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Nakao M, Ozawa S, Miura H, Yamada K, Hayata M, Hayashi K, Kawahara D, Nakashima T, Ochi Y, Okumura T, Kunimoto H, Kawakubo A, Kusaba H, Nozaki H, Habara K, Tohyama N, Nishio T, Nakamura M, Minemura T, Okamoto H, Ishikawa M, Kurooka M, Shimizu H, Hotta K, Saito M, Nakano M, Tsuneda M, Nagata Y. CT number calibration audit in photon radiation therapy. Med Phys 2024; 51:1571-1582. [PMID: 38112216 DOI: 10.1002/mp.16887] [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: 01/03/2023] [Revised: 06/29/2023] [Accepted: 11/26/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Inadequate computed tomography (CT) number calibration curves affect dose calculation accuracy. Although CT number calibration curves registered in treatment planning systems (TPSs) should be consistent with human tissues, it is unclear whether adequate CT number calibration is performed because CT number calibration curves have not been assessed for various types of CT number calibration phantoms and TPSs. PURPOSE The purpose of this study was to investigate CT number calibration curves for mass density (ρ) and relative electron density (ρe ). METHODS A CT number calibration audit phantom was sent to 24 Japanese photon therapy institutes from the evaluating institute and scanned using their individual clinical CT scan protocols. The CT images of the audit phantom and institute-specific CT number calibration curves were submitted to the evaluating institute for analyzing the calibration curves registered in the TPSs at the participating institutes. The institute-specific CT number calibration curves were created using commercial phantom (Gammex, Gammex Inc., Middleton, WI, USA) or CIRS phantom (Computerized Imaging Reference Systems, Inc., Norfolk, VA, USA)). At the evaluating institute, theoretical CT number calibration curves were created using a stoichiometric CT number calibration method based on the CT image, and the institute-specific CT number calibration curves were compared with the theoretical calibration curve. Differences in ρ and ρe over the multiple points on the curve (Δρm and Δρe,m , respectively) were calculated for each CT number, categorized for each phantom vendor and TPS, and evaluated for three tissue types: lung, soft tissues, and bones. In particular, the CT-ρ calibration curves for Tomotherapy TPSs (ACCURAY, Sunnyvale, CA, USA) were categorized separately from the Gammex CT-ρ calibration curves because the available tissue-equivalent materials (TEMs) were limited by the manufacturer recommendations. In addition, the differences in ρ and ρe for the specific TEMs (ΔρTEM and Δρe,TEM , respectively) were calculated by subtracting the ρ or ρe of the TEMs from the theoretical CT-ρ or CT-ρe calibration curve. RESULTS The mean ± standard deviation (SD) of Δρm and Δρe,m for the Gammex phantom were -1.1 ± 1.2 g/cm3 and -0.2 ± 1.1, -0.3 ± 0.9 g/cm3 and 0.8 ± 1.3, and -0.9 ± 1.3 g/cm3 and 1.0 ± 1.5 for lung, soft tissues, and bones, respectively. The mean ± SD of Δρm and Δρe,m for the CIRS phantom were 0.3 ± 0.8 g/cm3 and 0.9 ± 0.9, 0.6 ± 0.6 g/cm3 and 1.4 ± 0.8, and 0.2 ± 0.5 g/cm3 and 1.6 ± 0.5 for lung, soft tissues, and bones, respectively. The mean ± SD of Δρm for Tomotherapy TPSs was 2.1 ± 1.4 g/cm3 for soft tissues, which is larger than those for other TPSs. The mean ± SD of Δρe,TEM for the Gammex brain phantom (BRN-SR2) was -1.8 ± 0.4, implying that the tissue equivalency of the BRN-SR2 plug was slightly inferior to that of other plugs. CONCLUSIONS Latent deviations between human tissues and TEMs were found by comparing the CT number calibration curves of the various institutes.
