68Ga-pentixafor PET/CT Is a Supplementary Method for Primary Aldosteronism Subtyping Compared with Adrenal Vein Sampling

Abstract Purpose To investigate the diagnostic efficacy of 68 Ga-pentixafor positron emission tomography/computed tomography (PET/CT) in primary aldosteronism (PA) subtyping and lateralization of aldosterone secretion in PA patients. Procedures 37 patients who were diagnosed with PA, were prospectively enrolled in the study, and underwent adrenal vein sampling (AVS) after 68 Ga-pentixafor PET/CT was conducted. Lateralization index (LI), defined as aldosterone/cortisol ratio in the dominant side to the contralateral adrenal vein when bilateral adrenal vein catheterization succeeded, and the aldosterone/cortisol ratio in the left adrenal vein to IVC (LAV/IVC) when the catheterization of right adrenal vein failed, were applied to determine lateralization side. Statistical analysis was performed using SPSS 21.0. Results The female proportion of all patients with PA was 32.4% (12/37), and the mean age was 51.3 ± 10.9 years. Patients with bilateral adrenal mass accounted for 54.1% (20/37), and 10 of them (27.0%) had adrenal hyperplasia or adrenal nodules ≤ 1.0 cm. In all 37 patients, the sensitivity, specificity and accuracy of 68 Ga-pentixafor PET/CT in distinguishing lateralization by visualization were 89.3%, 77.8% and 86.5%, respectively. The area under the ROC curve for detecting positive lateralization based on the value of 68 Ga-pentixafor SUV max was 0.750 (95%CI 0.578–0.922, p = 0.026). The optimum SUV max cut-off value was 6.86, with the sensitivity of 78.6%, specificity of 66.7%, and accuracy of 78.4%. Defining SUV ratio as SUV max /SUV of contralateral adrenal gland, the area under the ROC curve for identifying lateralization based on the SUV ratio was 0.710 (95%CI 0.500–0.921, p = 0.061). The optimum SUV ratio cut-off was 2.40, with the sensitivity of 60.7%, specificity of 88.9%, and accuracy of 67.6%. The consistency of 68 Ga-pentixafor PET/CT with AVS was of no significant difference between patients with bilateral adrenal lesions (80.0%, 16/20) and unilateral lesion (94.1%, 16/17; p = 0.737), and no significance was revealed in the consistency between patients with adrenal hyperplasia or adrenal lesion of diameter ≤ 1 cm (81.8%, 9/11) and those with adrenal lesions > 1 cm (88.5%, 23/26; p = 0.884). Conclusions 68 Ga-pentixafor PET/CT showed at least 80% consistency for the lateralization in patients with PA compared with AVS, even in those presented with bilateral adrenal hyperplasia. Visual analysis exhibited better diagnostic efficacy compared with SUV max or SUV max /SUV of the contralateral adrenal gland.( ChiCTR2300073049. Registered 30 June 2023. Retrospectively registered)