https://ogma.newcastle.edu.au/vital/access/manager/Index ${session.getAttribute("locale")} 5 Investigation of a modified electronic portal imaging device for improving dosimetry in radiotherapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:10089 Wed 11 Apr 2018 15:30:58 AEST ]]> Dosimetric properties of an amorphous silicon electronic portal imaging device for verification of dynamic intensity modulated radiation therapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:3152 Wed 11 Apr 2018 15:29:57 AEST ]]> An investigation of gantry angle data accuracy for cine-mode EPID images acquired during arc IMRT https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:17095 Wed 11 Apr 2018 15:05:03 AEST ]]> An improved Monte-Carlo model of the varian EPID separating support arm and rear-housing backscatter https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:17105 Wed 11 Apr 2018 14:38:42 AEST ]]> Software tool for portal dosimetry research https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:4540 Wed 11 Apr 2018 13:22:45 AEST ]]> Correction of pixel sensitivity variation and off-axis response for amorphous silicon EPID dosimetry https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:1528 Wed 11 Apr 2018 11:45:08 AEST ]]> Improvement of EPID-based techniques for dosimetry and investigation of linac mechanical performance in advanced radiotherapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:12130 Wed 11 Apr 2018 10:17:44 AEST ]]> Development of EPID-based real-time dosimetry and geometry in radiation therapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:12635 Wed 11 Apr 2018 09:46:24 AEST ]]> Time-resolved quality assurance and delivery verification for external beam radiation therapy using an electronic portal imaging device https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:38923 Wed 03 Apr 2024 14:21:55 AEDT ]]> Virtual EPID standard phantom audit (VESPA) for remote IMRT and VMAT credentialing https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:34305 Tue 26 Feb 2019 15:18:09 AEDT ]]> Insensitivity of machine log files to MLC leaf backlash and effect of MLC backlash on clinical dynamic MLC motion: An experimental investigation https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:52542 Tue 17 Oct 2023 10:18:54 AEDT ]]> EPID-based dosimetry to verify IMRT planar dose distribution for the aS1200 EPID and FFF beams https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:29751 Tue 16 Mar 2021 10:50:28 AEDT ]]> An EPID-based system for gantry-resolved MLC quality assurance for VMAT https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:25773 Tue 16 Mar 2021 10:50:09 AEDT ]]> A novel quality assurance procedure for trajectory log validation using phantom-less real-time latency corrected EPID images https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:46306 2 sliding window (SW) field moving at 2.5 cm/s orthogonal to the row readout direction. The latency of each panel type was determined by averaging the results of two panels of the same type. Geometric correction was achieved by computing leaf positions with respect to the projected isocenter position as a function of gantry angle. This was determined by averaging the central axis position of fields at two collimator positions of 90° and 270°. The radiological to physical leaf end position was determined by comparison of the measured gap with that determined using a feeler gauge. The radiological to physical leaf position difference was found to be 0.1 mm. With geometric and latency correction, the proposed method was found to be improve the ability to detect dynamic MLC positions from 1.0 to 0.2 mm for all leaves. Latency and panel residual geometric error correction improve EPID-based MLC position measurement. These improvements provide for the first time a trajectory log QA procedure.]]> Tue 15 Nov 2022 10:14:54 AEDT ]]> Impact of backscattered radiation from the bunker structure on EPID dosimetry https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:17097 Tue 04 Apr 2023 19:30:17 AEST ]]> Beam focal spot position: the forgotten linac QA parameter. An EPID-based phantomless method for routine Stereotactic linac QA https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:34143 Tue 03 Sep 2019 18:26:27 AEST ]]> A proposed method for linear accelerator photon beam steering using EPID https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:35008 Thu 30 May 2019 14:44:50 AEST ]]> An investigation of gantry angle data accuracy for cine-mode EPID images acquired during arc IMRT https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:19103 Thu 30 Jul 2015 09:51:11 AEST ]]> Investigation of a real-time EPID-based patient dose monitoring safety system using site-specific control limits https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:29628 Thu 27 Jan 2022 15:55:44 AEDT ]]> Toward real-time verification for MLC tracking treatments using time-resolved EPID imaging https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:48039 