PT - JOURNAL ARTICLE AU - van Berkel, Anouk AU - Rao, Jyotsna U. AU - Kusters, Benno AU - Demir, Tuna AU - Visser, Eric AU - Mensenkamp, Arjen R. AU - van der Laak, Jeroen A.W.M. AU - Oosterwijk, Egbert AU - Lenders, Jacques W.M AU - Sweep, Fred C.G.J. AU - Wevers, Ron A. AU - Hermus, Ad R. AU - Langenhuijsen, Johan F. AU - Kunst, Dirk P.M. AU - Pacak, Karel AU - Gotthardt, Martin AU - Timmers, Henri J.L.M. TI - Correlation Between In Vivo <sup>18</sup>F-FDG PET and Immunohistochemical Markers of Glucose Uptake and Metabolism in Pheochromocytoma and Paraganglioma AID - 10.2967/jnumed.114.137034 DP - 2014 Aug 01 TA - Journal of Nuclear Medicine PG - 1253--1259 VI - 55 IP - 8 4099 - http://jnm.snmjournals.org/content/55/8/1253.short 4100 - http://jnm.snmjournals.org/content/55/8/1253.full SO - J Nucl Med2014 Aug 01; 55 AB - Pheochromocytomas and paragangliomas (PPGLs) can be localized by 18F-FDG PET. The uptake is particularly high in tumors with an underlying succinate dehydrogenase (SDH) mutation. SDHx-related PPGLs are characterized by compromised oxidative phosphorylation and a pseudohypoxic response, which mediates an increase in aerobic glycolysis, also known as the Warburg effect. The aim of this study was to explore the hypothesis that increased uptake of 18F-FDG in SDHx-related PPGLs is reflective of increased glycolytic activity and is correlated with expression of different proteins involved in glucose uptake and metabolism through the glycolytic pathway. Methods: Twenty-seven PPGLs collected from patients with hereditary mutations in SDHB (n = 2), SDHD (n = 3), RET (n = 5), neurofibromatosis 1 (n = 1), and myc-associated factor X (n = 1) and sporadic patients (n = 15) were investigated. Preoperative 18F-FDG PET/CT studies were analyzed; mean and maximum standardized uptake values (SUVs) in manually drawn regions of interest were calculated. The expression of proteins involved in glucose uptake (glucose transporters types 1 and 3 [GLUT-1 and -3, respectively]), phosphorylation (hexokinases 1, 2, and 3 [HK-1, -2, and -3, respectively]), glycolysis (monocarboxylate transporter type 4 [MCT-4]), and angiogenesis (vascular endothelial growth factor [VEGF], CD34) were examined in paraffin-embedded tumor tissues using immunohistochemical staining with peroxidase-catalyzed polymerization of diaminobenzidine as a read-out. The expression was correlated with corresponding SUVs. Results: Both maximum and mean SUVs for SDHx-related tumors were significantly higher than those for sporadic and other hereditary tumors (P &lt; 0.01). The expression of HK-2 and HK-3 was significantly higher in SDHx-related PPGLs than in sporadic PPGLs (P = 0.022 and 0.025, respectively). The expression of HK-2 and VEGF was significantly higher in SDHx-related PPGLs than in other hereditary PPGLs (P = 0.039 and 0.008, respectively). No statistical differences in the expression were observed for GLUT-1, GLUT-3, and MCT-4. The percentage anti-CD 34 staining and mean vessel perimeter were significantly higher in SDHx-related PPGLs than in sporadic tumors (P = 0.050 and 0.010, respectively). Mean SUVs significantly correlated with the expression of HK-2 (P = 0.027), HK-3 (P = 0.013), VEGF (P = 0.049), and MCT-4 (P = 0.020). Conclusion: The activation of aerobic glycolysis in SDHx-related PPGLs is associated with increased 18F-FDG accumulation due to accelerated glucose phosphorylation by hexokinases rather than increased expression of glucose transporters.