PETAL Trial: Impact of Gallium-68 Pentixafor PET-CT on Surgical Outcomes in Primary Aldosteronism

A Randomized Controlled Trial to Evaluate the Effect of Gallium-68 Pentixafor PET-CT on Surgical Outcomes in Patients With Primary Aldosteronism (The PETAL Trial)

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.

Inclusion Criteria:

• Age ≥19 years
• Diagnosed with PA per 2016 Endocrine Society guidelines
• Underwent adrenal CT
• Signed informed consent

Exclusion Criteria:

• Women who are pregnant, breastfeeding, or may become pregnant
• Individuals who refuse to undergo surgery
• Individuals for whom 68Ga-Pentixafor PET/CT, 11C-Metomidate PET/CT, or adrenal venous sampling (AVS) is not feasible or is refused due to underlying conditions
• Individuals who refuse or experience adverse effects from dexamethasone premedication required for 11C-Metomidate PET/CT
• Individuals with a history of abdominal open surgery or retroperitoneal surgery on the same side as the planned adrenalectomy
• Any individual deemed unsuitable for the study at the discretion of the investigator