A MONTE CARLO CALIBRATION APPROACH FOR A DUAL-ENERGY CT SYSTEM

This work shows the effectiveness of Monte Carlo methods for calibrating a dual-energy CT (DECT) system on a heterogeneous phantom for radiotherapy. The reference phantom comprising 20 inserts of different materials and densities representing human tissues inserted in a plastic water cylinder has been considered. The reliability of the model, built with the Penelope code, has been verified by comparing the results of the simulations at 80kVp and 140kVp with the experimental data acquired from the CT scans and dosimetry measurements. The effective atomic number from the various materials is also considered a control parameter. Tests for calibration and dose calculation are also based on a homogeneous phantom in PMMA and measurements in air with an ionization chamber. The Monte Carlo simulations coupled with dose evaluations allowed the calibration of the dose deposition effects on the considered tissue models.