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Use of Implanted Markers and Interportal Adjustment With Real-Time Tracking Radiotherapy System to Reduce Intrafraction Prostate Motion
| Title: | Use of Implanted Markers and Interportal Adjustment With Real-Time Tracking Radiotherapy System to Reduce Intrafraction Prostate Motion |
| Authors: | Shimizu, Shinichi Browse this author →KAKEN DB | | Osaka, Yasuhiro Browse this author | | Shinohara, Nobuo Browse this author →KAKEN DB | | Sazawa, Ataru Browse this author →KAKEN DB | | Nishioka, Kentaro Browse this author | | Suzuki, Ryusuke Browse this author →KAKEN DB | | Onimaru, Rikiya Browse this author →KAKEN DB | | Shirato, Hiroki Browse this author →KAKEN DB |
| Keywords: | Radiotherapy | | Prostate | | Intrafraction organ motion | | Image-guided radiotherapy |
| Issue Date: | 15-Nov-2011 |
| Publisher: | Elsevier |
| Journal Title: | International Journal of Radiation Oncology*Biology*Physics |
| Volume: | 81 |
| Issue: | 4 |
| Start Page: | e393 |
| End Page: | e399 |
| Publisher DOI: | 10.1016/j.ijrobp.2011.04.043 |
| PMID: | 21658857 |
| Abstract: | Purpose: Interportal adjustment was applied to patients with prostate cancer using three fiducial markers and two sets of fluoroscopy in a real-time tumor-tracking radiotherapy (RTRT) system. The incidence of table position adjustment required to keep intrafractional uncertainty within 2.0 mm was investigated in this study. Methods and Materials: The coordinates of the center of gravity of the three fiducial markers were measured at the start of every portal irradiation in intensity-modulated radiotherapy (IMRT) with seven ports. The table position was adjusted to the planned position if the discrepancy was larger than 2.0 mm in the anterior-posterior (AP), cranial-caudal (CC), or left-right (LR) directions. In total, we analyzed 4541 observations in 20 patients who received 70 Gy in 30 fractions (7.6 times a day in average). Results: The incidence of table position adjustment at 10 minutes from the initial set-up of each treatment was 14.2%, 12.3%, and 5.0% of the observations in the AP, CC, and LR directions, respectively. The accumulated incidence of the table position adjustment was significantly higher at 10 minutes compared to that at 2 minutes for AP (p = 0.0033) and CC (p = 0.0110) but not LR (p = 0.4296). An adjustment greater than 5 mm was required at least once in the treatment period in 11 (55%) patients. Conclusions: Interportal adjustment of table position was required in more than 10% of portal irradiations during the 10-minute period after initial setup to maintain treatment accuracy within 2.0 mm. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/50755 |
| Appears in Collections: | 医学院・医学研究院 (Graduate School of Medicine / Faculty of Medicine) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 清水 伸一
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