Click here to


Are you sure ?

Yes, do it No, cancel

Changing Paradigms for Linac QA Using EPIDs and Beyond

B McCurdy1*, B Cai2*, T Pawlicki3*, (1) CancerCare Manitoba, Winnipeg, MB, (2) Washington University School of Medicine, St. Louis, MO, (3) UC San Diego, La Jolla, CA


(Tuesday, 7/31/2018) 2:45 PM - 3:45 PM

Room: Davidson Ballroom A

Continues efforts have been made to fully utilize the Electronic Portal Imaging Devices (EPID) for applications in medical linear accelerators’ (linacs) mechanical and dosimetric quality assurance (QA). With high spatial resolution, availability on most modern linacs, and great potential for test automation, EPID based QA have shown some promising results and benefits over traditional approaches. From linac acceptance tests to TG142 routine QA, EPID based measurements and associated image processing methodologies have been proposed and investigated by many medical physics groups. Most mechanical tests (EPID based Winston-Lutz test, MLC positional test, Jaw parallelism tests, etc.) and dosimetric tests (daily output constancy check, field flatness & symmetry tests, enhanced dynamic wedge measurement, etc.) have been successfully implemented with EPIDs by different groups. Several commercial solutions are also available targeting the EPID based linac QA. Prior to implementation of EPID based tests, it is crucial that physicists understand the benefits and limitations of EPIDs in this setting. EPID based linac QA offers an unprecedented degree of automation and standardization of QA procedures but EPIDs also suffer from a multitude of technical constraints which can potentially lead to misinterpretation of QA results and to suboptimal linac performance. This presentation is aimed at highlighting the emerging trends in EPID based linac QA, describing the challenges which can be experienced in this process and stimulating additional developments and research in this area.

Learning Objectives:
1. To provide a review and practical examples on use of EPID for routine linac QA
2. To discuss the role and opportunities of EPIDs for non-routine linac QA.
3. To describe processes and tools for rethinking linac QA, including how to analyze the AAPM TG-142 model, leverage data for driving decisions towards new paradigms in QA.



Not Applicable / None Entered.


Not Applicable / None Entered.

Contact Email