Effects of different degrees of bladder filling on brachytherapy for cervical cancer based on Monte Carlo simulation(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2017年第11期
- Page:
- 1096-1101
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of different degrees of bladder filling on brachytherapy for cervical cancer based on Monte Carlo simulation
- Author(s):
- HOU Lingtong1; WANG Zhi2; CHEN Zhi1; XU Xie1
- 1. College of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230025, China; 2. Department of Radiation Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
- Keywords:
- ; Keywords: cervical cancer; brachytherapy; degree of bladder filling; Monte Carlo method; voxel model
- PACS:
- R730.55；R815
- DOI:
- DOI:10.3969/j.issn.1005-202X.2017.11.004
- Abstract:
- Abstract: Objective To investigate the effects of different degrees of bladder filling on the dose distribution in brachytherapy for cervical cancer based on Monte Carlo simulation. Methods A Nucletron-mHDR-V1 192Ir radioactive source model was established with MCNP5 Monte Carlo particle transport software package, and then placed into a three-dimensional voxel model obtained from the conversion of CT images taken from a patient when he had different degrees of bladder filling. The prescription dose of brachytherapy was 60 Gy, and the reference points were selected according to ICRU 38 report. The single tube source device was used. The location of the radioactive source was divided into 18 steps and the distance of each step was 5 mm. Results The absorbed dose to reference point A was 60 Gy when the bladder filling was 54 mL or 328 mL. The absorbed doses to the reference points of the bladder and rectal were 30.21 Gy and 49.05 Gy at the bladder filling of 54 mL, and 33.59 Gy and 50.19 Gy at 328 mL; the absorbed doses to femoral head were found to be 6.33 Gy (left) and 6.39 Gy (right) at 54 mL, and 6.15 Gy (left) and 6.12 Gy (right) at 328 mL. The dose volume histogram of the bladder was obtained based on the absorbed doses in the voxels of bladder wall. When the bladder filling was 54 mL, V10, V20, V30, V40, V50, V60 were 100%, 39.69%, 26.20%, 17.89%, 14.48%, 11.69%, respectively; when the bladder filling was 328 mL, V10, V20, V30, V40, V50, V60 were 86.07%, 26.53%, 15.58%, 9.44%, 6.01%, 3.72%, respectively. Conclusion No significant differences were found in the absorbed dose to the reference points of the rectal and the femoral head between the bladder filling of 328 mL and that of 54 mL. Although the absorbed dose to the reference point of the bladder increased (3.38 Gy) at the bladder filling of 328 mL as comparison with 54 mL, the irradiated volume of the bladder was significantly reduced (the irradiated volume reduced by 13.16% when the dose was 20 Gy, 8.45% when the dose was 40 Gy, 7.97% when the dose was 60 Gy). The simulated results in this study provide some guidance for the brachytherapy of cervical cancer.
Last Update: 2017-11-23