title: Positron-emitting resin microspheres as surrogates of 90Y SIR-Spheres: a radiolabeling and stability study.
abstract: Commercially available resin microspheres and SIR-Spheres were labeled with metallic positron emitters and evaluated as positron emission tomography (PET) imaging surrogates of (90)Y SIR-Spheres. Radiolabeling was performed using a batch method, and in vitro stability over 24 h was evaluated in saline at physiological pH at 37 degrees C. The activity per microsphere distribution, as evaluated by autoradiography, showed the activity per microsphere to be proportional to the square radius of the spheres, suggesting surface binding. The in vivo stability of radiolabeling was evaluated in rats by micro-PET imaging after the intravenous injection of labeled microspheres. The different resin microspheres and radionuclides evaluated in this study all showed good radiolabeling efficiency and in vitro stability. However, only resins labeled with (86)Y and (89)Zr proved to have the in vivo stability required for clinical applications.
authors.affiliation: Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA. maavilarodri@wisc.edu
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Avila-Rodriguez
authors.forename: Reed G
authors.initials: RG
authors.lastname: Selwyn
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Hampel
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Thomadsen
authors.forename: Onofre T
authors.initials: OT
authors.lastname: Dejesus
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Converse
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Nickles
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D004337:Drug Carriers / Q000737:chemistry; D004355:Drug Stability; D008297:Male; D008657:Metabolic Clearance Rate; D008863:Microspheres; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D015021:Yttrium Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D000180:Acrylic Resins; D004337:Drug Carriers; D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes