Quantitative [18F]FDOPA PET/CT for the characterization of biochemical phenotypes in paraganglioma and pheochromocytoma

Dahlmann, Paul; Onkes, Meike; Kunte, Sophie; Auer, Matthias K.; Disko, Ulrike; Wang, Katharina; Lottspeich, Christian; Stüfchen, Isabel; Schweizer, Júnia R.O.L.; Mansour, Nabeel; Brendel, Matthias ; Schmid-Tannwald, Christine; Fischer, Alessa; Nölting, Svenja; Auernhammer, Christoph J.; Reincke, Martin; Bidlingmaier, Martin; Werner, Rudolf A.; Kroiss, Matthias; Völter, Friederike (2025): Quantitative [18F]FDOPA PET/CT for the characterization of biochemical phenotypes in paraganglioma and pheochromocytoma. EJNMMI Reports, 9: 40. ISSN 3005-074X

Abstract

Aim/Introduction

[ 18 F]FDOPA PET/CT is one of the most frequently used functional imaging modalities for the diagnosis of pheochromocytoma and paraganglioma (PPGL). The biochemical secretion type of PPGL is crucial for patient management, being linked to varying aggressiveness and metastatic risk. The aim of this study is to compare the biochemical phenotype and secretion with uptake intensity and tumour volume on [ 18 F]FDOPA PET/CT.

Methods

All patients with sympathetic PPGL undergoing [ 18 F]FDOPA PET/CT and laboratory analysis at first diagnosis at LMU University Hospital between 03/2012 and 11/2023 were included. Metabolic tumour volume (MTV), SUVmax, SUVmean and total lesion uptake (TLU) were compared to biochemical secretion using Rho-Spearman’s correlation and linear regression correcting for age, gender and secretion type. Biochemical phenotypes were compared with Mann-Whitney-U-test, ROC analysis was used to test the diagnostic discriminative power of radioligand uptake.

Results

71 of 74 PPGL were [ 18 F]DOPA-positive. TLU and MTV showed a moderate to strong correlation with plasma and urinary normetanephrines ( R = 0.68–0.82, p < 0.001), plasma 3-methoxytyramine ( R = 0.50, p = 0.003) and urinary metanephrines ( R = 0.69–0.80, p < 0.001). Regression analysis revealed a significant relationship between biochemical secretion and TLU (r 2 = 0.45–0.52, p < 0.001). Compared to adrenergic PPGL, noradrenergic PPGL demonstrated an increased radioligand uptake ( p < 0.001). ROC analysis identified thresholds for SUVmax ( > 12.1) and SUVmean ( > 6.95) that moderately distinguished both phenotypes (AUC = 0.75-0.76).

Conclusion

Radioligand uptake on [ 18 F ]FDOPA PET/CT is associated with the biochemical phenotype of PPGL. This finding may facilitate the metabolic profiling of patients with suspected impaired or delayed laboratory results. Normetanephrine concentrations in plasma and 24-hour urine may be employed as predictive markers of MTV and TLU.

• Doc-Type: Article (LMU Hospital)
• Organisational unit (Faculties): 07 Medicine > Medical Center of the University of Munich > Medical Clinic and Outpatient Clinic IV (Endocrinology, nephrology, other sections); 07 Medicine > Medical Center of the University of Munich > Clinic and Polyclinic for Nuclear Medicine; 07 Medicine > Medical Center of the University of Munich > Clinic and Polyclinic for Radiology
• DFG subject classification of scientific disciplines: Life sciences
• DFG: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 390857198
• DFG: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 314061271
• DFG: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 491502892