A new method for automatically determining the original isocenter in radiotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第9期
- Page:
- 1057-1062
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- A new method for automatically determining the original isocenter in radiotherapy
- Author(s):
- CHENG Long1; WU Haotian2; WEI Xiaowei3; QIN Hang1; JIANG Hongbing1; 4; SHI Feiyue3
- 1. Department of Clinical Medical Equipment, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China 2. Anhui Wisdom Technology Co.,Ltd, Hefei 230000, China 3. Radiation Therapy Center, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China 4. Nanjing Emergency Medical Center, Nanjing 210003, China
- Keywords:
- Keywords: radiotherapy original isocenter marked point CT image flooding algorithm threshold segmentation
- PACS:
- R318；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.09.001
- Abstract:
- Abstract: Objective To propose a method fo rautomatically determining the original isocenter in radiotherapy by delineating the structure of marked points (hereinafter referred to as the new method), and to test its application value by comparing it with the conventional method. Methods The CT images of 40 patients with abdominal tumors who received radiotherapy were selected, in which the marked points appeared in the first or second CT slices, 20 cases in each. The original isocenter was manually determined by conventional method through the cross positioning tool of Eclipse planning system, and then the new method was used to automatically determine the original isocenter by automatically delineating the structure of marked points and calculating the position.The difference of coordinates between the original isocenters determined by the two methods was analyzed. In addition, the structure of marked points was manually delineated. Results Compared with manually delineated structure of marked points, the Dice similarity index (DSC) value of marked points automatically delineated in the second CT slice in 20 cases was (0.79±0.06). The mean values of the absolute values of the deviations in 40 cases were 0.04 cm and 0.05 cm in the left-right direction (x-axis) and ventral-dorsal direction (y-axis), respectively. In the 20 cases with marked points appearing in the second CT slice, the mean, standard deviation, maximum and minimum values of the absolute values of z-axial (head-foot directional) deviations were 0.22, 0.03, 0.26 and 0.16 cm, respectively. Conclusion The proposed method can quickly and accurately calculate the original isocenter coordinates in radiotherapy. Especially when the marked points appear in the second CT slice, it can effectively make up for the defects of conventional methods.
Last Update: 2022-09-27