Speaker
Description
The MATRIX project is pioneering advancements in proton therapy for cancer treatment by developing novel, highly durable detectors that enhance real-time control of irradiation doses, aiming to make treatments faster, more accurate, and reliable. Proton irradiation is one of the most precise cancer therapies available, enabling high-dose tumor targeting while sparing nearby healthy tissue. Currently, high-energy protons (ranging from 65 to 230 MeV) can be detected using various devices, including ionization chambers, scintillators and semiconductor-based detectors. Among these, silicon semiconductor detectors offer high spatial resolution and sensitivity but suffer from rapid degradation under prolonged exposure to high-energy particles, making them unsuitable for long-term monitoring.
To overcome these limitations, the MATRIX team is advancing a breakthrough approach with gallium nitride (GaN) semiconductors, which exhibit approximately ten times greater radiation resistance than traditional silicon. GaN is a robust material widely used in LED technology, making it readily available and cost-effective. This advancement allows for the creation of detector arrays with enhanced longevity and stability. The GaN detector is paired with silicon-based electronics for data acquisition and processing; placed strategically outside the irradiation field to avoid degradation, thus maximizing system durability and performance.
The MATRIX project is producing GaN-based devices with unprecedented capabilities in proton detection, including linear diode arrays of 128 elements and two-dimensional imaging arrays up to 11x11, covering an area of 1 cm² with up to 500 µm spatial resolution. This level of resolution and durability surpasses that of any existing detector systems in proton therapy. Thanks to the microelectronics processes, a much higher resolution can be obtained if needed.
To validate the MATRIX-GaN system, a comprehensive experimental characterization of the GaN diode detectors has been undertaken, including extensive testing in research cyclotrons (such as Cyrcé in Strasbourg) and clinical settings (like the CAL Proton Therapy Center in Nice). These experimental results are cross-referenced with Monte Carlo simulations and benchmarked against established Gafchromic detectors. Further simulations using Geant4/GATE tools are being conducted to assess the array's response efficiency relative to various beam characteristics. The MATRIX system has also undergone rigorous live monitoring, imaging, and long-term irradiation tests to ensure sustained performance and reliability.
The MATRIX GaN sensor represents a transformative leap in proton therapy, serving as the core component of a real-time proton monitoring system. Beyond providing precise control over beam parameters and enhancing dose delivery accuracy, it has the potential to significantly improve imaging resolution, aiding in the development of more effective, individualized treatment plans. This advancement not only marks a technical milestone but also reinforces MATRIX’s commitment to pioneering safer, more effective cancer therapies.
