Investigating the accuracy of dwell time of radioactive source in brachytherapy using MatriXX measurement(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第5期
- Page:
- 551-555
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Investigating the accuracy of dwell time of radioactive source in brachytherapy using MatriXX measurement
- Author(s):
- JIANG Fenfen; HU Benhui
- Department of Radiation Oncology, Jiangxi Maternal and Child Health Hospital, Nanchang 330006, China
- Keywords:
- Keywords: two-dimensional ion chamber matrix brachytherapy dwell time dwell distance
- PACS:
- R811.1；R318
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.05.005
- Abstract:
- Abstract: Objective To verify the accuracy of the dwell time of 192Ir radioactive source in brachytherapy by comparing the dwell time of 192Ir at different dwell point distances measured using two-dimension ion chamber matrix (MatriXX) with that calculated by treatment planning system. Methods The uterine tandems with different angles (15°, 30°, 45°) were pasted on the surface of MatriXX, respectively. Different plans with the treatment length of 10 cm were designed through treatment planning system (TPS). The weight and time of each dwell point were set to be equal. The plan was repeated 5 times, and meanwhile the data was recorded by MatriXX. Based on the requirements of brachytherapy, the dwell time at different dwell point distances (2.5, 5.0, 10.0 mm) was measured by MatriXX, and the experiments on the repeatability and accuracy of dwell time were also carried out. Results The relative deviation of the dwell time at different dwell point distances measured by MatriXX and that calculated by TPS was less than ±1%. Furthermore, when the dwell point distances were 2.5 mm and 10.0 mm, the maximum deviations of dwell time were 0.9% and 0.3%, respectively. Conclusion Within an appropriate dwell point distance range, using MatriXX to validate the repeatability and accuracy of dwell time of radioactive source in brachytherapy is feasible, reliable, economical and applicable. Moreover, the accuracy of dwell time measurement can be improved by selecting a larger dwell point distance.
Last Update: 2021-05-31