68Ga-pentixafor PET/CT in the localization diagnosis of primary aldosteronism concurrent subclinical cushing's syndrsome: two case reports

Purpose Adrenal venous sampling (AVS) is recommended for subtyping primary aldosteronism (PA). However, in cases of PA, concurrent subclinical Cushing's syndrome (SCS) has the potential to confound AVS results. Pentixafor, a CXC chemokine receptor type 4-specific ligand, has been reported as a promising marker to evaluate functional nature of adrenal adenomas. This study aims to investigate the clinical value of Gallium-68 Pentixafor Positron Emission Tomography-Computed Tomography (Ga-68-Pentixafor PET/CT) in the localization diagnosis of patients with PA plus SCS. Methods Two patients with a confirmed diagnosis of PA plus SCS underwent AVS and Ga-68-Pentixafor PET/CT. Results AVS results revealed no lateralization for both patients while Ga-68-Pentixafor PET/CT showed a unilateral adrenal nodule with increased uptake of Ga-68-Pentixafor. Unilateral adrenalectomy was performed based on the results of Ga-68-Pentixafor PET/CT. Subsequently, complete biochemical remission of autonomous aldosterone and cortisol secretion were achieved in both cases. Conclusions Ga-68-Pentixafor PET/CT shows promising potential for the localization of aldosterone and cortisol co-secreting adrenal adenoma in patients with PA plus SCS.