Calibration and GEANT4 Simulations of the Phase II Proton Compute Tomography (pCT) Range Stack Detector

TL;DR

This paper details the calibration of a Phase II proton CT scanner's range stack detector and compares experimental data with GEANT4 simulations to improve proton therapy imaging accuracy.

Contribution

It introduces a calibration procedure for the proton CT scanner’s range stack and validates it through GEANT4 simulation comparisons.

Findings

Calibration procedure established for the range stack detector

Good agreement between experimental data and GEANT4 simulations

Enhanced accuracy in proton range measurements for imaging

Abstract

Northern Illinois University in collaboration with Fermi National Accelerator Laboratory (FNAL) and Delhi University has been designing and building a proton CT scanner for applications in proton treatment planning. The Phase II proton CT scanner consists of eight planes of tracking detectors with two X and two Y coordinate measurements both before and after the patient. In addition, a range stack detector consisting of a stack of thin scintillator tiles, arranged in twelve eight-tile frames, is used to determine the water equivalent path length (WEPL) of each track through the patient. The X-Y coordinates and WEPL are required input for image reconstruction software to find the relative (proton) stopping powers (RSP) value of each voxel in the patient and generate a corresponding 3D image. In this Note we describe tests conducted in 2015 at the proton beam at the Central DuPage Hospital in Warrenville, IL, focusing on the range stack calibration procedure and comparisons with the GEANT~4 range stack simulation.