Determination of proper neutron beam energy spectrum for penetration depth in liver BNCT

Abstract

Cancer treatment with neutron capture in Boron is a recently developed method in treatment of malignant tumor, capable of destroying cancerous cells plus a little side of effect. In BNCT the radiation damage is selectively concentrated according to biodistribution of Boron –carrying molecules. This makes BNCT a viable method in treatment of liver metastatic cancer. In the present study, with the use of ORNL computational phantom and MCNP Monte Carlo Code, an epithermal neutron beam with varying energy between 1eV to 10keV was simulated and the depth-dose curves in healthy tissue for tumors located at 2cm,4cm and 6cm beneath surface were obtained. Two figures of merit was employed to assess the optimum neutron energy: 1- The ratio of tumor absorbed dose to maximum healthy tissue absorbed dose called Therapeutic Gain, 2- The ratio of skin absorbed dose to maximum healthy tissue absorbed dose. This criteria makes possible assessment of epithermal neutron beam quality in liver