanBeam Technology, Inc., Seongnam, 463-825, Korea. 5. Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, 03080, Korea. 6. Robotics Research Laboratory for Extreme Environments, Advanced Institutes of Convergence Technology, Suwon, 433-270, Korea.
Abstract
PURPOSE: The aim of this study is to develop a visual guidance patient-controlled (VG-PC) respiratory gating system for respiratory-gated magnetic-resonance image-guided radiation therapy (MR-IGRT) and to evaluate the performance of the developed system. METHODS: The near-real-time cine planar MR image of a patient acquired during treatment was transmitted to a beam projector in the treatment room through an optical fiber cable. The beam projector projected the cine MR images inside the bore of the ViewRay system in order to be visible to a patient during treatment. With this visual information, patients voluntarily controlled their respiration to put the target volume into the gating boundary (gating window). The effect of the presence of the beam projector in the treatment room on the image quality of the MRI was investigated by evaluating the signal-to-noise ratio (SNR), uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity with the VG-PC gating system. To evaluate the performance of the developed system, we applied the VG-PC gating system to a total of seven patients; six patients received stereotactic ablative radiotherapy (SABR) and one patient received conventional fractionated radiation therapy. RESULTS: The projected cine MR images were visible even when the room light was on. No image data loss or additional time delay during delivery of image data were observed. Every indicator representing MRI quality, including SNR, uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity exhibited values higher than the tolerance levels of the manufacturer with the VG-PC gating system; therefore, the presence of the VG-PC gating system in the treatment room did not degrade the MR image quality. The average beam-off times due to respiratory gating with and without the VG-PC gating system were 830.3 ± 278.2 s and 1264.2 ± 302.1 s respectively (P = 0.005). Consequently, the total treatment times excluding the time for patient setup with and without the VG-PC gating system were 1453.3 ± 297.3 s and 1887.2 ± 469.6 s, respectively, on average (P = 0.005). The average number of beam-off events during whole treatment session was reduced from 457 ± 154 times to 195 ± 90 times by using the VG-PC gating system (P < 0.001). CONCLUSIONS: The developed system could improve treatment efficiency when performing respiratory-gated MR-IGRT. The VG-PC gating system could be applied to any kind of bore-type radiotherapy machine.
PURPOSE: The aim of this study is to develop a visual guidance patient-controlled (VG-PC) respiratory gating system for respiratory-gated magnetic-resonance image-guided radiation therapy (MR-IGRT) and to evaluate the performance of the developed system. METHODS: The near-real-time cine planar MR image of a patient acquired during treatment was transmitted to a beam projector in the treatment room through an optical fiber cable. The beam projector projected the cine MR images inside the bore of the ViewRay system in order to be visible to a patient during treatment. With this visual information, patients voluntarily controlled their respiration to put the target volume into the gating boundary (gating window). The effect of the presence of the beam projector in the treatment room on the image quality of the MRI was investigated by evaluating the signal-to-noise ratio (SNR), uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity with the VG-PC gating system. To evaluate the performance of the developed system, we applied the VG-PC gating system to a total of seven patients; six patients received stereotactic ablative radiotherapy (SABR) and one patient received conventional fractionated radiation therapy. RESULTS: The projected cine MR images were visible even when the room light was on. No image data loss or additional time delay during delivery of image data were observed. Every indicator representing MRI quality, including SNR, uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity exhibited values higher than the tolerance levels of the manufacturer with the VG-PC gating system; therefore, the presence of the VG-PC gating system in the treatment room did not degrade the MR image quality. The average beam-off times due to respiratory gating with and without the VG-PC gating system were 830.3 ± 278.2 s and 1264.2 ± 302.1 s respectively (P = 0.005). Consequently, the total treatment times excluding the time for patient setup with and without the VG-PC gating system were 1453.3 ± 297.3 s and 1887.2 ± 469.6 s, respectively, on average (P = 0.005). The average number of beam-off events during whole treatment session was reduced from 457 ± 154 times to 195 ± 90 times by using the VG-PC gating system (P < 0.001). CONCLUSIONS: The developed system could improve treatment efficiency when performing respiratory-gated MR-IGRT. The VG-PC gating system could be applied to any kind of bore-type radiotherapy machine.
Authors: Hyung Jin Choun; Jung-In Kim; Chang Heon Choi; Seongmoon Jung; Hyeongmin Jin; Hong-Gyun Wu; Eui Kyu Chie; Jong Min Park Journal: Phys Eng Sci Med Date: 2022-06-20
Authors: Sebastian Klüter; Sonja Katayama; C Katharina Spindeldreier; Stefan A Koerber; Gerald Major; Markus Alber; Sati Akbaba; Jürgen Debus; Juliane Hörner-Rieber Journal: Strahlenther Onkol Date: 2020-01-30 Impact factor: 3.621
Authors: Taeho Kim; Benjamin C Lewis; Alex Price; Thomas Mazur; H Michael Gach; Justin C Park; Bin Cai; Erin Wittland; Lauren Henke; Hyun Kim; Sasa Mutic; Olga Green Journal: J Appl Clin Med Phys Date: 2020-09-15 Impact factor: 2.102