title: Evaluation of side effects of radiofrequency capacitive hyperthermia with magnetite on the blood vessel walls of tumor metastatic lesion surrounding the abdominal large vessels: an agar phantom study.
abstract: BACKGROUND
  Magnetite used in an 8-MHz radiofrequency (RF) capacitive heating device can increase the temperature of a specific site up to 45°C. When treating a metastatic lesion around large abdominal vessels via hyperthermia with magnetite, heating-induced adverse effects on these vessels need to be considered. Therefore, this study examined hyperthermia-induced damage to blood vessel walls in vitro.
  
  
  METHODS
  A large agar phantom with a circulatory system consisting of a swine artery and vein connected to a peristaltic pump was prepared. The blood vessels were placed on the magnetite-containing agar piece. Heating was continued for 30 min at 45°C. After heating, a histological study for injury to the blood vessels was performed.
  
  
  RESULTS
  The inner membrane temperature did not reach 45°C due to the cooling effect of the blood flow. In the heated vessels, vascular wall collagen degenerated and smooth muscle cells were narrowed; however, no serious changes were noted in the vascular endothelial cells or vascular wall elastic fibers. The heated vessel wall was not severely damaged; this was attributed to cooling by the blood flow.
  
  
  CONCLUSIONS
  Our findings indicate that RF capacitive heating therapy with magnetite may be used for metastatic lesions without injuring the surrounding large abdominal vessels.
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Kawai
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Kobayashi
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yasui
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Umemoto
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Mizuno
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okada
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tozawa
authors.affiliation: College of Bioscience and Biotechnology, Chubu University, Kasugai, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kohri
keywords: Agar phantom study; Interstitial hyperthermia injury; Large vessels; Magnetic cationic liposome; Vascular cell damage
references.citation: Biol Reprod. 1995 Sep;53(3):598-608
references.pmid: 7578684
references.citation: Prostate. 2005 Sep 1;64(4):373-81
references.pmid: 15754344
references.citation: IEEE Trans Biomed Eng. 1984 Jan;31(1):53-62
references.pmid: 6724610
references.citation: Am J Surg Pathol. 1995 Jun;19(6):709-11
references.pmid: 7538733
references.citation: Jpn J Cancer Res. 2002 Jan;93(1):103-8
references.pmid: 11802814
references.citation: Int J Hyperthermia. 1993 Jan-Feb;9(1):51-68
references.pmid: 8433026
references.citation: Prostate. 2008 May 15;68(7):784-92
references.pmid: 18302228
references.citation: Eur J Cancer. 1972 Oct;8(5):573-5
references.pmid: 4651789
references.citation: Int J Hyperthermia. 1997 May-Jun;13(3):325-36
references.pmid: 9222815
references.citation: J Biomech Eng. 2009 Jan;131(1):011001
references.pmid: 19045917
references.citation: Jpn J Cancer Res. 1999 Jun;90(6):699-704
references.pmid: 10429664
references.citation: Clin Physiol Funct Imaging. 2007 May;27(3):185-90
references.pmid: 17445070
references.citation: Jpn J Cancer Res. 1998 Apr;89(4):463-9
references.pmid: 9617354
references.citation: Jpn J Cancer Res. 1997 Jul;88(7):630-2
references.pmid: 9310134
references.citation: Jpn J Cancer Res. 1996 Nov;87(11):1179-83
references.pmid: 9045948
references.citation: Prostate. 2006 May 15;66(7):718-27
references.pmid: 16425185
references.citation: Eur J Vasc Endovasc Surg. 1996 Feb;11(2):230-7
references.pmid: 8616659