Dose variation caused by respiratory motion on SBRT for lung tumors: an analysis based on 4DCT and deformable registration(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第12期
- Page:
- 1406-1410
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dose variation caused by respiratory motion on SBRT for lung tumors: an analysis based on 4DCT and deformable registration
- Author(s):
- WU Wenjing1; LI Yi2; SUN Xuanzi2; ZHANG Xiaozhi2; SUN Leihuan1; ZHANG Bin1; LI Junjun3
- 1. Department of Radiological Health, Xi’an Center for Disease Control and Prevention, Xi’an 710054, China; 2. Department of Radiation Oncology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China; 3. Department of Medical Imaging, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
- Keywords:
- Keywords: lung tumor; four-dimensional computed tomography; deformable registration; respiratory motion curve; stereotactic body radiotherapy; dosage
- PACS:
- R811.1；R734.2
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.12.008
- Abstract:
- Abstract: Objective To discuss the effects of respiration motions on the doses to tumors and organs-at-risk in patients receiving stereotactic body radiotherapy for lung tumors in the lower lobe. Methods Fourteen patients with lung tumors in the lower lobe underwent plain CT scans and four-dimensional CT (4DCT) scans to acquire plain scanning image and sequence images of 10 respiratory phases. The percentage of time intervals of each respiratory phase in a whole respiratory motion was calculated from respiratory motion curves recorded during radiotherapy. MIM workstation was used to delineate tumors and organs-at-risks. Treatment plan was designed based on plain CT, and then 3DCT plan was ported to sequence images of each respiratory phase for dose calculation by accumulating doses based on the percentages of time intervals of each respiratory phase. Results The 4D weighted dose accumulations of the mean dose of planning target volume, the V20 and mean dose of ipsilateral lung, the mean dose of contralateral lung and the mean dose of lungs were decreased by 2.37%, 5.08%, 5.19%, 3.61% and 3.46%, respectively, compared with 3D planned doses, with statistical differences (P<0.05). Conclusion The respiratory motions of patients result in decreased doses to tumors and lungs, but the variation is within a small range. The dose variation caused by respiratory motion on SBRT for lung tumors in the lower lobe can be more accurately evaluated by utilizing 4DCT and deformable registration and introducing the percentages of time intervals of each respiratory phase
Last Update: 2019-12-24