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Tanaka Y, Hashimoto M, Ishigami M, Nakano M, Hasegawa T. Development of a novel delivery quality assurance system based on simultaneous verification of dose distribution and binary multi-leaf collimator opening in helical tomotherapy. Radiat Oncol 2023; 18:180. [PMID: 37919745 PMCID: PMC10621123 DOI: 10.1186/s13014-023-02366-6] [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: 03/24/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023] Open
Abstract
BACKGROUND Intensity-modulated radiation therapy (IMRT) requires delivery quality assurance (DQA) to ensure treatment accuracy and safety. Irradiation techniques such as helical tomotherapy (HT) have become increasingly complex, rendering conventional verification methods insufficient. This study aims to develop a novel DQA system to simultaneously verify dose distribution and multi-leaf collimator (MLC) opening during HT. METHODS We developed a prototype detector consisting of a cylindrical plastic scintillator (PS) and a cooled charge-coupled device (CCD) camera. Scintillation light was recorded using a CCD camera. A TomoHDA (Accuray Inc.) was used as the irradiation device. The characteristics of the developed system were evaluated based on the light intensity. The IMRT plan was irradiated onto the PS to record a moving image of the scintillation light. MLC opening and light distribution were obtained from the recorded images. To detect MLC opening, we placed a region of interest (ROI) on the image, corresponding to the leaf position, and analyzed the temporal change in the light intensity within each ROI. Corrections were made for light changes due to differences in the PS shape and irradiation position. The corrected light intensity was converted into the leaf opening time (LOT), and an MLC sinogram was constructed. The reconstructed MLC sinogram was compared with that calculated using the treatment planning system (TPS). Light distribution was obtained by integrating all frames obtained during IMRT irradiation. The light distribution was compared with the dose distribution calculated using the TPS. RESULTS The LOT and the light intensity followed a linear relationship. Owing to MLC movements, the sensitivity and specificity of the reconstructed sinogram exceeded 97%, with an LOT error of - 3.9 ± 7.8%. The light distribution pattern closely resembled that of the dose distribution. The average dose difference and the pass rate of gamma analysis with 3%/3 mm were 1.4 ± 0.2% and 99%, respectively. CONCLUSION We developed a DQA system for simultaneous and accurate verification of both dose distribution and MLC opening during HT.
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Affiliation(s)
- Yuichi Tanaka
- Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara-shi, Kanagawa, Japan.
| | - Masatoshi Hashimoto
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara-shi, Kanagawa, Japan
| | - Minoru Ishigami
- Department of Radiology, Kitasato University Hospital, 1-15-1 Kitazato, Minami-ku, Sagamihara-shi, Kanagawa, Japan
| | - Masahiro Nakano
- Department of Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-ku, Sagamihara-shi, Kanagawa, Japan
| | - Tomoyuki Hasegawa
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara-shi, Kanagawa, Japan
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Liang J, Yu F, Zhu J, Song T. [Impact of multi-leaf collimator positioning accuracy on quality control of volumetric modulation arc therapy plan for cervical cancer treated with Elekta linear accelerator]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2022; 42:1089-1094. [PMID: 35869775 DOI: 10.12122/j.issn.1673-4254.2022.07.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the influence of positioning accuracy of the multi-leaf collimators (MLC) on the passing rate of the plan dose verification for volumetric modulation arc therapy (VMAT) of cervical cancer using an Elekta linear accelerator. METHODS The dose distributions were measured using Sun Nuclear's Mapcheck and Arccheck semiconductors matrix before and after MLC calibration in30 cervical cancer patients undergoing VMAT. Dosimetric comparisons were performed with 2D and 3D gamma passing rates of 3%, 3 mm and 2%, and 2 mm. The 3D gamma distribution was reconstructed with respect to the patient's anatomy using 3DVH software to evaluate the possible influence of MLC positioning accuracy. RESULTS Before and after MLC calibration, the gamma passing rates of Mapcheck were (88.80±1.81)% and (99.25 ± 0.53)% under 3% and 3 mm standard, respectively, with an average increase of 10.45%. The corresponding gamma passing rates of Arccheck were (87.61±1.98)% and (98.13±0.99)%, respectively, with an average increase of 10.52%. The gamma passing rates of 3DVH were (89.87±2.28)% and (98.3±1.15)%, respectively, with an average increase of 8.43%. CONCLUSION The MLC positioning accuracy is one of the main factors influencing dosimetric accuracy of VMAT for cervical cancer. The application of Autocal software facilitates MLC calibration and improves the accuracy and safety of VMAT delivery for cervical cancer.
