External Radiation Simulation of Linac to Determine Effective Dose in Organs Using Monte Carlo Method

Abstract

The Linear particle accelerator (LINAC) is a tool for radiation therapy that can emit photons and electrons. Radiation of X-ray photons and LINAC electrons is obtained from the interaction of electrons fired into the target plate (tungsten). This radiation can not only affect the target organ but can also affect unwanted organs around the exposure area. Radiation irradiation effects on the organs in the exposure area can be known through simulation of LINAC and phantom radiation processes. Simulation and calculation using Monte Carlo method. This program is operated by MCNPX software. Phantom geometry uses the phantom ORNL MIRD, whereas linac geometry consists of linac blankets, tungsten plates and collimators. Radiation from linac is directed to the left lung as a target and from the simulation results of traces of radical particles shows that radiation emission from linac there are some scattering, but scattering this does not have a significant impact because the amount is not too large. Radiation effect on the organs is indicated by the effective dose quantities in which the left lung has a greater effective dose than the surrounding organs. While the right lung gets a large enough effect from other organs around the target organ. This is because the organ is located close to the target organ and has a smaller type of meeting of the other organs. Not so with the ribs, although it is the first organ exposed to radiation. Radiation that concerns the ribs has no significant effect. This is because of the enormous type of meeting. The effects of radiation on organs are not only influenced by the size of the meeting of organ types but also influenced by the weight factor.