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Affiliation(s)
- Minoru Nakao
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Shuichi Ozawa
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Hideharu Miura
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Kiyoshi Yamada
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Masahiro Hayata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Kosuke Hayashi
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Daisuke Kawahara
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
| | - Takeo Nakashima
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Yusuke Ochi
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Takuro Okumura
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Haruhide Kunimoto
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima Prefectural Hospital, Hiroshima, Japan
| | - Atsushi Kawakubo
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Hayate Kusaba
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Radiation Therapy Department, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan
| | - Hiroshige Nozaki
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Division of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Kosaku Habara
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Division of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Naoki Tohyama
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Division of Medical Physics, Tokyo Bay Makuhari Clinic for Advanced Imaging, Cancer Screening, and High-Precision Radiotherapy, Chiba, Japan
| | - Teiji Nishio
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Medical Physics Laboratory, Division of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mitsuhiro Nakamura
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto, Japan
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Toshiyuki Minemura
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Division of Medical Support and Partnership, Institute for Cancer Control, National Cancer Center, Tokyo, Japan
| | - Hiroyuki Okamoto
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Tokyo, Japan
| | - Masayori Ishikawa
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Faculty of Health Sciences, Hokkaido University, Hokkaido, Japan
| | - Masahiko Kurooka
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Therapy, Tokyo Medical University Hospital, Tokyo, Japan
| | - Hidetoshi Shimizu
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Aichi, Japan
| | - Kenji Hotta
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Chiba, Japan
- Particle Therapy Division, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Masahide Saito
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiology, University of Yamanashi, Yamanashi, Japan
| | - Masahiro Nakano
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Department of Radiation Oncology, Kitasato University School of Medicine, Kanagawa, Japan
| | - Masato Tsuneda
- Medical Physics Working Group in Japan Clinical Oncology Group - Radiation Therapy Study Group, Tokyo, Japan
- Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasushi Nagata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
- Technical Support Working Group in Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
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Tsuneda M, Abe K, Fujita Y, Ikeda Y, Furuyama Y, Uno T. Elekta Unity MR-linac commissioning: mechanical and dosimetry tests. JOURNAL OF RADIATION RESEARCH 2022; 64:73-84. [PMCID: PMC9855313 DOI: 10.1093/jrr/rrac072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/16/2022] [Indexed: 06/26/2023]
Abstract
We report the commissioning results of Elekta Unity for the dosimetric performance and mechanical quality assurance (QA), and propose additional commissioning procedures. Mechanical tests included multi-leaf collimator (MLC) positional accuracy, radiation isocenter diameter at the center and off-center position, and coincidence between the magnetic resonance (MR) image center and radiation isocenter. Comparisons between the measurements and calculations of the simple irradiated field, intensity modulated radiation therapy (IMRT) commissioning, MLC output factor ratio, validation of independent dose calculation software and end-to-end testing were performed to evaluate dosimetric performance. The average values of the MLC positional accuracy for film- and imaging device-based analysis were −0.1 and 0.3 mm, respectively. The measured radiation isocenter size was 0.41 mm, and the off-center results were within 1 mm. The coincidence was −0.21, −1.19 and 0.49 mm along the x-, y- and z-axes, respectively. The calculated percent depth doses (PDD) and profiles agreed with the measurements. The results of independent dose calculation were within the action level recommended by American Associations of Physicist in Medicine. The gamma passing rate (GPR) for IMRT commissioning was 98.6 ± 0.9%, and end-to-end testing of adapted plans showed agreement within 2% between the measurement and calculation. We reported the results of mechanical and dosimetric performances of Elekta Unity, and proposed novel commissioning procedures. Our results should provide knowledge to the physics community for enhancing the QA programs.
