Sensitivity Analysis to Neutron Dose at Patient's Organs According to Some Parameters in a LINAC in the Case of a Bladder Treatment

The study of neutron contamination produced around medical linear accelerators was the focus of several research works, in the field, these last years. These contamination neutrons lead to undesirable doses deposited at healthy tissues located at a distance from the target volume. As a consequence, there is an increased risk of developing secondary cancers in patients. Consequently, an attempt has been made, through this work, to evaluate the photo-neutron doses at patient's organs by Monte Carlo (MC) simulation. To this purpose, a geometric MC model of the LINAC was combined with a numerical MC model of the human body. Then, a neutron contamination dose, in the organs of a female patient-specific analytical phantom, was evaluated in the case of a bladder treatment. Thereafter, a sensitivity study was performed to estimate the variation in the different organs of the patient. The achieved results were then compared to those published in the literature.