title: Imaging characterization of benign and malignant pheochromocytoma or paraganglioma: comparison between MIBG uptake and MR signal intensity ratio.
abstract: OBJECTIVE
  We compared metaiodobenzylguanidine (MIBG) uptake and magnetic resonance (MR) signal intensity ratio in differentiating benign and malignant disease in patients with pheochromocytoma or paraganglioma.
  
  
  METHODS
  Eighteen patients (9 men, mean age 37 ± 8 years) with pheochromocytoma or paraganglioma underwent MR imaging and iodine-131 MIBG scintigraphy. MR signal intensity ratio was measured on T1 and T2-weighted images using region of interest analysis and intensity ratio of MIBG uptake was calculated for each tumor lesion on 48 h images.
  
  
  RESULTS
  A total of 28 tumor lesions was analyzed of which 12 were benign and 16 malignant. MIBG uptake intensity ratio was significantly higher in malignant lesions compared to benign (5.2 ± 2.4 and 2.9 ± 1.4, respectively, p < 0.01). On the contrary, no significant difference in tumor size and MR signal intensity ratio between malignant and benign tumor lesions was observed.
  
  
  CONCLUSIONS
  In patients with pheochromocytoma or paraganglioma, iodine-131 MIBG uptake is able to differentiate between benign and malignant disease, while MR imaging is not useful for this purpose. The higher MIBG uptake observed in malignant lesions could reflect major tumor storage of catecholamines compared to benign lesions.
authors: Department of Biomorphological and Functional Sciences, University Federico II, Naples, Italy. maurea@unina.it
authors: Simone
authors: S
authors: Maurea
authors: Alberto
authors: A
authors: Cuocolo
authors: Massimo
authors: M
authors: Imbriaco
authors: Teresa
authors: T
authors: Pellegrino
authors: Mario
authors: M
authors: Fusari
authors: Renato
authors: R
authors: Cuocolo
authors: Raffaele
authors: R
authors: Liuzzi
authors: Marco
authors: M
authors: Salvatore
mesh_terms: D019797:3-Iodobenzylguanidine / Q000378:metabolism*; D000328:Adult; D001692:Biological Transport; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism*; D011877:Radionuclide Imaging; D012189:Retrospective Studies
chemical_list: D019797:3-Iodobenzylguanidine