This study is a randomized controlled trial to assess the clinical utility of gallium-68 pentixafor PET/CT in the management of primary aldosteronism (PA). We aim to evaluate whether the addition of 68Ga-pentixafor PET/CT to standard adrenal venous sampling (AVS) improves surgical outcomes in patients with unilateral PA.
Primary aldosteronism (PA) is a common cause of secondary hypertension. Accurate subtype classification (unilateral vs. bilateral) is essential to determine whether patients should receive adrenalectomy or medical therapy. AVS is the current gold standard but has limitations, including its invasiveness, technical difficulty, and risk of failure. Recently, non-invasive imaging techniques such as 68Ga-pentixafor PET/CT and 11C-metomidate PET/CT have emerged as promising alternatives for subtype classification. These PET-based methods target molecular markers (e.g., CXCR4, CYP11B2) and show moderate to high concordance rates with AVS (66.7%-90% for pentixafor). However, there is insufficient prospective evidence on whether these modalities can improve treatment outcomes. This randomized controlled trial aims to assess whether adding 68Ga-pentixafor PET/CT to standard AVS improves surgical outcomes in patients with unilateral PA. Participants are randomized 1:1 to undergo either AVS alone or AVS plus 68Ga-pentixafor PET/CT. Additionally, 11C-metomidate PET/CT is performed in the intervention arm purely for research purposes and will not influence treatment decisions. By improving the precision of subtype classification, this study aims to improve patient selection for adrenalectomy, and ultimately enhance clinical outcomes in primary aldosteronism.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
90
Diagnostic PET/CT imaging using gallium-68 labeled pentixafor to assess adrenal CXCR4 expression in patients with primary aldosteronism. The imaging is performed prior to treatment allocation and used to assist lateralization of aldosterone production when combined with adrenal venous sampling (AVS).
Samsung Medical Center
Seoul, Gangnam-gu, South Korea
RECRUITINGSeoul National University Hospital
Seoul, Jongno-gu, South Korea
RECRUITINGBiochemical remission rate after adrenalectomy (surgery group only)
Number of participants achieving biochemical success as defined by PASO criteria will be assessed. Biochemical success is defined as normalization or improvement in aldosterone-to-renin ratio (ARR) and correction of hypokalemia without potassium supplementation in patients with unilateral primary aldosteronism who underwent adrenalectomy.
Time frame: 6 months after adrenalectomy
Clinical remission rate after adrenalectomy or initiation of medical therapy
Number of participants achieving clinical success according to PASO (surgical group) or PAMO (medical group) criteria will be assessed. Clinical success includes normalization of blood pressure and reduction in number or dose of antihypertensive medications after surgery or medical therapy.
Time frame: 6 months after treatment (surgery or medication)
Agreement rate between PET/CT imaging and adrenal venous sampling (AVS)
Agreement rate between 68Ga-pentixafor PET/CT (+11C-metomidate PET/CT for subgroup) and adrenal venous sampling (AVS) will be assessed. Diagnostic agreement will be evaluated based on lateralization patterns from PET/CT and AVS using predefined laterality thresholds.
Time frame: 6 months after treatment (surgery or medication)
Concordance between AVS-based lateralization and immunohistochemical (IHC) expression of CXCR4 and CYP11B2
Concordance between AVS-based lateralization and immunohistochemical (IHC) expression of CXCR4 and CYP11B2 will be assessed. IHC positivity for CXCR4 and CYP11B2 will be recorded as presence or absence in each adrenal lesion. Concordance will be evaluated by comparing lateralization results from AVS with the presence or absence of expression.
Time frame: 6 months after treatment
Concordance between PET/CT-based lateralization and immunohistochemical (IHC) expression of CXCR4 and CYP11B2
Concordance between PET/CT-based lateralization and immunohistochemical (IHC) expression of CXCR4 and CYP11B2 will be assessed. IHC positivity for CXCR4 and CYP11B2 will be recorded as presence or absence in each adrenal lesion. Concordance will be evaluated by comparing PET/CT-based lateralization with the presence or absence of expression in the corresponding adrenal tissue.
Time frame: 6 months after treatment
Correlation between the AVS-derived lateralization index and the SUVmax ratio on PET/CT
The correlation between the AVS-derived lateralization index and the SUVmax ratio on PET/CT will be evaluated. SUVmax ratios will be quantitatively compared with AVS findings, including the lateralization index, as well as tumor size and the side of dominant hormone secretion
Time frame: 6 months after treatment
Change in plasma aldosterone concentration/aldosterone-to-renin ratio (ARR)
Change from baseline in plasma aldosterone concentration and ARR will be assessed. Plasma aldosterone and ARR will be measured at baseline and 6 months post-treatment to evaluate endocrine improvement.
Time frame: Baseline and 6 months after treatment
Rate of blood pressure normalization
Proportion of participants with blood pressure below 140/90 mmHg without escalation of antihypertensive medications will be assessed. Participants achieving target blood pressure without medication escalation will be recorded.
Time frame: 6 months after treatment
Change in antihypertensive medication use
Change in number and dose of antihypertensive medications from baseline will be assessed. Total daily defined dose and number of medications will be compared between baseline and 6 months after treatment.
Time frame: Baseline and 6 months after treatment
Change in serum potassium level
Change in serum potassium concentration from baseline will be assessed. Serum potassium levels at baseline and 6 months post-treatment will be compared to evaluate metabolic improvement.
Time frame: Baseline and 6 months after treatment
Frequency and percentage of histologic subtype classification in resected adrenal tissue
Frequency and percentage of histologic subtype classification in resected adrenal tissue will be assessed. Resected adrenal tissues will be classified according to histologic subtypes, and the distribution of each subtype will be recorded.
Time frame: 3 months after adrenalectomy
Size of resected adrenal tumors
Size of resected adrenal tumors will be assessed. Tumor diameter will be measured in centimeters based on pathology reports.
Time frame: 3 months after adrenalectomy
Correlation between somatic mutations and PET/CT SUVmax ratio
The correlation between somatic mutations and PET/CT SUVmax ratios of adrenal tumors will be evaluated. Mutation profiles (e.g., KCNJ5, CACNA1D, etc.) will be analyzed in relation to SUVmax measurements obtained from PET/CT imaging.
Time frame: 3 months after adrenalecotmy
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