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Affiliation(s)
- Masato Tsuneda
- Corresponding author. Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University. 1-8-1 Inohana, Chuo-ku, Chiba, 260-8677 Japan. E-mail: , , Tel: +81-43-226-2100, Fax: +81-43-226-2101
| | - Kota Abe
- Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University, Chiba, 260-8677 Japan
| | - Yukio Fujita
- Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University, Chiba, 260-8677 Japan
- Department of Radiation Sciences, Komazawa University, Setagaya, Tokyo, 259-1193 Japan
| | - Yohei Ikeda
- Department of Radiology, Chiba University Hospital, Chiba, 260-8670 Japan
| | - Yoshinobu Furuyama
- Department of Radiology, Chiba University Hospital, Chiba, 260-8670 Japan
| | - Takashi Uno
- Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, 260-8677 Japan
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Nishio T, Nakamura M, Okamoto H, Kito S, Minemura T, Ozawa S, Kumazaki Y, Ishikawa M, Tohyama N, Kurooka M, Nakashima T, Shimizu H, Suzuki R, Ishikura S, Nishimura Y. An overview of the medical-physics-related verification system for radiotherapy multicenter clinical trials by the Medical Physics Working Group in the Japan Clinical Oncology Group-Radiation Therapy Study Group. JOURNAL OF RADIATION RESEARCH 2020; 61:999-1008. [PMID: 32989445 PMCID: PMC7674673 DOI: 10.1093/jrr/rraa089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/25/2020] [Indexed: 05/14/2023]
Abstract
The Japan Clinical Oncology Group-Radiation Therapy Study Group (JCOG-RTSG) has initiated several multicenter clinical trials for high-precision radiotherapy, which are presently ongoing. When conducting multi-center clinical trials, a large difference in physical quantities, such as the absolute doses to the target and the organ at risk, as well as the irradiation localization accuracy, affects the treatment outcome. Therefore, the differences in the various physical quantities used in different institutions must be within an acceptable range for conducting multicenter clinical trials, and this must be verified with medical physics consideration. In 2011, Japan's first Medical Physics Working Group (MPWG) in the JCOG-RTSG was established to perform this medical-physics-related verification for multicenter clinical trials. We have developed an auditing method to verify the accuracy of the absolute dose and the irradiation localization. Subsequently, we credentialed the participating institutions in the JCOG multicenter clinical trials that were using stereotactic body radiotherapy (SBRT) for lungs, intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for several disease sites, and proton beam therapy (PT) for the liver. From the verification results, accuracies of the absolute dose and the irradiation localization among the participating institutions of the multicenter clinical trial were assured, and the JCOG clinical trials could be initiated.
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Affiliation(s)
- Teiji Nishio
- Corresponding author. Department of Medical Physics, Graduate School of Medicine, Tokyo Women’s Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. Tel: +81-3-3353-8111; Fax: +81-3-5269-7040;
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human He Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Satoshi Kito
- Department of Radiology, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Kotobashi, Sumida-ku, Tokyo 130-8575, Japan
- Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human He Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Toshiyuki Minemura
- Division of Medical Support and Partnership, Center for Cancer Control and Information Services, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Shuichi Ozawa
- Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
- Hiroshima High-Precision Radiotherapy Cancer Center, 3-2-2, Futabanosato, Higashi-ku, Hiroshima 732-0057, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Masayori Ishikawa
- Faculty of Health Sciences, Hokkaido University, N-12 W-5 Kita-ku, Sapporo, 060-0812, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, 1-17 Toyosuna, Mihama-ku, Chiba, 261-0024, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, 6-7-1, Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Takeo Nakashima
- Radiation Therapy Section, Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi 464-8681, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Ryusuke Suzuki
- Department of Medical Physics, Hokkaido University Hospital, North-14, West-5, Kita-Ku, Sapporo, Hokkaido 060-8638, Japan
- Medical Physics Working Group (MPWG) in Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Satoshi Ishikura
- Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
- Radiotherapy Committee (RC) in Japan Clinical Oncology Group, Tokyo, Japan
- Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan
- Japan Clinical Oncology Group - Radiation Therapy Study Group (JCOG-RTSG), Tokyo, Japan
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Nakao M, Ozawa S, Miura H, Yamada K, Habara K, Hayata M, Kusaba H, Kawahara D, Miki K, Nakashima T, Ochi Y, Tsuda S, Seido M, Morimoto Y, Kawakubo A, Nozaki H, Nagata Y. Development of a CT number calibration audit phantom in photon radiation therapy: A pilot study. Med Phys 2020; 47:1509-1522. [PMID: 32026482 PMCID: PMC7216906 DOI: 10.1002/mp.14077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 01/24/2023] Open
Abstract
