To evaluate the value of 68Ga-Pentixafor PET/CT in the diagnosis of primary aldosteronism subtype

This is a prospective study. We will enroll 100 patients with definite diagnosis of PA using adrenal venous sampling(AVS) as the gold standard for subtype to evaluate the value of 68Ga-pentixaforPET/CT in the diagnosis of PA.

Inclusion Criteria:

1. PA diagnosis confirmed by at least one confirmatory test
2. willingness to undergo AVS and surgery
3. informed consent to participate in the study.

Exclusion Criteria:

1. PA patients who met guideline criteria for bypassing AVS [i.e. younger than 35 years old, with typical APA characteristics (plasma aldosterone >300pg/ml, plasma renin < 2·5mIU/l, serum potassium <3·5mmol/l, CT indicated unilateral 1cm low-density adenoma);
2. failed adrenal vein cannulation during AVS;
3. Subtyping diagnosis was inconclusive based on AVS results (e.g. aldosterone/cortisol ratio in bilateral adrenal veins lower than the peripheral vein, or missing data);
4. pregnant or lactating women;
5. patients with a history of uncontrolled malignant tumor;
6. concurrent Cushing's syndrome [including mild autonomous cortisol secretion: cortisol after 1mg dexamethasone suppression test (DST)>138 nmol/l or cortisol after 2mg DST >50 nmol/l or cortisol after 1mg DST 50-138 nmol/l plus adrenocorticotrophic hormone (ACTH)<10pg/ml;
7. diagnosis of familial hyperaldosteronism;
8. imaging characteristics suggestive of pheochromocytoma or adrenal cortical carcinoma;
9. unsuitable for surgery, such as heart failure with New York Heart Association (NYHA) class III or IV, severe anemia (Hemoglobin<60g/L), stroke or acute coronary syndrome within 3 months, severe ascites and cirrhosis, estimated glomerulus filtration rate<30ml/min/m;
10. alcohol or drug abuse and mental disorders.](streamdown:incomplete-link)

Power Analysis and Sample Size software 11 (PASS 11) was used to calculate the sample size. A sample of 40 from the positive group (i.e. UPA group) and 60 from the negative group (i.e. BPA group) achieves 84% power to detect a difference of 0·15 between the area under the receiver-operator characteristics curve (AUC) under the null hypothesis of 0·70 and an AUC under the alternative hypothesis of 0·85 using a two-sided z-test at a significance level of 0·05.