DOI: 10.1186/s40658-018-0206-yPages: 1-18

Multi institutional quantitative phantom study of yttrium-90 PET in PET/MRI: the MR-QUEST study

1. Washington University School of Medicine, Department of Radiation Oncology

2. Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute

3. City College of New York, Department of Biomedical Engineering

4. Siemens Medical Solutions USA, Inc., Siemens Healthineers

5. Siemens Healthineers, Molecular Imaging

6. NTNU, Norwegian University of Science and Technology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences

7. Icahn School of Medicine at Mt. Sinai, Department of Radiology

8. National University of Singapore Clinical Imaging Research Centre, Agency for Science Technology and Research

9. Cleveland Clinic, Department of Nuclear Medicine

10. NYU Medical Center

11. TU München, Klinik und Poliklinik für Nuklearmedizin

12. Charité—Universitätsmedizin Berlin, Department of Nuclear Medicine

13. Siemens Healthcare GmbH

14. Sirtex Medical Ltd

15. ABX-CRO Advanced Pharmaceutical Services

16. Washington University School of Medicine, Mallinckrodt Institute of Radiology

Correspondence to:
Parag J. Parikh




Yttrium-90 (90Y) radioembolization involves the intra-arterial delivery of radioactive microspheres to treat hepatic malignancies. Though this therapy involves careful pre-treatment planning and imaging, little is known about the precise location of the microspheres once they are administered. Recently, there has been growing interest post-radioembolization imaging using positron-emission tomography (PET) for quantitative dosimetry and identifying lesions that may benefit from additional salvage therapy. In this study, we aim to measure the inter-center variability of 90Y PET measurements as measured on PET/MRI in preparation for a multi-institutional prospective phase I/II clinical trial.

Eight institutions participated in this study and followed a standardized phantom filling and imaging protocol. The NEMA NU2-2012 body phantom was filled with 3 GBq of 90Y chloride solution. The phantom was imaged for 30 min in listmode on a Siemens Biograph mMR non-TOF PET/MRI scanner at five time points across 10 days (0.3–3.0 GBq). Raw PET data were sent to a central site for image reconstruction and data analysis. Images were reconstructed with optimal parameters determined from a previous study. Volumes of interest (VOIs) matching the known sphere diameters were drawn on the vendor-provided attenuation map and propagated to the PET images. Recovery coefficients (RCs) and coefficient of variation of the RCs (COV) were calculated from these VOIs for each sphere size and activity level.


Mean RCs ranged from 14.5 to 75.4%, with the lowest mean RC coming from the smallest sphere (10 mm) on the last day of imaging (0.16 MBq/ml) and the highest mean RC coming from the largest sphere (37 mm) on the first day of imaging (2.16 MBq/ml). The smaller spheres tended to exhibit higher COVs. In contrast, the larger spheres tended to exhibit lower COVs. COVs from the 37 mm sphere were < 25.3% in all scans. For scans with ≥ 0.60 MBq/ml, COVs were ≤ 25% in spheres ≥ 22 mm. However, for all other spheres sizes and activity levels, COVs were usually > 25%.


Post-radioembolization dosimetry of lesions or other VOIs ≥ 22 mm in diameter can be consistently obtained (< 25% variability) at a multi-institutional level using PET/MRI for any clinically significant activity for 90Y radioembolization.

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  • Accepted: Feb 16, 2018
  • Online: Apr 4, 2018

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