S2041
Physics - Image acquisition and processing
ESTRO 2026
clinical study, CNR was compared in organs at risks (OARs) from patient scans on both systems using identical reconstruction kernels and beam hardening corrections. Circular regions of interest (ROIs) were placed to measure CT numbers in OARs (CT numOAR) and muscles (CT nummuscle). Image noise was defined as the standard deviation in muscle (SDmuscle). Organ specific CNR was calculated as: CNR = (CT num OAR – CT nummuscle) / SD muscle Results: PCCT demonstrated significantly higher CNR for all simulated tissue contrasts (Fig 1). The maximum enhancement occurred at 40 keV VMIs, as expected, with CNR increases up to 376% for 8 mg/mL vs. 5 mg/mL contrast at 120 kVp compared to EID-CT. The preliminary clinical results matched the phantom findings, showing higher CNR for vascular organs on PCCT (Table 1). These improvements enable better differentiation of tissues with subtle contrast differences.
Conclusion: Phantom studies demonstrate PCCT's superior tissue conspicuity over EID-CT. Preliminary clinical data suggest these benefits extend to patient scans. This study sheds light on providing the oncologist, radiation therapist, medical physicist and medical dosimetrist the potential of PCCT in enhancing precise target and OAR delineation. Integrating PCCT into clinical workflows requires further validation in larger patient cohorts. References: McCollough, C. H., Rajendran, K., & Leng, S. (2023). Standardization and quantitative imaging with photon- counting detector CT. Investigative Radiology, 58(7), 451–458. Keywords: Photon-Counting Computed Tomography, Simulator Proffered Paper 443 Benchmarking synthetic computed tomography for radiotherapy from head to abdomen: SynthRAD2025 Grand Challenge report Viktor Rogowski 1,2 , Maarten Teerpstra 3,4 , Niklas Wahl 5,6 , Florian Kamp 7 , Erik van der Bijl 8 , Arthur Junior Galapon 9 , Christopher Kurz 10 , Guillaume Landry 10,11 , Adrian Thummerer 10 , Matteo Maspero 3,4 1 Radiation Physics, Department of Hematology, Oncology, and Radiation Physics, Skåne University Hospital, Lund, Sweden. 2 Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden. 3 Radiotherapy, Cancer and Image Divisio, University Medical Center Utrecht, Utrecht, Netherlands. 4 Computational Imaging Group for MR Diagnostics & Therapy, University Medical Center Utrecht, Utrecht, Netherlands. 5 Division of Medical Physics in Radiation Oncology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany. 6 Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany. 7 Department of Radiation Oncology and Cyberknife Center, University Hospital of Cologne, Cologne, Germany. 8 Department of Radiation Oncology, Radboud
Made with FlippingBook - Share PDF online