title: Identification of infusion strategy for achieving repeatable nanoparticle distribution and quantification of thermal dosage using micro-CT Hounsfield unit in magnetic nanoparticle hyperthermia.
abstract: OBJECTIVE
  The objective of this study was to identify an injection strategy leading to repeatable nanoparticle deposition patterns in tumours and to quantify volumetric heat generation rate distribution based on micro-CT Hounsfield unit (HU) in magnetic nanoparticle hyperthermia.
  
  
  METHODS
  In vivo animal experiments were performed on graft prostatic cancer (PC3) tumours in immunodeficient mice to investigate whether lowering ferrofluid infusion rate improves control of the distribution of magnetic nanoparticles in tumour tissue. Nanoparticle distribution volume obtained from micro-CT scan was used to evaluate spreading of the nanoparticles from the injection site in tumours. Heating experiments were performed to quantify relationships among micro-CT HU values, local nanoparticle concentrations in the tumours, and the ferrofluid-induced volumetric heat generation rate (q(MNH)) when nanoparticles were subject to an alternating magnetic field.
  
  
  RESULTS
  An infusion rate of 3 µL/min was identified to result in the most repeatable nanoparticle distribution in PC3 tumours. Linear relationships have been obtained to first convert micro-CT greyscale values to HU values, then to local nanoparticle concentrations, and finally to nanoparticle-induced q(MNH) values. The total energy deposition rate in tumours was calculated and the observed similarity in total energy deposition rates in all three infusion rate groups suggests improvement in minimising nanoparticle leakage from the tumours. The results of this study demonstrate that micro-CT generated q(MNH) distribution and tumour physical models improve predicting capability of heat transfer simulation for designing reliable treatment protocols using magnetic nanoparticle hyperthermia.
authors.affiliation: a Department of Mechanical Engineering , University of Maryland Baltimore County , Baltimore and.
authors.forename: Alexander
authors.initials: A
authors.lastname: LeBrun
authors.affiliation: b Department of Biology , University of Maryland Baltimore County , Baltimore , Maryland , USA.
authors.forename: Tejashree
authors.initials: T
authors.lastname: Joglekar
authors.affiliation: b Department of Biology , University of Maryland Baltimore County , Baltimore , Maryland , USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Bieberich
authors.affiliation: a Department of Mechanical Engineering , University of Maryland Baltimore County , Baltimore and.
authors.forename: Ronghui
authors.initials: R
authors.lastname: Ma
authors.affiliation: a Department of Mechanical Engineering , University of Maryland Baltimore County , Baltimore and.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D007267:Injections; D058185:Magnetite Nanoparticles / Q000008:administration & dosage* / Q000627:therapeutic use; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000628:therapy*; D055114:X-Ray Microtomography
chemical_list: D058185:Magnetite Nanoparticles
keywords: Bioheat transfer; image-based simulation; injection strategy; magnetic nanoparticle hyperthermia; micro-CT HU