Inter-comparison of relative stopping power estimation models for proton therapy.

Theoretical stopping power values were inter-compared for the Bichsel, Janni, ICRU and Schneider relative stopping power (RSP) estimation models, for a variety of tissues and tissue substitute materials taken from the literature. The RSPs of eleven plastic tissue substitutes were measured using Bragg peak shift measurements in water in order to establish a gold standard of RSP values specific to our centre's proton beam characteristics. The theoretical tissue substitute RSP values were computed based on literature compositions to assess the four different computation approaches.

Developing a phenomenological model of the proton trajectory within a heterogeneous medium required for proton imaging.

To develop an accurate phenomenological model of the cubic spline path estimate of the proton path, accounting for the initial proton energy and water equivalent thickness (WET) traversed. Monte Carlo (MC) simulations were used to calculate the path of protons crossing various WET (10-30 cm) of different material (LN300, water and CB2-50% CaCO3) for a range of initial energies (180-330 MeV). For each MC trajectory, cubic spline trajectories (CST) were constructed based on the entrance and exit information of the protons and compared with the MC using the root mean square (RMS) metric.

Scan path optimization with/without clustering for active beam delivery in charged particle therapy.

Purpose: To compare different algorithms to optimize the scanning path in charged particle therapy with quasidiscrete scanning. We implemented a Hybrid Genetic Algorithm with Heuristics (HyGA) and combined it with clustering techniques. The performance was compared to Simulated Annealing (SA) and to commercially available treatment planning system (TPS).

Characterizing the modulation transfer function (MTF) of proton/carbon radiography using Monte Carlo simulations.

Purpose: To characterize the modulation transfer function (MTF) of proton/carbon radiography using Monte Carlo simulations. To assess the spatial resolution of proton/carbon radiographic imaging.

Methods: A phantom was specifically modeled with inserts composed of two materials with three different densities of bone and lung.

Ion radiography as a tool for patient set-up and image guided particle therapy: a Monte Carlo study.

This study investigate the use of ion radiography as a tool for patient set-up and tumor tracking capabilities for image guided particle therapy (IGPT) using Monte Carlo simulations. One pediatric, two lung and one liver cancer patients were considered in this study. For each patient, 230 and 330 MeV proton, and 500 MeV/nucleon carbon ion pencil beams were simulated through their computed tomography (CT) data set using GEANT4.