PURPOSE In photon radiation therapy, computed tomography (CT) numbers are converted into values for mass density (MD) or relative electron density to water (RED). CT-MD or CT-RED calibration tables are relevant for human body dose calculation in an inhomogeneous medium. CT-MD or CT-RED calibration tables are influenced by patient imaging (CT scanner manufacturer, scanning parameters, and patient size), the calibration process (tissue-equivalent phantom manufacturer, and selection of tissue-equivalent material), differences between tissue-equivalent materials and standard tissues, and the dose calculation algorithm applied; however, a CT number calibration audit has not been established. The purposes of this study were to develop a postal audit phantom, and to establish a CT number calibration audit process. METHODS A conventional stoichiometric calibration conducts a least square fit of the relationships between the MD, material weight, and measured CT number, using two parameters. In this study, a new stoichiometric CT number calibration scheme has been empirically established, using three parameters to harmonize the calculated CT number with the measured CT number for air and lung tissue. In addition, the suitable material set and the minimal number of materials required for stoichiometric CT number calibration were determined. The MDs and elemental weights from the International Commission on Radiological Protection Publication 110 were used as standard tissue data, to generate the CT-MD and CT-RED calibration tables. A small-sized, CT number calibration phantom was developed for a postal audit, and stoichiometric CT number calibration with the phantom was compared to the CT number calibration tables registered in the radiotherapy treatment planning systems (RTPSs) associated with five radiotherapy institutions. RESULTS When a least square fit was performed for the stoichiometric CT number calibration with the three parameters, the calculated CT number showed better agreement with the measured CT number. We established stoichiometric CT number calibration using only two materials because the accuracy of the process was determined not by the number of used materials but by the number of elements contained. The stoichiometric CT number calibration was comparable to the tissue-substitute calibration, with a dose difference less than 1%. An outline of the CT number calibration audit was demonstrated through a multi-institutional study. CONCLUSIONS We established a new stoichiometric CT number calibration method for validating the CT number calibration tables registered in RTPSs. We also developed a CT number calibration phantom for a postal audit, which was verified by the performances of multiple CT scanners located at several institutions. The new stoichiometric CT number calibration has the advantages of being performed using only two materials, and decreasing the difference between the calculated and measured CT numbers for air and lung tissue. In the future, a postal CT number calibration audit might be achievable using a smaller phantom.
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Affiliation(s)
- Minoru Nakao
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
- Department of Radiation OncologyGraduate School of Biomedical & Health SciencesHiroshima University1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Shuichi Ozawa
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
- Department of Radiation OncologyGraduate School of Biomedical & Health SciencesHiroshima University1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Hideharu Miura
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
- Department of Radiation OncologyGraduate School of Biomedical & Health SciencesHiroshima University1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Kiyoshi Yamada
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
| | - Kosaku Habara
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
| | - Masahiro Hayata
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
| | - Hayate Kusaba
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
| | - Daisuke Kawahara
- Department of Radiation OncologyGraduate School of Biomedical & Health SciencesHiroshima University1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Kentaro Miki
- Department of Radiation OncologyHiroshima University Hospital1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Takeo Nakashima
- Radiation Therapy SectionDepartment of Clinical SupportHiroshima University Hospital1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Yusuke Ochi
- Radiation Therapy SectionDepartment of Clinical SupportHiroshima University Hospital1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Shintaro Tsuda
- Radiation Therapy SectionDepartment of Clinical SupportHiroshima University Hospital1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
| | - Mineaki Seido
- Department of RadiologyHiroshima Prefectural Hospital1‐5‐54, Ujinakanda, Minami‐kuHiroshima734‐8530Japan
| | - Yoshiharu Morimoto
- Department of RadiologyHiroshima Prefectural Hospital1‐5‐54, Ujinakanda, Minami‐kuHiroshima734‐8530Japan
| | - Atsushi Kawakubo
- Radiation Therapy DepartmentHiroshima City Hiroshima Citizens Hospital7‐33, Motomachi, Naka‐kuHiroshima730‐8518Japan
| | - Hiroshige Nozaki
- Division of RadiologyHiroshima Red Cross Hospital & Atomic‐bomb Survivors Hospital1‐9‐6, Senda, Naka‐kuHiroshima730‐8619Japan
| | - Yasushi Nagata
- Hiroshima High‐Precision Radiotherapy Cancer Center3‐2‐2, Futabanosato, Higashi‐kuHiroshima732‐0057Japan
- Department of Radiation OncologyGraduate School of Biomedical & Health SciencesHiroshima University1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
- Department of Radiation OncologyHiroshima University Hospital1‐2‐3 Kasumi, Minami‐kuHiroshima734‐8551Japan
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Nishio T, Tachibana H, Kase Y, Hotta K, Nakamura M, Tamura M, Terunuma T, Toshito T, Yamashita H, Ishikura S, Fuji H, Akimoto T, Nishimura Y. Liver phantom design and dosimetric verification in participating institutions for a proton beam therapy in patients with resectable hepatocellular carcinoma: Japan Clinical Oncology Group trial (JCOG1315C). Radiother Oncol 2019; 140:98-104. [PMID: 31265942 DOI: 10.1016/j.radonc.2019.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 05/15/2019] [Accepted: 06/05/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND PURPOSE In Japan, the first domestic clinical trial of proton beam therapy for the liver was initiated as the Japan Clinical Oncology Group trial (JCOG1315C: Non-randomized controlled study comparing proton beam therapy and hepatectomy for resectable hepatocellular carcinoma). Purposes of this study were to develop a new dosimetric verification system and to carry out a credentialing for the JCOG1315C clinical trial. MATERIALS AND METHODS Accuracy and differences in doses in proton treatment planning among participating institutions were surveyed and investigated. We designed and developed a suitable water tank-type liver phantom for a dosimetric verification of proton beam therapy for liver. In a visiting survey of five institutions participating in the clinical trial, we performed the dosimetric verification using the liver phantom and an air-filled ionization chamber. RESULTS The shape of the dose distributions calculated in proton treatment planning was characteristic and dependent on the manufacturers of the proton beam therapy system, the proton treatment planning system and the setup at the participating institutions. Widths of the lateral penumbra were 5.8-12.7 mm among participating institutions. The accuracy between the calculated and the measured doses in the proton irradiation was within 3% at five measurement points including both points on the isocenter and off the isocenter. CONCLUSIONS These findings confirmed the accuracy of the delivery doses in the institutions participating in the clinical trial, and the clinical trial with integration of all institutions (five institutions) could be initiated.
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Affiliation(s)
- Teiji Nishio
- Department of Medical Physics, Graduate School of Medicine, Tokyo Women's Medical University, Japan.
| | - Hidenobu Tachibana
- Division of Radiation Oncology and Particle Therapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Kashiwa, Japan
| | - Yuki Kase
- Proton Therapy Division, Shizuoka Cancer Center Research Institute, Japan
| | - Kenji Hotta
- Division of Radiation Oncology and Particle Therapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Kashiwa, Japan
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan
| | - Masaya Tamura
- Department of Medical Physics, Hokkaido University Hospital, Sapporo, Japan
| | | | - Toshiyuki Toshito
- Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Japan
| | - Haruo Yamashita
- Proton Therapy Division, Shizuoka Cancer Center Research Institute, Japan
| | - Satoshi Ishikura
- Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, Japan
| | - Hiroshi Fuji
- Department of Radiation Oncology, National Center for Child Health and Development, Tokyo, Japan
| | - Tetsuo Akimoto
- Division of Radiation Oncology and Particle Therapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Kashiwa, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
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Lambrecht ML, Eaton DJ, Sonke JJ, Nestle U, Peulen H, Weber DC, Verheij M, Hurkmans CW. Results of a multicentre dosimetry audit using a respiratory phantom within the EORTC LungTech trial. Radiother Oncol 2019; 138:106-113. [PMID: 31252291 DOI: 10.1016/j.radonc.2019.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The EORTC 22113-08113 LungTech trial assesses the safety and efficacy of SBRT for centrally located NSCLC. To insure protocol compliance an extensive RTQA procedure was implemented. METHODS Twelve centres were audited using a CIRS008A phantom. The phantom was scanned using target inserts of 7.5 mm and 12.5 mm radius in static condition. For the 7.5 mm insert a 4DCT was acquired while moving according to a cos6 function. Treatment plans were measured using film and an ionization chamber. Wilcoxon's signed-rank tests were performed to compare the three plans across institutions. A Spearman correlation was calculated to evaluate the influence of factors such as PTV, slice thickness and total number of monitor units on the dosimetric results. RESULTS The reference output dose median [min, max] variation was 0.5% [-1.1, +1.5]. The median deviations between chamber doses and point-planned doses were 1.8% [-0.1; 6.7] for the 7.5 mm and 1.1% [-2.8; 5.0] for the 12.5 mm sphere in static situation and 3.2% [-3.2; 15.7] for the dynamic situation. Film gamma median pass rates were 92.0% [68.0, 99.0] for 7.5 mm static, 96.2% [73.0, 99.0] for 12.5 mm static and 71.0% [40.0, 99.0] for 7.5 mm dynamic. Wilcoxon's signed-rank tests showed that the dynamic irradiations resulted in significantly lower gamma pass rates compared to the 12.5 mm static plan (p = 0.001). The total number of MUs per plan was correlated to both film and IC results. CONCLUSION An end-to-end audit was successfully performed, revealing important variations between institutions especially in dynamic irradiations. This shows the importance of dosimetry audits and the potentials for further technique and methodology improvements.
