Application of 3DCT and 4DCBCT in evaluating target margin in SABR for lung cancer in middle or lower lobe(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第4期
- Page:
- 426-430
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Application of 3DCT and 4DCBCT in evaluating target margin in SABR for lung cancer in middle or lower lobe
- Author(s):
-
LI Yi1; WU Wenjing2; ZHANG Yuemei1; ZHANG Jiadi1; ZHANG Xiaozhi1
- 1. Department of Radiation Oncology, the First Affiliated Hospital of Xian Jiaotong University, Xian 710061, China 2. Department of Radiological Health, Xian Center for Disease Control and Prevention, Xian 710054, China
- Keywords:
- Keywords: lung cancer four-dimensional cone-beam computed tomography stereotactic ablative radiotherapy planning target volume
- PACS:
- R734.2；R815
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.04.006
- Abstract:
- Abstract: Objective To obtain setup errors and errors caused by respiratory motion using four-dimensional cone-beam computed tomography (4DCBCT), thereby calculating planning target volume (PTV) margin in stereotactic ablative radiotherapy (SABR) for lung cancer in middle or lower lobe. Methods Nineteen patients who underwent SABR for lung cancer in middle or lower lobe were randomly selected for retrospective analysis. 4DCBCT scan was conducted before treatment, and a total of 72 images were obtained. According to the image registration between 4DCBCT and CT for positioning, the inter-fractional setup errors of target areas and errors caused by respiratory motion were evaluated, thereby determining the size of PTV margins. Results The setup errors were (0.11±0.29), (0.02±0.58) and (0.05±0.26) cm in right-left (RL), superior-inferior (SI) and anterior-posterior (AP) directions, respectively, and the errors caused by respiratory motion were (-0.06±0.34), (0.09±0.68) and (0.06±0.23) cm, respectively. The PTV margin calculated by the formula in ICRU83# report were 1.13, 2.15 and 0.90 cm in RL, SI and AP directions. Conclusion 4DCBCT can be used to effectively evaluate setup errors and errors caused by respiratory motion and to determine PTV margin in SABR for lung cancer in middle or lower lobe. Compared with the margin standard provided by Radiation Therapy Oncology Group, the PTV margin calculated by the proposed method is more accurate. The proposed method can be used to individually evaluate PTV margin.
Last Update: 2021-04-29