Validation of (68)Ge/(68)Ga generator processing by chemical purification for routine clinical application of (68)Ga-DOTATOC.

Introduction: Imaging of somatostatin receptor expressing tumours has been greatly enhanced by the use of (68)Ga-DOTATOC and PET/CT.

Methods: In this work, a purification method for the (68)Ge/(68)Ga generator eluate and a method to produce (68)Ga-DOTATOC suitable for clinical use were evaluated. The generator eluate was purified and concentrated on a cation-exchange cartridge in HCl/acetone media. The efficacy of this procedure in eliminating metal impurities from the (68)Ga solution was investigated by ICP-MS. The radiotracer quality was evaluated by radio-TLC, GC and gamma-ray spectrometry.

Results: (68)Ga-DOTATOC preparations (n=33) were carried out with a mean synthesis yield of 59.3+/-2.8% (not corrected for decay) and a batch activity ranging from 555 to 296 MBq. The radiochemical and radionuclidic purity were >98% and 99.9999%, respectively. With this purification process, >95% of the Fe(III), Zn(II) and Mn(II) were eliminated from the solution.

Conclusions: (68)Ga-DOTATOC produced with this method can be efficiently used in nuclear medicine departments for PET evaluations.