title: Magnetic Heating of Nanoparticles: The Importance of Particle Clustering to Achieve Therapeutic Temperatures.
abstract: Hyperthermia therapy for cancer treatment seeks to destroy tumors through heating alone or combined with other therapies at elevated temperatures between 41.8 and 48 °C. Various forms of cell death including apoptosis and necrosis occur depending on temperature and heating time. Effective tumoricidal effects can also be produced by inducing damage to the tissue vasculature and stroma; however, surrounding normal tissue must be spared to a large extent. Magnetic nanoparticles have been under experimental investigation in recent years as a means to provide a favorable therapeutic ratio for local hyperthermia; however, practical numerical models that can be used to study the underlying mechanisms in realistic geometries have not previously appeared to our knowledge. Useful numerical modeling of these experiments is made extremely difficult by the many orders of magnitude in the geometries: from nanometers to centimeters. What has been missing is a practical numerical modeling approach that can be used to more deeply understand the experiments. We develop and present numerical models that reveal the extent and dominance of the local heat transfer boundary conditions, and provide a new approach that may simplify the numerical problem sufficiently to make ordinary computing machinery capable of generating useful predictions. The objectives of this paper are to place the discussion in a convenient interchangeable classical electromagnetic formulation, and to develop useful engineering approximations to the larger multiscale numerical modeling problem that can potentially be used in experiment evaluation; and eventually, may prove useful in treatment planning. We cast the basic heating mechanisms in the framework of classical electromagnetic field theory and provide calibrating analytical calculations and preliminary experimental results on BNF-Starch®nanoparticles in a mouse tumor model for perspective.
authors.affiliation: Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, TX 78712 e-mail:  jpearce@mail.utexas.edu.
authors.forename: John
authors.initials: J
authors.lastname: Pearce
authors.forename: Andrew
authors.initials: A
authors.lastname: Giustini
authors.forename: Robert
authors.initials: R
authors.lastname: Stigliano
authors.forename: P
authors.initials: P
authors.lastname: Jack Hoopes
references.citation: Int J Hyperthermia. 2002 May-Jun;18(3):194-202
references.pmid: 12028637
references.citation: Nanotechnology. 2011 Aug 26;22(34):345101
references.pmid: 21795772
references.citation: Invest Radiol. 1997 Nov;32(11):705-12
references.pmid: 9387059
references.citation: Med Hypotheses. 1979 Jan;5(1):83-102
references.pmid: 459972
references.citation: J Phys Chem B. 2006 Jun 8;110(22):10701-7
references.pmid: 16771316
references.citation: Nanotechnology. 2009 Sep 30;20(39):395103
references.pmid: 19726837
references.citation: Proc SPIE Int Soc Opt Eng. 2011 Feb 10;7901:
references.pmid: 24382988
references.citation: Nanotechnology. 2010 Jan 8;21(1):015706
references.pmid: 19946160
references.citation: IEEE Trans Biomed Eng. 1984 Jan;31(1):70-5
references.pmid: 6724612
references.citation: Int J Hyperthermia. 2005 Nov;21(7):637-47
references.pmid: 16304715
references.citation: Nanomedicine (Lond). 2013 Jan;8(1):29-41
references.pmid: 23173694
references.citation: Proc SPIE Int Soc Opt Eng. 2009 Feb 23;7181:71810P
references.pmid: 25346583
references.citation: Ann Biomed Eng. 2013 Jan;41(1):78-88
references.pmid: 22855120
references.citation: Proc SPIE Int Soc Opt Eng. 2009 Feb 23;7181:71810O
references.pmid: 25346582
references.citation: J Nanobiotechnology. 2008 Jan 30;6:2
references.pmid: 18234109
references.citation: Proc SPIE Int Soc Opt Eng. 2011 Feb 22;7901:
references.pmid: 24386534