https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33853 Wed 04 Sep 2019 10:04:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34638 Patient: A patient with prostate adenocarcinoma undergoing SBRT with 36.25 Gy, delivered in 5 fractions was enrolled in the study. 6DoF KIM technology: 2D positions of three implanted gold markers in each of the kV images (125 kV, 10 mA at 11 Hz) were acquired continuously during treatment. The 2D → 3D target position estimation was based on a probability distribution function. The 3D → 6DoF target rotation was calculated using an iterative closest point algorithm. The accuracy and precision of the KIM method was measured by comparing the real-time results with kV-MV triangulation. Results: Of the five treatment fractions, KIM was utilised successfully in four fractions. The intrafraction prostate motion resulted in three couch shifts in two fractions when the prostate motion exceeded the pre-set action threshold of 2 mm for more than 5 s. KIM translational accuracy and precision were 0.3 ± 0.6 mm, −0.2 ± 0.3 mm and 0.2 ± 0.7 mm in the Left-Right (LR), Superior-Inferior (SI) and Anterior-Posterior (AP) directions, respectively. The KIM rotational accuracy and precision were 0.8° ± 2.0°, −0.5° ± 3.3° and 0.3° ± 1.6° in the roll, pitch and yaw directions, respectively. Conclusion: This treatment represents, to the best of our knowledge, the first time a cancer patient’s tumour position and rotation have been monitored in real-time during treatment. The 6 DoF KIM system has sub-millimetre accuracy and precision in all three translational axes, and less than 1° accuracy and 4° precision in all three rotational axes.]]> Thu 24 Mar 2022 11:35:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48039 Error). For simulated field size errors, the RMS_Error 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 ]]>