Effects of bladder volume variation on doses to bladder and small bowel in postoperative radiotherapy for cervical cancer in different patient positioning: an analysis based on FBCT(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2023年第5期
- Page:
- 529-535
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of bladder volume variation on doses to bladder and small bowel in postoperative radiotherapy for cervical cancer in different patient positioning: an analysis based on FBCT
- Author(s):
- XU Chendi1; 2; JIANG Xiaobo2; WANG Yajuan2; LIU Biaoshui2; PENG Yinglin2; LIN Zhiyue2; LIN Chengguang2; WU Dehua1
- 1. Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China 2. Sun Yat-sen University Cancer Center/State Key Laboratory of Oncology in South China/Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
- Keywords:
- Keywords: cervical cancer radiotherapy bladder filling organs-at-risk radiotherapy positioning
- PACS:
- R737.33；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2023.05.001
- Abstract:
- Abstract: Objective To investigate the dosimetric effect of bladder volume variation on bladder and small bowel in postoperative radiotherapy for cervical cancer in different patient positioning using fan beam computed tomography (FBCT). Methods A total of 22 cervical cancer patients who received postoperative radiotherapy in Sun Yat-sen University Cancer Center were retrospectively analyzed, including 10 patients in prone position and 12 patients in supine position. Before the treatment, kV FBCT was performed with UIH uRT-linac 506c accelerator. FBCT images after translational correction were automatically contoured in the treatment planning system, and the original plan parameters were copied for dose calculation. The trend of bladder volume variations and its effects on doses to bladder and small bowel were analyzed. Results The bladder volume of 22 patients changed to varying degrees during treatment. The urination ability showed a decreasing trend with the treatment course. For patients in supine position, the rate of bladder volume variations had a low negative correlation with V45 change of bladder (r=-0.431), moderate negative correlations with V40 and V30 changes of bladder (r=-0.651, r=-0.780) and V45 and V40 changes of small bowel (r=-0.701, r=-0.794), and a high negative correlation with V30 change of small bowel (r=-0.871). For patients in prone position, the rate of bladder volume variation had low negative correlations with V30 change of bladder and V45 change of small bowel (r=-0.306, r=-0.336), and moderate negative correlations with V40 and V30 changes of small bowel (r=-0.505, r=-0.589). Conclusion It is difficult to maintain the consistency of inter-fraction bladder volume in postoperative radiotherapy for cervical cancer, and the doses to bladder and small bowel are more affected by bladder volume variation in supine position as compared with prone position.
Last Update: 2023-05-26