Performances of Functional and Anatomic Imaging Modalities in Succinate Dehydrogenase A-Related Metastatic...

The study identifies the importance of positron emission tomographic (PET) and anatomic imaging modalities and their individual performances in detecting succinate dehydrogenase A (SDHA)-related metastatic pheochromocytoma and paraganglioma (PPGL). The detection rates of PET modalities-⁶⁸Ga-DOTATATE, ¹⁸F-FDG, and ¹⁸F-FDOPA-along with the combination of computed tomography (CT) and magnetic resonance imaging (MRI) are compared in a cohort of 11 patients with metastatic PPGL in the setting of a germline SDHA mutation. The imaging detection performances were evaluated at three levels: overall lesions, anatomic regions, and a patient-by-patient basis. ⁶⁸Ga-DOTATATE PET demonstrated a lesion-based detection rate of 88.6% [95% confidence interval (CI), 84.3-92.5%], while ¹⁸F-FDG, ¹⁸F-FDOPA, and CT/MRI showed detection rates of 82.9% (CI, 78.0-87.1%), 39.8% (CI, 30.2-50.2%), and 58.2% (CI, 52.0-64.1%), respectively. The study found that ⁶⁸Ga-DOTATATE best detects lesions in a subset of patients with SDHA-related metastatic PPGL. However, ¹⁸F-FDG did detect more lesions in the liver, mediastinum, and abdomen/pelvis anatomic regions, showing the importance of a combined approach using both PET modalities in evaluating SDHA-related PPGL.