Effects of respiratory motion on target volume and center shift in 4DCT scan(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第3期
- Page:
- 277-282
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of respiratory motion on target volume and center shift in 4DCT scan
- Author(s):
- CHEN Kan1; YANG Zhen2; CAO Ying2; LI Shuzhou2; ZHANG Zijian2; YANG Xiaoyu2; SHAO Qigang2; LEI Mingjun2; TANG Du2; GONG Xueyu1
- 1. School of Nuclear Science and Technology, University of South China, Hengyang 421001, China 2. Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, China
- Keywords:
- Keywords: lung cancer four-dimensional computed tomography respiratory motion curve phantom internal target volume average intensity projection maximum intensity projection
- PACS:
- R318；R815.6
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.03.003
- Abstract:
- Abstract: Objective To study the changes in target volume and center shift in 4DCT image caused by the frequency and amplitude of tumor motion. Methods A small ball with a diameter of 2 cm was driven by a homemade human thorax model and respiratory platform to move sinusoidally, with the periods of 3.0, 3.8, 6.0 s, and the amplitudes of 1, 2 cm, for simulating the tumor motion in lung, and then 4DCT scan was carried out. The gross target volume (GTV) from 10 phases of each group of 4DCT image was segmented, and the obtained GTV was fused to obtain internal gross target volume (ITV). Furthermore, ITVAIP and ITVMIP were obtained by the automatic target segmentation based on maximum intensity projection (MIP) and average intensity projection (AIP). The relationships between GTV and the actual volume of the ball, between the GTV or GTV center shift and the frequency or amplitude of ball motion, between ITVP, ITVMIP or ITVAIP and the volume covering ball motion scope VP (theoretical ITV) were analyzed. Results There was no correlation between GTV and the velocity of the small ball at the corresponding phase, but the center shift was weakly correlated to the velocity of the small ball. The larger velocity of small ball was, the larger GTV center shift was. ITV and PTV were only related to the amplitude of tumor motion, and had no correlation with the period of tumor motion. Compared with ITVAIP which was smaller than the theoretical ITV, ITVMIP and ITVP were closer to the theoretical ITV. Conclusion Respiratory training and deep inspiration breath-hold or other respiratory management methods for the patient scheduled for thoracoabdominal tumor radiotherapy are conducive to improve the accuracy of radiotherapy. ITV segmented based on MIP can reflect the motion of tumor better.
Last Update: 2022-03-28