68Ga-Pentixafor Positron Emission Tomography/Computed Tomography in Primary Aldosteronism: Preliminary Analysis on Contrast-Enhanced Computed Tomography Concordance and Positron Emission Tomography/Computed Tomography Avidity Patterns.

68Ga-Pentixafor positron emission tomography/computed tomography has shown potential in primary aldosteronism subtyping, but analysis of its diagnostic accuracy based on contrast-enhanced computed tomography concordance and positron emission tomography/computed tomography avidity patterns is lacking. The objective of this study was to evaluate the diagnostic accuracy of 68Ga-Pentixafor positron emission tomography/computed tomography for subtyping primary aldosteronism and to assess its performance based on concordance with contrast-enhanced computed tomography and positron emission tomography/computed tomography avidity patterns. Clinical, biochemical, radiological, functional imaging, treatment, histopathological, and follow-up details of 30 patients with primary aldosteronism who underwent positron emission tomography/computed tomography over 2 years at a tertiary center in India were retrospectively analyzed. Diagnostic accuracy of positron emission tomography/computed tomography for primary aldosteronism subtyping was evaluated in the whole cohort and in subgroups based on contrast-enhanced computed tomography-positron emission tomography/computed tomography concordance and positron emission tomography/computed tomography avidity patterns. Out of the 30 patients, final subtype classification was achieved in 15 (9 unilateral and 6 bilateral) based on surgical outcomes and/or adrenal venous sampling. Positron emission tomography/computed tomography correctly subtyped 14/15 (93.3%) patients. Contrast-enhanced computed tomography and positron emission tomography/computed tomography concordance was seen in 10 patients, and positron emission tomography/computed tomography accuracy was 100% (10/10) in this subgroup. Contrast-enhanced computed tomography and positron emission tomography/computed tomography discordance (contrast-enhanced computed tomography bilateral and positron emission tomography/computed tomography unilateral) was seen in five patients, and positron emission tomography/computed tomography accuracy in this subgroup was 80% (4/5). Positron emission tomography/computed tomography avidity patterns in the 15 patients having final subtype classification were unilateral avid (n=10), bilateral avid (n=2), and bilateral nonavid (n=3). Diagnostic accuracy of positron emission tomography/computed tomography was 90% (9/10) in patients with unilateral avidity, and 100% in those with bilateral avidity or nonavidity. Preliminary analysis suggests that positron emission tomography/computed tomography demonstrates higher accuracy in certain subgroups, potentially guiding the triage for adrenal venous sampling.