Résumé
Objectives: To develop and assess alternative radiolabeling strategies for SOMAKIT-TOC® using gallium-68, with the aim of improving cost-efficiency by increasing the number of examinations per cold kit while maintaining radiochemical quality suitable for clinical use.Materials and Methods: Four protocols were evaluated using triplicate test radiolabelings: (1) reference method using a single generator and a full kit; (2) dual-generator elution into a full kit; (3) single-generator elution into two sequentially radiolabeled aliquots from one kit; and (4) dual-generator elution into two aliquots. Radiochemical purity (RCP) was assessed by radio-TLC and radio-HPLC, and radiochemical stability was monitored over 4 hours. Additional quality controls included pH, sterility, and peptide integrity in aliquot solution. Procedures 1 and 3 were further assessed in clinical routine.Results: All protocols yielded radiopharmaceuticals with mean RCP values above 95% by radio-TLC. Procedure 2 significantly increased final activity compared to Procedure 1. Procedure 3 enabled doubling the number of examinations per kit with comparable RCP to the reference. Procedure 4 showed greater variability. Radiolabeled products remained stable over 4 hours by radio-TLC, though radio-HPLC revealed a gradual decrease in purity. In clinical use, Procedure 3 allowed 94 preparations meeting diagnostic needs, though 33% had RCP between 80% and 95%.Conclusion: Aliquoting a single cold kit for dual radiolabeling with one generator is feasible and cost-effective, though associated with greater RCP variability. Dual-generator strategies yield higher activity but may further compromise RCP. Further optimization is required to improve robustness of off-label protocols while preserving the highest product quality.