ESTRO 2024 - Abstract Book

S3848

Physics - Image acquisition and processing

ESTRO 2024

emitters, most notably 12N (half-life 11 ms), which are present during the beam-off periods when the energy layer changes take place.

Keywords: PET imaging, range verification, HN cancer

References:

[1] Paganetti, H 2012 Range uncertainties in proton therapy and the role of Monte Carlo Simulations Phys. Med. Biol. 57 R99-R117

[2] Lomax, AJ 2020 Myths and realities of range uncertainty Br. J. Radiol. 93 20190582

[3] Ozoemelam I et al, 2020b Real-Time PET Imaging for Range Verification of Helium Radiotherapy Front. Phys. 8 565422

[4] Buitenhuis HJT et al, 2017 Beam-on imaging of short-lived positron emitters during proton therapy Phys. Med. Biol. 62 4654–4672

1583

Digital Poster

Phantom-based optimization of virtual monoenergetic image reconstruction in dual-energy CT

Anne Richter, Gary Razinskas, Stefan Weick, Paul Lutyj, Johannes Kraft, Andrea Wittig-Sauerwein

University Hospital Wuerzburg, Department of Radiation Oncology, Wuerzburg, Germany

Purpose/Objective:

Dual-energy computed tomography (DECT) has the potential to significantly improve tissue characterization and enhance target volume delineation accuracy in radiotherapy imaging for treatment planning [1]. Virtual monoenergetic image (VMI) reconstruction is an integral technique in DECT. This study aims to determine the optimal VMI reconstruction level that maximizes tissue contrast for delineation through rigorous phantom-based evaluations.

Material/Methods:

The Advanced Electron Density Phantom (Sun Nuclear, Melbourne, FL, USA) was utilized to simulate various tissue equivalent materials. Imaging was performed using a SOMATOM go.Open Pro scanner (Siemens Healthineers, Forchheim, Germany) following a standard dual-energy head protocol, employing a twin-spiral approach with tube settings of 80kV / Sn140kV. Regions of interest (ROIs) were positioned within the tissue-mimicking inserts to facilitate quantitative analysis of mean attenuation and noise levels (standard deviation). The impact of VMI level on image quality was investigated. Image quality was described by signal-to-noise ratio (SNR) und contrast-to-noise ratio (CNR).