DOSIMETRIC EVALUATION FOR NEUTRON CAPTURE THERAPY TO HEPATOCELLULAR CARCINOMA USING INTRA-ARTERIAL ADMINISTRATION OF BORON-ENTRAPPED WATER-IN-OIL-IN-WATER EMULSION

摘要

Hepatocellular carcinoma (HCC) is one of the difficult to cure with combinational medical therapies. 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 efficient ~(10)B atoms to tumour cells for effective BNCT. We prepared ~(10)BSH entrapped Water-in-oil-in-water(WOW) emulsion for selective intra-arterial infusion to HCC, and performed preliminary dosimetry with Japan Atomic Research Institute Computational Dosimetry System using CTscan imaging of HCC patient. The ~(10)B concentrations in VX-2 tumour by WOW emulsion was superior to those by conventional emulsion. According to the rabbit model, the boron concentrations (ppm) of tumour, normal liver tissue, or blood is 61.7, 4.3, 0.1, respectively. In the epithermal lneutron dosimetry, the maximum tumour RBE dose, minimum tumour RBE dose, and mean tumour RBE dose are 43.1, 7.3, and 21.8 Gy-Eq, respectively, with the normal liver RBE restriction to 4.9 Gy, in 40 minutes irradiation. In this study, we showed that ~(10)B entrapped WOW emulsion would be applied to novel intra-arterial boron delivery carrier on BNCT to cancer, and, we showed the possibility to apply BNCT to HCC.