Decreased 68Ga-NOTA-exendin-4 renal uptake in patients pretreated with Gelofusine infusion: a randomized controlled study

Abstract

Abstract Objective: Glucagon-like peptide-1 receptor imaging, using 68Ga-NOTA-exendin-4 is recently established for detecting insulinomas. Owing to the highly radioactive kidneys in 68Ga-NOTA-exendin-4 PET/CT, we aimed to determine the effectiveness of Gelofusine in reducing renal uptake of 68Ga-NOTA-exendin-4. Methods: In our randomized controlled study, patients presenting for 68Ga-NOTA-exendin-4 PET/CT who were ≥18 years and with normal renal function were enrolled, and then randomized into intervention group and control group. Patients in intervention group (group 1) underwent infusion of 500 mL Gelofusine prior to PET/CT procedures: patients injected with 68Ga-NOTA-exendin-4 (group 1a) immediately after 500 mL Gelofusine infusion was completed; (group 1b) at the time point that 250 to 300 mL Gelofusine infusion was completed; (group 1c) 30 minutes after completion of 500 mL Gelofusine infusion. The control group (group 2) received 500 mL 5% glucose saline instead. PET/CT was then performed, and SUVs of the kidneys and insulinomas were measured. Results: A total of 28 patients were recruited. There were 7 patients (14 kidneys) in each subgroup. The age, body weight, BMI, renal function, injected 68Ga-exendin-4 activity, and interval between injection of the tracer and PET/CT scan were not significantly different among the groups (P > .05). The average and maximum SUVs in the kidneys were significantly reduced in patients of intervention group compared with the control subjects (P < .0001), and the renal uptake could be decreased by 57% with Gelofusine pretreatment. No significant difference in the renal radioactivity was found among group 1a, 1b, and 1c (P = .071). The uptake of insulinomas was not significantly different between the intervention and control groups. Conclusion: Renal uptake of 68Ga-exendin-4 can be effectively reduced by pretreatment with Gelofusine.