Multi-center performance evaluation of a prototype rubidium-82 elution system for low-dose PET myocardial perfusion imaging

Objectives Rubidium-82 (Rb-82) positron emission tomography (PET) myocardial perfusion imaging (MPI) is gaining more widespread use with its superior diagnostic accuracy compared to other alternatives and without the need for an onsite cyclotron. To ensure patient safety and optimal MPI, with the potential for added blood flow quantification, the injected activity must be accurate and precise without strontium-82 (Sr-82) breakthrough. We compared the performance of a prototype Rb-82 elution system at different PET imaging centers.

Methods The performance of a development prototype Rb-82 elution system, deployed at three imaging centers, was evaluated over a 1-year period. N=3170 patients underwent rest-stress MPI (6340 scans) using 30s constant-activity-rate infusions of 10 MBq/kg. Automated quality control (QC) measurements of Rb-82 yield and Sr-82 breakthrough detection limit values were recorded daily, from which precision was estimated. For patient scans, the requested vs. delivered activity (MBq) and elution time (s) were recorded to determine bias.

Results Daily QC values of Rb-82 yield and Sr-82 breakthrough detection limit had very good measurement precision combined over the three elution system units: ±0.1%. Overall, patient eluted activity values were highly accurate, with a very small positive bias of 0.7±2.2%; 99% of cases had <5% bias in the delivered vs. requested activity. Patient elution times also had a small bias of 1.0±1.5s, with 96% of the delivered elution times within 6s of the standard 30s time requested. No significant differences in any of the above metrics were observed between elution system units or imaging centers.

Conclusions The prototype Rb-82 elution system is accurate and precise, with consistent performance between different units and imaging centers. RESEARCH SUPPORT: Clinical trial #NCT02117284 supported by Jubilant DraxImage Inc.