DOI: 10.1007/s00259-017-3694-4Pages: 1-4

Clinical feasibility of 90Y digital PET/CT for imaging microsphere biodistribution following radioembolization

1. The Ohio State University Wexner Medical Center, Wright Center of Innovation in Biomedical Imaging, Department of Radiology

2. The Ohio State University Wexner Medical Center, Department of Radiation Oncology

Correspondence to:
Michael V. Knopp
Tel: +1-614-293-9998




The purpose of this study was to evaluate the clinical feasibility of next generation solid-state digital photon counting PET/CT (dPET/CT) technology and imaging findings in patients following 90Y microsphere radioembolization in comparison with standard of care (SOC) bremsstrahlung SPECT/CT (bSPECT/CT).


Five patients underwent SOC 90Y bremsstrahlung imaging immediately following routine radioembolization with 3.5 ± 1.7 GBq of 90Y-labeled glass microspheres. All patients also underwent dPET/CT imaging at 29 ± 11 h following radioembolization. Matched pairs comparison was used to compare image quality, image contrast and 90Y biodistribution between dPET/CT and bSPECT/CT images. Volumetric assessments of 90Y activity using different isocontour thresholds on dPET/CT and bSPECT/CT images were also compared.


Digital PET/CT consistently provided better visual image quality and 90Y-to-background image contrast while depicting 90Y biodistribution than bSPECT/CT. Isocontour volumetric assessment using a 1% threshold precisely outlined 90Y activity and the treatment volume on dPET/CT images, whereas a more restrictive 20% threshold on bSPECT/CT images was needed to obtain comparable treatment volumes. The use of a less restrictive 10% threshold isocontour on bSPECT/CT images grossly overestimated the treatment volume when compared with the 1% threshold on dPET/CT images.


Digital PET/CT is clinically feasible for the assessment of 90Y microsphere biodistribution following radioembolization, and provides better visual image quality and image contrast than routine bSPECT/CT with comparable acquisition times. With further optimization and clinical validation, dPET technology may allow faster and more accurate imaging-based assessment of 90Y microsphere biodistribution.

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  • Accepted: Mar 27, 2017
  • Online: Apr 12, 2017

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