Automated Gallium-68 dotate production: An 800 patient experience

Abstract

Background: Ga-68 is an ideal research and hospital-based PET radioisotope. The main form of Ga-68 radiopharmaceutical that is being synthesised in-house is currently Ga-68 conjugated with DOTA-based derivatives. The use of automated synthesis systems is on the increase. These systems have obvious advantages over the manual methods which have resulted in their increasing installation and use in hospital-based radiopharmacies. Here we report on our three year, 500 syntheses experience with an automated synthesis system for Ga-68 DOTATATE. Aims: Our aim is to report on the experience with the Eckert & Ziegler Eurotope's Modular-Lab PharmTracer automated synthesis system used for routine Ga-68 DOTATATE production. Methods: The automated synthesis system we use is divided into three parts: servomotor modules, single use synthesis cassettes and a computerised system that runs the modules.An audit trail is produced as required for GMP production. Generator performance (Germanium breakthrough) is determined on a weekly basis. Production yields for each synthesis are calculated and quality of the final product is assessed after each synthesis by ITLC-SG and HPLC. Results: A total of 500 Ga-68 DOTATATE syntheses (>800 patient doses) were performed between March 2011 and February 2014. The average generator yields for 2011, 2012 and 2013 were 81.3 +/- 0.2%, 76.7 +/- 0.4% and 75.0 +/- 0.3% respectively.These exceeded the manufacturers' expected value of 70%. Ga-68 DOTATATE yields for 2011, 2012 and 2013 were 81.8 +/- 0.4%, 82.2 +/- 0.4% and 87.9 +/- 0.4% respectively. Germanium breakthrough averaged 8.6 x 10^-6% of total activity. Radiochemical purity >98%. Cassette system failures led to patient scans being rescheduled on eight occasions only. Conclusion: In our experience the automated synthesis system performs reliably with a relatively low incident of failures. Our system had a consistent and reliable Ga-68 DOTATATE output with high labelling efficiency. The system is GMP-compliant and has low maintenance and acceptable running costs.