Preparation and labelling of red blood cells with [68Ga]Ga-oxine for PET/CT imaging of the human spleen

Abstract

Introduction: With the introduction of automated synthetization methods, the in-house production of several ⁶⁸Ga-based tracers became feasible in hospital laboratories. We describe a possible standard operating procedure (SOP) for [⁶⁸Ga]Ga-oxine-labeled heat-denaturated erythrocytes, which can be used for selective imaging in patients with splenic disorders.

Methods: Heat-denaturated erythrocytes were labeled with [⁶⁸Ga]Ga-oxine, which was produced from ⁶⁸Ga and 8-hydroxyquinoline on an automated synthesizer. The workflow was validated in a good manufacturing/good radiopharmaceutical practice (GMP/GRP) certified laboratory. A patient underwent [⁶⁸Ga]Ga-oxine-erythrocyte PET/CT for differentiation of an intrapancreatic mass.

Results: [⁶⁸Ga]Ga-oxine and [⁶⁸Ga]Ga-oxine-labeled erythrocytes could be synthesized reproducibly and reliably. The products met GMP quality standards. The tracer showed high accumulation in the intrapancreatic mass, consistent with an accessory spleen.

Conclusions: PET/CT imaging with [⁶⁸Ga]Ga-oxine-labeled, heat-denaturated erythrocytes can be a backup method for the differentiation of functioning splenic tissue from tumors. An SOP for the production of the tracer in a clinical setting could be established.

Keywords: Erythrocyte labeling; Gallium-68; Oxine; PET; Radiotracer; Spleen.