Dose Estimation of the BNCT Water Phantom Based on McNPX Computer Code Simulation

Abstract

Cancer is a malignant tumor that destroys healthy cells. Cancer treatment can be done by several methods, one of which is BNCT. BNCT uses 10B target which is injected into the human body, then it is irradiated with thermal or epithermal neutrons. Nuclear reaction will occur between boron and neutrons, producing alpha particle and lithium-7. The dose is estimated by how much boron and neutron should be given to the patient as a sum of number of boron, number of neutrons, number of protons, and number of gamma in the reaction of the boron and neutron. To calculate the dose, the authors simulated the reaction with Monte Carlo N Particle-X computer code. A water phantom was used to represent the human torso, as 75% of human body consists of water. Geometry designed in MCNPX is in cubic form containing water and a cancer cell with a radius of 2 cm. Neutron irradiation is simulated as originated from Kartini research reactor, modeled in cylindrical form to represent its aperture. The resulting total dose rate needed to destroy the cancer cell in GTV is 2.0814×1014 Gy.s (76,38%) with an irradiation time of 1,4414×10-13 s. In PTV the dose is 5.2295×1013 Gy.s (19,19%) with irradiation time of 5.7367×10-13 s. In CTV, required dose is 1.1866×1013 Gy.s (4,35%) with an irradiation time of 2.5283×10-12 s. In the water it is 1.9128×1011 Gy.s (0,07%) with an irradiation time of 1,5684×10-10 s. The irradiation time is extremely short since the modeling is based on water phantom instead of human body.Keywords: BNCT, Dose, Cancer, Water Phantom, MCNPX

Determination of Neutron Flux in Brain Cancer Boron Neutron Capture Therapy Using Monte Carlo Simulation

“…BNCT treatment is carried out by injecting a 10 B carrier agent into cancer cells and irradiating a beam of neutrons. This reaction produces α particles and 7 Li nuclei, and these α particles serve as target cancer cell killers (Ramadhani, et al, 2020). The range of α and Li particles ranges from (8-10) µm to (4.5-5) µm so that the deposited energy is limited only in the size of the cell diameter, which is ±18 µm (Nedunchezhian, et al, 2016).…”