title: Development of 68Ga-glycopeptide as an imaging probe for tumor angiogenesis.
abstract: Objective. This study was aimed to study tissue distribution and tumor imaging potential of (68)Ga-glycopeptide (GP) in tumor-bearing rodents by PET. Methods. GP was synthesized by conjugating glutamate peptide and chitosan. GP was labeled with (68)Ga chloride for in vitro and in vivo studies. Computer outlined region of interest (counts per pixel) of the tumor and muscle (at the symmetric site) was used to determine tumor-to-muscle count density ratios. To ascertain the feasibility of (68)Ga-GP in tumor imaging in large animals, PET/CT imaging of (68)Ga-GP and (18)F-FDG were conducted in New Zealand white rabbits bearing VX2 tumors. Standard uptake value of tumors were determined by PET up to 45 min. To determine blood clearance and half-life of (68)Ga-GP, blood samples were collected from 10 seconds to 20 min. Results. Radiochemical purity of (68)Ga-GP determined by instant thin-layer chromatography was >95%. Tumor uptake values (SUV) for (68)Ga-GP and (18)F-FDG in New Zealand white rabbits bearing VX2 tumors were 3.25 versus 7.04. PET images in tumor-bearing rats and rabbits confirmed that (68)Ga-GP could assess tumor uptake. From blood clearance curve, the half-life of (68)Ga-GP was 1.84 hr. Conclusion Our data indicate that it is feasible to use (68)Ga-GP to assess tumor angiogenesis.
authors.affiliation: Division of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. ning.tsao@mdanderson.org
authors.forename: Ning
authors.initials: N
authors.lastname: Tsao
authors.forename: Chau-Hui
authors.initials: CH
authors.lastname: Wang
authors.forename: Li-Jane
authors.initials: LJ
authors.lastname: Her
authors.forename: Kai-Yuan
authors.initials: KY
authors.lastname: Tzen
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Chen
authors.forename: Dong-Fang
authors.initials: DF
authors.lastname: Yu
authors.forename: David J
authors.initials: DJ
authors.lastname: Yang
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging; D002850:Chromatography, Gel; D004307:Dose-Response Relationship, Radiation; D019075:Electrophoresis, Capillary; D005260:Female; D005710:Gallium Radioisotopes; D006020:Glycopeptides / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D006207:Half-Life; D009369:Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D011817:Rabbits; D051381:Rats; D011916:Rats, Inbred F344; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed
chemical_list: D005710:Gallium Radioisotopes; D006020:Glycopeptides