Comparison of 68 Ga-DOTANOC and 18 F-FDOPA PET/CT for Detection of Recurrent or Metastatic Paragangliomas

Purpose To evaluate the diagnostic performance of gallium 68 ( Ga)-DOTA-NaI3-octreotide ( Ga-DOTANOC) and fluorine 18 ( F)-fluoro-l-3,4-dihydroxyphenylalanine ( F-FDOPA) PET/CT in detecting recurrent or metastatic paragangliomas. Materials and Methods This single-center retrospective study included patients with paragangliomas who underwent both Ga-DOTANOC PET/CT and F-FDOPA PET/CT between August 2021 and December 2023. The diagnostic performance of these two tracers in detecting recurrent or metastatic tumors was compared using several metrics, including sensitivity, negative predictive value, and accuracy. Results This study included 36 patients (median age, 52 years [range, 14-78 years]; 16 female, 20 male). Of these, nine underwent initial Ga-DOTANOC and F-FDOPA PET/CT examinations before treatment, and the remaining 27 underwent posttreatment examinations. Twenty-two of those 27 patients had recurrence or metastasis. According to lesion-level analysis, Ga-DOTANOC had higher sensitivity, negative predictive value, and accuracy for diagnosis of bone metastases than did F-FDOPA PET/CT (97% vs 78% [ < .001], 85% vs 42% [ = .02], and 97% vs 81% [ < .001], respectively). F-FDOPA PET/CT had higher sensitivity, negative predictive value, and accuracy for the diagnosis of liver metastases than did Ga-DOTANOC PET/CT (73% vs 15% [ < .001], 68% vs 41% [ = .04], and 83% vs 46% [ < .001], respectively). According to patient-level analysis, the sensitivity of F-FDOPA PET/CT for diagnosing liver metastases was higher than that of Ga-DOTANOC PET/CT (88% vs 25%; = .04). Conclusion In patients with recurrent or metastatic paragangliomas, Ga-DOTANOC PET/CT showed better performance than F-FDOPA PET/CT in detecting bone metastases, and F-FDOPA PET/CT performed better in detecting liver metastases. Ga-DOTANOC, F-FDOPA, Pheochromocytoma, Paraganglioma Published under a CC BY 4.0 license.