Patient QA System Using Delta$^4$ Phantom for Tomotherapy: A Comparative Study with EBT3 Film

• Published in: Journal of the Korean Physical Society pp. 816 - 821
• Main Authors: 조신행, 고영문, 김찬규, 김학수, 정종휘, 이세병, 임영경, 신동호
• Format: Journal Article
• Language: English
• Published: 한국물리학회 01.04.2019
• Subjects: 물리학
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.74.816

In this study for delivery quality assurance (DQA) of helical tomotherapy, we compared the Delta$^4$ phantom system with the Gafchromic EBT3 film dosimetry system in eight cases and analyzed the global gamma-index passing rate (GPR) of various treatment sites in 109 cases. The mean GPR values for Delta$^4$ and EBT3 film were 98.8\% and 97.8\%, respectively. GPR values were similar between Delta$^4$ and film dosimetry, with a linear correlation factor of 72.4\%. About 70\% of the Delta$^4$ cases had GPR values greater than 99\%, although the GPR value was highly dependent on the clinical target size; GPR decreased approximately 3.7\% when the target size increased by 3 cm. The GPR results show that Delta$^4$ could be a better dosimetry tool than EBT3 film for tomotherapy DQA. KCI Citation Count: 0