VERIFICATION AND VALIDATION OF DETERMINISTIC RADIATION TRANSPORT NUMERICAL METHODS, CODES, AND NUCLEAR DATA FOR ESTIMATING RADIATION DOSE TO PATIENTS DURING CT SCAN

摘要

The goal of this work is to determine the viability of modeling an important x-ray procedure, the computed tomography (CT) scan of a pregnant woman and her conceptus using a deterministic radiation transport program. A prior experimental study provides the deposited dose as measured in an anthropomorphic phantom, with detectors positioned in the estimated uterine location. In this paper, we first verify the discrete ordinates code TORT3.2 and a suitably constructed multigroup cross section library against the Monte Carlo code MCNP5. Using MCNP, we demonstrate that accounting for the transport of secondary electrons is unnecessary in tissue-equivalent material. After demonstrating proper verification, we proceed to validate the MCNP and TORT simulations against data measured for the CTDI FDA phantom. In the model, the computed edge-to-center dose ratio is within experimental uncertainty, while the computed exposures are less than 35% from the measured values.