title: Different radioactivity uptake between somatostatin analogues labelled with ¹¹¹In and ⁹⁰/⁸⁸Y in rat kidney.
abstract: Somatostatin receptor targeting is a valuable method to treat somatostatin receptor-positive tumours. In peptide receptor radionuclide therapy, it is essential to determine the highest activity that can be safely administered to the patient. As (90)Y emits no gamma rays, absorbed doses for (90)Y are usually estimated using the same peptide labelled with (111)In. The aim of the study was to determine if replacement of (90/88)Y by (111)In affects the biodistribution profile of five selected somatostatin analogues in preclinical experiments.
  
  
  METHODS
  Radiolabelled peptides were administered intravenously to male Wistar rats.
  
  
  RESULTS
  The peptides under study labelled either with (111)In or with (88/90)Y showed similar distribution profiles in all tissues excepting the kidney. The kidney radioactivity uptake was significantly lower for (88/90)Y-labeled peptide in comparison with the one of (111)In.
  
  
  CONCLUSIONS
  We conclude that a radiation-absorbed dose after (90)Y-labelled somatostatin analogues appears to be lower than that predicted by the (111)In-labelled peptide.
authors.affiliation: Faculty of Pharmacy, Charles University, Heyrovskeho 1203, CZ-50005 Hradec Kralove, Czech Republic. laznicek@faf.cuni.cz
authors.forename: Milan
authors.initials: M
authors.lastname: Laznicek
authors.forename: Alice
authors.initials: A
authors.lastname: Laznickova
mesh_terms: D000818:Animals; D007205:Indium Radioisotopes / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism*; D015021:Yttrium Radioisotopes / Q000378:metabolism*
chemical_list: D007205:Indium Radioisotopes; D015021:Yttrium Radioisotopes; D013004:Somatostatin