ESTRO 2024 - Abstract Book

S3942

Physics - Image acquisition and processing

ESTRO 2024

From the results obtained in this work, reconstructions using OncoFreeze AI show a significantly higher SUVmax and lower MTV than static case when dealing with small lesions that are influenced by the patient's breathing. This suggests that the use of OncoFreeze AI is a useful tool for better estimation of SUV, as it improves the delimitation of small lesions in the lungs or abdomen where respiratory motion has a greater influence on the image reconstruction.

Keywords: OncoFreeze, SUV, motion

References:

1. Nii T, Hosokawa S, Kotani T, et al. Evaluation of Data-Driven Respiration Gating in Continuos Bed Motion in Lung Lesions. J Nucl Med Technol 2023; 51:32-37 DOI: 10.2967/jnmt. 122.264909

2. Walton G, Linscheid L, Avery R, et al. OncoFreeze in 18F-FDG PET/CT image reconstructions resul in statistal uptake parameter deviation from non-OncoFreeze reconstructions lung lesions. Journal of Nuclear Medicine May 202, 61 (supplement 1) 3071

3. Van Elampt W, Hamill J, Jones J, et al. Optimal gating compared to 3D and 4D PET reconstruction for characterizacion of lung tumors. Eur J Nucl Med Mol Imaging 2011; 30:843-855

2654

Digital Poster

Clinical evaluation of CT number stability of advanced cone-beam CT for thorax and pelvic patients

Vicki T Taasti, Colien Hazelaar, Marta Bogowicz, Hendrik Hansen, Marije Velders, Anne van Engelen, Sjak Joosten, Angele Willems, Stephanie Huysmans, Wouter van Elmpt

Department of Radiation Oncology (MAASTRO), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, Netherlands

Purpose/Objective:

With the advent of online adaptive radiotherapy, the accuracy and speed of dose calculation become crucial. Historically, the usefulness of cone-beam CT (CBCT) images for dose distribution calculations has been limited by image artefacts and unstable CT numbers, leading to inaccuracies in CT-number-to-mass-density conversion. In this study, we assessed the image quality in terms of CT number stability of a new advanced CBCT imaging system (HyperSight, Varian Medical Systems) with rapid (5.9 seconds) acquisition, metal artifact reduction strategies, and advanced iterative reconstruction (IR).

Material/Methods: