@article{oai:niigata-u.repo.nii.ac.jp:00028534,
 author = {笹本, 龍太 and 宇都宮, 悟 and 早川, 岳英},
 issue = {1},
 journal = {新潟大学保健学雑誌, 新潟大学保健学雑誌},
 month = {Mar},
 note = {放射線治療の呼吸同期照射において，同期信号の発生からビームオン・オフまでには遅延時間（time\ndelay）がある．今回，time delayの計測に適した動体ファントムの運動パターンと，新潟大学医歯学総合病院の呼吸同期照射システムにおけるtime delayを明らかにすることを目的として検討を行った．動体ファントムの運動波形はサイン波形と等速波形とし，運動幅は30 mmとした．ラジオクロミックフィルムを動体ファントムに乗せ，直径4 mm coneで連続照射を行ったところ，フィルム上の照射陰影はサイン波形で31.7±0.2mm，等速波形で30.4±0.1 mmであり，等速波形の方が実際の運動幅に近く，測定精度が高かった．次に等速波形を用いた10-40%位相の同期照射を行い，照射陰影の長さを理論値と比較したところ，time delayはビームオンで0.11±0.01秒，ビームオフで0.07±0.00秒であった．, In respiratory gated radiotherapy, there are time delays between the target entering the gated region and treatment beam on, and between the target exiting the gated region and treatment beam off. The aim of this study was to clarify the appropriate motion profile of motion phantom for measuring the time delays, and to measure the beam on and beam off time delays in respiratory gated radiotherapy system at Niigata University Medical and Dental Hospital. We irradiated radiochromic films on the motion phantom using 4 mm diameter cone without gating. As a motion profile for the motion phantom　(motion width: 30.0 mm), a sinusoidal profile and a constant velocity profile ware used. Measured length of the exposure streaks on the films were more accurate with the constant velocity profile than those with the sinusoidal profile (30.4±0.1 mm vs. 31.7±0.2 mm). Then we used the constant velocity profile for gating irradiation with a gating phase range of 10-40%, and compared the exposure streak length with a theoretical value. The calculated beam on time delay was 0.11±0.01 sec, and the beam off time delay was 0.07±0.00 sec.},
 pages = {9--15},
 title = {新潟大学医歯学総合病院の呼吸同期照射システムにおけるTime Delayの検討},
 volume = {14},
 year = {2017}
}