Abstract:Objective To study effect of simulated respiratory movement on dose distribution of different single dose stereotactic body radiotherapy (SBRT). Methods Twenty patients with SBRT of lung cancer with a maximum diameter of 5 cm were selected from the Cancer Center in People′s Hospital of Wuhan University from January to June 2018. Seven-field three-dimensional conformal and intensity-modulated conformal plans were designed for each lung cancer patient. The single dose of 200, 400, 600, 800, 1000 cGy was studied respectively. A two-dimensional semiconductor array Mapchecker produced by Sunnuclear Company in the United States was placed on a moving plate. The approximate motion period T was 3.5 s, which was similar to the normal breathing cycle. The range of motion was ±5, ±10, ±15 mm. Horizontal dose distribution at the corresponding isocentric output of the treatment planning system under simulated respiratory motion and static state and the difference between the measured dose distribution and the measured dose distribution were compared. Results There were significant differences in three-dimensional conformal and intensity-modulated conformal radiotherapy (3%/3 mm) pass rates between SBRT with different movement ranges and different single dose (P < 0.01). Conclusion Respiratory movement can reduce the conformity of dose in tumor target area and make the dose distribution blurred. It is easy to analyze the effect of respiratory movement on dose distribution of 3DCRT by Mapchecker system software, which mainly concentrates on the head and foot direction of target area, and can affect IMRT in the whole target area. The same range of motion is distributed with single dose. The dose distribution of IMRT is higher than that of three dimensional conformation.
阮长利 宋启斌▲ 李祥攀▲ 付敬国 郑永法. 模拟呼吸运动对SBRT剂量分布的影响研究[J]. 中国医药导报, 2019, 16(17): 76-79.
RUAN Changli SONG Qibin▲ LI Xiangpan▲ FU Jingguo ZHENG Yongfa . Effect research of simulated respiratory movement on dose distribution of SBRT. 中国医药导报, 2019, 16(17): 76-79.