https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7620 Sat 24 Mar 2018 08:34:43 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7127 10% of maximum, in-field signal). Using the continuous acquisition mode, the EPID response was not linear with dose. It was found that the continuous mode dose response corresponded approximately to dropping one image per acquisition session. Reproducibility of EPID response to low monitor units (MUs) was found to be poor but greatly improved with increasing MU. Open field profiles were found to be stable in the cross-plane direction but required several frames to become stable in the in-plane direction. However, both of these issues are clinically insignificant due to arc-IMRT deliveries requiring relatively large monitor units (>100 MU). Analysis of the five IMRT, arc, and arc-IMRT tests revealed that all examples compared to within 2% of maximum dose for more than 95% of in-field pixels. The continuous acquisition mode is suited to time-resolved dosimetry applications including arc-IMRT and dynamic IMRT, giving comparable dose results to the well-studied integrated acquisition mode, although caution should be used in low MU applications. Time-resolved EPID dose information also compared well to time-resolved ion-chamber measurements.]]> Sat 24 Mar 2018 08:34:10 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:19879 10% maximum field dose) for each case, over all fields. Conclusions: This work presents the first validation of the integration of a comprehensive fluence model with a patient and EPID radiation transport model that accounts for patient transmission, including complex factors such as patient scatter and the energy response of the a-Si detector. The portal dose image prediction model satisfies the 3% and 3 mm criteria for IMRT fields delivered to slab phantoms and could be used for patient treatment verification.]]> Fri 10 Nov 2023 15:59:41 AEDT ]]>