title: Comparative somatostatin receptor scintigraphy using in-111-DOTA-lanreotide and in-111-DOTA-Tyr3-octreotide versus F-18-FDG-PET for evaluation of somatostatin receptor-mediated radionuclide therapy.
abstract: BACKGROUND
  Based on the high number of somatostatin (SST) receptors expressed by neuroendocrine tumors, long-acting SST analogs have been successfully used for tumor detection. New developments point to the potential use of these types of radioligands for tumor-specific radionuclide therapy.
  
  
  METHODS
  We have comparatively investigated the diagnostic capacity of the SST analog. 111In-DOTA-lanreotide (LAN), as opposed to 111ln-DOTA-DPhe1-Tyr3-octreotide (TOCT) in tumor patients. This article gives an overview of recent scintigraphic results compared to CT/MRI, 18F-FDG-PET, endoscopy and/or surgery in a threshold of 218 tumor patients.
  
  
  RESULTS
  As opposed to radiology, previously unknown tumor lesions were demonstrable by either SST radioligand in about one third of patients. In carcinoid patients, the SST scan sensitivity was 64% for LAN (18 of 28) and 87% (34 of 39) for TOCT, whereas the sensitivity was 100% in patients with (radioiodine-negative) thyroid cancer (17 of 17) for LAN and 95% for TOCT (20 of 21). Discordant scintigraphic results between LAN and TOCT (higher tumor uptake and/or visualisation of different lesions in the same patient) were also seen in patients with lymphoma, lung cancer and intestinal adenocarcinoma. In a direct comparison of both SST tracers in 38 tumor patients, LAN gave positive results in 35 of 38, TOCT in 36 of 38 and 18F-FDG-PET in 14 of 22 of the same patients. SST scan results obtained by both tracers were equivocal in 23 of 38 patients, but were better in 10 patients withTOCTand in 5 patients with LAN.
  
  
  CONCLUSIONS
  We conclude that both SST radioligands are suitable tracers for tumor imaging, but may give significantly different uptake results for different tumor types. Since the uptake is most important for tumor therapy, using either longacting SSTanalogs, and/or 90Y-labeled analogs, careful evaluation should be made prior to therapy.
authors.affiliation: Department of Nuclear Medicine, University of Vienna, Austria. irene.virgolini@akh-wien.ac.at
authors.forename: I
authors.initials: I
authors.lastname: Virgolini
authors.forename: P
authors.initials: P
authors.lastname: Patri
authors.forename: C
authors.initials: C
authors.lastname: Novotny
authors.forename: T
authors.initials: T
authors.lastname: Traub
authors.forename: M
authors.initials: M
authors.lastname: Leimer
authors.forename: B
authors.initials: B
authors.lastname: Füger
authors.forename: S R
authors.initials: SR
authors.lastname: Li
authors.forename: P
authors.initials: P
authors.lastname: Angelberger
authors.forename: M
authors.initials: M
authors.lastname: Raderer
authors.forename: S
authors.initials: S
authors.lastname: Wogritsch
authors.forename: A
authors.initials: A
authors.lastname: Kurtaran
authors.forename: K
authors.initials: K
authors.lastname: Kletter
authors.forename: R
authors.initials: R
authors.lastname: Dudczak
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy; D000328:Adult; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D019788:Fluorodeoxyglucose F18; D006571:Heterocyclic Compounds; D006801:Humans; D007414:Intestinal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D008024:Ligands; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D008223:Lymphoma / Q000000981:diagnostic imaging / Q000532:radiotherapy; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D015282:Octreotide; D010456:Peptides, Cyclic; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000032:analysis* / Q000096:biosynthesis; D014055:Tomography, Emission-Computed / Q000379:methods*; D014443:Tyrosine
chemical_list: D006571:Heterocyclic Compounds; D008024:Ligands; D010456:Peptides, Cyclic; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; C116409:indium 111-DOTA-lanreotide; D019788:Fluorodeoxyglucose F18; D014443:Tyrosine; D015282:Octreotide