title: GRP receptor imaging of prostate cancer using [(99m)Tc]Demobesin 4: a first-in-man study.
abstract: OBJECTIVE
  We explored the imaging of bombesin receptors and evaluated the clinical use of [(99m)Tc]Demobesin 4 ([(99m)Tc]DB4) in prostate cancer patients.
  
  
  METHODS
  [(99m)Tc]DB4 was prepared according to Good Manufacturing Practice. Patients with prostate cancer underwent serial planar and SPECT imaging up to 3 h after administration. Blood and urine samples were taken to assess pharmacokinetics.
  
  
  RESULTS
  [(99m)Tc]DB4 is safe and clears rapidly from the bloodstream via the kidneys resulting in low background activity. The tracer binds strongly to the gastrin-releasing peptide receptor (GRPR) in vivo as indicated by the high uptake in the pancreas seen in all patients. In patients who had undergone hormone therapy, [(99m)Tc]DB4 did not efficiently image metastatic prostate cancer. In contrast, in newly diagnosed patients local disease was visualised.
  
  
  CONCLUSIONS
  The GRPR is an unsuitable target for imaging refractory prostate cancer but may be useful in untreated disease. [(99m)Tc]DB4 is a promising radiopharmaceutical which merits further exploration in this specific group of patients.
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, London, EC1M 6BQ, UK, s.j.mather@qmul.ac.uk.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Mather
authors.forename: Berthold A
authors.initials: BA
authors.lastname: Nock
authors.forename: Theodosia
authors.initials: T
authors.lastname: Maina
authors.forename: Vickie
authors.initials: V
authors.lastname: Gibson
authors.forename: David
authors.initials: D
authors.lastname: Ellison
authors.forename: Iain
authors.initials: I
authors.lastname: Murray
authors.forename: Ravin
authors.initials: R
authors.lastname: Sobnack
authors.forename: Steve
authors.initials: S
authors.lastname: Colebrook
authors.forename: Susan
authors.initials: S
authors.lastname: Wan
authors.forename: Gavin
authors.initials: G
authors.lastname: Halberrt
authors.forename: Teresa
authors.initials: T
authors.lastname: Szysko
authors.forename: Thomas
authors.initials: T
authors.lastname: Powles
authors.forename: Norbert
authors.initials: N
authors.lastname: Avril
mesh_terms: D000368:Aged; D001839:Bombesin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D018004:Receptors, Bombesin / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D018004:Receptors, Bombesin; C477441:technetium 99m demobesin 1; D001839:Bombesin