title: Intraindividual comparison of selective arterial versus venous 68Ga-DOTATOC PET/CT in patients with gastroenteropancreatic neuroendocrine tumors.
abstract: OBJECTIVE
  Therapy with the somatostatin analogue DOTA-(0)-Phe(1)-Tyr(3)-octreotide (DOTATOC) labeled with a beta-(DOTA-Phe-Tyr-Octreotide) emitter such as 90Y or 177Lu is accepted for the palliative treatment of unresectable neuroendocrine cancer. However, the optimal route of administration has not been determined. Using positron-emission tomography (PET)-labeled 68Ga-DOTATOC, we compared selective tumoral uptake on PET/computed tomography (CT) after arterial or venous administration of the agent in patients with gastroenteropancreatic neuroendocrine tumor.
  
  
  METHODS
  Fifteen patients with neuroendocrine cancer were examined with 68Ga-DOTATOC PET/CT after intravenous (i.v.) and intraarterial (i.a.) administration within 4 weeks of each other and without any intervening therapy. Eleven patients had multifocal metastases, six were considered to have unresectable primary tumor. The intraarterial catheter was placed in the vessel supplying the main tumor burden. The standard uptake value (SUV) was used to compare intratumoral concentrations of 68Ga-DOTATOC.
  
  
  RESULTS
  Compared with i.v. infusion, the i.a. infusion resulted in an increased SUV in 117 of 122 (96%) liver metastases. The average increase in SUV was 3.75-fold higher with i.a. administration. The increase in uptake for the primary tumors was dependent on the selectivity of the catheter placement, resulting in variable increases in SUV after i.a. injection (1.44- to 7.8-fold higher).
  
  
  CONCLUSIONS
  This study showed that uptake of DOTATOC is commonly several fold higher after selective i.a. administration in comparison with i.v. injection in both the primary tumor as well as in liver metastases of neuroendocrine cancer. Therefore, intraarterial DOTATOC is a promising drug for regionally intensified radiopeptide therapy.
authors.affiliation: Department of Nuclear Medicine, Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany. Clemens.kratochwil@med.uni-heidelberg.de
authors.forename: Clemens
authors.initials: C
authors.lastname: Kratochwil
authors.forename: Frederik L
authors.initials: FL
authors.lastname: Giesel
authors.forename: Ruben
authors.initials: R
authors.lastname: López-Benítez
authors.forename: Nadine
authors.initials: N
authors.lastname: Schimpfky
authors.forename: Kirsten
authors.initials: K
authors.lastname: Kunze
authors.forename: Michael
authors.initials: M
authors.lastname: Eisenhut
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
mesh_terms: D000328:Adult; D000368:Aged; D004067:Digestive System Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D009942:Organometallic Compounds / Q000008:administration & dosage*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D011878:Radiotherapy / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: C504894:68Ga-DOTANOC; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals