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Koike Y, Sumida I, Mizuno H, Shiomi H, Kurosu K, Ota S, Yoshioka Y, Suzuki O, Tamari K, Ogawa K. Dosimetric impact of intra-fraction prostate motion under a tumour-tracking system in hypofractionated robotic radiosurgery. PLoS One 2018; 13:e0195296. [PMID: 29621319 PMCID: PMC5886484 DOI: 10.1371/journal.pone.0195296] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 03/20/2018] [Indexed: 11/19/2022] Open
Abstract
For CyberKnife-mediated prostate cancer treatment, a tumour-tracking approach is applied to correct the target location by acquiring X-ray images of implanted fiducial markers intermittently. This study investigated the dosimetric impact of intra-fraction prostate motion during CyberKnife treatment. We retrospectively analyzed 16 patients treated using the CyberKnife (35 Gy delivered in five fractions). Using log files of recorded prostate motion, the intra-fraction prostate motion was simulated. We defined the worst-case intra-fraction prostate motion as the difference between pre- and post-deviation on log files and shifted structure sets according to the corresponding offsets for each beam. The dose-volume indices were calculated and compared with the original plan in terms of clinical target volume (CTV), planning target volume (CTV plus a 2-mm margin), rectum, bladder, and urethra. Prostate motions of >3, >5, and >10 mm were observed for 31.3, 9.1, and 0.5% of the 1929 timestamps, respectively. Relative differences between the simulated and original plans were mostly less than 1%. Although significant decreases were observed in D50% and D98% of the target, absolute dose differences were <0.1 Gy compared with the planned dose. The dosimetric impact of intra-fraction prostate motion may be small even with longer treatment durations, indicating that the tumour tracking using the CyberKnife could be a robust system for examining prostate motion.
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Affiliation(s)
- Yuhei Koike
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Iori Sumida
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hirokazu Mizuno
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hiroya Shiomi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Miyakojima IGRT Clinic, Miyakojima-ku, Osaka, Japan
| | - Keita Kurosu
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Radiology, Osaka University Hospital, Suita, Osaka, Japan
| | - Seiichi Ota
- Department of Radiology, Osaka University Hospital, Suita, Osaka, Japan
| | - Yasuo Yoshioka
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Osamu Suzuki
- Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Keisuke Tamari
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Kurosu K, Sumida I, Shiomi H, Mizuno H, Yamaguchi H, Okubo H, Tamari K, Seo Y, Suzuki O, Ota S, Inoue S, Ogawa K. A robust measurement point for dose verification in delivery quality assurance for a robotic radiosurgery system. JOURNAL OF RADIATION RESEARCH 2017; 58:378-385. [PMID: 27811201 PMCID: PMC5440860 DOI: 10.1093/jrr/rrw103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/28/2016] [Indexed: 05/17/2023]
Abstract
In this CyberKnife® dose verification study, we investigated the effectiveness of the novel potential error (PE) concept when applied to the determination of a robust measurement point for targeting errors. PE was calculated by dividing the differences between the maximum increases and decreases in dose distributions by the original distribution after obtaining the former by shifting the source-to-axis and off-axis distances of each beam by ±1.0 mm. Thus, PE values and measurement point dose heterogeneity were analyzed in 48 patients who underwent CyberKnife radiotherapy. Sixteen patients who received isocentric dose delivery were set as the control group, whereas 32 who received non-isocentric dose delivery were divided into two groups of smaller PE (SPE) and larger PE (LPE) by using their median PE value. The mean dose differences (± standard deviations) were 1.0 ± 0.9%, 0.5 ± 1.4% and 4.1 ± 2.8% in the control, SPE and LPE groups, respectively. We observed significant correlations of the dose difference with the PE value (r = 0.582, P < 0.001) and dose heterogeneity (r = 0.471, P < 0.001). We concluded that when determining a robust measurement point for CyberKnife point dose verification, PE evaluation was more effective than the conventional dose heterogeneity-based method that introduced optimal measurement point dose heterogeneity of <10% across the detector.
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Affiliation(s)
- Keita Kurosu
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Radiology, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Iori Sumida
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Corresponding author. Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. Tel: +81-6-6879-3482; Fax: +81-6-6879-3489;
| | - Hiroya Shiomi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hirokazu Mizuno
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroko Yamaguchi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hirofumi Okubo
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Keisuke Tamari
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yuji Seo
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Osamu Suzuki
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Seiichi Ota
- Department of Radiology, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shinichi Inoue
- Department of Radiology, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Okamoto H, Hamada M, Sakamoto E, Wakita A, Nakamura S, Kato T, Abe Y, Takahashi K, Igaki H, Itami J. Log-file analysis of accuracy of beam localization for brain tumor treatment by CyberKnife. Pract Radiat Oncol 2016; 6:e361-e367. [PMID: 27053497 DOI: 10.1016/j.prro.2016.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 12/20/2015] [Accepted: 01/20/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE The CyberKnife system generates log-files including actual treatment parameters for each procedure. In this study, log-files were analyzed to evaluate the mechanical uncertainty in beam localization over the long term (approximately 1 year), as were patterns of patient movements during brain tumor treatments using CyberKnife. METHODS AND MATERIALS The clinical to planning target volume (CTV-PTV) margin in clinical use was examined based on this analysis. Log-file analysis was performed using data from 140 brain tumor patients (267 treatment plans; 27,166 beams; approximately 66 beams/fraction), who underwent CyberKnife stereotactic radiosurgery and radiation therapy. We calculated a mean error and 2 standard deviations (2σ) for this population. Additionally, we calculated the radius R95% spatially covering 95% of all error vectors. RESULTS The mean mechanical uncertainties of CyberKnife brain tumor treatment were found to be 0.07, 0.01, and -0.09 mm in the +inferior/-superior, +left/-right, and +anterior/-posterior directions, respectively. The mean (2σ) of R95% was 1.02 (0.42) mm. A smaller degree of correlation between patient movement and R95% was observed. CONCLUSION The CyberKnife is robust in tracking accuracy, regardless of patient movement. The effectiveness of log-file analysis was demonstrated regarding quality control for monitoring beam localization in the CyberKnife system. The CTV-PTV margin of 2.0 mm was found to be adequate in brain tumor treatments using the CyberKnife.
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Affiliation(s)
- Hiroyuki Okamoto
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan.
| | - Minoru Hamada
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Emi Sakamoto
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Akihisa Wakita
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Satoshi Nakamura
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Toru Kato
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Yoshihisa Abe
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Kana Takahashi
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Hiroshi Igaki
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo Japan
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