Accuracy evaluation and acceleration of Monte Carlo simulation of scattered radiation using a high-fidelity mobile X-ray fluoroscopy system model.

A high-fidelity electron-source Monte Carlo model of a mobile C-arm fluoroscopy system was developed using Particle and Heavy Ion Transport code system (PHITS) to evaluate scattered radiation and calculation acceleration. Electrons were injected into the X-ray tube target, and energy spectra, dose profiles, and scattered doses around the tube head and in the room were calculated. Simulated spectra Simulated spectra agreed with the measured spectra with a root mean square error of 0.06 or less, and the simulation-to-measurement ratios of the scattered air kerma from the electron-source simulations were within 20% at every measurement point. In the simulated two-dimensional distributions, the electron-source simulations showed higher scattered doses than the photon-source simulation at heights above 150 cm. The time required to reach 10% statistical uncertainty decreased from 168.28 h to 72.33 h using the dump technique and to 1.25 h, excluding the dump-generation stage, when combined with the weight window method. The method supports characterization of scattered air-kerma distributions relevant to occupational exposure.