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Affiliation(s)
- Marie Lara Lambrecht
- Department of Radiation Oncology, Catharina Hospital, Eindhoven, The Netherlands
| | - David J Eaton
- Radiotherapy Trials QA Group, Mount Vernon Hospital, Northwood, United Kingdom
| | - Jan-Jakob Sonke
- Department of Radiation Oncology, The Netherland Cancer Institute, Amsterdam, The Netherlands
| | - Ursula Nestle
- Department of Radiation Oncology, KlinikenMaria Hilf, Mönchengladbach, Germany
| | - Heike Peulen
- Department of Radiation Oncology, Catharina Hospital, Eindhoven, The Netherlands
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Villigen, Switzerland
| | - Marcel Verheij
- Department of Radiation Oncology, The Netherland Cancer Institute, Amsterdam, The Netherlands
| | - Coen W Hurkmans
- Department of Radiation Oncology, Catharina Hospital, Eindhoven, The Netherlands.
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Kumazaki Y, Ozawa S, Nakamura M, Kito S, Minemura T, Tachibana H, Nishio T, Ishikura S, Nishimura Y. An end-to-end postal audit test to examine the coincidence between the imaging isocenter and treatment beam isocenter of the IGRT linac system for Japan Clinical Oncology Group (JCOG) clinical trials. Phys Med 2018; 53:145-152. [PMID: 30241749 DOI: 10.1016/j.ejmp.2018.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/06/2018] [Accepted: 08/12/2018] [Indexed: 10/28/2022] Open
Abstract
PURPOSE The aim of this study was to develop an end-to-end postal audit test to examine the coincidence between the imaging isocenter and treatment beam isocenter of the image guided radiotherapy (IGRT) linac system for Japan Clinical Oncology Group (JCOG) trials, as a part of IGRT credentialing of institutions participating in JCOG trials. METHODS We developed an end-to-end postal audit test to verify radiation positional errors associated with IGRT techniques. This test is intended for simulating a clinical IGRT flow and uses a static cubic phantom measuring 15 × 15 × 15 cm3 and weighing approximately 3.4 kg. The phantom has four gold fiducial markers and a spherical dummy target for setup, with known shift values from the phantom center. Two pairs of Gafchromic RTQA2 films were inserted 5 mm from the phantom's anterior-posterior and right-left surfaces. Radiation positional errors at the isocenter were determined by analyzing the center of the radiation field on the films and the known shift values of the dummy target. The test was performed on 47 IGRT devices at 35 institutions. RESULTS Radiation positional errors were within acceptance levels (1 mm/1°) for 42 IGRT devices (89.4%) in the first check. Median time to complete IGRT credentialing was 11.5 days. This audit method was applicable for any radiotherapy machine with an IGRT device. CONCLUSIONS A postal audit test to verify radiation positional errors for JCOG trials was successfully developed. In the postal audit, all but one institution passed this credentialing item within two trials.
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Affiliation(s)
- Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan.
