Author: Tianyuan Dai, Zejun Jiang, Xiangyue Kong 👨🔬
Affiliation: Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences 🌍
Purpose:
This study aims to evaluate the reliability of SFRT-VMAT plan verification by comparing two QA methods: Portal Dosimetry (PD) and Delta4®.
Methods:
Preteatment QA was conducted for 10 SFRT-VMAT plans using both PD and Delta4®. Gamma passing rates were calculated based on the 3%/3mm global criteria with a 90% threshold. Paired sample t-tests were performed to assess statistical differences between the two methods.
Results: The average gamma passing rates for PD and Delta4® were 95.1 ± 2.87% and 96.2 ± 3.45%, respectively. Delta4® demonstrated a slight but statistically significant advantage over PD in terms of gamma passing rates (p < 0.05) and provided higher verification accuracy. However, PD was more efficient and easier to implement in routine workflows.
Conclusion: Both PD and Delta4® are effective for SFRT-VMAT plan verification under the 3%/3mm criteria and 90% threshold. Delta4® is recommended for plans requiring higher dosimetric accuracy, while PD offers a faster alternative for routine QA processes.
Keywords: SFRT, VMAT, QA, Portal Dosimetry, Delta4®