Design of a neutron applicator to reduce damage in cardiac implantable electronic devices

The purpose of this study was to design a simple neutron applicator to reduce neutron damage in CIEDs from high energy photon beams. MCNP was used to simulate gantry mounted neutron applicators with different dimensions and composition. Applicator mass was fixed at 10kg and mounted to the wedge accessory mount. Polyethylene and borated polyethylene with different boron weight composition were considered. Using silicon damage response functions, the probability of neutron damage induced in CIEDs was calculated. The applicators reduced the probability of damage to the CIED. The probability of damage was reduced by up to a factor of 3.4 depending on the off axis distance. Applicators with a thickness of 4cm and a boron composition of 3.5% demonstrated the greatest reduction in neutron damage probability. The applicator also reduced the in-field damage probability up to 170%. Using simple neutron applicators can decrease the CIED damage probability both in field and out of field for patients who would benefit from high energy photon therapy.