Rubidium-82 generator yield and efficiency for PET perfusion imaging: Comparison of two clinical systems.
Ahmadi. Ali A; Klein. Ran R; Lewin. Howard C HC; Beanlands. Rob S B RSB; deKemp. Robert A RA
Key Findings
- CardioGen‑82 reported lower daily Rubidium‑82 activity than RUBY‑FILL, even though both had similar Strontium‑82 parent activity.
- The measurement method used for CardioGen‑82 under‑estimates true activity by about 24% compared to the integrated measurement used for RUBY‑FILL.
- When corrected to a common scale, CardioGen‑82’s production efficiency was about 7% lower than RUBY‑FILL’s over the study period.
Practical Outcomes
- For biohackers or independent researchers interested in using Rubidium‑82 PET imaging, the choice of generator matters: RUBY‑FILL may provide more reliable and higher yields. However, the findings do not offer any direct guidance on using the peptide cardiogen, so the study has little actionable relevance for peptide‑based health optimization.
Summary
This study compares two commercial Rubidium‑82 generators used for heart PET scans, showing that one system (RUBY‑FILL) consistently produces more usable radioactivity than the other (CardioGen‑82) because of differences in how the activity is measured and delivered.
Abstract
Strontium-82/Rubidium-82 (<sup>82</sup>Sr/<sup>82</sup>Rb) generators are used widely for positron emission tomography (PET) imaging of myocardial perfusion. In this study, the <sup>82</sup>Rb isotope yield and production efficiency of two FDA-approved <sup>82</sup>Sr/<sup>82</sup>Rb generators were compared. N = 515 sequential daily quality assurance (QA) reports from 9 CardioGen-82<sup>®</sup> and 9 RUBY-FILL<sup>®</sup> generators were reviewed over a period of 2 years. A series of test elutions was performed at different flow-rates on the RUBY-FILL<sup>®</sup> system to determine an empirical correction-factor used to convert CardioGen-82<sup>®</sup> daily QA values of <sup>82</sup>Rb activity (dose-calibrator 'maximum' of 50 mL elution at 50 mL·min<sup>-1</sup>) to RUBY-FILL<sup>®</sup> equivalent values (integrated 'total' of 35 mL elution at 20 mL·min<sup>-1</sup>). The generator yield (<sup>82</sup>Rb) and production efficiency (<sup>82</sup>Rb yield/<sup>82</sup>Sr parent activity) were measured and compared after this conversion to a common scale. At the start of clinical use, the system reported <sup>82</sup>Rb activity from daily QA was lower for CardioGen-82<sup>®</sup> vs RUBY-FILL<sup>®</sup> (2.3 ± 0.2 vs 3.0 ± 0.2 GBq, P < 0.001) despite having similar <sup>82</sup>Sr activity. Dose-calibrator 'maximum' (CardioGen-82<sup>®</sup>) values were found to under-estimate the integrated 'total' (RUBY-FILL<sup>®</sup>) activity by ~ 24% at 50 mL·min<sup>-1</sup>. When these data were used to convert the CardioGen-82 values to a common measurement scale (integrated total activity) the CardioGen-82<sup>®</sup> efficiency remained slightly lower than the RUBY-FILL<sup>®</sup> system on average (88 ± 4% vs 95 ± 4%, P < 0.001). The efficiency of <sup>82</sup>Rb production improved for both systems over the respective periods of clinical use. <sup>82</sup>Rb generator yield was significantly under-estimated using the CardioGen-82<sup>®</sup> vs RUBY-FILL<sup>®</sup> daily QA procedure. When generator yield was expressed as the integrated total activity for both systems, the estimated <sup>82</sup>Rb production efficiency of the CardioGen-82<sup>®</sup> system was ~ 7% lower than RUBY-FILL<sup>®</sup> over the full period of clinical use.
Study Information
pubmed
2020
2020-05-20T00:00:00.000Z
10.1007/s12350-020-02200-6
14
30