| | - Shuichi Ozawa
- Department of Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Mitsuhiro Nakamura
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Satoshi Kito
- Radiation Physics Section, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-Ku, Tokyo 113-8677, Japan
| | - Toshiyuki Minemura
- Center for Cancer Control and Information Services, National Cancer Center, 5-1-1 Tsukiji, Chuo-Ku, Tokyo 104-0045, Japan
| | - Hidenobu Tachibana
- Particle Therapy Division, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa City, Chiba 277-8577, Japan
| | - Teiji Nishio
- Department of Medical Physics, Tokyo Women's Medical University, 8-1 Kawatamachi, Shinjuku, Tokyo 162-8666, Japan
| | - Satoshi Ishikura
- Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan
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Inoue T, Katoh N, Ito YM, Kimura T, Nagata Y, Kuriyama K, Onishi H, Yoshitake T, Shioyama Y, Iizuka Y, Inaba K, Konishi K, Kokubo M, Karasawa K, Kozuka T, Tanaka K, Sakakibara-Konishi J, Kinoshita I, Shirato H. Stereotactic body radiotherapy to treat small lung lesions clinically diagnosed as primary lung cancer by radiological examination: A prospective observational study. Lung Cancer 2018; 122:107-112. [PMID: 30032817 DOI: 10.1016/j.lungcan.2018.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Even with advanced image guidance, biopsies occasionally fail to diagnose small lung lesions, which are highly suggestive of primary lung cancer by radiological examination. The aim of this study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) to treat small lung lesions clinically diagnosed as primary lung cancer. MATERIALS AND METHODS This is a prospective, multi-institutional observation study. Strict inclusion and exclusion criteria were determined in a nation-wide consensus meeting and used to include patients who were clinically diagnosed with primary lung cancer using precise imaging modalities, for whom further surgical intervention was not feasible, who refused watchful waiting, and who were highly tolerable of SBRT with informed consent. SBRT was performed with 48 Gy in 4 fractions at the tumor isocenter. RESULTS From August 2009 to August 2014, 62 patients from 11 institutions were enrolled. Their median age was 80 years. The tumors ranged in size from 9 to 30 mm in diameter (median, 18 mm). The median follow-up interval was 55 months. The 3-year overall survival rate was 83.3% (95% confidence interval (CI) 71.1-90.7%) for all the patients and 94.7% (95% CI 68.1-99.2%) for the patients younger than 75 years. Local failure, regional lymph node metastases and distant metastases occurred in 4 (6.4%), 3 (4.8%) and 11 (17.7%) patients, respectively. Grades 3 and 4 toxicities were observed in 8 (12.9%) patients and 1 (1.6%) patient, respectively. No grade 5 toxicities were observed. CONCLUSIONS SBRT is safe and effective for patients with small lung lesions clinically diagnosed as primary lung cancer that satisfied the proposed strict indication criteria as previously reported. A prospective interventional study is required to ascertain if SBRT is an alternative strategy for these patients.
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Affiliation(s)
- Tetsuya Inoue
- Department of Radiation Oncology, Hokkaido University Hospital, Japan; Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Japan.
| | - Norio Katoh
- Department of Radiation Oncology, Hokkaido University Hospital, Japan; Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Japan
| | - Yoichi M Ito
- Department of Biostatistics, Hokkaido University Graduate School of Medicine, Japan
| | - Tomoki Kimura
- Department of Radiation Oncology, Hiroshima University Hospital, Japan
| | - Yasushi Nagata
- Department of Radiation Oncology, Hiroshima University Hospital, Japan
| | - Kengo Kuriyama
- Department of Radiology, University of Yamanashi Graduate, School of Medical Science, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi Graduate, School of Medical Science, Japan
| | - Tadamasa Yoshitake
- Department of Clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Japan
| | - Yoshiyuki Shioyama
- Department of Clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Japan
| | - Yusuke Iizuka
- Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Hospital, Japan
| | - Koji Inaba
- Department of Radiation Oncology, National Cancer Center, Japan
| | - Koji Konishi
- Department of Radiation Oncology, Osaka International Cancer Institute, Japan
| | - Masaki Kokubo
- Department of Radiation Oncology, Kobe City Medical Center General Hospital, Japan
| | - Katsuyuki Karasawa
- Department of Radiation Oncology, Tokyo Metropolitan Komagome Hospital, Japan
| | - Takuyo Kozuka
- Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Japan
| | - Kensuke Tanaka
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences, Japan
| | | | - Ichiro Kinoshita
- Department of Medical Oncology, Faculty of Medicine and Graduate School of Medicine Hokkaido University, Japan
| | - Hiroki Shirato
- Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Japan; Department of Radiation Medicine, Hokkaido University Faculty of Medicine, Japan
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Onimaru R, Shirato H, Shibata T, Hiraoka M, Ishikura S, Karasawa K, Matsuo Y, Kokubo M, Shioyama Y, Matsushita H, Ito Y, Onishi H. Phase I study of stereotactic body radiation therapy for peripheral T2N0M0 non-small cell lung cancer with PTV < 100 cc using a continual reassessment method (JCOG0702). Radiother Oncol 2015; 116:276-80. [DOI: 10.1016/j.radonc.2015.07.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 07/01/2015] [Accepted: 07/16/2015] [Indexed: 12/25/2022]
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