Henry C Woodruff1, Todsaporn Fuangrod2, Eric Van Uytven3, Boyd M C McCurdy3, Timothy van Beek3, Shashank Bhatia4, Peter B Greer5. 1. Faculty of Science and Information Technology, School of Mathematical and Physical Sciences, University of Newcastle, New South Wales, Australia. Electronic address: henry.woodruff@newcastle.edu.au. 2. Faculty of Engineering and Built Environment, School of Electrical Engineering and Computer Science, University of Newcastle, New South Wales, Australia. 3. Division of Medical Physics, CancerCare Manitoba, Winnipeg, Manitoba, Canada; Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada. 4. Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, New South Wales, Australia. 5. Faculty of Science and Information Technology, School of Mathematical and Physical Sciences, University of Newcastle, New South Wales, Australia; Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, New South Wales, Australia.
Abstract
PURPOSE: Gantry-mounted megavoltage electronic portal imaging devices (EPIDs) have become ubiquitous on linear accelerators. WatchDog is a novel application of EPIDs, in which the image frames acquired during treatment are used to monitor treatment delivery in real time. We report on the preliminary use of WatchDog in a prospective study of cancer patients undergoing intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) and identify the challenges of clinical adoption. METHODS AND MATERIALS: At the time of submission, 28 cancer patients (head and neck, pelvis, and prostate) undergoing fractionated external beam radiation therapy (24 IMRT, 4 VMAT) had ≥1 treatment fraction verified in real time (131 fractions or 881 fields). EPID images acquired continuously during treatment were synchronized and compared with model-generated transit EPID images within a frame time (∼0.1 s). A χ comparison was performed to cumulative frames to gauge the overall delivery quality, and the resulting pass rates were reported graphically during treatment delivery. Every frame acquired (500-1500 per fraction) was saved for postprocessing and analysis. RESULTS: The system reported the mean ± standard deviation in real time χ 91.1% ± 11.5% (83.6% ± 13.2%) for cumulative frame χ analysis with 4%, 4 mm (3%, 3 mm) criteria, global over the integrated image. CONCLUSIONS: A real-time EPID-based radiation delivery verification system for IMRT and VMAT has been demonstrated that aims to prevent major mistreatments in radiation therapy.
PURPOSE: Gantry-mounted megavoltage electronic portal imaging devices (EPIDs) have become ubiquitous on linear accelerators. WatchDog is a novel application of EPIDs, in which the image frames acquired during treatment are used to monitor treatment delivery in real time. We report on the preliminary use of WatchDog in a prospective study of cancerpatients undergoing intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) and identify the challenges of clinical adoption. METHODS AND MATERIALS: At the time of submission, 28 cancerpatients (head and neck, pelvis, and prostate) undergoing fractionated external beam radiation therapy (24 IMRT, 4 VMAT) had ≥1 treatment fraction verified in real time (131 fractions or 881 fields). EPID images acquired continuously during treatment were synchronized and compared with model-generated transit EPID images within a frame time (∼0.1 s). A χ comparison was performed to cumulative frames to gauge the overall delivery quality, and the resulting pass rates were reported graphically during treatment delivery. Every frame acquired (500-1500 per fraction) was saved for postprocessing and analysis. RESULTS: The system reported the mean ± standard deviation in real time χ 91.1% ± 11.5% (83.6% ± 13.2%) for cumulative frame χ analysis with 4%, 4 mm (3%, 3 mm) criteria, global over the integrated image. CONCLUSIONS: A real-time EPID-based radiation delivery verification system for IMRT and VMAT has been demonstrated that aims to prevent major mistreatments in radiation therapy.
Authors: Todsaporn Fuangrod; Peter B Greer; Benjamin J Zwan; Michael P Barnes; Joerg Lehmann Journal: J Appl Clin Med Phys Date: 2017-07-13 Impact factor: 2.102
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Authors: Jarad Martin; Paul Keall; Shankar Siva; Peter Greer; David Christie; Kevin Moore; Jason Dowling; David Pryor; Peter Chong; Nicholas McLeod; Avi Raman; James Lynam; Joanne Smart; Christopher Oldmeadow; Colin I Tang; Declan G Murphy; Jeremy Millar; Keen Hun Tai; Lois Holloway; Penny Reeves; Amy Hayden; Tee Lim; Tanya Holt; Mark Sidhom Journal: BMJ Open Date: 2019-08-20 Impact factor: 2.692
Authors: S B Lim; C J Tsai; Y Yu; P Greer; T Fuangrod; K Hwang; S Fontenla; F Coffman; N Lee; D M Lovelock Journal: Technol Cancer Res Treat Date: 2019-01-01
Authors: Todsaporn Fuangrod; Peter B Greer; Henry C Woodruff; John Simpson; Shashank Bhatia; Benjamin Zwan; Timothy A vanBeek; Boyd M C McCurdy; Richard H Middleton Journal: Radiat Oncol Date: 2016-08-12 Impact factor: 3.481