RT Journal Article SR Electronic T1 Multicenter Harmonization of 89Zr PET/CT Performance JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 264 OP 267 DO 10.2967/jnumed.113.130112 VO 55 IS 2 A1 Nikolaos E. Makris A1 Ronald Boellaard A1 Eric P. Visser A1 Johan R. de Jong A1 Bruno Vanderlinden A1 Roel Wierts A1 Berlinda J. van der Veen A1 Henri J.N.M. Greuter A1 Danielle J. Vugts A1 Guus A.M.S. van Dongen A1 Adriaan A. Lammertsma A1 Marc C. Huisman YR 2014 UL http://jnm.snmjournals.org/content/55/2/264.abstract AB This study investigated the feasibility of quantitative accuracy and harmonized image quality in 89Zr-PET/CT multicenter studies. Methods: Five PET/CT scanners from 3 vendors were included. 89Zr activity was measured in a central dose calibrator before delivery. Local activity assays were based on volume as well as on the local dose calibrator. Accuracy and image noise were determined from a cross calibration experiment. Image quality was assessed from recovery coefficients derived from different volume-of-interest (VOI) methods (VOIA50%, based on a 3-dimensional isocontour at 50% of the maximum voxel value with local background correction; VOIMax, based on the voxel with the highest uptake; and VOI3Dpeak, based on a spheric VOI of 1.2-cm diameter positioned so as to maximize the enclosed average). PET images were analyzed before and after postreconstruction smoothing, applied to match image noise. Results: PET/CT accuracy and image noise ranged from −3% to 10% and from 13% to 22%, respectively. VOI3Dpeak produced the most reproducible recovery coefficients. After calibration of the local dose calibrator to the central dose calibrator, differences between the local activity assays were within 6%. Conclusion: This study showed that quantitative accuracy and harmonized image quality can be reached in 89Zr PET/CT multicenter studies.