Title:Physiological Animal Imaging with 68Ga-Citrate
Volume: 14
Issue: 1
Author(s): Ayşe Uğur and Aziz Gültekin*
Affiliation:
- Pamukkale University, Medical Faculty, Department of Nuclear Medicine, 20160, Denizli,Turkey
Keywords:
Gallium, 68Gallium-citrate, PET/CT, 68Ga infection and inflammation imaging agents, radiolabelling, quality control,
physiological distribution of 68Ga-citrate in rabbit.
Abstract:
Background: Gallium-68 is an ideal research and hospital-based PET radioisotope. The
uptake mechanism of Gallium citrate is a combination of specific and non-specific processes, for
example, vasodilatation, increased vascular permeability, plasma transferrin binding and lactoferrin
and siderophores.
Objective: In this study, by applying the 68Ge/68Ga generator product, a simple technique for the
synthesis and quality control of 68Ga-citrate was introduced and was followed by preliminary animal
studies.
Methods: The synthesis of 68Ga-citrate was performed with a cationic method using the Scintomics
automated synthesis system (Scintomics GmbH GRP module 4V). Since the standard procedure
for quality control (QC) was not available, the definition of chemical and radiochemical purity of
68Ga-citrate was carried out according to the ICH Q2(R1) guideline. The standard QC tests were
analysed with Scintomics 8100 radio-HPLC system equipped with a radioactivity detector. In this
study, a New Zealand rabbit weighing 2520 g was used for PET/CT images.
Results: 68Ga-citrate synthesis was performed by a cationic method without using organic solvents.
The labelling efficiency was found to be >98%. The HPLC method used to assess the radiochemical
purity of 68Ga -citrate was validated as rapid, accurate and reproducible enough to apply it to patients
safely. The physiological distribution of 68Ga-citrate was investigated in a healthy rabbit. The
blood pool, liver, spleen, kidneys and growth plates were the most common sites of 68Ga-citrate involvement.