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Affiliation(s)
- J Liang
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China.,State Key Laboratory of Oncology in South China//Department of Radiotherapy, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - F Yu
- State Key Laboratory of Oncology in South China//Department of Radiotherapy, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - J Zhu
- State Key Laboratory of Oncology in South China//Department of Radiotherapy, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - T Song
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
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Kim JH, Kim B, Shin W, Son J, Choi CH, Park JM, Hwang U, Kim J, Jung S. 3D star shot analysis using MAGAT gel dosimeter for integrated imaging and radiation isocenter verification of MR-Linac system. J Appl Clin Med Phys 2022; 23:e13615. [PMID: 35436031 PMCID: PMC9195025 DOI: 10.1002/acm2.13615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 02/24/2022] [Accepted: 03/28/2022] [Indexed: 01/08/2023] Open
Abstract
Purpose This study aims to investigate a star shot analysis using a three‐dimensional (3D) gel dosimeter for the imaging and radiation isocenter verification of a magnetic resonance linear accelerator (MR‐Linac). Methods A mixture of methacrylic acid, gelatin, and tetrakis (hydroxymethyl) phosphonium chloride, called MAGAT gel, was fabricated. One MAGAT gel for each Linac and MR‐Linac was irradiated under six gantry angles. A 6 MV photon beam of Linac and a 6 MV flattening filter free beam of MR‐Linac were delivered to two MAGAT gels and EBT3 films. MR images were acquired by MR‐Linac with a clinical sequence (i.e., TrueFISP). The 3D star shot analysis for seven consecutive slices of the MR images with TrueFISP was performed. The 2D star shot analysis for the central plane of the gel was compared to the results from the EBT3 films. The radius of isocircle (ICr) and the distance between the center of the circle and the center marked on the image (ICd) were evaluated. Results For MR‐Linac with MAGAT gel measurements, ICd at the central plane was 0.46 mm for TrueFISP. Compared to EBT3 film measurements, the differences in ICd and ICr for both Linac and MR‐Linac were within 0.11 and 0.13 mm, respectively. For the 3D analysis, seven consecutive slices of TrueFISP images were analyzed and the maximum radii of isocircles (ICr_max) were 0.18 mm for Linac and 0.73 mm for MR‐Linac. The tilting angles of radiation axis were 0.31° for Linac and 0.10° for MR‐Linac. Conclusion The accuracy of 3D star shot analysis using MAGAT gel was comparable to that of EBT3 film, having a capability for integrated analysis for imaging isocenter and radiation isocenter. 3D star shot analysis using MAGAT gel can provide 3D information of radiation isocenter, suggesting a quantitative extent of gantry‐tilting.
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Affiliation(s)
- Jeong Ho Kim
- Department of Radiation OncologySamsung Changwon HospitalSungkyunkwan University School of MedicineChangwonRepublic of Korea
| | - Bitbyeol Kim
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
| | - Wook‐Geun Shin
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
| | - Jaeman Son
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
- Institute of Radiation MedicineSeoul National University Medical Research CenterSeoulRepublic of Korea
- Biomedical Research InstituteSeoul National University HospitalSeoulRepublic of Korea
| | - Chang Heon Choi
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
- Institute of Radiation MedicineSeoul National University Medical Research CenterSeoulRepublic of Korea
- Biomedical Research InstituteSeoul National University HospitalSeoulRepublic of Korea
| | - Jong Min Park
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
- Institute of Radiation MedicineSeoul National University Medical Research CenterSeoulRepublic of Korea
- Biomedical Research InstituteSeoul National University HospitalSeoulRepublic of Korea
- Department of Radiation OncologySeoul National University College of MedicineSeoulRepublic of Korea
- Robotics Research Laboratory for Extreme EnvironmentsAdvanced Institute of Convergence TechnologySuwonRepublic of Korea
| | - Ui‐Jung Hwang
- Department of Radiation OncologyChungnam National University Sejong HospitalSejongRepublic of Korea
| | - Jung‐in Kim
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
- Institute of Radiation MedicineSeoul National University Medical Research CenterSeoulRepublic of Korea
- Biomedical Research InstituteSeoul National University HospitalSeoulRepublic of Korea
| | - Seongmoon Jung
- Department of Radiation OncologySeoul National University HospitalSeoulRepublic of Korea
- Institute of Radiation MedicineSeoul National University Medical Research CenterSeoulRepublic of Korea
- Biomedical Research InstituteSeoul National University HospitalSeoulRepublic of Korea