Error). For simulated field size errors, the RMSError was 0.47 cm2 and field shape changes were detected for random errors with standard deviation ≥ 2.5 mm. For clinical lung SABR deliveries, field location errors of 1.6 mm (parallel MLC motion) and 4.9 mm (perpendicular) were measured (expressed as a full-width-half-maximum). The mean and standard deviation of the errors in field size and shape were 0.0 ± 0.3 cm2 and 0.3 ± 0.1 (expressed as a translation-invariant normalized RMS). No correlation was observed between geometric errors during each treatment fraction and dosimetric errors in the reconstructed dose to the target volume for this cohort of patients. Conclusion: A system for real-time delivery verification has been developed for MLC tracking using time-resolved EPID imaging. The technique has been tested offline in phantom-based deliveries and clinical patient deliveries and was used to independently verify the geometric accuracy of the MLC during MLC tracking radiotherapy.]]> Thu 23 Mar 2023 10:25:03 AEDT ]]> An EPID based method for efficient and precise asymmetric jaw alignment quality assurance https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:7400 Sat 24 Mar 2018 11:14:02 AEDT ]]> Monte Carlo-based adaptive EPID dose kernel accounting for different field size responses of imagers https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:7816 Sat 24 Mar 2018 10:46:05 AEDT ]]> Direct-detection EPID dosimetry: investigation of a potential clinical configuration for IMRT verification https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:7317 Sat 24 Mar 2018 08:38:52 AEDT ]]> Evaluation of an a-Si EPID in direct detection configuration as a water-equivalent dosimeter for transit dosimetry https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:11207 Sat 24 Mar 2018 08:12:45 AEDT ]]> An independent system for real-time dynamic multileaf collimation trajectory verification using EPID https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:21332 Sat 24 Mar 2018 07:52:48 AEDT ]]> Improvement of Varian a-Si EPID dosimetry measurements using a lead-shielded support-arm https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:21545 Sat 24 Mar 2018 07:50:26 AEDT ]]> A cine-EPID based method for jaw detection and quality assurance for tracking jaw in IMRT/VMAT treatments https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:22659 Sat 24 Mar 2018 07:15:38 AEDT ]]> Commissioning and quality assurance for VMAT delivery systems: an efficient time-resolved system using real-time EPID imaging https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:33870 Mon 21 Jan 2019 10:42:48 AEDT ]]> A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:19934 Fri 20 Jul 2018 15:10:00 AEST ]]> EPID-based verification of the MLC performance for dynamic IMRT and VMAT https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:21588 Fri 20 Jul 2018 15:08:55 AEST ]]> Dose-to-water conversion for the backscatter-shielded EPID: a frame-based method to correct for EPID energy response to MLC transmitted radiation https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:19690 Fri 20 Jul 2018 15:04:41 AEST ]]> Development and testing of an improved dosimetry system using a backscatter shielded electronic portal imaging device https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:21566 Fri 10 Nov 2023 16:00:54 AEDT ]]> Characterization of optical transport effects on EPID dosimetry using Geant4 https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:19880 Fri 10 Nov 2023 15:59:12 AEDT ]]> Characterization of a novel EPID designed for simultaneous imaging and dose verification in radiotherapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:18991 Fri 10 Nov 2023 15:57:38 AEDT ]]> A method for removing arm backscatter from EPID images https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:19932 Fri 10 Nov 2023 15:57:09 AEDT ]]> First clinical experience with real-time portal imaging-based breath-hold monitoring in tangential breast radiotherapy https://ogma.newcastle.edu.au/vital/access/manager/Repository/uon:51352 , per tangent were compared to the planned mLDs; differences between the largest and smallest observed () per tangent were calculated. Results: For 56% (162/288) of the tangents tested, were outside the tolerance window. All but one patient had at least one fraction showing this behaviour. The largest difference found between an and its planned mLD was −16.9 mm. The accuracy of patient positioning and the quality of marker-block-based DIBH guidance contributed to the differences. Fractions with patient position verification using a single EPID image taken before treatment showed a lower rate (34%), suggesting reassessment of setup procedures. Conclusions: Real-time treatment monitoring of the internal anatomy during DIBH delivery of tangential breast RT is feasible and useful. The new system requires no additional radiation for the patient.]]> Fri 01 Sep 2023 13:36:10 AEST ]]>