3D EPID-based in vivo dosimetry for IMRT and VMAT

In this paper the various approaches of EPID-based in vivo IMRT and VMAT dose verification, and their clinical implementation, are described. It will be shown that EPID-based in vivo dosimetry plays an important role in the total chain of verification procedures in a radiotherapy department. EPID-based dosimetry, in combination with in-room imaging, is a fast and accurate tool for 3D in vivo verification of VMAT delivery. EPID-based in vivo dosimetry provides clinically more useful information and is less time consuming than patient-specific pre-treatment dose verification. In addition to accurate 3D dose verification, in vivo EPID-based dosimetry will also detect major errors in the dose received by individual patients, and provides a safety net for advanced treatments such as IMRT and VMAT.