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Tsuneda M, Nishio T, Ezura T, Karasawa K. Plastic scintillation dosimeter with a conical mirror for measuring 3D dose distribution. Med Phys 2021; 48:5639-5650. [PMID: 34389992 DOI: 10.1002/mp.15164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 03/22/2021] [Accepted: 08/01/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To test the measurement technique of the three-dimensional (3D) dose distribution measured image by capturing the scintillation light generated using a plastic scintillator and a scintillating screen. METHODS Our imaging system constituted a column shaped plastic scintillator covered by a Gd2 O2 S:Tb scintillating screen, a conical mirror and a cooled CCD camera. The scintillator was irradiated with 6 MV photon beams. Meanwhile, the irradiated plan was prepared for the static field plans, two-field plan (2F plan) and the conformal arc plan (CA plan). The 2F plan contained 16 mm2 and 10 mm2 fields irradiated from gantry angles of 0° and 25°, respectively. The gantry was rotated counterclockwise from 45° to 315° for the CA plan. The field size was then obtained as 10 mm2 . A Monte Carlo simulation was performed in the experimental geometry to obtain the calculated 3D dose distribution as the reference data. Dose response was acquired by comparing between the reference and the measurement. The dose rate dependence was verified by irradiating the same MU value at different dose rates ranging from 100 to 600 MU/min. Deconvolution processing was applied to the measured images for the correction of light blurring. The measured 3D dose distribution was reconstructed from each measured image. Gamma analysis was performed to these 3D dose distributions. The gamma criteria were 3% for the dose difference, 2 mm for the distance-to-agreement and 10% for the threshold. RESULTS Dose response for the scintillation light was linear. The variation in the light intensity for the dose rate ranging from 100 to 600 MU/min was less than 0.5%, while our system presents dose rate independence. For the 3D dose measurement, blurring of light through deconvolution processing worked well. The 3D gamma passing rate (3D GPR) for the 10 × 10 mm2 , 16 × 16 mm2 , and 20 × 20 mm2 fields were observed to be 99.3%, 98.8%, and 97.8%, respectively. Reproducibility of measurement was verified. The 3D GPR results for the 2F plan and the CA plan were 99.7% and 100%, respectively. CONCLUSIONS We developed a plastic scintillation dosimeter and demonstrated that our system concept can act as a suitable technique for measuring the 3D dose distribution from the gamma results. In the future, we will attempt to measure the 4D dose distribution for clinical volumetric modulated arc radiation therapy (VMAT)-SBRTplans.
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Affiliation(s)
- Masato Tsuneda
- Department of Radiation Oncology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Teiji Nishio
- Department of Medical Physics, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
| | - Takatomo Ezura
- Division of Radiation Medical Physics, Kanagawa Cancer Center, Yokohama, Kanagawa, Japan
| | - Kumiko Karasawa
- Department of Radiation Oncology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
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Rilling M, Allain G, Thibault S, Archambault L. Tomographic‐based 3D scintillation dosimetry using a three‐view plenoptic imaging system. Med Phys 2020; 47:3636-3646. [DOI: 10.1002/mp.14213] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 11/07/2022] Open
Affiliation(s)
- Madison Rilling
- Département de physique de génie physique et d’optique Faculté des sciences et de génie Université Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
- Centre d’optique photonique et laser Université Laval 2375 rue de la Terrasse Québec QC G1V 0A6 Canada
- Centre de recherche du CHU de Québec‐Université Laval Hôtel‐Dieu de Québec 11 Côte du Palais Québec QC G1R 2J6 Canada
- Centre de recherche sur le cancer de l’Université Laval 9 rue McMahon Québec QC G1R 3S3 Canada
| | - Guillaume Allain
- Département de physique de génie physique et d’optique Faculté des sciences et de génie Université Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
| | - Simon Thibault
- Département de physique de génie physique et d’optique Faculté des sciences et de génie Université Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
| | - Louis Archambault
- Département de physique de génie physique et d’optique Faculté des sciences et de génie Université Laval 1045 avenue de la Médecine Québec QC G1V 0A6 Canada
- Centre de recherche du CHU de Québec‐Université Laval Hôtel‐Dieu de Québec 11 Côte du Palais Québec QC G1R 2J6 Canada
- Centre de recherche sur le cancer de l’Université Laval 9 rue McMahon Québec QC G1R 3S3 Canada
