Peter Greer, PhD

Preventing Radiation Treatment Errors

Peter Greer, PhD, and his team at Calvary Mater Newcastle Hospital and the University of Newcastle, Australia, have developed the WatchDog system that monitors dose delivery in real time for radiation therapy patients and can prevent errors. The system uses imaging equipment that is present on all linear accelerators and could have a major impact on radiation oncology safety and accuracy.

With the grant from ROI, Dr. Greer and his team:

• Implemented and tested the WatchDog system, which uses images captured by EPID to determine treatment delivery accuracy in real time. 
• Performed real-time patient treatment verification.
• Acquired real-time patient verification data at multiple institutions. Optimized the system for error detection.

Additional Research

Since the completion of the ROI grant:

• The National Health and Medical Research Council (Australian Government) awarded Dr. Greer $593,742 (AUD, approximately $450,000 USD) over three years for continued testing of the WatchDog system. 
• Testing of the WatchDog system has continued and expanded to Memorial Sloan Kettering Cancer Center, NY, United States, University of Manitoba, Winnipeg, Canada, Royal North Shore Hospital, Sydney, Australia and Calvary Mater Newcastle, Newcastle, Australia.
• Development of a new version that will be able to be used clinically is underway.

Publications

• A Novel and Independent Method for Time-Resolved Gantry Angle Quality Assurance for VMAT was published July 13, 2017, in Journal of Applied Clinical Medical Physics. 
• Commissioning and Quality Assurance for VMAT Delivery Systems: An Efficient Time-Resolved System Using Real-Time EPID Imaging was published May 31, 2017, in Medical Physics. 
• A Method for Evaluating Treatment Quality Using In Vivo EPID Dosimetry and Statistical Process Control in Radiation Therapy was published March 13, 2017, in International Journal of Health Care Quality Assurance.
• An EPID-Based System for Gantry-Resolved MLC Quality Assurance for VMAT was published September 8, 2016, in Journal of Applied Clinical Medical Physics. 
• Investigation of a Real-Time EPID-based Patient Dose Monitoring Safety System Using Site-Specific Control Limits was published in Radiation Oncology on August 12, 2016. 
• First Experience with Real-Time EPID Based Delivery Verification During IMRT and VMAT Treatments was published in the November 1, 2015, issue of the International Journal of Radiation Oncology, Biology, Physics.
• A Cine-EPID Based Method for Jaw Detection and Quality Assurance for Tracking Jaw in IMRT/VMAT treatments was published in the February 2015 issue of Physica Medica.
• Dose-to-Water Conversion for the Backscatter-Shielded EPID: A Frame-Based Method to Correct for EPID Energy Response to MLC Transmitted Radiation was published July 25, 2014, in Medical Physics. 
• Simulation of Real-Time EPID Images During IMRT Using Monte-Carlo was published in the May 2014 issue of Physica Medica.
• An Independent System for Real-Time Dynamic Multileaf Collimation Trajectory Verification Using EPID was published December 12, 2013, in Physics in Medicine and Biology. 
• A System for EPID-based Real-Time Treatment Delivery Verification During Dynamic IMRT Treatment was published August 9, 2013, in Medical Physics. 
• Gantry-angle Resolved VMAT Pretreatment Verification Using EPID Image Prediction was published July 13, 2013, in Medical Physics. 

Presentations

• WatchDog: A Feasibility Study to Monitor Respiratory Motion for Liver/Lung Cancer Patients was presented at the 2018 American Association of Physicists in Medicine (AAPM) meeting. 
• Sensitivity Analysis of Action Limits for Real-Time EPID-Based Delivery Verification System Using Artificial Clinical Relevant Error Simulations was presented at the 2016 American Association of Physicists in Medicine (AAPM) meeting.
• Free Information-EPID-Based In Vivo Dosimetry invited presentation at the 2016 AAPM meeting.
• Simulation of Clinical Relevance Errors Detected by Real-time EPID-based Patient Verification System was presented at ESTRO 35. 
• EPID Dosimetry: Pre-Treatment Verification, Clinical Trial Credentialling and Real-Time Patient Dose Monitoring was presented at the 2015 Engineering and Physical Sciences in Medicine meeting in Wellington, New Zealand.
• Real-Time EPID-Based Dose Verification System for Detection of Gross Radiation Treatment Delivery Errors was presented at the 2013 ASTRO Annual Meeting.