title: Sonoporation as an enhancing method for boron neutron capture therapy for squamous cell carcinomas.
abstract: BACKGROUND
  Boron neutron capture therapy (BNCT) is a selective radiotherapy that is dependent on the accumulation of ¹⁰B compound in tumors. Low-intensity ultrasound produces a transient pore on cell membranes, sonoporation, which enables extracellular materials to enter cells. The effect of sonoporation on BNCT was examined in oral squamous cell carcinoma (SCC) xenografts in nude mice.
  
  
  METHODS
  Tumor-bearing mice were administrated boronophenylalanine (BPA) or boronocaptate sodium (BSH) intraperitoneally. Two hours later, tumors were subjected to sonoporation using microbubbles followed by neutron irradiation.
  
  
  RESULTS
  The ¹⁰B concentration was higher in tumors treated with sonoporation than in untreated tumors, although the difference was not significant in BPA. When tumors in mice that received BPA intraperitoneally were treated with sonoporation followed by exposure to thermal neutrons, tumor volume was markedly reduced and the survival rate was prolonged. Such enhancements by sonoporation were not observed in mice treated with BSH-mediated BNCT.
  
  
  CONCLUSIONS
  These results indicate that sonoporation enhances the efficiency of BPA-mediated BNCT for oral SCC. Sonoporation may modulate the microlocalization of BPA and BSH in tumors and increase their intracellular levels.
authors.forename: Naofumi
authors.initials: N
authors.lastname: Yamatomo
authors.forename: Takaki
authors.initials: T
authors.lastname: Iwagami
authors.forename: Itsuro
authors.initials: I
authors.lastname: Kato
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Masunaga
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Sakurai
authors.forename: Soichi
authors.initials: S
authors.lastname: Iwai
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakazawa
authors.forename: Koji
authors.initials: K
authors.lastname: Ono
authors.affiliation: Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Yamadaoka 1-8, Suita, Osaka, 565-0871, Japan. yura@dent.osaka-u.ac.jp.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yura
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000737:chemistry; D016754:Boron Neutron Capture Therapy / Q000379:methods*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000528:radiation effects; D005260:Female; D006801:Humans; D007554:Isotopes / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D045423:Microbubbles; D009062:Mouth Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009368:Neoplasm Transplantation; D009502:Neutrons; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D011878:Radiotherapy / Q000379:methods*; D014465:Ultrasonics / Q000379:methods*
chemical_list: D001896:Boron Compounds; D007554:Isotopes; D010649:Phenylalanine; C033685:4-boronophenylalanine