Characterization of a novel proton-CT scanner based on Silicon and LaBr$_3$(Ce) detectors

TL;DR

This paper presents a new proton-CT scanner using Silicon and LaBr$_3$(Ce) detectors, demonstrating its ability to produce high-quality images and accurate proton stopping power maps, potentially reducing treatment uncertainties in proton therapy.

Contribution

The work introduces a novel proton-CT scanner with high energy resolution detectors and validates its imaging capabilities and spatial resolution through phantom experiments.

Findings

Scanner achieves spatial resolution better than 2 mm in radiography.

Produces images with below 3 mm resolution in tomography.

RSP mapping quality is comparable to existing state-of-the-art pCT systems.

Abstract

Treatment planning systems at proton-therapy centres generally use X-ray computed tomography (CT) as primary imaging technique to infer the proton treatment doses to tumour and healthy tissues. However, proton stopping powers in the body, as derived from X-ray images, suffer from important proton-range uncertainties. In order to reduce this uncertainty in range, one could use proton-CT images instead. The main goal of this work is to test the capabilities of a newly-developed proton-CT scanner, based on the use of a set of tracking detectors and a high energy resolution scintillator for the residual energy of the protons. Different custom-made phantoms were positioned at the field of view of the scanner and were irradiated with protons at the CCB proton-therapy center in Krakow. We measured with the phantoms at different angles and produced sinograms that were used to obtain reconstructed images by Filtered Back-Projection (FBP). The obtained images were used to determine the capabilities of our scanner in terms of spatial resolution and proton Relative Stopping Power mapping and validate its use as proton-CT scanner. The results show that the scanner can produce medium-high quality images, with spatial resolution better than 2 mm in radiography, below 3 mm in tomography and resolving power in the RSP comparable to other state of the art pCT cameras.