Phantom Dose Verification using EBT2 Radiochromic Films for Radiotherapy

• Main Authors: Ren Duen Lin, 林壬惇
• Other Authors: C. J. Tung
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/32687259384382970740

碩士 === 長庚大學 === 醫學影像暨放射科學系 === 100 === New and more complex radiotherapy techniques such as the intensity modulated radiation therapy (IMRT) and the RapidArc technique have been developed. This study demonstrates the feasibility of adopting EBT2 radiochromic film dosimetry for dose verification of IMRT and RapidArc treatments using an Epson Expression 10000XL color flatbed scanner and the FilmQA Pro software. Three handling techniques and two film characteristics were studied. The former are 1. with and without the scanning frame, 2. direction of the texture side of the film relative to the light source and 3. orientation of the film. The latter are film reproducibility and dose rate dependence. The results of the former show that the dose percentage difference was within 4.8% and -1.2%, for with and without the scanning frame and direction of the texture side of the film relative to the light source, respectively. The dose percentage difference of film orientation was within 35.1%, showing the operating process to maintain consistency was very important. The results of film reproducibility and dose rate dependence show that the percentage differences were within 2.6% and 1.5%, respectively. Applying the established EBT2 film dosimetry verification system for IMRT and RapidArc, the passing rates of gamma evaluation were 99.69% and 99.56%, respectively. Based on the results of this study, it is concluded that the EBT2 film dosimetry system can be used for phantom dose verification of IMRT and RapidArc.