Comparison of 6-¹⁸F-Fluoro-l-DOPA, ¹⁸F-2-deoxy-d- glucose, CT, and MRI in patients with pancreatic neuroendocrine neoplasms with von Hippel-Lindau disease

Introduction: There are limited data on the utility of 6- ¹⁸F-fluoro-l-3,4-dihydroxyphenylalanine (¹⁸F-DOPA) and ¹⁸F-2-deoxy-d-glucose (¹⁸F-FDG) in the workup of patients with pancreatic neuroendocrine tumors (PNETs). The aim of our study was to determine the accuracy of ¹⁸F-DOPA and ¹⁸F-FDG to detect PNETs in patients with von Hippel-Lindau disease (vHL). Methods: We studied prospectively 69 patients with a diagnosis of vHL and pancreatic lesion(s) using computed tomography (CT), magnetic resonance imaging (MRI), ¹⁸F-FDG, and ¹⁸F-DOPA. Clinical, genetic, and laboratory characteristics were analyzed to determine association with imaging study results. Results: In sum, 40 patients underwent evaluation by all 4 modalities; 98 PNETs and 55 PNETs were identified on CT and MRI, respectively. Only 11 of the 98 lesions (11%) were positive on ¹⁸F-DOPA and 45 of the 98 (46%) lesions were positive on ¹⁸F-FDG. There were 13 ¹⁸F-DOPA and 26 ¹⁸F-FDG avid extrapancreatic lesions. One patient underwent resection of an ¹⁸F-DOPA avid extrapancreatic lesion in the lung, with pathology demonstrating a NET. There was no association between ¹⁸F-DOPA and ¹⁸F-FDG avidity and tumor size, age, gender, vHL mutation, or serum chromogranin A level. Conclusion: ¹⁸F-FDG and MRI may be adjuncts to CT in identifying PNETs and metastatic disease. ¹⁸F-DOPA has limited value in identifying PNETs in patients with vHL, but may be useful for identifying extrapancreatic NET lesions.