PURPOSE: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient. METHODS: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance. RESULTS: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s). CONCLUSIONS: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.
PURPOSE: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient. METHODS: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance. RESULTS: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s). CONCLUSIONS: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.
Authors: Jacqueline M Andreozzi; Rongxiao Zhang; Adam K Glaser; Lesley A Jarvis; Brian W Pogue; David J Gladstone Journal: Med Phys Date: 2015-02 Impact factor: 4.071
Authors: Bin Cai; S Murty Goddu; Sridhar Yaddanapudi; Douglas Caruthers; Jie Wen; Camille Noel; Sasa Mutic; Baozhou Sun Journal: J Appl Clin Med Phys Date: 2017-11-10 Impact factor: 2.102
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
Authors: Benjamin J Zwan; Michael P Barnes; Todsaporn Fuangord; Cameron J Stanton; Daryl J O'Connor; Paul J Keall; Peter B Greer Journal: J Appl Clin Med Phys Date: 2016-09-08 Impact factor: 2.102