Use of Amorphous Silicon (ASi) Electronic Portal Imaging Devices for Other applications for Linear Accelerator Quality Assurance

Introduction: The success of radiation therapy depends critically on the accuracy of patient alignment in treatment position day after day. The primary use for Electronic portal imaging devices (EPIDs) is to monitor patient position during daily radiotherapy sessions. Recently the role of EPIDs has been expanded beyond patient imaging to become a useful tool for radiotherapy dosimetry. Material and Methods: To test another application of linac quality assurance (QA), ۱۰×۱۰ cm۲ and ۱۸×۱۸ cm۲ images of an open field were obtained. The epidermis was located at a fixed detector distance of ۱۵۰ cm. Results: Wedge profile and wedge factors with a high level of accuracy demonstrated. The profiles acquired using EPID deviated in shape and magnitude by up to ۱۶% from the ion chamber profiles. The use of EPID for linac QA can be simplified by improving the available software analysis tools, which will increase its efficiency. According to the findings, the EPID aSi۵۰۰ has the potential to be used as a relative dosimeter, making it a straightforward and efficient tool for daily QA. Conclusion: All EPID measurements were performed using the linear accelerator Varian DMX. Based on the physical characteristics, as an efficient tool, the SLIC-EPID can be used for daily QA.

Keywords:

Portal imaging , dosimetric properties , Electronic Portal Imaging Devices (EPID) , Radiation Dosimetry