Novel detector concept for medical gamma probe

Project Information

DETMED

Grant agreement ID: 101129879

DOI

10.3030/101129879

EC signature date 24 August 2023

Start date 1 October 2023

End date 30 September 2027

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 1 651 400,00

Coordinated by

COFAC COOPERATIVA DE FORMACAO E ANIMACAO CULTURAL CRL
Portugal

Periodic Reporting for period 1 - DETMED (Novel detector concept for medical gamma probe)

Reporting period: 2023-10-01 to 2025-09-30

Summary of the context and overall objectives of the project

The DETMED project aims to develop a novel, high-precision gamma probe for radioguided surgeries, significantly improving cancer detection and treatment. By leveraging next-generation silicon photomultipliers (SiPMs) with a buried pixel structure, the project seeks to enhance photon detection efficiency, expand energy detection ranges, and reduce probe size for better surgical maneuverability. This initiative fosters European technological leadership through joint R&D, innovation (R&I), and international multisectoral collaboration, strengthening ties between academia, industry, and medical institutions.
By incorporating advanced semiconductor technology and scintillation materials, DETMED will deliver a gamma probe with higher sensitivity (+40%) and broader energy detection range (2x) compared to existing solutions, thereby advancing the Europe’s Beating Cancer Plan and contributing to next-generation nuclear medicine technologies.
To achieve this goal, the project is structured into six Work Packages (WPs):
WP1: Innovative SiPM Development and Testing
Objective: Development and optimization of buried-pixel SiPMs to achieve high photon detection efficiency, linearity, and radiation resistance.
Results: Fully operational SiPMs with 100% active area, optimized for radioguided surgery applications.
WP2: Scintillation Material Selection and Characterization
Objective: Identify and optimize high-performance scintillators to maximize light yield and detection efficiency.
Results: Protocols for optimal scintillator selection, evaluation of light transfer efficiency, and performance characterization.
WP3: Electronic Circuit and Readout System Development
Objective: Design and fabricate a compact, high-speed signal processing unit for real-time gamma detection.
Results: Functional readout electronics and signal processing software, optimized for integration into the gamma probe.
WP4: Gamma Probe Prototype Assembly
Objective: Construct a fully operational gamma probe prototype, integrating SiPMs, scintillators, and readout electronics.
Results: Miniaturized, high-precision gamma probe suitable for preclinical validation.
WP5: Performance Testing and Calibration
Objective: Validate the gamma probe under realistic environmental and clinical conditions, ensuring accuracy and reliability.
Results: Performance benchmarking in mixed radiation fields and patent application for the innovative detector technology.
WP6: Project Management and Dissemination

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the first year of the DETMED project, significant advancements were made in WP1 (Innovative SiPM Development and Testing) and WP2 (Scintillation Material Investigation and Optimization). In WP1, two types of micropixel avalanche photodiodes (MAPD-3NK and MAPD-3NM) were developed and analyzed, with the MAPD-3NM demonstrating 1.8 times higher amplification, a 100% increase in overvoltage range, and 3.5 times lower dark current, significantly improving photon detection efficiency and signal-to-noise ratio. Additionally, capacitance optimization (200 pF) enhanced charge storage capacity, contributing to greater detector stability. Future improvements focus on further dark current reduction, optimizing the epitaxial layer, and increasing PDE. In WP2, various scintillator materials were studied to determine their compatibility with SiPMs, including plastic scintillators (polystyrene-based), LaBr₃:Ce, and Lead Fluoride (LFS). LaBr₃:Ce emerged as the best candidate, offering superior light yield (~68,000 photons/MeV), fast decay time (~16 ns), and excellent energy resolution (~3% at 662 keV). Plastic scintillators, while cost-effective, showed limited neutron discrimination, whereas LFS demonstrated strong high-energy photon detection capabilities due to its ultrafast timing (~0.5 ns). The optimization of scintillator-SiPM coupling further enhanced light transfer efficiency, contributing to improved gamma detection performance. These developments mark a crucial step toward the creation of a highly sensitive, compact, and efficient gamma probe for medical imaging and radioguided surgery.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

An intensive exchange of researchers within WP1 (Innovative SiPM Development and Testing) and WP2 (Scintillation Material Investigation and Optimization) resulted in several key achievements in radiation detection technology and photodetector engineering, namely:

Development and optimization of next-generation MAPD-3NM SiPMs, achieving a 1.8x amplification factor increase, 100% higher overvoltage range, and 3.5x lower dark current, significantly improving detection efficiency and signal-to-noise ratio.
Advancement in SiPM material engineering, including optimized epitaxial layer design for lower operational voltage and enhanced photon detection efficiency.
Selection and characterization of high-performance scintillation materials, with LaBr₃:Ce demonstrating superior energy resolution (~3% at 662 keV), high light yield (~68,000 photons/MeV), and rapid decay time (~16 ns), positioning it as the most effective material for medical gamma detection.
Enhanced SiPM-scintillator integration, optimizing light collection efficiency and spectral compatibility, ensuring higher sensitivity and precision in gamma-ray detection.
The project: (i) facilitated the transfer of cutting-edge knowledge between research centers, SMEs, and industry leaders across Europe and Associated Countries; (ii) provided effective training for experienced researchers, young scientists, and PhD students in optoelectronics, photodetector engineering, and radiation imaging; (iii) resulted in joint high-impact publications and conference presentations showcasing advancements in SiPM technology and gamma detection; (iv) promoted efficient exchange of data, experimental samples, and methodologies, accelerating innovation cycles; (v) enhanced the utilization of state-of-the-art fabrication and testing equipment among partners; (vi) enabled the implementation of advanced spectrometric analysis techniques across institutions; (vii) established a collaborative network of research centers in semiconductor photodetection, nuclear imaging, and medical diagnostics; (viii) strengthened bi-lateral and multi-national collaborations, paving the way for further advancements in medical gamma probe commercialization and regulatory compliance.

Seminar Baku, Azerbaijan

Logo

Monography

Kick-off meeting, October 2023, Lisbon, Portugal