68Ga-Pentixafor PET/CT for Subtyping Diagnosis of Primary Aldosteronism: A Prospective, Diagnostic Accuracy Study

Purpose: Adrenal vein sampling (AVS) is the recommended procedure for subtyping primary aldosteronism (PA) as unilateral PA (UPA) or bilateral PA (BPA) which needs adrenalectomy and medication treatment, respectively. However, AVS is invasive and technically difficult. How to subtype PA non-invasively is currently a great challenge. We aimed to prospectively evaluate the accuracy of 68Ga-Pentixafor positron emission tomography/computed tomography (PET/CT) in subtyping PA, using AVS as a reference standard.Methods: Patients diagnosed with PA were recruited to undergo AVS and 68Ga-Pentixafor PET/CT. Maximum standardized uptake value (SUVmax) of each adrenal during the PET/CT was measured to calculate the lateralization index (LI) of SUVmax. Area under the receiver operating characteristic curve (AUC), specificity and sensitivity were used to analyze the accuracy of LI based on SUVmax for subtyping PA.Results: One hundred PA patients completed the study, including 43 UPA and 57 BPA. SUVmax of adrenals at 10min during the PET/CT positively correlated with aldosterone concentration (r=0.27, P=0.0001) as well as aldosterone-cortisol ratio (r=0.38, PConclusions: 68Ga-Pentixafor PET/CT is a promising subtyping method for PA with high diagnostic accuracy. For a large proportion of PA patients, 68Ga-Pentixafor PET/CT could be used to avoid invasive AVS.Trial registration number：ClinicalTrials.gov: NCT 05131061. Registered 10 November 2021.