Gallium-68 pentixa PET-CT promising noninvasive subtyping method for patients with primary aldosteronism

A new study by Jinbo Hu and team showed that Gallium-68 pentixa for positron emission tomography-computed tomography (PET-CT) has high diagnostic precision for distinguishing between unilateral primary aldosteronism (UPA) and bilateral primary aldosteronism (BPA). The findings of this study were published in the Journal of American Medical Association. 

The preferred approach for subtyping primary aldosteronism (PA) as unilateral PA (UPA) or bilateral PA (BPA) is adrenal vein sampling (AVS). Each subtype requires a distinct course of therapy, such as adrenalectomy for UPA and medication for BPA. Nevertheless, AVS is invasive and technically challenging, and it is currently very difficult to characterize PA noninvasively. Thus, using AVS as a reference standard, this study was done to assess the efficacy of gallium-68 pentixafor positron emission tomography-computed tomography in subtyping PA.

Patients with PA were the subjects of this diagnostic investigation, which was carried out at a tertiary hospital in China. Enrollment began in November 2021, and follow-up was completed in May 2022. The recruitment of patients for gallium-68 pentixafor PET-CT and AVS. To determine the lateralization index of SUVmax, the maximum standardized uptake value (SUVmax) of each adrenal gland during PET-CT was determined. In order to evaluate the lateralization index based on SUVmax's accuracy in subtyping PA, the following metrics were used: area under the receiver operating characteristic curve (AUROC), specificity, and sensitivity.

The key findings of this study were:

43 patients with UPA and 57 with BPA were among the 100 PA patients who completed the research. 

SUVmax of the adrenal glands at 10 minutes during PET-CT was strongly linked with the aldosterone-cortisol ratio in the adrenal veins. 

The AUROC was 0.90 when using a lateralization index based on SUVmax at 10 minutes to identify UPA. 

A cutoff value of 1.65 for the lateralization index based on SUVmax at 10 minutes resulted in a sensitivity and specificity of 1.00. 90 patients (90.0%) had diagnostic concordance between PET-CT and AVS, as opposed to 54 patients (54.0%) between standard CT and AVS.

Gallium-68 pentixafor PET-CT may offer a unique and promising method for PA subtyping, however it deserves additional study in a wider population given the global need for safe, accurate, and noninvasive alternatives to AVS.

Reference:

Hu, J., Xu, T., Shen, H., Song, Y., Yang, J., Zhang, A., Ding, H., Xing, N., Li, Z., Du, Z., He, W., Sun, Y., Cai, J., Li, Q., … Chen, Y. (2023). Accuracy of Gallium-68 Pentixa for Positron Emission Tomography–Computed Tomography for Subtyping Diagnosis of Primary Aldosteronism. In JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2022.55609