TU-D-BRC-02: Free Information - EPID-Based In Vivo Dosimetry.

There has been increased deployment of gantry-mounted linacs with onboard kilovoltage x-ray imagers. Despite this trend, most clinics still employ beam's-eye-view (BEV) imaging using flat panel electronic portal imaging devices (EPIDs) as a highly useful means of verifying geometric localization pre- and post-delivery. In recent years, there has been increased interest in the use of EPIDs for a variety of clinical and investigational applications ranging from megavoltage cone-beam CT, in vivo dosimetry, patient-specific QA to real-time target localization for dynamic MLC-based tumor tracking. In conjunction, there are several innovative EPID designs currently under investigation that hold great promise in bringing novel imaging and image-guidance applications into clinical practice. This symposium is aimed at clinical and research-oriented medical physicists who want to learn more about current and future megavoltage imaging technology and applications. In this symposium, we will examine the (i) interesting applications that make use of current EPID technology such as volumetric 4D image-based models, real-time position estimation for dynamic MLC tracking, etc., (ii) clinical applications such as in vivo EPID dosimetry and (iii) innovative high-performance EPID designs and exciting future applications, including designs based on thick segmented scintillators, hybrid kV/MV imagers using segmented strip scintillators, and energy-resolving EPIDs based on multilayer imagers and poly-Silicon active matrix flat panel imagers. Learning Objectives - In this symposium, the attendees will learn 1. Novel applications using currently available EPIDs 2. Use of EPIDs to perform in vivo dosimetry 3. Novel designs using high-efficiency, energy resolving EPIDs and future applications of megavoltage imaging J. Rottmann, Varian Medical SystemsP. Greer, Research Grant Funding from Radiation Oncology Institute (Grant ROI2013-912), 2013-2014.