S2860
RTT - RTT education, training, and advanced practice
ESTRO 2026
and without IRIS reconstruction was retrospectively evaluated. Material/Methods: Two analyses were performed. Firstly, CBCT acquisition parameters were assessed to define the optimal parameters. Four presets were tested, of which the parameters are shown in figure 1. The AI- enhanced IRIS reconstruction algorithm (Elekta) was applied to all presets. The different presets were tested in four patients with a tumor in the pelvis. Image quality was assessed visually by a multidisciplinary team consisting of two medical physicists, one medical physics engineer, and two RTTs with specific training in image-guided radiotherapy (IGRT). Secondly, the added value of IRIS reconstruction was assessed for contour adaptation in an online adaptive workflow. In this assessment, CBCTs from patients with prostate (n=1), anus (n=1), rectum (n=3), and bladder (n=2) were reconstructed with and without IRIS and blindly presented to a group of three RTTs who delineate contours during an online adaptive workflow, and was shown to one physician. The image quality of both reconstructions were assessed using a 5-point scale [2]. Additionally, participants identified their preferred reconstruction for delineation within an adaptive workflow and commented on the appearance of artifacts in the reconstructions. Results: The multidisciplinary team found that medium- and high-dose CBCTs provided the best image quality in the central pelvis, despite increased rind artifacts at the body contour from the higher dose per frame. These presets are applied based on pelvic body size. The lower-speed preset caused more artifacts in moving air regions. Based on the observations, medium and high-dose images with IRIS reconstruction were selected for further evaluation in the online adaptive workflow. Results are presented in Figure 2. Artifact assessment showed that IRIS reconstructions contained the same artifacts as without IRIS, appearing more pronounced in 48% of cases.
Conclusion: Consensus was reached that the medium- and high- dose CBCT presets, combined with IRIS reconstruction, were preferred for use in an online adaptive workflow. IRIS reconstruction modestly improves visualization of pelvic organs and was selected as the preferred reconstruction method for contour adaptation in
online adaptive workflows. Keywords: XVI, Cone-beam References: 1. Jonathan H Mason et al 2018 Phys. Med.
Biol.63 2250012. Precht et al 2019 Radiographers’ perspectives’ on Visual Grading Analysis as a scientific method to evaluate image quality. Radiography 25, S14–S18
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Enhancing patient comfort during MRI treatment planning for head and neck cancer using pre- simulation with a 3D-printed coil model Mia T Nguyen 1 , Zahraa Majid 1 , Emil D O’Sullivan 2 , Elisabeth L Juhl 1 , Anne K Due 1,3 , Ivan R Vogelius 1,4 1 Department of Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 2 Department of IT and Medical Technology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 3 Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 4 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Purpose/Objective: MRI treatment planning with mask fixation can be challenging forhead and neck cancer patients due todiscomfort from the narrow bore, mask fixation, coils, scan duration, and noise. These factors may lead to scan interruptions or the need for sedatives.This study investigates whether simulating MRI conditionsprior toscanningimprovespatient experienceand reducesint erruptions and need for sedatives. Material/Methods:
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