68Ga-exendin-4 PET/CT for the localization of insulinomas / 中华核医学与分子影像杂志

ABSTRACT

Objective To determine whether glucagon-like peptide-1 (GLP-1) receptor PET/CT with 68Ga-exendin-4 is accurate in localizing insulinomas,by comparing with conventional imaging techniques.Methods In this prospective cohort study,patients with biochemically proven endogenous hyperinsulinemic hypoglycemia from March 2014 to November 2016 were recruited consecutively.68Ga-exendiri-4 PET/CT,CT,MRI,endoscopic ultrasound (EUS),and SSTR imaging were performed before elective surgery.Surgical pathology results were considered as the gold standard.Sensitivity based on patient-analysis and positive predictive value (PPV) based on lesion-analysis were calculated and compared using x2 test and generalized score test.Results A total of 109 patients were recruited (47 males,62 females;average age (45.1±14.8) years),and 96 of them with insulinomas proved pathologically were included in the main assessment.Thirteen patients with positive 68Ga-exendin-4 PET/CT findings did not undergo surgical intervention.Based on patient-analysis,the sensitivities of 68Ga-exendin-4 PET/CT,CT,MRI,EUS and SSTR imaging for detecting insulinomas were 98.96％ (95/96),81.25％ (78/96),79.41％ (54/68),81.40％ (35/43) and 21.84％ (19/87),respectively.Based on lesion-analysis,the PPV of the above 5 methods were 100％ (102/102),97.56％ (80/82),95.16％ (59/62),83.72％ (36/43) and 90.48％ (19/21),respectively.68 Gaexendin-4 PET/CT showed the highest diagnostic sensitivity than others (all P＜0.01) and higher PPV than MRI,EUS and SSTR imaging (all P＜0.05).Conclusion 68Ga-exendin-4 PET/CT is a highly sensitive imaging technique for detection of insulinoma.