The aim of this study is to evaluate the diagnostic performance of Al18F-NOTA-LM3 PET/CT and compare it with 68Ga-DOTATATE PET/CT in patients with pheochromocytoma/paraganglioma (PPGL).

68Ga-based somatostatin receptor (SSTR) PET/CT has emerged as the cornerstone for staging and monitoring metastatic pheochromocytoma and paraganglioma (mPPGL), including its integral theranostic role in selecting patients for peptide receptor radionuclide therapy (PRRT). Compared to conventional 68Ga-DOTA-SSA analogs, 18F-labeled SSTR antagonists offer advantages including higher yield, superior image resolution, and longer half-life, potentially facilitating clinical workflow. Al18F-NOTA-LM3 is an SSTR2-specific antagonist developed as a PET tracer, with preliminary data supporting its safety, favorable biodistribution, and effective lesion targeting. This study aims to evaluate the diagnostic efficacy of Al18F-NOTA-LM3 PET/CT compared to 68Ga-DOTATATE PET/CT in a cohort of patients with PPGL.

Inclusion Criteria:

• Patients aged 18 to 80 years.
• Suspected or confirmed PPGL patients.

Exclusion Criteria:

• Combined with other types of tumors.
• Severe liver or renal dysfunction (ALT/AST≥5 ULN, GFR<30ml/min).
• Pregnant or breast-feeding women.
• Inability to perform PET/CT scans.