title: Selective internal radiation therapy: quantifying distal penetration and distribution of resin and glass microspheres in a surrogate arterial model.
abstract: OBJECTIVE
  To experimentally investigate the effects of microsphere density and diameter on distal penetration.
  
  
  METHODS
  A surrogate hepatic arterial system was developed to replicate the hemodynamics (pressures, flow rates, pulsatile flow characteristics) and anatomic geometry (vessel diameters) proximal and distal to the microsphere injection point. A planar tumor model, placed distal to the injection point, allowed visualization of deposited microspheres. Bland resin and glass microspheres, with physical characteristics approximating the characteristics of commercially available products, were injected into the surrogate system. Microsphere type, injection rate, systemic flow rate, and tumor model inclination were varied among tests (glass, n = 7; resin, n = 6) with replicates for 2 conditions. After injection, 254 micrographs were obtained at previously defined locations throughout the tumor model to document microsphere distributions. Average microsphere distributions and mass measurements of microspheres collected at the tumor outlet were analyzed to quantify distal penetration for each case.
  
  
  RESULTS
  Across all test conditions, average penetration depths of resin microspheres were higher compared with glass microspheres (45.1 cm ± 11.8 vs 22.3 cm ± 9.9). The analysis of variance indicated that the observed difference between microsphere type (glass vs resin) was significant (P = .005, df = 1,2). The observed distance means did not differ significantly across flow rate or inclination angle.
  
  
  CONCLUSIONS
  Penetration depths of resin microspheres were significantly higher than penetration depths of glass microspheres in the surrogate hepatic arterial system.
authors.affiliation: Departments of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, Raleigh NC 27695.
authors.forename: Shaphan R
authors.initials: SR
authors.lastname: Jernigan
authors.affiliation: Statistics, North Carolina State University, Campus Box 7910, Raleigh NC 27695.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Osborne
authors.affiliation: Biomedical Engineering, North Carolina State University, Campus Box 7910, Raleigh NC 27695.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Mirek
authors.affiliation: Departments of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, Raleigh NC 27695.; Biomedical Engineering, North Carolina State University, Campus Box 7910, Raleigh NC 27695.. Electronic address: greg_buckner@ncsu.edu.
authors.forename: Gregory
authors.initials: G
authors.lastname: Buckner
mesh_terms: D000818:Animals; D004621:Embolization, Therapeutic / Q000379:methods*; D005898:Glass / Q000737:chemistry*; D006439:Hemodynamics; D006499:Hepatic Artery / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007269:Injections, Intra-Arterial; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000098:blood supply / Q000473:pathology / Q000532:radiotherapy*; D008863:Microspheres; D008953:Models, Anatomic; D010316:Particle Size; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D012117:Resins, Synthetic / Q000737:chemistry*; D013668:Technetium Tc 99m Aggregated Albumin / Q000008:administration & dosage*
chemical_list: D019275:Radiopharmaceuticals; D012117:Resins, Synthetic; D013668:Technetium Tc 99m Aggregated Albumin