title: Improved Hyperthermia Treatment of Tumors Under Consideration of Magnetic Nanoparticle Distribution Using Micro-CT Imaging.
abstract: OBJECTIVE
  Heterogeneous magnetic nanoparticle (MNP) distributions within tumors can cause regions of temperature under dosage and reduce the therapeutic efficiency. Here, micro-computed tomography (CT) imaging was used as a tool to determine the MNP distribution in vivo. The therapeutic success was evaluated based on tumor volume and temperature distribution.
  
  
  METHODS
  Tumor-bearing mice were intratumorally injected with iron oxide particles. MNP distribution was assessed by micro-CT with a low radiation dose protocol.
  
  
  RESULTS
  MNPs were clearly visible, and the exact distribution to nontumor structures was detected by micro-CT. Knowledge of the intratumoral MNP distribution allowed the generation of higher temperatures within the tumor and led to higher temperature values after exposure to an alternating magnetic field (AMF). Consequently, the tumor size after 28 days was reduced to 14 and 73 % of the initial tumor volume for the MNP/AMF/CT and MNP/AMF groups, respectively.
  
  
  CONCLUSIONS
  The MNP distribution pattern mainly governed the generated temperature spots in the tumor. Knowing the MNP distribution enabled individualized hyperthermia treatment and improved the overall therapeutic efficiency.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Dähring
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Grandke
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Teichgräber
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Bachstraße 18, 07740, Jena, Germany. Ingrid.Hilger@med.uni-jena.de.
authors.forename: I
authors.initials: I
authors.lastname: Hilger
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D008280:Magnetics; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D055114:X-Ray Microtomography / Q000379:methods*
keywords: In vivo; Intratumoral MNP distributon; Iron oxide nanoparticles; Magnetic fluid hyperthermia; Micro-CT imaging; Temperature distribution; Therapeutic efficiency; Tumor volume