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Velten C, Wang YF, Adamovics J, Wuu CS. 3D isocentricity analysis for clinical linear accelerators. Med Phys 2020; 47:1460-1467. [PMID: 31970794 DOI: 10.1002/mp.14039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 01/02/2020] [Accepted: 01/09/2020] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To perform a three-dimensional (3D) concurrent isocentricity measurement of a clinical linear accelerator's (linac) using a single 3D dosimeter, PRESAGE. METHODS A 3D dosimeter, PRESAGE, set up on the treatment couch of a Varian TrueBeam LINAC using the setup lasers, was irradiated under gantry angles of 0 ∘ , 50 ∘ , 160 ∘ , and 270 ∘ with the couch fixed at 0 ∘ and subsequently, under couch angles of 10 ∘ , 330 ∘ , 300 ∘ , and 265 ∘ with the gantry fixed at 270 ∘ . The 1 cm 2 (at 100 cm SAD) square fields were delivered at 6 MV with 800 MU/field. After irradiation, the dosimeter was scanned using a single-beam optical scanner and images were reconstructed with submillimeter resolution using filtered back-projection. Postprocessing was used to extract views parallel to the star-shot planes from which beam trajectories and the smallest circles enclosing these were drawn and extracted. These circles and information from the view orthogonal to both star-shots were used to represent the rotational centers as spheroids. The linac isocenter was defined by the distribution of midpoints between any, randomly selected, points lying inside the center spheroids defined by the table and gantry rotations; isocenter location and size were defined by the average midpoint and the distribution's semi-axes. Collimator rotations were not included in this study. RESULTS Relative to the setup center defined by lasers, the table and gantry rotation center coordinates (lat., long., vert.) were measured in units of millimeters, to be (-0.24, 0.18, -0.52) and (0.10, 0.53, -0.52), respectively. Displacements from the setup center were 0.60 and 0.75 mm for the table and gantry centers, while the distance between them measured 0.49 mm. The linac's radiation isocenter was calculated to be at (-0.07, -0.17, 0.51) relative to the setup lasers and its size was found to be most easily described by a spheroid prolate in vertical direction with semi-axis lengths of 0.13 and 0.23 mm for the lateral-longitudinal and vertical directions, respectively. CONCLUSIONS This study demonstrates how to measure the location and sizes of rotational centers in 3D with one setup. The proposed method provides a more comprehensive view on the isocentricity of LINAC than the conventional two-dimensional film measurements. Additionally, a new definition of isocenter and its size was proposed.
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Affiliation(s)
- Christian Velten
- Department of Radiation Oncology, Columbia University, New York, NY, USA.,Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA
| | - Yi-Fang Wang
- Department of Radiation Oncology, Columbia University, New York, NY, USA
| | - John Adamovics
- Department of Chemistry, Biochemistry, and Physics, Rider University, Lawrenceville, NJ, USA
| | - Cheng-Shie Wuu
- Department of Radiation Oncology, Columbia University, New York, NY, USA
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Tsuneda M, Nishio T, Saito A, Tanaka S, Suzuki T, Kawahara D, Matsushita K, Nishio A, Ozawa S, Karasawa K, Nagata Y. Erratum: “A novel verification method using a plastic scintillator imagining system for assessment of gantry sag in radiotherapy” [Med. Phys. 45(6), 2411-2424 (2018)]. Med Phys 2018. [DOI: 10.1002/mp.13080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Masato Tsuneda
- Department of Radiation Oncology; Graduate School of Biomedical & Health Sciences; Hiroshima University; 1-2-3 Kasumi, Minami-ku Hiroshima 734-8551 Japan
- Department of Radiation Oncology; Tokyo Women's Medical University; 8-1 Kawada-cho, Shinjuku-ku Tokyo 162-8666 Japan
| | - Teiji Nishio
- Department of Medical Physics; Graduate School of Medicine; Tokyo Women's Medical University; 8-1 Kawada-cho, Shinjuku-ku Tokyo 162-8666 Japan
| | - Akito Saito
- Department of Radiation Oncology; Hiroshima University Hospital; 1-2-3 Kasumi, Minami-ku Hiroshima 734-8551 Japan
| | - Sodai Tanaka
- Department of Nuclear Engineering and Management; School of Engineering; The University of Tokyo; 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Tatsuhiko Suzuki
- Department of Radiation Oncology; Graduate School of Biomedical & Health Sciences; Hiroshima University; 1-2-3 Kasumi, Minami-ku Hiroshima 734-8551 Japan
| | - Daisuke Kawahara
- Department of Radiation Oncology; Graduate School of Biomedical & Health Sciences; Hiroshima University; 1-2-3 Kasumi, Minami-ku Hiroshima 734-8551 Japan
| | - Keiichiro Matsushita
- Department of Radiology; Kyoto Prefecture University of Medicine; 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku Kyoto 602-8566 Japan
| | - Aya Nishio
- Department of Radiation Oncology; Tokyo Women's Medical University; 8-1 Kawada-cho, Shinjuku-ku Tokyo 162-8666 Japan
| | - Shuichi Ozawa
- Hiroshima High-Precision Radiotherapy Cancer Center; 2-2 Hutabanosato, Higashi-ku Hiroshima 732-0057 Japan
| | - Kumiko Karasawa
- Department of Radiation Oncology; Tokyo Women's Medical University; 8-1 Kawada-cho, Shinjuku-ku Tokyo 162-8666 Japan
| | - Yasushi Nagata
- Hiroshima High-Precision Radiotherapy Cancer Center; 2-2 Hutabanosato, Higashi-ku Hiroshima 732-0057 Japan
- Department of Radiation Oncology; Graduate School of Biomedical & Health Sciences; Hiroshima University; 1-2-3 Kasumi, Minami-ku Hiroshima 734-8551 Japan
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