Abstract
Neutron capture therapy (NCT) is a binary radiotherapy of cancer using the nuclear neutron capture reaction of radiation-producing atoms(sensitizers). In this therapy, compounds can be designed to be biologically inactive, which makes it possible to dose at a large amount to achieve an extremely high concentration required in tumor cells. Boron has been clinically used in treatments of melanoma and brain tumors. While the melanoma has been successfully treated so far, treatment of the brain tumor is still on trial. The key to success in the neutron capture therapy is the control of biodistribution of the sensitizer atoms, boron and gadolinium, including transport through blood-brain barrier, tumor tissue accumulation, intracellular accumulation and subcellular distribution. In this paper, the principle of this therapy, the present status of boron NCT and a challenge to gadolinium NCT are reviewed, mainly focused on the biodistribution of the sensitizer atoms.
