Evaluation of EBT-XD Radiochromic Films for High-Dose Radiotherapy patient specific Quality Assurance

Abstract

This study evaluates the performance of EBT-XD radiochromic films for patientspecific quality assurance (QA) in high-dose treatments such as Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). These films are ideal for measuring dose distribution due to their high resolution and energy independence. However, uncertainties may arise from interactions between the film and the scanning device. The objective of this research was to characterize the performance of EBT-XD films using an EPSON Expression 12000XL scanner in transmission mode. Key film parameters such as polarization effects, dose range, and calibration accuracy were analyzed. Results showed no significant polarization effects, and transmission mode provided better dose differentiation. Calibration was validated with less than 3% relative discrepancy for most test fields. The performance of EBT-XD films was compared with an electronic portal imaging device (EPID) across three clinical cases. The absolute gamma passing rate (PR) obtained was comparable or superior to the EPID, and the films offered a more comprehensive representation of the dose distribution, highlighting their value as an additional QA tool in highly modulated radiotherapy treatments.