Effects of iridium source dwell step size on three-dimensional brachytherapy plan of cervical cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第1期
- Page:
- 9-13
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of iridium source dwell step size on three-dimensional brachytherapy plan of cervical cancer
- Author(s):
- WU Ailin1; JIANG Xiao2; WU Aidong1; ZHU Lei2; LIU Yunqin1; QIAN Liting1
- 1. Department of Radiation Oncology, The First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital), Hefei 230001, China 2. School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- Keywords:
- Keywords: cervical cancer iridium source dwell step size three-dimensional brachytherapy dose
- PACS:
- R737.3；R817.8
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.01.002
- Abstract:
- Abstract: Objective To study the effect of iridium source dwell step size on plan evaluation and dose stability in the brachytherapy planning for cervical cancer. Methods Fifteen cervical cancer patients undergoing CT-guided high-dose-rate brachytherapy with iridium source applied by the Fletcher applicator in Anhui Provincial Cancer Hospital were enrolled in the study. Four kinds of plans with different dwell step sizes (Plan_1 mm, Plan_3 mm, Plan_5 mm and plan_7 mm) were created for each patient. The treatment duration as well as the parameters of target areas (D100, D90 and V100) and organs-at-risk (D2 cc and SF coefficient) were compared. The dose distribution with applicators shifting 3 mm to the feet was calculated, and the effects of the applicators shift on the dosimetric parameters of brachytherapy plans were analyzed under different dwell step sizes. Results There was no significant difference in dosimetric parameters of HRCTV among treatment plans with different step sizes (P>0.05). However, the D100, D90 and V100 of IRCTV and treatment duration of Plan_1 mm and Plan_3 mm were greater than those of Plan_5 mm, and the differences were statistically significant (P<0.05). The mean value and median value of SF coefficient of organs-at-risk in Plan_5 mm were smallest. After shifting applicators, the average decreases of the D90 of HRCTV and IRCTV in Plan_5 mm were minimum, which were 2.88% and 0.91%, respectively. Conclusion The appropriate iridium source dwell step size should be selected in the brachytherapy for cervical cancer, so that the treatment plan can not only fulfill the requirements of dose evaluation, but also has a certain dose delivery stability.
Last Update: 2022-01-17