title: Feasibility evaluation of neutron capture therapy for hepatocellular carcinoma using selective enhancement of boron accumulation in tumour with intra-arterial administration of boron-entrapped water-in-oil-in-water emulsion.
abstract: BACKGROUND
  Hepatocellular carcinoma (HCC) is one of the most difficult to cure with surgery, chemotherapy, or other combinational therapies. In the treatment of HCC, only 30% patients can be operated due to complication of liver cirrhosis or multiple intrahepatic tumours. Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between (10)B atoms and thermal neutrons, so it is necessary to accumulate a sufficient quantity of (10)B atoms in tumour cells for effective tumour cell destruction by BNCT. Water-in-oil-in-water (WOW) emulsion has been used as the carrier of anti-cancer agents on intra-arterial injections in clinical. In this study, we prepared (10)BSH entrapped WOW emulsion by double emulsifying technique using iodized poppy-seed oil (IPSO), (10)BSH and surfactant, for selective intra-arterial infusion to HCC, and performed simulations of the irradiation in order to calculate the dose delivered to the patients.
  
  
  METHODS
  WOW emulsion was administrated with intra-arterial injections via proper hepatic artery on VX-2 rabbit hepatic tumour models. We simulated the irradiation of epithermal neutron and calculated the dose delivered to the tissues with JAEA computational dosimetry system (JCDS) at JRR4 reactor of Japan Atomic Research Institute, using the CT scans of a HCC patient.
  
  
  CONCLUSIONS
  The (10)B concentrations in VX-2 tumour obtained by delivery with WOW emulsion were superior to those by conventional IPSO mix emulsion. According to the rabbit model, the boron concentrations (ppm) in tumour, normal liver tissue, and blood are 61.7, 4.3, and 0.1, respectively. The results of the simulations show that normal liver biologically weighted dose is restricted to 4.9 Gy-Eq (CBE; liver tumour: 2.5, normal liver: 0.94); the maximum, minimum, and mean tumour weighted dose are 43.1, 7.3, and 21.8 Gy-Eq, respectively, in 40 min irradiation. In this study, we show that (10)B entrapped WOW emulsion could be applied to novel intra-arterial boron delivery carrier for BNCT, and we show the possibility to apply BNCT to HCC. We can irradiate tumours as selectively and safety as possible, reducing the effects on neighbouring healthy tissues.
authors.affiliation: Department of Nuclear Engineering & Management, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan. yanagie@n.t.u-tokyo.ac.jp
authors.forename: Hironobu
authors.initials: H
authors.lastname: Yanagie
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kumada
authors.forename: Takemi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Syushi
authors.initials: S
authors.lastname: Higashi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ikushima
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Morishita
authors.forename: Atsuko
authors.initials: A
authors.lastname: Shinohara
authors.forename: Mitsuteru
authors.initials: M
authors.lastname: Fijihara
authors.forename: Minoru
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Sakurai
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kajiyama
authors.forename: Ryohei
authors.initials: R
authors.lastname: Nishimura
authors.forename: Koji
authors.initials: K
authors.lastname: Ono
authors.forename: Jun
authors.initials: J
authors.lastname: Nakajima
authors.forename: Minoru
authors.initials: M
authors.lastname: Ono
authors.forename: Masazumi
authors.initials: M
authors.lastname: Eriguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D001895:Boron / Q000378:metabolism*; D016754:Boron Neutron Capture Therapy; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000532:radiotherapy*; D004655:Emulsions; D005240:Feasibility Studies; D007261:Infusions, Intra-Arterial; D008114:Liver Neoplasms, Experimental / Q000378:metabolism / Q000532:radiotherapy*; D009821:Oils; D011817:Rabbits; D014867:Water
chemical_list: D004655:Emulsions; D009821:Oils; D014867:Water; D001895:Boron