Paper Title
Linac Quality Assurance Software

Abstract
For radiotherapy, quality assurance is necessary to provide precise and accurate radiation treatment. Besides treatment plans and patient positioning, machine status is another vital issue that affects radiotherapy. In this article, we perform Linear Accelerator (Linac) quality assurance (QA) software based on MATLAB. All dates and images which were used in this article were taken by Linac of radiation therapy department of University Clinic of Erlangen. We have tested the accuracy of beam isocenter, conformity of light field and irradiation field, multileaf collimator (MLC) leakage and dynamic MLC positions relative to rotation, and in this article we will include the results of these tests and analyze machine status by parameters mentioned above. Finally, we will discuss about the validity of existing machine quality assurance program. Keywords - linear accelerator, quality assurance, image processing, multileaf collimator, light field, irradiation field