Neuroendocrine Tumor Imaging
¹¹¹In-Octreotide

•  PATIENT INDICATIONS
   
  • ¹¹¹In-Octreotide is indicated for the scintigraphic localization of  primary and metastatic neuroendocrine tumors bearing somatostatin receptors.
  
   

• TUMOR TYPES IMAGED

  Neuroblastomas

  Pheochromocytomas

  Paraganglioma

  Carcinoid Tumors

  Medullary Thyroid Ca

  VIPoma

  Insulinomas

  Gastrinomas

  Pituitary Adenoma

  Glucagonoma

  Islet Cell Carcinomas

  Small Cell Lung Ca

                                 

• CHARACTERISTICS OF ¹¹¹In

  •  t_phys = 2.805 d  =  67.32 hr
     

  • 171.3 keV gamma: 90.2% abundance
     

  • 245.4 keV gamma: 94.0% abundance

   

• RADIOTRACER USED 

  • 3-6 mCi of high purity ¹¹¹InCl₃ in dilute HCl in a 10 ml vial

   

• RADIOCHEMICAL REACTION 

  In³⁺ + DTPA-Octreotide   ------------->  In DTPA-octreotide

  final pH: 3.8-4.3

   

• BASIC LABELING THEORY

  • DTPA group is covalently bonded to Octreotide molecule
     

  • ¹¹¹In actually bonds to DTPA portion of molecule, not to octreotide molecular structure

   

   

• MOLECULAR STRUCTURE OF OCTREOTIDE