Application of thimble ionization chamber in point dose verification of brachytherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第5期
- Page:
- 506-512
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Application of thimble ionization chamber in point dose verification of brachytherapy
- Author(s):
- YANG Feng1; 2; WANG Xianliang2; QI Guohai2; LIU Min2; LI Jie2; KANG Shengwei2; FENG Xi2; LIU Mingzhe1
- 1. School of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China;
2. Sichuan Cancer Hospital & Institute, Chengdu 610041, China
- Keywords:
- ; Keywords: cervical cancer; thimble ionization chamber; brachytherapy; dose verification; planning system
- PACS:
- R312；R144.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.05.003
- Abstract:
- Abstract: Objective To explore the approach and feasibility of using a thimble ionization chamber to carry out dose verification of brachytherapy. Methods The self-made phantom was scanned with CT and the obtained images were imported into Oncentra V4.3 planning system. The region of interest which plotted on the planning system was defined as the sensitive volume of the thimble ionization chamber and the average dose of the region of interest was considered as the dose at the measurement point. This experiment for the dose verification of brachytherapy mainly includes two parts. (1) The simple plans for source applicators, including single-tube, double-tube and three-pipe, were made for the self-made phantom with the use of Oncentra V4.3 system, and then the self-made phantom were irradiated for dose measurements. Finally, the dose deviations between the average dose and the measured values were compared. (2) The treatment plans of 21 patients were selected. With the corresponding source applicators and dwelling positions of the self-made phantom, the dwelling time in the treatment plans of patients was adopted for the calculation and measurement. Finally, the dose deviations between the average dose and the measured value were compared. Results The maximum deviation between the calculated values of the planning system and the measured values of the thimble ionization chamber was -3.5%. The deviations between the measured value and the calculated values in 21 patients were all less than 5%. Conclusion Thimble ionization chamber can be used for the point dose verification of brachytherapy.
Last Update: 2019-05-23